FR2570538A1 - Device for reading a data medium, in particular audio cassettes - Google Patents

Abstract

Device 1 for reading a data medium in particular for reading audio cassettes 2A, 2B, 2C, 2D, 2E comprising means detecting the absence of data on one track and ordering the cassette reading to stop and the reading of the next cassette to start. Application to reading audio data.

Description

 The present invention relates to a device for reading information carriers and more particularly cassettes for sound information carriers, such as those commonly found on the market and which are used to reproduce music or lyrics recorded beforehand. .

 The usual cassette players include a case in which is reserved a housing for immobilizing a cassette in a well defined position, drive means for setting in motion a magnetic tape contained in the cassette, a read head in front of which this scrolls. magnetic tape, and various processing means such as amplification or control of volume or tone, which put the signals emitted by the read head in the form suitable for between transmitted to headphones and / or speakers, these The latter may or may not be incorporated into the case. The reader also comprises means for detecting the arrival of the end of the magnetic strip in front of the read head and then controlling an audible or light signal, and / or stopping the operation or rewinding of the tape and a new passage.

 The running time of the tape contained in the usual cassettes is relatively long, of the order of several tens of minutes, and it therefore exceeds the duration of a large number of musical works, and even more that of a song. which rarely exceeds three to five minutes.

 Commercial pre-recorded tapes therefore contain a number of musical works or songs, hereinafter referred to as "songs", separated from each other by brief intervals of silence. For obvious commercial reasons, each cassette generally comprises pieces which all have common points, and for example, are all of the same author, or have the same performer. It follows that, if the user wishes to avoid a certain monotony, during a job of relatively long duration, he must stop the player at the end of a song and change the cassette. These operations require manual intervention and to that they are done satisfactorily the user is obliged to pay close attention towards the end of the song being broadcast, in order to be able to stop the player as soon as this song is finished.

 The object of the present invention is to remove these constraints by providing a cassette player which can automatically stop the playback of a cassette at the end of a song and the start of the playback of a song. located on another cassette. Of course, although we are talking here about cassettes for sound recording, the invention can be applied to other information carriers, such as discs, floppy disks, etc. for sound use or for video use.

The present invention therefore provides a device for reading an information medium comprising one or more tracks (mono or stereo use) on which information is recorded, in particular a sound recording cassette comprising - a shoemaker comprising a housing for maintain the
information carrier in a defined position, - a read head capable of extracting information
contained in the support when it scrolls in front
said head, - drive means for scrolling the support
in front of the read head, - means for processing the information captured
by the read head, - sensitive means at the end of the track on which
information is recorded and capable of transmitting
in response to warning and / or stop signals
or reversing the drive means, - means sensitive to the absence of a support in
said defined portion of the crate, characterized in that - the crate includes housings to maintain
simultaneously several supports, each housing
being associated with a read head, with means
of training specific to this accommodation, and to means
sensitive to the end of the track and the lack of support, - means are provided that are sensitive to the fact that
a media being read, the information is
absent, or do not vary, for a predetermined period
born these means then emit a signal of change
support, - support change signals control stop
of reading the support and reading a
other medium.

 According to preferred methods, the change of media signals control the successive reading stop and reading of all the media located in the housing of the case in a determined order, with return to the first support when the others have all been put successively in reading. The means sensitive to the end of the track also emit, in response to the latter, signals for changing the support. The means sensitive to the absence of a support in said defined position are provided for transmitting a support change signal when an order is read to read the support contained in a housing when this support is absent. a slogan circuit is provided which allows at will or at predetermined intervals to switch the device for a limited time from one support to another and then to return to the initial support. In the case where the device is adapted to video information, there are provided both means sensitive to the absence of sound information and means sensitive to the absence of variation of image information, and the signal medium change is only emitted in the presence of signals transmitted simultaneously by these two sensitive means.

The present invention will now be
explained in more detail using a practical example given without limitation and illustrated by the drawings
that
Fig. 1 is a perspective view of a reader
sound cassette according to the invention,
Fig. 2 is a block diagram of the same
apparatus.

 The example. described relates to a music cassette player comprising a case 1 equipped with five compartments (or drawers) 2A, 2B, 2C, 2D, 2E. Each locker is designed to receive a cassette, and it is equipped with a drive motor 3 and a read head 4, as well as a cassette presence detector 5, and an end detector. track 6. In fact each locker contains a known mechanism known as "autoreverse", which makes it possible to read the two tracks or the four tracks according to the case, contained in the cassette, without turning over this one, and the detector of end of track 6 only beeps when all tracks have been played.

In the following description, the reference of an element of an index will be assigned, depending on the be
A, B, C, D or E to indicate that it is assigned to the corresponding locker 2A, 2B, 2C, 2D, or 2E.

 For the sake of clarity, FIG. 2 only shows the connections between the motor, the read head and the sensors corresponding to rack A. It is obvious that the corresponding bodies of the other lockers are connected in the same way to the other bodies which will be described below.

