JP2011119496A - Optical device, optical scanner, image forming apparatus, and manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical device capable of emitting stable light with small variation in light quantity without any rise in cost. <P>SOLUTION: A cover glass 300 is fixed to a package member 200 at a tilt angle of 17° with respect to an emission surface of a laser chip, with an inexpensive resin-based adhesive. Then a part of a portion of the package member 200 where the cover glass 300 is supported is not coated with the adhesive. In this case, even when an inexpensive non-reflective glass plate is used as the cover glass 300, return light is prevented from entering an active layer of the laser chip. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an optical device, an optical scanning device, an image forming apparatus, and a manufacturing method, and more specifically, an optical device in which a surface emitting laser element is held by a package member, an optical scanning device having the optical device, and the light The present invention relates to an image forming apparatus including a scanning device and a method for manufacturing the optical device.

  In general, when a laser element that emits laser light is used together with an optical system, light reflected from the surface of a lens or glass included in the optical system is incident as return light, and the amount of light in the emitted laser light varies. There was a risk of causing it. Therefore, a laser element having high resistance to return light has been proposed.

  For example, in Patent Document 1, a resonator is formed by a lower multilayer reflector and an upper multilayer reflector, and a relaxation oscillation frequency at a bias point in the resonator is a laser beam output from a surface emitting laser element. A surface emitting laser element that is set to exceed the optical communication frequency to be modulated is disclosed.

  Patent Document 2 discloses a semiconductor substrate, an active layer provided above the semiconductor substrate, and an emission that is provided above the active layer and emits laser light generated in the active layer in a direction perpendicular to the semiconductor substrate. A surface-emitting semiconductor laser including a surface and an absorption layer provided on the emission surface and absorbing part of the laser light is disclosed.

  It was also devised to suppress the return light itself.

  For example, Patent Document 3 discloses an optical transmission surface having a cap provided with a window on which a surface-emitting laser chip and a monitor photodetector are mounted on a TO header and a film having a transmittance of 40% or less is coated. A light emitting laser module is disclosed.

  By the way, in recent years, the demand for stability of laser light emitted from a laser element has become strict, and it has been difficult for the laser elements and laser modules described in Patent Documents 1 to 3 to satisfy the demand. .

  The present invention has been made under such circumstances, and a first object of the present invention is to provide an optical device that can emit stable light with little fluctuation in light amount without causing an increase in cost. .

  A second object of the present invention is to provide an optical scanning device capable of performing stable optical scanning without increasing the cost.

  A third object of the present invention is to provide an image forming apparatus capable of forming a high quality image.

From the first viewpoint, the present invention provides an optical device comprising a surface-emitting laser element and a package member that holds the surface-emitting laser element on a bottom surface of a spatial region surrounded by a wall.
The transparent member further includes a transparent member that is held on the package member and disposed on an optical path of light emitted from the surface emitting laser element, and the transparent member has a surface on which light emitted from the surface emitting laser element is incident. Inclined with respect to the emission surface of the surface emitting laser element and fixed to the package member with an adhesive, and the adhesive is applied to a portion of the package member supporting the transparent member. An optical device characterized by not.

  According to this, it is possible to emit stable light with little fluctuation in light amount without causing an increase in cost.

  According to a second aspect of the present invention, there is provided an optical scanning device that scans a surface to be scanned with light, a light source having the optical device of the present invention; a deflector that deflects light from the light source; And a scanning optical system for condensing the light deflected by the scanner on the surface to be scanned.

  According to this, since the light source has the optical device of the present invention, stable optical scanning can be performed without increasing the cost.

  According to a third aspect of the present invention, there is provided at least one image carrier; and at least one optical scanning device according to the invention that scans the at least one image carrier with light including image information. An image forming apparatus provided.

  According to this, since the optical scanning device of the present invention is provided, it is possible to form a high-quality image as a result.

  According to a fourth aspect of the present invention, there is provided a manufacturing method for manufacturing an optical device of the present invention in which a surface emitting laser element and a transparent member are held by a package member, wherein the surface emitting laser element is fixed, Placing the transparent member on the package member that is electrically connected to the surface emitting laser element; and a surface of the transparent member on which light emitted from the surface emitting laser element is incident is horizontal. And a step of inclining the package member; and a step of applying an adhesive for fixing the transparent member to the package member.

  According to this, the optical device of this invention can be manufactured efficiently.

It is a figure for demonstrating schematic structure of the laser printer which concerns on one Embodiment of this invention. It is the schematic which shows the optical scanning device in FIG. It is a figure for demonstrating the light source unit in FIG. It is a figure for demonstrating the optical device contained in the light source unit. It is AA sectional drawing of FIG. It is BB sectional drawing of FIG. It is the figure which removed the cover glass from FIG. It is a top view of a package member. It is AA sectional drawing of FIG. It is a figure for demonstrating the inclination of a cover glass. It is a figure for demonstrating a laser chip. It is a figure for demonstrating the arrangement state of the several light emission part in a laser chip. It is a figure for demonstrating the structure and structure of each light emission part. It is AA sectional drawing of FIG. It is BB sectional drawing of FIG. FIG. 16A and FIG. 16B are diagrams for explaining an inclined substrate, respectively. FIGS. 17A and 17B are views (No. 1) for describing a method of manufacturing a laser chip, respectively. FIG. 18A and FIG. 18B are views (No. 2) for describing a method of manufacturing a laser chip, respectively. It is a figure for demonstrating an etching mask. It is an enlarged view of the mesa upper surface part in FIG. FIG. 21A is a diagram (No. 3) for explaining the method of manufacturing a laser chip, and FIG. 21B is an enlarged view of a mesa upper surface portion in FIG. 22A is a diagram (part 4) for explaining the laser chip manufacturing method, and FIG. 22B is an enlarged view of the mesa upper surface portion in FIG. 22A. FIG. 23A is a view (No. 5) for explaining the method of manufacturing a laser chip, and FIG. 23B is an enlarged view of a mesa upper surface portion in FIG. FIG. 24A and FIG. 24B are diagrams for explaining a low reflectance region and a high reflectance region, respectively. It is FIG. (6) for demonstrating the manufacturing method of a laser chip. It is AA sectional drawing of FIG. FIG. 6 is a diagram (part 1) for describing an output waveform; FIG. 5 is a second diagram for explaining an output waveform; 6 is a diagram for explaining a droop rate (measured value) of each light emitting unit in the optical device A. FIG. 6 is a diagram for explaining a droop rate (measured value) of each light emitting unit in the optical device B. 6 is a diagram for explaining a droop rate (measured value) of each light emitting unit in the optical device C. FIG. 4 is a diagram for explaining a droop rate (measured value) of each light emitting unit in the optical device D. FIG. 4 is a diagram for explaining a droop rate (measured value) of each light emitting unit in the optical device E. FIG. 6 is a diagram for explaining a droop rate (measured value) of each light emitting unit in the optical device F. FIG. It is a figure (the 1) for demonstrating the holder for adhesive agent application. It is FIG. (2) for demonstrating the holder for adhesive agent application. It is a figure for demonstrating the example 1 of an adhesive agent application part. It is a figure for demonstrating the example 2 of an adhesive agent application part. 6 is a diagram for explaining an application direction in an adhesive application part of Example 1. FIG. It is a figure for demonstrating the modification 1 of a mode filter. It is a figure for demonstrating the modification 2 of a mode filter. It is a figure for demonstrating the modification 3 of a mode filter. It is a figure for demonstrating the modification 4 of a mode filter. It is FIG. (1) for demonstrating the modification of a laser chip. FIGS. 45A and 45B are diagrams for explaining a low reflectance region and a high reflectance region in a laser chip according to a modified example, respectively. It is FIG. (2) for demonstrating the modification of a laser chip. It is a figure for demonstrating schematic structure of a color printer.

