JPH0555356U - Disc player - Google Patents

Abstract

(57) [Summary] [Purpose] To selectively set a servo loop circuit that obtains a servo loop characteristic that matches the disk size 1 detected by the pickup 2. [Structure] Detecting means for detecting a disk size, a first servo loop circuit 6 for obtaining a disk servo characteristic of the above detected first disk size 1a, and the above detected second
The second servo loop circuit 7 for obtaining the disc servo characteristic of the disc size 1b and the switch 8 for selectively setting the first and second servo loop circuits 6 and 7 are provided to stabilize the disc servo of the disc reproduction. It is configured to do.

Description

[Detailed description of the device]

[0001]

[Industrial application]

 The present invention relates to a disc reproducing device, and more particularly to a disc reproducing device suitable for obtaining disc servo characteristics for reproducing discs having different disc sizes.

[0002]

[Prior art]

 Conventionally, many disk reproducing apparatuses having the block diagram shown in FIG. 4 have been provided. In the figure, reference numeral 1 denotes a disc, which is rotatably driven by a disc motor 9, the recorded information of the disc 1 is read by a pickup 2, and the read reproduction data is servo-driven via an RF amplifier 3. It is supplied to the signal processing unit 4. Reference numeral 5 is an output terminal for a disk reproduction signal which is signal-processed by the servo / signal processing unit 4.

Reference numeral 10 denotes a microcomputer (hereinafter, referred to as a microcomputer) that controls the servo / signal processing unit 4. As is well known, the microcomputer 10 basically has a CPU, a ROM, a RAM, an input port and an output. It is composed of a port (not shown), and a program for controlling the CPU is written in the ROM. The CPU fetches external data required from the input port according to this program, or exchanges data with the RAM. It is possible to control the servo / signal processing unit 4 by performing arithmetic processing while exchanging data, and outputting the arithmetic processing data from the output port to the servo / signal processing unit 4.

Reference numeral 11 is a servo loop circuit to which signal processing data of a servo system signal is supplied by the servo / signal processing unit 4, and the disk motor 9 is controlled by the output servo signal of the servo loop circuit 11.

In the disc reproducing apparatus configured as described above, the emission beam of the pickup 2 is reflected on the surface of the disc 1, and the reflected light is photodetected by a photodetector to reproduce the recorded information on the disc 1. .. That is, the reproduction data from the pickup 2 is processed by the servo / signal processing unit 4 via the RF amplifier 3 and the reproduction signal is taken out from the output terminal 5.

Further, in the above-described rotation drive of the disk 1, the disk servo signal based on the rotation error signal which is signal-processed by the servo / signal processing unit 4 controls the disk motor 9 through the servo loop circuit 11, and the disk is constantly driven. The servo loop operation was performed so that the normal rotation of 1 was performed, and the disk servo characteristics were obtained.

[0007]

[Problems to be solved by the device]

 However, the above-mentioned conventional disk reproducing apparatus reads the recorded information in the disk 1, and the microcomputer 10 of the disk reproducing apparatus estimates the disk size based on the read recorded information data, and the loop of the servo loop circuit 11 Since the disk servo characteristic is obtained by switching the filter, there is a drawback that the disk 1 to be reproduced does not match the disk servo characteristic when the above-mentioned estimation of the disk size is an incorrect estimation.

In addition, since the disk size estimated by the microcomputer 10 cannot be confirmed in the process of performing the disk servo control by estimating the disk size from the reproduction information data of the disk 1, the user can confirm the correct normal disk servo. It also had the drawback of playing back without knowing whether or not the operation was being performed.

The present invention has been made in view of the above points, and the purpose thereof is to solve the drawbacks of the conventional example, detect the disk size by the pickup 2, and perform the servo matching the detected disk size. An object is to provide a disk reproducing device that can obtain loop characteristics.

[0010]

[Means for Solving the Problems]

 The disc reproducing apparatus of the present invention is a disc reproducing apparatus capable of reproducing discs having different disc sizes, and a detection means for moving the pickup from the inner circumference to the outer circumference of the disc to detect the disc size by the reflected light of the disc, A first servo loop circuit for obtaining a disc servo characteristic of a first disc size discriminated by a signal; a second servo loop circuit for obtaining a disc servo characteristic of a second disc size discriminated by the detection signal; It is provided with a switching device for selectively setting the first and second servo loop circuits, and is configured to stably perform the disk servo of the disk reproduction in which the disk size is discriminated.

