JPS61214238A - Cleaning device of disc player - Google Patents

Abstract

PURPOSE:To eliminate easily water drops, dirt, etc. stuck to an objective lens to perform accurate reproducing by placing a prescribed cleaning member on a turntable instead of a disc to perform the reproducing operation. CONSTITUTION:A turntable 34 is so constituted that a cleaning member 39 is set instead of the disc. The cleaning member 39 consists of a substrate 39b and cleaning materials 39c, and shorter fur in the center part is brought into contact with a pickup 35, and longer fur on the outside peripheral part is brought into contact with a tray 33. When the reproducing operation is performed in this state, a player is stopped because of no reflected light after the objective lens and the tray 33 are cleaned with cleaning materials 39c. Thus, weater drops, dirt, etc. stuck to the objective lens are eliminated easily to perform accurate reproducing.

Description

Detailed Description of the Invention [Technical Field of the Invention] The present invention relates to a disc player such as an optical CAD (digital audio disc) playback device or a video disc playback device, and particularly relates to a method for cleaning an objective lens thereof. The present invention relates to a cleaning device.

[Technical Background of the Invention] As is well known, in the fields of audio equipment, image equipment, etc., in order to record and reproduce data with as high density and high fidelity as possible, information signals are converted into digital data and recorded on discs. Disc players are being actively developed in which the digital data is recorded on the disc, the digital data is read from the disc via an optical pickup, and the digital data is converted back into the information signal.

Here, FIGS. 8 and 9 show the principle of data reading means in the optical disc player as described above. That is, in both figures, 11 is a disk, and an aluminum coating layer 13 is coated on one surface of a substrate 12 formed in a disk shape of polycarbonate or the like.
It is formed by forming. And the disk 11
An objective lens 14 of an optical pickup is disposed opposite to the disk 11 on the side opposite to the side on which the aluminum coating layer 13 is formed.

First, FIG. 8 shows the optical path when the signal reflecting surface of the disk 11 is flat. That is, an ideal optical path in a focused state is such that a parallel reflected beam of approximately the same intensity returns to the incident beam, as shown by the broken line in FIG.

In addition, FIG. 9 shows a bit 1 on the signal reflecting surface of the disk 11.
1a is shown. That is, the ideal optical path in the focused state is such that the reflected beam is not scattered and returned to the objective lens 14 side with respect to the incident beam, as shown by the broken line in FIG.

[Problems with Background Art] However, when water droplets, dirt, etc. adhere to the surface of the objective lens 14, the following problems occur.

First, in FIG. 8, if water droplets 17 are attached to the surface of the objective lens 14 through which the incident light 15.16 passes, the reflected light 18.19 will be scattered as shown and returned to the objective lens 14. This will no longer be the case. Furthermore, if water droplets 22 are attached to the surface of the objective lens 14 through which the reflected light 21 with respect to the incident light 20 passes, the reflected light 21 will pass through the incident light 20.
It is no longer parallel to .

Furthermore, if dirt 24 adheres to the surface of the objective lens 14 through which the incident light 23 passes, a shadow will be formed on the path through which the reflected light 25 passes, as shown by hatching in the figure.

On the other hand, in FIG. 9, if water droplets 28 are already attached to the surface of the objective lens 14 through which the incident light 26.27 passes, the reflected light 29.30 will be scattered as shown, and the flat surface around the bit 11a will be scattered. This prevents the area from being irradiated. Furthermore, if dirt 32 adheres to the surface of the objective lens 14 through which the incident light 31 passes, a shadow will be formed as shown by hatching in the figure, and the anti-phase This results in a decrease in the amount of diffracted light.

Therefore, in either case of FIG. 8 or FIG. 9, if water droplets, dirt, etc. adhere to the surface of the objective lens 14, it becomes impossible to accurately read the digital data recorded on the disk 11. It is.

