JP4914616B2 - Optical scanning module for optical information reader and method of making scanning mirror thereof - Google Patents

Description

The present invention is for an optical information reading apparatus that optically scans a reading object composed of patterns having different light reflectivities such as a barcode and a two-dimensional code, receives the reflected light, and reads information from a photoelectrically converted signal. The present invention relates to an optical scanning module and a method of creating a scanning mirror thereof .

As an optical information reading device, for example, a laser scanner that reads a barcode is initially expensive because the laser light emitting unit, lens, scanning mechanism, electric circuit, and the like constituting the optical scanning unit are expensive. Was also expensive. In recent years, these parts have also become inexpensive, and downsizing can be realized by technological innovation.
However, even in the housing of the laser scanner, the optical unit has to be a certain distance between the lens and the laser generator, which is the light emitting unit, and thus has become a bottleneck for miniaturization and thinning. For this reason, various techniques have recently been developed in order to realize a reduction in size and thickness of an optical scanning unit in an optical information reader.

For example, in the optical scanner device described in Patent Document 1, a special lens called a ball lens is used to maintain the accuracy of the optical unit while reducing the thickness of the optical scanner device (optical scanning device).
In addition, as can be seen in Patent Document 2, there is an example in which the entire housing is reduced in size by changing the arrangement of the light emitting unit and the lens to be different from the usual one.
Furthermore, for example, the optical scanning device described in Patent Document 3 attempts to reduce the size and thickness from the member level using semiconductor thin film technology.

JP 2005-106871 A JP 2003-295093 A JP 2004-264684 A

As described above, techniques for reducing the size and thickness of the optical scanning unit housed in the housing of the optical information reading apparatus are advancing day by day. However, the presence of a light emitting unit including a lens and a laser light source that takes a large space and a scanning mirror for scanning the laser light is an obstacle to making the optical scanning unit small.
Moreover, no matter how small and thin it can be, if it cannot be manufactured efficiently and at low cost, distribution as an industrial product is difficult.

The present invention has been made on the basis of the technical background as described above. The optical scanning unit for the optical information reader is modularized to further reduce the size and thickness, and the manufacture thereof is easy. The purpose is to be able to provide it at low cost.

An optical scanning module according to the present invention is an optical scanning module for an optical information reading device that optically scans a reading target composed of patterns having different light reflectivities, receives the reflected light, and reads information from a photoelectrically converted signal. In order to achieve the above object, the following configuration is provided.
That is, a substrate unit including a light emitting unit that emits light to be irradiated on a reading target, a movable scanning mirror that deflects and emits light emitted from the light emitting unit, and light emitted from the light emitting unit A reflection unit formed with a reflection surface for guiding to the scanning mirror, and a collimator unit including a collimator lens that collimates the light emitted from the light emitting unit and guided to the scanning mirror by the reflection surface. It is formed into a shape, and is laminated and joined together.

And the said reflection part is comprised by the 1st reflection part laminated | stacked between the said board | substrate part and the collimator part, and the 2nd reflection part laminated | stacked on the said collimator part, The 1st reflection part and 2nd A pair of reflecting surfaces that are inclined and opposed to each other are formed on the reflecting portion, and light emitted from the light emitting portion is reflected by one of the pair of reflecting surfaces of the first reflecting portion, and the collimator It led to the lens, constituting the light collimated by the collimator lens, so as to induce in the scanning mirror by the other of the pair of reflecting surfaces of the pair of reflecting surfaces of the second reflecting part and the first reflecting portion To do.

