JPH04313857A - Disk player - Google Patents

Abstract

PURPOSE:To make an optimum rise irrespective of the diameter of a disk and to shorten the rising time. CONSTITUTION:Sensors 14 and 15 for detecting the presence of the disk are arranged on a disk mounting part 10 of a player main body part 2. The sensors 14 and 15 are positioned inside and outside an 8cm disk from its outer circumferential edge respectively. In the case of reproducing operation by a pointing device 12 under the on-state of a safety switch 17, i.e., the closing state of an intermediate lid 9, whether the disk is present or not, and moreover if so, whether the disk is the 8cm disk or a 12cm disk are discriminated by a system controller based on outputs of the sensors 14 and 15 prior to commencement of the reproducing operation. Then, the servo gain of a spindle motor for rotatively driving a disk table 3 is controlled in accordance with the disk diameter. By this method, irrespective of the disk diameters, the optimum rise is carried out, and the rising time can be shortened.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disc player capable of playing back CD-I discs on which image information and the like are recorded in addition to audio information.

0002

[Prior Art] In addition to audio data, a CD (compact disc) contains image data (natural images, animation,
A CD that records computer graphics, etc.), text data, program data, etc., and can be operated interactively.
-I (CD Interactive) system has been proposed. The CD-I system has the ability to play back text, images, audio, computer data, etc.
It is expected to become a new form of media, as it can be used for AV consumer equipment centered on audio/video, electronic publishing centered on text, database services centered on information files, education/entertainment centered on dialog responses, etc. has been done.

Various specifications have been established for the CD-I system in order to maintain compatibility and enable it to be widely used for home use. In other words, in the CD-I system, a 16-bit CPU (equivalent to 68,000) is used as the CPU, and CD-RTOS (Compact DiscRe
al-Time Operating System)
is used, two trigger buttons and an XY device are used as input devices, and two systems, audio and video, are provided as output systems. In addition, CD-I players are equipped with regular music compact discs (CD-D
A) is defined so that it can be played.

0004

[Problem to be Solved by the Invention] In a CD-I player, for example, the rotation of a spindle motor that rotationally drives a disc table is controlled based on a phase comparison signal between a clock signal separated from a reproduction signal and a predetermined reference signal. be done. As a result, the entire spindle motor and its drive circuit constitute a PLL circuit, and the rotation of the spindle motor is controlled with high precision.

[0005]Currently, compact discs with a diameter of 8
There are two types of discs: cm and 12 cm. When playing these two types of discs, the load torque applied to the spindle motor changes. Therefore, the servo gain of the PLL circuit is automatically switched depending on the type of disk.

For example, it has been proposed to first rotate in a low gain state (corresponding to an 8 cm disc), and then switch to a high gain state (corresponding to a 12 cm disc) by checking the rotational speed after a certain period of time. There is. However, in this method, it is determined whether to increase the gain after the spindle motor has been rotated for a certain period of time, and when playing a 12 cm disc where the gain is switched, the rise time is The disadvantage is that it takes a long time.

Therefore, in the present invention, the start-up is made smooth and the start-up time is shortened regardless of the diameter of the disc to be reproduced.

[0008]

[Means for Solving the Problems] The present invention provides sensors for detecting the presence or absence of a disc, which are arranged inside and outside the outer peripheral edge of a small-diameter disc that can be placed on a disc table, and a sensor that detects the presence or absence of a disc. a disk diameter determining means for determining the diameter of the disk placed on the disk table based on the detection output of the sensor before the start of operation;
A gain control means is provided for controlling the servo gain of a motor that rotates the disk table based on the discrimination output of the disk diameter discrimination means.

[0009]

[Operation] The outputs of the sensors 14 and 15 differ depending on the disk diameter. Therefore, before starting the playback operation of the disc placed on the disc table 3, the sensor 14,
Based on the output of 15, the disc diameter can be determined. When the rotation of the disk table 3 is started, the control means 30 sets the servo gain in accordance with the disk diameter. Therefore, the start-up is smooth regardless of the disk diameter, and the start-up time is shortened.

0010

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. This example is an example applied to a CD-I player.

FIGS. 1 and 2 are perspective views showing the overall structure of the embodiment. The CD-I player 1 of this example has a liquid crystal display (LCD) 1 so that it can be easily carried outside.
9 are integrated, and the size and weight are reduced by integrating circuits and using chip parts. The overall size of this CD-I player 1 is, for example, 140 mm in width and 170 mm in length.
mm, and the height is 60 mm.

[0012] Inside the housing of the player body 2 of the CD-I player 1 is a disc table 3 on which a disc is placed.
A disk drive unit that rotationally drives the optical pickup 4, a pickup drive unit that moves the optical pickup 4 in the radial direction of the disk, a circuit board that processes the reproduction signal from the optical pickup 4,
It accommodates 68,000 CPUs, etc.

A headphone jack 5, a volume adjustment dial 6, and a power on/off switch 7 are provided on the front side 2A of the player body 2. The front left corner portion of the player main body portion 2 is formed higher than the other portions, and an open button 8 is disposed on the upper surface thereof.

Further, an inner lid 9 is rotatably disposed on the player body 2. As shown in FIG. 1, when the above-mentioned open button 8 is pressed with the inner lid 9 closed, a locking mechanism (not shown) provided at the front left corner of the player body 2 is pressed.
The locking state of the inner lid 9 is released, and the inner lid 9 is placed in an open state as shown in FIG. With the inner lid 9 open in this manner, a disc is loaded into or removed from the disc mounting portion 10 of the player main body 2 in which the disc table 3 is disposed at the center.

The inner lid 9 is provided with a window 11 made of a transparent material. As a result, even when the inner lid 9 is closed as shown in FIG.
It is now possible to check the rotational status of the disc installed in the machine. Trigger buttons 12A, 12 are provided on the front edge of the inner lid 9.
A pointing device 12 consisting of an X-Y device 12C and an X-Y device 12C is provided. The X-Y device 12C is configured so that the position in the X direction and the Y direction can be specified by pressing portions (indicated by triangle marks) that are offset vertically and horizontally from the center.

Furthermore, sensors 14 and 15 are provided in the disc mounting section 10 of the player main body section 2. As shown in FIG. sensor 14
is the outer peripheral edge of a disk with a diameter of 8 cm (hereinafter referred to as "8 cm disk") placed on the disk table 3 (Fig. 2
The sensor 15 is arranged on the inner side than the outer circumferential edge (shown in broken line), while the sensor 15 is arranged on the outer side of the outer peripheral edge thereof. As shown in FIG. 3A, the sensor 14 is configured with a light emitting element 14A and a light receiving element 14B adjacent to each other, while the sensor 15 is configured with a light emitting element 15A and a light receiving element 15B adjacent to each other.

Here, when no disk is placed on the disk table 3, the light from the light emitting element 14A is not supplied to the light receiving element 14B, and the light from the light emitting element 15A is also not supplied to the light receiving element 15B. When the 8 cm disc 16A is placed on the disc table 3, the light from the light emitting element 14A is reflected by the disc and supplied to the light receiving element 14B, but the light from the light emitting element 15A is not supplied to the light receiving element 15B. . When a disk 16B with a diameter of 12 cm (hereinafter referred to as "12 cm disk") is placed on the disk table 3, light from the light emitting element 14A is reflected by the disk and supplied to the light receiving element 14B, and light from the light emitting element 15A is The light is also reflected by the disk and supplied to the light receiving element 15B.

In this way, the sensors 14, 1 in each case
5 (outputs of the light receiving elements 14A and 15A) are different, so from the outputs of the sensors 14 and 15, the output of the disk table 3 is different.
Is there a disc placed on the 8cm disc 16?
A is placed or 12cm disk 16
It is possible to determine whether B is placed.

Furthermore, as shown in FIG.
A safety switch 17 is disposed adjacent to the opening button 8 disposed at the front left corner. The safety switch 17 is turned on by being pressed by the inner cover 9 when the inner cover 9 is closed as shown in FIG.

Furthermore, an outer cover 18 is rotatably disposed on the inner cover 9. This outer cover 18 can be opened manually. This outer cover 18 can be opened to an opening/closing angle of 90 degrees or more, and can be fixed at a predetermined opening/closing angle θ. A liquid crystal display 19 having a size of, for example, 4 inches is disposed on the back surface 18A of the outer cover 18. When the outer cover 18 is opened, the liquid crystal display 19 is exposed as shown in the figure, and the screen can be viewed.

