JPH10149557A - Light emitting and receiving elements for optical pickup and cover therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the number of parts and an assembling cost by integrally composing the optical element of an optical pickup, an astigmatic aberration compensating plate an anamorphic optical system, a collimator lens or a polarizing hologram element, etc. SOLUTION: In a light emitting and receiving elements 13 for an optical pickup, the upper surfaces of the semiconductor substrate 13a, 13b, the light emitting and receiving elements 13, a microprism 13d, a first and a second photodetectors 13e, 13f are formed by covering them. The light emitting and receiving elements 13 is composed so that an astigmatic compensating plate 14b whose tilt angle is adjustable is integrally provided with a cover 14 on the surface of the cover 14 through which a laser beam transmitted from the light emitting and receiving elements 13. Consequently, since the astigmatic compensating plate 14b and a collimator lens, etc., are integrally formed on the surface through which a light beam from the light emitting and receiving elements 13, the assembling of the respective optical elements is facilitated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light emitting / receiving element for an optical pickup of a recording / reproducing optical disk apparatus such as a mini disk (MD) and a compact disk (CD), and a cover thereof.

[0002]

2. Description of the Related Art Conventionally, an optical pickup for a compact disk is constructed as shown in FIG. In FIG. 10, an optical pickup 1 includes an objective lens 2, a light emitting / receiving element 3 fixedly arranged on a base (not shown), and an optical system 4.

[0003] The optical pickup 1 converts the laser beam emitted from the light emitting / receiving element 3 through the optical system 4 and the objective lens 2 to the objective lens 2 when the objective lens 2 is moved in the focusing direction and the tracking direction. The laser light (return light) from the signal recording surface of the optical disk 5 is converged and focused on a certain point on the signal recording surface of the optical disk 5 that is driven to rotate upward, and the light emitting / receiving element is transmitted through the objective lens 2 and the optical system 4. 3 is incident.

The optical system 4 guides the laser beam emitted from the light emitting / receiving element 3 to the objective lens 2 and guides the return light from the optical disk 5 from the objective lens 2 to the light emitting / receiving element 3. In the case shown, two mirrors 4 for bending the optical path are used.
a, 4b. The objective lens 2 is moved and adjusted in the focusing direction and the tracking direction by a biaxial actuator (not shown),
The laser light emitted from the light emitting / receiving element 3 is converged and focused on the signal recording surface of the optical disk 5 via the mirrors 4 a and 4 b of the optical system 4 and the objective lens 2. The return light from the signal recording surface of the optical disk 5 is
And the light receiving / emitting element 3 via the mirrors 4a and 4b of the optical system.
Is incident on.

As shown in FIGS. 11 and 12, a second semiconductor substrate 3b for light output is mounted on a first semiconductor substrate 3a.
The semiconductor laser device 3c as a light emitting device is mounted on the substrate b. On the first semiconductor substrate 3a in front of the semiconductor laser element 3c, a trapezoidal microprism 3d is provided.
The semiconductor laser device 3c is set with its inclined surface as the semi-transmissive surface facing the semiconductor laser element 3c. Further, the light emitting / receiving element 3 is housed in a rectangular parallelepiped case 6 having an open upper end, and the upper end of the case 6 is closed by a glass plate 7.

As a result, the light beam emitted from the semiconductor laser element 3c along the surface of the second semiconductor substrate 3b is reflected by the inclined surface of the microprism 3d, travels upward, and passes through the glass plate 7 The light is transmitted and travels toward the mirror 4a of the optical system 4. Then, the light beam reflected by the mirror 4a is further reflected by the mirror 4b of the optical system 4, and then passes through the objective lens 2.
The light is converged on the signal recording surface of the optical disk 5. Optical disk 5
Return light from the signal recording surface of the optical system 4 again passes through the objective lens 2, the mirrors 4 b and 4 a of the optical system 4, and
, The light enters the microprism 3d from the inclined surface of the microprism 3d, and reaches the bottom surface of the microprism 3d. The return light that has reached the bottom surface of the microprism 3d partially transmits through the bottom surface, and is partially reflected by the bottom surface, and travels toward the top surface of the microprism 3d. Here, the first photodetector 3e is formed on the first semiconductor substrate 3a below the return light incident position of the microprism 3d.

The return light reflected on the bottom surface is reflected on the top surface of the microprism 3d, and is incident on the bottom surface of the microprism 3d again. A second photodetector 3f is formed on the first semiconductor substrate 3a below the bottom portion of the microprism 3d where the return light reflected by the upper surface of the microprism 3d enters.

