JPH0447534A - Exchange method for lens cover in optical recording/ reproducing device - Google Patents

Abstract

PURPOSE:To prevent dust attached on an objective lens by providing a loadable/ unloadable light transmission member which covers the objective lens at the light emitting port of an optical head, and exchanging the member by using a jig for exchange. CONSTITUTION:The light transmission member 18 is fixed on a cover 15 with an adhesive, etc., and the cover 15 is mounted on the case of the optical head 1 removably by a groove 17. A new cover 15' is pressed by moving the tip 29 of a lever 23 which slides the knob 26 of the jig for exchange along an L-groove 25 in a direction of arrow A, and the new cover 15' is moved on a first arm 21, then, presses the cover 15 mounted on the optical head 1. The cover 15 is moved along the groove 17, and is housed in a second arm 30, and the cover 15' is moved along the groove 17 as pressing the cover 15, and is loaded on the optical head 1. Thereby, it is possible to easily exchange the light transmission member 8, and to surely prevent a fault due to the dust attached on the objective lens occurring.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention provides an optical recording and reproducing device that can easily remove dust on an objective lens in an optical head that adversely affects the recording and reproducing performance of an optical information recording medium. This article relates to a method for replacing a lens cover.

[Conventional technology]

In conventional optical recording and reproducing devices, since the optical information recording medium such as an optical disk is replaceable, it is difficult for dust to adhere to the optical disk and to the optical head inside the optical recording and reproducing device. There was a problem in that the recording and reproducing performance deteriorated.

For this reason, conventionally, methods have been used for optical discs, such as storing the optical disc in a cartridge to prevent dust from adhering to it, or wiping the optical disc directly with a soft cloth to remove dust.

However, dust attached to the objective lens provided near the light exit of the optical head cannot be easily removed because the optical head is generally housed inside an optical recording/reproducing device. For this reason, for example, JP-A-62-267
No. 931 describes a cleaning device that removes dust on an objective lens by rotating a brush.

[Problem to be solved by the invention]

The above-mentioned method of brushing off dust on the objective lens with a brush has a problem in that dust, cigarette smoke, oily deposits, etc. stuck on the objective lens cannot be easily removed.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for replacing a lens cover in an optical recording/reproducing apparatus, which allows easy removal of dust adhering to an objective lens provided near a light exit aperture of an optical head.

[Means to solve the problem]

In order to achieve the above object, in the present invention, an objective inside the optical head is provided at the light exit aperture of the optical head. A removable light-transmitting member is provided to cover the lens, and a replacement jig is used to replace the light-transmitting member to which dust has adhered, so that the light-transmitting member can be easily replaced with a new light-transmitting member.

[Effect]

By providing a removable light transmitting member that covers the objective lens at the light exit port of the optical head, dust adheres to the light transmitting member without directly attaching to the objective lens. The light transmitting member with dust attached can be easily replaced with another new light transmitting member using a replacement jig.
It is possible to reliably prevent troubles caused by dust and always perform good recording and playback.

〔Example〕

Hereinafter, one embodiment of the present invention will be described in detail using the drawings.

FIG. 1 is a cross-sectional view showing the basic structure of an optical disk and an optical head of an optical recording/reproducing apparatus according to an embodiment of the present invention.

In the optical head 1, a light beam 3 emitted from a semiconductor laser 2 passes through a collimator lens 4 and a beam splitter 5, its traveling direction is changed by a mirror 6 toward an objective lens 7, and the light beam 3 is condensed by the objective lens 7. A focal point 11 passes through the transparent member 8 and is placed on the signal recording surface 10 of the optical disc 9.
Tie. The light beam 3 reflected by the signal recording surface 10 passes through the light transmitting member 8 and the objective lens 7 again, and its traveling direction is changed by the mirror 6 toward the beam splitter 5, and further by the beam splitter 5, the light beam 3 passes through the light transmitting member 8 and the objective lens 7. Its direction is changed to reach the photodetector 12,
To reproduce the signal on the signal recording surface 10, or to play the signal on the signal recording surface 10
The positional relationship between the focal point 11 and the focal point 11 is detected. Objective lens 7
is attached to a holder 13 and is movable in the direction of an arrow 14 in response to the signal from the photodetector 12 so that the focal point 11 is focused on a predetermined position on the signal recording surface 10 . Although the moving mechanism is not shown in the drawings, the present invention is not particularly limited thereto, and any conventional moving mechanism may be used.

The light transmitting member 8 is fixed to the cover 15 with an adhesive or the like, and the cover 15 is removably attached to the optical radar case 16 through a groove 17.

