JP2001298236A - Multi-beam integrated optical unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To narrow the beam spacing in a multi-beam integrated optical unit. SOLUTION: The multi-beam integrated optical unit has a plurality of semiconductor laser elements for emitting laser beams having mutually different wavelengths used for irradiating an optical disc surface of an optical disc unit, and a plurality of photo detectors for receiving laser beams reflected on the optical disc surface. It comprises a semiconductor substrate, the plurality of semiconductor laser elements fixed to a main surface of the substrate, and a plurality of mutually different reflective surfaces formed on the main surface of the substrate. The positions and the orientations of the reflective surface and each laser element are set so that the laser beam emitted from each laser element is reflected on the reflective surface and can be used as a laser beam irradiating the optical disc surface. The mutual spacing between the emitted laser beams is shorter than the width of the element end face, including the radiating surface for radiating the laser beam of the laser element.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-beam integrated optical unit, and more particularly, to a multi-beam integrated optical unit which incorporates a plurality of semiconductor laser elements and emits light having different laser beam wavelengths by switching semiconductor laser elements. The present invention relates to a technique for simultaneously emitting laser beams in parallel, and is applied to, for example, an optical pickup unit of an optical disk device having a compact disk system and a digital video disk system, or a light source unit of a laser beam printer that emits multiple beams. Regarding effective technology.

[0002]

2. Description of the Related Art CD (Compact Disc), CD-ROM
(Compact Disc Read Only Memory), High-speed recording CD-
R (Compact Disc-Recordable) is widely used as a medium for music, personal computer (PC) data and software. In addition, DVD (Digital Video Disk), DV
D-ROM, DVD-RAM (Random Access Memory)
Has been put to practical use.

A hologram laser as an optical pickup for a CD or DVD is described in “Electronic Materials”, November 1999, published by the Industrial Research Council, pages P47 to P53. Japanese Patent Application Laid-Open No. 11-66590 discloses a DVD for reflecting laser light emitted from a laser element fixed on a silicon substrate on a silicon mirror surface provided on the silicon substrate and passing the laser light through a hologram optical system. An optical pickup device is disclosed. The silicon substrate is provided with a laser element, a monitoring light receiving element, a divided light receiving element for detection, and an integrated circuit (in which an amplifier circuit connected to the output stage of the divided light receiving element is integrated).

[0004] The optical pickup of a DVD device is described in the above-mentioned "Opplus E", pp. 86-92. This document describes various systems such as a bifocal system, a two-lens system, a two-laser system, and an aperture limiting system as compatible systems for DVD and CD.

On the other hand, "Electronic Materials" published by the Industrial Research Institute, 1999
In the November issue, P54 and P55, a one-chip two-wavelength laser diode and a monolithic two-wavelength semiconductor laser for CD / DVD reproduction are disclosed. These semiconductor lasers (laser diodes) include a 780 nm band semiconductor laser (for CD) and a 650 nm band semiconductor laser (DVD).
Is monolithically integrated.

[0006]

SUMMARY OF THE INVENTION CD, CD-ROM,
CD-Rs are widely used as music, personal computer data, and software media, but have insufficient capacity to handle large amounts of data such as moving images. For this reason, as a large-capacity disk, the wavelength of the laser is changed from the 780 nm band to 650 n
DVD, DVD- with shorter wavelength in the m band and higher recording density
ROM and DVD-RAM have been put to practical use.

It is inconvenient to prepare separate optical pickup sets for different types of disks. It is desirable to use a set in which data of all these disks can be read by one device. CD-R has a large wavelength dependence of reflectance, and 780 nm.
It can only be read with a light source in the nm band. Therefore, CD-R and D
The optical pickup set that can support both VD is 650
It is necessary to use a semiconductor laser (LD) having two wavelengths of the nm band and the 780 nm band.

However, in such a configuration, the optical system of the optical pickup is complicated, the volume is large, and the manufacturing cost of the optical disk device is high. Therefore, the present inventor has adopted the conventional structure, fixed two semiconductor laser elements on the main surface side of the semiconductor substrate, and switched the 650 nm band and 780 nm band laser light to the semiconductor substrate by switching operation of the semiconductor laser elements. A multi-beam integrated optical unit that radiates perpendicular to the main surface was studied.

FIG. 20 is a schematic view showing a part of a multi-beam integrated optical unit studied by the present inventors. The multi-beam integrated optical unit has a substrate, for example, a semiconductor substrate 1, as shown in FIG. The main surface of the semiconductor substrate 1 is provided with a depression 2 which is one step lower, and two semiconductor laser elements (semiconductor laser chips) 3a and 3b are provided on the bottom surface 4 of the depression 2 with respective optical waveguides (resonators). 5a and 5b are fixed side by side so as to be parallel.

The inner peripheral wall surface of the recess 2 facing the front emission surface of the semiconductor laser chips 3a and 3b which emits laser light is a reflection surface 6 inclined with respect to the bottom surface 4. The reflection surface 6 has an angle of 45 degrees with respect to the bottom surface 4. Therefore, the laser beams (laser beams) 7a and 7b emitted from the semiconductor laser chips 3a and 3b are reflected by the reflecting surface 6 and are directed to the laser beams 7a and 7b traveling perpendicular to the main surface of the semiconductor substrate 1. Become.

