JP2006040492A - Optical head and video camera - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce the operation sound of an optical disk device by reducing uncomfortable noise made due to the face wobbling of a recording film surface in the operation of an optical head. <P>SOLUTION: Between a case 1 of the optical head and an actuator cover 18, a buffering member 19 for relaxing the vibration is arranged to suppress the vibration of a cover to reduce the noise made due to the vibration of the actuator cover caused by the face wobbling of the recording film surface. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an optical disc apparatus that records or reproduces information on an optical disc, and more particularly to an optical head that optically detects information on the optical disc and converts it into an electrical signal, and a video camera using the optical head.

  First, the prior art will be described with reference to FIGS. 4 and 5 are an example of a plan view and a cross-sectional view of the configuration of an optical head using a conventional technique.

  The laser beam 3 emitted from the semiconductor laser 2 attached to the case 1 passes through the polarization beam splitter 4 and is converted into a parallel beam by the collimator lens 5. The laser beam 3 transmitted through the collimating lens 5 is reflected by the tatiage mirror 6, passes through the polarization diffraction grating 7, passes through the objective lens 8, and is condensed on the recording film surface of the optical disk 9. The laser beam 3 reflected from the recording film surface of the optical disk 9 passes through a path opposite to that described above, reflects the laser beam 3 by the polarization beam splitter 4 and changes its direction, and the light beam of the laser beam 3 is detected by a photodetector. 10, the information on the optical disk 9 is reproduced by the output of the light detector 10, and the position shift signal between the focal point of the laser beam 3 and the recording film surface of the optical disk 9 and the position shift signal with respect to the recording track are detected.

The polarization diffraction grating 7 and the objective lens 8 are mounted on a lens holder 11. One end of each of four suspensions 12 is fixed to the lens holder 11, and the other end is fixed to a holder 14. Further, a coil (not shown) is attached to the lens holder 11, and a voice coil motor is formed in combination with the yoke 15 and the magnet 17. The yoke 15 is coupled to the holder 14 by a support plate 16, and the holder 14 is fixed to the case 1 with an adhesive 13. The configuration is generally called a two-dimensional actuator, and a lens holder 11 elastically supported by a suspension 12 by passing a current through a coil (not shown), an objective lens 8 integrated with the lens holder 11, and a polarization diffraction grating 7 can move in a two-dimensional space in the direction perpendicular to the surface of the optical disk 9 and the radial direction of the optical disk 9. (For example, see Patent Documents 1 and 2)
The lens holder 11 is moved in the two-dimensional space based on the two positional deviation signals of the recording film surface and the recording track, so that the focal point of the laser beam 3 is correctly positioned on the recording film surface and the recording track of the optical disc 9.

Further, in another conventional technique, the two-dimensional actuator is covered so as to prevent damage to the suspension 12 of the two-dimensional actuator disposed in the case 1 and to prevent damage due to collision between the objective lens 8 and the optical disk 9. An actuator cover 18 is provided. By setting the position of the actuator cover 18 so that the actuator cover 18 and the lens holder 11 collide before the objective lens 8 collides with the optical disk 9, the objective lens 8 is prevented from being damaged. (For example, see Patent Document 3)
Japanese Patent Laid-Open No. 2003-257049 JP 2001-216665 A JP 2004-63031 A

  In recent years, optical disc video cameras equipped with an optical head have been commercialized. However, such a camera causes problems such as noise if a microphone equipped with vibrations generated from the inside of the camera is picked up.

  By the way, when the objective lens is driven by an actuator on the recording film surface in order to read / write information on the rotating optical disk, the actuator follows the movement of the surface of the recording film surface of the optical disk, causing vibration in the yoke. To do. The vibration of the yoke is transmitted to the optical head including the case through the support plate and the holder, and the case vibrates.

  Here, in the prior art described in the above-mentioned Patent Document 3, the actuator cover is fixed so as to sandwich the case with a side pressure using the spring property of the sheet metal by screwing or directly contacting the case, and the vibration of the case is The structure is transmitted to the actuator cover as it is. In addition, since the actuator cover attached to the case is made of a thin sheet metal or the like, the actuator cover itself acts just like a speaker diaphragm and amplifies vibrations, resulting in increased noise. was there.

