JPH0543320U - Optical recording medium drive - Google Patents

Abstract

(57) [Summary] [Object] To provide a separable optical head having a structure in which foreign matter such as dust is unlikely to enter between a movable optical system and a fixed optical system and which is unlikely to adhere to an objective lens. [Structure] The movable optical system 2, the coarse movement mechanism 3, and the fixed optical system 4 which form the optical head are integrally covered by a dustproof cover 31. A through hole 32 that can be opened and closed by a shutter 33 is opened in a portion of the dust cover facing the objective lens 5. At the same time, an air introducing port 34 is opened outside the through hole opening position of the dustproof cover, a filter 35 is attached to face the air introducing port, and a fan 36 for drawing in air is provided inside the air introducing port. You can also

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an optical recording medium driving device, and more particularly, to a dustproof mechanism of an optical system in an optical recording medium driving device having a separation optical system.

[0002]

[Prior Art]

 Conventionally, in order to reduce the weight of the movable part of the optical head, to speed up the recording / reproducing operation and to reduce the power consumption, the optical head is a movable optical system having at least a laser oscillator and a detector, and at least an objective lens. There has been proposed an optical recording medium driving device that is separated into an optical system, and only this movable optical system is moved by a coarse movement mechanism in a direction toward or away from the fixed optical system.

FIG. 2 is an explanatory diagram of an optical head mounted in a conventionally known magneto-optical disk drive device, in which 1 is a magneto-optical disk and 2 is a magneto-optical disk 1 and is opposed to the magneto-optical disk. Reference numeral 4 denotes a movable optical system that is moved in the radial direction of the magneto-optical disk by the coarse movement mechanism 3, and reference numeral 4 denotes a fixed optical system that is arranged so as to face the movable optical system 2. The magneto-optical disc 1 is detachably mounted on a spindle motor (not shown) and is rotationally driven in a predetermined rotation mode. As shown in FIG. 2, the movable optical system 2 includes an objective lens 5 and a rising mirror 7 that raises the optical axis of the laser beam 6 emitted from the fixed optical system to the objective lens 5 side. On the other hand, the fixed optical system 4 includes a laser diode 8 which is a laser oscillator, a collimator lens 9 which converts the laser beam 6 emitted from the laser diode 8 into a parallel beam, a diffraction grating 10, and the laser beam 6 into a circular beam. The beam shaping prisms 11 and 12 for shaping, the first beam splitter 14 for guiding the reflected light 6a from the magneto-optical disk 1 to the information signal reading system 13, and the reflected light 6a from the magneto-optical disc 1 for the servo error signal. The second beam splitter 16 leads to the readout system 15. The information signal reading system 13 includes a half-wave plate 17 that rotates the S-polarized component and the P-polarized component of the reflected light 6a by 45 degrees, a first detector 18, a second detector 19, and a half-wave plate. The polarization beam splitter 20 guides the light emitted from the wave plate to the first detector 18, and the reflection mirror 21 that guides the light emitted from the half-wave plate to the second detector 19. Further, the servo error signal reading system 15 comprises a condenser lens 22, a cylindrical lens 23, and a third detector 24.

The laser beam 6 emitted from the laser diode 8 passes through the collimator lens 9, the diffraction grating 10, the beam shaping prisms 11 and 12, the second beam splitter 16, and the first beam splitter 14, and the fixed optical system 4 Is emitted from. The laser beam emitted from the fixed optical system 4 enters the movable optical system 2 and is focused on the recording layer of the magneto-optical disk 1 via the raising mirror 7 and the objective lens 5. The laser beam focused on the magneto-optical disk 1 is reflected by the recording layer and returned to the fixed optical system 4 via the objective lens 5 and the raising mirror 7. The reflected light 6a returned to the fixed optical system 4 is split into two by the first beam splitter 14 and is incident on the first detector 18 via the half-wave plate 17 and the deflecting beam splitter 20. It is incident on the second detector 19 via the reflection mirror 21 and the information signal or the like is read out. The reflected light 6a transmitted through the first beam splitter 14 is reflected by the second beam splitter 16 and is incident on the third detector 24 via the condenser lens 22 and the cylindrical lens 23, so-called astigmatism. The tracking error signal and the focus error signal are detected by the formula.

[0005]

[Problems to be Solved by the Invention]

 However, in the conventional separation type optical head, since the space between the movable optical system 2 and the fixed optical system 4 is not covered, foreign matter such as dust easily enters into the portion, and the movable optical system 2 and the fixed optical system 4 are not easily covered. There is a disadvantage that the laser beam transmitted between the system 4 and the system 4 is scattered and the utilization efficiency of the light is lowered, and the normal recording / reproducing operation is easily disturbed. Moreover, since the objective lens 5 is always exposed, the same inconvenience is likely to occur.

An object of the present invention is to solve the deficiency of the prior art and to provide an optical recording medium driving device provided with a separate type optical head having excellent durability and reliability.

[0007]

[Means for Solving the Problems]

 In order to achieve the above-mentioned object, the present invention provides a fixed optical system having at least a laser oscillator and a detector, a movable optical system having at least an objective lens, and a movable optical system approaching the fixed optical system or In an optical recording medium driving device equipped with a coarse movement mechanism that moves in a separating direction, the fixed optical system, the movable optical system, and the coarse movement mechanism are covered with a dustproof cover to oppose the objective lens of the dustproof cover. A through hole that can be appropriately opened and closed by a shutter is formed in the portion to be opened.

