CA1259403A - Video apparatus operable in a quiescent state - Google Patents
Video apparatus operable in a quiescent stateInfo
- Publication number
- CA1259403A CA1259403A CA000517290A CA517290A CA1259403A CA 1259403 A CA1259403 A CA 1259403A CA 000517290 A CA000517290 A CA 000517290A CA 517290 A CA517290 A CA 517290A CA 1259403 A CA1259403 A CA 1259403A
- Authority
- CA
- Canada
- Prior art keywords
- signal
- player
- power
- control unit
- video
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B19/00—Driving, starting, stopping record carriers not specifically of filamentary or web form, or of supports therefor; Control thereof; Control of operating function ; Driving both disc and head
- G11B19/20—Driving; Starting; Stopping; Control thereof
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B19/00—Driving, starting, stopping record carriers not specifically of filamentary or web form, or of supports therefor; Control thereof; Control of operating function ; Driving both disc and head
- G11B19/02—Control of operating function, e.g. switching from recording to reproducing
- G11B19/04—Arrangements for preventing, inhibiting, or warning against double recording on the same blank or against other recording or reproducing malfunctions
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B19/00—Driving, starting, stopping record carriers not specifically of filamentary or web form, or of supports therefor; Control thereof; Control of operating function ; Driving both disc and head
- G11B19/02—Control of operating function, e.g. switching from recording to reproducing
- G11B19/06—Control of operating function, e.g. switching from recording to reproducing by counting or timing of machine operations
Abstract
VIDEO APPARATUS OPERABLE IN A QUIESCENT STATE
ABSTRACT
A video player includes a playback head (26) that repeatedly passes in contact with a circular track (A) on a flexible magnetic disk (10) in order to reproduce a still picture on a video display (34). By cycling the player into a special quiescent state after a certain interval elapses without user instructions, excessive disk wear is avoided. While in the quiescent state, the disk drive motor (14) is stopped...immobilizing the disk-to-head interface...and the video display (34) is blanked. If user instructions are received while in this state, the disk drive motor (14) is reenergized and the video display (34) is resumed, showing the still picture displayed prior to interruption. If no user instructions are received during a further interval, the player is shut off.
ABSTRACT
A video player includes a playback head (26) that repeatedly passes in contact with a circular track (A) on a flexible magnetic disk (10) in order to reproduce a still picture on a video display (34). By cycling the player into a special quiescent state after a certain interval elapses without user instructions, excessive disk wear is avoided. While in the quiescent state, the disk drive motor (14) is stopped...immobilizing the disk-to-head interface...and the video display (34) is blanked. If user instructions are received while in this state, the disk drive motor (14) is reenergized and the video display (34) is resumed, showing the still picture displayed prior to interruption. If no user instructions are received during a further interval, the player is shut off.
Description
S~ 3 1 ~
VIDEO_APPARATUS OPERABTE TN A ~UIESCENT STATE
TECHNICAL FIELD
This invention pertalns to the field of S video recording and reproducing apparatus, and especially to appara~us of ~he type that processes signals representative of a s~ill plcture that is recorded on a magnetic medium. More particularly, the invention relates to a video player that reproduces a st~ll picture by repeatedly travers~ng a circular track on a magne~lc disk.
BACKGROUND ART
Video apparatus according to thls invention utilizes a magnet~c disk having a flexlble recording member on whlch a picture is recorded ~s one field of a composite color video signal. A dlsk ordinarlly contains many plctures récorded on separate tracXs. Each picture may be put on the disk by ~ video still camera employlng an electronic imager to capture an image of the still picture. A
recording circuit in the camera transfers, for each picture, ths contents of the lmager to the magnetic disk as, for example, a circular record track cont ining one video field.
The recorded disk is removed from the camera and inserted into a video player to reproduce each recorde~ field as a visible picture. A disk drive motor in the player rapidly rotates the magnetic disk at an angular velocity of 3600 r.p.m., which corresponds to the repetition frequency of a television field. Each revolution of the disk thus generates a playback signal havlng the correc~ field rate for NTSC reproduction. To complete a video frame, the player forms a second fleld from a second pass over the recorded field and interlaces the two fields for reproduction on a Yldeo dlspl~y. Since the dlsplay time for a comple~e frame is one-thirtie~h of a second, the player mus~
repeatedly cycle the same vldeo frame to the dlsplay (one minute oF viewing, for example, corresponds to 3600 passes over the recorded track). U.S. Patent 4,470,076 describes a player of ~hls type, that is, one that presumes continued passage over a s~ngle track for continued viewing of a single picture.
Such con~inued passa~e, however, is not without its problems. The recordlng member includes a magnetic coating on a flexible substrate. A
playbac~ head (PS well as a record head) must remain in intimate contact with the sur~ace of ~hls type of disk for effective playbac~ (or recording3. Too much contact pressure between the head and ~he disk can quickly scrape the track clesr of the magnetlc coating and ruin the disk. Too little contact pressure results in ~n unstable interface and consequently degrades signal outpu~. The disk-to-head contac~, therefore, ~s ordinarily stabilized with minimum contact pressure by using such assists as a grooved guide pl~te to ~erodynamically, and gently, urge the disk to ~he head. Nonetheless, continued passage of the head - over ~he same track will ~pply enough stress and wear to the ma~netic coating to eventually change its magnetic properties and thereby reduce sign21 output (a phenomenon called the Villari effect).
Clearly, a compromise is made between ContQCt pressure and the useable life o~ the disk.
The compromise, unfortunately, often dictates a r~ther short life. Some published work by Sony Corporation shows that after 24 hours of pl~yback over the same track, the signal output has declined ~25~ 3 about one dB, a ~igure found to be acceptable by the Sony authors (see ~he Electronic Still C~mer~ A ~ew Concept in Photography," by N. Kihara et al, I~EE
Transactlons on Consumer Electronics, Yol. CE-28, No. 3, August lg~2, pp. 3Z5-33~). The Sony publication, wh~le not drawing an outright conclusion abou~ performance after 24 hours of use, shows signal output dropping even further. A 0.5 to 1.0 dB additional signal loss is ~bout all that c~n be tolerated in a commercial system (considering that a total loss o~ 3db would mean half the signal power is lost3.
Faced with the likellhood of a serivus wear problem developing after 24 hours of use on one track, it is imperative that disk-to-head contact be kept to ~ useful minimum...useful in the sense that such apparatus ~s in fact being used during the period of disk-to-head contact. For example, if for some reason ~he user should leave the player --SAy j to answer the telephone-- the disk-to-head contact is no longer serv~ng ~ useful purpose. It is also likely that the player could be left on through forge~fulness or lnattention. Wha~ever is done to ~lleviate wear should place little or no demand on 2S the user. The user may feel obliged to answer the telephone but cannot be expected to intervene on behalf of the player anymore than for an ordinary television--which is usu~lly left unattended and operating in such situations.
DISCLOSURE OF THE INVENTION
The invention treats the problem of minimizing disk wear without intervention from the user by cycling the appar~tus into a speci~l quiescent state in which the disk is stopped after a certain lnterval wi~hou~ user input. Even though disk-to-he&d contact may be m~lntained (WhiCh is optional), disk wear is minimized since ~he disX is immobllized wi~h respect to the head. Any su~sequent user input wlthln a further interval (that of the quiescent state) causes the apparatus to resume operation wi~h the same track being ~ccessed as prior to enter~ng the quiescent st~te.
After the quiescent interval elapses without user input, the appar~tus shuts off. In the quiescent state, and until ~he user re~ceivates the apparatus, the apparatus remains mostly powered except for the disk drive. This not only ensures a quick and slmple reactivation but permits a more "hospi~able't user env~ronment~ For example, in the case of a player, the displ~y screen is blanked so ~s to Xeep the partlal shutdown as inconspicious as possible.
Video appar~tus for processing signals representing still pictures according to the invention is char~cterized by means for generating a first power-down signal after a predetermined power interval has elapsed wi~hout any instructions from a control unl~ assoc~ated with ~he apparAtus. In response ~o the first power-down signal a predetermined quiescent interval begins during which ro~ation of the magnetic me~um is stopped. After the quiescent interval elapses ~ second power-down signal ls generated and, in response thereto, the apparatus is ~nactivated. The video apparatus may be a video camera, for which purpose the power interval is a camera operating interval, or a video player, ~or which the power interval i9 a play interval.
A video player according to an embodimen~
of the invention produces still pictures on a video display depending on user selections entered from a ~L25~ 3 con~rol unit. A signal processing circuit included 1n the player opera~es in two modes~ In l~s first mode, a play~ack slgnal recovered from the disk is converted into a first video slgnal for dl~playing a still picture on the dlsplay. In its second mode, a second video signal is generated for displaying some predetermined image (e.g., ~ blank screen~ on the display in lieu of ~he still picture. A system controller in the pl~yer includes timing means for generat~ng a power-down signal after ~ predetermined interval elapses without any selections from the control unlt. Means responsive to ~he power-down signal lnactivates the drive motor that rot~tes the disk and instructs the signal processing circuit to enter the second mode and route the second video signal to ~he display. Thereupon ~he disk come~ to a stop and the display is blanked. The player then assumes a quiescent state in which it is stlll responsive to selections from the user. A selection made by the user during the quiescent statc will reactivate ~he drive motor, thereby regeneratlng a playback signal, and instruct the signal processing circuit ~o return to the first mode and route the first video si8nal--the p~cture--to the dlsplay~
BRIEF D~SCRIPTION OF THE DRAWINGS
The ~nvention will be described with reference to th~ dr~wings, in which:
~igure 1 is a block diagram showing R video disk player arr~nged according to the invention;
Figures 2A and 2B are dlagrams elaborating in particular upon the system controller and signal processing blocks shown by Figure l;
Figure 3 is a diagram showing more detail of the system controller; and Figure 4 is a functlonal flow diagram for a .2~ 3 computer program that may be used wi~h the system controller of Figures 1, Z and 3 to place the play~r in a quiescent state~
BEST MODE FOR CARRYING OUT THE_INVENTION
Figure 1 shows a general diagram of a video disk player incorporatlng a qulescent state and auxiliary features according to the invention.
magnetic disk 10 is attached by i~s hub 12 ~o a disk drive motor 14. A stepper mo~or 16 ~s connecte~ by a reductlon gear 18 to ~ lead screw 20, wh~ch mates with a threaded hole 22 in ~ non-rot~table h~ad block ~4. A playback head 26 is mounted on the head ~lock ~4. The head block 24 is supported ~or movement rAd~ally o~ the disk 10 so that the playback head 26 may be pos~tioned in contact with a selected track on the disk 10, such as a magnetic track ~.
