JP2523166Y2 - Optical disk drive - Google Patents

Description

[Detailed description of the invention] (a) Industrial application field The invention is applicable to various optical disks, that is, CDs, laser disks, and CDs.
The present invention relates to an optical disk device that enables a ROM, a write-once optical disk, and a rewritable optical disk to be used in the same optical disk device.

(B) Conventional technology According to the standards of CD, CD-ROM, and rewritable optical disks, information in the disk is recorded in the inner lead-in portion as shown in FIG. After loading the optical disc, it is necessary to reproduce the lead-in section.
The lead-in part is in a certain fixed range (Maxφ46mm ~ φ50m
m), the pickup that reproduces the signal generally uses φ48 at the center of the lead-in to ensure signal reproduction.
The mechanism does not move inward from the mm. FIG. 5 shows an example of an innermost position fixing structure of an optical pickup (14) used in a conventional CD disk drive. The innermost position of the optical pickup (14) is determined by the microswitch (17). Here, L is 24 mm [the objective lens (1
9) and the distance between the centers of the spindle motors (18)]. On the other hand, in the case of a write-once optical disc,
As shown in FIG. 2B, an area for disc information and the like is provided inside the lead-in section. That is, the innermost position is φ44.7 mm.

(C) Problems to be solved by the invention CDs, CD-ROMs,
In a rewritable optical disk device, when a write-once optical disk that requires recording on the inner circumference side from the lead-in portion is used and used, normal recording can be performed because the innermost circumference position is fixed. Not done. On the other hand, a signal is recorded when trying to play a CD in a write-once optical disc device whose innermost position is fixed at, for example, φ44.7 mm, with a mechanism that allows the pickup to move inward from the lead-in part. In order to reproduce in an area that has not been reproduced, a normal operation cannot be performed by the conventional signal processing algorithm.

(D) Means for Solving the Problems As a method for easily discriminating an optical disc, a reflectance change discrimination method and a color discrimination method can be considered.

In the case of optical disks having the same reflectance and different colors of the reflection film, the color discrimination method is effective. For example, a write-once optical disk uses a green reflective film, and a rewritable optical disk uses a blue reflective film.
For CD, CD-ROM, and laser disk, the color is silver or gold.
Therefore, the present invention uses an optical disc discriminating unit composed of a color sensor that transmits light in a predetermined wavelength range and an illumination unit that emits light in a wavelength range wider than the wavelength range of light transmitted by the sensor. And automatically changes the innermost stopper position of the optical pickup by a distance corresponding to each optical disk.

(E) Operation Since the innermost stopper position of the optical pickup is made variable as described above, various optical disks (CD, CD-ROM, laser disk, write-once optical disk, rewritable optical disk) can be used with the same optical disk recording and reproducing apparatus. Will be available.

(F) Embodiment One embodiment of the present invention will be described with reference to FIGS. 1, 2 and 3. FIG. FIG. 1 shows the configuration of the optical disc discrimination unit (1). Light from the illumination unit (2) that emits light in a wide wavelength range, such as natural light, is reflected by the reflective film of the optical disc (4) and received by the color sensor (3) that transmits only light in a predetermined wavelength range. . As shown in FIG. 2 (a), the color sensor (3) has blue, green,
Blue color sensor with red color filter (3-
1), green color sensor (3-2), red color sensor (3-
3), and each color sensor is electrically separated. As shown in FIG. 2, for example, light reflected from a reflective film of an optical disk (4) of different colors is reflected from a blue reflective film used in a rewritable optical disk. -1) only transmits light, and a single output signal is obtained as shown in (a) of the same figure (b), and the light reflected from the green reflective film used for the write-once optical disc is green. Only the color sensor (3-2) transmits light, and a single output signal is obtained as shown in FIG. In the case of silver (gray) reflective films used for CDs, CD-ROMs, and laser disks, the reflected light is reflected by a blue color sensor (3-1) and a green color as shown in (c) of FIG. Three output signals are obtained through the sensor (3-2) and the red color sensor (3-3). In the case of a gold (yellow) reflective film used for a CD, the reflected light passes through a green color sensor (3-2) and a red color sensor (3-3) to obtain two output signals. In this way, different output signals are generated in the color sensor depending on the color of the reflection film of the optical disk (4), and thus the type of the optical disk is determined.

Next, the outline of the position control will be described with reference to FIG. When the optical disc (4) is mounted on the optical disc drive, the discrimination output from the optical disc discrimination section (1) is input to the optical disc discrimination circuit (10), and the type of the optical disc (4) is discriminated. The result of the determination is sent to the control circuit (11), and an output value for setting a stopper position corresponding to each optical disk registered in advance is sent from the control circuit (11) to the motor drive circuit (12). . The rotation angle of the motor (13) is set by the output value of the motor drive circuit (12), and when the eccentric cam (16) connected to the motor (13) rotates by a predetermined amount, it is attached to the eccentric cam (16). The position of the stopper of the micro switch (17) changes by a predetermined amount. On the other hand, the pickup (14) is slidably mounted on the guide shaft (15). When the pickup (14) moves toward the inner periphery, the pickup (14) comes into contact with the micro switch (17) that has changed by a predetermined amount and stops moving.

(G) Effects of the Invention According to the present invention, two or more types of optical disks can be recorded / reproduced by a single optical disk device without externally operating, and the usability of the optical disk device is enhanced.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an optical disc discriminating unit according to the present invention.
FIG. 3 is a diagram illustrating the operation of the optical disc discriminator color sensor of the present invention, FIG. 3 is a diagram illustrating the operation of the present invention, FIG. 4 is a cross-sectional view showing a recording / reproducing area of the optical disc, and FIG. FIG. 3 is an explanatory diagram of an innermost position of an optical pickup of a CD optical disk device. 1 ... optical disc discriminating unit, 2 ... illuminating unit, 3 ... color sensor, 4 ... optical disc, 10 ... disc discriminating circuit,
11 control circuit, 12 motor drive circuit, 13 motor, 14 optical pickup, 15 guide shaft, 16 eccentric cam, 17 micro switch, 18 spindle motor, 9 …… Objective lens

Claims (1)

(57) [Scope of request for utility model registration] An optical disc apparatus for reproducing a plurality of types of optical discs whose recording or reproduction start positions differ according to the characteristics of the reflected light, wherein the type of the optical disc is determined by detecting the reflected light from the irradiated optical disc. A discrimination circuit; a control circuit for determining an output value for setting an innermost stopper position of an optical pickup corresponding to each optical disc based on a result of the discrimination by the optical disc discrimination circuit; and a motor based on an output value from the control circuit. , A motor driven by the motor drive circuit, a stopper for defining an optical pickup at a recording or reproduction start position corresponding to each optical disc, and a means coupled to the motor to move the stopper An optical disk device characterized by comprising: