JPH11110789A - Optical head device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce parts and assembly costs by commonly using an adhesive for fixing a laser chip at a determined position on a sub mount for transferring heat being generated by the laser chip to a heat sink and an airtight material for sealing the cutting surface of the laser chip. SOLUTION: In the manufacturing process of a laser chip 16, metallized surfaces 16c and 16d are generated at a part with a wide area where a semiconductor layer is laminated and a semi-transparent film is coated on a light emission surface 16a and a light emission surface rear surface 16b. Then, both of them are machined airtightly, but cutting surfaces 16e and 16f that appear as a result of cutting need to be protected from external air by a sealing agent or the like. In the assembly of a laser unit, the laser chip 16 adheres the metallized surface 16d to a determined position on the sub mount for fixing. At this time, an adhesive is applied to the cutting surfaces 16e and 16f at both sides, thus joining with the sub mount and at the same time sealing the cutting surfaces 16e and 16f.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical head device for reproducing information from an optical disk as a recording medium, and more particularly to an improvement in a laser unit for providing a laser beam.

[0002]

2. Description of the Related Art An optical disk device includes an optical head device having an objective lens for irradiating a recording surface of an optical disk as a recording medium with a light beam having a cross-sectional beam diameter set to a predetermined size. By irradiating the beam, reflected light corresponding to the information recorded on the optical disk is taken out to reproduce the information.

The above-described optical head device has a semiconductor laser device (hereinafter simply referred to as a laser device) as a light source for generating a light beam and a light beam radiated from the laser device on a recording surface of an optical disk as a recording medium. An objective lens for converging and extracting a reflected light beam reflected by the recording surface, a photodetector for photoelectrically converting the reflected light beam extracted by the objective lens and outputting a reproduction signal corresponding to information recorded on the optical disc; It is formed by a plurality of optical members or the like forming an optical path of a light beam between the respective elements.

As shown in FIG. 7, the laser device has a laser unit 102 formed on a laser unit base (stem) 101. On the side of the stem 101 where the laser unit 102 is formed, a cap 105 provided with a glass window 104 capable of emitting a laser beam L emitted from the laser chip 103 of the laser unit 102 to the outside is provided with an airtight structure. It is fixed to. The laser unit 102 is connected to a driving circuit (not shown) by a plurality of lead pins 106 protruding from a side of the stem 101 opposite to the side on which the laser unit 102 is formed via a circuit portion (not shown) formed on the stem 101. Connected to.

[0005]

However, as is apparent from FIG. 7, the laser element is required to be airtight.
Since an airtight structure is required, for example, the glass window 104
, And the cap 105 and the stem 101 must be sealed with a sealing agent (not shown).

Further, as shown in FIG. 8, for example, even when the laser unit 112 is formed in a box shape, a glass plate 114 is required for airtightness. Further, in the structure shown in FIG. 8, since the laser beam L emitted from the laser chip 113 is emitted in parallel to the glass plate 114, a cube mirror for directing the laser beam L to the glass plate 114 117 is also required. In addition,
Since the glass plate 114 must be connected to the laser unit 112 in an airtight structure, the hermetic treatment with a sealing agent (not shown) is a process that cannot be reduced as shown in FIG. When the structure shown in FIG. 8 is used, the component cost can be reduced as compared with the structure using the cap 105, but the structure shown in FIG. 7 is advantageous in terms of heat dissipation. There is a problem that the wavelength of the laser beam L generated from the laser chip 113 tends to fluctuate.

As described above, regardless of the manufacturing method and process, there is a problem that the cost of parts and assembly increases because the manufacturing process is complicated and the number of parts cannot be reduced. This increases the cost of the entire optical disc device.

It is an object of the present invention to provide a laser light emitting device which can reduce costs and steps when manufacturing a laser light emitting device applied to an optical head device for reproducing information from an optical disk.

