DE19939320A1 - Car radio with a memory for audio signals - Google Patents

Abstract

A car radio with a memory in which audio signals can be stored is proposed, the memory being in the form of a hard disk. DOLLAR A A hard disk as an audio signal memory offers the advantage of a high storage capacity, with today's usual hard disks of approx. 8 Gbyte size in the range of 15 hours of audio signal in CD quality, with a small size and low manufacturing costs.

Description

State of the art

The invention is based on a car radio with a memory, in which audio signals can be stored, according to the genus of independent claim.

Car radios with a memory in which audio signals can be stored are known, for example, in the form of car radios with a memory for recording traffic reports from a current radio program. Such a car radio is, for example, the device type "New York RDM 127 " from Blaupunkt-Werke GmbH, Hildesheim, which is described in the brochure with the title "The plus in the car. Mobile communication 1999. " is described. The memory of the device mentioned is designed for recording up to four traffic announcements with a total duration of up to four minutes. Due to the low sampling rate for the audio signal, the memory is only suitable for voice recordings. The device also has a compact disc (CD) player with which standard audio CDs can be played.

Further, for example from the magazine "Plus", booklet 6/99, so-called CD burner for connection to personnel  Computer known, by means of which the user on so-called Blank CDs (CD-R's or CD-RW's), for example, pieces of music can play, what special software on the PC is used. The CDs described by the user are in a manner known per se as well as recorded ones commercially available music CDs in a conventional CD player playable. To copy at least some Puts pieces of music from an audio CD on a CD-R or CD-RW the software on the hard drive of the personal computer so-called image file in which the to be copied Pieces of music are included. The one in the image file Music data contained are then on a CD dubbed, but can also be played back on the PC.

Furthermore, for example from the magazine "Plus", issue 6/99, the possibility is known of compressing audio signals, in particular pieces of music, in digital form by means of the MPEG1 Layer 3 (MP3) standard, ie reducing their data volume. Also known from the magazine mentioned are playback devices for audio data compressed according to the MP3 standard, for example in the form of portable playback devices or also a PC equipped with appropriate decoding software, on the hard disk of which the audio data can be stored.

Finally, for example from the magazine "Plus", Issue 7/99, in the form of the company's Auto PC described there Clarion known a device that both in one housing Functionality of a car radio, as well as that of one Computers united. The device has both a slot for Compact flash cards as data carriers, as well as a CD-ROM Drive on which additional software can be loaded, as well Music CDs are playable.  

Advantages of the invention

The car radio according to the invention with the features of independent claim has the advantage that with a Hard drive as storage for audio, in particular Music signals, a memory with a particularly large one Recording capacity is available.

So are up without special data compression procedures a conventional computer hard drive with currently usual 8 gigabytes of storage capacity music data with one Total duration of a good 15 hours with a usual for CDs Data volume of around 8.8 megabytes per minute in CD Quality can be saved. Using a hard drive as Audio signal memory for a car radio thus has the advantage that with the vast number of all required Driving a change of data medium, as is the case with CDs about every hour, or about one and a half for cassettes Hours, after the full playback of the Disk is common, is unnecessary. This eliminates the Distraction of the driver and thus a potential hazard of the driver himself and other road users through the Change of a data carrier while driving.

This applies all the more when using a Compression method, such as MP3, for storing the Audio data in the memory of the car radio, whereby in the In the case of MP3, the capacity of the hard drive is around that Factor 10 increased to 150 hours of music data, which the Capacity of approximately 128 CDs with one accepted corresponds to an average playing time of 70 minutes per CD. Consequently an entire audio CD collection, or at least considerable parts of one such a collection can be saved. The change of  Under certain circumstances, memory becomes complete dispensable.

Another advantage is the fact that a commercial hard disk compared to a conventional CD Drive has smaller external dimensions. Out of it results in less effort when integrating the Memory in a car radio with its usual today small external dimensions required to hold the radio in a standardized installation slot are specified.

