JP2002342970A - Optical disk device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical disk device capable of realizing a separation optical system suited for a high speed operation without any problems. SOLUTION: In a device fixed part 1, a light source 8 and an optical fiber 10 are provided, and a light from the light source 8 is emitted through the optical fiber 10 to a device movable part 3 side. Thus, a positional relation between the other end 10b of the optical fiber 10 to be a light emitting side and an actuator 17 only needs to be maintained constant irrespective of the seeking position of the actuator 17. Therefore, no strict adjustments are necessary, the light source 8 itself is installed near, for example a circuit board 4 without any particular layout limitations. Accordingly, the drawing distance of an electric signal for driving the light source 8 is greatly shortened, and a high-speed modulation driving can be executed for the light source 8. Although the optical fiber 10 is used, since it is in the device fixed part 1, bending resistance or the like causes no problem.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to an optical disk device.

[0002]

2. Description of the Related Art High density, high speed, and low power consumption of optical discs are progressing. Here, the optical system of the information recording / reproducing apparatus includes an integrated optical system in which all the optical elements are mounted on a movable portion, and a separation optical system in which an optical system is divided into a movable portion and a fixed portion.
Can be divided into two. The former is excellent in miniaturization, and the latter is lighter in the weight of the moving parts and suitable for higher speed.

An apparatus using a separation optical system is, for example, shown in FIG.
As shown in FIG. 7, an optical pickup (device movable portion) 102 that moves according to an access point of a medium 101, a fixed optical system 103 that is fixed to the device and does not move, a circuit board 104
And a flexible cable 105 for connecting the fixed optical system 103 and the circuit board 104. In the optical pickup 102, the medium 10
1 is provided with an actuator 107 including an objective lens 106 for condensing irradiation light. In addition, fixed optical system 1
03, a light source, for example, a semiconductor laser 108, a collimating lens 109 for collimating light emitted from the semiconductor laser 108 and guiding the light to the actuator 107 side;
A separation optical element 110 for separating the reflected light from the medium 101 from the light from the semiconductor laser 108 and a divided light receiving element 112 for receiving the reflected light separated by the separation optical element 110 via a lens 111 are provided. . on the other hand,
A laser driving circuit 113 for driving the semiconductor laser 108 and a waveform equalizing circuit 114 for obtaining a reproduction signal RF based on a light receiving signal of the divided light receiving element 112 are provided on the circuit board 104.
And a servo signal processing circuit 115 for obtaining a tracking / focusing signal for the actuator 107. Electrical connection between the fixed optical system 103 and the circuit board 104 is made by a flexible cable 105.

Here, the fixed optical system 103 is a medium 1
The optical axis of the optical pickup 102 is adjusted so that the optical axis guided to the fixed optical system 103 does not change even if the optical pickup 102 moves to guide the light focusing point to an arbitrary position on the optical system 01.

In the case of this system,. Optical axis adjustment between the optical pickup 102 and the fixed optical system 103 is required. An electric signal that is easily affected by noise is transmitted to the circuit board 104 by the flexible cable 105. High-speed electrical signals such as a light source modulation signal for recording are liable to be deteriorated by transmission through the flexible cable 105.

[0006] For this point, for example,
As shown in Japanese Patent Application Laid-Open No. 5-151610, an optical pickup movable section that moves in accordance with an access point of a medium, an optical system fixed section that is fixed to the apparatus and does not move, and a circuit board are separated. There is a proposal example in which an optical system fixing section is connected using a flexible polarization maintaining optical fiber. According to the configuration of the proposed example,
There is no need to route signals that are susceptible to noise,
There is also an advantage that processing can be immediately performed on a circuit board.

[0007] The proposed example of Japanese Patent Application Laid-Open No. 2000-67458 has the same configuration, but more specifically, quarter-wave plates are provided at both ends of a polarization-maintaining optical fiber to generate various signals. That is, an optical path from the semiconductor laser to the objective lens is provided on the polarization-maintaining optical fiber and on both sides thereof.
This is an example of a configuration using a 波長 wavelength plate, and after passing through an optical fiber, the light on the outward path and the return path are separated by using the polarization of the reflected light from the medium to generate various signals.

According to such a configuration, there is an effect that the optical axis is hardly shifted even if the positional relationship with the fixed optical system changes due to the movement of the optical pickup. In addition, since the optical fiber is used, the layout of the fixed optical system in the apparatus is relatively free, so that if the fixed optical system itself is brought close to the circuit board, the above problem can be solved.

[0009]

However, in recent years, as the miniaturization is progressing, the layout restrictions of the optical components in the fixed optical system are very severe, and it is practically difficult to lay out the light source and the light receiving element in the vicinity of the circuit board. However, the length of the flexible cable becomes longer, and a great effect on noise and signal deterioration cannot be expected.

Although the servo signal system, which is resistant to optical axis displacement due to the movement of the optical pickup but requires delicate position adjustment, is obtained from light passing through the optical fiber, the position adjustment of the installation of the optical fiber itself is not possible. The adjustment is necessary as before, and the adjustment is not lost.