[0009]

SUMMARY OF THE INVENTION The present invention has been made based on the above-mentioned problems, and converges light from a light source on a recording surface of a recording medium and transmits light reflected on the recording surface in a substantially parallel manner. Light collecting means for converting the light into substantially parallel light, the direction changing means for separating the substantially parallel light from the light collecting means by the light collecting means, and the light separated from the light toward the light collecting means by the direction changing means. An optical head device comprising: a light-condensing means for detecting a position of the light-condensing means and a recording surface of a recording medium at an appropriate value by photoelectrically converting the light; A light-emitting surface that emits light of a predetermined wavelength and that is held in a heat-conducting manner with an auxiliary substrate with respect to a heat sink provided on a substrate that supports at least the detection unit, and a light-emitting surface that faces the light-emitting surface Rear surface, light exit surface and Two metallized surfaces that are orthogonal to each of the rear surfaces of the light emitting surfaces and are arranged substantially parallel to each other; and that are substantially cubic or thick by being orthogonal to each of the light emitting surface and the rear surfaces of the light emitting surfaces and each of the two metallized surfaces. The present invention provides an optical head device characterized by having two end faces constituting a plate-like body having a certain thickness, and being fixed at a predetermined position on the auxiliary substrate by a sealant for protecting the two end faces.

Further, according to the present invention, a light emitting surface for emitting light, a rear surface of the light emitting surface facing the light emitting surface, and a light emitting surface and a rear surface of the light emitting surface are arranged orthogonal to each other and substantially parallel to each other. Two metallized surfaces to be formed, and two end surfaces which form a substantially cubic or thick plate-like body by being orthogonal to each of the light emitting surface and the rear surface of the light emitting surface and each of the two metallized surfaces. A light source that outputs light of a predetermined wavelength in a direction orthogonal to the light exit surface, and condenses light from the light source onto a recording surface of a recording medium, and converts light reflected by the recording surface into substantially parallel light. And a light condensing means for converting the light. In the optical head device, the light source can be arranged such that the light exit surface can enter the light with respect to the light condensing means by a hermetic agent that hermetically seals the two end faces. Make sure that the There is provided an optical head apparatus according to claim.

Further, the present invention provides a light emitting surface extending in a first direction for emitting light, a rear surface of the light emitting surface facing the light emitting surface, and a second light emitting surface orthogonal to the first direction. Two metallized surfaces extending in the direction of. And the light exit surface defined along a third direction orthogonal to each of the first and third directions. A light emitting surface having a predetermined wavelength along the first direction, the light emitting surface having two end surfaces that form a substantially cubic or thick plate-like body together with each of the two metallized surfaces. A light source, and a light condensing unit that condenses light from the light source on a recording surface of a recording medium and converts light reflected on the recording surface into substantially parallel light, wherein the light source is The light emitting surface is sealed by an airtight agent for hermetically sealing the two end surfaces. There is provided an optical head device, characterized in that it is entering securing the light source to the array of auxiliary substrate light to serial condensing means.

[0012]

Embodiments of the present invention will be described below in detail with reference to the drawings. As shown in FIG.
The optical head device 1 is disposed so as to be movable between a main unit 2 disposed substantially parallel to a recording surface (not shown) of the optical disk and a spindle motor (not shown) that rotates the optical disk at a predetermined speed. Has an actuator unit 3 for irradiating a laser beam from the main unit 2 toward a recording surface (not shown).

The main unit 2 includes a laser unit 12 for emitting a laser beam L whose polarization plane is defined in a predetermined direction, and an actuator unit 3 (recording surface of an optical disk (not shown)). ), A part of which is reflected toward an APC photodetector, which will be described in detail later with reference to FIG. 5, and furthermore, the elliptic correction for adjusting the cross-sectional shape of the laser beam L emitted from the laser unit 12 into a substantially circular shape. The laser beam L passed through the prism 5 and the elliptic correction prism 5 is guided toward the actuator unit 3, and the reflected laser beam Lr reflected on the recording surface of the optical disk (not shown) is guided in a predetermined direction. The polarizing hologram element 6 for giving predetermined optical characteristics to the beam Lr, A collimating lens 7 that collimates the laser beam L passing through the gram element 6 and a polarization direction of the laser beam L passing through the collimating lens 7 and irradiating the recording surface of the optical disk and a reflected laser reflected from the recording surface of the optical disk The direction of polarization of the beam is 90
The λ / 4 plates 8 that rotate by ° are arranged in order. In addition,
The laser beam L is reflected on the recording surface of the optical disc by the polarizing hologram element 6, and the direction of polarization is rotated by 90 ° compared to the state where the laser unit 12 is emitted from the circularly polarized light by the λ / 4 plate 8. An optical characteristic is provided that allows only the reflected laser beam from the optical disc that has been transmitted to pass through and diffracts the beam by a predetermined angle. Also,
As described above, the polarizing hologram element 6, the collimating lens 7, and the λ / 4 plate 8 are connected to the housing 10 of the main unit 2.
, Are arranged integrally.

