JPH0315227B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a card reading device that reads information from a card on which information is recorded with a code corresponding to the reflectance of light.

[Technical background of the invention and its problems]

In recent years, an optical recording card as shown in FIG. 2 has been proposed as a mass information recording medium. The format of this optical recording card 11 is that the recording area 12 is provided with reference lines 13, 13, . . . for tracking, and the two reference lines 1
Recording point arrays 14, 14, . . . are formed between the recording points 3 and 13. When reading out the recorded information, a line sensor 15 such as a CCD is used.
corresponds to an area spanning the two reference lines 13, 13, and is scanned along the reference lines 13, 13 to read the data.

FIG. 3 schematically shows a reading device for the optical recording card 11. As shown in FIG. In the figure, 16 is a light source, and the light emitted from this light source 16 is focused by a condensing lens 17 and irradiated onto the information recording surface of the optical recording card 11. The reflected light from the surface of the optical recording card 11 is transmitted to the CCD via a magnifying lens 18.
The light is received by 19. And the above CCD19
Obtain the photoelectric conversion signal PE from . Here, the size of the recording dots formed on the optical recording card 11 is generally as follows:
It is smaller than 1 bit of CCD19, and for one recording point, so that stable reading can be performed.
Approximately 3 bits of CCD19 are supported. Therefore, the recording points on the optical recording card 11 are read by sampling the photoelectric conversion signal PE outputted from the CCD 19 at an appropriate period.

Next, by relatively moving the position of the optical recording card 11 and the optical system 20 comprising the light source 16, lenses 17, 18, CCD 19, etc. in the direction of arrow A, information is sequentially recorded along the reference lines 13, 13, . read After this reading is completed, the card 11 and the optical system 20 are moved relative to each other in the direction of arrow B, and then moved relative to each other again in the direction of arrow A, thereby reading the information recorded between the adjacent reference lines 13 and 13. .

By the way, in the above configuration, CCD19
When sampling the photoelectric conversion signal PE output from the optical recording card 11, the sampling period is determined by how many bits the CCD 19 corresponds to one recording point on the optical recording card 11 ) will depend on the magnification. For this reason, it is necessary to precisely match the magnification of the enlarging optical system. However, precisely adjusting the magnification of the enlarging optical system in this way takes time and effort, which poses a problem during mass production or readjustment.

[Purpose of the invention]

This invention was made in view of the above circumstances,
The purpose is to provide a card reading device that can read data stably without strictly adjusting the magnification of the optical system, and that can simplify adjustments during manufacturing and readjustment.

[Summary of the invention]

The present invention provides a plurality of reference lines provided on a card having an optical recording surface, and a recording dot array provided between the plurality of reference lines in a direction perpendicular to the reference lines and existing in a plurality of rows along the reference lines. irradiation means for irradiating the optical recording surface of the card, and guiding light from the optical recording surface of the card to a sensor that is made up of a plurality of bits and that reads each recording point sequence while moving along the reference line; In a card having an optical system such that one recording point on the card corresponds to a plurality of bits of this sensor, the reference line is detected by the photoelectric conversion signal from the sensor, and the detected two reference lines are , and selects a sampling pattern corresponding to the interval between the reference lines to be measured from a memory in which multiple types of sampling patterns corresponding to the interval between the reference lines are stored. The output of the sensor is sampled based on the sampling pulse.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIG. Optical system 20 shown in FIG. 3 above
The photoelectric conversion signal PE obtained by is supplied to a reference line detection circuit 21 and a sampling circuit 22. The reference line detection circuit 21 has a photoelectric conversion signal
Reference line 1 provided from PE to optical recording card 11
3, 13,... is a circuit that detects 1 of CCD19.
The reference portion at the beginning of data and the reference line portion at the end of data in the scan are detected. The detection signal obtained from this reference line detection circuit 21 is supplied to a reference line interval measurement circuit 23 and a memory 24.
The reference line interval measuring circuit 23 is composed of, for example, a counter circuit, and calculates the reference line interval on the optical recording card 11 by integrating the number of clocks between two reference line detection signals detected by one scan of the CCD 19. It is calculated how many bits the interval between 13 and 13 corresponds to on the CCD 19. In addition, the memory 2
Reference numeral 4 stores sampling patterns corresponding to several types of reference line intervals, and a sampling pattern is selected by a signal from the reference line interval measuring circuit 23. When the reference line interval signal at the beginning of data is received from the reference line detection circuit 21, the selected sampling pulse is output. This sampling pulse is supplied to the sampling circuit 22, and the photoelectric conversion signal PE from the optical system 20 is sampled based on this sampling pulse. Then, the information recorded on the optical recording card 11 is output from the sampling circuit 22 as a read signal OP.