The first photodetector 3e and the second photodetector 3f are each divided into a plurality of sensor blocks, and the detection signals of each sensor block are output independently. I have. The second semiconductor substrate 3b
Above, on the side opposite to the emission side of the semiconductor laser element 3c,
A third photodetector 3g is provided. The third light detector 3g is for monitoring the light emission intensity of the semiconductor laser device 3c.

Optical pickup 1 constructed as described above.
According to the method, the laser light emitted from the semiconductor laser element 3c of the light receiving / emitting element 3 enters the inclined surface of the microprism 3d and is reflected by the inclined surface. Micro prism 3
The laser beam reflected by the inclined surface d is focused on a point on the signal recording surface of the optical disk 5 at a desired track position via the mirrors 4a and 4b of the optical system 4 and the objective lens 2. The return light from the optical disk 5 again enters the inclined surface of the microprism 3d of the light emitting / receiving element 3 via the objective lens 2 and the mirrors 4b and 4a of the optical system 4, and passes through the inclined surface. Proceed into the microprism 3d.

The return light that has entered the microprism 3d reaches the bottom surface of the microprism 3d. The return light incident on the bottom surface is partially transmitted and partially reflected toward the upper surface of the microprism 3d. The return light passing through the bottom surface is incident on the first photodetector 3e, while the return light reflected on the bottom surface is reflected by the micro prism 3d.
Is reflected by the upper surface of the micro prism 3d, passes through the bottom surface of the microprism 3d, and enters the second photodetector 3f.

As described above, the returning light is transmitted to the first photodetector 3e.
And the light enters the second photodetector 3f.
And 3f, based on the detection signals from the respective sensor blocks, a reproduction signal or a so-called differential three-division method (D-3)
By the DF method, a focus signal is detected, and a tracking error is detected based on a difference between detection signals of the respective sensor units of the first photodetector 3e.

[0012]

However, FIG.
In the optical pickup 1 for a compact disk shown in FIG. 1, the mirror 4 of the optical system 4 is used to minimize the thickness of the entire optical pickup 1, that is, the thickness from the lower surface of the optical disk 5 to the lowermost part of the optical pickup 1.
The optical path is bent by a and 4b. For this reason, the number of parts increases, and each mirror 4 of the optical system 4
Since it is necessary to accurately position a and 4b, assembly is complicated, and there is a problem that component costs and assembly costs are increased.

To correct the astigmatic difference of the light beam emitted from the semiconductor laser element 3c, for example, FIG.
As shown in FIG. 1, there is known a semiconductor laser diode 8 having a flat glass 8a as an astigmatic difference correction plate obliquely disposed on the emission side. The light emitting and receiving element 3 is sealed by, for example, a ceramic package. Since it is stopped, it is difficult to incorporate correction means such as an astigmatic difference correction plate for correcting the astigmatic difference inherent to the semiconductor laser element 3c into the light emitting / receiving element 3. Further, such a correction means has a problem that if the wavelength of the light beam of the semiconductor laser element 3c to be used is different, the astigmatism is also different, so that the astigmatism correction plate also needs to be changed accordingly. Was.

Further, when configuring an infinite optical system,
It is necessary to insert a collimator lens in the optical path, and when a high-output semiconductor laser element 3c is used, the difference in the amount of light depending on the polarization direction with respect to the optical axis becomes relatively large. Optical components need to be inserted. Therefore, in these cases, there is a problem that the number of parts increases, and the parts cost and the assembly cost increase.

In view of the above, the present invention provides a light emitting / receiving element for an optical pickup and its cover, in which the number of parts is reduced and the assembly cost is reduced by integrally configuring various optical elements. It is intended to provide.

[0016]

According to the present invention, there is provided, in accordance with the present invention, first and second photodetectors formed on a first semiconductor substrate and mounted on the first semiconductor substrate. A light emitting element that is formed on the second semiconductor substrate and emits a laser beam, and an inclined surface is placed on the first semiconductor substrate and is irradiated with the laser light emitted from the light emitting element. Formed, a semi-transmissive film and an anti-reflective film are formed on the bottom surface,
A micro prism having a total reflection film formed on its upper surface,
A cover covering the light emitting element, the photodetector, and the microprism; and reflecting the laser light from the light emitting element on the inclined surface, and guiding the laser light to the optical disc through one surface of the cover. At the same time, the return light from the optical disk is made incident on the micro prism from the inclined surface through one surface of the cover, and is radiated to the first photodetector. After the light is further reflected by the total reflection film, the light is transmitted through the non-reflection film to irradiate the second photodetector, and an optical element having a specific optical function is provided on one surface of the cover. Is provided integrally by the light receiving and emitting element.