An LCD drive switch 20 is provided on the back surface 18A of the outer cover 18. This LCD drive switch 20
The on/off of the liquid crystal display 19 can be controlled by the operation.

Further, on the back surface 18A of the outer cover 18, a display 21 is provided, which is made up of display elements 21A to 21C, such as light emitting diodes. The display elements 21A and 21B are mounted on the disk table 3 with 8cm disks 16A and 1, respectively.
The display element 21C is turned on when a 2 cm disc is placed on the disk table 3, and the display element 21C is turned on when no disk is placed on the disk table 3.

In the CD-I player 1 of this example, the CD-I
discs, CD-I/CD-DA discs (mixed discs of CD-I discs and CD-DA discs),
CD-DA discs (normal compact discs for music reproduction) can be played. Here, CD-
The data format of I will be explained.

[b1] Data structure CD-I records data in a format based on CD-ROM. The data recording unit is CD-RO
Like M, it is a block. One block corresponds to 98 frames. The capacity of one block is: 6 (number of audio data) x 2 (stereo 2 channels) x 2 (byte unit conversion) x 98 (number of frames) = 23
It is 52 bytes. The total recording capacity of a CD-I disc is 12 mm in diameter.
In the case of a cm disk, it will be approximately 640MB.

There are two types of CD-I data structures: Form 1 and Form 2. This corresponds to mode 1 and mode 2 of the CD-ROM, respectively.

[0026]Mode 1 in CD-ROM is as follows:
An error detection code and an error correction code are added to one block of data to enable powerful error correction. Mode 2 in CD-ROM is such that no error detection code or error correction code is added, allowing a large amount of user data. CD-I
With this, Form 1 and Form 2 can be specified for each block, and Form 1 and Form 2 can be mixed on one disk.

The CD-I format differs from the CD-ROM format in that an 8-byte subheader is provided at the beginning of the user data. In this subheader, blocks in which audio, images, and data are recorded are time-division multiplexed in units of blocks. In order to process these in real time, necessary data is written in duplicate and stored. This subheader consists of four items: file number, channel number, submode, and data type.

FIG. 4A shows the structure of Form 1. In form 1, a sink (12 bytes) is provided at the beginning, followed by a header (4 bytes), and further a subheader (8 bytes). After this, user data (2048 bytes) is provided, to which are added an error detection code EDC (4 bytes), P parity (172 bytes), and Q parity (104 bytes) for error correction. Form 1 has a high error correction ability and is suitable for handling data such as character data and program data for which error interpolation is not possible.

FIG. 4B shows the structure of Form 2. In form 2, a sink (12 bytes) is provided at the beginning, followed by a header (4 bytes), and further a subheader (8 bytes). After this, user data (2324 bytes) and a reserve area (4 bytes) are provided. This form 2 is suitable for handling data that can be error interpolated, such as audio data and video data.

As shown in FIG. 5, the subheader added to the beginning of user data includes the file number (2 bytes), channel number (2 bytes), and submode (2 bytes).
(byte) and data type (2 bytes).

[b2] Audio data writing CD-
Four modes are determined for writing audio data of I. The first mode has a sampling frequency of 44
．． 1kHz, quantization bit number 16 bits, current CD
-This is the same recording method as DA. This mode is intended for ultra high-fidelity playback.

In the second mode, ADP is used as the recording method.
CM (adaptive differential PCM) is used. The sampling frequency is 37.8 kHz, and the number of quantization bits is 8 bits. In this mode, it is possible to reproduce sound quality comparable to that of an LP record. Playback time: 2 hours in stereo, 4 hours in monaural
It's time. This mode is intended for high-fidelity playback.

In the third mode, ADP is used as the recording method.
CM is used. Sampling frequency is 37.8kHz
z, the number of quantization bits is 4 bits. In this mode, sound quality comparable to that of FM broadcasting can be reproduced. Playback time is 4 hours in stereo and 8 hours in monaural. This mode is
The purpose is high-fidelity playback for long periods of time.