The housing 10 is formed of, for example, aluminum, which has a high thermal conductivity (that is, has a high heat dissipation) and a small change in shape with a change in temperature. At a predetermined position of the housing 10, a laser unit 12 formed on a stem (that is, a unit base) 11 and a photodetector unit 13 having a plurality of light receiving regions described in detail later with reference to FIG. I have.
Each of the photodetector unit 13 and the laser unit 12 is heated by a cubic or plate-shaped heat sink 14 having a predetermined thickness and extending over substantially the entire area of the first surface 11a of the stem 11 in the surface direction. It is fixed to be conductive. It goes without saying that the photodetector unit 13 shown in FIG. 5 may be formed separately from the laser unit 12.

As shown in FIG. 2, the laser unit 12 includes a submount 15 which is in close contact with a laser chip mounting surface 14a of a heat sink 14 orthogonal to the first surface 11a of the stem 11 so as to be able to conduct heat, and a submount 15 The laser chip 16 is fixed at a predetermined position. In the area of the heat sink 14 where the submount 15 is in close contact, the side of the submount 15 and the submount 1
For example, the laser chip 16 and the respective light receiving areas of the photodetector unit 13 or the laser unit 12 of the stem 11 described below are moved in a direction that does not prevent the laser beam emitted from the laser chip 16 adhered to the laser beam 5 from being emitted to the outside. Relay members 17 used for electrical connection with a plurality of lead pins (not shown) arranged on a surface opposite to the side to be in close contact are arranged.

The laser chip 16 is, as shown in FIG.
A light emitting surface 16a, which is formed in a substantially cubic or thick plate shape, extends in the first direction, and is coated with a translucent film (protective film) (not shown), and a light emitting surface facing the light emitting surface 16a. Rear surface 16b, light exit surface 16
a and a first surface orthogonal to the rear surface 16b of the light exit surface.
And a pair of surfaces arranged substantially in parallel to each other and forming metallized surfaces 16c and 16d forming a large area portion of the laser chip 16, and orthogonal to each of the first and second directions. It has cut surfaces 16e and 16f along the third direction.

By the way, many of the laser chips 16 are formed by laminating a plurality of semiconductor layers (not described in detail), and then metallized on each surface in order to prevent oxidation of a large area portion and to secure electrical conduction. Further, the light emitting surface 16a and the rear surface 16b of the light emitting surface are coated with the above-described translucent film, and thereafter, are cut out to have a predetermined width and manufactured. For this reason, the metallized surfaces 16c and 16d, the light exit surface 16a, and the rear surface 16b of the light exit surface are substantially airtightly processed.

From this, air-tight processing, that is, air-tight processing with a sealant is performed by cutting the cut surfaces 16e and 16f described above.
The main purpose is to protect from outside air. The light exit surface 16a, the rear surface 16b of the light exit surface, and the two metallized surfaces 16c and 16d have a structure without any other protective material.
Therefore, when manufacturing the laser unit 12 shown in FIG.
When fixing the fixing surfaces, the fixing adhesive and the cut surfaces 16e, 16
By also using the sealing agent of f, the sealing step required in the conventional manufacturing method can be omitted.

FIG. 4 shows the laser unit 12 shown in FIG.
FIG. 3 is a schematic cross-sectional view showing a connection state between a submount 15 and a laser chip 16 and a sealing agent 18 used for hermetically sealing cut surfaces 16e and 16f of the laser chip 16 when viewed from a cross-sectional direction.

