JPS61170957A - Optical card reader - Google Patents

Abstract

PURPOSE:To shorten the reproduction time and to improve the reproduction speed while data is securely read by supplying the output of a high speed drive circuit to a motor during a period when the scan except a specific one is executed plural times. CONSTITUTION:During a scan period S4 when the output pulse B of a comparator 42 is 'Hi', a gate 43 is opened and the specifid scan is selected. On the other hand, a switch 52 is in the connected state reverse to that as shown in figure, and the constant speed drive pulse of the prescribed interation frequency fs is supplied to the motor 2m from a constant speed drive circuit 54 to transport an optical card at the prescribed speed. When the output pulse B of the comparator 42 rises, a pulse generating circuit 51 generates a switching pulse C with said pulse B as a trigger, and switches the switch 52 to the state as shown in figure. Then the high speed drive pulse of an interation pulse fF larger several times the frequency fs is supplied to the stepping motor 2m from a high speed drive circuit 53, and the optical card is transported at a high speed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to each track of an optical card in which an information signal is recorded on each of a plurality of parallel trunks so as to be optically readable by an array of optical recording traces. The present invention relates to an optical card reading device that optically reads information signals from a card.

[Conventional technology]

As shown in FIG. 4, a so-called memory card or software card is formed on a rectangular card (11) with a plurality of mutually parallel tracks T perpendicular to its reference end surface (la), and each track T has a In each case, the information signal is recorded so as to be optically readable by an optical recording trace, for example, an array of pits P, as shown in FIG.

An optical card reading device that reads information signals recorded in each trunk T from such a card (1) is as follows:
As shown in FIGS. 6 and 7, a card (1) inserted into the device includes a motor roller (not shown), a card feeding mechanism (2) represented by a roller, and a reference end surface (1) of the card (1). Light (5) from an illumination light source (4), such as a light emitting diode, directed in the direction of arrow (3) along 1a)
enters the track T of the card (1) through the conden lens (6), and the reflected light from the track T, that is, the continuation light (7) of the track T, passes through the imaging lens (8). It is projected onto the photodetecting element αω held on the holding plate (9) and detected by the element Ql. On the photodetection element side, a plurality of detection elements (10a) are arranged in a straight line like a CCD (1! charge coupling element) line sensor.
The image projected onto this is read by electrical scanning, and as shown in FIG. The image P' of all the pits of the truck is element a
Images are simultaneously formed on Φ, so that information signals for one track can be read at once.

The electrical configuration of a conventional optical card reading device is, for example, as shown in FIG. The corresponding transfer element (10t) is connected to the gate (
10g).

First, the gate (10g) is opened for a certain period (i!
The zero-order gate (10g) stored in
10t) in parallel, and the light receiving element (10r
) starts to accumulate charge again. Each transfer requires 1 (10
The charge transferred to t) is scanned by a scanning signal (read clock) from the scanning circuit (31),
It is read out as a serial signal during a certain period (scanning period).

Note that since the accumulation period and the scanning period are the same time and timing, the term scanning period (scanning) will be used in the following description.

The readout signal that is the output of the photodetection element αω is a discrete analog signal for each detection element (10a), and after being amplified to a predetermined level by the amplifier (32), it is sent to the sample and hold circuit (33) and the low frequency band. After passing through the filter (34), it is converted into a continuous analog signal and sent to the comparator (
35). The human input signal to the comparator (35) is binarized by comparing whether the voltage is higher or lower than the reference voltage, and the binarized readout signal is
L (36) and the data reproduction circuit (37). P
In LL (36), the clock signal is extracted and reproduced,
This clock signal is supplied to a data reproducing circuit (37) to reproduce binary data. The reproduced binary data is supplied to the data processing circuit (38) and is appropriately processed using the clock signal from the PLL (36).

As mentioned above, during reading, the optical card is fed in a direction perpendicular to the tracks, and the images of each track projected onto the photodetecting elements are read out by electrical scanning.

Now, as shown in FIG. 1O, three pits Pc, P2, . Regarding P3, the amount of incident light on a specific photodetecting element corresponding to peers PI to P3 changes periodically as shown in FIG. 11 in accordance with the feeding of the card. That is, the amount of incident light is the pit Ps, P2
The center of the projected image of P3 and P3 reaches a maximum at time tc1+tc2 and tca when the center coincides with the center of the photodetection element, and the middle part of each pit is projected onto the photodetection element, in other words, the time tG"l The minimum value is reached at an intermediate time point t at and at an intermediate time point t 112 between time points tc2 and tea.