  Hereinafter, an embodiment of the present invention will be described with reference to FIGS. FIG. 1 shows a schematic configuration of a laser printer 1000 according to an embodiment.

  The laser printer 1000 includes an optical scanning device 1010, a photosensitive drum 1030, a charging charger 1031, a developing roller 1032, a transfer charger 1033, a charge eliminating unit 1034, a cleaning unit 1035, a toner cartridge 1036, a paper feeding roller 1037, a paper feeding tray 1038, A registration roller pair 1039, a fixing roller 1041, a paper discharge roller 1042, a paper discharge tray 1043, a communication control device 1050, a printer control device 1060 that comprehensively controls the above-described units, and the like are provided. These are housed in predetermined positions in the printer housing 1044.

  The communication control device 1050 controls bidirectional communication with a host device (for example, a personal computer) via a network or the like.

  The photosensitive drum 1030 is a cylindrical member, and a photosensitive layer is formed on the surface thereof. That is, the surface of the photoconductor drum 1030 is a scanned surface. The photosensitive drum 1030 rotates in the direction of the arrow in FIG.

  The charging charger 1031, the developing roller 1032, the transfer charger 1033, the charge removal unit 1034, and the cleaning unit 1035 are each disposed in the vicinity of the surface of the photosensitive drum 1030. Then, along the rotation direction of the photosensitive drum 1030, the charging charger 1031 → the developing roller 1032 → the transfer charger 1033 → the discharging unit 1034 → the cleaning unit 1035 are arranged in this order.

  The charging charger 1031 uniformly charges the surface of the photosensitive drum 1030.

  The optical scanning device 1010 scans the surface of the photosensitive drum 1030 charged by the charging charger 1031 with a light beam modulated based on image information from the host device, and corresponds to the image information on the surface of the photosensitive drum 1030. A latent image is formed. The latent image formed here moves in the direction of the developing roller 1032 as the photosensitive drum 1030 rotates. The configuration of the optical scanning device 1010 will be described later.

  The toner cartridge 1036 stores toner, and the toner is supplied to the developing roller 1032.

  The developing roller 1032 causes the toner supplied from the toner cartridge 1036 to adhere to the latent image formed on the surface of the photosensitive drum 1030 to visualize the image information. Here, the latent image to which the toner is attached (hereinafter also referred to as “toner image” for the sake of convenience) moves in the direction of the transfer charger 1033 as the photosensitive drum 1030 rotates.

  Recording paper 1040 is stored in the paper feed tray 1038. A paper feed roller 1037 is disposed in the vicinity of the paper feed tray 1038, and the paper feed roller 1037 takes out the recording paper 1040 one by one from the paper feed tray 1038 and conveys it to the registration roller pair 1039. The registration roller pair 1039 temporarily holds the recording paper 1040 taken out by the paper supply roller 1037, and in the gap between the photosensitive drum 1030 and the transfer charger 1033 according to the rotation of the photosensitive drum 1030. Send it out.

  A voltage having a polarity opposite to that of the toner is applied to the transfer charger 1033 in order to electrically attract the toner on the surface of the photosensitive drum 1030 to the recording paper 1040. With this voltage, the toner image on the surface of the photosensitive drum 1030 is transferred to the recording paper 1040. The recording sheet 1040 transferred here is sent to the fixing roller 1041.

  In the fixing roller 1041, heat and pressure are applied to the recording paper 1040, whereby the toner is fixed on the recording paper 1040. The recording paper 1040 fixed here is sent to the paper discharge tray 1043 via the paper discharge roller 1042 and is sequentially stacked on the paper discharge tray 1043.

  The neutralization unit 1034 neutralizes the surface of the photosensitive drum 1030.

  The cleaning unit 1035 removes the toner remaining on the surface of the photosensitive drum 1030 (residual toner). The surface of the photosensitive drum 1030 from which the residual toner has been removed returns to the position facing the charging charger 1031 again.

  Next, the configuration of the optical scanning device 1010 will be described.

  As shown in FIG. 2 as an example, the optical scanning device 1010 includes a deflector-side scanning lens 11a, an image plane-side scanning lens 11b, a polygon mirror 13, a light source unit 14, a cylindrical lens 17, a reflection mirror 18, and scanning control. A device (not shown) is provided. These are assembled at predetermined positions of the optical housing 30.

  In this specification, the light emission direction from the light source unit 14 is described as the Z-axis direction, and two directions orthogonal to each other in a plane perpendicular to the Z-axis direction are described as the X-axis direction and the Y-axis direction. For convenience, the direction corresponding to the main scanning direction is abbreviated as “main scanning corresponding direction”, and the direction corresponding to the sub scanning direction is abbreviated as “sub scanning corresponding direction”.

  As an example, the light source unit 14 includes a laser module 500 and an optical module 600, as shown in FIG.

  The laser module 500 includes an optical device 510, a laser controller (not shown) that drives and controls the optical device 510, and a PCB (Printed Circuit Board) substrate 580 on which the optical device 510 and the laser controller are mounted. Yes.

  As shown in FIGS. 4 to 7 as an example, the optical device 510 includes a laser chip 100, a package member 200 that holds the laser chip 100, a cover glass 300, and the like.

  4 is a plan view of the optical device 510, FIG. 5 is a sectional view taken along line AA in FIG. 4, and FIG. 6 is a sectional view taken along line BB in FIG. Moreover, FIG. 7 is a figure when the cover glass 300 in FIG. 4 is removed. In FIG. 7, in order to avoid complication, the illustration of the bonding wire that connects the laser chip 100 and the package member 200 is omitted.

  As shown in FIGS. 8 and 9, the package member 200 is a flat package called CLCC (Ceramic leaded chip carrier). 9 is a cross-sectional view taken along the line AA in FIG.

  The package member 200 has a space region surrounded by a wall on the + Z side.

  Further, the package member 200 has a multilayer structure of a ceramic 201 and a plurality of metal wirings 203.

