JPH06131692A - Optical head device - Google Patents

Abstract

PURPOSE:To decrease the volumes of both beam splitter and the part of two photodetectors. CONSTITUTION:The beam splitter 11 is comprised of a light separating plane 11d which partially transmits incident light from a light incident plane 11c and separates it by reflecting a part of it, a light emitting plane 11b which emits light transmitting the light separating plane lid, and a light emitting plane 11a which emits by refracting the light reflected on the light separating plane 11d. The incident angle of the incident light Pin for the light separating plane 11d is set at >=45 deg., and an angle formed between the emitting light Pa and Pb at <90 deg., and the light can be received by the photodetectors 12a, 12b on a light receiver 12.

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,
In particular, the present invention relates to an optical head device in which the beam splitter and the light receiving element are downsized.

[0002]

2. Description of the Related Art In recent years, a demand for a small-sized and large-capacity memory has remarkably increased, and various products have been developed. Among them, the optical disc device using an optical disc and the magneto-optical disc device using a magneto-optical disc are highly expected.

The above-mentioned optical disk device and the like are currently under intensive development and improvement, and the most important elemental technology among them is
This is a part of an optical head device (hereinafter, also simply referred to as “optical head”).

The above optical head is constructed by using various optical elements, and among them, a beam splitter for separating light is often used.

FIG. 12 is a view showing an example of a conventional beam splitter, which is a beam splitter 121 and a light receiving element 1.
It is a figure which shows the arrangement | positioning relationship of 22,123, and is an example in which light is split into two directions by the beam splitter 121 and each light is received by the light receiving elements 122,123.

An example in which light is separated by using a beam splitter and detected by a light receiving element is often used in an optical head device. In particular, in a magneto-optical disk device, a polarization beam splitter is used as the beam splitter 121. Often adopted.

FIG. 13 is a diagram showing an example of a system configuration of a conventional optical head, which is an example of the configuration of an optical head used in a magneto-optical disk device, and shows an example of using a polarization beam splitter.

In FIG. 13, a semiconductor laser (LD) 1
The light output from 31 is converted into parallel light by the collimator lens 132, transmitted through the beam splitter 133, reflected by the rising mirror 134, passes through the objective lens 135, and forms a spot on the magneto-optical disk 136.

The reflected light from the magneto-optical disk 136 passes through the objective lens 135 and is reflected by the rising mirror 134.
The light is reflected by the beam splitter 133 (the light from the light emitting element is separated from the optical axis), passes through the half-wave plate 137 and the converging lens 138, and is polarized and separated by the beam splitter 121.
One enters the light receiving element 122 and the other enters the light receiving element 123.

As described above, the polarization beam splitter 121
Depolarizes the reflected light from the magneto-optical disk 136,
The separated light is received by the two light receiving elements 122 and 123.

[0011]

As described above,
A conventional beam splitter for separating light is shown in FIGS.
As shown in the example of No. 3, the light is separated in the orthogonal direction.

Therefore, due to the structure, the beam splitter 121
Therefore, the volume of the components of the two light receiving elements 122 and 123 must be physically increased. In order to reduce the volume, the beam splitter 121 and the light receiving element 12
It is conceivable to reduce the distance between 2,123, but it cannot be made too small because the packages of the light receiving elements interfere with each other.

The Wollaston prism 14 shown in FIG.
Although an example using 1 may be considered, since the angle of the separated light is about 1 degree, it is necessary to increase the distance between the Wollaston prism 141 and the light receiving element 142, resulting in a large volume. Further, since the Wollaston prism 141 itself is expensive, the cost of the entire device increases.

The present invention has been made in view of the above problems, and an object of the present invention is to provide an optical head device in which the components of the beam splitter and the light receiving element are downsized.

[0015]

According to another aspect of the present invention, there is provided an optical head device comprising: first optical means for separating reflected light from a recording medium from an optical axis extending from a light emitting element to the recording medium;
The angle formed by the optical axes of the light separated by the optical means is 90
An optical head device comprising: a second optical unit that splits the light into two beams so that the light intensity is less than 1 degree; and a light receiving unit that includes two light receiving units that respectively receive the light beams split by the second optical unit. The beam splitter 11 as the second optical means includes a light incident surface 11c as an incident surface on which the light separated by the first optical means is incident, and a part of the light incident from the incident surface is partially transmitted and partially reflected. Then, a light splitting surface 11d as a light splitting surface that splits the light into two lights, and a light output surface 11 as a first output surface that outputs the light that has passed through the light splitting surface 11d.
b, and a light emission surface 11a as a second emission surface for emitting the light reflected by the light separation surface 11d, and at least one of the light emission surface 11b and the light emission surface 11a refracts light. The light receiver 12 as a light receiving means is characterized by receiving the light emitted from the light emitting surface 11a and the light emitting surface 11b.

According to another aspect of the optical head device of the present invention, the reflected light from the recording medium is separated from the optical axis from the light emitting element to the recording medium by the first optical means and the first optical means. A light receiving unit that includes a second optical unit that splits the light into two beams so that the angle formed by the optical axis is less than 90 degrees, and two light receiving units that respectively receive the light beams split by the second optical unit. In an optical head device provided with means,
The beam splitter 21 as the second optical means is the first
The light incident surface 21c as the incident surface on which the light separated by the optical means is incident, and the light emitting surface as the first emitting surface for emitting a part of the light incident from the incident surface and internally reflecting a part of the light. The light receiving surface 21b has a surface 21b and a light emitting surface 21a as a second emitting surface for refracting and outputting the light internally reflected by the light emitting surface 21b. It is characterized by receiving the light emitted from the emission surface 21b.

According to another aspect of the optical head device of the present invention, the beam splitter 11 as the second optical means has polarization components in which the light beams separated by the first optical means are orthogonal to each other.
3. The optical head device according to claim 1, wherein the optical head device separates the light into two light beams, and emits the respective light beams from an emission surface 11b as a first emission surface and an emission surface 11a as a second emission surface. is there.

In the optical head device according to a fourth aspect of the invention, the light receiving surfaces of the light receiving elements 12a and 12b as the two light receiving portions in the light receiver 12 as the light receiving means are arranged in substantially the same direction. The optical head device according to claim 1, 2 or 3, wherein

An optical head device according to a fifth aspect of the invention is one in which light receiving elements 63a and 63b as two light receiving portions are arranged on one substrate 62 in a light receiving device 61 (FIG. 6) as light receiving means. It is characterized by the above-mentioned.
The optical head device described above.

In the optical head device according to the present invention, the light receiving elements 102a and 102b as the two light receiving portions in the package 103 (FIG. 10) as the light receiving means are formed by one semiconductor wafer. The optical head device according to claim 1, 2 or 3, wherein the optical head device is an element.

An optical head device according to a seventh aspect of the present invention is a medium driving means for driving a recording medium, an optical head moving means for moving the optical head with respect to the recording medium,
An optical recording / reproducing device comprising the optical head device described in item 4, 5 or 6.

[0022]

In the optical head device having the structure of the first aspect, the incident light Pin is partially reflected by the light separation surface 11d and partially transmitted, and the reflected light is refracted and emitted by the light emission surface 11a. In this way, the angle formed by the light Pa and the light Pb is 9
The light Pa and the light Pb are received by the light receiving elements 12a and 12b on the light receiver 12 so that the angle is less than 0 degree (this angle is preferably as small as possible).

As described above, the beam splitter 1 of the present invention
By using 1, the constituent parts of the beam splitter 11 and the light receiver 12 can be structurally made small. Further, the two light receiving elements 12a and 12b can be housed in the same package, and the number of parts can be reduced, so that the number of adjustment points can be reduced.

According to another aspect of the optical head device of the present invention, the incident light Pin is partially reflected by the light emission surface 21b and partially transmitted, and the reflected light is refracted at the emission surface 21a and emitted. In this way, the angle formed by the light Pa and the light Pb is 90
The light Pa and the light Pb are set to be less than 10 degrees (this angle should be as small as possible), and
Light is received by 2a and 22b.

Thus, the beam splitter 2 of the present invention
By using 1, the constituent parts of the beam splitter 21 and the light receiver 22 can be structurally made small. Further, the two light receiving elements 22a and 22b can be housed in the same package, the number of parts can be reduced, and the number of adjustment points can be reduced.

In the optical head device of the third aspect, for example, when the beam splitter 11 or the like is used in a magneto-optical disk device, an optical film for polarization separation is formed on the light separation surface 11d or the like, Used as a polarization beam splitter.

In the optical head device having the structure described in claim 4, the two light receiving elements 12a and 12b in the light receiver 12 are provided.
Are arranged so that the light receiving surfaces of are oriented in substantially the same direction. By doing so, the structure of the light receiver 12 can be reduced in size, and one package can be realized.