Also to an external one known for car radios connectable so-called CD changer, a CD Player for several CDs inserted in a magazine the hard drive solution the benefit much less Size at least comparable or, especially in the case of MP3 compressed audio data, much larger Capacity. Furthermore, a hard drive is cheaper producible as a CD changer and due to a fewer mechanical components less prone to wear.

For storing audio data in the memory of the car radio it is an advantage if this, like one of PCs known removable hard drive, from the car radio removable or detachable from this and with a Data source, such as a PC or a home audio system is connectable.

It is also used to store audio data in the memory of the Car radios an advantage if this is a reading device for includes other storage media for dubbing on audio signals stored in another storage medium in the memory is connected to the memory. In this case the hard disk can remain in the car radio at all times, or  remain connected to it when placed externally. This is particularly beneficial if the hard drive is either permanently installed in the car radio, or on another Place in the vehicle, for example behind an interior paneling, is permanently installed.

Especially in the case of one that is not or only with considerable effort removable from or from the car radio decouplable hard drive, it is particularly advantageous if a encoder for between the reading device and memory Compression of audio data read from a storage medium can be switched for storage in the memory. In this Case need in case of storing the audio data in the memory in compressed form that of the Storage device to be read not necessary to contain data in already compressed form. Rather, the compression can take place in the car radio, so that conventional audio CDs can also be used as data carriers are. Also, the reader does not have to read Storage media with compressed audio data may be suitable a conventional CD- Player.

A decoder downstream of the memory for implementing the MP3-encoded audio data enables their conversion into playable audio signals.

drawings

Embodiments of the invention are in the figures shown and are explained in more detail below. Same Reference symbols in the figures denote the same Elements.  

Show it

Fig. 1 is a block diagram of the essential part of the invention, a car radio according to the invention,

Fig. 2 is a block diagram of a memory for recording audio data with an upstream encoder for data compression, and

Fig. 3 is a block diagram of a memory for recording audio data to a decoder nachschaltbaren for conversion into a compressed form of stored audio data reproducible in audio signals.

Description of the embodiments

An advantageous exemplary embodiment of a car radio 1 according to the invention is shown schematically in FIG. 1 in the form of a block diagram.

The car radio 1 according to the invention comprises a radio receiver 20 which is known per se and therefore not explained in more detail and which comprises the means required for receiving a radio signal and for demodulating it. At the output of the radio receiver 20 , a radio program signal obtained from a received radio transmission frequency by demodulation is available in the form of a stereo multiplex signal, which contains audio signals for the left and right audio channels.

The radio program signal, that is to say the audio signal to be reproduced, is fed to a first input of a controllable switch 60 . When the switch 60 is suitably controlled by a control signal, the broadcast program signal is at the output of the controllable one. Switch 60 removable.

The output of the controllable switch 60 is connected to a playback device 50 , known per se, for audio signals. This includes, in a manner known per se, the means required for reproducing an audio signal, such as a stereo decoder for isolating the left and right channels of the audio signal from the stereo multiplex signal, a sound influencing device for influencing the frequency response of the audio signal, for example in the form of an equalizer Volume control, one or more low-frequency amplifiers and loudspeakers for playing back the audio signal.

The car radio further comprises an operating unit 40 with operating elements 45 , for example in the form of pushbuttons, rotary knobs or cursor control keys, for operating its functions, and a display unit 70 for displaying its operating state, for example the name of a radio program currently received by the radio receiver. In the case of cursor control of the car radio using cursor keys 45 , the display unit 70 is also used to display a cursor against the background of a one-dimensional or multidimensional selection list, from which functions and parameters of the car radio can be selected or set by selection with the cursor.

Finally, the car radio according to the invention comprises a memory 10 for audio data in the form of a hard disk. The audio data stored on the hard disk can be read out on a corresponding control signal and fed to the second input of the controllable switch 60 . When a corresponding control signal is present at the switch 60 , the latter establishes a connection between its second input and its output and thus with the playback unit 50 , so that the audio signals read out from the memory 10 are played back. The hard disk can be integrated into the car radio or connected to the car radio as an external device.