The player includes a system controller 30 `~(enclosed by broken lines~ ~nd a signal processing !20 circuit 32. The prim~ry function of the player is to reproduce ~ pl~ybac~ signal from the selected magnet~c track A and to generate from th~t a video signsl suitable for displ~ying a selected still picture (corresponding to the pl~yback sign~l) on video displ~y 34. For purposes of this invention, the signal processing circuit 32 operates in two modes: in the first mode the oircuit 32 responds to the playb&ck signal sensed by the playback head 26 and produces a first video signal for displaying ~he selected still picture on the video display 34; in the second mode it responds to a control signa1 (BLANK) and produces a second video signal for displaying some predetermined image--normally that of a blank screen--in lieu oF the still plcture.
(The first mode is depicted in Figure 1 by the display 34 bein8 in solid line ~nd lts connection to the circuit 32 ~lso in solid line; the alternative second mode is shown by broken line, both ~s to the same d~splay 34 and its connection to the circuit 32.) The positioning of ~he head 26 in correspondence with the selected track A and the - rotation of the disk 10 are controlled by ~he system controller 30. A system processor 36, residlng in the system controller 30, responds to selectlon ~nstructions from ~n Automatic pl~yback sec~ion 38 and from a control unit 40, which is the user in~erface with the player. The user turns the pl~yer on or off and controls the order of picture viewlng (by orward ~nd reverse buttons) from the control unit 40. As shown here, the control uni~ 40 emits a coded lnfra-red signal 42r which is received by an IR receiver 44 and transmitted to ~he system processor 36. An ~rrangement ~or automatically viewing the pictures on the disk 10, for example, as to the order or ~he time ullotted for displaying each p~cture, is entered via the control unlt 40 ~o an instruction memory 46 $n ~he automatic playbPck section 38. When automatic playback is selected, the prearranged instructions in the lnstruction memory 46 determine the ~rrangement of playback according to an operating program 48. (More entry buttons, or dual functlons ~or the existing buttons, may be desir~ble on the control unit 40 for specifying ~nd en~ering the arrangement for automatic playback).
The player is put into a quiescent state according to the invention upon receipt of a power-down signal PDN from a power-down program 50.
The signal PDN is 8enerated aEter a timer 52 indicates the elapse of a predetermined interval of time (~he play interval) without the syst~m processor 36 receiving any .selections from the control unit 40 or instructions from ~he automatic playback ~ection 38. Should the processor 36 receive a selection (or automatic instructlon) before the signal PDN is generated, i~ sends a reset signal RST to restart the timer 52, which again starts counting from ~he beginning of ~he play in~erval. The play interval is set to such a time, say five minutes, that only in rare situations would no selection ~or instruction) be received while a user is actually vlewing a set of pictures.
Ordinarily, then, the quiescent state would never be invoked during use of the player, and the user would go through the pictures unaware of ~he continuously resetting timer 52.
On the oth~r hand, if no selection (or instruction) is received during the pl~y interval, .;
flnd the power-down signal PDN is generated, the system processor 36 inactivates the drive motor 14 and sends the blanking signal BLANK to the signal ` processing circuit 32. The s~gnal BLANK instructs j the signal processing clrcui~ to enter its second ; 25 mode and produce the second video signal, a pic~ure blanking signal, for the display 34. Meanwhlle the drive motor 14 comes to a stop, the disk 10 therewith, and the head 26 no longer generates a playback signal. Importantly, the head 26--though still ad~acent the surface of the disk 10--is no longer ~raversing the track A and stressin~, or even wearing away, the ma~netic material. In addition, instead of showing an unappealing, noisy raster, the display 34 shows a blank (black) screen, or any other image deslred (for example, from a text _g_ generator).
Once the system processor 36 puts the player into the quiescent state due ~o recelpt of ~he power-down signal PDN, the system processor 35 immediately sends the slgnal RST to restart the timer 52. The timer 52 proceeds to count until a second predetermined interval of tlme (the quiescent interval) has elapsed. Should a selec~ion from the ~ control unit 40 (or an instruction from the auto playback sect~on 38) be received before the second ~nterval has elapsed, the system processor 36 energlzes the drive motor 14 and deactiva~es the blan~ing signal BLANK. The circult 32 then reverts to its first mode during which its sends the first vldeo signal to the dlsplay 34 and shows the selected stlll pic~ure from ~he track A. At the same tlme the timer 52 is reset and starts counting again (toward the elapse of the play interval). The quiescent interval is set to a suitably long time, say one hour, during which the user has an opportunity to resume viewing at the point of interruption.
I~, however, the end of the quiescent interval is reached without receipt of a selection (or an lnstruction~, the player ~s put in~o a semi-powered shutdown in which most, but not all, of the player is deenergized. For this reason a power supply 54 is provided having two powered modes: a pl~yback mode and an off mode. In the playback mode both power lines V and Y' are energized, providing power to the system controller 30 and ~o the signal processing circuit 32, thereby effecting playback.
The power supply 54 is put into the off mode upon receipt of a disable signal P.EN from the system processor 36 (after the quiescent interval has run ~5~3 out). The power supply 54 respon~s to the signal P.EN by deenerglzing the line V, leaving energized only the power line V'. The energized line V' is connected ~o the receiver ~4 and to the processor 36 to interpret and act upon an on/off signal from the control unlt 40 via the receiver 44. This means that all parts o~ the player are deenergized ~xcept those parts necessary to restart the player if the on/off button is actuated from the control unit 40.
The functional routlne for putting the player into the quiesoent state, and then into shutdown, is shown by the flow diagram of Figure 4.
For the example shown, the first predetermined interval (play interval) ls S minutes and the second predetermined interval (quiescent in~erval~ is 55 minutes. The timer 52 is shown in its preferred form as software timing routines 55 and 56. These timing routines are interrupted by a selection (or an instruc~ion) and the flow reverts back to the beginnlng of the d~agr~m. If 5 minutes run out before ~ new selection is entered, the display ls blanked and the drive mo~or stops. Then, if 55 more minutes run out without any selection, the player is turned off. Thereafter, the pl~yer only responds to the on/off selection from the control unit.
However, ~ny selection (~orward, reverse, etc.) other than "on/off~ during the 55 minutes of the quiescent interval turns the drive motor on ~nd returns the last picture to the display.
(Depressing the ~'onloff" button puts the player into the semi-powered shutdown mode.) The user, ln effect, always picks up where viewing left off regardless of the button pushed (except ~he Non/off"
button); thereafter the buttons resume their normal functions and other pictures may be displayed.
~;~5~ 73 Figures 2A and B taken together are a generally more detailed diagram of the player, and in particular of the signal processing circ,uit 32;
Figure 3 shows more detall of the sys~em controller 30, which appears in both Figures 1 and 2A.
Components already discussed in connection with Figure 1 are given llke-numbered reference characters. The playback signal generated by the playback head 26 is, in the preferred embodiment, a low-level, lin~ sequential fm signal which is provided to the input termlnals of a preamplifier and equalization circuit 60. Rf equalization compensates For distortion present in the output voltage from the playback head. The output voltage ~rom the preampli~ier and equallzation circuit 60 is fed to a separation filter 62 for sep~ra~ing the luminance (Y) and chrominance (C) signals ~rom the playback signal. ~e separ3te Y and C signals are ;applied to respectlve limiters 64a and 64b in order `~20 to eliminate amplitude fluctuations. The limited Y
and C fm signals ~re demodul~ted in respective circui~s 66~ ~nd 66b, which ~lso attenuate the higher frequencies (deemphasis) ~ccording to the ~mount ~hat they were intentionslly boosted at recording. It s~ould be reealled that the signal `recorded on the d~sk 10 (track A~ represents one field of a televis~on signal. In order to provide a full-frame signal, the demodulated Y and C signals are applied to a field interlacer 68. As is conven~ional, ~he interlacer 68 intern~lly swltches between two signal paths: one path directly passes the signals ~hrough for one field; the other path ~ncludes a 0.5 H del~y and provides the interlflced field. The luminance signal Y for ad~acent lines of the recorded field may ~e averaged to generate the luminace of each line of ~he in~erlaced fleld~
Ord1narily ~he chrom~n~nce for the lnterl~ced field is ~ust a repeat of the recorded field.
Since the si~nal from ~he disk is line-sequential (th~t ls, ~ pair of color dlfference signals alternate from line to line), it is necessary to store the color difference signal from each line ~nd repeat it for the next line so that both color difference signals are available for subsequent processing. Such ~ store and repeat operation is performed by a chroma repeater 70. The color difference sign~ls R-Y ~nd B-Y ~re then applied to respective cl~mps 7~a and 72b for establishing appropriate dc levels. Meanwhlle the tips of the synchroniz~tion portion of the luminance signal Y ate cl~mped in a sync tip cl~mp 74 and then clipped off the signal in a sync clipper 7~ (an operatlon that is desirable for subsequent encoding~. The clipped luminance signal is then clamped to an ~pproprlate dc level in ~ cl~mp 78.
