JP2684684B2 - Optical card - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Field of Industrial Application> The present invention relates to an optical card having an optically readable data recording section.

<Prior Art> An optical card has recently been actively studied as an optical recording medium capable of optically reading data. In the external view of the optical card schematically shown in FIG. 7, the optical recording portion generally comprises a plurality of line-shaped data tracks (T) formed in parallel with the short side direction of the card. A dot-shaped (or pit-shaped) pattern corresponding to digital information is recorded on this data track.

As a method of reproducing information recorded on such an optical card, a line sensor such as a CCD is installed so as to be parallel to the data track, and while maintaining this parallel state, the line sensor and the optical card are relatively moved. It has been proposed to read the recorded data by moving it.

Normally, the line sensor is installed so that its scanning direction is orthogonal to the relative movement direction of the card, and if it is a normal card, the data track is formed in a state orthogonal to the relative direction. Therefore, the scanning direction of the line sensor is parallel to the data track, and the data can be read.

However, at the time of recording data on an optical card (at the time of manufacturing a card for a read-only card), a data track may be formed to be slightly inclined with respect to the moving direction of the card. In this case, the scanning direction of the line sensor and the data track are not parallel to each other, which makes it impossible to read data accurately. In order to solve such a problem, for example, in Japanese Utility Model Laid-Open No. 62-147126, a plurality of guide lines are provided in front of the head data track in parallel with the data track, and this mark is detected before reading the data. There is disclosed an optical card that rotates and corrects the line sensor so that the track and the line sensor are parallel to each other.

<Problems to be Solved by the Invention> However, in the above-mentioned optical card, since the data track and the guide line are parallel to each other, the guide line as shown by line sensors (S ′) and (S ″) in FIG. When inclinations in different directions with respect to (GL) occur, the output waveform (W) of the line sensor in FIG. 6 (b) is irrelevant to the inclination direction, and the guideline was read by the line sensor in the inclination direction. It was difficult to know from the information, and the rotation correction for correcting the line sensor parallel to the guideline was not performed quickly in some cases.

Further, in order to obtain the information on the inclination, it is necessary that at least one guideline image is formed on the line sensor. For this purpose, the guideline width must be narrower than the data bit width. However, it is difficult to make a card, and a high-resolution reader is required.

Therefore, the present invention has been made to solve the above problems. In an optical card for reading recorded data by using a line sensor, a parallel state with a quick rotation correction is performed against the inclination of the line sensor with respect to the data track. It is an object of the present invention to provide an optical card capable of accurately maintaining the read data and eliminating read errors of recorded data.

<Means for Solving the Problems> The present invention, which has been made to solve the above problems, provides an optical card in which a guideline is provided in front of an optical recording section including a plurality of line-shaped data tracks that are parallel to each other. It is tilted by a small angle with respect to the direction parallel to the data track.

<Operation> As described above, in the optical card of the present invention, the guideline is inclined at a slight angle with respect to the data track, and the guideline is determined in advance by the inclination of the guideline when the data track and the line sensor are in a parallel state. By comparing the length with the guideline reading length actually read from the line sensor, the tilt direction of the data track can be reliably detected. Further, the line sensor is less likely to be applied to the edge portion of the guide line due to the inclination correction processing of the line sensor, and the width of the guide line does not need to be narrower than the width of the data bit.

<Example> Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a partially enlarged view of a head portion of an optical recording section of an optical card according to the present invention.

Line data tracks (T1), (T2), etc., where the digital data of characters or images, for example, are used to record a signal with a difference in reflectance, a portion with a high reflectance (non-dot portion) Is recorded corresponding to a portion (dot portion) having a small reflectance.

All these data tracks are formed in parallel, and in this embodiment, adjacent data tracks are formed in contact with each other. A format may be adopted in which a gap is provided between each data track so that adjacent data tracks do not contact each other.

One guideline (GL1) inclined by θ with respect to the data track is provided in front of the first data track (T1). It is desirable that the tilt angle (θ) be about the minimum value that allows the width of the guideline to be imaged on the line sensor when the tilt between the data track and the line sensor is maximized due to variations in card production. Length of guideline (GL1) (l
In 3), the guideline (GL1) may have a length corresponding to the length of the data track, and its width (l1) may be about the width of the data track. When the guideline width is 10 μm, θ is about 1 degree.