In the optical head device having the structure described in claim 5, two light receiving elements 6 are provided on one substrate 62 (FIG. 6).
3a and 63b are arranged. By doing so, the structure of the light receiver 61 can be reduced in size, and one package can be realized.

In the optical head device of the sixth aspect, the light receiving element 102a and the light receiving element 102b (see FIG.
0) is formed on one silicon chip 101.

As described above, by forming the light receiving element into one chip, both light receiving regions are simultaneously formed on one silicon wafer in the same manufacturing process. An effect such as high accuracy can be obtained.

In the optical head device having the structure described in claim 7, the optical head device of the present invention is applied to an optical recording / reproducing device for moving the optical head device with respect to the optical disk. That is, since the optical head device of the present invention is smaller than the conventional one, the drive device can be downsized, and the processing speed can be increased by using the lightweight optical head device.

[0032]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a diagram showing an example of the construction of a beam splitter according to the first embodiment of the present invention.
It is an embodiment commonly corresponding to the described invention.

In FIG. 1, the light Pin is the light incident surface 11c.
And enters the beam splitter 11 (second optical means). The incident light Pin is partially reflected by the light separation surface 11d and partially transmitted to be separated. The light reflected by the light splitting surface 11d is refracted by the light exit surface 11a (second exit surface) and is converted into the light Pa.
Is emitted as. The light transmitted through the light separation surface 11d is emitted as the light Pb from the light emission surface 11b (first emission surface).
The emitted light Pa and the light Pb are received by the light receiving elements 12a and 12b in the light receiver 12 (light receiving means), respectively.

In the embodiment shown in FIG. 1, the incident angle of the incident light Pin with respect to the light separation surface 11c is set to 45 degrees or more, and the light is refracted at the light emission surface 11a, so that the light P
The angle between a and the light Pb is set to less than 90 degrees (this angle is preferably as small as possible), and the light Pa and the light Pb are set.
Is received by the light receiving elements 12a and 12b on the light receiver 12.

Thus, the beam splitter 1 of the present invention
By using 1, the constituent parts of the beam splitter 11 and the light receiver 12 can be structurally made small. Further, the two light receiving elements 12a and 12b can be housed in the same package, the number of parts can be reduced, and the number of adjustment points can be reduced.

When the beam splitter 11 shown in FIG. 1 is used in a magneto-optical disk device, an optical film is formed on the light splitting surface 11d and the beam splitter 11 is used as a polarization beam splitter.

FIG. 2 is a diagram showing a configuration example of a beam splitter of the second embodiment of the present invention, which is an example in which the light splitting surface 12d and the light emitting surface 12b in the embodiment of FIG. 1 are made common. .
Note that this is an embodiment commonly corresponding to the inventions described in claims 2, 3 and 4.

In FIG. 2, the light Pin is the light incident surface 21c.
Enters the beam splitter 21 (second optical means). The incident light Pin is emitted from the light exit surface 21b (first exit surface).
The light is partly reflected and partly transmitted and separated. Light emitting surface 21
The light reflected by b is refracted at the light emitting surface 21a (second emitting surface) and emitted as light Pa. The light transmitted through the light emitting surface 21b is refracted and emitted as the light Pb. Emitted light Pa,
The light Pb is received by the light receiving elements 22a and 22b in the light receiver (light receiving means) 22, respectively.

In the embodiment shown in FIG. 2, the incident angle of the incident light Pin with respect to the light emitting surface 21b is 45 degrees or more, and the light is refracted and emitted by the light emitting surface 21a and the light emitting surface 21b. The angle between Pa and light Pb is 9
The light is received by the light receiving elements 22a and 22b so that the angle is less than 0 degree.

Thus, the beam splitter 2 of the present invention
By using 1, the constituent parts of the beam splitter 21 and the light receiver 22 can be structurally made small. Further, the two light receiving elements 22a and 22b can be housed in the same package, the number of parts can be reduced, and the number of adjustment points can be reduced.

When the beam splitter 21 of FIG. 2 is used in a magneto-optical disk device, an optical film is formed on the light emitting surface 21b and the beam splitter 21 is used as a polarization beam splitter.

FIG. 3 is a diagram showing a structural example of a beam splitter of a third embodiment of the present invention, which is an embodiment commonly corresponding to the inventions described in claims 1, 3 and 4.

