JP2730133B2 - Optical card processing equipment - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an optical card processing apparatus for performing recording or reproduction processing on an optical card.

(Prior Art) FIG. 3 is a configuration diagram showing a general configuration of an optical head incorporated in an optical card processing device.

In the drawing, reference numeral 1 denotes an optical card on which information to be read is recorded, 2 denotes a semiconductor laser as a light source that emits light to the optical card 1 side, and 3 denotes light reflected from the optical card 1 and corresponds to the amount of received light. An optical detector 4 composed of various light receiving elements for outputting an electric signal generated by the semiconductor laser 2 guides the light emitted from the semiconductor laser 2 to the optical card 1, while the optical detector 4 guides the reflected light from the optical card 1 to the photodetector 3. System.

The optical system 4 includes a collimator lens 41, a polarizing beam splitter 42, an objective lens 43, and a condenser lens 44.

In the above configuration, emitted light h ₁ emitted from the semiconductor laser 2 reaches the objective lens 43 through a collimator lens 41 and the polarization beam splitter 42 is irradiated is focused by the objective lens 43 to the optical card 1 . Thereafter, it reflected light h ₂ from the optical card 1 is diffracted by the polarizing beam splitter 42 through the objective lens 43 contrary to the above, the condensing lens 44
And is incident on the photodetector 3. The photodetector 3 includes a recording / reproducing light receiving element, a focus controlling light receiving element, and a tracking controlling light receiving element.
Each light receiving element is configured to output an electric signal corresponding to the amount of received light.

FIG. 4 shows the structure of the optical card 1. An information recording section 80 is provided on one side of one surface, and the information recording section 80 is divided into a plurality of track guides 81 positioned in parallel.
The information pits 83 are arranged in the pits. And
The optical card 1 is relatively moved with respect to the optical head described above, whereby the irradiation light emitted from the optical head scans the information pits 83 of the track 82.

FIG. 5 is a diagram for explaining the amount of light detected by the recording / reproducing light receiving element 10 of the photodetector 3 corresponding to the scanning state of the irradiation light spot S ₁ (corresponding to the detection light spot S ₂ ) on the optical card 1. irradiation light spot S ₁ by the optical card 1 is moved in the arrow direction is relatively moved to the position of b from the position of a.
And along with the movement, when the amount of reflected light at the position X where information pits 83 exists becomes minimum is detected minimum light k ₁ from the detected light spot S ₂ corresponding to the irradiation light spot S _1, contrast It reflected light amount at a position Y where the information pits 83 are not present so that the maximum light amount k ₂ is detected when the maximum. A reproduction signal is formed based on the detected light amount.

(Problems to be Solved by the Invention) However, in the above configuration, there is a problem that a detected light amount cannot be accurately obtained in accordance with the presence or absence of the information pit 83, and a reproduction signal of correct information cannot be formed.

That is, for example, when the irradiation light spot S ₁ is located just intermediate position Z of the information pits 83, it takes the respective information pits 83 on both sides of the irradiation light spot S ₁ is located on both sides, the result, the light amount k ₁ and light quantity k ₂ intermediate, in which the amount of light k ₃ that interfere during reproduction signal formed thereby is detected.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and has as its object to enable a detected light amount to be accurately obtained in accordance with the presence or absence of an information pit and to form a reproduction signal of correct information.

(Means for Solving the Problems) In order to achieve such an object, the present invention irradiates an optical card in which a plurality of information pits are arranged and formed at intervals corresponding to information recording along a track direction. Means for scanning the information pits in the direction while irradiating the light spot, and reflecting the irradiation light spot from the optical card to form a detection light spot having a size corresponding to the irradiation light spot on the light receiving surface of the light receiving element. Means for reproducing the scanned information pits using a detection output of a light receiving element with respect to a detected light spot, wherein the plurality of information pits scanned in the track direction are adjacent to each other. It is used for an optical card that includes information pits whose arrangement interval is equal to or smaller than the spot width of the irradiation light spot in the direction, and the detection width in the track direction is , And a light receiving element which is smaller than the minimum arrangement interval of the information pits in that direction.

(Operation) According to the structure of the invention of claim (1), the irradiation light spot is located in the middle of the information pits and covers the information pits on both sides, and the corresponding detection light spot is formed on the light receiving element. Also, since the detection width of the recording / reproducing light receiving element is a width corresponding to a width equal to or less than the minimum arrangement interval of the information pits in the detection light spot, the amount of light without the information pits without being affected by the information pits on both sides. Detection is performed.

