JP4270441B2 - Light source module - Google Patents

Description

  The present invention relates to a light source module that emits a light beam, and this light source module is used for drawing with a light beam on, for example, a semiconductor or glass substrate or a printing plate.

  2. Description of the Related Art Conventionally, as a light source module used for drawing on a semiconductor or glass substrate, a printing plate, or the like, a combination of a semiconductor laser of a CAN package and a collimator lens has been known. A light source module having a structure in which a collimator lens is provided instead of the glass window of the mouth is used by being attached to a mounting member. In such a light source module, the light source module is positioned by inserting a positioning pin erected on the mounting member into the positioning hole of the holder of the CAN package, and the reference surface of the holder is used as the mounting member. The direction of the light beam emitted by being brought into contact with is determined.

Patent Document 1 discloses a structure in which a semiconductor laser of a CAN package is provided on one side of a hole formed in a stay for attaching a light source that constitutes a part of a light source unit, and a collimator lens is disposed inside the hole. Has been. Patent Document 1 proposes a light source unit in which a plurality of light source modules having such a structure are arranged.
JP-A-6-47954

  By the way, in a light source unit having a plurality of light source modules as disclosed in Patent Document 1, it is necessary to accurately determine the emission positions and emission angles of a plurality of light beams. Further, when a semiconductor laser of a CAN package is used as a light source, power is supplied to the semiconductor laser by directly soldering a wiring to an electric terminal protruding from the CAN package. There is also a possibility that the emission position and the emission angle of the light beam are shifted.

  Furthermore, due to the influence of vibration, heat, etc. when the light source unit is used, the light beam emission position and emission angle may deviate from the position and angle at the time of manufacturing the light source unit due to changes over time.

  The present invention has been made in view of the above problems, and an object thereof is to accurately determine an emission position and an emission angle of light from a light source module with respect to a mounting plate.

The invention according to claim 1 is a light source module that is attached to an opening of a predetermined attachment plate, and a light source, a lens portion that receives light from the light source and is inserted into the opening of the attachment plate, A light source and a structure that holds the lens unit, and the lens unit emits light relative to the mounting plate by fitting an outer surface that is parallel to the optical axis and inserted into the opening. Provided as a position reference surface for determining the position, and the structure is a surface approximately perpendicular to the optical axis provided around the lens portion and abuts against the main surface of the mounting plate to contact the mounting plate. An angle reference surface that determines a relative light emission angle, and a pressed portion that is substantially parallel to the optical axis on the side opposite to the lens portion of the light source and is pressed in a direction toward the angle reference surface It equipped with a door, Serial pressed portion is Ru Oh electrical terminals connected to the light source while being pressed by the connected electric probe to a power supply source.

The invention according to claim 2 is the light source module according to claim 1 , wherein the mounting plate is connected to the power supply source, and the position reference plane or the angle reference plane is connected to the light source. Another electrical terminal.

A third aspect of the present invention is the light source module according to the first or second aspect , wherein the light source is a semiconductor laser.

A fourth aspect of the present invention is the light source module according to any one of the first to third aspects, wherein the lens unit includes a collimator lens.

In the present invention, the emission position and emission angle of light from the light source module with respect to the mounting plate can be determined with high accuracy. In addition, it is possible to prevent the light emission position and the light emission angle from the light source module from changing with time. Furthermore, the power supply structure to the light source module can be simplified.

In the invention of claim 2, the structure for supplying power to the light source module can be simplified.

  FIG. 1 is a perspective view showing a configuration of a light source module 1 according to an embodiment of the present invention. FIGS. 2 to 5 are plan views of the light source module 1, respectively, from the (+ X) side in FIG. It is a front view, left side view, and right side view. As shown in FIG. 1, a light source module 1 includes a semiconductor laser bare chip (hereinafter simply referred to as “semiconductor laser”) 11 that is a light source that emits a light beam, and a lens unit 12 on which the light beam from the semiconductor laser 11 is incident. In addition, a structure (hereinafter referred to as “platform”) 13 that holds the semiconductor laser 11 and the lens unit 12 is provided.

  As shown in FIGS. 2 and 3, the semiconductor laser 11 is mounted on the submount 112 and then mounted inside the platform 13 by a method such as soldering.