In FIG. 3, the light Pin is the light incident surface 31c.
Enters the beam splitter 31. The incident light Pin is partially reflected by the light separation surface 31d and partially transmitted, and is separated. The light reflected by the light separation surface 31d is refracted at the light emission surface 31a and emitted as light Pa, and the light transmitted through the light separation surface 31d is refracted at the light emission surface 31b and emitted as Pb.
The light Pa and the light Pb are received by the light receiving elements 32a and 32b in the light receiving device 32 for light detection, respectively.

In the embodiment shown in FIG. 3, the incident light Pin is partially reflected by the light separation surface 31d and partially transmitted, and the light is refracted on both surfaces of the light emission surfaces 31a and 31b. The angle between the light Pb and the light Pb is less than 90 degrees, and the light Pa and the light Pb are received by the light receiving element 32 on the light receiver 32.
Light is received by a and 32b.

As described above, the beam splitter 3 of the present invention is used.
By using 1, the components of the beam splitter 31 and the light receiver 32 can be structurally made small. Further, the two light receiving elements 32a and 32b can be housed in the same package, the number of parts can be reduced, and therefore the number of adjustment points can be reduced.

When the beam splitter 31 shown in FIG. 3 is used in a magneto-optical disk device, an optical film is formed on the light splitting surface 31d and the beam splitter 31 is used as a polarization beam splitter.

FIG. 4 is a diagram showing an example of the construction of a beam splitter according to the third embodiment of the present invention.
It is an embodiment commonly corresponding to the described invention.

In FIG. 4, the light Pin is the light incident surface 41c.
Enters the beam splitter 41. Incident light Pin
Is partially reflected by the light emitting surface 41b and partially transmitted, so that the light is separated. The light reflected by the light emitting surface 41b is refracted by the light emitting surface 41a and emitted as light Pa. The light transmitted through the light emitting surface 41b is refracted and emitted as light Pb. Emitted light Pa,
The light Pb is received by the light receiving elements 42 a and 4 in the light receiver 42, respectively.
The light is received by 2b.

The embodiment of FIG. 4 shows an example in which the incident light Pin may be incident on the light emitting surface 41b at an incident angle of 45 degrees. Further, in this example, the light Pa is changed by refracting the light on both the light emitting surface 41a and the light emitting surface 41b.
The angle between the light Pb and the light Pb is less than 90 degrees, and the light Pb
The light receiving elements 42a and 42b on the light receiver 42 receive a and the light Pb.

Thus, the beam splitter 4 of the present invention is
By using 1, the constituent parts of the beam splitter 41 and the light receiver 42 can be structurally made small. Further, the two light receiving elements 42a and 42b can be housed in the same package, the number of parts can be reduced, and therefore the number of adjustment points can be reduced.

When the beam splitter 41 of FIG. 4 is used in a magneto-optical disk device, an optical film is formed on the light emitting surface 41b and the beam splitter 41 is used as a polarization beam splitter.

FIG. 5 is a diagram showing an example of the construction of a beam splitter according to the fifth embodiment of the present invention.
It is an embodiment commonly corresponding to the described invention.

In FIG. 5, the light Pin is the light incident surface 51c.
Is refracted and enters the beam splitter 51. The incident light Pin is partially reflected by the light emitting surface 51b and partially transmitted, and is separated into light. The light reflected by the light emitting surface 51b is the light emitting surface 5
The light is refracted at 1a and emitted as light Pa. Light emitting surface 51b
The light transmitted through is refracted and emitted as light Pb. The emitted light Pa and the light Pb are respectively received by the light receiving element 52 in the light receiver 52.
The light is received by a and 52b.

In the embodiment shown in FIG. 5, the incident light Pin is refracted by the light incident surface 51c to enter the light, the incident light Pin is partially reflected by the light emitting surface 51b and partially transmitted, and the light emitting surface 51a and By refracting the light at the light emitting surface 51b, the angle between the light Pa and the light Pb is set to be less than 90 degrees. Then, the light Pa and the light Pb are received by the light receiving elements 52a and 52b on the light receiver 52.

Thus, the beam splitter 5 of the present invention is
By using 1, the parts of the beam splitter 51 and the light receiver 52 can be structurally made small. Further, the two light receiving elements 52a and 52b can be housed in the same package, the number of parts can be reduced, and therefore the number of adjustment points can be reduced.

When the beam splitter 51 of FIG. 5 is used in a magneto-optical disk device, an optical film is formed on the light emitting surface 51b and the beam splitter 51 is used as a polarization beam splitter.