In each of these publications, the optical path common to the outward path and the return path is replaced with an optical fiber, and the characteristics that can be freely bent are used. However, the problem with this configuration is the thickness of the optical fiber. An optical path to be replaced by an optical fiber should be constituted by an infinite system having a diameter of usually several mm, and this diameter is determined from the assembly accuracy of the optical element, the component accuracy, and the movable range of the lens. Of course, even today
If it can be reduced to less than mm, the size of the device can be reduced, but it can be said that it is difficult with the current technology.

If this optical path is replaced by an optical fiber, an optical fiber having a diameter larger than that of the light beam will be used, and the force required for bending the optical fiber will be much greater than that of a general flexible cable. That is, a force for moving the movable portion is required for the bending resistance of the optical fiber.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an optical disk apparatus capable of realizing a separation optical system suitable for high-speed operation without any trouble.

More specifically, the required accuracy of position adjustment is low, and a light source or RF light-receiving element that changes at high speed can be installed close to the circuit board. An object of the present invention is to provide an optical disk device which is resistant to noise and does not deteriorate high-speed signals.

It is still another object of the present invention to provide an optical disk apparatus which can greatly reduce the number of components of a fixed optical system and can significantly improve the degree of freedom of layout and assemblability.

Still another object of the present invention is to provide an optical disk device which can be easily replaced even when the light source is destroyed.

[0017]

According to the first aspect of the present invention,
A light source that is provided in the device fixing unit and emits irradiation light to the optical recording medium; an actuator mounted on the device movable unit including an objective lens that condenses the irradiation light on the optical recording medium; The directions are respectively positioned with respect to the light source and the actuator, and both ends thereof are disposed in the device fixing portion. Light emitted from the light source is incident from one end and emitted from the other end toward the actuator. An optical fiber.

Therefore, since the light source and the optical fiber are provided in the device fixing portion and the light from the light source is emitted to the device movable portion side via the optical fiber, the other end of the optical fiber on the emission side is connected to the other end. What is necessary is just to set so that the positional relationship with the actuator is kept constant regardless of the position displacement of the actuator, and strict adjustment is not required,
The light source itself is not subject to any special layout restrictions, and can be installed, for example, close to the circuit board. Therefore, the routing distance of electric signals for driving the light source can be greatly reduced, and high-speed modulation driving of the light source can be performed. In addition, since the light source driving circuit itself, whose size is strictly limited because it is better to be installed in the vicinity of the light source, can be mounted on the circuit board, so that the size limitation can be reduced. In addition, although an optical fiber is used, since it is located inside the device fixing portion, there is no problem in bending resistance and the like. As a result, a separation optical system suitable for high-speed operation can be realized without any trouble.

According to a second aspect of the present invention, there is provided a light source for emitting light to an optical recording medium, an actuator including an objective lens for condensing the light on the optical recording medium, mounted on a movable portion of the apparatus, and an apparatus fixed to the apparatus. A light receiving element for receiving an RF component in the reflected light from the optical recording medium, the direction of each end being the direction of the actuator and the RF;
And both ends thereof are disposed in the apparatus fixing portion so as to be positioned with respect to the light receiving element, and reflected light from the optical recording medium is incident from one end via the actuator, and the RF light is received from the other end. An optical fiber that emits light toward the element.

Therefore, an RF light receiving element and an optical fiber are provided in the apparatus fixing section, and the reflected light reflected from the optical recording medium and guided to the apparatus fixing section through the apparatus movable section is transmitted through the optical fiber in the apparatus fixing section. Since the light is guided to the RF light receiving element via the optical fiber, the positional relationship between one end of the optical fiber on the incident side and the actuator may be set so as to be kept constant regardless of the displacement of the actuator. No adjustment is required, and the RF light-receiving element itself is not subject to any special layout restrictions, and can be installed, for example, close to a circuit board, thereby significantly reducing the routing distance of high-speed RF signals that are susceptible to noise and improve quality. A good RF signal can be obtained. In addition, although an optical fiber is used, since it is located inside the device fixing portion, there is no problem in bending resistance and the like. As a result, a separation optical system suitable for high-speed operation can be realized without any trouble.

According to a third aspect of the present invention, in the optical disk device according to the first or second aspect, the optical fiber is provided detachably.

Therefore, since the optical fiber is detachable, when the light source or the RF light receiving element is defective or destroyed, the end of the optical fiber can be used as a cutout part at a component replacement level. At the time of assembling adjustment, the device moving part and one fixed optical system part, and the other fixed optical system and circuit board part are divided and advanced simultaneously. Shortening can also be expected.

According to a fourth aspect of the present invention, there is provided an actuator mounted on a device movable section including a light source for emitting light to an optical recording medium, an objective lens for condensing the light on the optical recording medium, and the device. A hologram element having a function of dividing the reflected light from the optical recording medium into a plurality of parts, and collecting the reflected light on the built-in divided light receiving elements,
The direction of each end is respectively positioned with respect to the actuator and the hologram element, and both ends thereof are disposed in the apparatus fixing portion, and reflected light from the optical recording medium is transmitted from one end through the actuator. An optical fiber that enters and exits from the other end toward the hologram element.

