JPS61168130A - Reader for optical card - Google Patents

Abstract

PURPOSE:To improve contrast and to make a correct and stable read by scanning each track by a photodetecting element plural times, and detecting the photodetecting element reading a track mark and extracting a signal read out in one scanning period where the read level exceeds a specific level. CONSTITUTION:Information is recorded on plural parallel tracks T on an optical card and a mark M is formed at end parts of the tracks T. The photodetecting element 20A scans each track plural times and outputs read signals of marks M and tracks T. A track mark detecting circuit 41 is supplied with a playback data signal from a data reproducing circuit 37 and also supplied with a clock signal from a PLL36. The output of the circuit 41 is supplied to a pulse generating circuit 43 through a one-scanning-period delay circuit 42. A gate 39 is opened only for one scanning period following a scan in which a track mark is detected by the circuit 41 and accurate data reproduced by the circuit 37 from a high- contrast readout signal is supplied to a data processing circuit 38, which performs accurate processing.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to each 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. The present invention relates to an optical card reading device that optically reads information signals from a track.

[Conventional technology]

As a so-called memory card or software card, as shown in FIG. As shown in FIG. 5, the information signal is recorded optically by means of an optical recording trace, for example an arrangement of pins I-P.

An optical card reading device for reading information signals recorded in each trunk l'' from such a card (1) is used, as shown in FIGS. 6 and 7. The feed roller (2) sends the card (11) in the direction of the arrow (3) along the reference end surface (la), and the light (5) from the illumination light source (4) such as a light emitting diode is sent to the condenser lens ( 6), the reflected light from the track T, that is, the reading light (7) of the I/rack T, passes through the imaging lens (8) to the holding plate (9). The photodetecting element a0 is projected onto the photodetecting element 0 [held at
) are arranged in a straight line, and the images projected thereon are read by electrical scanning.As shown in FIG. 8, the longitudinal direction of the image of the track is aligned with the detection element ( The images P' of all the bits of one track are simultaneously formed on the element (101) in alignment with the arrangement direction of 10a), so that the information signals for one trunk are read at once.

Further, as an optical card, an optically readable mark (track mark) M is formed at a position corresponding to each trunk T, and this mark M can be used to know the address of the track to be read. There is one that allows you to select the idle track and read it.

FIG. 9 shows an example of such an optical card, in which a plurality of trunks T are formed in a rectangular card (11) that are perpendicular to the reference end direction (lla) and parallel to each other. The information signal was recorded so as to be optically readable by the focus arrangement as described above, and a linear mark M parallel to track 1 was formed at a position on the upper extension of each track T. It is something.

This mark M is made optically readable. For example, the in-focus part of track T has “ζ” compared to other parts.
When the reflectance of light is made low, the mark M is also considered to be a part of low reflectance, and conversely, when the reflectance of light is reduced to 11 in the bit part of track '1゛ compared to other parts, the mark M is also considered to be the +O+ part of the reflectance.

Figure 10 shows an example of a photodetecting element of a reading device that can be used for optical cards such as those described in ``1''. 1-
It consists of a photodetecting element (21) to read the rack 'F' and a photodetecting element (22) arranged on the upper end side thereof, and the photodetecting element (21) has a plurality of detecting elements (21a) arranged in a straight line. The photodetecting element (22) is similar to the above-mentioned photodetecting element α, and has a plurality of detecting elements (22a) arranged in a straight line. However, each element (22) is configured such that the sum of the outputs of a plurality of detection elements (22a) is taken out as the output of the element (22).

Although the light from the reading device h+ and the thread are not small, the light from the illumination light source is not equal to the length of the track 1 of the car (ii) in FIG. It enters the card (11) for a few minutes and marks M in Fig. 9.
The reading light of the track T is projected onto the photodetecting element (22) J-, and the integrated light of the track T is projected onto the photodetecting element (21).
) so that it is projected on top.

The electrical configuration of a conventional optical card reading device is, for example, as shown in FIG. Transfer elements (21r) and (22r) and transfer elements (21t) and (221), which correspond one-to-one, are respectively arranged with a gate g in between.

First, the gate g is closed for a certain period (accumulation period), and 'l!' is generated by light. i m is accumulated in each light receiving element (21r) and (22r). Next, gate 1-g is opened momentarily, and the accumulated charges are transferred in parallel to the corresponding transfer elements (21t) and (22t), and the light-receiving elements (21r) and (22r) are transferred in parallel. Charge accumulation starts again. Each transfer element (21t) and (22
The charges transferred to t) are scanned by a scanning signal (read clock) from the scanning circuit (31), and are scanned for a certain period of time (
during the scanning period) as a serial signal.

Note that the stacking period and the scanning period are the same time and timing, so the term scanning period (scanning) will be used in the following explanation.