The elements 10 , 20 , 40 , 50 , 60 , 70 mentioned are connected to a controller 30 for controlling the functions of the device. The control is used, for example

• for converting user inputs on the operating unit 40 into control sequences for controlling the elements of the device mentioned,
• for recording operating states of individual components of the device and for generating operating state information which can be displayed on the display unit 70 , that is to say for MMI functions of the device, and
• - to control internal processes and functions of the car radio 1 .

Functions controlled by the controller 30 are, for example

• After the user has selected a desired radio program, the control unit 40 determines a radio transmission frequency assigned to the program in a program and frequency memory and sets the transmission frequency as the reception frequency on the radio receiver 20 .
• - if the reception of a set one deteriorates Reception frequency determination of an alternative, better receivable broadcast frequency over which the same Program is broadcast, and setting this Transmitting frequency as the receiving frequency on the radio receiver,
• - Display of the received radio program depending of RDS data or the set frequency,  
• - Generation of a control signal for the switch 60 as a function of an input by the user via the control unit 40 , or during a standby mode for traffic radio reception in the event of an audio signal being reproduced from the memory 10 , if a traffic announcement is found in the received radio program for the priority reproduction of the traffic announcement the reproduction of the audio signals from the memory 10 ,
• upon a corresponding input by the user via the control unit 40, generation of control signals for the memory 10 for storing audio data in the memory or for reading audio data from the memory,
• - Generation of control signals for influencing the playback volume or the frequency response for an audio signal to be played back by means of the volume control or the equalizer of the playback unit 50 on corresponding inputs by the user on the control unit 40 .

According to a particularly advantageous embodiment of the invention, the memory 10 of the car radio 1 according to the invention is designed as a hard disk which can be removed from the car radio, for example in the manner of a removable hard disk known from personal computers. For this purpose, it is provided with detachable terminals 12 and 13 for connection to the controller 30 and the second input of the controllable switch 60 , which are advantageously arranged in a plug contact strip such that the terminals 12 and 13 automatically when the hard disk 10 is inserted into the car radio 1 Establish electrical connections with corresponding mating contacts on the car radio 1 .

The hard disk 10 , when removed from the car radio, can be connected to an audio signal system, for example a home stereo system, for transferring audio data to the hard disk via a further connecting terminal 11 , also referred to below as an input connecting terminal. However, it can also be provided that the hard disk 10 is inserted into a PC and written there with audio data. For example, music CDs inserted in a CD-ROM drive of a PC can be read out and the audio data stored on them can be written to the hard disk. In this way, the user of the car radio can, for example, transfer a desired part of his music CD collection onto the hard disk and then listen to it while driving. The transfer of even large amounts of data to the hard drive takes relatively little time due to the high reading speeds of today's CD-ROM drives and the high writing speeds of today's hard drives.

According to a further embodiment of the car radio, this has a reading device for further storage media, for example in the form of a CD player. Its output is connected to the input of the memory 10 , that is to say the hard disk, or can be connected via a connecting terminal 11 , so that audio data read from an audio CD inserted in the CD player 80 can be transferred to the hard disk 10 . This enables the user of the car radio to, for example, transfer part of his CD collection to the hard disk before starting a journey, which can then be listened to while driving. The transfer of the audio data to the hard drive is accelerated by means of a fast CD player. Fast CD players are available in the form of PC CD-ROM drives with currently up to 40 times the reading speed.

In a further advantageous exemplary embodiment of the car radio according to the invention, explained below with reference to FIG. 2, the memory 10 is preceded or can be preceded by a compression stage 17 . This can be looped into the signal path between further connection terminal 11 of the memory 10 and the hard disk 15 , or, as in the present case, can be looped into the signal path as required. The compression stage 17 serves to compress audio signal data supplied via the further connection terminal 11 of the memory 10 , for example according to the MP3 standard. Audio data is thus stored in compressed form on the hard disk 15 as the actual data memory.