Therefore, basically the same as the second aspect of the present invention, the reflected light from the optical recording medium can be processed after transmitting the reflected light from the optical recording medium to the vicinity of the circuit board by an optical fiber by using a hologram element in the light receiving system. Only by adjusting the hologram element and the optical axis of the optical fiber, it is not necessary to strictly adjust the position of the servo divided light receiving element, and a good servo signal can be obtained. In addition, the routing distance of a high-speed RF signal that is susceptible to noise can be greatly reduced, and a high-quality RF signal can be obtained.
Since the number of optical components is significantly reduced, not only the assembling property but also the layout flexibility is increased and the size can be reduced.

According to a fifth aspect of the present invention, there is provided an actuator which includes an objective lens for condensing irradiation light on an optical recording medium and is mounted on a movable portion of the apparatus, and a light source is built in and emits light from the light source. A hologram element disposed on the device fixing portion and having a function of dividing the reflected light from the optical recording medium into a plurality of light beams and condensing the light beams on the built-in divided light receiving elements, and the direction of each end portion is Both ends thereof are disposed in the device fixing portion, which are positioned with respect to the actuator and the hologram element, and light emitted from the light source is incident from the other end and emitted from the one end toward the actuator, An optical fiber which receives reflected light from the optical recording medium from the one end via the actuator and emits the light toward the hologram element from the other end.

Therefore, in addition to the fourth aspect of the present invention, the hologram element also incorporates the light source and its emission function, and the adjustment of the optical axis of the light emitted from the light source is also included in the adjustment of the optical axis of the hologram element. Is unnecessary and the time can be shortened.

According to a sixth aspect of the present invention, in the optical disk device according to the fourth or fifth aspect, the one end of the optical fiber is integrated with the hologram element.

Therefore, since one end of the optical fiber is integrated with the hologram element, it is not necessary to adjust the optical axis between the hologram element and the optical fiber. In addition, the accuracy of the installation position of the hologram element may be low, and the number of components can be reduced and the assembling operation can be simplified, such as by directly soldering to the circuit board.

The invention according to claim 7 is the invention according to claims 4 to 6
In the optical disk device according to any one of the above, the hologram element has a function of reflecting a part of light from the light source inside the element, and receives light reflected from the light source for light amount monitoring for light source light amount control. Built-in element.

Therefore, since a part of the light from the light source is reflected inside the hologram element and made incident on the light quantity monitoring light receiving element built in the hologram element, it is unnecessary to install a new light receiving element and adjust the position thereof. A monitor signal for controlling the light emission power can be detected.

The invention described in claim 8 is the invention according to claims 4 to 7.
In the optical disc device according to any one of the above, the other end of the optical fiber is detachably disposed.

Accordingly, when the hologram element is defective or destroyed, the end of the optical fiber can be used as a cutout portion at the component replacement level.

[0033] The ninth aspect of the present invention provides the first to eighth aspects.
In the optical disc device according to any one of the above, the light source or the light source driving circuit for driving the light source provided in the device fixing portion is disposed in direct or indirect contact with a heat radiation member. I have.

Therefore, since the light source or the light source driving circuit is disposed in the fixing portion of the device and is in contact with the heat radiating member to radiate the heat, the rise of the temperature of the light source itself or the light source driving circuit and the inside of the device can be suppressed. It is possible to prevent performance degradation of the apparatus due to the fluctuation. That is, by arranging the light source in the device fixing portion, it is necessary to install the light source in the vicinity of the light source, and a light source driving circuit having a large heat generation amount or a member having a high heat radiation effect on the light source itself,
For example, it can be brought into contact with an external iron plate or the like.

According to a tenth aspect of the present invention, in the optical disk device according to any one of the first to ninth aspects, the light source provided in the device fixing section comprises a plurality of semiconductor lasers.

Therefore, since a plurality of semiconductor lasers are used as the light source disposed in the apparatus fixing section, even if a plurality of semiconductor lasers having different characteristics such as wavelengths and powers are mounted, parts mounted on the apparatus movable section and the like can be used. Since the weight does not change, the present invention can be applied to the above-described optical disk devices for various types of optical recording media.

[0037]

FIG. 1 shows a first embodiment of the present invention.
It will be described based on. FIG. 1 shows an example of a schematic configuration of an optical disk device according to the present embodiment, and schematically includes an apparatus fixing section 1 fixed to a frame or the like with screws or the like, and a spindle motor (not shown) or the like. A device which is moved in a radial direction of the optical recording medium 2 by a driving source such as a seek motor (not shown) in order to access an arbitrary portion of the optical recording medium 2 such as a CD or a DVD which is rotationally driven by the driving source. It is constituted by the movable part 3.