  The plurality of metal wirings 203 are individually connected to the plurality of metal casters 207 on the side surface of the package, and extend from the periphery of the package member toward the center.

  A metal film 205 is provided on the bottom surface of the space area. The metal film 205 is also called a die attach area and serves as a common electrode.

  The laser chip 100 is approximately at the center of the bottom surface of the space region, and is die-bonded on the metal film 205 using a solder material such as AuSn. That is, the laser chip 100 is held on the bottom surface of a region surrounded by a wall.

  The cover glass 300 is a rectangular transparent glass plate having a long side in the X-axis direction. Here, as shown in FIG. 10 as an example, the cover glass 300 is supported in the vicinity of the long side on the −Y side by the surface on the + Z side of the package member 200, near the long side on the + Y side, and in the X-axis direction. Near the both ends, the vicinity of the central portion in the YZ cross section is supported by the step portion of the wall in the space region. Note that one of the vicinity of the long side on the + Y side and the vicinity of both ends in the X-axis direction and the vicinity of the center in the YZ cross section may be supported by a step portion of the wall of the space region. Therefore, the surface of the cover glass 300 is inclined with respect to the Y-axis direction. Note that this inclination angle is θ. This inclination angle will be described later.

  Returning to FIG. 3, the optical module 600 includes a first portion 610 and a second portion 630. The first portion 610 includes a half mirror 611, a condenser lens 612, and a light receiving element 613. The second portion 630 includes a coupling lens 631 and an aperture plate 632.

  The first portion 610 is arranged on the + Z side of the optical device 510 so that the half mirror 611 is positioned on the optical path of the light emitted from the laser chip 100. Part of the light incident on the half mirror 611 is reflected in the −Y direction and is received by the light receiving element 613 via the condenser lens 612. The light receiving element 613 outputs a signal (photoelectric conversion signal) corresponding to the amount of received light to the laser control device of the laser module 500.

  The second portion 630 is disposed on the + Z side of the first portion 610 so that the coupling 631 is positioned on the optical path of the light transmitted through the half mirror 611. The coupling 631 converts the light transmitted through the half mirror 611 into substantially parallel light. The aperture plate 632 has an aperture and shapes the light that has passed through the coupling 631. The light that has passed through the opening of the opening plate 632 becomes light emitted from the light source unit 14.

  Returning to FIG. 2, the cylindrical lens 17 condenses the light emitted from the light source unit 14 in the vicinity of the deflection reflection surface of the polygon mirror 13 via the reflection mirror 18.

  The optical system arranged on the optical path between the laser chip 100 and the polygon mirror 13 is also called a pre-deflector optical system. In the present embodiment, the pre-deflector optical system includes a coupling lens 631, an aperture plate 632, a cylindrical lens 17, and a reflection mirror 18.

  The polygon mirror 13 is made of a regular hexagonal columnar member having a low height, and six deflecting reflection surfaces are formed on the side surface. Then, it is rotated at a constant angular velocity in the direction of the arrow shown in FIG. 2 by a rotation mechanism (not shown). Therefore, the light emitted from the light source unit 14 and condensed near the deflection reflection surface of the polygon mirror 13 by the cylindrical lens 17 is deflected at a constant angular velocity by the rotation of the polygon mirror 13.

  The deflector-side scanning lens 11 a is disposed on the optical path of the light deflected by the polygon mirror 13.

  The image plane side scanning lens 11b is disposed on the optical path of light via the deflector side scanning lens 11a. Then, the light passing through the image surface side scanning lens 11b is irradiated on the surface of the photosensitive drum 1030 to form a light spot. This light spot moves in the longitudinal direction of the photosensitive drum 1030 as the polygon mirror 13 rotates. That is, the photoconductor drum 1030 is scanned. The moving direction of the light spot at this time is the “main scanning direction”. The rotation direction of the photosensitive drum 1030 is the “sub-scanning direction”.

  The optical system arranged on the optical path between the polygon mirror 13 and the photosensitive drum 1030 is also called a scanning optical system. In the present embodiment, the scanning optical system includes a deflector side scanning lens 11a and an image plane side scanning lens 11b. Note that, on the optical path between the polygon mirror 13 and the deflector-side scanning lens 11a, on the optical path between the deflector-side scanning lens 11a and the image plane-side scanning lens 11b, and on the image plane scanning lens 11b and the photosensitive drum 1030. At least one folding mirror may be arranged at least on the optical path between the two.

  As shown in FIG. 11 as an example, the laser chip 100 is provided around 32 light emitting units arranged in a two-dimensional manner and 32 light emitting units, and 32 pieces corresponding to the respective light emitting units. Electrode pads. Each electrode pad is electrically connected to the corresponding light emitting portion by a wiring member.

  As shown in FIG. 12, the 32 light emitting units have the same light emitting unit interval (“c” in FIG. 12) when all the light emitting units are orthogonally projected onto a virtual line extending in the Z-axis direction. Has been placed. In this specification, the “light emitting portion interval” refers to the distance between the centers of two light emitting portions.

  Here, each light emitting unit is a vertical cavity surface emitting laser (VCSEL) having an oscillation wavelength of 780 nm band. That is, the laser chip 100 is a so-called surface emitting laser array chip.

  As shown in FIGS. 13 to 15, each light emitting unit includes a substrate 101, a buffer layer 102, a lower semiconductor DBR 103, a lower spacer layer 104, an active layer 105, an upper spacer layer 106, an upper semiconductor DBR 107, a contact layer 109, and A mode filter 115 and the like are included. 13 is a plan view of one light emitting unit, FIG. 14 is a cross-sectional view taken along the line AA in FIG. 13, and FIG. 15 is a cross-sectional view taken along the line BB in FIG.

  The surface of the substrate 101 is a mirror-polished surface, and as shown in FIG. 16A, the normal direction of the mirror-polished surface (main surface) is crystal orientation with respect to the crystal orientation [1 0 0] direction. [1 1 1] An n-GaAs single crystal substrate inclined 15 degrees (α = 15 degrees) in the A direction. That is, the substrate 101 is a so-called inclined substrate. Here, as shown in FIG. 16B, the crystal orientation [0 −1 1] direction is the + X direction, and the crystal orientation [0 1 −1] direction is the −X direction.

  Returning to FIG. 14, the buffer layer 102 is a layer formed on the + Z side surface of the substrate 101 and made of n-GaAs.

The lower semiconductor DBR 103 is stacked on the + Z side of the buffer layer 102 and 40.5 pairs of a low refractive index layer made of n-AlAs and a high refractive index layer made of n-Al _0.3 Ga _0.7 As. Have. Between each refractive index layer, in order to reduce an electrical resistance, a composition gradient layer having a thickness of 20 nm in which the composition is gradually changed from one composition to the other composition is provided. Each refractive index layer includes 1/2 of the adjacent composition gradient layer, and is set to have an optical thickness of λ / 4 when the oscillation wavelength is λ. When the optical thickness is λ / 4, the actual thickness D of the layer is D = λ / 4n (where n is the refractive index of the medium of the layer).

