Color document scanner

[54] COLOR DOCUMENT SCANNER

[75] Inventor: George D. Margolin, Newport Beach, Calif.

[73] Assignee: Photon Devices, Ltd., Newport Beach, Calif.

[21] Appl. No.: 894,612

[22] Filed: Aug. 8,1986

[51] Int. CiS H04N 1/46; G06K 7/10;

G06K 9/20

[52] U.S. CI 382/65; 358/75;

350/96.24; 355/1; 355/4

[58] Field of Search 382/65, 67; 358/75,

358/901; 350/96.24-26.27; 355/1, 4

[56] References Cited

U.S. PATENT DOCUMENTS

4,413,276 11/1983 Hertz et al 358/75

4,490,740 12/1984 Moriguchi 358/75

4,674,834 6/1987 Margolin 355/1

Primary Examiner—James J. Groody
Assistant Examiner—Michael D. Parker
Attorney, Agent, or Firm—Marmorek, Guttman &
Rubenstein

[57] ABSTRACT

A color document scanner is achieved using three optical fiber bundles. Each bundle is linear at the entrance face and merely gathered at the exit face. The linear ends are abutted against one another and aligned across a document to be scanned. The (three) exit faces are abutted against one or more associated sensor arrays with, for example, red, green, and blue filters interposed between the fiber bundles and the sensor array(s). The sensor arrays are operative not only to relate the positions of fibers in the entrance and exit faces of the respective bundles, but also to organize the associated color information with the appropriate scanned line segment.

9 Claims, 2 Drawing Sheets

COLOR DOCUMENT SCANNER

FIELD OF THE INVENTION

This invention relates to color document scanners ^ and more particularly to such scanners employing fiber optic bundles.

BACKGROUND OF THE INVENTION

My copending application Ser. No. 581,085 filed Feb. 17, 1984 and assigned to the assignee of the present application describes a document scanner employing a fiber optic bundle. (The above-identified patent application is incorporated herein by reference.) The bundle j5 has a linear entrance face and a rectangular exit face. The positions of the fibers in the two faces not only are unknown but they bear no predetermined relationships to one another. In other words, the fiber bundle is noncoherent. The fibers at the entrance face, however, are 20 constrained into a linear geometry and the fibers of the exit face are merely gathered randomly into the proper geometry to mate with the desired sensor array or arrays.

The fibers at the exit face are energy coupled in fixed 25 positions with respect to a sensor array which is conveniently an optical random access memory (RAM) or a random access charge injection device (CID). The bundle is made coherent electronically.

Electronic coherence is achieved during an initializa- 30 tion process by moving a beam of light, small compared to the fiber size, in increments along a path at the entrance face which intersects all the fibers in sequence. A software program is operative to store all the addresses of the sensors illuminated for each position of the beam. 35 The software also is operative to determine when maxima occur in the number of illuminated sensors as the beam is moved. The address of a single sensor is selected out of the group of illuminated sensors for each maximum. The sequence of addresses thus identified is reduced to one sensor address per maximum and their address is taken as corresponding to the exit position of a fiber.

In normal operation, a permanent memory is adapted 4J to interrogate only the single sensor at the stored address for each fiber, in the sequence in which it was stored, each time a line of the document is scanned. Thus, only a small subset of the sensor array is addressed leading to high speed operation. It is clear that 50 a non-coherent fiber optic bundle with a sensor array and a permanent memory with the initialized information as described is capable of faithfully reconstructing entrance pixel positions.

BRIEF DESCRIPTION OF AN ILLUSTRATIVE 55 EMBODIMENT OF THE INVENTION

Such a device as described in the above-mentioned copending patent application is adapted for color herein by employing a plurality of such fiber optic arrays in 60 close proximity astride a document to be copied. One fiber bundle is used for each desired color. For the customary color organization, red, green and blue filters are positioned at the exit ends of first, second, and third bundles respectively. The exit ends can be associ- 65 ated with individual sensor arrays. Alternatively, all the exit ends may be energy coupled to a common sensor array defined by a single optical RAM or CID chip.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a schematic diagram of a color document scanner in accordance with this invention.

FIGS. 2 and 6 are enlarged front views of the entrance face of alternative fiber optic subsystem portions of the scanner of FIG. 1,

FIG. 3 is a schematic diagram of a portion of the fiber optic subsystem of the scanner of FIG. 1, and

FIGS. 4 and 5 are schematic block diagrams of portions of the electronic circuit organization of the scanner of FIG. 1.

DETAILED DESCRIPTION

FIG. 1 shows schematically an arrangement for scanning a document in accordance with this invention. The arrangement includes a RAM chip 61 divided into two sections 62 and 63 as is available commercially. Sections 62 and 63 are mated with first, second, and third randomly-bundled fiber arrays. FIG. 2 shows the linear ends of the three fiber arrays designated Rl—RN, Gl—GN, and Bl—BN for red, green and blue respectively. The bundled ends of the respective arrays are abutted against different areas of chip 61 as shown in FIG. 1.

The fiber optic bundle for each color may be made with the exit end of the bundle abutted against or imaged upon a dedicated sensor array. Alternatively, the three arrays may have their respective exit faces abutted against a corresponding dedicated area of a single sensor array. For this latter embodiment, and particularly for color applications, a random access CID of adequate size would be preferred.

Initialization of the fiber entrance face as shown in FIG. 2 is carried out in a manner described in the aboveidentified patent application. Specifically, a slit is employed to pass white light into a narrow area small compared to a fiber size. The slit extends across three fibers one from each of the red, green and blue sets of fibers. The dedicated areas of chip 61 are interrogated separately to determine if a maximum group of illuminated sensors has occurred each time the position of the slit is incremented. A selected address out of each (maximum) group of illuminated sensors is stored for each of the areas corresponding to a color.

The sequence of addresses for each of the chip (color) areas is stored separately in a permanent memory in order to later interrogate only the stored sequence for each such area each time a scan period occurs. The sequences for the respective colors are, for example, concatenated during each scan period so that the sequence corresponding to red (as an example) is interrogated first followed by the sequence corresponding to green. Thereafter, the sequence corresponding to blue is applied. In each instance operation is entirely analogous to that described in the above-identified patent application.

FIG. 3 shows a single fiber optic bundle, say for the color red. The non-linear end of the bundle includes a red color filter 100 of a dichroic material evaporated onto the exit face of the bundle. Of course, the second and third bundles of FIGS. 1 and 2 would, similarly, include like-positioned green and blue filters (not shown).

FIG. 4 shows the linear (entrance) ends of the fibers of the bundles as lines of squares 200 designated blR .. . b3025R for bits 1 through 3025 red. The FIG. also shows the exit face 195, 196 and 197 organized into