The submount 15 and the heat sink 1
A lubricant layer 19 typified by, for example, a silicon paste for enhancing a heat radiation effect may be formed between the laser chip mounting surface 14a and the laser chip mounting surface 14a.

As is apparent from FIGS. 2 to 4, the laser chip 16 is disposed on the laser unit 12 such that the light emitting surface 16a is exposed in a direction orthogonal to a wide area of the stem 11. However, it does not require a hermetic cap or package structure as found in conventional laser devices.

FIG. 5 is a schematic diagram showing the shape and arrangement of a plurality of light receiving areas on the light receiving surface of the photodetector unit 13. As shown in FIG. Note that the photodetector unit 13 is located at a predetermined distance g from the submount 15 in the large area portion 14b of the heat sink 14 that has been in close contact with the stem 11 already described with reference to FIG.

As shown in FIG. 5, the photodetector unit 13 has a light receiving surface 21 on which a plurality of light receiving areas are formed. The light receiving surface 21 is, as schematically shown in FIG.
Of the reflected laser beam Lr from the optical disk having a predetermined optical characteristic after passing through the axis, through which one of the laser beam used for detecting a track shift or the laser beam used for detecting a focus shift passes Are arranged so as to be orthogonal to.

On the light receiving surface 21, the laser unit 12
The position relatively close to the axis through which the principal ray (center of light intensity) of the laser beam L traveling from the laser chip 16 toward the optical disk passes is determined by the information reflected on the recording surface of the optical disk and recorded on the optical disk. Receives the reflected laser beam Lr whose light intensity has been changed, converts the reflected laser beam into an electric signal corresponding to the light intensity, and sets the distance between the recording surface of the optical disc and the objective lens described below disposed on the actuator unit 3 as: First to fourth light detection areas 22a to 22 that output a focus shift signal for focus control to match the distance at which the laser beam L is converged depending on the convergence given to the laser beam L by the objective lens.
Fifth and sixth light detection areas 23a for outputting a track shift signal for track control to make d and the center of the track on the recording surface of the optical disc coincide with the center of the light intensity of the laser beam L passed through the objective lens. , 23b are formed.

The first axis from the axis through which the principal ray of the laser beam L traveling from the laser chip 16 to the optical disk passes.
Or at a position further than the fourth detection areas 22a to 22d and the fifth and sixth detection areas 23a and 23b,
The reflection hologram element 5 receives the laser beam L reflected immediately after passing through the polarizer 4 and converts it into an electric signal corresponding to the light intensity, and converts the light intensity of the laser beam L emitted from the laser chip 16 An APC light receiving area 24 for auto power control (hereinafter abbreviated as APC) for outputting a monitor signal is formed.

As shown, the first to fourth light detection areas 22a to 22d for outputting the focus shift signal are rectangular and adjacent to each other by two orthogonal dividing lines, and 6, the reflected laser beam L shifted to a position away from the axis through which the principal ray of the laser beam L from the laser chip 16 passes by a predetermined distance.
When the distance between the objective lens and the optical disc is given convergence by the objective lens and the focal positions of the laser beam L converged at a predetermined distance do not match, the outputs of the four detection areas are appropriately adjusted. When the differential output combined with “1” is “0” or an output different from the predetermined value, a focus shift is indicated.

The fifth and sixth light detection areas 23a and 23b for outputting the track shift signal extend along one of the first to fourth detection areas used for outputting the focus shift signal. Has a detection structure capable of detecting the position only in one direction adjacent to the divided line, and the output of one detection area is reduced by projecting a shadow of a track (not shown) formed on the recording surface of the optical disc. This indicates a track shift.

The APC light receiving area 24 has a larger light receiving area than other detection areas for the purpose of detecting a laser beam L having a lower light intensity than the laser beam L directed to the optical disk reflected by the reflection type hologram element 5. It has an area and detects a slight change in light intensity of the laser beam Lr reflected by the reflection type hologram element 5.

The actuator unit 3 has a carriage 30 for moving an objective lens, which will be described later, along a recording surface of an optical disk (not shown) in a direction crossing a track (not shown) formed on the recording surface.