However, in such a structure in which the two semiconductor laser chips 3a, 3b are arranged in parallel, the interval a between the two laser beams 7a, 7b is set to be equal to the laser beam 7a, 3b of the semiconductor laser chips 3a, 3b. It cannot be smaller than the width of the end face of the element (chip end face) having an emission surface for emitting 7b. That is, the optical waveguides 5a and 5b are generally provided along the center of the chip width. Further, the two semiconductor laser chips 3a and 3b are fixed to the semiconductor substrate 1 in a state where they are separated from each other by a predetermined distance because of the chip fixing and the like. Therefore, the distance between the two optical waveguides 5a and 5b is a dimension obtained by adding the chip width and the predetermined distance.

Although the semiconductor laser chips 3a and 3b have various chip widths, for example, about 300 μm is often employed. Therefore, when a semiconductor laser element having such dimensions is used, the distance between two laser beams (laser beams) 7a and 7b reflected by the reflecting surface 6 cannot be smaller than about 300 μm.

A monitoring light receiving element (photodiode) PD for reading information from an optical disk, a focus error,
Provided are divided light receiving elements for detection (photodiodes for signal detection) PD1 to PD6 for detecting a tracking error and the like, an integrated circuit (IC) 9 including an amplifier circuit connected to an output stage of the divided light receiving elements, and an electrode pad 10. ing.

However, in such a structure, the interval between the laser beams 7a and 7b reflected by the reflecting surface 6 is widened,
It becomes necessary to increase the effective area of the collimator lens for converting the laser beams 7a and 7b into parallel light, which increases the lens cost. As a result, the cost of the multi-beam integrated optical unit increases. On the other hand, in a writable optical disk system, a high-output semiconductor laser must be used. In a high-power semiconductor laser device, it is necessary to accurately control the end face reflectance of the front emission surface in order to secure light output, suppress an increase in operating current, and achieve high reliability.

In general, it is effective to monolithically form two semiconductor lasers on one semiconductor substrate in order to narrow the interval between two laser beams. However, since it is necessary to select the end face reflectivity with respect to the laser light wavelength, it is difficult to make a two-wavelength high-power semiconductor laser that emits mutually different laser lights monolithic. However, the required accuracy of device structure parameters such as the width of the optical waveguide is strict, and there is a tendency that the yield is reduced when the device is made monolithic.

An object of the present invention is to provide a multi-beam integrated optical unit capable of narrowing a light beam interval in a multi-beam integrated optical unit that radiates to the outside. It is another object of the present invention to provide a multi-beam integrated optical unit that can incorporate a plurality of semiconductor laser elements having different wavelengths and light outputs and can narrow a light beam interval. Another object of the present invention is to provide a suitable multi-beam integrated optical unit that constitutes an optical pickup mechanism of an optical disk device. Another object of the present invention is to provide a multi-beam integrated optical unit serving as a light source for a printer that can increase the printing speed of a laser beam printer. It is another object of the present invention to provide a multi-beam integrated optical unit that can achieve a reduction in manufacturing cost. The above and other objects and novel features of the present invention will become apparent from the description of the present specification and the accompanying drawings.

[0017]

The following is a brief description of an outline of typical inventions disclosed in the present application.

(1) A plurality of reflective surfaces formed on the main surface side of the semiconductor substrate, the surfaces being different from each other, and fixed to the main surface side of the semiconductor substrate, respectively. A light-emitting element that emits laser light and / or a light-receiving element that receives light reflected by each of the reflection surfaces, and the position and directionality of the semiconductor substrate and the reflection surface are reflected by the reflection surface. The laser beams moving away from the semiconductor substrate are set to travel in the same direction. The distance between the laser beams reflected by the reflection surface is shorter than the width of the end face of the semiconductor laser device including the emission surface for emitting the laser beam.

(2) A plurality of semiconductor laser elements whose emitted laser light is used as a laser light for irradiating the optical disk surface of an optical disk device and have different laser light wavelengths, and a reflected laser light reflected by the optical disk surface. A multi-beam integrated optical unit having a plurality of light receiving elements for receiving light, wherein a semiconductor substrate, the plurality of semiconductor laser elements fixed to a main surface side of the semiconductor substrate, and the surfaces of the semiconductor substrate are different from each other. A plurality of reflection surfaces formed on the main surface side, and the position and directionality of the reflection surface and each semiconductor laser element are such that laser light emitted from each semiconductor laser element is reflected by the reflection surface. It is set so that it can be used as laser light for irradiating the optical disk surface.
The reflection surface and the semiconductor laser element are provided two each, and the laser light wavelength of one semiconductor laser element is 65
0 nm band, the laser light wavelength of the other semiconductor laser device is 780 nm band, and the laser light is divided into a plurality of laser lights in the middle of the optical path between each reflection surface and the optical disk surface. A hologram element having a diffraction grating that converges as spot light on the optical disk surface and a hologram pattern that distributes and reaches the plurality of light receiving elements reflected laser light reflected by the disk surface is provided. The distance between the laser beams reflected by the reflection surface is shorter than the width of the end face of the semiconductor laser device including the emission surface for emitting the laser beam.

(3) A multi-beam integrated optical unit having a plurality of semiconductor laser elements used as laser light emitted from a laser beam printer to a photosensitive drum of a laser beam printer in plural rows. When,
A plurality of semiconductor laser elements fixed to the main surface side of the semiconductor substrate, and a plurality of reflection surfaces having different surfaces and formed on the main surface side of the semiconductor substrate; The position and directionality of the elements are set so that the laser light emitted from each semiconductor laser element is reflected by the reflection surface and sequentially emitted in parallel. The distance between the laser beams reflected by the reflection surface is shorter than the width of the end face of the semiconductor laser device including the emission surface for emitting the laser beam.