In the fourth mode, ADP is used as the recording method.
CM is used. Sampling frequency is 18.9kHz
z, the number of quantization bits is 4 bits. Playback time is 8 hours in stereo and 16 hours in monaural. This mode is intended for speech reproduction.

[b3] Writing of video data Image data is processed as follows depending on the type of image data. In the case of a natural image, the sampling frequency of the luminance signal Y is 7.6 MHz, the sampling frequency of the color difference signals U and V is 3.8 MHz, and they are sampled at a ratio of 4:2:2. Each of the 8 bits is compressed to 4 bits and recorded, and is converted into 8 bits when played back.

In the case of graphics, a CLUT (color lookup table) is used. CLUT graphics are 256 colors (8 bits), 128 colors (7 bits)
There are three modes: 16 colors (4 bits) and 16 colors (4 bits).
You can select and use the color you need from approximately 16.8 million colors.

In the case of animation, run-length codes are used. This compresses image data using color data and the number of consecutive pixels. You can use this code to create full-screen animations.

[b4] Disc For CD-I discs, external diameter dimensions, center hole dimensions, mechanical dimensions such as thickness, optical parameters such as refractive index and reflectance, disc rotation direction, recording linear velocity, track shape, Recording parameters such as track pitch, usage environment, etc. are all the same as a normal compact disc for music (CD-DA).

Then, whether or not it is a CD-I disc is determined by checking the TOC (Table of Contents) in the lead-in area of the disc.
Of Contents). That is, CD-I disc or CD-I
/For CD-DA discs, P when POINT=A0
SEC is set to 10. On the other hand, in other disks, PSEC is set to 00 when POINT=A0. Therefore, from the PSEC when POINT=A0, it can be determined whether the disc is a CD-I disc, a CD-I/CD-DA disc, or another disc. Further, the control fields at POINT=A0, A1, and A2 of the CD-I disc are set to "01X0". CD-I/C
The control field at POINT=A0 of the D-DA disc is always set to "01X0", and the other control fields are set to "00X0". Therefore, from the control field, whether it is a CD-I disc or a
It can be determined whether it is a DI/CD-DA disc.

[b5] Since the hardware CD-I includes audio data and requires high-speed processing in real time, processing is performed using machine language. As the CPU for this purpose, the 68000 series, which is a 16-bit CPU developed by Motorola, is designated. In addition, CD-RTOS handles various files.
(real-time operating system) is based on OS9, and its programs are incorporated into the system in ROM. As input devices, at least two trigger buttons and an XY device are prepared. There are also two output systems: audio and video. Furthermore, the CD-I player is capable of playing music CD-DA.

Next, the internal configuration of the CD-I player 1 will be explained using FIGS. 6A and 6B. In the same figure, 8
The disc table 3 on which the cm disc 16A or the 12 cm disc 16B is placed is rotated by a spindle motor 31 at a constant linear velocity (CLV) during reproduction. The rotation of this motor 31 is controlled by a spindle servo circuit 32. In other words, the CD playback circuit 38
The clock signal reproduced by the system controller 30
A reference signal from the servo circuit 32 is supplied to the servo circuit 32 for phase comparison, and the rotation of the motor 31 is controlled based on the comparison error signal.

The output signals of the sensors 14 and 15 are also supplied to the system controller 30. Based on the output signals of the sensors 14 and 15, the system controller 30 determines whether a disk is placed on the disk table 3, and if so, determines whether it is an 8 cm disk 16A or a 12 cm disk 16B. be done.

The pointing device 12 and safety switch 17 described above are connected to the system controller 30. When the safety switch 17 is turned on (the inner lid 9 is closed) and before the pointing device 12 is operated and the playback operation is started, the light emitting elements 14A and 15A of the sensors 14 and 15 are activated by the system. The light is emitted under the control of the controller 30, and the system controller 30 makes the above-described determination at this point.

When it is determined that no disk is placed on the disk table 3, the system controller 30 controls the servo circuit 32, and the motor 31 does not rotate the disk table 3. On the other hand, when an 8cm disk 16A or a 12cm disk 16B is placed on the disk table 3, the servo circuit 32 is controlled by the system controller 30, and the servo gain is small (gain corresponding to the 8cm disk) or large (gain corresponding to the 12cm disk). (corresponding gain), and rotational driving of the disk table 3 by the motor 31 is started.

The system controller 30 has a display 21
are also connected, and the display elements 21A to 21C are connected according to the determination result.
is displayed selectively. Note that this determination result may be displayed on the liquid crystal display 19.

Furthermore, the recorded signal on the disk 16A or 16B is reproduced by the optical pickup 4. The optical pickup 4 is supported by a two-axis device. This two-axis device is controlled by a focus/tracking servo circuit 35. That is, the focus error signal and the tracking error signal detected by the preamplifier (matrix) 37 from the reproduction signal of the optical pickup 4 are supplied to the focus/tracking servo circuit 35, and the optical pickup 4 is supplied with two signals in the focus direction and the tracking direction.
A servo is applied to the axis.

Further, the optical pickup 4 is movable in the radial direction of the disk by a slide feed mechanism 34 using, for example, a linear motor. This slide feed mechanism 3
4 is controlled by a thread servo circuit 36. Although not mentioned above, direct current tracking deviation is caused by the servo circuit 36
The adjustment is made by controlling the slide feeding mechanism 34.

The operations of the servo circuits 35 and 36 are controlled by the system controller 30, and the optical pickup 4 can be accessed to a desired track position by track jumping or the like.

The reproduction signal from the optical pickup 4 is also supplied to a CD reproduction circuit 38 via a preamplifier 37. The CD reproducing circuit 38 includes a bit clock reproducing circuit, an EFM demodulating circuit, a CIRC error correcting circuit, and the like. In the CD reproducing circuit 38, the reproduced signal from the optical pickup 4 is EFM demodulated and further subjected to error correction processing. The operation of the CD playback circuit 38 is controlled by the system controller 3.
Controlled by 0. Note that control data such as subcode data detected by the CD playback circuit 38 is supplied to the system controller 30 and used for determining the type of disc, controlling access to the optical pickup 4, and the like.

The output of the CD reproducing circuit 38 is supplied to a CD-ROM reproducing circuit 39. The CD-ROM playback circuit 39 includes a sync detection circuit, a descrambling circuit, an error correction circuit, and the like. In the CD-ROM playback circuit 39,
A sink is detected and unscrambled. and,
The header address is checked and the desired block is accessed. In the case of Form 1, error correction processing is further performed. The operation of the CD-ROM playback circuit 39 is controlled by the system controller 30.

Further, 41 is a CPU for controlling the CD-I system, and a 68000 series CPU is used. A master controller 42 is connected to the CPU 41 . This CPU 41 and the system controller 30 described above are bidirectionally connected. A bus 43 is derived from the CPU 41. Note that the CPU 41 and the master controller 42 may be integrated into one chip.

Data reproduced by the CD-ROM reproduction circuit 39 is sent to the bus 43. A RAM 45A is connected to the bus 43 via video controllers 44A and 44B, respectively.
, 45B are connected. Further, a system ROM 46 and a backup nonvolatile RAM 47 are bidirectionally connected to the bus 43. Furthermore, an audio decoder 48 is connected to the bus 43.

Image data of the data reproduced by the CD-ROM reproduction circuit 39 is supplied to video controllers 44A and 44B under the control of the CPU 41, and a video signal is formed based on this image data. Video signals formed by video controllers 44A and 44B are each supplied to a video synthesizer 49 and synthesized. The synthesized video signal from the video synthesizer 49 is then supplied to the liquid crystal display 19 via the LCD drive circuit 50, and an image is displayed on the liquid crystal display 19. LCD for turning on/off the liquid crystal display 19
Drive switch 20 is connected to LCD drive circuit 50.

Also, audio data among the data reproduced by the CD-ROM reproduction circuit 39 is supplied to an audio decoder 48 under the control of the CPU 41. This decoder 48 is also supplied with audio data to be reproduced by the CD reproduction circuit 38. Audio data is ADPC
In the case of M, the decoder 48 decodes ADPCM. The audio data from the decoder 48 is D
After being converted into an analog signal by the /A converter 51, the signal is output to the output terminal (headphone jack) 5 via a low-pass filter 52 and an amplifier 53. The level of the audio signal delivered to the output terminal 5 is set by a volume adjustment dial 6.