The carriage 30 includes a pair of radial drive coils 31, 31 and a pair of guide rails 32, 32, which form a part of a linear motor formed integrally with the carriage 30.
Is moved in the radial direction of the optical disk.

The carriage 30 is provided with a rising mirror 33 that bends a laser beam L emitted from the laser unit 4 and guided substantially parallel to the recording surface of the optical disk so as to be incident on an objective lens described later. .

The laser beam L reflected by the rising mirror 33 is guided in the direction of the laser beam L reflected by the rising mirror 33, ie, between the rising mirror 33 and the optical disk. An objective lens 34 for forming an image on a predetermined depth of a recording surface of the optical disc, that is, a recording layer (not shown), and transmitting the reflected laser beam Lr reflected by the recording layer of the optical disc toward the laser unit 4 is arranged.

The objective lens 34 is held by a lens holder 35 holding the objective lens 34, and a support member 36 fixed at a predetermined position of the carriage 30 and a lens holder 35
Of the lens holder 35 by the spring 36a passed between
Is supported so as to be movable in a direction perpendicular to the recording surface of the optical disk, and is held so as to be movable in a direction perpendicular to the recording surface of the optical disk.

The laser beam L guided around the lens holder 35 and guided by the rising mirror 33 and the rising mirror 3
At a position where the reflected laser beam Lr returned to the optical disk 3 is not interrupted, the lens holder 35 is provided with a track (not shown) parallel to the recording surface of the optical disc and formed concentrically or spirally on the recording surface. A track control coil 37 for moving in a direction (track control direction) crossing a guide groove defining a layer, and a focus control coil for moving the lens holder 35 in a direction (focus control direction) orthogonal to the recording surface of the optical disc. 38 and a fixed magnet 39 for converting a force generated by supplying a current to each coil to a driving force for moving the objective lens 34.

FIG. 6 shows an example of a control section for controlling the optical head device shown in FIG. As shown in FIG. 6, the optical head device 1 is connected to a host computer (not shown), extracts data recorded on a predetermined track of an optical disk (not shown), and transmits the data to the host computer based on an instruction from the host computer. And a control unit 9 for performing the operation.

The control unit 9 generates a laser beam L having a predetermined light intensity from the laser chip 16 of the laser unit 12 based on an instruction from a host computer (not shown), and controls the objective lens 34 mounted on the actuator unit 3 to operate. And a main control circuit 50 for controlling the position of the objective lens 34 so as to have a predetermined positional relationship with respect to the optical disk, and controlling the optical head device 1 to reproduce information recorded on the optical disk.

The main control circuit 50 is connected to a linear motor control circuit 51 for moving the lens holder 35, that is, the objective lens 34, in parallel with the recording surface of the optical disk.
The linear motor control circuit 51 moves the actuator unit 3 to the vicinity of the target track on the recording surface of the optical disk based on the position signal of the target track supplied from the main control circuit 50.

The main control circuit 50 is connected to a laser drive circuit 52 for emitting a laser beam having a predetermined intensity from the laser chip 16. Laser drive circuit 52
Is the AP of the light receiving surface 21 of the photodetector unit 13
Based on the output from the C light receiving area 24, the magnitude of the drive current supplied to the laser chip 16 is controlled so that the laser chip 16 can output a laser beam L having a constant intensity.

Further, the main control circuit 50 includes an objective lens 34, that is, a lens holder 35, a focal length of the objective lens 34 and a recording surface (not shown) of the optical disk.
A focus control circuit 53 for moving the lens holder 35 in a direction perpendicular to the recording surface of the optical disk is connected so as to match the distance between the lens holder 35 and the lens holder 35.

The focus control circuit 53 controls the focus control coil 38 based on the focus shift signals output from the first to fourth four detection areas 22a to 22d.
Is supplied with a current of a predetermined polarity (direction).

The main control circuit 50 also includes first to fourth
An information signal processing circuit 54 for extracting data recorded on the optical disk based on all outputs output from the detection areas 22a to 22d is connected.