According to the means (1), a plurality of reflection surfaces having different surfaces are provided on the main surface side of the semiconductor substrate. Therefore, (a) each laser beam (laser beam) emitted from each semiconductor laser element is reflected by a different reflecting surface and emitted to the outside in the same direction from the main surface side of the semiconductor substrate. Therefore, by selectively setting the position and directionality of each reflection surface and each semiconductor laser element, the interval between the laser beams emitted from the reflection surface to the outside can be made smaller than the chip width of the semiconductor laser element. it can.
And the interval can be made as small as 20 μm or less.

(B) using the reflection surface, to reflect light from the outside toward the main surface of the semiconductor substrate on the reflection surface and to guide the light to the light receiving element fixed on the main surface of the semiconductor substrate; Can be.

(C) Since the light-emitting element and the light-receiving element mounted on the semiconductor substrate can be mounted as independent optical elements, light-emitting elements having different wavelengths and light outputs of emitted light,
It is also possible to mount light receiving elements having different light receiving wavelength ranges, and it is possible to reduce the cost of the multi-beam integrated optical unit since an optimal design can be realized.

According to the means (2), (a) the laser light (laser beam) emitted from the two semiconductor laser elements is reflected by each reflecting surface to change the optical path. The interval between the two laser beams reflected by the reflection surface can be made close to an interval significantly smaller than the chip width of the semiconductor laser device, for example, 20 μm or less.

(B) Therefore, the effective area of the collimator lens for condensing the laser light reflected by the reflection surface can be reduced, the size of the collimator lens can be reduced, and the cost of the optical disk device can be reduced.

(C) Since the semiconductor laser elements mounted on the semiconductor substrate can be mounted in an independent optical element state, it is possible to mount semiconductor laser elements having different wavelengths and light outputs of the emitted light, and to achieve an optimal design. This makes it possible to reduce the cost of the multi-beam integrated optical unit.

According to the means of (3), the laser beams of the plurality of semiconductor laser elements are parallelly arranged using the plurality of reflection surfaces formed on the main surface side of the semiconductor substrate and are parallel light beams having an interval of 10 μm or less. When used as a light source for a laser beam printer, a single scan of the photosensitive drum can irradiate multiple laser beams (laser beams) onto the photosensitive drum, increasing the print width and printing. Speed can be increased.

[0028]

Embodiments of the present invention will be described below in detail with reference to the drawings. In all the drawings for describing the embodiments of the present invention, components having the same functions are denoted by the same reference numerals, and their repeated description will be omitted.

(Embodiment 1) FIGS. 1 to 7 relate to a multi-beam integrated optical unit according to an embodiment (Embodiment 1) of the present invention. In the first embodiment, an example in which the multi-beam integrated optical unit of the present invention is applied to an optical pickup mechanism of an optical disk device will be described.

FIG. 1 shows a multi-beam integrated optical unit 39.
1 schematically shows a substrate inside, for example, a semiconductor substrate 1, a hologram pattern 32, a collimating lens 40, a rotary actuator 41, and an optical disk 60 which constitute an optical system of an optical pickup mechanism disposed on the semiconductor substrate 1. FIG. The rotation of the optical disk 60 is controlled around a rotation center (not shown). The optical disc 60 is provided with pits 61. The pits 61 are provided along the tracks and store various information.

The rotary actuator 41 is provided with a CD objective lens 42 and a DVD objective lens 43, and the center is supported by a rotary shaft 44.
The CD objective lens 42 narrows down the 780 nm band laser light and converges it on the optical disk 60 to obtain a spot light. The DVD objective lens 43 narrows down the 650 nm band laser light and converges it on the optical disk 60 to obtain a spot light. Is to be obtained. The switching operation between the two objective lenses is performed by rotating the rotation shaft 44 by a predetermined angle.
In the first embodiment, since both objective lenses are arranged point-symmetrically with respect to the rotation axis 44, the objective lenses can be switched by rotating the rotation axis 44 by 180 degrees.

When the laser beam having passed the hologram pattern 32 and the collimating lens 40 has a wavelength of 650 μm, the rotary actuator 4
When the laser beam has a wavelength of 780 nm when the laser beam is focused on the recording surface (pit 61) of the optical disc 60 by the switching operation of 1 and the objective lens for CD, The light is stopped down at 42 and focused on the recording surface (pit 61) of the optical disk 60.

The main surface 12 of the semiconductor substrate 1 inside the multi-beam integrated optical unit 39 is provided with a depression 2 which is lowered by one step, and two semiconductor laser elements (semiconductor laser chips) are provided on the bottom surface 4 of the depression 2. 3a and 3b are fixed side by side so that extensions of the respective optical waveguides (resonators) 5a and 5b intersect. Semiconductor laser device 3
a is a semiconductor laser (LD) having an oscillation wavelength of 780 nm for reading a CD, and the semiconductor laser element 3b is a semiconductor laser having an oscillation wavelength of 650 nm for a DVD.

The bottom surface 4 of the depression 2 is a plane parallel to the main surface 12 and is the same as the crystal plane. Therefore, the laser beams (laser beams) 7a and 7b emitted from the emission surfaces of the semiconductor laser chips 3a and 3b are emitted in parallel with the main surface 12, and the forward emission light intersects when there is no obstacle. Become. However, in the first embodiment, the forward emission light is
The light is not crossed as a result of being reflected by a reflecting surface described later, and is emitted in a direction away from the main surface 12.