[Purpose of the Invention] This invention was made in consideration of the above circumstances, and is an extremely effective method that can easily remove water droplets and dirt particles attached to the surface of an objective lens, and can sufficiently contribute to accurate reproduction of discs. An object of the present invention is to provide a good cleaning device for a disc player.

[Summary of the Invention 1 That is, the disk player cleaning device according to the present invention is placed on a table on which a disk is placed and rotated together with the table, and is brought into contact with the objective lens of the optical pickup. By using the cleaning member, water droplets, dirt, etc. adhering to the surface of the objective lens can be easily removed, and this can sufficiently contribute to accurate reproduction of the disc.

[Embodiment of the Invention] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. In FIG. 1, 33 is a disc tray provided in a disc player, and a turntable 34 and a pickup 35 are inserted into a through hole 33a formed in the center of the disc tray. Here, the turntable 34 normally moves downward in the figure, but when a disk (not shown) is placed on the disk tray 33 and the playback operator is operated, the turntable 34 moves upward in the figure and touches the center of the disk. It is placed and held together with a clamper (not shown) to sandwich the disk, and is driven to rotate at a predetermined rotational speed by a disk motor 36.

Further, the pickup 35 is equipped with a laser diode, an optical system, an objective lens, a photodetector, etc. therein, and is supported by a screw shaft 37, although the details will be described later. The pickup 35 is moved in the radial direction of the disk by rotationally driving a pickup feed motor 38.

In addition, the pickup 35 is initially regulated to a position corresponding to the inner circumferential side of the disk, that is, a position shown in FIG. 1.

Here, a cleaning member 39 is placed on the turntable 34 in place of the disk, and is sandwiched between the turntable 34 and the clamper. This cleaning member 39 is a substrate 3 having approximately the same shape as the disk and having a through hole 39a formed in the center thereof through which the spindle 34a of the turntable 34 is inserted.
9b, and a cleaning material 39c provided on the surface of the substrate 39b facing the pickup 35.

Here, as the cleaning material 39c, short fibers made of, for example, pig hair or silicone-treated hair are used. As shown in FIG. 2, the cleaning material 39c has a length that reaches the upper end of the pickup 35 in FIG. 1 in an area r1 of the substrate 39b corresponding to the initial position of the pickup 35. The area r2, which is located on the outer periphery of the area r1, has a length that reaches the surface of the disc tray 33.

Here, FIG. 3 shows details of the pickup 35 and the electric circuit system around it.

That is, the pickup 35 includes a laser diode 35a, a collimating lens 35b, and a beam splitter 3.
5c, 1/4λ plate 35d, objective lens 35e, objective lens block 35f, focus actuator coil 3
5g, a magnet 35h, a photodetector 35i, etc.

Further, 40 in FIG. 3 is a focus search signal generation circuit, which generates a sawtooth focus search signal of, for example, about 1 to 282. This focus search signal is supplied to the focus actuator coil 351J via the phase compensation circuit 41 and amplifier 42, whereby the objective lens 35e is moved in the focus direction and a focus search is performed.

When the playback operator is operated, first, the turntable 34 is rotated by the action of the disk motor 36, and the focus search signal generation circuit 40 is rotated.
is driven and a focus search is performed. At this time, at the same time, laser light is emitted from the laser diode 35a, and after the emitted light is converted into parallel light by the collimating lens 35b, it passes straight through the beam splitter 35c.
The light is irradiated onto the objective lens 358 via the /4λ plate 35d.

In this case, if a disk is placed on the turntable 34, the irradiation light from the objective lens 35e is reflected by the disk, travels backward through the objective lens 35e, and passes through the 1/4λ plate 35d to the beam splitter 35c. The light is reflected at right angles, received by the photodetector 35i, and converted into an electrical signal.