The device fixing section 1 includes a circuit board 4 and fixed optical systems 5 and 6. The circuit board 4 includes a servo signal processing circuit 7 for generating servo signals such as a focus error signal FE and a track error signal TE necessary for controlling a light spot at a specific location on the optical recording medium 2, and a light source (for example, , A semiconductor laser) 8 for emitting light with a predetermined reproducing / recording power (light source driving circuit)
9. Waveform equalization circuit (not shown) for improving the quality of RF signal reproduced from optical recording medium 2, demodulation circuit (not shown) for extracting data from RF signal after waveform equalization, and control of each circuit (Not shown) and the like are mounted.

The fixed optical systems 5, 6 which are separated into two parts
Are connected by an optical fiber 10 on the device fixing section 1. First, the one fixed optical system 5 has a light source 8 and an incident optical system 11 such as a lens that causes light emitted from the light source 8 to enter from one end 10 a of the optical fiber 10.
And a fixed base 12 for fixing one end 10 a of the optical fiber 10 on the fixed optical system 5. The other fixed optical system 6 has a fixed base 13 for fixing the other end 10 b of the optical fiber 10 on the fixed optical system 6,
An optical system 14 such as a lens for aligning a light beam axis emitted from the device toward the device movable portion 3 with a light beam axis on the device movable portion 3 is provided. The fixing bases 12 and 13 only need to have a function of fixing the end of the optical fiber 10, and the structure and the like are not particularly limited. In this manner, the light emitted from the light source 8 enters the one end 10a of the optical fiber 10 and the light emitted from the other end 10b of the optical fiber 10 Both ends 10a and 10b of the optical fiber 10 are positioned and fixed so as to irradiate the lens.

The apparatus movable section 3 includes a reflecting mirror 15 for condensing light on the optical recording medium 2 and an objective lens 16. The position of the objective lens 16 is controlled by a control signal transmitted from the servo signal processing circuit 7. Actuator 17 to control
Is installed. In addition, a separation optical element 18 for guiding the reflected light of the optical recording medium 2 returned from the actuator 17 to an optical path different from the incident light from the light source 8 side, and a servo signal formed by a part of the reflected light from the optical recording medium 2 A mirror 20 which separates the component from the RF signal component and guides the component to a servo split light receiving element 19;
An optical system such as a condenser lens 21 is mounted. However, the servo signal processing does not need to have the configuration shown in FIG. 1 in particular, and may be mounted on the fixed optical system 6, for example. Although not particularly shown, an RF light receiving element and a peripheral optical system for detecting an RF signal component separated from a servo signal component in a part of the reflected light from the optical recording medium 2 include a device movable unit 3 and a fixed optical system. It may be mounted on any of the optical systems 5 and 6.

In the servo signal processing, in order to specify an accurate position on the optical recording medium 2, it is necessary to accurately adjust the reflected light on the servo divided light receiving element 19. When the optical path is extended using an optical fiber, the positional accuracy of fixing the end of the optical fiber greatly affects the optical spot position adjustment accuracy on the divided light receiving element for servo. Therefore, it is better to determine the servo signal processing system by assembling the optical element without passing through a movable part such as an optical fiber. On the other hand, the light intensity of the light source processing system is important, and the positional deviation tolerance is larger than that of the servo signal processing system.

The fixed optical system 6 is limited in layout in order to match the optical axis of the movable section 3 of the apparatus, and a position adjusting mechanism and the like should be provided. On the other hand, the fixed optical system 5 may be disposed in the immediate vicinity of the circuit board 4, and the optical fiber 1
If the mutual positional relationship between 0 and the light source 8 is maintained, it is not necessary to precisely adjust the position of the entire fixed optical system 5. As a result, the group of optical components having a large limitation in terms of layout is small, so that the degree of freedom in layout is large and miniaturization is possible.

Therefore, according to the present embodiment, the light source 8 and the optical fiber 10 are provided in the apparatus fixing section 1 so that the light from the light source 8 is emitted to the apparatus movable section 3 via the optical fiber 10. Therefore, the positional relationship between the other end 10b of the optical fiber 10 on the emission side and the actuator 17 may be set so as to be kept constant irrespective of the seek position of the actuator 17, and strict adjustment is required. Not required, the light source 8 itself is not subject to any special layout restrictions,
For example, it can be installed near the circuit board 4. Therefore, the routing distance of the electric signal for driving the light source 8 can be significantly reduced, and the high-speed modulation driving of the light source 8 can be performed. Further, the laser drive circuit 9 itself, whose size is strictly limited because it is better to be installed close to the light source 8, can be mounted on the circuit board 4, so that the size limit can be reduced. Further, although the optical fiber 10 is used, since the optical fiber 10 is located inside the device fixing section 1, there is no problem in bending resistance or the like. As a result, a separation optical system suitable for speeding up
Can be realized without hindrance.

Incidentally, in the present embodiment, the optical fiber 10 can be detached at the fixing bases 12 and 13 where the both ends 10a and 10b of the optical fiber 10 are fixed. Of course, the higher the mounting accuracy, the better. Since the optical fiber 10 is removable, the apparatus movable section 3 and the fixed optical system 6 can be set as a set to perform assembly adjustment, and then can be combined with the circuit board 4 and the fixed optical system 5. The replacement operation can be performed by using the end of the optical fiber 10 as a cutout portion without reassembling in the case of a component failure or destruction.