Next, the signal flow will be explained. CCD1
9 starts scanning the optical recording card 11,
The photoelectric conversion signal PE is sent to the reference line detection circuit 21. When the reference line detection circuit 21 detects the reference line portion at the beginning of the data, the counter in the reference line interval measuring circuit 23 starts counting the reference clock, and integrates the reference line interval for measuring the reference line interval. begins. The CCD 19 continues to be scanned, and when the reference line detection circuit 21 detects the reference line portion at the end of the data, the counter of the reference line interval measurement circuit 23 is stopped, and the integration for interval measurement is started. finish. The integrated value is sent to the memory 24, and a stored sampling pattern is selected based on this integrated value (reference line interval). The above-described operations are performed until one scan of the CCD 19 is completed. Next CCD1
9 scan is started, and when the reference line detection circuit 21 detects the reference line portion at the beginning of the data, the sampling pulse selected in the previous scan is output from the memory 24, and the sampling pulse selected in the current scan is outputted by the sampling circuit 22. The photoelectric conversion signal PE thus obtained is sampled to obtain a read signal OP.

In this way, the interval between the reference lines measured in one scan of the CCD 19 is not made to correspond to this scan, but is made to correspond to the next scan in the sampling operation. Originally,
The interval between the reference lines measured in one scan by the CCD 19 is different from the interval between the reference lines in the next scan, but normally, one scan by the CCD 19 is fast, and this one scan is different from the interval in the next scan. This is sufficiently effective because it is impossible for the magnification of the magnifying lens 18 to suddenly change within a short period of time.

According to this configuration, sampling is performed using a sampling pulse that corresponds to the magnification of the enlarging optical system, so even if the magnification of the enlarging optical system that enlarges the recording point of the optical recording card slightly deviates from the specified value, the sampling is stable. accurate readings are possible, and precise adjustments are not required.

〔Effect of the invention〕

As explained above, according to the present invention, it is possible to provide a card reading device that can read data stably without strictly adjusting the magnification of the optical system, and that can simplify adjustments during manufacturing and readjustment. .

[Brief explanation of the drawing]

FIG. 1 is a block diagram for explaining an optical recording medium reading device according to an embodiment of the present invention.
FIG. 2 is a diagram for explaining an optical recording card, and FIG. 3 is a schematic diagram of an optical recording medium reading apparatus according to a conventional apparatus and an embodiment of the present invention. 11... Optical recording card (card), 12... Recording area, 13, 13... Reference line, 14, 14...
Recording point sequence, 16... light source, 17... condensing lens,
18...Magnifying lens, 19...CCD (sensor),
20...Optical system, 21...Reference line detection circuit, 22
... Sampling circuit, 23 ... Reference line interval measurement circuit, 24 ... Memory, PE ... Photoelectric conversion signal,
OP...read signal.

Claims (1)

[Scope of Claims] 1. A plurality of reference lines provided on a card having an optical recording surface, and a record provided between the plurality of reference lines in a direction perpendicular to the reference lines and existing in a plurality of rows along the reference lines. irradiation means for illuminating the optical recording surface of the card having a dot array; and a sensor comprising a plurality of bits that emits light from the optical recording surface of the card and reading each recording dot array while moving along the reference line. a reference line detection means for detecting the reference line using a photoelectric conversion signal from the sensor; , a reference line interval measuring means for measuring the interval between two reference lines detected by the reference line detection means; a memory storing a plurality of types of sampling patterns corresponding to the intervals between the reference lines; a selection means for selecting from the memory a sampling pattern corresponding to the interval between the reference lines measured by the reference line interval measuring means; and an output of the sensor based on the sampling pulse of the sampling pattern selected by the selection means. A card reading device comprising: sampling means for sampling; 2. The sampling pattern as set forth in claim 1, wherein the sampling pattern from the selection means used in the sampling means is obtained in accordance with the content of measurement between the reference lines before one reading scan of the sensor. Card reader.