Further, in the same optical recording medium driving device as described above, an air inlet is opened outside the opening of the through hole of the dustproof cover, and a filter is attached so as to face the air inlet, and A fan is provided inside the air inlet to draw in air.

[0009]

[Action]

 If the fixed optical system, the movable optical system, and the coarse movement mechanism that compose the separable optical head are integrally covered with a single dust-proof cover, foreign matter between the fixed optical system and the movable optical system when not in use can be prevented. Invasion and adhesion of foreign matter to the objective lens are prevented. Further, if a through hole that can be appropriately opened and closed by a shutter is provided in a portion facing the objective lens, the movement of the objective lens is not hindered.

On the other hand, an air inlet is opened outside the through hole opening position of the dust-proof cover, a filter is attached so as to face the air inlet, and a fan for drawing air into the air inlet is installed. If provided, it is possible to draw clean air into the dust cover by activating the fan, which can raise the air pressure inside the dust cover. Therefore, by starting the fan before opening the shutter and opening the shutter in this state, it is possible to prevent foreign matter from entering and adhering when the shutter is open, that is, during use, and obtain a further dustproof effect. be able to.

[0011]

【Example】

 An embodiment of the present invention will be described below with reference to FIG. FIG. 1 is a perspective view of an optical head provided in the optical recording medium driving device of this example. In this drawing, 31 is a dust cover, 32 is a through hole for exposing an objective lens, 33 is a shutter, 34 is an air inlet, 35 is a filter, 36 is a fan, and other parts corresponding to those in FIG. Is displayed with the same reference numeral.

The dust-proof cover 31 is configured so as to integrally cover the movable optical system 2, the coarse movement mechanism 3, and the fixed optical system 4 which constitute the optical head, and is provided in a portion facing the objective lens 5. Is provided with a long hole-shaped through hole 32 over the movable range of the objective lens 5. One end of a shutter 33 is rotatably attached to one end of the through hole 32. The shutter 33 closes the through hole 32 when not in use, and the shutter 33 opens the through hole 32 when not in use. It is supposed to do. An air inlet 34 is provided outside the opening of the through hole 32 of the dustproof cover 31, and a filter 35 is attached so as to face the air inlet 34. Further, a fan 36 for drawing air into the dustproof cover 31 is provided at a portion of the inner surface of the dustproof cover 31 facing the air introduction port 34.

In this optical head, the movable optical system 2, the coarse movement mechanism 3, and the fixed optical system 4 are integrally covered with one dust cover 31, and a through hole 32 opened in the dust cover 31 when not in use. Since the shutter is closed by the shutter 33, foreign matter does not enter between the movable optical system 2 and the fixed optical system 4 and the foreign matter does not adhere to the objective lens 5 when not in use. Further, an air inlet 34 is opened outside the opening of the through hole 32 of the dustproof cover 31, a filter 35 is attached to face the air inlet 34, and a fan for drawing air into the inside of the air inlet 35. Since the air conditioner 36 is provided, it is possible to draw clean air into the dustproof cover 31 by activating the fan 36, thereby increasing the air pressure inside the dustproof cover 31. Therefore, if the fan 36 is started before the shutter 33 is opened and the shutter 33 is opened in this state, the clean air drawn into the dustproof cover 31 is exhausted to the outside from the through hole 32, and the atmospheric pressure causes the external air to be discharged. Since foreign matter is prevented from entering from the outside, it is possible to prevent foreign matter from entering and adhering during use. When the optical head is stopped, the objective lens 5 is housed in the dustproof cover 31, the shutter 36 is closed, and then the fan 36 is stopped to prevent foreign matter from entering the dustproof cover 31. Further, since the cooling of the coarse movement mechanism 3 such as a linear motor is promoted by the air flow obtained by driving the fan 36, the heating of the coarse movement mechanism 3 does not become a problem.

In the above embodiment, the air introduction port 34 with the filter 35 is provided outside the opening position of the through hole 32, and the fan 36 is provided inside the air introduction port 34. Even if the fan 35 and the fan 36 are not provided, at least the dustproof effect when not in use can be exerted, so that the durability and reliability are significantly improved.

[0015]

【The invention's effect】

 As described above, according to the present invention, the movable optical system, the coarse movement mechanism, and the fixed optical system are integrally covered by one dust cover, and when not in use, the through hole provided in the dust cover is used as a shutter. Since the foreign matter is prevented from entering the dustproof cover, the durability and reliability of the optical recording medium driving device can be improved.

[Brief description of drawings]

FIG. 1 is a perspective view of an optical head according to the present invention.

FIG. 2 is an explanatory diagram of an optical system of a conventionally known optical head.

[Explanation of symbols]

 2 Movable optical system 3 Coarse movement mechanism of movable optical system 4 Fixed optical system 5 Objective lens 31 Dust cover 32 Through hole for exposing objective lens 33 Shutter 34 Air inlet 35 Filter 36 Fan

Claims (2)

[Scope of utility model registration request] 1. A fixed optical system having at least a laser oscillator and a detector, a movable optical system having at least an objective lens, and a coarse movement mechanism for moving the movable optical system toward or away from the fixed optical system. In the optical recording medium drive device including the above, the fixed optical system, the movable optical system, and the coarse movement mechanism are covered with a dustproof cover, and a portion of the dustproof cover facing the objective lens can be appropriately opened and closed by a shutter. An optical recording medium driving device characterized by having a transparent hole. 2. The air inlet according to claim 1, wherein an air inlet is opened outside the through hole opening position of the dust cover, a filter is attached so as to face the air inlet, and air is introduced inside the air inlet. An optical recording medium driving device, characterized in that a fan for pulling in is provided.