In the case where the light source 8 is arranged in the device fixing section 1 (fixed optical system 5), the light source 8 itself generating heat by laser emission and the heat radiation method of the laser driving circuit 9 for supplying a driving current therefor are provided. In consideration of the above, only by arranging the light source 8 and the drive circuit 9 thereof, the light source 8 can be directly or indirectly contacted with a heat radiating member such as an exterior metal plate or a chassis having a high heat radiating effect or a rubber having a high heat conductivity. Can be provided. As a result, it is possible to suppress an increase in the temperature of the light source 8 itself or its laser drive circuit 9 and the inside of the device, and to prevent performance degradation of the device due to temperature fluctuation.

A second embodiment of the present invention will be described with reference to FIG. The same portions as those described in the first embodiment are denoted by the same reference numerals, and description thereof is omitted (the same applies to the following embodiments). The present embodiment mainly focuses on RF signal detection processing.

First, in addition to the servo signal processing circuit 7 and the like on the circuit board 4, a waveform equalizing circuit 31 for improving the quality of the RF signal reproduced from the optical recording medium 2 is provided. In the apparatus movable section 3, the half mirror 32 divides the reflected light from the optical recording medium 2 into two for the servo signal and the RF signal, and is reflected by the half mirror 32 and further reflected by the mirror 20. Servo divided light receiving element 1 for receiving a servo signal component in reflected light and constituting a servo signal detection system
9. The condensing lens 21 for the servo divided light receiving element 19 is also mounted on the apparatus movable unit 3.

Further, on the fixed optical system 5, an RF light receiving element 33 is provided. The two fixed optical systems 5 and 6 are separated from each other by the optical fiber 34 on the device fixing unit 1.
Are connected by One fixed optical system 6 has a fixed base 13 for fixing one end 34 a of the optical fiber 34 on the fixed optical system 6, and a light reflected from the optical recording medium 2,
And an optical system 35 such as a lens for aligning the light axis with respect to the one end 34a with the light axis on the apparatus movable unit 3 side so as to make the light enter from one end 34a via the actuator 17 and the half mirror 32. The other fixed optical system 5 includes an RF light receiving element 33 and an optical fiber 3.
The light emitted from the other end 34b of the fourth light receiving element
Focusing optical system 36 such as a lens for focusing
And a fixed base 12 for fixing the other end 34 b of the optical fiber 34 on the fixed optical system 5.

As described above, regardless of the seek position of the actuator 17, the reflected light from the optical recording medium 2 enters the one end 34a of the optical fiber 34 and the reflected light emitted from the end 34b of the optical fiber 34 Ends 34a, 3 of the optical fiber 34 so as to irradiate the light receiving element 33 for use.
4b are respectively positioned and fixed.

In this embodiment, the light source processing system (light source and peripheral optical system) is not particularly shown, but
Or fixed optical system 5 or 6.

In the servo signal processing, in order to specify an accurate position on the optical recording medium 2, it is necessary to accurately adjust the reflected light on the servo divided light receiving element 19. When the optical path is extended using an optical fiber, the positional accuracy of fixing the end of the optical fiber greatly affects the optical spot position adjustment accuracy on the divided light receiving element for servo. Therefore, it is better to determine the servo signal processing system by assembling the optical element without passing through a movable part such as an optical fiber. On the other hand, the light intensity is important in the RF signal processing system, and the allowable value of the displacement is larger than that in the servo signal processing system.

The fixed optical system 6 is limited in layout in order to match the optical axis of the movable section 3 of the apparatus, and a position adjusting mechanism and the like should be provided. On the other hand, the fixed optical system 5 may be disposed in the immediate vicinity of the circuit board 4, and the optical fiber 1
If the mutual positional relationship between 0 and the RF light receiving element 33 is maintained, strict position adjustment of the entire fixed optical system 5 is not required. As a result, the group of optical components having a large limitation in terms of layout is small, so that the degree of freedom in layout is large and miniaturization is possible.

Therefore, according to the present embodiment, the RF light receiving element 33 and the optical fiber 34 are provided in the device fixing unit 1, and are reflected from the optical recording medium 2 via the device movable unit 3. Since the reflected light guided to the (fixed optical system 6) side is guided to the RF light receiving element 33 via the optical fiber 34 in the device fixing unit 1, one end 34a of the optical fiber 34 on the incident side and the actuator 17 May be set so as to be kept constant irrespective of the seek position of the actuator 17, no strict adjustment is required, and the RF light receiving element 33 itself is not subject to a special layout limitation, For example, it can be installed near the circuit board 4. Therefore, the routing distance of a high-speed RF signal that is susceptible to noise can be significantly reduced, and a high-quality RF signal can be obtained. In addition, although the optical fiber 34 is used, since the optical fiber 34 is in the apparatus fixing section 1, there is no problem in bending resistance and the like. As a result, a separation optical system suitable for high-speed operation can be realized without any trouble.