Alternatively, the light emitting unit that emits light to irradiate the reading target, and a movable scanning mirror that deflects and emits the light emitted from the light emitting unit, and the light emitting unit stacked on the substrate unit, A reflection part that forms a reflection surface for reflecting the light emitted from the part, and the light emitted from the light emitting part and reflected by the reflection surface is converted into parallel light and returned to the reflection surface again. The collimator part having the concave reflecting surface directed toward the scanning mirror may be formed in a wafer shape, and the stacked parts may be joined to each other.
The scanning mirror in each of the optical scanning modules may be cantilevered on the substrate portion by a bimorph portion in which layers made of materials having different thermal expansion coefficients are stacked.
The present invention further provides the following scanning mirror creation method for creating a scanning mirror provided in the optical scanning module.
That is, a sacrificial layer of polysilicon is deposited on the substrate, and a bimorph portion in which the lower layer is made of a material having a thermal expansion coefficient larger than that of the upper layer is deposited on the substrate so as to cover one end of the sacrificial layer. The mirror material is deposited on the entire sacrificial layer including the bimorph portion and plated, and the sacrificial layer is removed by etching, and one end of the mirror material is fixed on the substrate by the bimorph portion. A cantilever structure is formed.

  The optical scanning module for an optical information reading device according to the present invention is configured as a module in which all the components of the optical scanning unit are formed in a wafer shape and stacked and bonded, so that a significant reduction in size and thickness can be realized. And it can be manufactured efficiently and inexpensively.

Hereinafter, the best mode for carrying out the present invention will be specifically described with reference to the drawings.
[Configuration of First Embodiment]
First, the configuration of a first embodiment of an optical scanning module for an optical information reader according to the present invention will be described with reference to FIGS.
1 is a cross-sectional view showing the configuration of the optical scanning module, FIG. 2 is an exploded perspective view of the right side of FIG. 1 with the right side in front, and FIG. 3 is a perspective view of a completed state in which the respective parts (layers) are stacked and joined. FIG.

The optical scanning module 1 is formed in a rectangular parallelepiped shape, and is configured by stacking five layers of a substrate unit 10, a first reflection unit 20, a collimator unit 30, a second reflection unit 40, and a transparent cover unit 50.
The substrate unit 10 includes a laser radiating unit 11 that is a light emitting unit that radiates light to be radiated on a reading target, and a movable scanning mirror 12 that deflects and emits the light emitted by the laser radiating unit 11. ing. The scanning mirror 12 is provided in the substantially central part of the substrate part 10, and the laser emitting part 11 is provided in a biased manner on one side thereof.

The first reflection unit 20 is stacked on the substrate unit 10, and a pair of reflection surfaces 21 and 22 are formed on the inner surface facing the laser emission unit 11 and the scanning mirror 12. The reflecting surfaces 21 and 22 are both planar reflecting surfaces that are inclined upward in the opposite direction at an angle of 45 ° with respect to the inner surface (upper surface) of the substrate portion 10.
The collimator unit 30 is a convex lens that is laminated on the first reflecting unit 20 and converts the laser light emitted from the laser emitting unit 11 and reflected by one reflecting surface 21 of the first reflecting unit 20 into parallel light. 31, and a through hole window 32 is formed between the first reflecting portion 20 and the second reflecting portion 40.

  The second reflection unit 40 is stacked on the collimator unit 30 and guides the laser beam converted into parallel light by the collimator lens 31 to the scanning mirror 12 together with the other reflection surface 22 of the first reflection unit 20. Reflective surfaces 41 and 42 are formed. The reflection surfaces 41 and 42 are formed on the inner surface of the second reflection unit 40 so as to face the positions corresponding to the reflection surfaces 21 and 22 of the first reflection unit 20, and both are formed at an angle of 45 ° with respect to the upper surface. It is a planar reflecting surface that is inclined downward in the opposite direction.

The transparent cover part 50 is a flat layer made of a transparent material laminated on the second reflecting part 40. However, the transparent cover portion 50 can be omitted.
Each of these parts is formed in a wafer shape and joined together by a lamination technique to form a module as shown in FIG.
When the transparent cover portion 50 is provided, the space where the laser emitting portion 11, the scanning mirror 12, and the collimator lens 31 are arranged is sealed, so that dust, foreign matter, moisture, or the like enters from the outside and becomes dirty or deteriorated. Can be prevented.