The lower spacer layer 104 is stacked on the + Z side of the lower semiconductor DBR 103 and is a layer made of non-doped (Al _0.1 Ga _0.9 ) _0.5 In _0.5 P.

  The active layer 105 is laminated on the + Z side of the lower spacer layer 104 and is an active layer having a GaInAsP / GaInP triplet well structure. Each quantum well layer is made of GaInAsP that has a composition that induces 0.7% compressive strain, and each barrier layer is made of GaInP that has a composition that induces 0.6% tensile strain.

The upper spacer layer 106 is laminated on the active layer 105 on the + Z side, and is a layer made of non-doped (Al _0.1 Ga _0.9 ) _0.5 In _0.5 P.

  A portion composed of the lower spacer layer 104, the active layer 105, and the upper spacer layer 106 is also called a resonator structure, and the thickness thereof is set to be an optical thickness of one wavelength. The active layer 105 is provided at the center of the resonator structure at a position corresponding to the antinode in the standing wave distribution of the electric field so that a high stimulated emission probability can be obtained.

The upper semiconductor DBR 107 is laminated on the + Z side of the upper spacer layer 106, and has a low refractive index layer made of p-Al _0.9 Ga _0.1 As and a high refractive index made of p-Al _0.3 Ga _0.7 As. It has 23 pairs of layers. Between each refractive index layer, in order to reduce electrical resistance, a composition gradient layer is provided in which the composition is gradually changed from one composition to the other composition. Each refractive index layer is set to have an optical thickness of λ / 4 including 1/2 of the adjacent composition gradient layer.

  In one of the low refractive index layers in the upper semiconductor DBR 107, a selective oxidation layer made of p-AlAs is inserted with a thickness of 30 nm. The insertion position of the selectively oxidized layer 108 is a position corresponding to the third node from the active layer 105 in the standing wave distribution of the electric field.

  The contact layer 109 is stacked on the + Z side of the upper semiconductor DBR 107 and is a layer made of p-GaAs.

  Note that a structure in which a plurality of semiconductor layers are stacked on the substrate 101 is also referred to as a “stacked body” for convenience in the following.

  The mode filter 115 is provided on the + Z side of the contact layer 109 and in a portion deviated from the central portion in the emission region, and a transparent dielectric film that makes the reflectance of the portion lower than the reflectance of the central portion. Consists of.

  Next, a method for manufacturing the laser chip 100 will be briefly described. Here, it is assumed that the desired polarization direction (referred to as the desired polarization direction P) is the X-axis direction.

(1) The laminate is formed by crystal growth by metal organic chemical vapor deposition (MOCVD) or molecular beam epitaxy (MBE) (see FIG. 17A).

Here, in the case of the MOCVD method, trimethylaluminum (TMA), trimethylgallium (TMG), and trimethylindium (TMI) are used as the group III material, and phosphine (PH ₃ ) is used as the group V material. Arsine (AsH ₃ ) is used. Further, carbon tetrabromide (CBr ₄ ) and dimethyl zinc (DMZn) are used as the raw material for the p-type dopant, and hydrogen selenide (H ₂ Se) is used as the raw material for the n-type dopant.

(2) A square resist pattern having a side of 25 μm is formed on the surface of the laminate.

(3) A square columnar mesa structure (hereinafter abbreviated as “mesa” for convenience) is formed by ECR etching using Cl ₂ gas using the resist pattern as a photomask. Here, the bottom surface of the etching is located in the lower spacer layer 104.

(4) The photomask is removed (see FIG. 17B).

(5) The laminated body is heat-treated in water vapor. As a result, Al (aluminum) in the selectively oxidized layer 108 is selectively oxidized from the outer peripheral portion of the mesa, and an unoxidized region 108b surrounded by the Al oxide layer 108a remains in the central portion of the mesa. (See FIG. 18A). In other words, a so-called oxidized constriction structure is formed that restricts the drive current path of the light emitting part only to the central part of the mesa. The non-oxidized region 108b is a current passage region (current injection region). In this way, for example, a substantially square current passing region having a side of about 4 μm to 6 μm is formed.

(6) A protective layer 111 made of SiN is formed by vapor phase chemical deposition (CVD) (see FIG. 18B). Here, the optical thickness of the protective layer 111 is set to λ / 4. Specifically, since the refractive index n of SiN is 1.86 and the oscillation wavelength λ is 780 nm, the actual film thickness (= λ / 4n) is set to about 105 nm.

(7) An etching mask (referred to as a mask M) for opening a window for the p-side electrode contact is formed on the upper surface of the mesa serving as a laser light emission surface. Here, as an example, as shown in FIG. 19, in a desired polarization direction P (here, the X-axis direction) across the periphery of the mesa, the side surface of the mesa, the outer peripheral portion of the mesa upper surface, and the center of the mesa upper surface. A mask M is created so that two small regions (first small region and second small region) facing each other in the parallel direction are not etched. FIG. 20 is an enlarged view of the mesa upper surface portion in FIG. Specifically, the symbol L1 in FIG. 20 is 5 μm, L2 is 2 μm, and L3 is 8 μm.

(8) The protective layer 111 is etched with BHF to open a window for the p-side electrode contact.

(9) The mask M is removed (see FIGS. 21A and 21B).

(10) A square resist pattern having a side of 14 μm is formed in a region to be a light emitting portion on the upper surface of the mesa, and a p-side electrode material is deposited. As the electrode material on the p side, a multilayer film made of Cr / AuZn / Au or a multilayer film made of Ti / Pt / Au is used.

(11) The electrode material deposited in the region to be the light emitting portion is lifted off to form the p-side electrode 113 (see FIG. 22A). A region surrounded by the p-side electrode 113 is an emission region. Note that a plan view in which the upper surface of the mesa in FIG. 22A is enlarged is shown in FIG. The shape of the injection region is a square having a side length of L4 (here, 10 μm).

(12) Using a vapor phase chemical deposition method (CVD method), as shown in FIG. 23A as an example, a protective layer 117 made of SiN is formed so as to have an optical thickness of 2λ / 4. . Specifically, since the refractive index n of SiN is 1.86 and the oscillation wavelength λ is 780 nm, the actual film thickness (= 2λ / 4n) is set to about 210 nm. Note that FIG. 23B shows an enlarged plan view of the mesa upper surface in FIG.

  Then, the SiN layer having an optical thickness of 3λ / 4 remaining in the first small region becomes the mode filter 115A, and the SiN layer having an optical thickness of 3λ / 4 remaining in the second small region. Becomes the mode filter 115B. Here, the mode filter 115 is composed of the mode filter 115A and the mode filter 115B.

  The reflectance of the portion where the mode filter 115A and the mode filter 115B are present is lower than the reflectance of the central portion of the emission region (see FIGS. 24A and 24B). That is, a low reflectance region and a high reflectance region having a relatively high reflectance exist in the emission region.