  In particular, in the case of an optical disk video camera, the noise generated by the vibration results in the microphone mounted on the video camera picking up the noise of the optical head and lowering customer satisfaction.

  An object of the present invention is to provide an optical head having a mechanism for suppressing noise generated from an optical head by fixing an actuator cover and a case via a buffer material, and a video camera using the optical head.

  In order to solve the above problems, the present invention provides a light source, an objective lens for condensing the laser light emitted from the light source on the recording film surface of the optical disc, and the objective lens for condensing the objective lens at an arbitrary position of the optical disc. It includes a lens actuator having a function, an actuator cover that protects the lens actuator, and a case in which the actuator cover is disposed, and the actuator cover is fixed to the case via a cushioning material. That is, in order to prevent the vibration generated by the actuator transmitted to the case from being transmitted to the actuator cover, the actuator cover is reduced in vibration by a structure in which the actuator cover is fixed to the case via a cushioning material. The noise generated by the vibration plate can be reduced.

  In addition, by fixing the actuator cover and the case via a cushioning material, it is possible to reduce the noise generated by the optical head, and by mounting the optical head of the present invention on the optical disc video camera, unpleasant noise. It is possible to provide a video camera with less.

  According to the present invention, it is possible to provide an optical head with improved usability and a video camera using the optical head.

  Hereinafter, an optical head according to the present invention will be described with reference to the drawings.

  An embodiment of the present invention will be described in detail with reference to FIGS. FIG. 1 is a plan view of an optical head which is an embodiment according to the present invention, and FIG. 2 is a sectional view of the optical head which is an embodiment according to the present invention.

  The laser beam 3 emitted from the semiconductor laser 2 attached to the case 1 passes through the polarization beam splitter 4 and is converted into a parallel beam by the collimator lens 5. The laser beam 3 transmitted through the collimating lens 5 is reflected by the tatiage mirror 6, passes through the polarization diffraction grating 7, passes through the objective lens 8, and is condensed on the recording film surface of the optical disk 9. The laser beam 3 reflected from the recording film surface of the optical disk 9 passes through a path opposite to the above, reflects the laser beam 3 by the polarization beam splitter 4 and changes its direction, and the light beam of the laser beam 3 is detected by a photodetector. 10, the information on the optical disk 9 is reproduced by the output of the light detector 10, and the position shift signal between the focal point of the laser beam 3 and the recording film surface of the optical disk 9 and the position shift signal with respect to the recording track are detected.

  The polarization diffraction grating 7 and the objective lens 8 are mounted on a lens holder 11. One end of each of four suspensions 12 is fixed to the lens holder 11, and the other end is fixed to a holder 14. Further, a coil (not shown) is attached to the lens holder 11, and a voice coil motor is formed in combination with the yoke 15 and the magnet 17. The yoke 15 is coupled to the holder 14 by a support plate 16, and the holder 14 is fixed to the case 1 with an adhesive 13. In the actuator configured as described above, the lens holder 11 elastically supported by the suspension 12 by passing a current through a coil (not shown), the objective lens 8 integrated with the lens holder 11, and the polarization diffraction grating 7 are perpendicular to the surface of the optical disk 9. It is possible to move in a two-dimensional space in the right direction and the radial direction of the optical disc 9. The lens holder 11 is moved in the two-dimensional space based on the two positional shift signals of the recording film surface and the recording track, and the focal point of the laser light 9 is positioned on the recording film surface and the recording track of the optical disk 9.

  Here, in the optical head according to the present invention, an actuator cover 18 is provided so as to cover the two-dimensional actuator in order to protect the two-dimensional actuator, and the actuator cover 18 is sandwiched and fixed to the case 1 via the buffer material 19. Yes. As a fixing method, both surfaces of the buffer material 19, the actuator cover 18, and the case 1 are fixed with an adhesive.