  The lens unit 12 includes a collimator lens 123 (for example, a SELFOC (registered trademark) lens) having an optical axis 121 indicated by a one-dot chain line in FIGS. 2 and 3, and a cylindrical lens holder having a collimator lens 123 therein. 122, the central axis of the lens portion outer surface 122a parallel to the optical axis 121 of the lens holder 122 coincides with the optical axis 121 with high accuracy. That is, in the lens unit 12, the center of the cross section when cut by a plane perpendicular to the optical axis 121 coincides with the optical axis 121 with high accuracy. The lens unit 12 may be the collimator lens 123 itself (or a lens whose side surface is metallized). In this case, the side surface of the collimator lens 123 becomes the lens unit outer surface 122a.

  The lens unit 12 is aligned (positioned) so that the optical axis 121 and the principal ray of the light beam emitted from the semiconductor laser 11 coincide with each other with high accuracy, and using solder, glass powder, UV adhesive, or the like, or It is fixed to the platform 13 by welding with a YAG laser. At this time, the lens portion 12 (a part thereof) is fixed so as to protrude to the outside of the platform 13 and serves as a protrusion for determining the mounting position of the light source module 1.

  The platform 13 is made of a material having a high thermal conductivity and a low thermal expansion coefficient, for example, copper tungsten (CuW) or the like, and is formed in three directions around the lens unit 12 (the (+ X) side of the lens unit 12 in FIG. 5). A wire 131 is connected to a surface 131 provided in a substantially U shape so as to surround the (−X) side and the (−Y) side) and one electrode of the semiconductor laser 11 (an anode in the present embodiment). The module electrode 14 is connected by a wire bonding method, and the surface 131 is perpendicular to the optical axis 121.

  As shown in FIG. 3, the module electrode 14 is on the side opposite to the lens portion 12 of the semiconductor laser 11 and opposed to the vicinity of the central portion of the surface 131 (that is, near the optical axis 121 extended to (+ Z)). The module electrode 14, the semiconductor laser 11, the central portion of the surface 131, and the lens portion 12 are arranged in a substantially straight line in the direction along the optical axis 121. As shown in FIG. 4, the module electrode 14 is joined while being insulated from the platform 13 via the insulating material 15. Further, the surface of the platform 13 excluding the module electrode 14 and the insulating material 15 is plated with gold, and as shown in FIGS. 2 and 3, the other electrode (cathode in this embodiment) of the semiconductor laser 11 is applied. They are connected via wires 113.

  In the light source module 1, a light beam is emitted from the semiconductor laser 11 by the power supplied from the power supply source via the surface of the platform 13 and the module electrode 14, and this light beam is incident on the lens unit 12 and enters the optical axis 121. The light is emitted from the lens unit 12 as parallel light.

  FIG. 6 is an exploded perspective view showing the structure of the optical unit 2 including a plurality (9 in the present embodiment) of the light source modules 1. In FIG. 6, for convenience of illustration, only three light source modules 1 are drawn.

  The optical unit 2 has a mounting plate 20 (consisting of two plates 22 and 23 described later) in which a plurality of mounting openings 201 into which the light source module 1 is inserted are formed on the light beam emission side of the plurality of light source modules 1. , And a unit base 21 in which a plurality of openings 211 corresponding to the plurality of attachment openings 201 are formed. The mounting plate 20 is positioned at a position corresponding to the positioning opening 221, and a thin film positioning plate 22 in which a plurality of positioning openings 221 into which the plurality of light source modules 1 are respectively inserted are accurately formed at predetermined positions by etching. An angle determining plate 23 having an opening 231 slightly larger than the opening 221 is provided. The mounting opening 201 is obtained by overlapping the positioning opening 221 and the opening 231, and the (+ Z) side surface of the angle determination plate 23 is an arrangement surface 232 that is a plane on which the plurality of light source modules 1 are arranged.

  The optical unit 2 further includes a pressing unit 30 that sandwiches the plurality of light source modules 1 with the arrangement surface 232 and presses the plurality of light source modules 1 toward the arrangement surface 232, and the pressing unit 30 includes the plurality of light source modules. A plurality of electrical probes 24 (only three are shown) that are provided at portions that abut against 1 and supply power to the plurality of light source modules 1 respectively, and a plurality of openings 251 into which the electrical probes 24 are inserted are formed. A heat dissipating sheet 25, a plurality of openings 261 corresponding to the openings 251 and a probe holding plate 26 for holding the electric probes 24 inserted into the openings 261, a wiring board 27 with which the plurality of electric probes 24 abut, A radiator 28 (for example, a water cooling jacket, an air cooling fan, a Peltier element, etc.) is provided. The electric probe 24 has a substantially cylindrical shape and has a spring inside, and is elastically contracted by applying a force so as to be compressed from the longitudinal direction.