The readout signal that is the output of the photodetection element (21) is a discrete analog signal of the order of magnitude of the detection element (21a), and is amplified to a predetermined level by the amplifier (32) and then sampled and held. The signal passes through a circuit (33) and a low-pass filter (34), is converted into a continuous analog signal, and is supplied to a comparator (35). comparator(
35) Human power (rV number) is binarized by comparing whether the electrification is higher than or lower than the voltage in base 4, and the binarized readout signal is used as P L L (36) and data reproduction same 1 The clock signal is extracted and reproduced in PLL (36), and this clock signal is supplied to the data font circuit (37) to reproduce binary data. The binary data is supplied to the data processing circuit (38) via the gate (39), and P L L
(36) is processed as appropriate using the clock signal from (36).

The track mark detection signal, which is the output of the trunk mark photodetection element (22), is sent to the cable 1 via an amplifier (23).
(39), which is opened and transferred to the data processing circuit (38) only if the data reproduced by the data reproduction circuit (37) is a track information signal.

[Problem that the invention seeks to solve]

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

Here, as shown in FIG. 12, three pits Ps, P2 . Regarding P3, the amount of light incident on a specific photodetecting element corresponding to pits Pt to P3 changes periodically as shown in FIG. 13 in accordance with the feeding of the card. That is, the amount of incident light is the same as that of pit P1. P2
and time tcm at which the center of the projected image of P3 coincides with the center of the photodetection element.

At tC2 and tc3, the point in time when the middle part of each focus is projected onto the light detection element, in other words, the time point tc+ and tc2, the intermediate time point t1111, and the time point tc2.
The minimum value is reached at an intermediate time point tT112 between and tC3.

However, the scanning period of the track to which pit P2 belongs is
Between the time point tc2 when the photodetection output is at its maximum and the time tmi at which the photodetection output is at its minimum until LIf12, the readout signal obtained from the photodetection element has the following:
There is a problem in that an invalid component is included due to the projected image of the intermediate portion with the adjacent trunk, and the contrast of the pit-corresponding signal due to the in-focus projected image is deteriorated. Also, due to some reason, the timing of the scan is shifted °ζ, and the scan period is ta1 to t.
Even when G2 or tc2 to te3, the output of the track mark detection element (22) is the same as when the scanning timing is normal, so G1-(39
) becomes open and the information recorded on two tracks is read out at the same time, which is equivalent to a state in which the two tracks overlap, making it impossible to read out recorded information. was there.

In view of the above, it is an object of the present invention to improve the contrast of bit-corresponding signals and to improve correct recording. ” An object of the present invention is to provide an optical card reading device that can stably read recorded information.

[Means for solving problems]

In the present invention, an information signal is recorded in a plurality of parallel tracks T so as to be optically readable by an array of optical recording traces P, and an optically readable mark M is formed at the end of the track T. optical card (
11), a plurality of detection elements are arranged in a straight line,
A photodetector element (20^) detects the reading light of the mark M on the optical card (11) with a detection element (22a) at the end, and this photodetector element (20^) is electrically scanned to generate an output signal. Based on the output of the scanning means (31) and the detection element (22a) at the end of the photodetection element, the photodetection element (20^)
In an optical card reading device having an extraction means (39) for extracting an output signal of or a signal based thereon, the scanning means (31) is arranged such that the scanning hand 1ffi (31) scans each track T a plurality of times. mark detection means (4J) for setting the scanning period of and detecting the output signal of the end detection element (22a) in the output signal of the photodetection element (20^); a delay means (42) for delaying the output signal by at least one scanning period of the scanning means (31) up to the scanning period immediately before the plurality of scans scans the trailing edge of the mark M; This is an optical card reading device provided with an extraction control means (43) for controlling the extraction means (39) to operate only for one scanning period of the scanning means (31) based on the output of the scanner (31).

[Effect]

According to the present invention, the information signal recorded on the track is read during the scanning period in which the mark detection means (41) detects the center portion of the track mark.

〔Example〕

Hereinafter, one embodiment of the optical car 1' (7) reading device according to the present invention will be described with reference to FIGS. 1 to 3.

The structure of one embodiment of the present invention is shown in FIG. In FIG. 1, portions corresponding to ζ and FIG. 11 are designated by the same reference numerals, and redundant explanation will be omitted.

In FIG. 1, (20A) is a photodetecting element,
It is configured such that the aforementioned photodetecting elements (21) and (22) are connected together, and signals obtained by reading marks M and tracks T are output in series. (4■) is a track mark detection circuit including a counter, and this mark detection circuit (41) is supplied with a reproduced data signal from a data reproduction circuit (37) and a clock signal from a PLL (36). Supplied.

The output of the mark detection circuit (41) is delayed by one scanning period II
It is supplied to the pulse generation circuit (43) via (42). In the case of FIG. 2, the delay amount of the delay circuit (42) may be two or three scanning periods. The output pulse of the pulse generation circuit (43) is sent to the data reproduction circuit (37) and the data processing circuit 1?
! (38) and the gate (39) interposed between the two.