Further, the main control circuit 50 moves the objective lens 34 in a direction perpendicular to a track (not shown) based on the track shift signal obtained from the outputs of the fifth and sixth detection areas 23a and 23b. A track control circuit 55 for supplying a current of a predetermined polarity (direction) is connected to the track control coil 37.

The main control circuit 50 specifies the magnitude of the output light intensity emitted from the laser chip 16 with reference to the output of the APC light receiving area 24, and
2 is connected to the APC circuit 56 that feeds back to the APC circuit 2.

Next, the operation of the optical head device 1 will be described with reference to FIG. When a power switch (not shown) is turned on, an initial program is read from a memory (not shown) under the control of the main control circuit 50, and the actuator unit 3 is moved to a predetermined position. Specifically, under the control of the linear motor control circuit 51, the actuator unit 3 is moved to a predetermined position, for example, a calibration area of a lead-in area (not shown) of a recording surface (not shown) of the optical disk.

Subsequently, the laser chip 16 emits preliminary light under the control of the laser drive circuit 52. Based on the reflected laser beam Lr obtained by this preliminary light emission, the distance between the objective lens 34 and the optical disc and the
4, the difference between the distance between the convergence point at which the laser beam L given the convergence giving the minimum beam waist and the objective lens 34, that is, the focus shift is detected, and the drive current corresponding to the focus shift is detected by the focus coil 38. And the objective lens 34 is focus-locked.

Hereinafter, under the control of the main control circuit 50, a laser drive current of a predetermined magnitude is supplied to the laser chip 16 from the laser drive circuit 52, and a laser beam L of a predetermined light intensity is emitted from the laser chip 16. .

The laser beam L emitted from the laser chip 16 is partially reflected by the elliptic correction prism 5 toward the APC light receiving area 24 of the photodetector unit 13, and the rest is directed to the polarizing hologram element 6.

The laser beam L that has reached the polarizing hologram 6 is collimated by the collimating lens 7 and
The direction of deflection is changed from linearly polarized light in a predetermined direction to circularly polarized light by the plate 8 and directed to the rising mirror 33.

The circularly polarized laser beam L that has reached the rising mirror 33 is reflected by the rising mirror 33 and is incident on the objective lens 34. The objective lens 34 converges on the recording surface of the optical disk in a predetermined sectional shape. Is done.

The circularly polarized laser beam L converged on the recording surface of the optical disk is reflected with its light intensity changed according to the information recorded on the recording surface, that is, the presence or absence of a recording mark (pit). Is returned to. The light receiving surface of the photodetector unit 13 described with reference to FIG. 3 according to the distance between the position of the objective lens 34 and the optical disk and the deviation between the center of the laser beam L passing through the objective lens 34 and the track center. Since the output signals output by the respective light receiving areas 21 are changed, the lens holder 35, that is, the objective lens 34 is moved in the focus control direction and the track control direction based on the output from the respective light receiving areas. Track recording marks (pit rows) are accurately tracked.

The reflected laser beam Lr from the recording surface of the optical disk returned to the objective lens 34 is returned to a parallel laser beam again by the objective lens 34,
3 is reflected toward the λ / 4 plate 8.

The reflected laser beam L returned to the λ / 4 plate 8
r is converted from circularly polarized light into linearly polarized light whose direction of polarization is rotated by 90 ° as compared with the direction of polarization when passing through the polarizing hologram 6, and given a predetermined convergence by the lens 7, Hologram element 6.

The reflected laser beam Lr arriving at the polarizing hologram element 6 is diffracted by a diffraction hologram pattern (not shown) provided on the polarizing hologram 6 in advance, and the first to fourth reflected light beams are formed on the light receiving surface 21 of the photodetector unit 13. Are shifted by a predetermined distance toward each of the detection regions 22a to 22d and the fifth and sixth detection regions 23a and 23b, and are imaged on the respective light receiving regions.

The laser beam Lr guided to the first to fourth detection areas 22a is converted by the same light detection area into an electric signal having a magnitude corresponding to the light intensity, and is used to generate a focus error signal and a reproduction signal. Used. Note that any of various well-known detection methods can be used to detect the focus shift based on the focus error signal, and a detailed description thereof will be omitted. In addition, since a number of well-known methods can be applied to the generation of the reproduction signal, detailed description is omitted here.