  When the optical unit 2 is assembled, first, the positioning plate 22 is attached in contact with the reference surface 212 of the unit base 21 on the surface opposite to the side where the light source module 1 is inserted. 23 is attached to the unit base 21 with the positioning plate 22 sandwiched between it and the reference surface 212. The angle determining plate 23 has a thickness of 0.1 mm to 0.2 mm, and has a function as a reinforcing plate that reinforces the thin positioning plate 22 with the unit base 21 interposed therebetween.

  Subsequently, the plurality of lens portions 12 of the plurality of light source modules 1 are inserted into the mounting openings 201 of the mounting plate 20. The positioning opening 221 of the positioning plate 22 is formed so that the center coincides with the optical axis 121 of the lens unit 12 with high accuracy and the inner diameter fits with the lens unit outer surface 122a with high accuracy, and is inserted into the positioning opening 221. The lens portion outer surface 122a is a reference surface that determines the position of the optical axis 121 relative to the mounting plate 20, that is, the light beam emission position, by fitting (hereinafter, the lens portion outer surface 122a is referred to as a "position reference surface 122a"). It is said.)

  Further, the arrangement surface 232 of the angle determining plate 23 constituting the mounting plate 20 is formed as a flat surface with a high degree of flatness, and is a surface perpendicular to the optical axis 121 provided around the lens portions 12 of the plurality of light source modules 1. 131 (refer to FIG. 5) refers to the emission angle (emission direction) of the light beam relative to the mounting plate 20 (the tilt angle and the tilt direction with respect to the normal of the mounting plate 20) by abutting against the arrangement surface 232. ) Is determined (hereinafter, the surface 131 is referred to as an “angle reference surface 131”).

  As described above, by attaching the plurality of light source modules 1 to the mounting plate 20 (that is, the positioning plate 22 and the angle determining plate 23), the relative positions of the plurality of light source modules 1 with respect to the respective optical units 2 are The direction of the light beam emitted from the light source module 1 is determined by the fitting of the lens unit 12 (position reference surface 122a) and the positioning opening 221, and the light source module 1 (angle reference surface 131) is arranged on the arrangement surface 232. It is determined by contacting the

  Next, the plurality of openings 251 and 261 of the heat dissipation sheet 25 and the probe holding plate 26 are aligned with the module electrodes 14 of the light source module 1, respectively, and the unit is arranged with the plurality of light source modules 1 sandwiched between the arrangement surfaces 232. It is attached to the base 21 (illustration of screws for attachment etc. is omitted). The electric probe 24 is inserted into each of the plurality of openings 251 and 261 substantially parallel to the optical axis 121 of the lens unit 12 of the light source module 1, and the tip of the electric probe 24 contacts the module electrode 14 of the light source module 1.

  Subsequently, the wiring board 27 connected to the power supply source 29 via the connector 271 and the cable 291 comes into contact with the end of the plurality of electric probes 24 on the side opposite to the tip of the module electrode 14 and comes into contact with the probe. It is attached to the holding plate 26. Wiring corresponding to the plurality of electric probes 24 is formed in advance on the surface of the wiring board 27 in contact with the electric probes 24. The plurality of electric probes 24 are pressed and elastically contracted between the wiring board 27 and the plurality of light source modules 1, and press the light source module 1 toward the arrangement surface 232 of the angle determination plate 23 with a force of several tens of grams. . More specifically, the module electrode 14, which is also a pressed part that is pressed against and directly pressed against one end of the elastically contracted electric probe 24, is connected to the power supply source 29 via the wiring board 27. When the probe 24 is pressed in a direction substantially parallel to the optical axis 121 of the lens unit 12 and toward the angle reference surface 131, the angle reference surface 131 is pressed against and closely contacts the arrangement surface 232.

  At this time, one electrode (anode) of the semiconductor laser 11 of the light source module 1 is electrically connected to the power supply source 29 via the module electrode 14, the electric probe 24 and the wiring board 27. Further, the other electrode (cathode) of the semiconductor laser 11 is electrically connected to the arrangement surface 232 of the mounting plate 20 via the angle reference surface 131 of the gold-plated platform 13, and the arrangement surface 232 that is a conductor is The power supply source 29 is connected via a common cable 292. That is, the module electrode 14 and the angle reference plane 131 of the light source module 1 serve as electrical terminals that are connected to the semiconductor laser 11 of the light source module 1 and supply power to the semiconductor laser 11.