A triangular projecting portion 11 is provided from a part of the inner peripheral wall surface of the recess 2. The two sides of the triangular overhanging portion 11 are reflection surfaces 6a and 6b, respectively, which are inclined (for example, 45 degrees). Laser beams (laser beams) 7a, 7 emitted from the front emission surfaces of the optical waveguides 5a, 5b of the semiconductor laser chips 3a, 3b.
b is reflected and emitted upward on the main surface side of the semiconductor substrate 1.

In the first embodiment, a silicon plate is used as the semiconductor substrate 1. Each surface of the silicon substrate 1, the reflection surfaces 6a, 6b and the semiconductor laser chips 3a, 3b
Is shown in more detail in FIGS.

As shown in FIGS. 2 and 4, the semiconductor substrate 1
The principal surface 12 of [1] is [1] from the (001) plane of the silicon crystal.
00] direction as a rotation axis [010] direction (see FIG. 4)
At an angle θ (eg, θ = 15 degrees).

The two sides of the protruding portion 11 having a triangular shape on the front emission surface are inclined reflection surfaces 6a and 6b, respectively. The reflecting surface 6a is a (111) surface, and the reflecting surface 6b is a (11) surface.
1) It is a face. In addition, the optical waveguides (resonators) 5a, 5 with respect to the line 13 that divides the triangular projecting portion 11 into two parts.
The angle φ formed by b is, for example, 54.73 deg (more precisely, co
sφ = 1 / (3) ^1/2 ) (see FIG. 3), and the laser beams (laser beams) 7a, 7b emitted from the front emission surfaces of the semiconductor laser chips 3a, 3b are converted into triangular portions of the overhang portion 11. The reflecting surfaces 6a and 6b with inclined side surfaces emit light in a direction perpendicular to the main surface 12 and away from the main surface 12.

The two sides of the projecting portion 11 extending in the direction intersecting each other are used as inclined reflecting surfaces 6a and 6b, and the reflecting surfaces 6a and 6b
a, 3b are radiated in a direction away from the main surface 12 of the semiconductor substrate 1 and in a direction perpendicular to the main surface 12, so that the reflection surfaces 6a, 6b
The interval between the laser beams 7a and 7b reflected and emitted by the laser beam can be set to, for example, 20 μm or less. Therefore, it is possible to use the collimator lens 40 having a small effective area, thereby reducing the manufacturing cost of the optical pickup mechanism, and achieving downsizing of the optical system of the optical pickup.

The pattern, size, etc. of the depression 2 and the reflection surfaces 6a, 6b are freely formed by forming a predetermined etching mask on the main surface of the semiconductor substrate 1 and etching using an etching solution such as KOH. it can.

On the principal surface 12 around the depression 2 of the semiconductor substrate 1, a monitoring light receiving element (photodiode) PD for reading information from the optical disk, and a divided light receiving element for detecting a focus error, a tracking error, and the like. Elements (photodiodes for signal detection) PD1 to PD6, an integrated circuit (IC) 9 including an amplifier circuit connected to an output stage of the divided light receiving element, and an electrode pad 10 are provided.

A patterned conductor layer (not shown) is provided on the main surface 12 of the semiconductor substrate 1, the bottom surface 4 of the depression 2, and the slope connecting them. The conductor layer forms a fixing portion for fixing the electrode pad 10 and the semiconductor laser chips 3a and 3b, and furthermore, a wiring. Therefore, the electrode pad 10 and each electrode of each element are electrically connected by these wirings. Also,
The semiconductor laser chips 3a and 3b are, for example, vertically (depth) along the extending direction of the optical waveguide (resonator).
Has a length of 600 μm, a width of 300 μm, and a thickness of 100
It is made of a rectangular body having a thickness of μm, and an electrode serving as an anode electrode or a cathode electrode is provided on the upper surface or the lower surface.

FIG. 5 is a schematic diagram showing a DVD system in which a multi-beam integrated optical unit 39 is arranged below a collimating lens 40. As shown in FIG. 6, the multi-beam integrated optical unit 39 has an appearance in which a plurality of leads 23 project from both sides of a package 20 formed of a flat rectangular body. FIG. 7 is a perspective view in which the cap 22 constituting the package 20 is removed so that the inside of the package body 21 can be seen.

As shown in FIG. 7, the package body 21 has a box shape having a peripheral wall 25 and an open top, and the semiconductor substrate 1 on which the semiconductor laser chips 3a and 3b are mounted as described above is provided at the center of the inner bottom. Fixed. The leads 23 are insulatively fixed to the pair of peripheral walls 25 facing each other through an insulator 26 in a penetrating state. Further, an inner end portion protruding inside the peripheral wall 25 of the lead 23 and a corresponding electrode pad 10 (see FIG. 2) of the semiconductor substrate 1 are electrically connected by a conductive wire 27. In FIG.
For the sake of simplicity, the components such as the semiconductor laser chips 3a and 3b fixed to the main surface of the semiconductor substrate 1 will not be denoted by reference numerals.

Two leads 23 are used as independent electrodes of the two semiconductor laser chips 3a and 3b, and the integrated circuit (I
C) One is used for nine independent electrodes, six are used for independent electrodes of the divided light-receiving elements for detection PD1 to PD6, one is used as a common electrode for each element and the like, and a total of 10 leads 23 are used.
Become a book.

The cap 22 has a cap frame 30 on the frame,
The cap frame 30 is formed of a transparent glass plate 31 fixed to hermetically close the cap frame 30, and the cap frame 30 is attached so as to hermetically close the opening of the package body 21.