According to the above configuration, the optical element, that is, the light emitting element, is provided on one surface of the upper surface of the semiconductor substrate, the light emitting element, the microprism, and the cover for covering the first and second photodetectors through which the light beam from the light emitting element passes. Since an astigmatic difference correcting plate for correcting the astigmatic difference of the light beam from the element, an anamorphic optical system, a polarization hologram element acting as or equivalent to a collimator lens are integrally formed. The optical element is easily incorporated, and the information signal recorded on the signal recording surface of the optical disk is reproduced based on the light beam affected by the optical element.

[0018]

Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings. Note that the embodiments described below are preferred specific examples of the present invention, and therefore, various technically preferable limitations are added. However, the scope of the present invention is not limited to the following description in the following description. It is not limited to these embodiments unless otherwise stated.

FIG. 1 is a view showing a preferred embodiment of an optical pickup for a compact disk provided with a light emitting / receiving element and a cover according to the present invention. In FIG. 1, an optical pickup 10 includes an objective lens 11 as light converging means, a base (substrate) 12, a light receiving / emitting element 13 disposed on the base 12, and a cover 14 in which an optical system is integrated. And a collimator lens 15.

The optical pickup 10 includes an objective lens 11
Is moved in the focusing direction and the tracking direction, so that the laser light emitted from the light receiving / emitting element 13 passes through the optical system in the cover 14, the collimator lens 15, and the objective lens 11. Is focused and focused at a certain point on the signal recording surface of the optical disc 16 that is driven to rotate. Then, the return light from the signal recording surface of the optical disk 16 is made incident on the light emitting / receiving element 14 via the objective lens 11, the collimator lens 15, and the optical system in the cover 14.

The cover 14 is attached to the base portion 12 so as to cover the entire light emitting / receiving element 13 so as to protect the light emitting / receiving element 13 from the outside air. Here, the optical system in the cover 14 guides the laser light emitted from the light emitting / receiving element 13 to the collimator lens 15 and returns the return light from the optical disc 15 to the objective lens 11 as shown in FIGS. , From the collimator lens 15 to the light receiving / emitting element 13. This optical system includes a cover 14
A first reflecting surface 14a integrally formed on the inner surface of the first lens and a means for astigmatic difference correction integrally provided near the left end in the drawing, for example, a flat plate portion 14b such as a parallel flat plate. Further, the cover 14 further includes a second reflecting surface 14c facing obliquely downward by 45 degrees on the inner surface near the end opposite to the flat plate portion 14b (that is, the right end in the drawing). I have.

The first reflecting surface 14a is arranged at an angle of 45 degrees so that the light beam traveling upward from the light emitting / receiving element 13 is guided substantially parallel along the surface of the base portion 12 by reflection. Have been.

Further, the flat plate portion 14b is
And has a light-transmitting property. As shown in FIG. 2, it is disposed at an inclination angle θ1 with respect to the optical axis of the light beam from the light receiving / emitting element 13. Have been. In this case, the flat plate portion 14b is configured to be adjusted to a different inclination angle, for example, θ2, as shown by a chain line in FIG. By adjusting the inclination of the flat plate portion 14b in accordance with the wavelength of the light beam from the light emitting / receiving element 13, the astigmatic difference is corrected when the light beam passes through the flat plate portion 14b. Become.

Here, the cover 14 is formed of, for example, a plastic material, which is a transparent material.
Transparent optical plastics such as polyester and amorphous polyolefin and polyphenylene sulfide (PP
S), two-color molding with an opaque resin such as a thermosetting epoxy resin, or integral molding with a transparent glass and an opaque resin. Further, the reflection surfaces 14a, 14c
Includes a reflective film (not shown) made of, for example, a dielectric multilayer film or a highly reflective metal film. The inner surface of the cover 14 other than the reflective surfaces 14a and 14c is preferably formed by forming a light absorbing film such as an anti-reflection coating so as to have a characteristic of absorbing unnecessary light. Alternatively, a black paint may be applied, or a black material may be subjected to a surface treatment, and may be formed to be inclined at a predetermined angle to prevent scattering of light (stray light) from the light receiving / emitting element 13. It may be configured.