As will be shown, the clamps 72a, 72b and 78 oper~te on their respec~ive signals whether the player is receiving ~ pl~yback signal ~rom the disk lO or is in the quiescent st&te (and the disk 10 ls stopped).
A playback synchronization signal CS is provided by ~ synchronizatlon sep~rator 80 connected into the path o~ the Y signal. Alternatively a synchronization slgnal CS' is locally-generated by a free-running sync generator 82 and used durlng the quiescent state ~o stabilize the picture on the displ~y 34. Both sync signals are applled ~o the lnput terminals of a switch 84; its output signal is 8 composlte sync signAl CSP necessary for proper generation of an NTSC encoded signal in an encoder ~3~
86. The swi~ch 84 is opera~ed according to the cond~ion of the signal BLANK (also descrlbed in connect~on with Figure 1) recelve~ from the system controller 30. The slgnal BLANK ch~nges state- and 5 toggles th0 switch 84--whenever the head 26 is moving between ~r~cks or when the dlsk 10 is not rotating (the quiescent state~. This inven~ion is especially concerned wlth the la~ter occurrence.
When the signal BLANK ls high because the motor 14 10 ~s off (or the head is be~ween tracks) the swi~ch 84 conducts the locally-generated sync s ignal CS ' through to the encoder 86 (AS ~he playback sync signal CSP). At other times, when the signal BLANK
is low, the switch 84 conducts the playback 15 synchronizatlon signal CS through to the encoder 86 (as the playback sync slgnal CSP).
The clamps 72a, 72b and 78 operate concurrently with the proper sync signal to cl~mp the color difference signals R-Y and B-Y and the t 20 luminance slgnal Y ~t correct dc levels for the encoder 86. The clamps are operated at selected dc levels Ll, L2 and L3 by cl~mp and blanX logic 88 durlng a substanti~l portlon--preferably all--o~ ~he hor~zontal drive interval. Since the sync signAls 25 exist only for a shor~ time at the beginning of the drive interval, a suitably long triggering pulse for the loglc 88 is gener~ted from ~he sync signal CSP
by a horizon~al drive generator 90. The logic 88 also needs to recognize the prssence of the 0.5 H
30 delayed interlace field 1n order to correctly time the clampsj this is done by a signal F from the field interlacer 68. The clamped luminance ~nd color difference slgn~ls ~re formulated into an NTSC
signal by the encoder 86 in rel~tion to timing 35 information provided by the playback sync signal ~5~3 CSP. The encoded vldeo signal ls converted lnto a radio frequency signal by an rf modulator 9Z and sent to the v~deo display 34~
The player is controlled according to user demands by the system controller 30. User selectlons are entered through the hand-held remote unit 40, which has its own battery power source.
The remo~e unit 40 lncludes an infra-red transmi~ter, which generates ~ coded infr~-red signal I~ that radiates through space to ~he receiver 44. The receiver 44 decodes the inpu~
signal IR and provides the decoded user signal REM
IN to the sys~em controller. Pursuant to the appropriate user command, the four motor phase lS signals ~ 4 applied to the stepper mo~or 16 ~hich accordingly steps through its posltions as directed. The lead screw 20 is turned ~nd the head 26 is positioned ad~acent ~ desired track (such as the track A). Meanwh~le, a signal M.E~ provlded to a speed control circuit 94 starts the disk drive motor 14. A tachometer circuit (not shown) monltors the motor speed ~nd, when operating speed is attained, a signal M.LOCK slgnifies that the disk 10 is locked up at correct playback speed.
If the predetermined play interval passes without any lnpu~ from the remote unit 40, then the disk drive motor 14 is deenergized by a signal M.STOP sent to the speed control circuit 94 from the system controller 30. No playback si8nal, consequently, is sensed by the head 26. At the same tlme, the si~nal BLANK is emitted by the controller 30 to the swltch 84, toggling the switch so that the genera~ed sync sign~l CS' forms the signal CSP sent to the encoder 86 (in lieu of the playback sync 3S signal CS). The clamps 72a, 72b and 78 operate during the horizontal drive ln~erYal (from ~he genera~or 90) derlved from the slgnal CSP (that is, the generated sync signal CS'). Thus the generated sync signal CSP occurs substan~ially at horizontal intervals, causing a stable picture to appear on the display 34. With the horizontal drive interval of each signal clamped to black by virtue of the clamps 72a, 72b and 78, and with no video signal coming from the field interlacer 68, the video por~ion of the clamped signals remains at a black level and provides a dark, blank picture on the display 34 The system controller, ~n the meantime, starts timing ou~ the predetermined quiescent interval. If ~he quiescent interval passes without any user input from ~he remote unit 40, then the signal P.EN ~o the power supply 54 changes state and causes the power supply 54 to deenergize the section 54b producing the supply voltage V. This deenergizes the portlon of the player devoted to signal processing and to the drive system. The system controller 30 remai.ns powered from the supply sectlon 54a, which provides `. the supply voltage V'.
The system controller 30 is shown in greater detail ~n Flgure 3. A microprocessor 100 (such as an Intel 8031 mlcroprocessor) provides the central processing capability. Operating programs for the player are stored in a program memory (ROM) 102. Input data is received from the player directly by the microprocessor 100 and by an input buffer 104. Output data is provided to the player by a latch 106 (and could also be provided directly by the microprocessor 100). The four phase slgnals 4 to the stepper motor 16 are 8enerated by a driver 108 pursuant to instructions relayed from the microprocessor 100 through the latch 106. Addresses 3L~5~
and data flre moved back and forth ~hrough a bus struc~ure 110. Memory instructions ~re accessed by addresses la~ched off the bus 110 by an address latch 112. The system controller components are 5 each enabled by respective lines tied to the microprocessor 100~ More par~icularly, the read and write enable lines RD and WR connect to the buffer 104 and the latch 106, respec~1velg, for read and write operations. The address enable ALE and the program store enable llne PSEN enable the address latch 112 and the memory 102, respectively, for external data memory access and external program memory fetch operations. Each componen~ of the system controller 30 is con~inuously powered ~y the section 54a of the power supply 54, though the remainder of the player may be deenergized. A
program of the type shown as a flow diagram in Flgure 4 is stored in the program memory 102 for powering parts o~ the player down (the drive motor 14~ when in the quiescent state and all of the player but the system controller 30 and the receiver 44 when in shutdown.
The player as thus far described assumes that the drive motor 14 stops and ~he head 26 simply stays put in the quiescent state ~e.g., by providing only two of the phase signalg ~ 4). This makes it quite straightforward for the signal processing circuit 32 ~o resume in the firs~ mode (~igure 1) when the motor 14 is restarted, again showing the picture last seen on the display 34.
However, it may be desirable to move the head ~
some parking pos1tion at the edge of the disk or to separate the head from the disk when the drive motor 14 and the player sit in the quiescent state. In such a case, the microprocessor 100, which is normally monitoring track locations anyhow, memorizes the locat~on of the track A (l.e., track 1 or 2, etc.) in its internal (or external) memory.
Then, if play is resumed wlthin the quiescent interval (55 minutes) the mlcroprocessor 100 will eall for this tracX location and slgnal the stepper motor 16 to move the head 26 back to ~he track it was on before playbac~ was ~nterrupted.
The preceding disclosure o~ the operation of the system controller 30 cons~itutes ~ sufficient specifica~ion o~ the operating software for put~ing the player in or out of the qu~escent state ~nd shutdown, and ~or accomplishing ancillary ac~lv~ties (s~ar~ing ~nd restarting R timing routine, producing the blanking signal, providing the stepper motor phase signals, eontrolling the disk drive motor, und the like). ~ programmer of ordinary skill can, from this specification, develop the program code to accomplish the stated operation wlthout engaging in ~0 any un~ue experimentation or effort.
* * * * *
As explained in t~e ~bove parsgraphs, this invention m~kes it possible to conserve dis~ wear by utilizing an effectlve procedure that is relatively inconspicuous to the user. Bein8 keyed to the level o~ ~ctivity of the apparatus, the invention allows normal use of the video apparatus without interventlon (i.e., the power interval regulated by the ~imer is continuously being reset while the user is actively usin~ the appar~tus). If the appar~tus is dormant over a period of time (e.g., 5 minutes), the timer runs out and the quiescent state is automatically entered. ~he dlsk/head interface thus is disabled wlthout demanding anything from the user. This provides an effective way to limlt the -fini~e lifetime of the disk ~o productive uses.
* * * * *
While video ~pparatus according to the invention has been described for use in connect~on with a player, it may ~lso be used in connection ~ith ~ video still cAmera that utilizes a similar type o~ magnetic disX. Though the picture recording takes place during one passage of the camera's recording head over a circular ~rack on the disk, the head w~ll repetitively pass over the same circular are~ prior to takin8 the picture.
According to the invention, a qulescent timer is set when the camera is turned on. Then, i~ the camera's shutter is not rele~sed in, for example, 5 minutes the c~mera enters ~ quiescent state to minimize disk wear 5and to conserve energy7 since ~he camera runs off battery power). The power-consuming part of the camera's electronics, as well as ~ disk motor, are inact1vated. The recording head remains in the recording position and cert~in parts of the electronics (e.g., a mlcroprocessor) remain powered in order to receive and process a "reactivate"
slgnal. A partial depression of the shutter button restores the camera to ~ull operation ~nd the quiescent tlmer is rese~ (e.g., to 5 minutes).
Alternatively, i~ the shutter button was not depressed for, say, 30 minutes, the quiescent state is terminated and the camera ls completely inactivated. The recording head is retracted to a home position (relative the edge of the disk) and all of the electronics is shut of~. The user must resctivAte a main power switch to use the camera ag~in. The c~mera therefore utilizes the elements of the invention, th~t is, the automatic entry of a quiescent state after a first time interval and the automatic termination of the quiescent st~te and inactivation of the apparatus after a second time ~nterval in the qu~escent state. The camera also includes the important option of easily terminating the quiescent state (by lnstructions from ~ control unit, such as a shutter) and reactivating the apparatus anytime during the second interval.