If dust enters the inside of the optical recording/reproducing device, the optical head 1 is sealed internally by the optical head case 16, the light transmitting member 8, the cover 15, the semiconductor laser 2, and the photodetector 12. The light does not enter the inside of the optical head 1 and adhere to the optical component passage surface of the light ray 3, thereby reducing the light intensity at the focal point 11. Only one place, light transmitting member 8
Dust adheres only to the outside of the focal point 11, reducing the light intensity at the focal point 11. This dust can be removed to some extent by conventional methods such as brushes, but when used for a long period of time, a problem arises in that dust that cannot be removed by brushes adheres and the light intensity decreases. Therefore, failures can be prevented by replacing the light transmitting member 8 periodically or by detecting the presence of dust. The adhesion of dust to the light transmitting member 8 can be detected by detecting a decrease in the output of the photodetector 12, or by inserting a separate photodetector into the optical recording/reproducing device instead of the optical disc 9 and detecting the focus 11. A method of detecting the light intensity of the light transmitting member 8, a method of shining light on the surface of the light transmitting member 8 from another light source and detecting the reflected light intensity with the photodetector 12, etc. are possible. Either method can detect the adhesion of dust. Then, by displaying this on the outside of the optical recording/reproducing apparatus using an alarm lamp or the like, it is possible to notify that the light transmitting member 8 needs to be replaced.

The material of the light transmitting member 8 may be plastic, but considering the optical performance, 0. It is preferable to use parallel glass flat plates of about 1 mm to 0.5 mm with anti-reflection coating on both sides. Further, the cover 15 should preferably have a thermal expansion coefficient similar to that of the light transmitting member 8 in order to avoid straining the light transmitting member 8, and if glass is used for the light transmitting member 8, it is preferably made of an iron alloy, for example.

In addition, although the groove 17 is used in the embodiment to fix the cover 15 and the optical head case 16, other methods such as magnets, screws, adhesive tape, etc. may also be used.

To replace the light transmitting member 8, remove the cover 15 together with the optical radar case 16 and attach the cover 15 with the new light transmitting member 8 attached, but this replacement work may vary depending on the structure of the optical recording/reproducing device. This can be done by hand, but if the structure makes it difficult to do it by hand, it must be done with a jig.

FIG. 2 is a perspective view showing the structure of a replacement jig for the light transmitting member 8 in the embodiment shown in FIG.

As a conventional technique, a method of storing the optical disc 9 in a cartridge to prevent dust from getting onto the optical disc 9 has been described, and the replacement jig shown in FIG. 2 is suitable for an apparatus using such a cartridge.

The case 18 has a shape that can be inserted into an optical recording/reproducing device in the same way as a cartridge that houses the optical disc 9. The plate 19 is rotatably attached to the case 18 about a fulcrum of 2 degrees, and a cover 15' with a new light transmitting member 8' for replacement is attached to the first arm 21 of the plate. Further, a second arm 30 is provided at a position opposite to the left and right sides of the first arm 21 . A lever 23 is attached to the plate 19 and is rotatable about a fulcrum 22. The lever 23 is attached to the plate 19.
By passing through the groove 24 provided in the plate 19, the plate 19 is prevented from coming off. One tip 29 of the lever 23 is in contact with the cover 15', and the other extends outside the case through an L groove 25 provided in the case 18, and a knob 26 is attached to the tip.

FIG. 3 is a sectional view for explaining the operation of the replacement jig shown in FIG. 2.

The case 18 is inserted into the optical recording/reproducing device 28 as shown in FIG. 3(a). At this time, the optical head 1 with the light transmitting member 8 to which dust has adhered is positioned at an appropriate position. Furthermore, when the case 18 is inserted, the plate 19 is positioned inside the case 18 by the spring 31, so the optical head 1
never come into contact with. Next, when the knob 26 is lifted upward along the L groove 25, the plate 19 rotates about the fulcrum 20 in the direction of the optical head 1, as shown in FIG. 15' is located next to the cover 15 of the optical head 1.

In order to more accurately position the optical head 1, the first arm 21, and the second arm 3o at this time, it is desirable to provide a mating portion for positioning on both of them. In this state, the light transmitting member 8 can be replaced by sliding the knob 26 along the L groove 25.

The exchange operation will be explained in detail using Fig. 4.

As shown in FIG. 4(a), when the knob 26 is slid along the I groove 25, the sliding end 29 of the lever 23 is
direction and press the new cover 15'. The new cover 15' moves on the first arm 2] and pushes the cover 1ξ attached to the optical head 1. The cover 15 is shown in FIG. 4(b).
It moves along the groove 17 in the direction of the arrow B shown in , and is stored in the second frame 30 . Move the new cover 15' along the groove 17 while pressing the member 15, and
The rightward movement ends when the tip of 3 touches the optical head 1, and it is attached to the optical head 1. The replacement of the light transmitting member 8 is completed by moving the knob 26 in the opposite direction to the L groove 25 and pulling out the case 18 from the optical decoupling device 28. At this time lever 23
A spring (not shown) may be attached to the handle so that when the knob 26 is released, the handle automatically returns to the initial position.