  In addition, when the position reference surface (lens part outer surface) 122a of the light source module 1 and the positioning plate 22 fitted thereto are conductors (for example, a thin film metal plate), instead of the angle reference surface 131. The position reference surface 122 a may be one electrical terminal of the light source module 1. In this case, the electrode (cathode) of the semiconductor laser 11 may be connected to the position reference surface 122a via the gold-plated surface of the light source module 1, or may be directly connected to the position reference surface 122a by a wire bonding method or the like. Good. Further, the positioning plate 22 and the power supply source 29 may be connected via the angle determining plate 23 or directly.

  In the optical unit 2, the radiator 28 is further attached in contact with the back surface of the wiring board 27 (the surface opposite to the main surface where the wiring that contacts the electric probe 24 is formed in advance). FIG. 7 is a cross-sectional view showing the structure of the assembled optical unit 2. For convenience of illustration, only one light source module 1 is shown in FIG. In addition, screws that connect the unit base 21 and the mounting plate 20 to the probe holding unit 26 and the wiring board 27 are indicated by a one-dot chain line.

  As described above, in the optical unit 2 using the plurality of light source modules 1, the plurality of light source modules 1 arranged on the mounting plate 20 are pressed against the mounting plate 20 by the electric probe 24, and then the electric probe 24 and the mounting plate are used. Electric power is supplied via 20, and a plurality of light beams are emitted at an emission position and an emission angle determined with high accuracy. At this time, a large amount of thermal energy is emitted from the plurality of semiconductor lasers 11. The released thermal energy is efficiently transmitted to the probe holding plate 26 through the platform 13 and the heat dissipation sheet 25 formed of copper tungsten having a high thermal conductivity. As described above, since copper tungsten has a low coefficient of thermal expansion, deformation of the light source module 1 due to thermal energy emitted from the semiconductor laser 11 is suppressed, and fluctuations in the emission position and emission angle of the light beam are suppressed. .

  The thermal energy transmitted to the probe holding plate 26 is transmitted to the radiator 28 via the wiring board 27 and is efficiently radiated by the radiator 28. As a material for forming the probe holding plate 26 and the wiring board 27, heat insulation is high, and insulation for supplying power from the power supply source 29 (see FIG. 6) to the light source module 1 through the electric probe 24 is used. Ceramics such as aluminum nitride (AlN), beryllia (beryllium oxide (BeO)), and the like that also have good properties are preferable. As described above, in the optical unit 2, even when a plurality of semiconductor lasers 11, which are high-output light sources that generate significant heat, are used, the thermal energy generated from the light source is transferred to the rear of the light source module 1 (the direction of emitting the light beam) A sufficient amount of heat radiation can be secured by efficiently transmitting the heat to the radiator 28 arranged on the opposite side.

  FIG. 8 is a diagram showing a structure of a raster scanning type image recording apparatus 3 using an optical unit 2 including a plurality of light source modules 1. Sixteen light source modules 1 are used in the optical unit 2 of the image recording apparatus 3. Other configurations are the same as those in FIG.

  The image recording apparatus 3 includes an optical unit 2 having a plurality of light source modules 1, an aperture plate 31, a field lens 32, a zoom optical system 33, and a base portion 34 that holds these configurations, and a photosensitive material is applied. A drum 35 is provided to hold the formed plate material on the outer surface. In the image recording apparatus 3, the beam shapes of a plurality of light beams emitted from the optical unit 2 are shaped by the aperture plate 31, and the plate material on the drum 35 is formed by the field lens 32 and the zoom optical system 33 that are both-side telecentric optical systems. Guided to the drawing area 91. The main scanning of the plurality of light beams with respect to the printing plate is performed by rotation around the central axis of the drum 35, and the sub-scanning is performed by moving the base portion 34 in a direction parallel to the central axis of the drum 35. In the image recording apparatus 3, since the plurality of light source modules 1 are accurately arranged in the optical unit 2 so that the plurality of emitted light beams are emitted at a predetermined emission position and emission angle, high-precision drawing is performed. Is realized.