However, the scanning period of the track to which pit P2 belongs is
Between the time t02 when the photodetection output is at its maximum and the time t*x at which the photodetection output is at its minimum to t112, the readout signal obtained from the photodetection element includes:
An invalid component due to the projected image of the intermediate portion between the adjacent track is included, and the contrast of the pit-corresponding signal due to the projected image of the pit is deteriorated. Also, the scanning timing may be shifted for some reason, and the scanning period may be tC1 to tc2 or tc2 to t.
When it becomes like c3, the information recorded on two tracks is read out at the same time, which is equivalent to a state in which two tracks overlap, and the correct recorded information cannot be read out.

In order to solve the problems of conventional optical card reading devices as described above, the applicant scans one track of an optical card multiple times and selects one specific scan from the multiple scans. We proposed an optical card reading device that does this.

Hereinafter, an example of a previously proposed optical card reading device will be described with reference to FIGS. 12 to 14.

The configuration of the previously proposed device is shown in FIG. In FIG. 12, parts corresponding to those in FIG. 9 are designated by the same reference numerals and redundant explanation will be omitted.

In FIG. 12, a peak hold circuit (41) is supplied with a continuous analog signal from a low pass filter (34). The output of the peak hold circuit (41) is supplied to a level detection comparator (42). The output of the comparator (42) is supplied to a gate (43) interposed between the data reproducing circuit (37) and the data processing circuit (38).

The operation of the previously proposed device is as follows. In the previously proposed device, the recent photodetection element and optical system have been improved and the resolution has improved, so here we will introduce 1 in the photodetection element.
Several photodetecting elements are made to correspond to each pit. The length of the scanning period by the scanning circuit (3I) and the card feeding speed by the roller (2) are determined so that one track is scanned several times according to this resolution. As a result, the relative position of one bit P2 and the corresponding photodetection element S of i 191 in each scanning period is shifted by 1゛6°-tLz, as shown by So''Sv in FIG. &B3”°01°1・1°7) P2
.

Depending on the relative position of So, as shown in Figure 14A,
S2 and S6 are lowest at S4, highest at S4, and the edge of the pit crosses the center of the photodetector element.
The average value is obtained at . The same applies to other tracks.

Since the peak value of the readout signal obtained from the photodetector in each scanning period is nothing but the level shown in FIG.
) is the same as that shown in FIG. 14A. If the reference voltage of the comparator (42) is made to match the highest value of this output signal 0 (corresponding to S4 in Fig. 13), the output signal ■ of the comparator (42) will be
As shown in , the output signal of the peak hold circuit (41) becomes "old" in the l scanning period S4 when it reaches its maximum value, and
The comparator (42) detects a specific scan S4 in which the output of the photodetecting element a is at the highest level during a plurality of scanning periods excluding S4. The output signal ■ of the comparator (42) is supplied to the gate (43), and the gate (43) is connected to the peak hold circuit (41).
) during the l scanning period (first
As is clear from FIG. 14A, accurate data stably reproduced by the data reproducing circuit (37) from the high contrast readout signal is transferred to the data processing circuit (38). ) will be forwarded to
Reliable data processing is performed.

Furthermore, in the proposed device, each track is scanned multiple times, so even if the timing of scanning is shifted, the information on two tracks is not read out at the same time as in the conventional method.

[Problem that the invention seeks to solve]

However, in the previously proposed device, each track is scanned multiple times and one specific scan is selected from these multiple scans, so the unselected multiple scans do not contribute to the reproduction of recorded information. However, the problem of unnecessarily lengthening the playback time and slowing down the playback speed has arisen.

In view of the above, an object of the present invention is to provide an optical card reading device that can perform reliable reading while shortening the playback time and improving the playback speed.

[Means for solving problems]

The present invention uses an optical card (11) in which information signals are recorded on a plurality of parallel tracks T so as to be optically readable by an array of optical recording traces P, and the optical card includes a motor (2 m). a feeding mechanism (2);
A plurality of detection elements (10a) are arranged in a straight line, including a photodetection element 01 that detects the reading light of the track T of the optical card (11), and this photodetection element αω is electrically connected multiple times per track T. Scanning means (3) to scan and obtain an output signal
1) and the output of the photodetecting element side, the photodetecting element al
A switch (52) whose connection state is changed based on the output of the specific scan detection means (42); This switch (52
) are provided with a high-speed drive circuit (53) and a constant-speed drive circuit (54) respectively connected to a pair of fixed contacts (52a) and (52b) of the switch (52), and a motor is connected to a movable contact (52c) of the switch (52). (2m) is connected, and at least during the specific scan period detected by the specific scan detection means (42), the output of the constant speed drive circuit (54) is supplied to the motor (2m). This is an optical card reading device in which the output of the high-speed drive circuit (53) is supplied to the motor (2+w) during a plurality of scanning periods except for the period .