Here, the output signal from the photodetector 35i is supplied to the focus error detection circuit 43 and also to the digital data generation circuit 44. Of these, the focus error detection circuit 43 is connected to the photodetector 3.
A focus error signal is generated based on the output signal of the 5i. Then, this focus error signal is transmitted to the objective lens 35e by the focus search operation.
When the signal reaches the vicinity of the in-focus position, it is supplied to the phase compensation circuit 41 in place of the focus search signal, and is subsequently used for focus servo.

On the other hand, the digital data generation circuit 44 waveform-shapes the electrical signal output from the photodetector 35i into binary digital data, and outputs the signal to the subsequent signal processing control circuit 45.
This is what is output to. This signal processing control circuit 45 is
For example, it is composed of a microcomputer, etc., and performs the operation of demodulating and reproducing the digital data generated by the digital data generation circuit 44, and the disc is reproduced here.

Next, the cleaning member 3 is placed on the turntable 34.
The operation when 9 is placed will be explained.

That is, when the playback operator is operated, the turntable 34 is rotated, and the cleaning member 39 is also rotated accordingly, and the objective lens 35e is moved in the focus direction by the focus search operation. Therefore, the objective lens 35e is
The surface will be cleaned by the cleaning material 39c of No. 9. Further, the disk tray 33 also includes:
The cleaning material 39C allows cleaning.

In this case as well, a light beam is emitted from the objective lens 35e, but since there is almost no reflected light, no output signal is generated from the photodetector 351. Therefore, the signal processing control circuit 45 operates to bring the disc player into a stopped state in the same way as when no disc is placed on the turntable 34.

Therefore, according to the configuration of the above embodiment, simply by placing the cleaning member 39 on the turntable 34 and operating the playback operator, the objective lens 35e and the disc tray 33 are automatically cleaned. After that, it is stopped and the objective lens 35 can be stopped very easily.
e and the disc tray 33 can be cleaned.
As a result, it becomes possible to perform accurate disc reproduction.

Next, FIGS. 4 and 5 show a second embodiment of the present invention. That is, the diameter of the cleaning member 39 is made large enough to cover the pickup 35 at the above-mentioned initial position, and the cleaning material 39c is provided in an area r3 corresponding to the initial position of the pickup 35, as shown in FIG. In this way, the objective lens 35e is cleaned. According to such a configuration, since the diameter of the cleaning member 39 is small, it is suitable for portability, and is particularly suitable for use in a portable type disc player or the like.

Further, according to the present invention, if the means shown in FIGS. 6 and 7 are provided on the disc player side, the cleaning action can be performed more effectively. First, in FIG. 6, 46 is a disk motor servo circuit, which applies a predetermined voltage signal to the disk motor 36 via the output terminal 41 to control the number of rotations of the disk. This disk motor servo circuit 46 is
A first function controls the rotation speed of the disk motor 36 at a speed corresponding to the normal playback mode, and a second function controls the rotation speed of the disk motor 36 at a speed lower than the speed corresponding to the normal playback mode. It has two functions.

Here, the first and second functions of the disk motor servo circuit 46 are selected by a changeover switch 48 that is switched by the output of the signal processing control circuit 45. That is, assuming that the cleaning member 39 is currently placed on the turntable 34, when the playback operator is operated, the signal processing control circuit 45 switches the changeover switch 48 to the illustrated state. At this time, the disk motor servo circuit 46 performs a second function, causing the disk motor 36 to rotate at a low speed.

Therefore, the objective lens 35e and the disk tray 33
etc. will be thoroughly cleaned. In this case, since the irradiated light from the objective lens 35e is not reflected, the disc player is controlled to be in a stopped state as described above.

Further, assuming that a disc is placed on the turntable 34, when the playback operator is operated, the changeover switch 48 is first switched to the state shown in the figure by the signal processing control circuit 45, so that the disc is in a low state. rotated at speed. In this case, since the irradiated light from the objective lens 35e is reflected, when a focus search operation is performed and the objective lens 35e reaches near the in-focus position, the focus error detection circuit 43 outputs a focus error signal.