The laser beam emitted from the light emitting / receiving element 13 is adjusted by the movement and adjustment of the objective lens 11 in the focusing direction and the tracking direction by a biaxial actuator (not shown).
After being converted into parallel light by the collimator lens 15 through the a and the flat plate portion 14b, the light is incident on the objective lens 11, and is further focused and focused on the signal recording surface of the optical disk 16 by the objective lens 11. The return light from the signal recording surface of the optical disk 16 passes through the objective lens 11, the collimator lens 15, and the flat plate portion 14b, and passes through the first reflection surface 14b.
The light is reflected by a and enters the light receiving and emitting element 13.

As shown in FIG. 4, the light receiving / emitting element 13 has a second semiconductor substrate 13b for light output mounted on a first semiconductor substrate 13a, and the second semiconductor substrate 13b.
A semiconductor laser element 13c as a light emitting element is mounted thereon. A trapezoidal micro prism 13 is provided on the first semiconductor substrate 13a in front of the semiconductor laser device 13c.
d is installed with its semi-transmissive inclined surface facing the semiconductor laser element 13c.

Thus, the light beam emitted from the semiconductor laser element 13c along the surface of the second semiconductor substrate 13b is reflected by the inclined surface of the microprism 13d, travels upward, and The light is reflected by the first reflecting surface 14a, passes through the flat plate portion 14c, and proceeds toward the collimator lens 15. Also,
The return light from the signal recording surface of the optical disk 16 passes through the collimator lens 15 and then passes through the flat portion 14b of the cover 14 and the first reflecting surface 14a to form the micro prism 13
The light passes through the inclined surface d and reaches the bottom surface of the microprism 13d. The return light that has reached the bottom surface of the microprism 13d partially transmits through the bottom surface, and is partially reflected by the bottom surface, and travels toward the upper surface of the microprism 13d.

Here, a first photodetector 13e is formed on the first semiconductor substrate 13a below the return light incident position of the microprism 13d. Further, the return light reflected on the bottom surface is reflected on the top surface of the microprism 13d, and is incident on the bottom surface of the microprism 13d again. Then, a second photodetector 13f is formed on the first semiconductor substrate 13a below the bottom portion of the microprism 13d where the return light reflected by the upper surface of the microprism 13d enters. The first light detector 13e and the second light detector 13f are, as shown in FIG.
Each of the sensor blocks A, B, C, D, E, and F is divided into a plurality of (three at the center and both sides in the case shown), and each of the sensor blocks A, B, C, D, E, and F , The detection signals SA, SB, SC, SD, SE, and SF are output independently.

Further, on the first semiconductor substrate 13a,
A third photodetector 13g is provided on the side of the microprism 13d opposite to the second semiconductor substrate 13b. The third photodetector 13g is for monitoring the emission intensity of the semiconductor laser element 13c, and the light beam emitted from the semiconductor laser element 13c enters the microprism 13d from the inclined surface, and After exiting from the end face opposite to the end face d, the light is reflected by the above-mentioned third reflection surface 14d of the cover 14 and enters.

The present embodiment is configured as described above, and the laser light emitted from the semiconductor laser element 13c of the light emitting / receiving element 13 enters the inclined surface of the microprism 13d and is reflected by the inclined surface. . Micro prism 1
The laser light reflected by the 3d inclined surface is reflected by the first reflecting surface 14a of the cover 14, and after correcting the astigmatic difference by the flat plate portion 14b, passes through the collimator lens 15 and the objective lens 11. Is focused on a certain point of a desired track position on the signal recording surface of the optical disc 16. The return light from the optical disk 16 is again transmitted to the objective lens 11, the collimator lens 15, the flat plate portion 14b, and the first reflection surface 14
a through the micro prism 13d of the light emitting / receiving element 13
Incident on the inclined surface of and transmitted through this inclined surface,
Proceed into the microprism 13d.

The return light that has entered the microprism 13d reaches the bottom surface of the microprism 13d, and is partially transmitted and partially reflected toward the upper surface of the microprism 13d. The return light passing through the bottom surface is incident on the first photodetector 13e, while the return light reflected on the bottom surface is reflected on the upper surface of the microprism 13d, passes through the bottom surface of the microprism 13d, The light enters the second photodetector 13f. Here, when the optical disc 16 is in the just focus position, the spots formed on the first photodetector 13e and the second photodetector 13f have the same size as shown in FIG. It is. When the optical disk 16 is near, as shown in FIG. 6, the spot formed on the first photodetector 13e is large and the spot formed on the second photodetector 13f is small. . Further, when the optical disk 16 is far away, FIG.
As shown in (1), the spot formed on the first photodetector 13e is small, and the spot formed on the second photodetector 13f is large.