The operation of this embodiment is as follows. In this example, since recent photodetecting elements and optical systems have been improved and their resolution has improved, here, one photodetecting element corresponds to several scratches per pit in the photodetecting element. Shime ζ is there. The length of the scanning period by the scanning circuit (31) and the cart feeding speed by the roller (2) are determined so that one track is scanned several times according to this resolution. As a result, 1 11 AI pitches in each scanning period)
The relative position of P2 and the corresponding photodetecting element S of 1 11&l moves as shown in FIG. Then, the output of the photodetecting element S is the pit P2.
As shown in FIG. 3A, it is lowest at So, highest at S4, and at S2 and S6 where the edge of the pit crosses the center of the photodetecting element. This is the average value. The same applies to other tracks.

On the other hand, the relationship between the track mark and the photodetection element is the same as described above, and the edge of the mark crosses the photodetection element.
Marks are detected in the scans from 2 to S6.

That is, in S2, when the front edge of the trunk mark (sigh) is read by the photodetection element (2OA), the mark detection circuit (37) outputs the mark reproduction data of a predetermined bit length III from the data reproduction circuit (37). The counter of the mark detection circuit (41) counts the bit length m of this mark reproduction data using the clock from the PLL (36), and detects that it is predetermined mark reproduction data. Then, the output of the mark detection circuit (41) becomes "old". Therefore, the output signal of the mark detection circuit (41) becomes "old".
As shown in Fig. 3B, the mark becomes "Old" during the scanning period in which the trunk mark is detected, and becomes "Lo" during the scanning period in which the trunk mark is not detected.
As shown in FIG. 3C, the output signal of the mark detection circuit (41) is delayed by one scanning period by the one-scanning period delay circuit II (42), and is sent to the pulse generating circuit (43) as a trigger. ) is supplied to the pulse generation circuit (43).
supplies a gate pulse (39) with a pulse width equal to one scanning period as shown in the third diagram. Therefore, game 1- (39) is applied only for one scan period (corresponding to °ζS3 in FIG. 2) following the scan in which the mark detection circuit (41) detects the track mark (corresponding to 82 in FIG. 2). As is clear from Figure 3A,
M: Data reproduction times from readout signal with high contrast V
Accurate data stably reproduced by the i+ (37) is transferred to the data processing circuit (38), where reliable data processing is performed.

Furthermore, as is clear from FIG. 2 and FIG.
If it is in the range of , a readout signal with a quotient contrast can be obtained in the same way as the child series, so the continuous line time of the delay circuit (42) may be two or three scanning periods.

Furthermore, in this embodiment, scanning is performed multiple times per trunk, so even if the timing of scanning is shifted, the information on two tracks will not be read out simultaneously, unlike in the conventional case.

It should be noted that the present invention is not limited to the above-described embodiments, and those skilled in the art will easily understand that various modifications can be made, such as using an m-bit shift register and a digital comparator as the mark detection circuit. It's around the corner.

(Effects of the Invention) Since the sensor is scanned multiple times per track, the photodetecting element detects that the track mark has been read, and the signal read out during one scanning period exceeding a predetermined level is used. In addition to improving the contrast of pit-compatible signals,
Two adjacent tracks are not read at the same time,
Correct recorded information can be read stably.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of an optical card reading device according to the present invention, FIGS. 2 and 3 are line diagrams and time charts for explaining the same, and FIGS. A plan view of an example and an enlarged view of its main parts, No. 6
7 and 7 are side and perspective views of an example of the configuration of an optical cart reading device, FIG. 8 is a diagram for explaining the reading state of the 1-rack, and FIG. 9 is a diagram for explaining the present invention. FIG. 10 is a plan view showing the optical card 11 to be removed
FIG. 11 is a block diagram showing an example of the electrical configuration of a conventional optical card reading device, and FIGS. 12 and 13 are diagrams for explaining the conventional device. (11, (11) is light'? card, QOI, (2
0), (20A). (21), (22) are photodetecting elements, (31) is a scanning means, (39) is a gate, (41) is a comparator,
(42) is one scanning period i! ! (43) is a pulse generation circuit for one scanning period, T is a trunk, and M is a trunk mark. 11 Kaisho 6l-168130 (6) <Piroko OQ

Claims (1)

[Claims] An optical card is used in which information signals are optically readably recorded on a plurality of parallel tracks by an array of optical recording traces, and optically readable marks are formed at the ends of the tracks. , a photodetection element in which a plurality of detection elements are arranged in a linear manner, and a detection element at an end detects the reading light of the mark on the optical card; and an output signal is obtained by electrically scanning the photodetection element. In an optical card reading device comprising a scanning means and an extraction means for extracting an output signal of the photodetecting element or a signal based thereon based on an output of the detection element at the end of the photodetecting element, the scanning means a mark detection means for setting a scanning period of the scanning means so that the mark scans each track a plurality of times, and detecting an output signal of the detection element at the end of the output signal of the photodetection element; , a delay means for delaying the output signal of the mark detection means by at least one scanning period of the scanning means, up to a scanning period immediately before the trailing edge of the mark is scanned in the plurality of scans; and extraction control means for controlling the extraction means to operate for only one scanning period of the scanning means based on the output of the optical card reading apparatus.