A third embodiment of the present invention will be described with reference to FIGS. In this embodiment, the actuator 17 of the apparatus movable section 3 is the same as that of the above-described embodiment, but the servo divided light receiving element 19 and its peripheral optical system are not mounted on the apparatus movable section 3. . Instead, a hologram element 41 having both the function of a split light receiving element for servo and the function of a light receiving element for RF is mounted on a circuit board 4 which is one of the device fixing portions 1. Also,
An optical fiber 42 is provided in the apparatus fixing section 1 and connects the apparatus movable section 3 side to the hologram element 41. Here, one end 42 a of the optical fiber 42 is connected to the hologram element 41, and the other end 42 b is placed on the fixed optical system 43 so that the optical axis of the optical fiber 42 is aligned with the optical axis of the apparatus movable unit 3. Adjusted and fixed by. An optical system 45 includes a beam axis adjusting lens and the like.

Next, the hologram element 41 of the present embodiment
FIG. 4 shows an example of the configuration. This is because the light receiving elements A to D corresponding to the divided light receiving elements for servo, the light source 46 and a part of the light emitted from the light source are converted into a special grating (diffraction grating) 47.
And a light-quantity monitoring light-receiving element 48 for receiving the light reflected by the light-emitting device. The grating 47 can condense the light to a desired position or emit the light emitted from one point from the hologram element 41 in a parallel light state. In addition, there is a type in which various optical systems are integrated with a lens or a mirror. An advantage of this is that no new adjustment is required because the hologram element itself is a completed optical system.

As described above, the servo signal generation system requires precision in adjustment. In particular, since the positional accuracy for fixing one end of a movable body such as an optical fiber is coarse, adjustment is difficult. In this regard, in the present embodiment, one end 42a of the optical fiber 42
The hologram element 41 which is integrated with the hologram element (see the broken line in FIG. 3) and whose focus point has already been adjusted is preferable because no new adjustment is required. On the other hand, the other end 42b side of the optical fiber 42 is made removable by a fixing base 44.

The necessity of separately mounting the servo signal generation system on the apparatus movable section 3 is eliminated. A plurality of (electric) signal lines 49 from the hologram element 41 are respectively connected to the laser drive circuit 9, the waveform equalization circuit 31, and the servo signal processing circuit 7 mounted on the nearest circuit board 4. The light-quantity monitoring light-receiving element 48 is connected to the laser drive circuit 9 in order to monitor the amount of light emitted from the light source 46 and to always use the light source 46 to emit light with a desired amount of light.

A conventional servo split light receiving element 100 is shown in FIG.
As shown in (a), 8 divisions based on 4 divisions, etc.
There are various methods depending on the servo signal processing method. In the hologram element, the light receiving element arrangement can be determined relatively freely.
As shown in FIG. 5B, each of the light receiving elements A to D, the light source 46,
Further, it is desirable that the light receiving elements 48 for monitoring the amount of light be arranged in a line. This is because terminals arranged on a plane are easy to use at the connection between the hologram element 41 and the circuit board 4. Of course, each of the light receiving elements A to D and the light source 4
6, and the arrangement of the light quantity monitoring light receiving elements 48 is not limited to this.

Therefore, according to the present embodiment, basically the same effects as in the first and second embodiments can be obtained.
In particular, since the reflected light from the optical recording medium 2 is transmitted to the circuit board 4 by the optical fiber 42 using the hologram element 41 for the light receiving system and then processed, the hologram element 41 and the optical axis of the optical fiber 42 are aligned. Just by adjusting, it is not necessary to strictly adjust the position of the divided light receiving element for servo, and a good servo signal can be obtained. In addition, the routing distance of a high-speed RF signal that is susceptible to noise can be greatly reduced, and a high-quality RF signal can be obtained. Since the number of optical components is significantly reduced, not only the assembling property but also the layout flexibility is increased and the size can be reduced. In particular, in the present embodiment, the hologram element 41 also incorporates the light source 46, and the adjustment of the optical axis of the light emitted from the light source 46 is also included in the adjustment of the optical axis of the hologram element 41. Time can also be reduced.
Furthermore, since a part of the light from the light source 46 is reflected inside the hologram element 41 and made incident on the light quantity monitoring light receiving element 48 built in the hologram element 41, it is unnecessary to install a new light receiving element and adjust its position. The monitor signal for controlling the light emission power of the light source can be detected.

Further, since one end 42a of the optical fiber 42 is integrated with the hologram element 41, the optical axis adjustment between the hologram element 41 and the optical fiber 42 becomes unnecessary. In addition, the installation position accuracy of the hologram element 41 may be low, and the number of parts can be reduced and the assembling work can be simplified, such as by directly soldering to the circuit board 4. On the other hand, the optical fiber 4
Since the other end 42b of the optical fiber 42 is detachably disposed, for example, when the hologram element 41 is defective or broken, the other end 42b of the optical fiber 42 can be used as a cutout part at a component replacement level.