FIG. 6 is a diagram showing a first structural example of a light receiving element used in the optical head device of the present invention. FIG. 6A is a diagram for explaining the arrangement of the light receiving element and the light receiving state. 6
(B) is an external perspective view. The present example is an example commonly corresponding to the inventions described in claims 4 and 5.

In FIG. 6, a light receiver 61 is one in which two light receiving elements 63a and 63b are arranged on a substrate 62 and covered with a resin mold 64 made of a transparent material. The beam splitter 65 in the figure is a simplified representation of the beam splitter according to the present invention shown in FIGS. 1 to 5.

In the example of FIG. 6, since the incident light Pin is split by the beam splitter according to the present invention at a narrow angle of less than 90 degrees, the light receiving elements 63a and 63b can be arranged at a short distance, and the light receiving elements 63a, 63a, This is an example in which 63b is stored in one substrate 61.

FIG. 7 is a diagram showing a second configuration example of the light receiving element used in the optical head device of the present invention, and FIG. 7A is a diagram for explaining the arrangement of the light receiving element and the light receiving state. 7
(B) is an external perspective view. The present example is an example commonly corresponding to the inventions described in claims 4 and 5. Also,
The parts corresponding to those in the example of FIG. 6 are designated by the same reference numerals, and the description thereof will be omitted as appropriate.

In FIG. 7, a light receiver 71 has two light receiving elements 63a and 63b arranged on a substrate 72 and covered with a resin mold 74 made of a transparent material. In this example, the surface on which the light receiving elements 63a and 63b are arranged is a plane,
A step is provided on each plane.

FIG. 8 is a diagram showing a third configuration example of the light receiving element used in the optical head device of the present invention, and FIG. 8A is a diagram for explaining the arrangement of the light receiving element and the light receiving state. 8
(B) is an external perspective view. The present example is an example commonly corresponding to the inventions described in claims 4 and 5. Also,
The parts corresponding to those in the example of FIG. 6 are designated by the same reference numerals, and the description thereof will be omitted as appropriate.

In FIG. 8, a light receiver 81 is one in which two light receiving elements 63a and 63b are arranged on a substrate 82 and covered with a resin mold 84 made of a transparent material. In this example, the light receiving elements 63a and 63b are arranged on the same plane,
In addition, the surface of the transparent mold 84 is formed into a spherical surface, and the incident light Pa and the light Pb are focused on the light receiving elements 63a and 63b.

FIG. 9 is a diagram showing a fourth configuration example of the light receiving element used in the optical head device of the present invention. FIG. 9A is a diagram for explaining the arrangement of the light receiving element and the light receiving state. 9
(B) is an external perspective view. The present example is an example commonly corresponding to the inventions described in claims 4 and 5. Also,
The parts corresponding to those in the example of FIG. 6 are designated by the same reference numerals, and the description thereof will be omitted as appropriate.

In FIG. 9, a light receiver 91 has two light receiving elements 63a and 63b arranged on a substrate 92 and covered with a resin mold 94 made of a transparent material. In this example, the light receiving elements 63a and 63b are arranged on the same plane, and an inclined surface is provided in a part of the transparent mold 94, and the incident light Pa of the light receiving element 63a is refracted by the inclined surface. It was made to let,

As described above, by using the beam splitter of the present invention, it becomes possible to package two light receiving elements into one package, and further, it becomes possible to form these light receiving elements into one chip.

FIG. 10 is a diagram showing a one-chip configuration example of the light receiving element used in the optical head device of the present invention.
10A is a top view, FIG. 10B is a right side view, and FIG.
10C shows a bottom view, and FIG. 10D shows a chip layout. The present embodiment is an embodiment commonly corresponding to the inventions described in claims 4, 5 and 6.

(1) First, as shown in FIG. 10D, the light receiving element 102a and the light receiving element 102b (in this example, the four-division photodetector) are combined into one silicon chip 101.
Form on top.

(2) Next, the light receiving elements 101a and 102b on the silicon chip 101 are covered with a transparent resin mold (see FIGS. 6 to 9).

(3) Then, the entire chip 101 is housed and fixed in the package 103, and the lead terminals 104 are provided.

As shown in FIG. 10, the following effects can be obtained by forming the light receiving element into one chip. (1) Since both light-receiving regions are simultaneously formed on one silicon wafer in the same manufacturing process, the positional relationship such as the light-receiving region interval is accurate. (2) The bonding process can be simplified (since only one process is required).