As described above, according to this example, the diameter of the disk placed on the disk table 3 is automatically determined before the reproduction operation starts, and when an 8 cm disk or a 12 cm disk is placed, the spindle servo 32 is activated. The servo gain is set to be small (gain compatible with an 8 cm disc) or large (gain compatible with a 12 cm disc), and the disc table 3 is rotationally driven by the spindle motor 31. Therefore, the disc to be placed is 8cm
Regardless of whether it is a disc or a 12 cm disc, it can be started up smoothly and the startup time can be shortened.

Furthermore, according to this example, the disk table 3
If a disc is placed on the disc, it is automatically determined whether the disc is an 8 cm disc or a 12 cm disc, and the result of the determination is displayed on the display 21. Therefore, the disc size currently being used can be easily recognized, and especially as shown in Figure 1, the inner lid 9
This is valid during playback when the is closed.

Note that in the above embodiment, the sensor 14
, 15 are both arranged on the upper surface of the player main body 2, and the light emitting elements 14A, 15A and the light receiving elements 14B, 15B are arranged on the upper surface of the player main body 2. For example, the light emitting elements 14A, 15A
is arranged on the back surface of the inner lid 9, and the light receiving elements 14B, 1
5B may be arranged on the upper surface of the player main body 2 (as shown in FIG. 3B). In this case as well, the positions of the sensors 14 and 15 with respect to the outer peripheral edge of the 8 cm disk are the same as in the above embodiment.

Here, when no disc is placed on the disc table 3, the light from the light emitting element 14A is supplied to the light receiving element 14B, and the light from the light emitting element 15A is also supplied to the light receiving element 15B. When the 8cm disc 16A is placed on the disc table 3, the light from the light emitting element 14A is blocked by the disc and passes through the light receiving element 14.
However, the light from the light emitting element 15A is supplied to the light receiving element 15B. 12cm on disk table 3
When the disk 16B is placed, the light emitting element 14
The light from A is blocked by the disk and is not supplied to the light receiving element 14B, and the light from the light emitting element 15A is also blocked by the disk and not supplied to the light receiving element 15B.

In this way, the sensors 14, 1 in each case
5 (outputs of the light receiving elements 14A and 15A) are different, so from the outputs of the sensors 14 and 15, the output of the disk table 3 is different.
Is there a disc placed on the 8cm disc 16?
A is placed or 12cm disk 16
It is possible to determine whether B is placed.

[0060]

According to the present invention, the disc diameter is determined by the disc diameter determination means before the start of the disc playback operation, and when the rotation drive of the disc table is started, the servo gain of the motor is adjusted by the control means. Since it is controlled according to the disk diameter, it is possible to optimally start up regardless of the type of disk, and the start-up time can be shortened.

[Brief explanation of drawings]

FIG. 1 is a perspective view of the inner lid of the embodiment in a closed state.

FIG. 2 is a perspective view of the embodiment with the inner lid open.

FIG. 3 is a diagram for explaining sensor output.

FIG. 4 is a diagram showing the format of a CD-I sector.

FIG. 5 is a diagram showing the structure of a subheader.

FIG. 6 is a diagram showing the internal configuration of the embodiment.

[Explanation of symbols]

1 CD-I player 2 Player body part 3 Disc table 9 Inner lid 10 Disc mounting part 12 Pointing device 14,15 Sensor 16A 8cm disc 16B 12cm disc 17 Safety switch 18 Outer lid 19 Liquid crystal display 21 Indicator 30 System controller 31 Spindle motor 32 Spindle servo circuit

Claims (1)

[Claims] 1. A sensor for detecting the presence or absence of a disk, which is arranged inside and outside the outer circumferential edge of a small-diameter disk that can be placed on a disk table, and a sensor for detecting the presence or absence of a disk. A disk diameter determining means for determining the diameter of the disk placed on the disk table based on the detection output; and controlling a servo gain of a motor that rotationally drives the disk table based on the determined output of the disk diameter determining means. A disc player comprising gain control means.