A fourth embodiment of the present invention will be described with reference to FIG. In the present embodiment, a plurality of, for example, two semiconductor lasers 8a and 8b for emitting laser beams having different wavelengths are used for the light source 8 disposed in the fixed optical system 5 and the like in the device fixing section 1, and these are used. Semiconductor lasers 8a and 8b
Is emitted to one end 10a using a common optical fiber 10 and emitted from the other end 10b side, thereby being transmitted to the actuator 17 side.

More specifically, as shown in FIG. 6, the beam splitter 51 changes the optical path by using the difference in the polarization of the outgoing light emitted from the two semiconductor lasers 8a and 8b, and
The light is made incident on one end 10a of the optical fiber 10 via 2 or the like.

At present, in a reproducing apparatus that supports both the CD system and the DVD system, lasers having different wavelengths are required. Therefore, two semiconductor lasers are mounted on the apparatus movable section. Moreover, it becomes heavy and is not suitable for high-speed access. In this regard, according to the present embodiment, since the light source 8 can be disposed in the device fixing unit 1, the weight of the device movable unit 3 does not change even if any number of semiconductor lasers are mounted, and there is no hindrance to high-speed access. I won't come.

[0064]

According to the first aspect of the present invention, the light source and the optical fiber are provided in the device fixing portion, and the light from the light source is emitted to the device movable portion side via the optical fiber. The positional relationship between the other end of the optical fiber on the side and the actuator should be set so as to be kept constant regardless of the displacement of the actuator, no strict adjustment is required, and the light source itself has a special layout. There is no limitation, for example, it can be installed close to the circuit board, so that the routing distance of the electric signal for driving the light source can be greatly reduced, high-speed modulation driving of the light source can be performed, and The size of the light source drive circuit itself, which had a strict size limit because it was better to be mounted on a circuit board, could be reduced, and the use of optical fibers was also possible. But since it is the device fixing part, without the bending resistance or the like becomes an issue, after all, the separation optical system method suitable for high speed can be realized without any problem.

According to the second aspect of the present invention, an RF light receiving element and an optical fiber are provided in the apparatus fixing section, and the reflected light reflected from the optical recording medium and guided to the apparatus fixing section through the apparatus movable section is provided. Since the light is guided to the RF light receiving element via the optical fiber in the device fixing part, the positional relationship between one end of the optical fiber on the incident side and the actuator is set to be constant regardless of the displacement of the actuator. It does not need to be strictly adjusted, the RF light receiving element itself is not subject to any special layout restrictions, and can be installed, for example, close to a circuit board. The distance can be greatly reduced, a high-quality RF signal can be obtained, and an optical fiber is used. Without end, the separation optical system method suitable for high speed can be realized without any problem.

According to the third aspect of the present invention, in the optical disk device according to the first or second aspect, the optical fiber is detachable, so that the end of the optical fiber is cut when a light source or an RF light receiving element is defective or destroyed. It can be handled at the part replacement level as a cutting part, and at the time of assembly adjustment, it is divided into the movable part of the device and one fixed optical system, and the other fixed optical system and the circuit board part, and proceeds simultaneously, and finally the light Since a fiber connection method can be used, it is possible to expect a reduction in assembly adjustment time.

According to the fourth aspect of the invention, basically the same effects as those of the second aspect of the invention can be obtained.
Using a hologram element for the light receiving system, the reflected light from the optical recording medium can be processed after being transmitted by an optical fiber up to the circuit board, so only by adjusting the hologram element and the optical axis of the optical fiber, the servo split light receiving element can be used. It is possible to obtain a good servo signal without the need for strict position adjustment, and it is possible to significantly reduce the routing distance of a high-speed RF signal that is vulnerable to noise, to obtain a high-quality RF signal, and to use optical components. Since the number is greatly reduced, not only the assembling property but also the layout flexibility is increased and the size can be reduced.

According to the fifth aspect of the present invention, in addition to the fourth aspect of the present invention, since the hologram element also has a built-in light source and its emission function, the optical axis of the light emitted from the light source can be adjusted. Since the adjustment is included, no new adjustment is required, and the time can be reduced.

According to the sixth aspect of the present invention, in the optical disk device of the fourth or fifth aspect, since one end of the optical fiber is integrated with the hologram element, the optical axis of the hologram element and the optical fiber can be adjusted. This eliminates the need for the hologram element, and the positioning accuracy of the hologram element may be low, so that the number of components can be reduced and the assembling work can be simplified, such as by directly soldering to the circuit board.

According to the seventh aspect of the present invention, in the optical disk device according to any one of the fourth to sixth aspects, a part of the light from the light source is reflected inside the hologram element to monitor the amount of light built in the hologram element. Since the light is incident on the light receiving element, it is possible to detect a monitor signal for controlling the light emission power of the light source without installing a new light receiving element and adjusting its position.

According to the eighth aspect of the present invention, in the optical disk device according to any one of the fourth to seventh aspects, since the other end of the optical fiber is detachably disposed, the defect of the hologram element can be improved. In addition, when the breakage occurs, the end of the optical fiber can be used as a cutout portion at the component replacement level.