At the center of the inner surface of the glass plate 31, a reflected laser beam 8 reflected on the surface of the optical disk 60 (see FIG. 1)
Is provided to each of the plurality of light receiving elements (monitoring light receiving element PD and detection divided light receiving elements PD1 to PD6). A hologram pattern 32 is provided on a glass plate 31 to form a hologram element. Therefore, the hologram element is connected to each of the reflection surfaces 6a, 6b and the optical disk 60.
It will be provided in the middle of the optical path between the surface.

The laser beams 7a and 7b pass through the hologram pattern 32 and are converted into parallel light by the collimator lens 40, and then are focused on the optical disk 60 by the CD objective lens 42 or the DVD objective lens 43.

The reflected laser light 8 modulated by the pits 61 of the optical disk 60 is transmitted through the CD objective lens 42 or the DVD objective lens 43, then is diffracted by the hologram pattern 32, and is divided by the detection light receiving element (signal detection). (Photodiodes for use) PD1 to PD6.

A necessary signal is obtained from each output of the divided light receiving elements PD1 to PD6 for detection. That is, the focus error signal is obtained by subtracting the sum of PD2, PD4, and PD6 from the sum of the signals of the detection light-receiving elements PD1, PD3, and PD5, and the tracking error signal is the sum of the detection light-receiving elements PD1 and PD4. Is obtained by subtracting the sum of the signals of PD3 and PD6 from the above, and the reproduced signal is obtained by the sum of the signals of the divided photodetectors PD2 and PD5.

Since the signals of PD1 to PD6 are weak, they are easily affected by noise. Therefore, the built-in integrated circuit (I
C) 9 amplifies these signals. In some cases, the IC 9 can also calculate the signals of the PD1 to PD6 for extracting the focus error signal, the tracking error signal, and the reproduction signal.

According to the first embodiment, the following effects can be obtained. (1) The laser beams 7a and 7b emitted from the two semiconductor laser elements 3a and 3b are reflected by reflection surfaces 6a and 6b having different surfaces.
6b, the distance between the two laser beams 7a, 7b reflected by the reflecting surfaces 6a, 6b is set to be equal to that of the semiconductor laser devices 3a, 3b. Spacing, which is significantly smaller than the chip width of
For example, it can be close to 20 μm or less. Therefore, a multi-beam integrated optical unit having a narrow laser beam (light beam) interval can be provided.

(2) In a multi-beam integrated optical unit in which the interval between the two laser beams 7a and 7b radiated from the reflecting surfaces 6a and 6b is close to, for example, 20 μm or less, when used in an optical pickup mechanism of an optical disk device, The use of the collimating lens 40 having a small effective area becomes possible.
As a result, a lower cost collimating lens 40 can be used, and the manufacturing cost of the optical disk device can be reduced.

(3) The size of the optical pickup mechanism can be reduced by using the collimating lens 40 having a small effective area. As a result, the cost of the optical disk device can be reduced.

(4) Since the semiconductor laser elements 3a and 3b mounted on the semiconductor substrate 1 are each equipped with an independent optical element, it is possible to mount semiconductor laser elements having different wavelengths and light outputs of emitted light. Design becomes possible. As a result, it is possible to provide a multi-beam integrated optical unit in which a plurality of semiconductor laser elements having different wavelengths and different optical outputs are built and the light beam interval is narrow.

(5) When the multi-beam integrated optical unit is used for the optical pickup mechanism of the optical disk device,
Laser beams 7a and 7b having wavelengths corresponding to the D objective lens 42 and the DVD objective lens 43 can be easily emitted by switching the semiconductor laser elements 3a and 3b. Also, the built-in semiconductor laser elements 3a and 3b emit laser beams 7a and 7b toward different reflecting surfaces 6a and 6b, respectively.
, The structure of the multi-beam integrated optical unit can be simplified and the cost can be reduced. That is, it is possible to provide a suitable multi-beam integrated optical unit constituting the optical pickup mechanism of the optical disk device.

(6) In the multi-beam integrated optical unit, by setting the interval between the two laser beams 7a and 7b to, for example, 10 μm or less, it can be used as a light source of a laser beam printer. In this case, by arranging and scanning the two laser beams 7a and 7b on the photosensitive drum, the printing width can be increased, and the printing speed (printing speed) can be increased. In this case, a light receiving element, an integrated circuit, and the like are not required as in the embodiment described later.

(Embodiment 2) FIGS. 8 to 10 relate to a multi-beam integrated optical unit according to another embodiment (Embodiment 2) of the present invention. FIG. 8 shows a part of the multi-beam integrated optical unit. FIG. 9 is a schematic cross-sectional view showing the relationship between a substrate in a multi-beam integrated optical unit and a reflection surface or a semiconductor laser element provided on the substrate, and FIG. FIG. 3 is a schematic plan view showing a layout of an element.

As shown in FIGS. 8 to 10, the multi-beam integrated optical unit according to the second embodiment differs from the structure according to the first embodiment in that the recess 2 provided in the main surface 12 of the semiconductor substrate 1 is formed.
Is a simple rectangular pattern, and two semiconductor laser elements 3a and 3b are provided on the bottom surface 4 of the depression 2 so that their front emission surfaces face each other and an optical waveguide (resonator).
5a and 5b are arranged so as to be shifted by a predetermined distance (e), and the reflecting surfaces 6a and 6b are arranged between the front emission surfaces of the two.