.
VIDEO_APPARATUS OPERABTE TN A ~UIESCENT STATE
TECHNICAL FIELD
This invention pertalns to the field of S video recording and reproducing apparatus, and especially to appara~us of ~he type that processes signals representative of a s~ill plcture that is recorded on a magnetic medium. More particularly, the invention relates to a video player that reproduces a st~ll picture by repeatedly travers~ng a circular track on a magne~lc disk.
BACKGROUND ART
Video apparatus according to thls invention utilizes a magnet~c disk having a flexlble recording member on whlch a picture is recorded ~s one field of a composite color video signal. A dlsk ordinarlly contains many plctures récorded on separate tracXs. Each picture may be put on the disk by ~ video still camera employlng an electronic imager to capture an image of the still picture. A
recording circuit in the camera transfers, for each picture, ths contents of the lmager to the magnetic disk as, for example, a circular record track cont ining one video field.
The recorded disk is removed from the camera and inserted into a video player to reproduce each recorde~ field as a visible picture. A disk drive motor in the player rapidly rotates the magnetic disk at an angular velocity of 3600 r.p.m., which corresponds to the repetition frequency of a television field. Each revolution of the disk thus generates a playback signal havlng the correc~ field rate for NTSC reproduction. To complete a video frame, the player forms a second fleld from a second pass over the recorded field and interlaces the two fields for reproduction on a Yldeo dlspl~y. Since the dlsplay time for a comple~e frame is one-thirtie~h of a second, the player mus~
repeatedly cycle the same vldeo frame to the dlsplay (one minute oF viewing, for example, corresponds to 3600 passes over the recorded track). U.S. Patent 4,470,076 describes a player of ~hls type, that is, one that presumes continued passage over a s~ngle track for continued viewing of a single picture.
Such con~inued passa~e, however, is not without its problems. The recordlng member includes a magnetic coating on a flexible substrate. A
playbac~ head (PS well as a record head) must remain in intimate contact with the sur~ace of ~hls type of disk for effective playbac~ (or recording3. Too much contact pressure between the head and ~he disk can quickly scrape the track clesr of the magnetlc coating and ruin the disk. Too little contact pressure results in ~n unstable interface and consequently degrades signal outpu~. The disk-to-head contac~, therefore, ~s ordinarily stabilized with minimum contact pressure by using such assists as a grooved guide pl~te to ~erodynamically, and gently, urge the disk to ~he head. Nonetheless, continued passage of the head - over ~he same track will ~pply enough stress and wear to the ma~netic coating to eventually change its magnetic properties and thereby reduce sign21 output (a phenomenon called the Villari effect).
Clearly, a compromise is made between ContQCt pressure and the useable life o~ the disk.
The compromise, unfortunately, often dictates a r~ther short life. Some published work by Sony Corporation shows that after 24 hours of pl~yback over the same track, the signal output has declined ~25~ 3 about one dB, a ~igure found to be acceptable by the Sony authors (see ~he Electronic Still C~mer~ A ~ew Concept in Photography," by N. Kihara et al, I~EE
Transactlons on Consumer Electronics, Yol. CE-28, No. 3, August lg~2, pp. 3Z5-33~). The Sony publication, wh~le not drawing an outright conclusion abou~ performance after 24 hours of use, shows signal output dropping even further. A 0.5 to 1.0 dB additional signal loss is ~bout all that c~n be tolerated in a commercial system (considering that a total loss o~ 3db would mean half the signal power is lost3.
Faced with the likellhood of a serivus wear problem developing after 24 hours of use on one track, it is imperative that disk-to-head contact be kept to ~ useful minimum...useful in the sense that such apparatus ~s in fact being used during the period of disk-to-head contact. For example, if for some reason ~he user should leave the player --SAy j to answer the telephone-- the disk-to-head contact is no longer serv~ng ~ useful purpose. It is also likely that the player could be left on through forge~fulness or lnattention. Wha~ever is done to ~lleviate wear should place little or no demand on 2S the user. The user may feel obliged to answer the telephone but cannot be expected to intervene on behalf of the player anymore than for an ordinary television--which is usu~lly left unattended and operating in such situations.
DISCLOSURE OF THE INVENTION
The invention treats the problem of minimizing disk wear without intervention from the user by cycling the appar~tus into a speci~l quiescent state in which the disk is stopped after a certain lnterval wi~hou~ user input. Even though disk-to-he&d contact may be m~lntained (WhiCh is optional), disk wear is minimized since ~he disX is immobllized wi~h respect to the head. Any su~sequent user input wlthln a further interval (that of the quiescent state) causes the apparatus to resume operation wi~h the same track being ~ccessed as prior to enter~ng the quiescent st~te.
After the quiescent interval elapses without user input, the appar~tus shuts off. In the quiescent state, and until ~he user re~ceivates the apparatus, the apparatus remains mostly powered except for the disk drive. This not only ensures a quick and slmple reactivation but permits a more "hospi~able't user env~ronment~ For example, in the case of a player, the displ~y screen is blanked so ~s to Xeep the partlal shutdown as inconspicious as possible.
Video appar~tus for processing signals representing still pictures according to the invention is char~cterized by means for generating a first power-down signal after a predetermined power interval has elapsed wi~hout any instructions from a control unl~ assoc~ated with ~he apparAtus. In response ~o the first power-down signal a predetermined quiescent interval begins during which ro~ation of the magnetic me~um is stopped. After the quiescent interval elapses ~ second power-down signal ls generated and, in response thereto, the apparatus is ~nactivated. The video apparatus may be a video camera, for which purpose the power interval is a camera operating interval, or a video player, ~or which the power interval i9 a play interval.
A video player according to an embodimen~
of the invention produces still pictures on a video display depending on user selections entered from a ~L25~ 3 con~rol unit. A signal processing circuit included 1n the player opera~es in two modes~ In l~s first mode, a play~ack slgnal recovered from the disk is converted into a first video slgnal for dl~playing a still picture on the dlsplay. In its second mode, a second video signal is generated for displaying some predetermined image (e.g., ~ blank screen~ on the display in lieu of ~he still picture. A system controller in the pl~yer includes timing means for generat~ng a power-down signal after ~ predetermined interval elapses without any selections from the control unlt. Means responsive to ~he power-down signal lnactivates the drive motor that rot~tes the disk and instructs the signal processing circuit to enter the second mode and route the second video signal to ~he display. Thereupon ~he disk come~ to a stop and the display is blanked. The player then assumes a quiescent state in which it is stlll responsive to selections from the user. A selection made by the user during the quiescent statc will reactivate ~he drive motor, thereby regeneratlng a playback signal, and instruct the signal processing circuit ~o return to the first mode and route the first video si8nal--the p~cture--to the dlsplay~
BRIEF D~SCRIPTION OF THE DRAWINGS
The ~nvention will be described with reference to th~ dr~wings, in which:
~igure 1 is a block diagram showing R video disk player arr~nged according to the invention;
Figures 2A and 2B are dlagrams elaborating in particular upon the system controller and signal processing blocks shown by Figure l;
Figure 3 is a diagram showing more detail of the system controller; and Figure 4 is a functlonal flow diagram for a .2~ 3 computer program that may be used wi~h the system controller of Figures 1, Z and 3 to place the play~r in a quiescent state~
BEST MODE FOR CARRYING OUT THE_INVENTION
Figure 1 shows a general diagram of a video disk player incorporatlng a qulescent state and auxiliary features according to the invention.
magnetic disk 10 is attached by i~s hub 12 ~o a disk drive motor 14. A stepper mo~or 16 ~s connecte~ by a reductlon gear 18 to ~ lead screw 20, wh~ch mates with a threaded hole 22 in ~ non-rot~table h~ad block ~4. A playback head 26 is mounted on the head ~lock ~4. The head block 24 is supported ~or movement rAd~ally o~ the disk 10 so that the playback head 26 may be pos~tioned in contact with a selected track on the disk 10, such as a magnetic track ~.
The player includes a system controller 30 `~(enclosed by broken lines~ ~nd a signal processing !20 circuit 32. The prim~ry function of the player is to reproduce ~ pl~ybac~ signal from the selected magnet~c track A and to generate from th~t a video signsl suitable for displ~ying a selected still picture (corresponding to the pl~yback sign~l) on video displ~y 34. For purposes of this invention, the signal processing circuit 32 operates in two modes: in the first mode the oircuit 32 responds to the playb&ck signal sensed by the playback head 26 and produces a first video signal for displaying ~he selected still picture on the video display 34; in the second mode it responds to a control signa1 (BLANK) and produces a second video signal for displaying some predetermined image--normally that of a blank screen--in lieu oF the still plcture.
(The first mode is depicted in Figure 1 by the display 34 bein8 in solid line ~nd lts connection to the circuit 32 ~lso in solid line; the alternative second mode is shown by broken line, both ~s to the same d~splay 34 and its connection to the circuit 32.) The positioning of ~he head 26 in correspondence with the selected track A and the - rotation of the disk 10 are controlled by ~he system controller 30. A system processor 36, residlng in the system controller 30, responds to selectlon ~nstructions from ~n Automatic pl~yback sec~ion 38 and from a control unit 40, which is the user in~erface with the player. The user turns the pl~yer on or off and controls the order of picture viewlng (by orward ~nd reverse buttons) from the control unit 40. As shown here, the control uni~ 40 emits a coded lnfra-red signal 42r which is received by an IR receiver 44 and transmitted to ~he system processor 36. An ~rrangement ~or automatically viewing the pictures on the disk 10, for example, as to the order or ~he time ullotted for displaying each p~cture, is entered via the control unlt 40 ~o an instruction memory 46 $n ~he automatic playbPck section 38. When automatic playback is selected, the prearranged instructions in the lnstruction memory 46 determine the ~rrangement of playback according to an operating program 48. (More entry buttons, or dual functlons ~or the existing buttons, may be desir~ble on the control unit 40 for specifying ~nd en~ering the arrangement for automatic playback).