[0011]

[Action]

 According to this invention, the laser light emitted from the pickup is reflected on the disk surface, the reflected light can be detected to detect the disk size, and the first disk discriminated by the disc size detection signal can be detected. The first servo loop circuit that obtains the disk servo characteristics can be selectively set by the switch, and an optimum servo loop circuit for reproducing the first disk can be formed.

Further, with respect to the second disks having different disk sizes, the second disk is discriminated by the detection signal by the reflected light of the light emitting laser light, and the optimum disk servo characteristic matched with the second disk is obtained. The obtained second servo loop circuit can be selectively set and reproduced by the switch.

As described above, the disc size can be automatically detected, and the servo loop circuit equipped with the servo filter suitable for the detected disc reproduction can be selectively set to perform the disc rotation servo. Since the detection can be automatically performed even when the disc reproducing device is not equipped with a disc, finer control can be performed in the disc reproducing operation.

[0014]

【Example】

 An embodiment of a disc reproducing apparatus according to the present invention will be described with reference to FIGS. FIG. 1 is a block diagram of the present invention, a perspective view of the disc showing the disc size detection of FIG. 2, and FIG. 3 is a timing chart showing the disc size detecting operation. The same parts as those of the conventional example are designated by the same reference numerals and the description thereof will be omitted.

In FIG. 1, reference numeral 6 denotes a first servo loop circuit to which output data obtained by signal-processing the servo data from the servo / signal processing unit 4 is supplied. The output servo signal of the first servo loop circuit 6 is shown. Operates so as to obtain a disk servo characteristic for the first disk, and 7 is a second servo loop circuit similar to the above, and the output servo signal of the second servo loop circuit 7 is the second disk. It operates to obtain the characteristics of the disk servo.

Reference numeral 8 is a switching device for switching and selectively setting the output servo signals of the first and second servo loop circuits 6 and 7 according to the disk size. The switching device 8 is controlled by the microcomputer 10. Switching operation is performed by a signal.

In FIG. 2, 1a is a first disc having a small disc size, and 1b is a second disc having a large disc size. Further, point A is the inner peripheral portion of the first disk 1a, B is the outer peripheral portion of the first disk 1a, and point C is the position of each point on the outer peripheral portion of the second disk 1b. Reference numeral 20 denotes a light emitting laser beam from the pickup 2.

In FIG. 3, reference numeral 21 is a light receiving characteristic for detecting a small-sized first disk, 22 is a light receiving characteristic for detecting a large-shaped second disk, and M1 and M2 receive reflected light from the disk. Light reception level values, N1 and N2 are non-light reception level values when there is no reflection from the disc, t ₁ is the movement time from point A to point B of pickup 2 by the light reception level M1 for detecting the first disc, t ₂ is the moving time from point A to point _C of pickup 2 according to the received light level M2 for detecting the second disk, t _C is the "size" of the disk size detection within the moving time from point A to point _C of pickup 2. Threshold value time.

In the disc reproducing apparatus configured as described above, the disc 1 mounted on the disc loading mechanism (not shown) is irradiated with the laser light 20 emitted from the pickup 2, and the laser light 20 is emitted from the surface of the disc 1. The disk size can be detected by detecting that the reflected light is reflected and returns to the pickup 2.

The detection of the disc size will be described with reference to FIGS. 2 and 3. As shown in FIG. 2, in a disc reproducing apparatus capable of mounting discs of two kinds of sizes, for example, first and second discs 1a and 1b, the point B becomes a point for detecting the disc size. The pickup 2 moves from the point A of the first disc 1a, that is, the starting point (point A) where the pickup 2 is first installed, to the point C on the outer periphery of the second disc 1b at equal time intervals, and the pickup 2 The laser light 20 emitted from the laser is emitted from the points A to C.

[0021] Above the point B, which is a point for detecting the two types of disk sizes of the first and second disks 1a and 1b, for example, the time zone t _C shown in FIG. It can be set as a “threshold”, and this “threshold” time t _C is recorded in the computer 10 in advance and set.

Now, for example, when the first disc 1a is mounted in the disc loading mechanism of the disc reproducing apparatus, during the time t1 during which the emitted laser light 20 from the pickup 2 moves from point A to point B, The microcomputer 10 judges the light receiving level M1 at which the laser light 20 emitted from the surface of the first disk 1a is reflected back to the pickup 2 and the microcomputer 10 determines that there is a disk between points A and B. You can judge.