  At this time, the central portion of the emission region is covered with a SiN layer (dielectric film) having an optical thickness of 2λ / 4. Further, the area except the two small areas (the first small area and the second small area) at the periphery of the emission area is also covered with a SiN layer (dielectric film) having an optical thickness of 2λ / 4. It will be.

(13) After polishing the back side of the substrate 101 to a predetermined thickness (for example, about 100 μm), an n-side electrode 114 is formed (see FIG. 25). Here, the n-side electrode 114 is a multilayer film made of AuGe / Ni / Au.

(14) Ohmic conduction is established between the p-side electrode 113 and the n-side electrode 114 by annealing. Thereby, the mesa becomes a light emitting part.

(15) Cut for each chip. Note that FIG. 26 is a sectional view taken along the line AA in FIG.

  Then, the laser chip 100 is obtained through various post-processes.

  By the way, the laser module 500 is evaluated using an optical system simulating the configuration and structure of FIG. The evaluation item is a temporal change (output waveform) of the amount of emitted light, and is detected using a photodiode (PD). An example of a normal output waveform is shown in FIG. If there is an influence of return light, the light amount becomes unstable, and the fluctuation (light amount fluctuation) is observed.

  A light amount fluctuation (abnormal waveform) that often appears is schematically shown in FIG. As shown in FIG. 28, the abnormal waveform often appears in the first half of the output waveform, but is not limited thereto, and may appear in the second half. In addition, regarding the frequency, abnormal fluctuations appear even in the case of 1 kHz or in a larger output waveform, for example, several hundred kHz.

  The output waveform is a characteristic necessary for stably drawing one line necessary for the image forming apparatus, and depending on the image forming apparatus, fluctuation of the light amount at a level of several percent becomes a problem.

  Here, when a square wave current pulse having an ambient temperature of 25 ° and a target output of 1.4 mW and a pulse period of 1 ms and a pulse width of 500 μs is supplied to each light emitting section, the light output is 1 μs (Ta) after the supply. Using Dr, the optical output Pb at 480 μs (Tb) after supply, Dr obtained by the following equation (1) is defined as the droop rate (unit:%). This droop rate can be considered as a quantification of the light quantity fluctuation.

Dr = (Pa−Pb) / Pa × 100 (1)

  In a surface emitting laser array having a plurality of light emitting portions, if the droop rate is different for each light emitting portion, the image quality is adversely affected. Therefore, it is necessary to make the droop rate substantially uniform for all the light emitting portions.

  FIG. 29 shows a surface emitting laser array having 21 light emitting portions (ch1 to ch21) and an inexpensive non-reflective glass plate (reflectance: about 1%) as a cover glass, and the glass plate is surface emitting. The droop rate in an optical device (referred to as optical device A) that is not inclined with respect to the emission surface of the laser array is shown. Note that each light emitting unit is not provided with a mode filter. The droop rate was 4% at large and -1.5% at small. This indicates that the output waveform is an abnormal waveform, and the abnormal shape is not uniform depending on the light emitting unit. Such a variation is observed even with a reflectance of only 1% of non-reflective glass. Thus, if an optical device having a large variation in the droop rate between the light emitting portions is used, a high quality image cannot be formed.

  FIG. 30 shows a surface emitting laser array having 21 light emitting portions (ch1 to ch21) and an expensive non-reflective glass plate (reflectance: 0.1%) as a cover glass. The droop rate in an optical device (referred to as optical device B) that is not inclined with respect to the emission surface of the light emitting laser array is shown. Note that each light emitting unit is not provided with a mode filter. The droop rate is 1.5% for a large one and 0.2% for a small one, indicating that the variation is drastically reduced.

  As described above, by using an expensive non-reflective glass having a very low reflectance, resistance to return light is increased, and variation in droop rate is reduced. In addition, it is possible to suppress abnormal waveforms and light amount fluctuations. However, the use of expensive non-reflective glass has the disadvantage that it causes a significant cost increase of the optical device.

  Therefore, the inventors used an inexpensive non-reflective glass plate and tilted the glass plate to examine variations in the droop rate.

  FIG. 31 shows a surface emitting laser array having 21 light emitting portions (ch1 to ch21) and an inexpensive non-reflective glass plate (reflectance: 0.1%) as a cover glass. The droop rate in an optical device (referred to as optical device C) tilted by 8 ° with respect to the emission surface of the light emitting laser array is shown. Note that each light emitting unit is not provided with a mode filter. The droop rate is 3% at the largest and 0.5% at the smallest, and it can be seen that the variation is smaller than that of the optical device A. However, the droop rate variation is larger than that of the optical device B, and an inclination angle of 8 ° is not sufficient.

  FIG. 32 shows a surface emitting laser array having 21 light emitting sections (ch1 to ch21) and an inexpensive non-reflective glass plate (reflectance: 0.1%) as a cover glass. The droop rate in an optical device (referred to as optical device D) tilted by 10 ° with respect to the emission surface of the light emitting laser array is shown. Note that each light emitting unit is not provided with a mode filter.

  FIG. 33 also shows a surface emitting laser array having 21 light emitting portions (ch1 to ch21) and an inexpensive non-reflective glass plate (reflectance: 0.1%) as a cover glass. The droop rate in an optical device (referred to as optical device E) inclined by 15 ° with respect to the emission surface of the surface emitting laser array is shown. Note that each light emitting unit is not provided with a mode filter.

  In the optical device D and the optical device E, the variation in the droop rate was equal to or less than that of the optical device B.

  Thus, it was found that even if an inexpensive non-reflective glass was used, the same effect as using an expensive non-reflective glass can be expected by inclining it.

  Further, the present inventors have found that a larger effect can be expected by providing a mode filter in the emission region. FIG. 34 shows a surface emitting laser array having 21 light emitting portions (ch1 to ch21) each provided with a mode filter similar to the mode filter 115, and an inexpensive non-reflective glass plate (reflectance) as a cover glass. The droop rate in an optical device (referred to as optical device F) in which the glass plate is inclined by 15 ° with respect to the emission surface of the surface emitting laser array is shown. In this optical device F, the variation in the droop rate is further reduced. That is, it can be seen that it is not necessary to use expensive non-reflective glass that causes high costs.

  Therefore, in this embodiment, the stepped structure of the package member 200 is formed so that the inclination angle θ of the cover glass 300 is 17 °.

  Next, a method for manufacturing the optical device 510 will be described.

(A) The laser chip 100 is die-bonded on the bottom surface of the space area of the package member 200.

(B) The plurality of electrode pads of the laser chip 100 and the plurality of metal wirings 203 of the package member 200 are electrically connected individually by bonding wires.