In the laser emitting section 11 that emits laser light, a laser diode 112 and a monitor photodiode 113 are arranged on a submount 111 provided on the inner surface of the substrate section 10. The laser diode 112 is installed near the end closer to the reflecting surface 21 of the first reflecting unit 20 on the submount 111, and the monitor photodiode 113 for detecting the amount of light is arranged at the end closer to the scanning mirror 12. It is installed close to the department. Wirings 114 and 115 to the laser diode 112 and the monitor photodiode 113 are led out from the submount 111 through through holes formed in the substrate unit 10. A wiring 116 for driving the scanning mirror 12 is also led out through a through hole formed in the substrate unit 10. These wirings are referred to as through wirings.

  In the optical scanning module 1, the laser light emitted from the laser diode 112 of the laser emitting unit 11 is first reflected by one reflecting surface 21 of the first reflecting unit 20 as shown in FIG. The reflected light is deflected by 90 ° and directed toward the collimator lens 31 of the collimator unit 30, passes through the collimator lens 31, becomes parallel light, and is sequentially reflected by the reflection surfaces 41 and 42 of the second reflection unit 40, respectively. After being deflected, it is reflected by the other reflecting surface 22 of the first reflecting portion 20 and further deflected by 90 ° and guided to the scanning mirror 12. Then, the laser light reflected by the scanning mirror 12 passes through the transparent cover 50 and is emitted to the outside, and irradiates a reading target such as a barcode.

  Although details of the scanning mirror 12 will be described later, the scanning mirror 12 is cantilevered on the substrate unit 10 by the bimorph unit 103 so as to be swingable, and is approximately 45 ° as shown by a virtual line in FIG. The tilt angle changes by reciprocating vibration in the range of the angle θ around the tilted state. Then, the laser light guided from the reflecting surface 22 to the scanning mirror 12 parallel to the inner surface of the substrate unit 10 is reflected and deflected by the scanning mirror 12 and is transmitted through the transparent cover unit 50 to be emitted within an angle range of 2θ. The injection angle changes. Therefore, a scanning target such as a barcode can be optically scanned by irradiating the laser beam within a range corresponding to the distance to the barcode and the angle 2θ.

  Although a condensing lens and a light receiving element for receiving and photoelectrically converting reflected light from a reading target by the optical scanning are not shown, for example, a collimator unit 30 or a transparent cover unit 50 is included in the optical scanning module 1. A condensing lens for condensing the reflected light from the object to be read is also formed, and a light receiving element array such as a photodiode can be disposed on the inner surface of the substrate unit 10. Alternatively, a light receiving unit module including a condenser lens and a light receiving element can be integrally formed adjacent to the optical scanning module 1.

Further, in this embodiment, the reflecting part is configured by the first reflecting part 20 and the second reflecting part 40 that are formed in a pair of reflecting surfaces inclined in opposite directions, but the present invention is not limited to this. A reflection surface may be provided so that the light emitted from the laser radiation unit 11 can be guided to the scanning mirror 12 through the collimator lens 31. The configuration of the reflection unit is also changed according to the arrangement relationship of the laser radiation unit 11, the scanning mirror 12, and the collimator lens 31.

Next, a method for manufacturing this optical scanning module will be described.
[Method of forming a reflective portion having a reflective surface]
The layers of the first reflector 20 and the second reflector 40 are formed by, for example, silicon anisotropic wet etching.
FIG. 4 is a diagram for explaining the azimuth plane of the silicon substrate. FIGS. 4A to 4C show the (100) plane, the (110) plane, and the (111) plane on the left side with hatching. The right side shows the bonding state of silicon atoms in the silicon substrate with the orientation plane shown on the left side as the surface.

FIG. 5 shows a silicon anisotropic wet etching process.
As is well known, when a silicon member having an etching mask 26 made of SiO ₂ or SiN on a silicon substrate 25 is immersed in an etching solution such as trimethylammonium hydroxide (TMAH), the silicon single crystal has each orientation. The etching speed varies depending on the surface.
As shown in FIG. 4 , the etching speed differs depending on how the silicon atoms on the surface are bonded to the silicon atoms in the crystal.