Subsequently, based on the focus error signal, the lens holder 35 is moved in a direction orthogonal to the recording surface of the optical disc, and the focus of the objective lens 34 is controlled. The reflected laser beam Lr guided to the fifth and sixth light detection areas 23a and 23b is
It is converted into an electric signal having a magnitude corresponding to the light intensity and used for generating a tracker signal. Note that any of various well-known detection methods can be used to detect a track shift based on a track error signal, and a detailed description thereof will be omitted.

In tracking, a track control signal which is a current in a predetermined direction corresponding to a track error signal from the track control circuit 75 is supplied to the track control coils 37, 37, so that the lens holder 35
The objective lens 34 is reciprocated in a direction orthogonal to a track (not shown) on the recording surface of the optical disk, that is, in a radial direction of the optical disk.

As described above, the outputs of the first to fourth detection areas 22a to 22d are output by the information reproducing circuit 54 to the information length (size) of the information recorded on the optical disc and the information length of the information. The number and the like are read out and reported to a host computer (not shown) via the main control circuit 50.

[0058]

As described above, in the optical head device according to the present invention, the laser chip for emitting a laser beam is generated in a heat sink for radiating heat in a laser unit integrally formed with the photodetector. For the sub-mount that transmits heat, the light emitting surface of the laser chip and the light emitting surface rear surface facing the light emitting surface, and the light emitting surface and the light emitting surface rear surface that are connected to each other are connected to each other. It is secured by an airtight agent provided on a cut surface orthogonal to each of the metallized surfaces. Here, by using both the adhesive for fixing the laser chip at a predetermined position of the submount and the airtight agent for sealing the cut surface, the sealing step required in the conventional light emitting element manufacturing method can be omitted. .

In the laser chip manufactured by this method, after laminating a plurality of semiconductor layers (not described in detail), each surface is formed to prevent oxidation of a large area portion and to secure electrical conduction. The metallized surface is further coated with a translucent film on the light emitting surface and the rear surface of the light emitting surface, and then cut out to a predetermined width to be manufactured, whereby the two metallized surfaces, the light emitting surface, and the light emitting surface are formed. The rear surface will be substantially airtight. Therefore, by using an airtight agent when fixing the laser chip to the submount, all surfaces of the laser chip formed in a cubic or thick plate shape are substantially airtightly processed, which is necessary for conventional light emitting devices. This eliminates the need for the hermetic glass or hermetic package. As a result, assembly costs and component costs are reduced.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing an optical head device using a laser unit to which an embodiment of the present invention is applied.

FIG. 2 is a schematic diagram showing a laser unit used in the optical head device shown in FIG.

FIG. 3 is a schematic diagram illustrating a laser chip used in the laser unit shown in FIG. 2;

4 is a schematic diagram illustrating a positional relationship between a laser chip and a sealant when the laser unit illustrated in FIG. 2 is configured using the laser chip illustrated in FIG. 3;

FIG. 5 is a schematic diagram showing the shape and arrangement of a light receiving area on a light receiving surface of a photo detector unit integrated with the laser unit shown in FIG. 2;

FIG. 6 is a schematic block diagram showing an example of a control unit that controls the optical head device shown in FIG.

FIG. 7 is a schematic view showing an example of a conventionally used light emitting element.

FIG. 8 is a schematic view showing an example of a light emitting element conventionally used.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Optical head device, 2 ... Body unit, 3 ... Actuator unit, 5 ... Elliptical correction prism, 6 ... Polarization hologram, 7 ... Collimator lens, 8 ... λ / 4 plate, 9 ... Control part, 10 ... Housing, 11 ... Stem, 12 ... Laser unit, 13 ... Photodetector unit, 14 ... Heat sink, 14a ... Laser chip mounting surface, 15 ... Submount, 16 ... Laser chip, 17 ... Relay member, 18 ... Sealant, 21 ... Light receiving surface, 22a ... first light detection area, 22b ... second light detection area, 22c ... third light detection area, 22d ... fourth light detection area, 23a ... fifth light detection area, 23b ... sixth light Detection area, 24: APC light receiving area, 30: Carriage, 31: Radial drive coil, 32: Guide rail, 33: Start-up -, 34 ... objective lens, 35 ... lens holder, 36 ... support member, 37 ... track control coil, 38 ... focus control coil, 39 ... fixed magnet, 50 ... main control circuit, 51 ... linear motor control circuit, 52 ... laser Drive circuit, 53: Focus control circuit, 54: Information signal processing circuit, 55: Track control circuit, 56: APC circuit