Therefore, upon receiving the focus error signal, the signal processing control circuit 45 switches the changeover switch 48 to a state opposite to that shown in the figure, and sets the disc motor servo circuit 46 to the second state.
control to execute the functions of As a result, the disc is rotated at a normal rotational speed, and the disc is then played back.

Therefore, according to the configuration shown in FIG. 6, since the rotational speed of the disk motor 36 is slowed down to clean the objective lens 35e and the disk tray 33, cleaning can be performed more reliably. . Further, when a disk is mounted, the disk motor 36 is automatically switched to the normal rotational speed, so there is no need to provide a separate switch for cleaning, making handling extremely easy.

Next, in FIG. 7, a clean mode operator 49 is connected to the signal processing control circuit 45. As shown in FIG.

When the clean mode operator 49 is operated, the signal processing control circuit 45 causes the disk motor 36 to rotate at a low speed via the disk motor servo circuit 46 and rotates the disk motor 36 at a low speed via the feed motor servo circuit 50, as described above. The pickup 35 is moved slightly in the radial direction of the cleaning member 39.

In this way, cleaning of the objective lens 35e becomes even more effective.

Here, in the above explanation, short fibers made of pig hair, silicone-treated hair, etc. are used as the cleaning material 39c of the cleaning member 39, but this may also be, for example, silicone-treated cloth, etc. In short, Any material that does not damage the objective lens 35e may be used as appropriate.

It should be noted that the present invention is not limited to the above-described embodiments, and can be implemented with various modifications without departing from the gist thereof.

[Effects of the Invention] Therefore, as detailed above, according to the present invention, it is possible to easily remove water droplets, dirt, etc. adhering to the surface of the objective lens, and it is possible to easily remove water droplets, dirt, etc. that have adhered to the surface of the objective lens. It is possible to provide a cleaning device for a disc player.

[Brief explanation of drawings]

FIG. 1 is a side sectional view showing an embodiment of a cleaning device for a disc player according to the present invention, FIG. 2 is a plan view showing details of a cleaning member of the same embodiment, and FIG. 3 is an electrical diagram of the same embodiment. FIGS. 4 and 5 are block diagrams showing the circuit system; FIGS. 4 and 5 are side sectional views and plan views showing the second embodiment of the present invention; FIGS. 6 and 7 are for switching the rotational speed of the disk motor, respectively. FIGS. 8 and 9, which are block diagrams showing a functional disc player, are diagrams for explaining the problems of the conventional technology. DESCRIPTION OF SYMBOLS 11... Disk, 12... Substrate, 13... Aluminum coating layer, 14... Objective lens, 15
．． 16...Incoming light, 17...Water drop, 18.19...
・Reflected light, 20... Incident light, 21... Reflected light, 22
... Water droplets, 23 ... Incident light, 24 ... Dirt, 25
... Reflected light, 26.27 ... Incident light, 28 ... Water droplets, 29.30 ... Reflected light, 31 ... Incident light, 32
... Dirt, 33... Disc tray, 34... Turntable, 35... Pickup, 36... Disc motor, 37... Screw shaft, 38...
...Pickup feed motor, 39...Cleaning member, 40...Focus search signal generation circuit, 41
... Phase compensation circuit, 42 ... Amplifier, 43 ... Focus error detection circuit, 44 ... Digital data generation circuit, 45 ... Signal processing control circuit, 46 ... Disk motor servo circuit, 47 ...Output terminal, 48...
・Selector switch, 49...Clean mode operator, 5
0...Feed motor servo circuit. Applicant's agent Patent attorney Takehiko Suzue 111 Figure 112i1! II % 4 Illustration 5 Figure 8

Claims (1)

[Claims] An optical disc player configured to read information signals from a disc on which information signals are recorded via an optical pickup, which is placed on a table on which the disc is placed and rotated together with the table. A cleaning device for a disk player, comprising a cleaning member that comes into contact with the objective lens of the optical pickup.