According to the invention of claims (2) and (3), the reproducing method of the optical card recording of claim (1) is performed.

(Example) Hereinafter, an example of the present invention will be described in detail with reference to the drawings. The optical card processing apparatus according to the present invention is constructed by integrating various signal processing circuits and the like with the optical head shown in FIG. 3, and its basic configuration is generally known from the prior art. Description is omitted.

1 (A) and 1 (B) are front views showing respective detection surfaces of a recording / reproducing light receiving element 20 which is a feature of the present invention.
In those shown in (A) is, by using a narrow as a recording reproducing light-receiving element 20 itself, less than the width of the detection light spot S _2, that is, the detection width obtainable with the recording and reproducing light receiving element 20 in the detection light spot S _2,
The width W corresponds to a width equal to or less than the minimum arrangement interval of the information pits in the track of the optical card.

In the case shown in (B), the recording / reproducing light receiving element 20 is used.
Is used conventionally, and the detection width is set to W by providing each of the masking 21 on both sides of the detection surface.
With the configuration using 21, a commercially available light receiving element can be used.

Next, the light-receiving operation of the recording / reproducing light-receiving element 20 shown in FIG. 1A will be described with reference to FIG.

In the position X in the irradiation spot S ₁ in a position where the center of the irradiation light spot S ₁ is aligned with the center of the information pit 23,
Since the reflected light amount becomes minimum is detected minimum light k ₁ in the detection light Supoto S ₂ by the recording and reproducing light receiving element 20, in the position Y is not at all exist of the irradiation light spot S ₁ is information pit 23 contrast, the reflection the amount of light is maximum light k ₂ is detected by the recording and reproducing light receiving element 20 becomes maximum.

In contrast, the center of the irradiation light spot S ₁ is, if the irradiation light spot S ₁ at a position Z that matches the middle position between the information pits 23 which is closest is located, both sides of the irradiation light spot S ₁ is information according to the pit 23 but, because the detection width W of the recording and reproducing light receiving element 20 is set as described above, the site that is actually detected in the detection spot S ₂ is the information pit 23
Only the respective intermediate positions are provided, and therefore, the detected light amount is k ₂ as in the case of the Y position.

In this way, the amount of detected light can be accurately obtained in accordance with the presence or absence of the information pits 23.

In the embodiment shown in FIG. 1B, the same detection operation as described above is performed.

(Effects of the Invention) Therefore, according to the present invention, among a plurality of information pits scanned in the track direction, information pits whose adjacent arrangement intervals are equal to or smaller than the spot width of the irradiation light spot in the direction are included. Is used for an optical card that has a light receiving element whose detection width in the track direction is smaller than the minimum arrangement interval of information pits in that direction. Even when an irradiation light spot is formed, the detection of the light quantity without the information pits is performed without being affected by the information pits on both sides, so that the detected light quantity can be accurately obtained according to the presence or absence of the information pits. As a result, a reproduction signal of correct information can be obtained.

[Brief description of the drawings]

1 and 2 relate to an embodiment of the present invention. FIGS. 1 (A) and 1 (B) are front views of different embodiments of a recording / reproducing light receiving element, and FIG. FIG. 4 is an explanatory diagram illustrating a detected light amount of a recording / reproducing light receiving element of a photodetector corresponding to a scanning state of an irradiation light spot (corresponding to a detection light spot) on a card. FIG. 3 is a configuration diagram showing a general configuration of an optical head, and FIG.
FIG. 1 is a configuration diagram showing a general configuration of an optical card. FIG. 5 is a diagram corresponding to FIG. 2 in a conventional example. 20: Light receiving element for recording / reproducing, 21: Masking, 23: Information pit, S _1: Irradiation light spot, S _2: Detection light spot.

Claims (1)

(57) [Claims] A means for scanning an information pit along said track direction while irradiating an irradiation light spot onto an optical card having a plurality of information pits arranged at intervals corresponding to information recording along said track direction; Means for reflecting an irradiation light spot from the optical card to form a detection light spot of a size corresponding thereto on the light receiving surface of the light receiving element, and using a detection output of the light receiving element for the detection light spot. In the optical card processing apparatus for reproducing the scanned information pits, among the plurality of information pits scanned in the track direction, information pits whose adjacent arrangement intervals are equal to or smaller than the spot width of the irradiation light spot in the direction are included. A light receiving element that is used for the included optical card and whose detection width in the track direction is equal to or less than the minimum arrangement interval of information pits in that direction. An optical card processing device, comprising: