JP4678145B2 - Playback speed switching circuit for disk device - Google Patents

Description

  The present invention relates to a disk device such as a DVD (Digital Versatile Disc) player, and more particularly to a playback speed switching circuit of a disk device having a switch for changing the display speed of a playback video.

  As an example of an input operation switch of an AV device, a non-contact switch is known that aims to make a feel of switching a button constant and to solve a switching problem (see, for example, Patent Document 1).

  This is configured to include a button having a coating on the back surface and a coiled switch that has a coil shape that generates a weak current by electromagnetic induction and senses a change in the weak current.

  As a result, the back side of the button approaches, so if the magnetic field on the switch side changes, the switch side causes a weak change in current. When this change in the weak current is detected, the switch is switched.

Therefore, since the buttons do not make physical contact, the feel is constant and the mechanical life is extended.
JP, 11-16464, A Moreover, the key switch device aiming at preventing the electric conduction failure which arises from deterioration of a contact point and increase in contact resistance is proposed (for example, refer to patent documents 2).

This key switch device is provided with a coil at the key top portion and the key bottom portion, and is configured to include a key switch and a detection circuit. The key switch presses the key by a current flowing through one of the coils. The coils are close to each other to generate a potential due to electromagnetic induction in the other coil, and while the key is not pressed, the coils are separated so that a potential due to electromagnetic induction is not generated in the other coil.

  The detection circuit detects a potential due to electromagnetic induction generated from the key switch.

According to the above configuration, since the operation is detected by the current generated by the electromagnetic induction by the coil of the key top part and the key bottom part, it is possible to detect the pressing of the switch even if dust adheres to the contact part. In addition, since it is non-contact, even if the number of keystrokes is increased, a problem of contact failure due to contact deterioration does not occur, and pressing detection failure can be prevented.
JP 2000-311541 A

  However, both the non-contact switch of Patent Document 1 and the key switch device of Patent Document 2 are configured so that the contact is non-contact. The display speed could not be varied easily.

  That is, when the playback video signal from the DVD player is output to the television receiver and the playback video is displayed on the screen, if the playback speed is to be switched, the fast-forward key must be pressed several times to change the playback speed. .

  Therefore, the user has to keep pressing the fast-forward key when the playback speed is increased or when it is desired to decrease the playback speed.

  The present invention has been made in view of the above problems, and provides a playback speed switching circuit for a disk device capable of freely switching the display speed of an image displayed on a monitor screen in accordance with the degree of pressing operation of a key switch. It is intended to provide.

In order to achieve the above object, a reproduction speed switching circuit of a disk device according to the present invention has a coil housed inside a switch body and a magnetic body portion provided in at least a part of a rod shape so as to penetrate the coil. A movable member whose one end passes through the switch body and is held so as to be able to advance and retreat in and out of the switch body, and an operation portion provided at one end of the movable member that is led out through the switch body And an elastic member that urges the movable member toward one end side and positions the operation portion at a fixed position spaced apart from the switch body by a predetermined distance, and the operation portion is subjected to an urging force of the elastic member. the key weak current corresponding to the degree of movement of the movable member to output a voltage generated in the coil due to the generated in the coil when it is pressed to the other end side with anti A switch, a signal converter for converting the output voltage of the key switch to the digital signal, and a control circuit for outputting a command signal comprising a code corresponding to the signal level of the digital signal from the signal conversion unit, the disk-type recording medium Control the entire disk device that reproduces the video and audio signals from the control circuit, and when a command signal is input from the control circuit, the playback speed is set to a preset double speed corresponding to the code included in the command signal. And a control unit that controls to perform fast forward playback or fast reverse playback by switching.

The disk drive reproduction speed switching circuit according to the present invention includes a differential amplifier that amplifies the output voltage of the coil connected to the other end of the coil, one end of which is connected to the ground, and outputs the amplified voltage to the signal converter. A data table stored in advance in association with each numerical data corresponding to each of a plurality of codes included in a command signal input from the control circuit and a plurality of stages of double speeds during reproduction. With reference to this, the reproduction speed is switched to a double speed corresponding to the code included in the command signal input from the control circuit .

As described above, according to the present invention, when the operation portion of the key switch is pressed , a voltage generated in the coil is output as a weak current corresponding to the degree of movement of the movable member corresponding to the pressing force is generated in the coil. A command signal including a code corresponding to the signal level of the digital signal obtained by converting the output voltage of the coil is output. The command signal is switched to a reproduction speed set in advance corresponding to the code included in the command signal. Since fast-forward playback or fast-rewind playback is performed, a disc device such as a DVD player does not need to perform the operation of pressing the fast-forward key or the fast-rewind key several times as in the prior art . fast playback speed for the desired speed simply by adjusting the degree of pressure, there is an effect that it is and simply switch over.

Further, according to the present invention, even when the output voltage of the coil is low, this output voltage is amplified by the differential amplifier, so that the degree of movement of the movable member is accurately detected and the reproduction speed of the desired double speed is ensured. You can switch to Furthermore, since a numerical data table corresponding to each of a plurality of codes included in the command signal and a plurality of stages of double speeds at the time of reproduction are associated with each other, a data table is stored in advance. The reproduction speed of double speed corresponding to the code included in the command signal input from the control circuit can be obtained easily and accurately.

  Hereinafter, embodiments of a playback speed switching circuit of a disk device according to the present invention will be described in detail with reference to the drawings.

  FIG. 1 is an electric circuit diagram showing a reproduction speed switching circuit of a disk apparatus according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view showing a schematic configuration of a switch.

The playback speed switching circuit of the disk device according to the present embodiment is applied to the DVD player 1 and is provided in the key operation unit of the remote controller 16.
Although not shown, the remote controller 16 has a power key for turning on / off the power, an open / close key for opening / closing a tray, a numeric keypad for inputting channels and numerical values, and menu items. Menu keys for display and other various function keys are arranged.

  The function keys include a play key, a stop key, a fast-forward key, a fast-rewind key, and a pause key, and are connected to the microcomputer control circuit 24 shown in FIG. 1 through a signal conversion unit.

  A transmitter circuit 25 is connected to the remote controller control circuit 24. When a command signal is input by pressing any of the keys, a light emitting device connected to the transmitter circuit 25 is output by outputting a corresponding code. Send an infrared signal from.

  The reproduction speed switching circuit 17 includes a key switch (fast-forward key) 18, a differential amplifier 22, and an A / D converter 23, and is connected to the remote control circuit 24.

  The key switch 18 includes a movable member 19 and a coil 20 and is provided in the key operation unit.

  The movable member 19 is made of a ferrite magnetic material, a magnetized iron core, or the like, and is formed in a cylindrical shape. The movable member 19 is provided with an operation portion 19 a having one end having a larger diameter than the movable member 19.

  The movable member 19 may be formed of a synthetic resin material on the operation portion 19a side and the other end 19b side from the substantially central portion with the magnetic material, and the two may be integrated.

  The movable member 19 has the other end 19b side inserted through the through hole 16b opened from the upper surface 19a of the main body to expose the operation portion 19a from the upper surface 19a, while the other end 19b side is held by the guide member 16c.

  The guide member 16c has an inner diameter slightly larger than the outer diameter of the movable member 19, and is fixed to the inner wall of the main body.

  A spring body 21 is housed between the bottom of the guide member 16 c and the other end 19 b of the movable member 19. The spring body 21 has an upper end engaged with the other end 19b of the movable member 19 and a lower end engaged with the bottom of the guide member 16c, so that the operation portion 19a is slightly spaced from the upper surface 16a. The elasticity is set.

  Thereby, when the operation part 19a is pressed with a finger, the movable member 19 is pushed along the inner peripheral wall of the guide member 16c according to the degree of the pressing force, and the spring body 21 is compressed. On the other hand, when the pressing of the operation portion 19a is loosened, the guide member 19 is pushed back by the elastic force of the spring body 21, and the operation portion 19a is returned to the original position.

  The coil 20 is formed in a cylindrical shape, has an inner diameter larger than the outer diameter of the movable member 19, and holds the movable member 19 in the main body in a state of being loosely inserted. The coil 20 has one end connected to the ground and the other end connected to the negative terminal of the differential amplifier 22.

  The differential amplifier 22 amplifies a voltage difference between the plus terminal and the minus terminal, and a constant voltage from the power supply unit is led to the plus terminal.

  An A / D converter 23 is connected to the output terminal so as to output the amplified voltage. The A / D converter 23 converts an analog input voltage into a digital signal and outputs it to the remote control circuit 24.

  The remote controller control circuit 24 outputs a code corresponding to the level of the digital signal to the transmission circuit 25 as a command signal. The transmission circuit 25 receives the command signal as described above and transmits an infrared signal from the light emitter.

  In the reproduction speed switching circuit 17 configured as described above, when the operation unit 19a is pressed with a finger, the movable member 19 is pushed and moves in the coil 20. Then, a weak current is generated in the coil 20 and a potential difference is generated between the coil 20 and the ground side, and a voltage is supplied to the negative terminal of the differential amplifier 22.

  The differential amplifier 22 performs amplification according to the difference between the voltages input to the plus terminal side and the minus terminal side, and sends the output voltage to the A / D converter 23. The A / D converter 23 sends a digital signal corresponding to the analog input level to the remote control circuit 24.

  The remote control circuit 24 causes the transmission circuit 25 to transmit a command signal corresponding to the level of the digital signal. Thereby, a command signal corresponding to the degree of pressing of the operation unit 19a can be transmitted as a control signal of the DVD player 1.

  When this command signal is received on the DVD player 1 side, the display speed of the video displayed on the screen of the monitor 11 can be switched by the video signal reproduced from the DVD 2.

  FIG. 3 is a block diagram showing an electrical configuration of the disk device.

  In the figure, reference numeral 3 denotes a drive system motor, which drives the DVD 2 to rotate. An optical pickup 4 sends information optically read from the track of the DVD 2 to a signal processing unit (not shown). This signal processing unit is connected to the reading unit 6 and the control unit 15, and performs signal processing on the read information and transmits it to each.