As described above, the returning light is transmitted to the first photodetector 13.
e and the second photodetector 13f.
The size of the spot formed on each of the photodetectors 13e and 13f changes in accordance with the focus state of the photodetectors 13e and 13f. A focus signal is detected by a so-called differential three division method (D-3DF method),
Further, a tracking error is detected based on a difference between detection signals of the respective sensor units of the first photodetector 13e. For example, in the differential three division method, based on the detection signals SA to SF from the first photodetector 13e and the second photodetector 13f, the focus error signal FE is

(Equation 1) Is obtained by Also, the tracking error signal TE
Is

(Equation 2) Is obtained by Further, the reproduction signal RF is

(Equation 3) Is obtained by

By the way, as shown in FIGS. 2 and 3, when the light beam emitted from the semiconductor laser element 13c of the light emitting / receiving element 13 enters the inclined surface of the microprism 13d, a part of the light beam enters the microprism 13d. Then, after exiting from the opposite end surface of the microprism 13d, the light is reflected by the second reflection surface 14c formed on the inner surface of the cover 14, and is reflected by the third photodetector 13g on the first semiconductor substrate 13a. Incident. Thereby, the semiconductor laser device 13
The amount of emitted light of c is monitored. In this case, since the return light from the optical disk 16 does not enter the third photodetector 13g, interference due to the return light is eliminated, and the amount of light emitted from the semiconductor laser element 13c can be accurately monitored. Is performed. Therefore, the light amount of the light beam applied to the signal recording surface of the optical disc 16 is accurately controlled, and the stability of the reproducing operation of the optical pickup 10 is improved.

In the optical pickup 10 shown in FIG. 1, when the type of the optical disk 16 to be reproduced is different, the wavelength of the light beam emitted from the semiconductor laser element 13c of the light emitting / receiving element 13 may be changed. . In this case, since the astigmatism of the light beam from the semiconductor laser element 13c changes, the inclination angle θ1 of the flat plate portion 14b as the astigmatism correction plate of the cover 14 needs to be changed.
Thus, the flat plate portion 14b can be adapted to the change in the wavelength of the light beam of the semiconductor laser element 13c by being changed to the inclination angle θ2, for example, as shown by a chain line in FIG.

FIG. 8 shows a second embodiment of a cover for a light emitting / receiving element according to the present invention. In FIG.
The cover 20 has basically the same configuration as the cover 14 shown in FIG. 1, but has an aluminum lens part 21 instead of the flat plate part 14 b,
The third semiconductor laser device 13c has a different configuration in that it has a high output. The anamorphic lens unit 21
For example, the optical axis reflected by the first reflecting portion 14a and extending horizontally toward the collimator lens 15 has a relatively large magnification in the horizontal direction and a relatively small magnification in the vertical direction. Thereby, even when the semiconductor laser element 13c having a high output has a different directivity with respect to the polarization direction, the directivity is corrected, the intensity is averaged with respect to the optical axis, and the semiconductor laser element The light beam emitted from 13c is effectively used.

FIG. 9 shows a third embodiment of a cover for a light emitting / receiving element according to the present invention. In FIG.
The cover 30 has basically the same configuration as the cover 14 shown in FIG. 1, but has a polarization hologram element unit 31 instead of the flat plate portion 14b and the collimator lens 15 is omitted. Is a different configuration. The polarization hologram element section 31 has a function of diffracting according to polarized light and converting it into parallel light. That is, the polarization hologram element unit 31 has, for example, an appropriate setting of a hologram pattern, exhibits a diffractive action according to the polarization of the incident light beam, and has a function of a convex lens. For this reason, for example, with respect to the optical axis which is reflected by the first reflection portion 14a and extends horizontally, the light beam reflected by the first reflection surface 14a is converted into parallel light by acting as a collimator lens. As a result, the separate collimator lens 15 is omitted, the number of components of the entire optical pickup is reduced, and the component cost and the assembly cost are reduced.

In the above-described embodiment, the case of the optical pickup 10 for a compact disk has been described. However, the present invention is not limited to this, and the optical pickup 10 for other types of optical disks including a magneto-optical disk such as a mini disk can be used. Obviously, the present invention can be applied to the light receiving / emitting element and its cover.