One reflecting surface 6a has a 45 ° inclination with respect to the bottom surface 4 of the depression 2, and the other reflecting surface 6b has a structure having a 135 ° inclination with respect to the bottom surface 4. The semiconductor laser element 3a , 3b, the laser beams (laser beams) 7a, 7b emitted from the front emission surfaces, which are one ends of the optical waveguides (resonators) 5a, 5b, are reflected by the reflection surfaces 6a, 6b, respectively. Is radiated in a direction perpendicular to and away from the light. Reflecting surfaces 6a, 6
b can be freely formed in size and height by etching the main surface 12 side of the semiconductor substrate 1 made of silicon in a predetermined state.

The interval (e) can be freely set including zero. As a result, the laser beams 7a and 7b emitted from the reflecting surfaces 6a and 6b can be brought close to several tens μm or less, and the same effect as the multi-beam integrated optical unit of the first embodiment can be obtained.

(Embodiment 3) FIGS. 11 to 13 relate to a multi-beam integrated optical unit according to another embodiment (Embodiment 3) of the present invention. FIG. 11 shows a part of the multi-beam integrated optical unit. FIG. 12 is a schematic cross-sectional view showing the relationship between a substrate in the multi-beam integrated optical unit and a reflection surface or a semiconductor laser device provided on the substrate, and FIG. 13 is a schematic view showing the reflection surface and the semiconductor laser device. FIG. 3 is a schematic plan view showing the layout of FIG. Embodiment 3
According to the second embodiment, in the second embodiment, the reflecting surfaces 6a and 6b are formed by independent optical components 15a and 15b.
5a and 15b are positioned and fixed to the bottom surface 4 of the recess 2. Each of the optical components 15a and 15b has one surface inclined, and the inclined surfaces are used as reflection surfaces 6a and 6b. The reflecting surfaces 6a, 6b are separate optical components 15a, 15
Since b is formed side by side, the distance between the reflection points of the laser beams 7a and 7b on the reflection surfaces 6a and 6b cannot be made zero, but it is easy to make it as narrow as 20 μm or less. The third embodiment can obtain the same effects as those of the multi-beam integrated optical unit of the first embodiment.

(Embodiment 4) FIG. 14 is a schematic view showing a part of a multi-beam integrated optical unit according to another embodiment (Embodiment 4) of the present invention. In the fourth embodiment, four semiconductor laser elements 3a, 3b, 3c, 3 arranged so as to emit laser beams (laser beams) 7a, 7b, 7c, 7d from four directions (cross-shaped direction) toward the center, respectively.
The configuration is such that a quadrangular pyramid-shaped optical component 16 is arranged at the center of d. The four inclined surfaces of the quadrangular pyramid are reflection surfaces, and the laser beams 7a, 7b, 7c, 7d emitted from the respective semiconductor laser elements 3a, 3b, 3c, 3d are reflected by the reflection surface 6a.
And is radiated perpendicularly to the main surface of the semiconductor substrate (not shown) and away from the main surface.

By changing the height of the quadrangular pyramid, each of the laser beams 7a, 7b, 7c,
The positional relationship of 7d changes, and the larger the square pyramid, the larger the interval between the laser beams 7a, 7b, 7c, 7d, and the smaller the square pyramid, the smaller the interval between the laser beams 7a, 7b, 7c, 7d.

Each of the semiconductor laser elements 3a, 3b, 3c, 3
d can all be of the same characteristics,
It is possible to use different or different wavelengths or light outputs in part or all, and it is possible to adapt to the use state of the multi-beam. Such a multi-beam integrated optical unit becomes, for example, a 4-beam multi-beam LD, and can be used as a light source of a high-speed laser beam printer (LBP). The quadrangular pyramid may be an independent optical component, or may be formed by etching silicon.

(Embodiment 5) FIG. 15 is a schematic view showing a part of a multi-beam integrated optical unit according to another embodiment (Embodiment 5) of the present invention. In the fifth embodiment, the light receiving element 17 is arranged so as to correspond to one of the quadrangular pyramid reflecting surfaces 6 in the fourth embodiment, and the semiconductor laser elements 3a and 3a are disposed on the remaining three surfaces of the quadrangular pyramid reflecting surface 6. 3b and 3c are arranged correspondingly. In this configuration, the three laser beams 7a, 7b, and 7c are emitted, and the light intensity of the reflected light, for example, the reflected light 18 can be monitored by the light receiving element 17. Such a multi-beam integrated optical unit can be used, for example, for returning a part of the light emitted from an LD on a multi-beam optical disc or the like and stabilizing the light output by front light monitored by one PD. In the fifth embodiment, the number and arrangement of light receiving elements and semiconductor laser elements can be freely set.

(Embodiment 6) FIGS. 16 to 18 are diagrams relating to a multi-beam integrated optical unit according to another embodiment (Embodiment 6) of the present invention. In the sixth embodiment, an example in which the multi-beam integrated optical unit 39 is used as a light source of a laser beam printer will be described. The multi-beam integrated optical unit 39 according to the sixth embodiment is configured to emit, for example, two laser beams 7a and 7b in parallel at an interval of 10 μm or less.

FIG. 16 is a schematic diagram showing a part of a laser beam printer. The two laser beams 7a and 7b emitted from the multi-beam integrated optical unit 39 pass through a collimating lens 70, are reflected by a polygon mirror 71, pass through a collimating lens 72 and an aspheric lens (fθ lens) 73, and are exposed to light. Irradiation is performed on the drum 74 as two laser beams 7a and 7b which are arranged in parallel. As a result, an electrostatic latent image is formed on the photosensitive drum 74 by the two laser beams 7a and 7b at an interval of 10 μm or less.