  With this configuration, in order to prevent the vibration generated by the actuator transmitted to the case 1 from being transmitted to the actuator cover 18, the vibration of the actuator cover 18 is reduced, and the actuator cover 18 is generated as a diaphragm. Can reduce the noise.

  In the case of noise generated by the vibration generated by the actuator resonating with the actuator cover 18, it is also effective to make a hole or the like in the actuator cover 18 to shift the resonance frequency. However, the frequency of the vibration of the actuator that occurs due to the movement of the recording film surface of the optical disc is not constant. For this reason, the method by drilling may resonate at another resonance frequency, and in this case, the effect is small. On the other hand, the method according to the present invention is effective in reducing noise because vibration to the actuator cover 18 can be prevented regardless of the frequency of vibration.

  Next, an example of the configuration of an optical disc apparatus using the optical head will be described with reference to FIG. FIG. 3 is a front view of an optical disk drive using an optical head according to an embodiment of the present invention. In the optical disc apparatus 20, the optical disc 9 is attached to a spindle motor 21 and rotates, and recording / reproduction of video information on the optical disc 9 is performed by an optical head 24 electrically connected by a circuit board 22 and a flexible cable 23. . The optical head 24 is attached to the chassis 26 by two guide bars 25, and the rack 27 engages with the lead screw 29 of the seek motor 28 and can move in the radial direction of the optical disk 9.

  Since the lens holder 11 follows so as to position the focal point of the laser beam 3 on the recording film surface of the rotating optical disk 9, vibration is generated in the lens holder 11, and the vibration is applied to the magnet 17 and the yoke 15 forming the voice coil motor. Further, this vibration is transmitted to the case 1 via the holder 14 that fixes the yoke 15. Further, the vibration of the case 1 tends to be transmitted to the actuator cover 18, but the vibration to the actuator cover 18 is attenuated by the cushioning material 19 provided between the actuator cover 18 and the noise generated from the actuator cover 18 is thereby reduced. It can be reduced.

  Here, the buffer material 19 may be any material as long as it is an elastic material. For example, silicon rubber may be used.

  In this embodiment, both surfaces of the cushioning material 19 are fixed with an adhesive, but the present invention is not limited to this. For example, if an adhesive material such as a gel adhesive or silicon rubber is used as the buffer material 19, the actuator cover 18 can be fixed to the case 1 with the buffer material 19.

  The optical head according to the present invention is used in an optical disk device, a video camera using an optical disk, a playback device, and a recording / playback device.

Plan view of an optical head as an embodiment FIG. 3 is a cross-sectional view of an optical head that is an example. Front view of optical disk drive with optical head as embodiment Plan view of optical head in the prior art Sectional view of an optical head in the prior art

Explanation of symbols

1-case, 2-semiconductor laser, 3-laser light, 4-polarizing beam splitter,
5-collimating lens, 6-tachiage mirror, 7-polarization diffraction grating, 8-objective lens,
9- optical disc, 10- photodetector, 11- lens holder, 12- suspension,
13-adhesive, 14-holder, 15-yoke, 16-support plate, 17-magnet,
18-actuator cover, 19-buffer material, 20-optical disk device,
21-spindle motor, 22-circuit board, 23-flexible cable,
24-optical head, 25-guide bar, 26-chassis, 27-rack,
28-seek motor, 29-lead screw

Claims (3)

  A light source, an objective lens for condensing the laser light emitted from the light source on the recording film surface of the optical disc, a lens actuator for condensing the objective lens at an arbitrary position of the optical disc, and an actuator for protecting the lens actuator An optical head, comprising: a cover; and a case in which the actuator cover is disposed, wherein the actuator cover is fixed to the case via a cushioning material.   The optical head according to claim 1, wherein the buffer material is an elastic material. 2. An optical head according to claim 1, comprising: a microphone that collects audio; an imaging unit that captures video; and an audio head that records and reproduces audio collected by the microphone and video captured by the imaging unit. A video camera characterized by that.

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