According to the ninth aspect of the present invention, in the optical disk device according to any one of the first to eighth aspects, the light source or the light source driving circuit is disposed on the device fixing portion and is brought into contact with the heat radiating member to radiate heat. Therefore, it is possible to suppress an increase in the temperature of the light source itself or its light source driving circuit and the inside of the device, and to prevent performance degradation of the device due to temperature fluctuation. That is, by arranging the light source in the device fixing portion, it is necessary to install the light source near the light source, and the light source driving circuit or the light source itself that generates a large amount of heat can be brought into contact with a member having a high heat radiation effect, for example, an outer iron plate or the like. become.

According to the tenth aspect of the present invention, since a plurality of semiconductor lasers are used as the light source provided in the device fixing portion, a plurality of semiconductor lasers having different characteristics such as wavelength and power are mounted. Also, since the mounting parts and weight of the apparatus movable section do not change, the present invention can be applied to the above-described optical disk apparatus for various types of optical recording media.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an optical disk device showing a first embodiment of the present invention.

FIG. 2 is a schematic configuration diagram of an optical disk device showing a second embodiment of the present invention.

FIG. 3 is a schematic configuration diagram of an optical disc device showing a third embodiment of the present invention.

FIG. 4 is a schematic sectional view showing a configuration example of the hologram element.

FIG. 5 is a plan view of the inside of a hologram element shown in comparison with a conventional example.

FIG. 6 is a schematic configuration diagram near a light source of an optical disc device according to a fourth embodiment of the present invention.

FIG. 7 is a schematic configuration diagram of an optical disk device showing a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Device fixed part 2 Optical recording medium 3 Device movable part 8 Light source 8a, 8b Semiconductor laser 9 Light source drive circuit 10 Optical fiber 10a One end 10b Other end 16 Objective lens 17 Actuator 33 RF light receiving element 34 Optical fiber 34a One end 34b Other end 41 Hologram element 42 Optical fiber 42a One end 42b Other end 46 Light source 48 Light-quantity monitoring light-receiving element A to D Split light-receiving element

Claims (10)

[Claims] A light source for irradiating an optical recording medium disposed on a device fixing unit, an actuator including an objective lens for converging the irradiation light on the optical recording medium, and an actuator mounted on a device movable unit; The direction of each end is respectively positioned with respect to the light source and the actuator, and both ends thereof are disposed in the device fixing portion.Light emitted from the light source is incident from one end and the other end is emitted from the other end. An optical disk device comprising: an optical fiber that emits light toward an actuator. A light source for emitting light to the optical recording medium; an actuator including an objective lens for condensing the light on the optical recording medium; an actuator mounted on a movable portion of the device; An RF light receiving element for receiving an RF component in reflected light from the optical recording medium; and directions of respective ends are respectively positioned with respect to the actuator and the RF light receiving element, and these are positioned in the device fixing portion. An optical fiber provided with both ends of the optical recording medium, and reflected light from the optical recording medium being incident from one end via the actuator and emitting from the other end toward the RF light receiving element. 3. The optical disk device according to claim 1, wherein the optical fiber is detachably provided. A light source for emitting light to the optical recording medium; an actuator including an objective lens for condensing the light on the optical recording medium; A hologram element having a function of dividing the reflected light from the optical recording medium into a plurality of parts and condensing the reflected light on the built-in divided light-receiving elements, and the direction of each end is relative to the actuator and the hologram element. These two ends are disposed in the apparatus fixing portion being positioned respectively, and an optical fiber in which reflected light from the optical recording medium is incident from one end through the actuator and emitted from the other end toward the hologram element. An optical disc device comprising: 5. An actuator including an objective lens for converging irradiation light on an optical recording medium and mounted on a movable portion of the apparatus, a light source built-in and light emitted from the light source,
A hologram element disposed on a device fixing portion having a function of dividing the reflected light from the optical recording medium into a plurality of light beams and condensing the reflected light beams on the built-in divided light receiving elements; Both ends thereof are disposed in the device fixing portion, which are positioned with respect to the actuator and the hologram element, and light emitted from the light source is incident from the other end and emitted from the one end toward the actuator, An optical fiber device comprising: an optical fiber that receives reflected light from the optical recording medium from the one end via the actuator and emits the light from the other end toward the hologram element. 6. The optical disk device according to claim 4, wherein said one end of said optical fiber is integrated with said hologram element. 7. The hologram element has a function of reflecting a part of the light from the light source inside the element, and includes a light quantity monitoring light receiving element for controlling the light quantity of the light source for receiving the reflected light. Item 7. An optical disk device according to any one of Items 4 to 6. 8. The optical disk device according to claim 4, wherein the other end of the optical fiber is detachably provided. 9. The light source or the light source drive circuit for driving the light source provided in the device fixing portion is provided in direct or indirect contact with a heat radiating member. 8. The optical disk device according to any one of items 8 to 8. 10. The optical disk device according to claim 1, wherein the light source provided in the device fixing unit includes a plurality of semiconductor lasers.