Since the electrostatic latent image is formed by two laser beams 7a and 7b having a small interval, the width of the electrostatic latent image for scanning the photosensitive drum 74 at one time is widened. The printing area per one scan of the printer is increased, and the printing speed is increased.

Further, since the interval between the laser beams 7a and 7b applied to the photosensitive drum 74 is as narrow as 20 μm or less, it is possible to form a high-definition electrostatic latent image and to perform high-definition printing. By further increasing the number of laser beams, it is possible to further increase the printing area per scanning and to increase the printing speed.

FIG. 17 is a perspective view showing an appearance of a multi-beam integrated optical unit used as a light source of a laser beam printer, and FIG. 18 is a perspective view showing a state where a cap of the multi-beam integrated optical unit is opened.

The multi-beam integrated optical unit 39 of the sixth embodiment need only emit two laser beams 7a and 7b, and does not need to detect reflected light. As shown, it has a simple structure.

That is, the depression 2 for mounting the two semiconductor laser elements 3a and 3b is formed on the main surface 12 of the semiconductor substrate 1.
And a point that reflection surfaces 6a and 6b that reflect laser beams 7a and 7b emitted from two semiconductor laser elements 3a and 3b fixed to the bottom surface 4 of the depression 2 are provided. There are light-receiving elements and integrated circuits (I
C) is not provided. As in the first embodiment, the reflecting surfaces 6a and 6b are formed such that a part of the peripheral wall of the depression 2 projects in a triangular shape, and the inclined side surfaces of the projecting portion 11 are the reflecting surfaces 6a and 6b.

As shown in FIG. 18, the upper electrodes of the semiconductor laser elements 3 a and 3 b fixed to the bottom surface 4 of the depression 2 of the semiconductor substrate 1 are electrically connected to predetermined leads 23 by wires 27. Further, two electrode pads 10 provided on the main surface 12 of the semiconductor substrate 1 and predetermined leads 23 are electrically connected by wires 27. One of the electrode pads 10 is electrically connected to the lower electrode of one semiconductor laser element 3a, and the other is electrically connected to the lower electrode of the other semiconductor laser element 3b. This allows the semiconductor laser element 3a and the semiconductor laser element 3b to be used independently.

In the sixth embodiment, no hologram element is formed on the cap 22 constituting the package 20. In FIGS. 17 and 18, four leads 23 projecting from the package 20 protrude from both sides, respectively. However, the present invention is not particularly limited to this.

Although the invention made by the inventor has been specifically described based on the embodiment, the invention is not limited to the above embodiment, and various modifications can be made without departing from the gist of the invention. Needless to say.

[0077]

The effects obtained by the representative ones of the inventions disclosed in the present application will be briefly described as follows. (1) In the multi-beam integrated optical unit, the interval between a plurality of light beams to be emitted can be reduced to, for example, 20 μm or less. (2) In a structure in which a plurality of reflection surfaces are provided, a plurality of light beams can be emitted at narrow intervals. (3) In a structure in which a plurality of reflecting surfaces are provided, a plurality of light beams can be emitted at narrow intervals, and light from the outside can be received by using some of the reflecting surfaces. (4) It is possible to provide a multi-beam integrated optical unit in which a plurality of semiconductor laser elements having different wavelengths and light outputs can be built in and the light beam interval can be reduced. (5) It is possible to provide a suitable multi-beam integrated optical unit that constitutes an optical pickup mechanism of an optical disk device capable of reading and writing CD-R and DVD. (6) It is possible to provide a multi-beam integrated optical unit serving as a printer light source capable of increasing the printing speed of a laser beam printer. (7) The manufacturing cost of the multi-beam integrated optical unit can be reduced by simplifying the configuration.

[Brief description of the drawings]

FIG. 1 is a schematic diagram in which a multi-beam integrated optical unit according to an embodiment (Embodiment 1) of the present invention is applied to an optical pickup mechanism of an optical disk device.

FIG. 2 is a schematic perspective view showing a substrate in the multi-beam integrated optical unit and a reflection surface, a semiconductor laser device, and the like provided on the substrate.

FIG. 3 is a schematic plan view showing a layout of the reflection surface and a semiconductor laser device.

FIG. 4 is a schematic sectional view showing a positional relationship between the reflection surface and a semiconductor laser device.

FIG. 5 is a partial schematic diagram in which the multi-beam integrated optical unit according to the first embodiment is applied to an optical pickup mechanism of an optical disk device.

FIG. 6 is a perspective view illustrating an appearance of the multi-beam integrated optical unit according to the first embodiment.

FIG. 7 is a perspective view showing a state where a cap of the multi-beam integrated optical unit is opened.

FIG. 8 is a schematic diagram in which a multi-beam integrated optical unit according to another embodiment (Embodiment 2) of the present invention is applied to an optical pickup mechanism of an optical disk device.

FIG. 9 is a schematic cross-sectional view showing the relationship between a substrate in the multi-beam integrated optical unit and a reflection surface, a semiconductor laser device, and the like provided on the substrate.

FIG. 10 is a schematic plan view showing a layout of the reflection surface and the semiconductor laser device.

FIG. 11 is a schematic diagram in which a multi-beam integrated optical unit according to another embodiment (Embodiment 3) of the present invention is applied to an optical pickup mechanism of an optical disk device.

FIG. 12 is a schematic cross-sectional view showing a relationship between a substrate in the multi-beam integrated optical unit and a reflection surface, a semiconductor laser device, and the like provided on the substrate.