(C) The package member 200 to which the laser chip 100 is fixed and electrically connected to the laser chip 100 is set in the adhesive application holder 400 shown in FIG. At this time, the package member 200 is abutted against the positioning portion of the holder 400. In addition, in FIG. 35, although the six holders 400 are a group, it is not limited to this.

(D) The cover glass 300 is placed on the package member 200. Here, as an example, as shown in FIG. 36, since the bottom surface of the holder 400 is inclined, the cover glass 300 is substantially horizontal. FIG. 36 is a cross-sectional view of the holder 400 before and during application of the adhesive.

(E) An adhesive (ultraviolet curable resin adhesive) for fixing the cover glass 300 placed on the package member 200 is applied.

  Here, the adhesive is applied in the vicinity of three of the four sides of the cover glass 300 as shown in FIG. 37 or 38 as an example.

  For example, when the adhesive is applied as shown in FIG. 37, the adhesive is applied in the order shown in FIG.

  Further, for example, when the adhesive is applied as shown in FIG. 38, in the step of placing the cover glass 300 on the package member 200, the + X side side of the cover glass 300 is the + X side wall of the package member 200 ( It is carried out so as to be abutted against the glass abutting part).

(F) When application of the adhesive is completed, the adhesive is cured. Here, the entire holder 400 is put into an ultraviolet irradiation device and the adhesive is cured. Accordingly, the cover glass 300 is fixed to the package member 200 with an inclination of 17 ° with respect to the emission surface of the laser chip 100.

(G) When the adhesive is cured, the package member 200 is taken out from the holder 400.

  By the way, the application of the adhesive to the vicinity of the inclined side requires the control of the nozzle in the three axial directions. Such an apparatus capable of three-axis control is very expensive, and requires an operation while performing high-level control, so that the operation becomes slow and the tact time becomes long.

  Here, since the bottom surface of the holder 400 on which the package member 200 is placed is inclined so that the cover glass 300 is substantially horizontal, biaxial control is sufficient for controlling the nozzle. As a result, the tact time was shortened by 3 seconds, and the yield in the adhesive application process was improved from 87% to 99%.

  Further, since the adhesive is applied in the vicinity of three of the four sides of the cover glass 300, the space region of the package member 200 is prevented from being sealed.

  As described above, the optical device 510 has a structure in which the space region of the package member 200 is not sealed by the cover glass 300. However, in the portion where the adhesive is not applied, the ceramic of the package member 200 and the cover glass 300 are separated. There is a certain amount of microscopic surface roughness gap between the ceramic and the cover glass 300. Due to such a structure, the optical device 510 allows moisture and the like to pass therethrough but prevents microscopic dust from entering the space region. Of course, in the portion where the adhesive is applied, there is no gap between the ceramic and the cover glass 300 to allow dust to pass through.

  The microscopic surface roughness of ceramic varies depending on the type of ceramic, but if it is 1 μm or less, in principle, dust of 1 μm or more will not pass through the gap. If the dust is 1 μm or less, even if it adheres to the emission region of the laser chip 100, the effect is negligible. Therefore, the surface roughness of the ceramic may be about 1 μm.

  Moreover, it has been confirmed here that even if an inexpensive resin adhesive is used, there is no problem due to condensation. As the adhesive, an inexpensive epoxy or acrylic adhesive can be used.

  As described above, the optical device 510 according to this embodiment includes the laser chip 100, the package member 200 that holds the laser chip 100, the cover glass 300, and the like.

  The surface of the cover glass 300 on which the light emitted from the laser chip 100 is incident is inclined at an inclination angle of 17 ° with respect to the emission surface of the laser chip 100 and is fixed to the package member 200 with an adhesive.

  And the adhesive agent is not apply | coated to a part of part which is supporting the cover glass 300 in the package member 200. FIG. That is, the space area of the package member 200 is not sealed.

  In this case, even if an inexpensive non-reflective glass plate (reflectance = about 1%) is used as the cover glass 300, it is possible to prevent the return light from entering the active layer of the laser chip 100.

  Even if an inexpensive resin-based adhesive is used as the adhesive, it is possible to suppress the occurrence of problems due to condensation.

  Therefore, it is possible to emit stable light with little light amount fluctuation without increasing the cost.

  Further, a part of the wall of the package member 200 has a stepped structure, and one end of the cover glass 300 is supported by the stepped portion. In this case, the inclination angle of the cover glass 300 can be easily set to a desired inclination angle. Thereby, the yield in the glass plate attaching process was improved from 80% to 95%.

  By the way, when the space area of the package member is sealed with a cover glass using a resin adhesive, the resin adhesive has a property of allowing a small amount of moisture to pass through. It will gradually increase. If a sudden temperature change occurs at that time, condensation occurs, resulting in a fatal defective product. If a metal seal such as a CAN package is used, moisture permeation is lost, but the cost is high because the material is more expensive.

  Further, in each light emitting unit, since the emission surface is covered with a dielectric film and the semiconductor is not exposed, oxidation and contamination of the emission region can be suppressed. Although the central portion of the emission region is covered with the dielectric film 117, since the optical thickness is an even multiple of λ / 4, the reflectance is not lowered, and the dielectric film 117 is Optical characteristics equivalent to the case without the same are obtained.

  Further, in each light emitting unit, the side surface of the mesa and the side surface of the stacked body are covered with the dielectric film, and the semiconductor is not exposed, so that the oxidation and contamination of the semiconductor can be suppressed.

  In addition, each light emitting unit has a mode filter 115 that is provided in the emission region and is made of a transparent dielectric film that lowers the reflectance of the peripheral portion to be lower than that of the central portion. Can be obtained. The mode filter 115 is composed of two mode filters 115A and a mode filter 115B arranged with a central portion interposed therebetween, and a region having a relatively high reflectance sandwiched between the mode filters has a shape anisotropy. Therefore, the polarization direction can be made uniform.

  In addition, since the light source unit 14 includes the optical device 510, the optical scanning device 1010 according to the present embodiment can perform stable optical scanning without incurring an increase in cost.

  In addition, since the laser chip 100 has a plurality of light emitting portions, a plurality of optical scans can be performed at the same time, and the speed of image formation can be increased.

  Since the laser printer 1000 according to this embodiment includes the optical scanning device 1010, it is possible to form a high-quality image.

  Further, in the laser chip 100, since the intervals between the light emitting portions when the respective light emitting portions are orthogonally projected onto a virtual line extending in the sub-scanning corresponding direction are equal intervals c, the lighting timing is adjusted to adjust the lighting timing on the photosensitive drum 1030. It can be considered that the configuration is the same as the case where the light emitting units are arranged at equal intervals in the sub-scanning direction.

  For example, if the interval c is 2.65 μm and the magnification of the optical system of the optical scanning device 1010 is doubled, high-density writing of 4800 dpi (dots / inch) can be performed. Of course, the number of light emitting units in the main scanning direction is increased, the array d is further reduced by reducing the pitch d (see FIG. 12) in the sub scanning direction, and the interval c is further reduced, or the magnification of the optical system is decreased. For example, higher density can be achieved and higher quality printing becomes possible. Note that the writing interval in the main scanning direction can be easily controlled by the lighting timing of the light emitting unit.