FIG. 5 is a sectional view showing the basic structure of an optical disk 9 and an optical head 1 of an optical recording/reproducing apparatus according to another embodiment of the present invention.

In FIG. 5, the same elements as in the embodiment of FIG. 1 are given the same reference numerals.

The difference from the embodiment shown in FIG. 1 is that the cover 15 to which the light transmitting member 8 is fixed is attached to the holder 13 by a groove 17. Therefore, the light transmitting member 8 is the objective lens 7.
As it moves in the direction of arrow 14, it moves all at once. An expandable sealing material 32 is installed in the gap between the optical head case 16 and the holder 13 to prevent dust from entering the optical head 1. The embodiment shown in FIG. 5 is effective when the numerical aperture of the objective lens 7 is large and the distance between the objective lens 7 and the optical disk 9 is not large enough. For example, if the signal recording surface 10 moves vertically by 0.5 mm while the optical disk 9 is rotating, the objective lens 7 must also move vertically by 0.5IIffl. The thickness of the light transmitting member 8 is 0.3 mm.
In the case of the embodiment shown in FIG. 1, the distance between the optical disk 9 and the objective lens 7 is 0. 50.5+0.3=l 3
mm or more is required, but in the embodiment shown in Fig. 5, it is 0.5+
0.3 = 0.8 mm or more is good.

However, in the embodiment shown in FIG.
When replacing the light transmitting member 8, it is necessary to fix the position of not only the optical head l but also the holder 13, which makes replacing the light transmitting member 8 more difficult than in the embodiment shown in FIG.

〔Effect of the invention〕

As explained above, according to the present invention, a removable light transmitting member that covers the objective lens is provided at the light exit port of the optical head, and this can be easily replaced using a replacement jig. This has the effect that it is possible to prevent the problem of a reduction in light intensity due to dust adhering to the optical head, especially the objective lens.

Further, by using a cartridge-shaped replacement jig, there is an effect that the light transmitting member can be easily replaced even in an optical recording/reproducing device that cannot be replaced by hand.

Furthermore, since the cover with the new light transmitting member is used as part of the replacement jig, it can be replaced reliably, and there is no possibility that the light transmitting member will not be attached to the optical head by mistake. There is an effect that there is no.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view showing the basic configuration of an optical disk and an optical head of an optical recording/reproducing apparatus which is an embodiment of the present invention. FIG. 2 is a sectional view showing the structure of a jig for replacing a light transmitting member. Perspective views, Figures 3(a) and (b) are diagrams for explaining the operation of the replacement jig shown in Figure 2, and Figures 4(a) and (b) are diagrams for explaining the operation of the replacement jig shown in Figure 2. FIG. 5 is an enlarged view of the vicinity of the arm 21.30 for explaining in detail the operation of replacing the light transmitting member using the shown replacement jig, and is a diagram showing another embodiment of the present invention. ■...Optical head, 8...Light transmitting member, 15...Cover 18...Case, 19...Plate 21°30...Arm, 23...Lever

Claims (1)

[Scope of Claims] 1. Means for irradiating laser light for recording information on a recording medium on which information is optically recorded or reproducing information recorded on the recording medium; It has an objective lens that condenses light so as to focus on an information recording surface of a recording medium, and a light exit hole that is provided near the objective lens and through which the laser beam that has been condensed after passing through the objective lens passes. , a method for replacing the light transmitting member in an optical recording/reproducing device in which a light transmitting member is removably provided at the light exit port so as to cover the objective lens, wherein when replacing the light transmitting member, the optical recording member A flat plate having a first arm to which a replacement light-transmitting member can be attached, and a second arm for recovering the light-transmitting member attached to the light exit port, in a case having a shape that can be inserted into a playback device. an upper plate; and a lever attached at at least one point so as to be movable in a parallel direction on the plane of the plate, one end of which extends outside the case, and the other end of which extends to the first arm portion. By inserting a light-transmitting member replacement jig into the optical recording/reproducing device and moving one end of the lever, the first arm and second arm to which the replacement light-transmitting member is attached are replaced with the light-transmitting member. By positioning the replacement light transmitting member in a symmetrical position across the light exit port and moving one end of the lever in a direction parallel to the plane of the plate,
The other end of the lever pushes out the light-transmitting member attached to the light-emitting port by pushing it out in the direction of the light-emitting port, and the light-transmitting member held by the light-emitting port and attached to the light-emitting port is pushed out. , in an optical recording and reproducing device, characterized in that as the replacement light transmitting member moves toward the light exit opening, it is pushed out toward the second arm and held by the second arm. How to replace the light transmitting member.