  As described above, in the light source module 1, the position reference surface 122 a is inserted into the positioning opening 221 of the mounting plate 20 and attached to the mounting plate 20 by fitting, so that the light beam emission position relative to the mounting plate 20 is obtained. Can be determined with high accuracy. Further, when the angle reference surface 131 is in contact with the arrangement surface 232 of the mounting plate 20, it is possible to accurately determine the emission angle of the light beam relative to the mounting plate 20. Furthermore, since the light beam emission point (end surface on the emission side of the lens unit 12), the position reference surface 122a, and the angle reference surface 131 are arranged close to each other, the light beam emission position and angle are determined with higher accuracy. The light source module 1 itself can be easily manufactured.

  Further, in the light source module 1, the module electrode 14 that is the pressed portion is pressed and the angle reference surface 131 is pressed against the arrangement surface 232 of the mounting plate 20, whereby the emission position and emission of the light beam from the light source module 1. It is possible to prevent the change of the angle with time.

  Furthermore, in the light source module 1, the module electrode 14 and the angle reference surface 131 (or the position reference surface 122 a) serve as electrical terminals that supply power to the semiconductor laser 11, so that the power supply structure can be simplified. It is possible to determine the emission position and the emission angle of the light beam without being constrained by the electric wiring. Further, the connection of the power supply structure (for example, soldering of the wiring to the electric terminal) performed after the light source module 1 is attached is simplified (or omitted), and the light beam emission position and emission angle that have already been determined. It is possible to prevent the deviation.

  As mentioned above, although embodiment of this invention has been described, this invention is not limited to the said embodiment, A various change is possible. For example, the light source of the light source module 1 is not limited to the semiconductor laser 11, and other light emitting elements such as light emitting diodes may be used as the light source, and the emitted light is not limited to the beam shape. As the collimator lens 123 provided in the lens unit 12, a ball lens, a drum lens, or the like may be used. Further, another lens may be provided in the lens unit 12 instead of the collimator lens 123. The platform 13 may also be formed of other materials such as heavy metal as long as the required thermal conductivity is satisfied.

  In the light source module 1, the pressed portion that is directly pressed from the outside when the angle reference surface 131 is pressed against the angle determining plate 23 is a module from the viewpoint of simplifying the structure for supplying power to the semiconductor laser 11. The electrode 14 is preferable, but it may be a part other than the module electrode 14 when electric power can be supplied by another method.

  The angle reference surface 131 does not need to be completely perpendicular to the optical axis 121 of the lens unit 12 and may be provided approximately perpendicularly so long as a predetermined emission angle of the light beam can be determined. . The angle reference plane 131 may be provided over the entire circumference of the lens unit 12 or may be provided at a plurality of locations around the lens unit 12.

It is a perspective view which shows the structure of the light source module which concerns on one embodiment. It is a top view of a light source module. It is a front view of a light source module. It is a left view of a light source module. It is a right view of a light source module. It is a disassembled perspective view which shows the structure of an optical unit. It is sectional drawing which shows the structure of an optical unit. It is a figure which shows the structure of an image recording device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Light source module 11 Semiconductor laser 12 Lens part 13 Platform 14 Module electrode 20 Mounting plate 24 Electric probe 29 Power supply source 121 Optical axis 122a Position reference plane 123 Collimator lens 131 Angle reference plane 201 Mounting opening 232 Arrangement plane

Claims (4)

A light source module attached to an opening of a predetermined mounting plate,
A light source;
A lens portion that receives light from the light source and is inserted into the opening of the mounting plate;
A structure for holding the light source and the lens unit;
With
The lens portion includes an outer surface that is parallel to the optical axis and inserted into the opening as a position reference surface that determines a light emission position relative to the mounting plate by fitting.
The structure is
An angle reference plane that determines a relative light emission angle with respect to the mounting plate by being in contact with the main surface of the mounting plate, which is a surface approximately perpendicular to the optical axis provided around the lens unit;
A pressed part that is substantially parallel to the optical axis on the side opposite to the lens part of the light source and pressed in a direction toward the angle reference plane;
Equipped with a,
The light source module pressed portion, wherein the Oh Rukoto the connected electrical terminal to the light source while being pressed by the connected electric probe to a power supply source. The light source module according to claim 1 ,
The mounting plate is connected to the power supply source;
The light source module, wherein the position reference surface or the angle reference surface is another electrical terminal connected to the light source. The light source module according to claim 1 or 2 ,
A light source module, wherein the light source is a semiconductor laser. The light source module according to any one of claims 1 to 3 ,
The light source module, wherein the lens unit includes a collimator lens.

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