In the present exemplary embodiment, the further connection terminal 11 of the memory 10 is connected to a code detector stage 16 , which checks the data signal present at the further connection terminal 11 to determine whether it is already in compressed form. For example, in the case of a PC as the audio data source, the audio data obtained, for example, from the Internet may already be in MP3 format. On the other hand, when audio data is transferred from an ordinary audio CD into memory 10, it can be in uncompressed form. If the audio data is in compressed form, the code detector stage 16 feeds the signal present at the further connection terminal 11 directly to the hard disk 15 for storing it. Otherwise, if the audio data signal present at the further connection terminal 11 is present in an uncompressed form, the code detector stage 16 feeds it to the compression stage 17 for its compression and subsequent storage on the hard disk 15 in compressed form.

In response to a control command at the control connection terminal 12 of the memory 10 , the audio data signal stored in compressed form on the hard disk 15 is read by the latter and fed to a decompression stage 18 . This converts the compressed audio data signal into a decompressed audio data signal, which can be removed at the output terminal 13 of the memory and can be fed to the playback device.

In the embodiment of the memory 10 shown in FIG. 3, it is provided that both non-compressed audio data signals, for example originating from a CD player 80 , and audio data signals compressed according to the MP3 standard, can be fed via the input terminal 11 . These are stored unchanged on the hard disk 15 .

In this exemplary embodiment, the hard disk 15 is connected on the output side to a further code detector stage 19 which is comparable to the code detector stage 16 and which checks an audio data signal read from the hard disk 15 to determine whether it is in a compressed or uncompressed form. If the audio data signal is in compressed form, it is fed to a decompression stage 18 for its decompression. The decompressed audio data signal can then be removed at the output terminal 13 of the memory 10 .

Otherwise, if the audio data are present in uncompressed form on the hard disk 15 , they are fed directly to the output terminal 13 of the memory 10 when they are read out by the further code detector stage 19 .

Both the code detector stages 16 and 19 , as well as the encoder and the decoder 17 , 18, can be part of the memory 10 , in particular in the case of a memory 10 which can be removed from or decoupled from the car radio 1 , as shown in FIGS. 2 and 3 executed and thus be removed from the car radio together with the memory 10 . In this case, the connection terminals 11 and 13 are in the case of the embodiment of FIG. 2 in the signal path before the code detector 16 or after the decoder 18 , in the case of the embodiment of FIG. 3 before the hard disk 15 or after the code detector 19 and the Decoder 18 arranged.

It can also be provided that the elements 16 to 19 mentioned are implemented as part of the actual car radio and thus remain in the car radio even when the memory 10 is decoupled. Then the terminals 11 and 13 are arranged between the code detector 16 and the memory 10 , which is then identical to the hard disk 15 , or between the hard disk 15 and the decoder 18 or further code detector 19 .

Claims (6)

1. Car radio with a memory in which audio signals can be stored, characterized in that the memory ( 10 ) is designed in the form of a hard disk. 2. Car radio according to claim 1, characterized in that the memory ( 10 ) from the car radio ( 1 ) can be removed. 3. Car radio according to one of the preceding claims, characterized in that it comprises a reading device ( 80 ) for further storage media, which is connected or connectable to the memory for transferring audio signals stored on one or more further storage media into the memory ( 10 ). 4. Car radio according to claim 3, characterized by a between the reading device ( 80 ) and memory ( 10 ) switchable encoder ( 17 ) for compressing audio data read from a storage medium for storing it in the memory ( 10 ). 5. Car radio according to one of the preceding claims, characterized by a decoder ( 18 ) for decompression in compressed form in the memory ( 10 ) of stored audio signals. 6. Car radio according to one of the preceding claims, characterized in that the memory ( 10 ) is integrated in the car radio.