FIG. 13 is a schematic plan view showing a layout of the reflection surface and the semiconductor laser device.

FIG. 14 is a schematic view showing a part of a multi-beam integrated optical unit according to another embodiment (Embodiment 4) of the present invention.

FIG. 15 is a schematic view showing a part of a multi-beam integrated optical unit according to another embodiment (Embodiment 5) of the present invention.

FIG. 16 is a schematic diagram in which a multi-beam integrated optical unit according to another embodiment (Embodiment 6) of the present invention is applied to a light source of a laser beam printer.

FIG. 17 is a perspective view illustrating an appearance of a multi-beam integrated optical unit according to a sixth embodiment.

FIG. 18 is a perspective view showing a state where a cap of the multi-beam integrated optical unit is opened.

FIG. 19 is a schematic perspective view showing a substrate in the multi-beam integrated optical unit and a reflection surface, a semiconductor laser element, and the like provided on the substrate.

FIG. 20 is a schematic view showing a part of a multi-beam integrated optical unit studied by the present inventors.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Substrate (semiconductor substrate), 2 ... depression, 3a, 3b, 3
c, 3d: semiconductor laser element (semiconductor laser chip),
4: bottom surface, 5a, 5b: optical waveguide (resonator), 6, 6
a, 6b: reflective surface, 7a, 7b, 7c, 7d: laser light (laser beam), 8: reflected laser light, 9: integrated circuit (IC), 10: electrode pad, 11: projecting portion, 12 ...
Main surface, 13 ... line, 15a, 15b ... optical component, 16 ... optical component, 17 ... light receiving element, 18 ... reflected light, 20 ... package, 21 ... package body, 22 ... cap, 23 ...
Lead, 25: peripheral wall, 26: insulator, 27: wire, 3
0: cap frame, 31: glass plate, 32: hologram pattern, 39: multi-beam integrated optical unit, 40:
Collimating lens, 41 ... rotary actuator, 42 ...
CD objective lens, 43 ... DVD objective lens, 44 ...
Rotation axis, 60 optical disk, 61 pit, 70 collimating lens, 71 polygon mirror, 72 collimating lens, 73 aspheric lens (fθ lens), 74
Photosensitive drum.

Continued on front page F term (reference) 2C362 AA11 AA14 AA43 AA45 AA47 BA56 BA58 BA61 BA83 BA87 DA03 5D119 AA41 BA01 CA10 CA16 DA01 DA05 EA02 EA03 EC45 EC46 EC47 FA08 FA36 JA14 JA57 JA64 LB07 NA04 NA05 NA06 5F073 AB06 AB15 AB25 AB15 BA07 DA23 FA03 FA06 FA13 FA16 FA23 5F089 AA02 AB01 BA04 BB01 BC02 BC04 BC07 BC08 BC16 BC23 BC24 BC25 BC29 GA05

Claims (5)

[Claims] 1. A semiconductor substrate, a plurality of reflecting surfaces having surfaces different from each other and formed on a main surface side of the semiconductor substrate, and a plurality of reflecting surfaces fixed to the main surface side of the semiconductor substrate, respectively, facing each of the reflecting surfaces. A light-emitting element that emits laser light and / or a light-receiving element that receives light reflected by each of the reflection surfaces; and the position and directionality of the semiconductor substrate and the reflection surface are reflected by the reflection surface. A multi-beam integrated optical unit, wherein laser beams moving away from a semiconductor substrate are set to travel in the same direction. 2. A plurality of semiconductor laser elements, each of which emits laser light as laser light for irradiating an optical disk surface of an optical disk device, and receives a reflected laser light reflected by the optical disk surface. A multi-beam integrated optical unit having a plurality of light receiving elements, wherein: a semiconductor substrate; and the plurality of semiconductor laser elements fixed to a main surface side of the semiconductor substrate; A plurality of reflection surfaces formed on the surface side, wherein the position and directionality of the reflection surface and each semiconductor laser element are:
A multi-beam integrated optical unit, which is set so that laser light emitted from each semiconductor laser element is reflected by the reflection surface and can be used as laser light for irradiating the optical disk surface. 3. The semiconductor laser device according to claim 2, wherein the reflecting surface and the semiconductor laser device are provided two each.
A diffraction grating that divides the laser light into a plurality of laser lights and converges the laser light as a spot light on the optical disk surface, in the middle of an optical path between each of the reflection surfaces and the optical disk surface; 3. The multi-beam integrated optical unit according to claim 2, further comprising a hologram element having a hologram pattern for distributing the reflected laser light reflected by the hologram to the plurality of light receiving elements. 4. A multi-beam integrated optical unit having a plurality of semiconductor laser elements used as laser light emitted from a plurality of rows of laser beams emitted from a laser beam to a photosensitive drum of a laser beam printer, comprising: a semiconductor substrate; A plurality of semiconductor laser elements fixed to the main surface side of the semiconductor substrate; and a plurality of reflection surfaces formed on the main surface side of the semiconductor substrate, the surfaces being different from each other; The position and directionality of the laser element
A multi-beam integrated optical unit, wherein laser light emitted from each of the semiconductor laser elements is set to be reflected by the reflection surface and sequentially emitted in parallel. 5. The semiconductor laser device according to claim 1, wherein an interval between the laser beams reflected by the reflection surface is smaller than a width of an end surface of the semiconductor laser device including an emission surface for emitting laser light. The multi-beam integrated optical unit according to any one of claims 1 to 4.