  Note that the operation speed of the motor 3 and the optical pickup 4 is controlled by the servo control unit 5.

  The reading unit 6 sends the compressed video / audio data read from the DVD 2 to the separation unit 7. The separation unit 7 separates the compressed video / audio data into a compressed video data bucket and a compressed audio data bucket and transmits the compressed video / audio data bucket to the decompression unit 8.

The decompressing unit 8 decodes the compressed video data bucket and the compressed audio data bucket separated by the separating unit 7 to decompress the original video / audio information.
The reading unit 6, separation unit 7 and decompression unit 8 are constituted by a general decoder IC.

  A video information output unit 9 converts the video data expanded by the expansion unit 8 into an NTSC or PAL color television signal so as to be displayed on the screen of a monitor 11 such as a television. Output.

  Reference numeral 10 denotes an audio information output unit, which sends out the audio data expanded by the expansion unit 8 to the speaker 12 for sound emission.

  Reference numeral 13 denotes a display circuit for OSD (On Screen Display), and an output is connected to the video information output unit 9. Then, based on the display control of the control unit 15, an OSD signal is output to the video information output unit 9 to display various operation methods including an operation guide, a menu, and a sign on the screen of the monitor 11.

Reference numeral 14 denotes a receiving unit that receives an infrared signal from the remote controller 16.
Reference numeral 15 denotes a control unit composed of a microcomputer, which includes a memory and a timer, and controls the operation of the entire apparatus. The control unit 15 is unidirectionally or bidirectionally connected depending on each part of the circuit and its function.
Then, the mode shifts to a mode corresponding to the command signal from the remote controller 16, and a control signal is sent to the servo control unit 5 to control the drive mechanism, thereby various kinds of normal playback, slow playback, fast forward, fast reverse and stop. Perform the action.

  In addition, operation control of the reading unit 6, the separation unit 7, the decompression unit 8, and the like is performed, the recording information of the DVD 2 is read, an image is displayed on the screen of the monitor 11, and sound is emitted from the speaker 12.

  Further, the control unit 15 stores the video display data in the buffer memory, and controls the double-speed reproduction by reading the data in the frame unit of the video display from the buffer memory according to the command signal of the remote controller 16. It has a configuration.

  That is, the DVD player 1 includes a data table in which numerical data and the stage of double speed reproduction are associated with each other in the memory.

  The numerical data is the level of the digital signal indicated by the code included in the command signal from the remote controller 16, and the stage of double speed reproduction is the speed of fast forward reproduction such as double speed, quadruple speed, eight times speed, and 16 times speed.

  The control unit 15 collates the data table of the memory based on the level of the command signal, and reads out data in frame units from the buffer memory according to the corresponding double speed.

  As a result, the playback image is displayed on the screen of the monitor 11 at a double speed corresponding to the degree of the pressing operation of the fast-forward key 18 by the user.

  Although the playback speed switching circuit of the disk device has been described as applied to the remote controller 16, it may be configured to be provided in a key operation unit provided in the main body of the DVD player.

  Moreover, although the case where the key switch is a fast-forward key has been described, it may be adopted as a fast-rewind key.

  The present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention.

1 is an electric circuit diagram showing a reproduction speed switching circuit of a disk device according to an embodiment of the present invention. FIG. It is sectional drawing which shows schematic structure of a key switch. It is a block diagram which shows the electric constitution of a disk apparatus.

Explanation of symbols

18 Key switch 19 Movable member 19a Operation part 19b Other end 20 Coil 23 Signal conversion part 24 Control means

Claims (2)

A coil housed in the switch body and a magnetic part provided in at least a part of a rod shape pass through the coil, and one end side penetrates the switch body and can move forward and backward in the switch body. A movable member held in the movable member, an operation portion provided at one end of the movable member that passes through the switch body and led out to the outside, and urges the movable member toward the one end side so that the operation portion is An elastic member positioned at a fixed position separated from the switch body by a predetermined distance, and the movable member moves when the operation portion is pressed against the biasing force of the elastic member toward the other end side. A key switch that outputs a voltage generated in the coil as a weak current corresponding to the degree is generated in the coil ;
A signal converter for converting the output voltage of the key switch into a digital signal;
A control circuit that outputs a command signal including a code corresponding to the signal level of the digital signal from the signal converter ;
The overall speed of the disk device that reproduces the video / audio signal from the disk-type recording medium is controlled, and when a command signal is input from the control circuit, a double speed set in advance in association with the code included in the command signal A control unit that performs control to switch to a playback speed of
A playback speed switching circuit for a disk device comprising: A differential amplifier that amplifies the output voltage of the coil connected to the other end of the coil, one end of which is connected to the ground, and outputs the amplified voltage to the signal converter;
The control unit is
Input from the control circuit with reference to a data table stored in advance by associating each numerical data corresponding to each of a plurality of codes included in the command signal input from the control circuit with a plurality of speeds at the time of reproduction. 2. The playback speed switching circuit for a disk device according to claim 1, wherein the playback speed is switched to a playback speed of double speed corresponding to the code included in the command signal .