 It is further provided switches (transistors) 7 on the power supply of each motor and switches (transistors) 8 on the frequency output of each read head.

 The low frequency (LF) signals from the read heads are sent to a level control device 9, then through a preamplifier 10 to output 11 (amplifier, equalizers, mixer).

This arrangement is conventional, apart from the presence of a timed silencer 12 interposed between the level adjustment device and the preamplifier and whose function will be explained below.
The low frequency signals from the read heads are also sent on a "white detection" circuit comprising a filter 13, a threshold device 14 and a white detection logic 15 which can be activated using a manual switch 16. The logic} 5 sends signals to a control block 17 which controls the five switches 7 and the five switches 8.

The control block 17, in addition to the signals
of the circuit receives two of the five end of track detectors 6, and it is connected to the reset circuit
18, and a clock 19.

The operation is as follows, On power up, the control block 17 is put into action by the reset circuit 18 and it starts
the first 3A motor. Low frequency modulation
of the first reader 4A is amplified and sent to output 11. If the switch 16 is open, the cassette of the locker 2A is read to the end, without interruptions.

Then the end of track detector 6A sends a signal to the control unit which switches the device to the cassette
from locker 2B and so on. If the locker 2B does not contain
no cassette, logic 20, on a corresponding signal
of detector 5B, starts clock 19 which advances
switching to locker 2C etc ... If no cassette
is in place, the device is continuously searching.

 If switch 16 is closed, white detection is on. The low frequency modulation is first filtered in the filter 13, to eliminate unwanted frequencies, then, if its level is sufficient, it triggers the threshold detector 14 which switches the logic 15. If the assembly receives modulation for after six seconds (for example) logic 15 is "primed". From this moment, if the modulation goes out for at least three seconds (for example) the logic 15 emits a signal which has the same effects as the signals emitted by the end of track detectors 6.

 To avoid switching noises, the muffler 12 controlled by the cassette presence logic 20 stops the modulation output at the time of switching or searching.

 An additional logic 21, at will put into action by a command 22 and connected to the logic 20 makes it possible to use the rack E in the "slogan" portion.

It allows, regardless of the state of the control block
17, put the locker E in action and switch its modulation to the output.

 The locker which was on the way before continues to turn, but its modulation is not transmitted.

 The example just described involves the use of cassettes, but it is clear that it is possible, without changing the overall scheme, to replace the cassettes with magnetic or optical discs or other media. 'recording.

 It can also be adapted for video recordings. In this case, however, it may be advantageous to provide a double detection of "blanks", on the sound and on the image, so as to avoid switching when the recording comprises images not accompanied by sound, or else sounds illustrating a still image. In the case of the image, the "blank" consists of a stationary image and not an absence of image, and the detector must be adapted to this situation.

 Note that, anyway, one of the advantages of the invention is to trigger the switching without the need to provide a special signal on the recording.

Claims (6)

 1. Device for reading an information medium comprising at least one track on which information is recorded, in particular a sound recording cassette comprising - a shoemaker (1) comprising a housing for holding  the information carrier in a defined position, - a read head capable of extracting information  contained in the support when it scrolls in front  said head, - drive means for scrolling the support  in front of the read head, - means for processing the information captured  by the read head, - sensitive means at the end of the track on which  information is recorded and capable of transmitting  e in response to warning and / or stop signals  or reversing the drive means, - means sensitive to the absence of a support in  said defined portion of the crate, characterized in that - the crate includes housings to maintain simultaneously-  several supports, each housing being associated  to a read head (4), to drive means  suitable for this accommodation (3), and for sensitive means  at the end of the track (6) and in the absence of support (5), - means (13 to 15) are provided which are sensitive to the fact  that, on a medium being read, the information  are absent, or do not vary, for a period of time  predetermined, these means then emitting a signal  change of support, - change of support signals control stop  reading the support, and reading a  other medium.  2. Device according to claim 1, character  se in that the media change signals  control stop reading and reading  successive of all the supports located in the  housing of the boot maker, in a specified order, with  return to the first medium when the others have all been read.  3. Device according to one of claims 1 or 2, characterized in that the means sensitive at the end of the track also emit, in response to the latter, signals for changing the support.  4. Device according to one of claims 1 to 3, characterized in that the means (5) sensitive to the absence of a support in said defined position are open to send a change of support signal when it is sent an order to read the support contained in a housing when this support is absent.  5. Device according to one of claims 1 to 4, characterized in that there is provided a slogan circuit (21, 22) which-allows at will or at predetermined intervals, to switch for a limited time the device from a support or another and then return to the original support.  6. Device according to one of claims 1 to 5 and particularly suitable for the case where the support is adapted to video information, characterized in that there are provided both means sensitive to the absence of sound information and means sensitive to the absence of variation of image information, and in that the medium change signal is only emitted in the presence of signals transmitted simultaneously by these two sensitive means.