Claims (7)

[Claims] A light condensing means for condensing light from a light source on a recording surface of a recording medium, and converting light reflected on the recording surface into substantially parallel light; Direction changing means for separating the light from the light collecting means, and the light directed to the light collecting means and the light separated by the direction changing means are photoelectrically converted to change the positional relationship between the light collecting means and the recording surface of the recording medium. An optical head device comprising: a light-condensing means position detecting means for setting the light-condensing means at an appropriate value; wherein the light source includes an auxiliary substrate with respect to a heat sink provided on a substrate supporting at least the light-condensing means position detecting means. A light-emitting surface that is held so as to be thermally conductive and emits light of a predetermined wavelength, a light-emitting surface rear surface facing the light-emitting surface, and a light-emitting surface and a light-emitting surface rear surface that are orthogonal to each other and substantially perpendicular to each other. Arranged in parallel It has two metallized surfaces, two light emitting surfaces and two end surfaces that are substantially orthogonal to each of the light emitting surface rear surface and the two metallized surfaces to form a generally cubic or thick plate-like body. An optical head device, wherein the optical head device is fixed at a predetermined position on the auxiliary substrate by a sealant protecting the two end surfaces. 2. The optical head device according to claim 1, wherein the sealing agent also functions as a sealing agent for sealing the two end faces of the light source. 3. The optical head device according to claim 1, wherein the sealant also serves as an adhesive for fixing the light source to the auxiliary substrate. 4. A light-emitting surface for emitting light, a rear surface of the light-emitting surface facing the light-emitting surface, and two surfaces orthogonal to each of the light-emitting surface and the rear surface of the light-emitting surface and arranged substantially parallel to each other. Metallization surface, and a light exit surface and a rear surface of the light exit surface, and two end surfaces that form a substantially cubic or thick plate-like body by being orthogonal to each of the two metallized surfaces. A light source that outputs light in a direction orthogonal to the light exit surface; a light source that collects light from the light source on a recording surface of a recording medium and converts light reflected on the recording surface into substantially parallel light. Means, wherein the light source is fixed to an auxiliary substrate on which the light source can be arranged so that the light exit surface can enter the light into the light condensing means by a hermetic agent for hermetically sealing the two end faces. Light De devices. 5. The method according to claim 1, wherein the two end faces are used when manufacturing the light source.
5. The optical head device according to claim 4, wherein the light emitting surface is orthogonal to a direction in which a plurality of semiconductor layers are stacked and each of the light emitting surfaces. 6. A light emitting surface extending in a first direction for emitting light, a rear surface of the light emitting surface facing the light emitting surface, and extending in a second direction orthogonal to the first direction. The light-emitting surface, the light-emitting surface defined along two metallized surfaces that are emitted and arranged substantially parallel to each other, and a third direction orthogonal to each of the first and third directions. Back side,
A light source that has two end surfaces that form a substantially cubic or thick plate with each of the two metallized surfaces, and outputs light of a predetermined wavelength along the first direction; A light collecting means for condensing light on a recording surface of a recording medium and converting light reflected on the recording surface into substantially parallel light, wherein the light source hermetically seals the two end faces. An optical head device, wherein the light emitting surface is fixed to an auxiliary substrate on which the light sources can be arranged so that light can enter the light condensing means by an airtight agent. 7. The method according to claim 7, wherein the two end faces are used when manufacturing the light source.
7. The optical head device according to claim 6, wherein the light emitting surface is orthogonal to a direction in which a plurality of semiconductor layers are stacked and each of the light emitting surfaces.