  In this case, the laser printer 1000 can perform printing without decreasing the printing speed even if the writing dot density increases. Further, when the writing dot density is the same, the printing speed can be further increased.

  In this case, since the polarization directions of the light beams from the respective light emitting units are stably aligned, the laser printer 1000 can stably form a high-quality image.

  In the above-described embodiment, the case where the surface of the cover glass 300 on which the light emitted from the laser chip 100 is incident is inclined with respect to the emission surface of the laser chip 100 at an inclination angle of 17 °. It is not limited, and the inclination angle may be 10 ° or more. At this time, the inclination angle is more preferably 15 ° or more.

  Moreover, although the said embodiment demonstrated the case where the shape of each small area | region was a rectangle, it is not limited to this (for example, refer FIG. 40).

  In the above embodiment, when the desired polarization direction P is the Y-axis direction, the direction in which the first small region and the second small region face each other may be the Y-axis direction (see FIG. 41).

  Further, when it is not necessary to consider the polarization direction, one region having an isotropic shape as shown in FIGS. 42 and 43 may be used as a low reflectance region as an example.

Further, in the above embodiment, the protective layer 111 and the protective layer 117 has been described for the case of SiN, not limited to this, for _example, SiN _x, SiO x, may be any of TiO _x and SiON. The same effect can be obtained by designing the film thickness according to the refractive index of each material.

  Moreover, although the said embodiment demonstrated the case where each mode filter was the same material as the protective layer 111 and the protective layer 117, it is not limited to this.

  Moreover, in the said embodiment, as FIG. 44-FIG. 46 shows as an example, the said protective layer 117 does not need to be laminated | stacked. At this time, each mode filter is composed of a dielectric film 111 made of SiN having an optical thickness of λ / 4.

  In the above embodiment, the case where the normal direction of the main surface of the substrate is inclined 15 degrees toward the crystal orientation [1 1 1] A direction with respect to the crystal orientation [1 0 0] direction is described. However, the present invention is not limited to this. The normal direction of the main surface of the substrate may be inclined toward one direction of crystal orientation <1 1 1> with respect to one direction of crystal orientation <1 0 0>.

  Moreover, although the said embodiment demonstrated the case where a board | substrate was an inclination board | substrate, it is not limited to this, A board | substrate may be a non-inclination board | substrate.

  In the above embodiment, instead of the laser chip 100, a laser chip in which light emitting units similar to the laser chip 100 are arranged one-dimensionally may be used.

  Moreover, although the said embodiment demonstrated the case where the oscillation wavelength of a light emission part was a 780 nm band, it is not limited to this. The oscillation wavelength of the light emitting unit may be changed according to the characteristics of the photoreceptor.

  Further, the optical device 510 can be used for applications other than the image forming apparatus. In that case, the oscillation wavelength of the laser chip 100 may be a wavelength band such as a 650 nm band, an 850 nm band, a 980 nm band, a 1.3 μm band, and a 1.5 μm band, depending on the application. In this case, a mixed crystal semiconductor material corresponding to the oscillation wavelength can be used as the semiconductor material constituting the active layer. For example, an AlGaInP mixed crystal semiconductor material can be used in the 650 nm band, an InGaAs mixed crystal semiconductor material can be used in the 980 nm band, and a GaInNAs (Sb) mixed crystal semiconductor material can be used in the 1.3 μm band and the 1.5 μm band.

  Further, by selecting the material and configuration of each reflecting mirror according to the oscillation wavelength, a light emitting unit corresponding to an arbitrary oscillation wavelength can be formed. For example, other than AlGaAs mixed crystal such as AlGaInP mixed crystal can be used. The low refractive index layer and the high refractive index layer are preferably a combination that is transparent with respect to the oscillation wavelength and can take a difference in refractive index as much as possible.

  In this case, a surface emitting laser element having one light emitting portion may be used instead of the laser chip 100.

  In the above embodiment, the case where the optical scanning device 1010 is used in a printer has been described. However, the optical scanning device 1010 may be used in an image forming apparatus other than a printer, for example, a copier, a facsimile, or a multifunction machine in which these are integrated. it can.

  In the above embodiment, the laser printer 1000 is described as the image forming apparatus. However, the present invention is not limited to this.

  Further, an image forming apparatus that directly irradiates a medium (for example, paper) with a laser beam by a laser beam may be used.

  For example, the medium may be a printing plate known as CTP (Computer to Plate). That is, the optical scanning device 1010 is also suitable for an image forming apparatus that forms a printing plate by directly forming an image on a printing plate material by laser ablation.

  For example, the medium may be so-called rewritable paper. For example, a material described below is applied as a recording layer on a support such as paper or a resin film. Then, reversibility is imparted to color development by thermal energy control by laser light, and display / erasure is performed reversibly.

  There are a transparent cloudy type rewritable marking method and a color developing / erasing type rewritable marking method using a leuco dye, both of which can be applied.

  The transparent cloudy type is a polymer thin film in which fine particles of fatty acid are dispersed. When heated to 110 ° C. or higher, the resin expands due to melting of the fatty acid. Thereafter, when cooled, the fatty acid becomes supercooled and remains in a liquid state, and the expanded resin solidifies. Thereafter, the fatty acid solidifies and shrinks to become polycrystalline fine particles, and voids are formed between the resin and the fine particles. Light is scattered by this gap and appears white. Next, when heated to an erasing temperature range of 80 ° C. to 110 ° C., the fatty acid partially melts, and the resin thermally expands to fill the voids. If it cools in this state, it will be in a transparent state and an image will be erased.

  The rewritable marking method using a leuco dye utilizes a reversible color development and decoloration reaction between a colorless leuco dye and a developer / decolorant having a long-chain alkyl group. When heated by laser light, the leuco dye and the developer / decolorant react to develop color, and when rapidly cooled, the colored state is maintained. Then, when it is slowly cooled after heating, phase separation occurs due to the self-aggregating action of the long-chain alkyl group of the developer / decolorant, and the leuco dye and developer / decolorizer are physically separated and decolored.

  In addition, when the medium is exposed to ultraviolet light, the photochromic compound develops color in C (cyan) and disappears with visible R (red) light, and when exposed to ultraviolet light, the medium develops in M (magenta). A photochromic compound that is decolored by G (green) light, a photochromic compound that develops color when exposed to ultraviolet light (Y) and is decolored by visible B (blue) light. So-called color rewritable paper provided on the body may be used.

  This is a method of expressing full color by controlling the color density of the three types of materials that develop color in Y, M, and C by the time and intensity of applying R, G, and B light once it is made black by applying ultraviolet light. However, if the strong light of R, G, and B is continuously applied, all three types can be decolored to become pure white.