Although the configuration examples of the beam splitter and the light receiving element according to the present invention have been described above, the cases in which the present invention can be effectively applied will be described below by way of examples.

FIG. 11 is a diagram showing an application example of the optical head of the present invention to a magneto-optical disk device.

(1) For example, in the case of the configuration example of the magneto-optical disk device of FIG. 11A, the polarization beam splitter 115 is replaced by the beam splitter of the present invention (FIGS. 1 to 5). It can be applied effectively. In addition,
In FIG. 11A, 111 is a light emitting element, 112 is a light receiving element, 112a is a light receiving element, 112b is a light receiving element (four-division photodetector), 113 is a collimator lens, 114, 1
Reference numeral 15 represents a polarization beam splitter. Also, FIG.
1 (b) shows the configuration of the light receiver 112 as viewed from the front.

(2) Further, in the case of the diagram showing the configuration example of the magneto-optical disk device of FIG. 11C, instead of the polarization beam splitter 115 in the figure, the beam splitter of the present invention (see FIGS. 5) can be effectively used. In FIG. 11C, 116 is a beam splitter, 117 is a rising mirror, 118 is an aspherical objective lens,
Reference numeral 119 represents a magneto-optical disk, and other symbols are those shown in FIG.
It is the same as the case of (a). Note that the light receiver 112 and the polarization beam splitter 115 are actually 4
It is at a position rotated by 5 degrees, and the rising mirror 117 and the objective lens 118 are at positions rotated by 90 degrees about the optical axis.

In the present invention, the optical head device 152 is
It can be suitably used for an optical recording / reproducing apparatus in which the feed motor 153 moves the magneto-optical disk 119 rotated by the spindle motor 151. That is, since the optical head device 152 of the present invention is smaller than the conventional one, the drive device can be downsized. Also,
By using the lightweight optical head device of the present invention, the processing speed can be increased.

[0077]

According to the optical head device of the first aspect,
The incident light Pin is partially reflected by the light separation surface 11d and partially transmitted, and the reflected light is refracted and emitted by the light emission surface 11a so that the angle between the light Pa and the light Pb is less than 90 degrees. Since the light Pa and the light Pb are received by the light receiving elements 22a and 22b, the components of the beam splitter 11 and the light receiver 12 can be structurally made small. In addition, two light receiving elements 2
2a and 22b can be stored in the same package,
The number of parts can be reduced, and therefore the number of adjustment points can be reduced.

According to the optical head device of the second aspect, the incident light Pin is partially reflected by the light emitting surface 21b and partially transmitted,
The reflected light is refracted at the light emitting surface 21a, and the light Pa and the light P
Since the angle formed by b is set to less than 90 degrees and the light Pa and the light Pb are received by the light receiving elements 22a and 22b, the components of the beam splitter 21 and the light receiver 22 can be structurally downsized. In addition, the two light receiving elements 22a, 2
2b can be housed in the same package, the number of parts can be reduced, and therefore the number of adjustment points can be reduced.

According to the optical head device of the third aspect, since the optical film for polarization separation is formed on the light separation surface 11d and the like and is used as a polarization beam splitter, the optical head in the magneto-optical disk device. The size of the device can be reduced.

According to the optical head device of the fourth aspect, the light-receiving surfaces of the two light-receiving elements 12a and 12b in the light-receiving device 12 are arranged so as to face substantially the same direction. The configuration can be downsized, and one package can be easily made.

According to the optical head device of the fifth aspect, since the two light receiving elements 63a and 63b are arranged on the substrate 62, the structure of the light receiving device 61 can be downsized and one package can be formed. It will be easier.

In the optical head device according to claim 6,
Since the light receiving element 102a and the light receiving element 102b are formed on one silicon chip 101, both light receiving areas are simultaneously formed on one silicon wafer in the same manufacturing process. It is possible to obtain the effect that the positional relationship such as is accurate.

According to the optical head device of the present invention, the optical head device of the present invention is used for the optical recording / reproducing device for moving the optical head with respect to the optical disk. It can be miniaturized and can be processed at high speed because it is lightweight.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration example of a beam splitter according to a first embodiment of the present invention.

FIG. 2 is a diagram showing a configuration example of a beam splitter according to a second embodiment of the present invention.

FIG. 3 is a diagram showing a configuration example of a beam splitter of a third embodiment of the present invention.