[0038]

As described above, according to the present invention, a light emitting / receiving element for an optical pickup, in which various optical elements are integrally formed to reduce the number of parts and the assembly cost, is provided. The cover can be provided.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing an optical pickup incorporating a first embodiment of a light receiving / emitting element provided with a cover according to the present invention.

FIG. 2 is an enlarged plan view of a cover in the optical pickup of FIG.

FIG. 3 is an enlarged sectional view of a cover in the optical pickup of FIG.

FIG. 4 is an enlarged perspective view of a light emitting / receiving element in the optical pickup of FIG. 1;

FIG. 5 is an enlarged plan view showing a focused state of first and second photodetectors of a light receiving / emitting element in the optical pickup of FIG. 1;

FIG. 6 is an enlarged plan view showing a case where the optical disks in the first and second photodetectors in FIG. 5 are closer to a focus position.

FIG. 7 is an enlarged plan view showing a case where the optical disc in the first and second photodetectors in FIG. 5 is far from the focus position.

FIG. 8 is a schematic sectional view showing a second embodiment of a light receiving / emitting element provided with a cover according to the present invention.

FIG. 9 is a schematic sectional view showing a third embodiment of a light emitting / receiving element provided with a cover according to the present invention.

FIG. 10 is a schematic view showing an example of a conventional optical pickup.

11 is an enlarged perspective view showing a configuration of a light emitting / receiving element in the optical pickup of FIG.

FIG. 12 is a cross-sectional view of the light emitting and receiving element of FIG.

FIG. 13 is a schematic view showing a configuration example of a semiconductor laser device provided with a glass plate for correcting astigmatism used in a conventional optical pickup.

[Explanation of symbols]

10 optical pickup, 11 objective lens,
12 ... base part, 13 ... light emitting / receiving element, 14 ...
· Cover, 14a ··· first reflective surface, 14b ··· flat plate (astigmatic difference correction plate with adjustable tilt angle), 15 ···
・ Collimator lens, 16 ・ ・ ・ Optical disk, 20,3
0: cover, 21: anamorphic lens part, 31: polarization hologram element (collimator lens).

Claims (5)

[Claims] A first photodetector formed on a first semiconductor substrate; and a second photodetector formed on a second semiconductor substrate mounted on the first semiconductor substrate. A light-emitting element that emits light, is mounted on the first semiconductor substrate, and an inclined surface is formed at a portion where the laser light emitted from the light-emitting element is irradiated, and a semi-transmissive film and a non-reflective film are formed on the bottom surface. A microprism formed and having a total reflection film formed on an upper surface thereof; and a cover for covering a surface of the substrate, a light emitting element, a photodetector, and a microprism. The light is reflected on the inclined surface and guided to the optical disk through one surface of the cover.
The return light from the optical disk is incident on the micro prism from the inclined surface through one surface of the cover, and is irradiated on the first photodetector, and the laser light reflected by the semi-transmissive film is After being further reflected by the total reflection film, the light is transmitted through the non-reflection film and irradiated to the second photodetector. Further, an optical element having a specific optical function is integrated on one surface of the cover. A light emitting and receiving element, comprising: 2. The optical element provided on one surface of the cover is an astigmatic difference correction plate for correcting astigmatic difference of a laser beam from a light emitting element whose tilt angle is supported so as to be adjustable. The light emitting / receiving element according to claim 1, wherein: 3. The light emitting / receiving element according to claim 1, wherein the optical element provided on one surface of the cover has a function of an anamorphic lens. 4. The light emitting / receiving element according to claim 1, wherein the optical element provided on one surface of the cover is a collimator lens or a polarization hologram element that operates equivalently. 5. A first and a second photodetector formed on a first semiconductor substrate, and a laser beam formed on a second semiconductor substrate mounted on the first semiconductor substrate. A light-emitting element that emits light, and is mounted on the first semiconductor substrate, an inclined surface is formed at a portion irradiated with the laser light emitted from the light-emitting element, and a semi-transmissive film and a non-reflective film are formed on the bottom surface. A light-receiving / emitting element having a micro-prism having a total reflection film formed on the upper surface thereof; an upper surface of the first semiconductor substrate, a light-emitting element, a micro-prism, and first and second photodetectors. A cover for the light emitting and receiving element, wherein the optical element is integrally provided on one surface of the cover.