On the other hand, when the pickup 2 passes the movement time t1 of the point B and exceeds the outer peripheral portion of the first disc 1a, the emitted laser light 20 is not reflected by the disc and is not received by the pick-up 2. the received light level N1 microcomputer 10 judges that there is no disk is detected, the microcomputer 10 measures the time t ₁ that detects the reflected light between the point a ~B point, the measurement time t ₁ of this is the When it is smaller than the “threshold value t _C ” (t _C > t ₁ ), the microcomputer 10 can detect the existence of the small-sized first disk 1a.

In addition, when the large-sized second disc 1b is mounted in the disc loading mechanism of the disc reproducing apparatus, even if the emitted laser light 20 from the pickup 2 moves from point A and exceeds point B, The light reception level M2 of the reflected light can be detected, and the microcomputer 10 determines the light reception level M2 of the reflected light until the pickup 2 passes through the point C, and the microcomputer 10 detects between the points A and C. Judge that there is a disc.

That is, the time t ₂ between the points A and C at which the microcomputer 10 detects the received light level M2 of the reflected light is larger than the “threshold value t _C ” (t _C <t ₂ ). It is possible to detect the presence of the large-sized second disk 1b.

When the disc 1 is not mounted in the disc loading mechanism of the disc reproducing apparatus, when the pickup 2 moves from the starting point A, there is no reflected light of the laser light 20 emitted from the pickup 2. The microcomputer 10 can detect that no disk 1 is mounted.

As described above, the microcomputer 8 detects the presence or absence of the disk 1 or the disk size, and switches the output servo signal of the servo / signal processing unit 4 so as to match the detected disk size. The first and second servo loop circuits 6 and 7 that form a servo filter that can be controlled to obtain a disk servo characteristic that matches the disk size can be selected and set, and optimum disk rotation can be performed automatically. Servo can be performed.

As described above, the first and second disks 1a and 1b having two kinds of disk sizes are detected and the optimum disk servo is operated. However, many kinds of disk sizes are mounted. Even in a reproducible disc reproducing device such as a CD disc or an LD disc, the invention can be applied to detect the disc size and control so as to obtain the optimum disc rotation servo characteristic.

[0029]

[Effect of the device]

 As described above, the disc reproducing device according to the present invention detects the disc size mounted in the disc reproducing device, and automatically switches the servo loop circuit so as to obtain the disc servo characteristic suitable for the detected disc. Therefore, there is an effect that it is possible to prevent an unstable disk servo operation such as the conventional one in which the disk size is estimated and the switching is set.

That is, the disc reproducing apparatus of the present invention has the effect that the disc can be reproduced by always setting and operating the optimum disc rotation servo, and more detailed disc reproduction control can be performed. There is also an effect that it is possible to easily recognize the presence or absence of the disc by the reflected light of the emitted laser light at the start point position of the pickup on the inner peripheral portion.

Moreover, it has excellent features such as a simple structure and easy implementation because it can be constructed at low cost.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a disc reproducing apparatus according to the present invention.

FIG. 2 is a perspective view of a disc for detecting a disc size.

FIG. 3 is a timing chart of disk size detection.

FIG. 4 is a block diagram showing a conventional example.

[Explanation of symbols]

1 disk 1a large-sized first disk 1b small-sized second disk 2 pickup 3 RF amplifier 4 servo / signal processing unit 5 output terminal 6 first servo loop circuit 7 second servo loop circuit 8 switcher 9 Disc motor 10 Microcomputer (microcomputer) 20 Emitting laser light 21 Detection light receiving characteristic of a small first disc 22 Detection light receiving characteristic of a large second disc A Inner circumference of first disc B First disc Outer peripheral area C Outer peripheral area of second disk M1, M2 Receiving level of reflected light N1, N2 Non-receptive level of reflected light t1 Moving time from point A to point B of pickup t ₂ Moving from point A to point C of pickup Time t _C Disk size detection “threshold” time

Claims (1)

[Scope of utility model registration request] 1. A disc reproducing apparatus capable of reproducing discs having different disc sizes, and a detecting means for moving the pickup from the inner periphery to the outer periphery of the disc to detect the disc size by the reflected light from the disc, and the detection signal. A first servo loop circuit for obtaining a disc servo characteristic of a first disc size determined by the above; a second servo loop circuit for obtaining a disc servo characteristic of a second disc size determined by the detection signal; And a switching device for selectively setting the second servo loop circuit, which is configured to stably perform a disc servo for disc reproduction in which a disc size is discriminated.