The player is put into a quiescent state according to the invention upon receipt of a power-down signal PDN from a power-down program 50.
The signal PDN is 8enerated aEter a timer 52 indicates the elapse of a predetermined interval of time (~he play interval) without the syst~m processor 36 receiving any .selections from the control unit 40 or instructions from ~he automatic playback ~ection 38. Should the processor 36 receive a selection (or automatic instructlon) before the signal PDN is generated, i~ sends a reset signal RST to restart the timer 52, which again starts counting from ~he beginning of ~he play in~erval. The play interval is set to such a time, say five minutes, that only in rare situations would no selection ~or instruction) be received while a user is actually vlewing a set of pictures.
Ordinarily, then, the quiescent state would never be invoked during use of the player, and the user would go through the pictures unaware of ~he continuously resetting timer 52.
On the oth~r hand, if no selection (or instruction) is received during the pl~y interval, .;
flnd the power-down signal PDN is generated, the system processor 36 inactivates the drive motor 14 and sends the blanking signal BLANK to the signal ` processing circuit 32. The s~gnal BLANK instructs j the signal processing clrcui~ to enter its second ; 25 mode and produce the second video signal, a pic~ure blanking signal, for the display 34. Meanwhlle the drive motor 14 comes to a stop, the disk 10 therewith, and the head 26 no longer generates a playback signal. Importantly, the head 26--though still ad~acent the surface of the disk 10--is no longer ~raversing the track A and stressin~, or even wearing away, the ma~netic material. In addition, instead of showing an unappealing, noisy raster, the display 34 shows a blank (black) screen, or any other image deslred (for example, from a text _g_ generator).
Once the system processor 36 puts the player into the quiescent state due ~o recelpt of ~he power-down signal PDN, the system processor 35 immediately sends the slgnal RST to restart the timer 52. The timer 52 proceeds to count until a second predetermined interval of tlme (the quiescent interval) has elapsed. Should a selec~ion from the ~ control unit 40 (or an instruction from the auto playback sect~on 38) be received before the second ~nterval has elapsed, the system processor 36 energlzes the drive motor 14 and deactiva~es the blan~ing signal BLANK. The circult 32 then reverts to its first mode during which its sends the first vldeo signal to the dlsplay 34 and shows the selected stlll pic~ure from ~he track A. At the same tlme the timer 52 is reset and starts counting again (toward the elapse of the play interval). The quiescent interval is set to a suitably long time, say one hour, during which the user has an opportunity to resume viewing at the point of interruption.
I~, however, the end of the quiescent interval is reached without receipt of a selection (or an lnstruction~, the player ~s put in~o a semi-powered shutdown in which most, but not all, of the player is deenergized. For this reason a power supply 54 is provided having two powered modes: a pl~yback mode and an off mode. In the playback mode both power lines V and Y' are energized, providing power to the system controller 30 and ~o the signal processing circuit 32, thereby effecting playback.
The power supply 54 is put into the off mode upon receipt of a disable signal P.EN from the system processor 36 (after the quiescent interval has run ~5~3 out). The power supply 54 respon~s to the signal P.EN by deenerglzing the line V, leaving energized only the power line V'. The energized line V' is connected ~o the receiver ~4 and to the processor 36 to interpret and act upon an on/off signal from the control unlt 40 via the receiver 44. This means that all parts o~ the player are deenergized ~xcept those parts necessary to restart the player if the on/off button is actuated from the control unit 40.
The functional routlne for putting the player into the quiesoent state, and then into shutdown, is shown by the flow diagram of Figure 4.
For the example shown, the first predetermined interval (play interval) ls S minutes and the second predetermined interval (quiescent in~erval~ is 55 minutes. The timer 52 is shown in its preferred form as software timing routines 55 and 56. These timing routines are interrupted by a selection (or an instruc~ion) and the flow reverts back to the beginnlng of the d~agr~m. If 5 minutes run out before ~ new selection is entered, the display ls blanked and the drive mo~or stops. Then, if 55 more minutes run out without any selection, the player is turned off. Thereafter, the pl~yer only responds to the on/off selection from the control unit.
However, ~ny selection (~orward, reverse, etc.) other than "on/off~ during the 55 minutes of the quiescent interval turns the drive motor on ~nd returns the last picture to the display.
(Depressing the ~'onloff" button puts the player into the semi-powered shutdown mode.) The user, ln effect, always picks up where viewing left off regardless of the button pushed (except ~he Non/off"
button); thereafter the buttons resume their normal functions and other pictures may be displayed.
~;~5~ 73 Figures 2A and B taken together are a generally more detailed diagram of the player, and in particular of the signal processing circ,uit 32;
Figure 3 shows more detall of the sys~em controller 30, which appears in both Figures 1 and 2A.
Components already discussed in connection with Figure 1 are given llke-numbered reference characters. The playback signal generated by the playback head 26 is, in the preferred embodiment, a low-level, lin~ sequential fm signal which is provided to the input termlnals of a preamplifier and equalization circuit 60. Rf equalization compensates For distortion present in the output voltage from the playback head. The output voltage ~rom the preampli~ier and equallzation circuit 60 is fed to a separation filter 62 for sep~ra~ing the luminance (Y) and chrominance (C) signals ~rom the playback signal. ~e separ3te Y and C signals are ;applied to respectlve limiters 64a and 64b in order `~20 to eliminate amplitude fluctuations. The limited Y
and C fm signals ~re demodul~ted in respective circui~s 66~ ~nd 66b, which ~lso attenuate the higher frequencies (deemphasis) ~ccording to the ~mount ~hat they were intentionslly boosted at recording. It s~ould be reealled that the signal `recorded on the d~sk 10 (track A~ represents one field of a televis~on signal. In order to provide a full-frame signal, the demodulated Y and C signals are applied to a field interlacer 68. As is conven~ional, ~he interlacer 68 intern~lly swltches between two signal paths: one path directly passes the signals ~hrough for one field; the other path ~ncludes a 0.5 H del~y and provides the interlflced field. The luminance signal Y for ad~acent lines of the recorded field may ~e averaged to generate the luminace of each line of ~he in~erlaced fleld~
Ord1narily ~he chrom~n~nce for the lnterl~ced field is ~ust a repeat of the recorded field.
Since the si~nal from ~he disk is line-sequential (th~t ls, ~ pair of color dlfference signals alternate from line to line), it is necessary to store the color difference signal from each line ~nd repeat it for the next line so that both color difference signals are available for subsequent processing. Such ~ store and repeat operation is performed by a chroma repeater 70. The color difference sign~ls R-Y ~nd B-Y ~re then applied to respective cl~mps 7~a and 72b for establishing appropriate dc levels. Meanwhlle the tips of the synchroniz~tion portion of the luminance signal Y ate cl~mped in a sync tip cl~mp 74 and then clipped off the signal in a sync clipper 7~ (an operatlon that is desirable for subsequent encoding~. The clipped luminance signal is then clamped to an ~pproprlate dc level in ~ cl~mp 78.
As will be shown, the clamps 72a, 72b and 78 oper~te on their respec~ive signals whether the player is receiving ~ pl~yback signal ~rom the disk lO or is in the quiescent st&te (and the disk 10 ls stopped).
A playback synchronization signal CS is provided by ~ synchronizatlon sep~rator 80 connected into the path o~ the Y signal. Alternatively a synchronization slgnal CS' is locally-generated by a free-running sync generator 82 and used durlng the quiescent state ~o stabilize the picture on the displ~y 34. Both sync signals are applled ~o the lnput terminals of a switch 84; its output signal is 8 composlte sync signAl CSP necessary for proper generation of an NTSC encoded signal in an encoder ~3~
86. The swi~ch 84 is opera~ed according to the cond~ion of the signal BLANK (also descrlbed in connect~on with Figure 1) recelve~ from the system controller 30. The slgnal BLANK ch~nges state- and 5 toggles th0 switch 84--whenever the head 26 is moving between ~r~cks or when the dlsk 10 is not rotating (the quiescent state~. This inven~ion is especially concerned wlth the la~ter occurrence.
When the signal BLANK ls high because the motor 14 10 ~s off (or the head is be~ween tracks) the swi~ch 84 conducts the locally-generated sync s ignal CS ' through to the encoder 86 (AS ~he playback sync signal CSP). At other times, when the signal BLANK
is low, the switch 84 conducts the playback 15 synchronizatlon signal CS through to the encoder 86 (as the playback sync slgnal CSP).
The clamps 72a, 72b and 78 operate concurrently with the proper sync signal to cl~mp the color difference signals R-Y and B-Y and the t 20 luminance slgnal Y ~t correct dc levels for the encoder 86. The clamps are operated at selected dc levels Ll, L2 and L3 by cl~mp and blanX logic 88 durlng a substanti~l portlon--preferably all--o~ ~he hor~zontal drive interval. Since the sync signAls 25 exist only for a shor~ time at the beginning of the drive interval, a suitably long triggering pulse for the loglc 88 is gener~ted from ~he sync signal CSP
by a horizon~al drive generator 90. The logic 88 also needs to recognize the prssence of the 0.5 H
30 delayed interlace field 1n order to correctly time the clampsj this is done by a signal F from the field interlacer 68. The clamped luminance ~nd color difference slgn~ls ~re formulated into an NTSC
signal by the encoder 86 in rel~tion to timing 35 information provided by the playback sync signal ~5~3 CSP. The encoded vldeo signal ls converted lnto a radio frequency signal by an rf modulator 9Z and sent to the v~deo display 34~
The player is controlled according to user demands by the system controller 30. User selectlons are entered through the hand-held remote unit 40, which has its own battery power source.