[Effect]

According to the present invention, the optical card is fed at a constant speed during at least a specific scanning period, and is fed at a high speed during multiple scanning periods excluding the specific scanning period.

〔Example〕

Hereinafter, with reference to FIGS. 1 to 3, an embodiment of an optical card reading device according to the present invention will be described.
6. The configuration of an embodiment of the present invention is shown in FIG. In FIG. 1, parts corresponding to FIGS. 9 and 12 are designated by the same reference numerals, and redundant explanation will be omitted.

In FIG. 1, (51) is a switching pulse generating circuit, which is supplied with the output (2) of the comparator (42) and generates a pulse for switching the connection state of the switch (52). (53) and (54) are high-speed and constant-speed drive circuits, which are connected to one and the other fixed contacts (52a) and (52b) of the switch (52), respectively.

The common contact (52c) of the switch (52) is connected to a card feeding motor (a stepping motor is acceptable) (
2m) is connected.

The operation of this embodiment is as follows. In a scanning period S4, as shown in FIG. 2B, in which the output pulse (2) of the comparator (42) is "old", the gate (43) is opened and a specific scanning period is selected.

On the other hand, the switch (52) is in a connected state opposite to that shown in the figure, and a constant speed drive pulse having a predetermined repetition frequency rs is supplied to the motor (2+w) from the constant speed drive circuit (54) through the switch (52). Cards are fed at a predetermined speed.

When the output pulse (■) of the comparator (42) falls, the pulse generating circuit (51) uses this as a trigger to generate a switching pulse O, as shown in FIG.
) to the connection state shown. And ＾ speed drive circuit (
53), the repetition frequency fF is several times the frequency fs mentioned above.
A high speed drive pulse of is fed to the stepper motor (2m) via a switch (52) and the optical card is fed at a speed f p / f 5 times the playback speed.

The circuit constants and other parameters of the switching pulse generation circuit (51) are adjusted such that the switching pulse O continues from the scanning period S5 immediately after the specific scanning period S4 to the scanning period S2 two scan periods before the specific scanning period S4 of the next track. If set, the specific scanning period S4 and the immediately preceding scanning period S3 are scanned at a predetermined speed, and the recorded information is reliably read.
The playback time for scanning from to 82 is f 3 / f
It can be shortened to p.

FIG. 3 is a time chart showing how the playback time is shortened, and A, B, and C in the figure correspond to A in FIG. 2.

Corresponding to B and C, respectively, the first peak hold time II
The waveforms of the output (41), the output (4) of the comparator (42), and the output O of the switching pulse generation circuit (51) are shown.

In this embodiment, the specific scanning period was selected by detecting the output level of the photodetecting element, but if a card having marks on the extension of the track is used, the selection may also be based on detecting the marks. .

Moreover, various modifications are possible, such as using a DC motor as the motor (2a+).

〔Effect of the invention〕

As described in detail above, according to the present invention, a photodetector is scanned multiple times per track, and it is detected that the output of the photodetector is in a specific state, and then As the card is read, the card feeding motor is driven at high speed except during a specific scanning period, so that correct recorded information can be read stably and the playback time can be shortened.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an embodiment of an optical card reading device according to the present invention, FIGS. 2 and 3 are diagrams and time charts for explaining the same, and FIGS. 4 and 5 are diagrams showing an embodiment of the optical card reading device according to the present invention. FIGS. 6, 7, and 9 are a plan view of an optical card used for explanation and an enlarged view of its essential parts; FIGS. 10 and 11 are diagrams for explaining the conventional device, FIG. 12 is a block diagram showing the configuration of the already proposed optical card reading device, and FIGS. 13 and 14 are diagrams for explaining the same. It is a diagram.

Claims (1)

[Scope of Claims] An optical card feeding mechanism that uses an optical card in which information signals are recorded on a plurality of parallel tracks so that they can be optically read by an array of optical recording traces, and that includes a motor; Multiple detection elements are arranged in a straight line,
a photodetecting element for detecting the reading light of the track of the optical card; a scanning means for electrically scanning the photodetecting element multiple times per track to obtain an output signal; and an output of the photodetecting element. Based on this, an optical card reading device is provided with a specific scan detection means for detecting a specific scan of the track of the photodetection element, and a switch whose connection state is switched based on the output of the specific scan detection means; A high-speed drive circuit and a constant-speed drive circuit are provided, respectively connected to a pair of fixed contacts of the switch, and the motor is connected to a movable contact of the switch, and at least the During a specific scan period, the output of the constant speed drive circuit is supplied to the motor, and during multiple scan periods excluding the specific scan period, the output of the high speed drive circuit is supplied to the motor. An optical card reading device characterized in that the optical card reading device is provided as follows.