  Such an apparatus that imparts reversibility to color development by light energy control can also be realized as an image forming apparatus including an optical scanning device similar to that of the above embodiment.

  Further, an image forming apparatus using a silver salt film as the image carrier may be used. In this case, a latent image is formed on the silver salt film by optical scanning, and this latent image can be visualized by a process equivalent to a developing process in a normal silver salt photographic process. Then, it can be transferred to photographic paper by a process equivalent to a printing process in a normal silver salt photographic process. Such an image forming apparatus can be implemented as an optical plate making apparatus or an optical drawing apparatus that draws a CT scan image or the like.

  As an example, as shown in FIG. 47, a color printer 2000 including a plurality of photosensitive drums may be used.

  The color printer 2000 is a tandem multicolor printer that forms a full-color image by superimposing four colors (black, cyan, magenta, and yellow). The black “photosensitive drum K1, charging device K2, "Developing device K4, cleaning unit K5, and transfer device K6", cyan "photosensitive drum C1, charging device C2, developing device C4, cleaning unit C5, and transfer device C6", and magenta "photosensitive drum" M1, charging device M2, developing device M4, cleaning unit M5, and transfer device M6 ”,“ photosensitive drum Y1, charging device Y2, developing device Y4, cleaning unit Y5, and transfer device Y6 ”for yellow, and light A scanning device 2010, a transfer belt 2080, a fixing unit 2030, and the like are provided.

  Each photoconductor drum rotates in the direction of the arrow in FIG. 47, and a charging device, a developing device, a transfer device, and a cleaning unit are arranged around each photoconductor drum along the rotation direction. Each charging device uniformly charges the surface of the corresponding photosensitive drum. The surface of each photoconductive drum charged by the charging device is irradiated with light by the optical scanning device 2010, and a latent image is formed on each photoconductive drum. Then, a toner image is formed on the surface of each photosensitive drum by a corresponding developing device. Further, the toner image of each color is transferred onto the recording paper on the transfer belt 2080 by the corresponding transfer device, and finally the image is fixed on the recording paper by the fixing unit 2030.

  The optical scanning device 2010 has a light source unit including an optical device similar to the optical device 510 for each color. Therefore, the same effect as that of the optical scanning device 1010 can be obtained. In addition, since the color printer 2000 includes the optical scanning device 2010, the same effect as the laser printer 1000 can be obtained.

  By the way, in the color printer 2000, color misregistration may occur due to manufacturing error or position error of each component. Even in such a case, color misregistration can be reduced by selecting a light emitting unit to be lit.

  As described above, the optical device of the present invention is suitable for emitting stable light with little fluctuation in light amount without increasing the cost. Further, the optical scanning device of the present invention is suitable for performing stable optical scanning without causing an increase in cost. The image forming apparatus of the present invention is suitable for forming a high quality image.

  DESCRIPTION OF SYMBOLS 11a ... Deflector side scanning lens (a part of scanning optical system), 11b ... Image surface side scanning lens (a part of scanning optical system), 13 ... Polygon mirror (deflector), 14 ... Light source unit, 100 ... Laser chip (Surface emitting laser array), 101 ... substrate, 103 ... lower semiconductor DBR (part of semiconductor multilayer reflector), 104 ... lower spacer layer (part of resonator structure), 105 ... active layer, 106 ... upper part Spacer layer (part of resonator structure), 107 ... upper semiconductor DBR (part of semiconductor multilayer reflector), 108 ... selective oxidation layer, 108b ... current passage region, 113 ... p-side electrode (electrode), 115: Mode filter (dielectric film), 115A: Mode filter (part of the dielectric film), 115B: Mode filter (part of the dielectric film), 200: Package member, 300: Cover glass (transparent) Material), 510 ... Optical device, 1000 ... Laser printer (image forming apparatus), 1010 ... Optical scanning apparatus, 1030 ... Photosensitive drum (image carrier), 2000 ... Color printer (image forming apparatus), 2010 ... Optical scanning apparatus , K1, C1, M1, Y1... Photosensitive drum (image carrier).

JP 2005-252032 A Japanese Patent Laying-Open No. 2005-086027 JP 2007-103576 A

Claims (14)

In an optical device comprising a surface-emitting laser element and a package member that holds the surface-emitting laser element on the bottom surface of a space region surrounded by a wall,
Further comprising a transparent member held on the package member and disposed on an optical path of light emitted from the surface emitting laser element;
In the transparent member, a surface on which light emitted from the surface emitting laser element is incident is inclined with respect to an emission surface of the surface emitting laser element, and is fixed to the package member with an adhesive,
The optical device, wherein the adhesive is not applied to a part of the portion of the package member that supports the transparent member.   2. The light according to claim 1, wherein a surface of the transparent member on which light emitted from the surface emitting laser element is incident is inclined by 10 ° or more with respect to an emission surface of the surface emitting laser element. device. The transparent member is a polygonal plate-shaped member,
The optical device according to claim 1, wherein an adhesive is not applied to at least a part of one side of the polygon.   The at least part of the wall in the space region has a stepped structure portion, and the transparent member is supported by a step portion of the stepped structure portion. The optical device according to any one of the above.   The optical device according to claim 4, wherein the step portion supports one of the vicinity of the end portion and a portion other than the vicinity of the end portion in one longitudinal section of the transparent member.   6. The optical device according to claim 1, wherein the surface emitting laser element has an emission surface covered with a dielectric film, and a semiconductor is not exposed. The surface-emitting laser element has a plurality of semiconductors stacked on a substrate,
The optical device according to any one of claims 1 to 6, wherein the plurality of semiconductors have a side surface covered with a dielectric film and are not exposed.   8. The surface emitting laser element according to claim 1, further comprising a transparent dielectric film that is provided in an emission region and has a peripheral portion having a different reflectance from a central portion. The optical device according to.   The optical device according to claim 1, wherein the surface emitting laser element is a surface emitting laser array having a plurality of light emitting units. An optical scanning device that scans a surface to be scanned with light,
A light source comprising the optical device according to claim 1;
A deflector for deflecting light from the light source;
A scanning optical system for condensing the light deflected by the deflector onto the surface to be scanned. At least one image carrier;
An image forming apparatus comprising: at least one optical scanning device according to claim 10 that scans light including image information on the at least one image carrier.   The image forming apparatus according to claim 11, wherein the image information is multicolor image information. The method for manufacturing an optical device according to any one of claims 1 to 8, wherein the surface emitting laser element and the transparent member are held by a package member,
Placing the transparent member on the package member to which the surface emitting laser element is fixed and electrically connected to the surface emitting laser element;
Inclining the package member such that a surface of the transparent member on which light emitted from the surface emitting laser element is incident is horizontal;
Applying an adhesive for fixing the transparent member to the package member.   The manufacturing method according to claim 13, wherein in the step of tilting the package member, the package member is placed on a holder whose bottom surface is tilted.

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