The remo~e unit 40 lncludes an infra-red transmi~ter, which generates ~ coded infr~-red signal I~ that radiates through space to ~he receiver 44. The receiver 44 decodes the inpu~
signal IR and provides the decoded user signal REM
IN to the sys~em controller. Pursuant to the appropriate user command, the four motor phase lS signals ~ 4 applied to the stepper mo~or 16 ~hich accordingly steps through its posltions as directed. The lead screw 20 is turned ~nd the head 26 is positioned ad~acent ~ desired track (such as the track A). Meanwh~le, a signal M.E~ provlded to a speed control circuit 94 starts the disk drive motor 14. A tachometer circuit (not shown) monltors the motor speed ~nd, when operating speed is attained, a signal M.LOCK slgnifies that the disk 10 is locked up at correct playback speed.
If the predetermined play interval passes without any lnpu~ from the remote unit 40, then the disk drive motor 14 is deenergized by a signal M.STOP sent to the speed control circuit 94 from the system controller 30. No playback si8nal, consequently, is sensed by the head 26. At the same tlme, the si~nal BLANK is emitted by the controller 30 to the swltch 84, toggling the switch so that the genera~ed sync sign~l CS' forms the signal CSP sent to the encoder 86 (in lieu of the playback sync 3S signal CS). The clamps 72a, 72b and 78 operate during the horizontal drive ln~erYal (from ~he genera~or 90) derlved from the slgnal CSP (that is, the generated sync signal CS'). Thus the generated sync signal CSP occurs substan~ially at horizontal intervals, causing a stable picture to appear on the display 34. With the horizontal drive interval of each signal clamped to black by virtue of the clamps 72a, 72b and 78, and with no video signal coming from the field interlacer 68, the video por~ion of the clamped signals remains at a black level and provides a dark, blank picture on the display 34 The system controller, ~n the meantime, starts timing ou~ the predetermined quiescent interval. If ~he quiescent interval passes without any user input from ~he remote unit 40, then the signal P.EN ~o the power supply 54 changes state and causes the power supply 54 to deenergize the section 54b producing the supply voltage V. This deenergizes the portlon of the player devoted to signal processing and to the drive system. The system controller 30 remai.ns powered from the supply sectlon 54a, which provides `. the supply voltage V'.
The system controller 30 is shown in greater detail ~n Flgure 3. A microprocessor 100 (such as an Intel 8031 mlcroprocessor) provides the central processing capability. Operating programs for the player are stored in a program memory (ROM) 102. Input data is received from the player directly by the microprocessor 100 and by an input buffer 104. Output data is provided to the player by a latch 106 (and could also be provided directly by the microprocessor 100). The four phase slgnals 4 to the stepper motor 16 are 8enerated by a driver 108 pursuant to instructions relayed from the microprocessor 100 through the latch 106. Addresses 3L~5~
and data flre moved back and forth ~hrough a bus struc~ure 110. Memory instructions ~re accessed by addresses la~ched off the bus 110 by an address latch 112. The system controller components are 5 each enabled by respective lines tied to the microprocessor 100~ More par~icularly, the read and write enable lines RD and WR connect to the buffer 104 and the latch 106, respec~1velg, for read and write operations. The address enable ALE and the program store enable llne PSEN enable the address latch 112 and the memory 102, respectively, for external data memory access and external program memory fetch operations. Each componen~ of the system controller 30 is con~inuously powered ~y the section 54a of the power supply 54, though the remainder of the player may be deenergized. A
program of the type shown as a flow diagram in Flgure 4 is stored in the program memory 102 for powering parts o~ the player down (the drive motor 14~ when in the quiescent state and all of the player but the system controller 30 and the receiver 44 when in shutdown.
The player as thus far described assumes that the drive motor 14 stops and ~he head 26 simply stays put in the quiescent state ~e.g., by providing only two of the phase signalg ~ 4). This makes it quite straightforward for the signal processing circuit 32 ~o resume in the firs~ mode (~igure 1) when the motor 14 is restarted, again showing the picture last seen on the display 34.
However, it may be desirable to move the head ~
some parking pos1tion at the edge of the disk or to separate the head from the disk when the drive motor 14 and the player sit in the quiescent state. In such a case, the microprocessor 100, which is normally monitoring track locations anyhow, memorizes the locat~on of the track A (l.e., track 1 or 2, etc.) in its internal (or external) memory.
Then, if play is resumed wlthin the quiescent interval (55 minutes) the mlcroprocessor 100 will eall for this tracX location and slgnal the stepper motor 16 to move the head 26 back to ~he track it was on before playbac~ was ~nterrupted.
The preceding disclosure o~ the operation of the system controller 30 cons~itutes ~ sufficient specifica~ion o~ the operating software for put~ing the player in or out of the qu~escent state ~nd shutdown, and ~or accomplishing ancillary ac~lv~ties (s~ar~ing ~nd restarting R timing routine, producing the blanking signal, providing the stepper motor phase signals, eontrolling the disk drive motor, und the like). ~ programmer of ordinary skill can, from this specification, develop the program code to accomplish the stated operation wlthout engaging in ~0 any un~ue experimentation or effort.
* * * * *
As explained in t~e ~bove parsgraphs, this invention m~kes it possible to conserve dis~ wear by utilizing an effectlve procedure that is relatively inconspicuous to the user. Bein8 keyed to the level o~ ~ctivity of the apparatus, the invention allows normal use of the video apparatus without interventlon (i.e., the power interval regulated by the ~imer is continuously being reset while the user is actively usin~ the appar~tus). If the appar~tus is dormant over a period of time (e.g., 5 minutes), the timer runs out and the quiescent state is automatically entered. ~he dlsk/head interface thus is disabled wlthout demanding anything from the user. This provides an effective way to limlt the -fini~e lifetime of the disk ~o productive uses.
* * * * *
While video ~pparatus according to the invention has been described for use in connect~on with a player, it may ~lso be used in connection ~ith ~ video still cAmera that utilizes a similar type o~ magnetic disX. Though the picture recording takes place during one passage of the camera's recording head over a circular ~rack on the disk, the head w~ll repetitively pass over the same circular are~ prior to takin8 the picture.
According to the invention, a qulescent timer is set when the camera is turned on. Then, i~ the camera's shutter is not rele~sed in, for example, 5 minutes the c~mera enters ~ quiescent state to minimize disk wear 5and to conserve energy7 since ~he camera runs off battery power). The power-consuming part of the camera's electronics, as well as ~ disk motor, are inact1vated. The recording head remains in the recording position and cert~in parts of the electronics (e.g., a mlcroprocessor) remain powered in order to receive and process a "reactivate"
slgnal. A partial depression of the shutter button restores the camera to ~ull operation ~nd the quiescent tlmer is rese~ (e.g., to 5 minutes).
Alternatively, i~ the shutter button was not depressed for, say, 30 minutes, the quiescent state is terminated and the camera ls completely inactivated. The recording head is retracted to a home position (relative the edge of the disk) and all of the electronics is shut of~. The user must resctivAte a main power switch to use the camera ag~in. The c~mera therefore utilizes the elements of the invention, th~t is, the automatic entry of a quiescent state after a first time interval and the automatic termination of the quiescent st~te and inactivation of the apparatus after a second time ~nterval in the qu~escent state. The camera also includes the important option of easily terminating the quiescent state (by lnstructions from ~ control unit, such as a shutter) and reactivating the apparatus anytime during the second interval.
.
Claims (15)
1. Video apparatus for processing signals representing still pictures, said apparatus utilizing a magnetic medium on which the signals are recorded on recirculating tracks, said apparatus comprising:
a magnetic head;
means for positioning said magnetic head in contact with a selected track;
a control unit for entering instructions to the apparatus regarding the processing of the signals;
means for supporting the medium for rotation relative to said magnetic head so that said head repeatedly passes a selected track;
means for generating a first power-down signal after a first predetermined interval has elapsed without any instructions from said control unit;
means responsive to said first power-down signal for arresting said rotation of the medium;
means for generating a second power-down signal after a further predetermined interval has elapsed following said first interval;
and means responsive to said second power-down signal for inactivating the apparatus.
a magnetic head;
means for positioning said magnetic head in contact with a selected track;
a control unit for entering instructions to the apparatus regarding the processing of the signals;
means for supporting the medium for rotation relative to said magnetic head so that said head repeatedly passes a selected track;
means for generating a first power-down signal after a first predetermined interval has elapsed without any instructions from said control unit;
means responsive to said first power-down signal for arresting said rotation of the medium;
means for generating a second power-down signal after a further predetermined interval has elapsed following said first interval;
and means responsive to said second power-down signal for inactivating the apparatus.
2. Video apparatus as claimed in Claim 1 further comprising:
means responsive to an instruction entered through said control unit during said further predetermined interval for resuming rotation of the medium;
a timer for counting out said first interval; and means responsive to resumed rotation of the medium for resetting said timer to again start counting said first interval.
means responsive to an instruction entered through said control unit during said further predetermined interval for resuming rotation of the medium;
a timer for counting out said first interval; and means responsive to resumed rotation of the medium for resetting said timer to again start counting said first interval.
3. A video player for producing still pictures on a video display from signals recorded on circular tracks on a magnetic medium, said player comprising:
a playback head for sensing the signals recorded on the medium;
means for positioning said playback head in contact with a selected circular track;
a control unit for entering user selections to the player regarding selected tracks;
means for supporting the medium for rotation relative to said playback head so that said head repeatedly senses a selected track and accordingly generates a playback signal representative of a selected still picture;
means for generating a power-down signal after a predetermined interval has elapsed without any selections from said control unit; and means responsive to said power-down signal for arresting said rotation of the medium and discontinuing generation of said playback signal.
a playback head for sensing the signals recorded on the medium;
means for positioning said playback head in contact with a selected circular track;
a control unit for entering user selections to the player regarding selected tracks;
means for supporting the medium for rotation relative to said playback head so that said head repeatedly senses a selected track and accordingly generates a playback signal representative of a selected still picture;
means for generating a power-down signal after a predetermined interval has elapsed without any selections from said control unit; and means responsive to said power-down signal for arresting said rotation of the medium and discontinuing generation of said playback signal.