Further, FIG. 4 shows the second embodiment, and a plurality of guide lines (GL2) inclined by θ with respect to the data track are provided in parallel in front of the leading data track (T1). It is desirable that the inclination angle (θ) be about the minimum value that allows the width of the guideline to be imaged on the line sensor when the inclination between the data track and the line lancer is maximized due to variations in card production. The length (l3) of the guideline (GL2) may be such that the guideline (GL2) corresponds to the length of the data track, and its width (l1) may be about the width of the data track. When the guideline width is 10 μm, θ is about 1 degree.

If there is only one guideline when the rotation angle of the line sensor for making the scanning directions of the data track and line sensor parallel, the guideline may be out of the line sensor's field of view. By providing this, the inclination of the line sensor with respect to the data track can be adjusted more accurately without the guideline being out of the visual field of the line sensor.

FIG. 2 shows the optical system of the reading device. Light sources (12)
The irradiation light emitted from (red LED) is a half mirror (1
The recording section of the card (c) is irradiated via the (4), and the reflected light from the card (c) is reflected by the half mirror (14) and the lens (1
It is configured to pass through 3) and form an image on the line sensor.

The line sensor (11) has elements arranged in a direction orthogonal to the paper surface and scans the optical recording section of the card in this direction, and the card (c) is sent in the direction of arrow Y, whereby the card is sent. The optical recording unit can be scanned.
As described above, the optical system and the card can be rotated by a slight angle, that is, the inclination of the line sensor in the scanning direction can be corrected with respect to the data track of the card.

Next, a description will be given of a tilt angle correction method in the case where the scanning direction of the data track and the line sensor are tilted when the optical card of the present invention is used to read data using the above-mentioned reading device.

When the card (c) is set in the reading device in FIGS. 3 and 5, the line sensor first reads the guideline. At this time, it is assumed that the scanning line of the line sensor (S ') is parallel to the data track.

 At this time, (l2) can be calculated by the following formula.

Here, (1l) and (θ) are values that can be known at the time of data recording or card manufacturing,
The value of (l2) can be obtained in advance.

If the data track and the scan line of the line sensor (S1) are not parallel, the width (l2 ') of the guide lines (GL1 and GL2) along the scan line of the line sensor (S') is different from (l2). It will be a long length.

If the number of pixels (n) of the line sensor (S ') detecting the guideline is known, (l2') is the pixel pitch (m) of the line sensor and the magnification (v) of the optical system of the reading device. Similarly, since it is a value that can be known in advance, Can be calculated by calculating.

In the case of the present embodiment, when the value of (l2 ′) is larger than (l2), the data track is inclined to the right, and conversely, when the value of (l2 ′) is smaller than (l2), the data track is If you are leaning to the left, it will be a problem. Therefore, by rotating the rotating device in accordance with the tilt direction until (l2) and (l2 ') become equal, the line sensor and the data track can be quickly made parallel and can be kept parallel.

<Effects of the Invention> As described above, according to the present invention, in reproducing an optical card in which data is recorded on a plurality of line-shaped data tracks using a line sensor, scanning of the data track and the line sensor is performed. The directions can always be made parallel and data can be read accurately.

[Brief description of the drawings]

FIG. 1 is a partially enlarged view of a recording portion of an optical card of the present invention, FIG. 2 is an explanatory view of an optical system of a reading device, and FIG. 3 is an explanatory view of inclination correction of an optical card of the present invention. FIG. 4 is a partially enlarged view of the recording portion of the optical card of another embodiment of the present invention, FIG. 5 is an explanatory view of the inclination correction of the optical card in FIG. 4, and FIG. And FIG. 7 is an external view of the optical card. (11) …… Line sensor, (12) …… Light source (13) …… Lens, (14) …… Half mirror (c) …… Optical card, (GL), (GL1), (GL2) …… Guideline (S), (S ') ... scan line of line sensor (X) ... sub-scan direction of line sensor (Y) ... card moving direction (T), (T1), (T2) ... data track

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-62-143239 (JP, A) SAI-KAI 62-147126 (JP, U)

Claims (1)

(57) [Claims] 1. An optical card in which a guideline is provided in front of an optical recording section composed of a plurality of line-shaped data tracks which are parallel to each other, wherein the guideline is tilted by a slight angle with respect to a direction parallel to the data track. And optical card.