FIG. 4 is a diagram showing a configuration example of a beam splitter according to a fourth embodiment of the present invention.

FIG. 5 is a diagram showing a configuration example of a beam splitter according to a fifth embodiment of the present invention.

FIG. 6 shows a first light receiving element used in the optical head device of the present invention.
It is a figure which shows the structural example.

FIG. 7 shows a second light receiving element used in the optical head device of the present invention.
It is a figure which shows the structural example.

FIG. 8 is a third photodetector used in the optical head device of the present invention.
It is a figure which shows the structural example.

FIG. 9 is a fourth photodetector used in the optical head device of the present invention.
It is a figure which shows the structural example.

FIG. 10 is a diagram showing a one-chip configuration example of a light receiving element used in the optical head device of the present invention.

FIG. 11 is a diagram showing an example of application of the optical head of the present invention to a magneto-optical disk device.

FIG. 12 is a diagram showing an example of a conventional beam splitter.

FIG. 13 is a diagram showing an example of a system configuration of a conventional optical head.

FIG. 14 is a diagram showing an example of use of a Wollaston prism.

[Explanation of symbols]

11, 21, 31, 41, 51 Beam splitter (second optical means) 11a, 21a, 31a, 41a, 51a Light emission surface (second emission surface) 11b, 21b, 31b, 41b, 51b Light emission surface ( First emission surface) 11c, 21c, 31c, 41c, 51c Light incident surface 11d, 31d Light separation surface 12, 22, 32, 42, 52 Light receiver 12a, 22a, 32a, 42a, 52a Light receiving element 12b, 22b, 32b, 42b, 52b Light receiving element 61, 71, 81, 91 Light receiving element 62, 72, 82, 92 Substrate 63a, 63b Light receiving element 64, 74, 84, 94 Transparent resin mold 65 Beam splitter 101 Silicon chip 102a, 102b Light-receiving element on chip 103 Package 104 Lead terminal

Claims (7)

[Claims] 1. An angle formed between a first optical means for separating reflected light from a recording medium from an optical axis from a light emitting element to the recording medium and an optical axis for the light separated by the first optical means. An optical head device comprising: a second optical unit that splits the light into two beams with an angle of less than 90 degrees; and a light receiving unit that includes two light receiving units that respectively receive the light beams split by the second optical unit. The second optical means includes an incident surface on which the light separated by the first optical means is incident, and a light separation device that partially transmits and partially reflects the light incident from the incident surface to separate the light into two lights. A surface, a first emission surface that emits light that has passed through the light separation surface, and a second emission surface that emits light that is reflected by the light separation surface, and further includes the first emission surface and the second emission surface. At least one of the exit surfaces of the light refracts light and emits the light. Means, an optical head device, characterized by receiving the light emitted from the first emission surface and the second emission surface. 2. The angle formed between the first optical means for separating the reflected light from the recording medium from the optical axis from the light emitting element to the recording medium and the optical axis for the light separated by the first optical means An optical head device comprising: a second optical unit that splits the light into two beams with an angle of less than 90 degrees; and a light receiving unit that includes two light receiving units that respectively receive the light beams split by the second optical unit. The second optical means includes an incident surface on which the light separated by the first optical means is incident, and a first emission for emitting a part of the light incident from the incident surface and internally reflecting a part of the light. A surface and a second emission surface that refracts the light internally reflected by the first emission surface and emits the light. The light receiving means emits light from the first emission surface and the second emission surface. An optical head device, which receives the emitted light. 3. The second optical means separates the light separated by the first optical means into two lights whose polarization components are orthogonal to each other, and the respective lights are separated into a first emission surface and a second emission surface. The optical head device according to claim 1, wherein the optical head device emits light from a surface. 4. The light receiving means is such that the light receiving surfaces of the two light receiving portions are
4. The optical head device according to claim 1, wherein the optical head devices are arranged in substantially the same direction. 5. The light-receiving means has two light-receiving portions arranged on one substrate.
2. The optical head device according to 2 or 3. 6. The optical head device according to claim 1, 2 or 3, wherein the light receiving means is a one-chip light receiving element in which the two light receiving portions are manufactured from one semiconductor wafer. 7. A medium driving means for driving a recording medium, an optical head moving means for moving the optical head with respect to the recording medium, and the optical head device according to claim 1, 2, 3, 4, 5 or 6. An optical recording / reproducing device characterized by being provided.