4. A video player as claimed in Claim 3 further comprising:
controller means for receiving and processing instructions from said control unit;
signal processing means responsive to said playback signal for generating a video signal suitable for displaying said selected still picture on the video display;
a power supply for selectively energizing said controller means and said signal processing means;
means responsive to the elapse of said predetermined interval for initiating a further predetermined interval;
means for generating a second power-down signal after said further predetermined interval has elapsed; and means responsive to said second power-down signal for inactivating only the part of said power supply that energizes said signal processing means.
controller means for receiving and processing instructions from said control unit;
signal processing means responsive to said playback signal for generating a video signal suitable for displaying said selected still picture on the video display;
a power supply for selectively energizing said controller means and said signal processing means;
means responsive to the elapse of said predetermined interval for initiating a further predetermined interval;
means for generating a second power-down signal after said further predetermined interval has elapsed; and means responsive to said second power-down signal for inactivating only the part of said power supply that energizes said signal processing means.
5. A video player for producing still pictures on a video display from signals recorded on circular tracks on a magnetic medium, said player comprising:
a playback head for sensing the signals recorded on the medium;
means for positioning said playback head in contact with a selected circular track;
a control unit for entering user selections to the player, particularly selections directed to said head positioning means and indicating the identity of the selected track;
drive means for moving the medium relative to said playback head so that said head repeatedly traverses a selected track and accordingly generates a playback signal representative of a selected still picture;
signal processing means responsive in a first mode to said playback signal for generating a first video signal suitable for displaying said selected still picture on the video display and in a second mode for generating a second video signal suitable for displaying a predetermined image on the video display in lieu of said selected still picture;
means for generating a power-down signal after a predetermined interval has elapsed without any selections from said control unit;
means responsive to said power-down signal for inactivating said drive means, thereby arresting said relative movement, and for instructing said signal processing means to enter said second mode and route the second video signal to the display; and means responsive to a selection entered through said control unit for reactivating said drive means and for instructing said signal processing means to route the first video signal to the display.
a playback head for sensing the signals recorded on the medium;
means for positioning said playback head in contact with a selected circular track;
a control unit for entering user selections to the player, particularly selections directed to said head positioning means and indicating the identity of the selected track;
drive means for moving the medium relative to said playback head so that said head repeatedly traverses a selected track and accordingly generates a playback signal representative of a selected still picture;
signal processing means responsive in a first mode to said playback signal for generating a first video signal suitable for displaying said selected still picture on the video display and in a second mode for generating a second video signal suitable for displaying a predetermined image on the video display in lieu of said selected still picture;
means for generating a power-down signal after a predetermined interval has elapsed without any selections from said control unit;
means responsive to said power-down signal for inactivating said drive means, thereby arresting said relative movement, and for instructing said signal processing means to enter said second mode and route the second video signal to the display; and means responsive to a selection entered through said control unit for reactivating said drive means and for instructing said signal processing means to route the first video signal to the display.
6. A player as claimed in Claim 5 further comprising:
a receiver for detecting selections entered into the control unit;
a power supply operative in a playback mode for energizing the player to effect playback and in an off mode for enabling the receiver to detect at least certain selections from said control unit;
means responsive to said first power-down signal for generating a second power-down signal after a further predetermined interval has elapsed without any selections from said control unit; and means responsive to said second power-down signal for inactivating said power supply by placing it in said second mode.
a receiver for detecting selections entered into the control unit;
a power supply operative in a playback mode for energizing the player to effect playback and in an off mode for enabling the receiver to detect at least certain selections from said control unit;
means responsive to said first power-down signal for generating a second power-down signal after a further predetermined interval has elapsed without any selections from said control unit; and means responsive to said second power-down signal for inactivating said power supply by placing it in said second mode.
7. A player as claimed in Claim 5 further comprising:
a memory for storing prearranged instructions which are optionally provided in lieu of selections from said control unit;
means for automatically directing said positioning means to move from track to track according to said prearranged instructions; and said means for generating a power-down signal additionally generates said power-down signal after a predetermined interval has elapsed without receiving any prearranged instructions.
a memory for storing prearranged instructions which are optionally provided in lieu of selections from said control unit;
means for automatically directing said positioning means to move from track to track according to said prearranged instructions; and said means for generating a power-down signal additionally generates said power-down signal after a predetermined interval has elapsed without receiving any prearranged instructions.
8. In a video disk player capable of cycling between a powered state and a semi-powered shutdown, the powered state one in which (a) a magnetic disk is supported for rotation in contact with a playback head for reproducing a playback signal from a track on the disk according to instructions from a control unit and (b) a video picture signal is generated from the playback signal for operating a display, the semi-powered shutdown being a condition in which the player is capable of processing at least some instructions from the control unit, particularly instructions to return the player to the powered state, the improvement of a quiescent state in which the player further comprises:
means for generating a power-down signal after a predetermined time interval has elapsed in the powered state without any instructions from said control unit;
means responsive to said power-down signal for initiating the quiescent state by arresting movement of the disk relative to the head and by replacing the video picture signal with a blanking signal for blanking the display; and means responsive to an instruction from the control unit during the quiescent state for resuming movement of the disk relative to the head and for returning the playback signal to the display.
means for generating a power-down signal after a predetermined time interval has elapsed in the powered state without any instructions from said control unit;
means responsive to said power-down signal for initiating the quiescent state by arresting movement of the disk relative to the head and by replacing the video picture signal with a blanking signal for blanking the display; and means responsive to an instruction from the control unit during the quiescent state for resuming movement of the disk relative to the head and for returning the playback signal to the display.
9. A player as claimed in Claim 8 further comprising means operative in the quiescent state for generating a second power-down signal after a further predetermined interval has elapsed without receiving any instructions from the control unit;
and means responsive to said second power-down signal for putting the player into shutdown.
and means responsive to said second power-down signal for putting the player into shutdown.
10. A player as claimed in Claim 8 further including an automatic display facility responsive to prearranged instructions which are optionally provided in lieu of instructions from the operator control unit, said means for generating a power-down signal therefore generating said signal after either a predetermined interval has elapsed without receiving any instructions from the control unit or a predetermined interval has elapsed without receiving any prearranged instructions from the automatic display facility.
11. A player as claimed in Claim 8 in which said means for generating a power-down signal comprises timing means for counting through said predetermined interval and for providing a timing signal at the end thereof, and means responsive to said timing signal for generating said power-down signal.
12. A video disk player for reproducing pictures on a video display from signals recorded on circular tracks on a flexible magnetic disk, said player comprising:
a playback head for sensing the signals recorded on the disk and providing a playback signal;
a disk drive for supporting the magnetic disk for rotation relative to said head, said disk drive including a drive motor for rapidly rotating the disk;
means for positioning the playback head in contact with a selected track on the disk;
means for generating a first synchronizing signal referenced to said playback signal and a second synchronizing signal from a free-running sync generator;
signal processing means responsive to said playback signal and to said first synchronizing signal for generating a video display signal for reproducing a picture on the display device;
a remote control unit for communicating user track selections to the player;
means for receiving said selections from said remote control unit and utilizing them to control said positioning means;
means for generating a power-down signal after a predetermined time interval has elapsed without any selections from said receiving means;
means responsive to said power-down signal for deenergizing said disk drive motor and for replacing said first synchronizing signal with said second synchronizing signal, said signal processing means then substituting a picture blanking signal in lieu of said display signal; and means responsive to a selection from said control unit for actuating said disk drive motor and regenerating the display signal.
a playback head for sensing the signals recorded on the disk and providing a playback signal;
a disk drive for supporting the magnetic disk for rotation relative to said head, said disk drive including a drive motor for rapidly rotating the disk;
means for positioning the playback head in contact with a selected track on the disk;
means for generating a first synchronizing signal referenced to said playback signal and a second synchronizing signal from a free-running sync generator;
signal processing means responsive to said playback signal and to said first synchronizing signal for generating a video display signal for reproducing a picture on the display device;
a remote control unit for communicating user track selections to the player;
means for receiving said selections from said remote control unit and utilizing them to control said positioning means;
means for generating a power-down signal after a predetermined time interval has elapsed without any selections from said receiving means;
means responsive to said power-down signal for deenergizing said disk drive motor and for replacing said first synchronizing signal with said second synchronizing signal, said signal processing means then substituting a picture blanking signal in lieu of said display signal; and means responsive to a selection from said control unit for actuating said disk drive motor and regenerating the display signal.
13. A video disk player for reproducing still pictures on a video display from a composite color video signal recorded as one field per circular track on a flexible magnetic disk having many such tracks, said player comprising:
a playback head for sensing the composite signal recorded on the disk;
means for urging said playback head into physical contact with a selected track on the disk;
means for supporting the magnetic disk for rotation relative to said head, said supporting means including a drive motor for rotating the disk;
means for separating luminance and chrominance signals from the composite signal;
means for separating a synchronizing component from said luminance signal;
means for generating a substitute synchronizing component;
signal processing means responsive to said separated synchronizing component for generating a video display signal from input signals derived from said luminance and chrominance separating means;
a system controller for operating the player according to externally-generated instructions, said controller generating a power-down signal after a predetermined time interval has elapsed without receipt of said external instructions;
means responsive to said power-down signal for inactivating said drive motor and for routing said substitute synchronizing signal to said signal processing means in lieu of said separated synchronizing signal;
means responsive to said substitute synchronizing signal for clamping the input signals to said signal processing means to dc levels corresponding to a blank display; and means responsive to the receipt of an external instruction for reactivating said drive motor and for rerouting said separated synchronizing signal to said signal processing means.
a playback head for sensing the composite signal recorded on the disk;
means for urging said playback head into physical contact with a selected track on the disk;
means for supporting the magnetic disk for rotation relative to said head, said supporting means including a drive motor for rotating the disk;
means for separating luminance and chrominance signals from the composite signal;
means for separating a synchronizing component from said luminance signal;
means for generating a substitute synchronizing component;
signal processing means responsive to said separated synchronizing component for generating a video display signal from input signals derived from said luminance and chrominance separating means;
a system controller for operating the player according to externally-generated instructions, said controller generating a power-down signal after a predetermined time interval has elapsed without receipt of said external instructions;
means responsive to said power-down signal for inactivating said drive motor and for routing said substitute synchronizing signal to said signal processing means in lieu of said separated synchronizing signal;
means responsive to said substitute synchronizing signal for clamping the input signals to said signal processing means to dc levels corresponding to a blank display; and means responsive to the receipt of an external instruction for reactivating said drive motor and for rerouting said separated synchronizing signal to said signal processing means.