  As shown in FIG. 4 (a), the most common silicon substrate has a (100) plane as its surface, and an anisotropic crystal is formed by opening a strip-shaped opening parallel to the (110) direction in the etching mask 26. When etching is performed, a V-shaped groove 27 surrounded by two (111) planes is formed as shown in FIG. The V-shaped groove 27 is continuously formed as shown in FIG. 5B, and undercut in the crystal direction following the outer periphery of the etching mask 26 as shown in FIG. As a result, a quadrangular frustum-shaped depression 28 is formed as shown in FIG.

  With this technique, the shapes of the silicon layers of the first reflecting portion 20 and the second reflecting portion 40 are formed. The inclined surfaces 28a and 28b, which are inclined to face each other in the opposite direction of the recess 28 shown in FIG. 5 (d), form a mirror-like surface due to the characteristics of silicon, but aluminum is used to increase the reflectance. Metal or gold may be deposited. The inclined surfaces 28a and 28b become the reflecting surfaces 21 and 22 or the reflecting surfaces 41 and 42, respectively.

[Method of forming collimator lens of collimator ]
The layer of the collimator unit 30 provided with the collimator lens 31 which is a convex lens is formed by a photoregistry flow method or a gray scale mask method. FIG. 6 shows the steps of the registry flow method.

As shown in FIG. 6A, a negative photoresist 36, which is a photosensitive resin, is applied to the surface of a substrate 35 made of quartz glass or the like. The substrate 35 is exposed (patterned) using a photomask 37 to burn the shadow onto the photoresist 36. Thereby, the photoresist 36 can region otherwise to have the photosensitive region, as shown in (b) of FIG. 6 by wet etching, it is possible to leave only the region 36a which is sensitive. By heating the substrate, the photoresist region 36a is melted and cured to form a microlens array shape 36b as shown in FIG. Further, by performing dry etching, the lens shape is transferred to a substrate 35 made of quartz glass or the like, and a microlens array 38 of convex lenses can be formed as shown in FIG.

Next, the gray scale mask method will be described with reference to FIG.
As shown in FIG. 7A, a positive photoresist layer 302 is applied on a substrate 301 made of quartz glass or the like to make a basic material. Next, exposure is performed through a gray scale mask 303 prepared in advance as shown in FIG. This gray scale mask is, for example, a circular mask as a whole, in which a dot pattern having a density that gradually decreases from the center toward the periphery is formed concentrically. In this case, in order to form a lens with the positive photoresist layer 302, the density of the dot pattern is changed in accordance with the curved surface shape of the lens. As a result, the exposure amount increases concentrically from the center toward the periphery.

Next, when the exposed photoresist layer 302 is developed, as shown in FIG. 7C, the photoresist layer 302 becomes thinner as the exposure amount increases, and the surface thereof is formed into a convex curved surface. At the same time, surface roughness may occur on the surface.
Therefore, the surface of the developed photoresist layer 302 is melted at a temperature equal to or higher than the melting point. The molten surface is deformed to be smooth due to the viscosity of the photoresist. Thereby, the surface of the photoresist layer can be formed into a desired three-dimensional lens shape.

By performing dry etching from the surface side of the photoresist layer 302, the lens shape can be transferred to a substrate 301 made of quartz glass or the like, and a convex lens 304 can be formed as shown in FIG.
Although the substrate 301 is shown thick in FIG. 7, it may be a desired thickness.
If any of the above methods is employed, the collimator unit 30 having the collimator lens 31 shown in FIG. 1 can be formed as a wafer-like lens layer. The through hole window 32 can be formed by etching or sand blasting.

[How to create a scanning mirror]
Next, a method of creating the scanning mirror 12 shown in FIG. 1 on a silicon wafer or SOI wafer will be described with reference to FIG.
As shown in FIG. 8A, a polysilicon sacrificial layer 102 is deposited on a glass layer 101 corresponding to the substrate of the substrate portion 10 in FIG. 1 in order to position a mirror material described later.