14. Imaging apparatus for recording signals representing pictures on circular tracks on a magnetic medium, said apparatus comprising:
a recording head for recording the signals on the medium;
means for positioning said recording head in contact with a selected circular track;
a control unit for entering user instructions to the apparatus;
means for supporting the medium for rotation relative to said recording head so that said head repeatedly passes a selected track and, when instructed by said control unit, records the signals representative of a selected still picture;
means for generating a first power-down signal after a first predetermined interval has elapsed without any instructions from said control unit;
means responsive to said first power-down signal for arresting said rotation of the medium;
means for generating a second power-down signal after a further predetermined interval has elapsed following said first interval;
and means responsive to said second power-down signal for inactivating the apparatus.
a recording head for recording the signals on the medium;
means for positioning said recording head in contact with a selected circular track;
a control unit for entering user instructions to the apparatus;
means for supporting the medium for rotation relative to said recording head so that said head repeatedly passes a selected track and, when instructed by said control unit, records the signals representative of a selected still picture;
means for generating a first power-down signal after a first predetermined interval has elapsed without any instructions from said control unit;
means responsive to said first power-down signal for arresting said rotation of the medium;
means for generating a second power-down signal after a further predetermined interval has elapsed following said first interval;
and means responsive to said second power-down signal for inactivating the apparatus.
15. Apparatus as claimed in Claim 14 further comprising:
means responsive to an instruction entered through said control unit during said further predetermined interval for resuming said rotation of the medium;
a timer for counting out said first interval; and means responsive to resumed rotation of the medium for resetting said timer to again start counting said first interval.
means responsive to an instruction entered through said control unit during said further predetermined interval for resuming said rotation of the medium;
a timer for counting out said first interval; and means responsive to resumed rotation of the medium for resetting said timer to again start counting said first interval.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US06/776,239 US4717968A (en) | 1985-09-16 | 1985-09-16 | Video player with power-down capability |
| US776,239 | 1985-09-16 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1259403A true CA1259403A (en) | 1989-09-12 |
Family
ID=25106853
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000517290A Expired CA1259403A (en) | 1985-09-16 | 1986-09-02 | Video apparatus operable in a quiescent state |
Country Status (5)
| Country | Link |
|---|---|
| US (1) | US4717968A (en) |
| EP (1) | EP0235275A1 (en) |
| JP (1) | JPS63500969A (en) |
| CA (1) | CA1259403A (en) |
| WO (1) | WO1987001856A1 (en) |
Families Citing this family (29)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2556682B2 (en) * | 1986-07-03 | 1996-11-20 | パイオニア株式会社 | Optical disk device |
| JPH0777446B2 (en) * | 1986-07-25 | 1995-08-16 | ソニー株式会社 | Still image playback device |
| US5225913A (en) * | 1987-04-20 | 1993-07-06 | Asahi Kogaku Kogyo Kabushiki Kaisha | Magnetic recorder and regenerator |
| US5029012A (en) * | 1987-04-20 | 1991-07-02 | Asahi Kogaku Kogyo Kabushiki Kaisha | Magnetic recorder and regenerator |
| US5146347A (en) * | 1987-05-29 | 1992-09-08 | Pioneer Electronic Corporation | Disc player control system for quickly placing disc player in command ready state |
| US5970202A (en) * | 1987-10-16 | 1999-10-19 | Canon Kabushiki Kaisha | Communication apparatus |
| US5402200A (en) * | 1988-02-04 | 1995-03-28 | Conner Peripherals, Inc. | Low-power hard disk drive system architecture |
| US5313344A (en) * | 1988-04-28 | 1994-05-17 | Sanyo Electric Co., Ltd. | Stand-by mode setting/releasing device for video cassette recorder |
| US6097511A (en) * | 1988-09-02 | 2000-08-01 | Canon Kabushiki Kaisha | Video camera with interruption of recording upon detection of improper mounting of interchangeable lens |
| EP0366000B1 (en) * | 1988-10-22 | 1994-03-09 | BASF Aktiengesellschaft | Method and arrangement to avoid read-out errors attributed to wear in a magnetic information storage device |
| JPH02226539A (en) * | 1989-02-24 | 1990-09-10 | Hashimoto Corp | Vtr using endless video tape |
| US5101311A (en) * | 1989-11-09 | 1992-03-31 | Archive Corporation | Tape and mechanism protection methods for DAT drives |
| JP2536980B2 (en) * | 1990-10-01 | 1996-09-25 | インターナショナル・ビジネス・マシーンズ・コーポレイション | Optical disc drive and method for controlling an optical disc drive |
| EP0479533B1 (en) * | 1990-10-02 | 1998-05-27 | Canon Kabushiki Kaisha | Image reproducing apparatus |
| US5345347A (en) * | 1992-02-18 | 1994-09-06 | Western Digital Corporation | Disk drive with reduced power modes |
| US5452277A (en) * | 1993-12-30 | 1995-09-19 | International Business Machines Corporation | Adaptive system for optimizing disk drive power consumption |
| JPH07240882A (en) * | 1994-02-28 | 1995-09-12 | Hitachi Ltd | Television receiver with built-in reproducing device |
| KR100200825B1 (en) * | 1994-03-31 | 1999-06-15 | 윤종용 | Auto power off circuit for picture record and reproduce device |
| JP2858542B2 (en) * | 1994-06-03 | 1999-02-17 | インターナショナル・ビジネス・マシーンズ・コーポレイション | Method and apparatus for reducing power consumption of a computer disk drive |
| US5481733A (en) * | 1994-06-15 | 1996-01-02 | Panasonic Technologies, Inc. | Method for managing the power distributed to a disk drive in a laptop computer |
| JPH0845255A (en) * | 1994-08-03 | 1996-02-16 | Sony Corp | Control method for audio/video system |
| JPH0879681A (en) * | 1994-09-08 | 1996-03-22 | Asahi Optical Co Ltd | Electronic still camera |
| JPH08235761A (en) * | 1994-11-17 | 1996-09-13 | Integral Peripherals Inc | Method for reduction of electric power in disk drive |
| US5682273A (en) * | 1995-06-30 | 1997-10-28 | International Business Machines Corporation | Disk drive for portable computer with adaptive demand-driven power management |
| US5954820A (en) * | 1997-09-26 | 1999-09-21 | International Business Machines Corporation | Portable computer with adaptive demand-driven power management |
| DE19853943B4 (en) * | 1997-11-26 | 2006-04-20 | Vapor Technologies, Inc. (Delaware Corporation), Longmont | Cathode for sputtering or arc vapor deposition as well as apparatus for coating or ion implantation with such a cathode |
| US5997705A (en) * | 1999-04-14 | 1999-12-07 | Vapor Technologies, Inc. | Rectangular filtered arc plasma source |
| US7498587B2 (en) * | 2006-05-01 | 2009-03-03 | Vapor Technologies, Inc. | Bi-directional filtered arc plasma source |
| JP7146445B2 (en) * | 2018-05-18 | 2022-10-04 | キヤノン株式会社 | Electrical equipment and control method for electrical equipment |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3814441A (en) * | 1972-09-21 | 1974-06-04 | Arvin Ind Inc | Recording arm safety lifter |
| JPS52145013A (en) * | 1976-05-27 | 1977-12-02 | Nippon Telegr & Teleph Corp <Ntt> | Magnetic disk device |
| US4458273A (en) * | 1981-04-28 | 1984-07-03 | Iomega Corporation | Magnetic disk drive control apparatus and method |
| JPS5833387A (en) * | 1981-08-21 | 1983-02-26 | Sony Corp | Reproducer of color static picture |
| JPS58148754U (en) * | 1982-03-30 | 1983-10-06 | オリンパス光学工業株式会社 | tape recorder |
| JPS59127266A (en) * | 1983-01-07 | 1984-07-23 | Canon Inc | Information reproducing device |
| JPS6070550A (en) * | 1983-09-27 | 1985-04-22 | Shin Kobe Electric Mach Co Ltd | Disc device |
| JPS60177466A (en) * | 1984-02-22 | 1985-09-11 | Sharp Corp | Control system of floppy disc drive |
-
1985
- 1985-09-16 US US06/776,239 patent/US4717968A/en not_active Expired - Fee Related
-
1986
- 1986-09-02 CA CA000517290A patent/CA1259403A/en not_active Expired
- 1986-09-04 EP EP86905613A patent/EP0235275A1/en not_active Ceased
- 1986-09-04 WO PCT/US1986/001811 patent/WO1987001856A1/en not_active Application Discontinuation
- 1986-09-04 JP JP61504919A patent/JPS63500969A/en active Pending
Also Published As
| Publication number | Publication date |
|---|---|
| WO1987001856A1 (en) | 1987-03-26 |
| JPS63500969A (en) | 1988-04-07 |
| EP0235275A1 (en) | 1987-09-09 |
| US4717968A (en) | 1988-01-05 |
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