Next, as shown in FIG. 8B, a bimorph portion 103 in which layers made of materials having different thermal expansion coefficients are laminated on the glass layer 101 so as to cover one end portion of the sacrificial layer 102 is deposited. In this example, a silicon oxide (SiO ₂ ) layer 103a and an aluminum (Al) layer 103b are selected as materials having different thermal expansion coefficients. The combination of these materials is not limited to silicon oxide and aluminum as long as it has a property of being curved by internal stress.

Then, as shown in FIG. 8C, a mirror material (copper here) 104 is deposited on the entire sacrificial layer including on the bimorph portion 103. Plating is performed to deposit the mirror material 104 thickly.
Etching is performed to remove the sacrificial layer 102 when the mirror material 104 is fixed. As a result, as shown in FIG . This etching method is not particularly limited, but here, a dry etching method using XeF ₂ (xenon difluoride) is used.
In this state, the bimorph portion 103 forms a cantilever structure that fixes one end portion of the mirror material 104 to the glass layer 101. The bimorph structure can be displaced by residual stress.

That is, when the bimorph portion 103 is energized, the material generates heat due to the energization resistance, and the temperature rises as a heater. At this time, since the thermal expansion coefficient of the underlying aluminum layer 103b is greater than the thermal expansion coefficient of the upper layer of the silicon oxide layer 103a, displaced upward free end of the bimorph section 103, as shown in FIG. 8 (e) The mirror material 104 is lifted diagonally, and the angle changes depending on the magnitude of energization. It can also be designed to rise to approximately 45 ° at room temperature.
ρ: curvature when the temperature of the bimorph part increases by ΔT y: displacement of the tip of the bimorph y = 2ρsin2 (1 / 2ρ) is satisfied.

The substrate 10, the first reflection unit 20, the collimator unit 30, the second reflection unit 40, and the transparent cover unit 50 made of glass, acrylic resin, or the like are laminated and bonded to the wafer, followed by dicing. the go, constituting the optical scanning module 1.
For this wafer bonding, it is preferable to use an anodic bonding technique that is often used for bonding a silicon substrate or a glass substrate and a silicon substrate to form a laminated structure.

The anodic bonding will be briefly described. For example, after a glass substrate and a silicon substrate are thoroughly washed, they are superposed and heated to 300 to 500 ° C. When a voltage of 400 to 500 V is applied with the silicon substrate as the anode, the charges in the glass are separated and negative charges are attracted to the silicon side. At this time, an electric current flows with the movement of the electric charge, and a large attractive force due to the electrostatic force acts on the interface, so that the substrates are bonded to each other. When the voltage drop at the interface becomes equal to the applied voltage, the movement of the charge is terminated, the current stops flowing, and the bonding is completed.

[Second Embodiment]
Next, a second embodiment of the optical scanning module for an optical information reader according to the present invention will be described with reference to FIGS.
9 is a perspective view showing the optical scanning module in a see-through state, FIG. 10 is a sectional view along the longitudinal direction, and FIG. 11 is an arrangement relationship between the light emitting portion, the reflecting surface of the reflecting portion, and the scanning mirror, and the optical path of the laser light. FIG. In these drawings, portions corresponding to those in FIGS. 1 and 2 are denoted by the same reference numerals, and description thereof is omitted or simplified.

The optical scanning module 1 of the first embodiment described above has a five-layer structure, but the optical scanning module 2 of the second embodiment has a three-layer structure. Therefore, the size and thickness can be further reduced as compared with the first embodiment.
That is, as shown in FIGS. 9 and 10, the optical scanning module 2 includes three layers of a substrate unit 60, a reflection unit 70, and a collimator unit 80, which are formed in a wafer shape, stacked, and bonded to each other. Configured.

  On the substrate unit 60, there are disposed a light emitting unit 11 that emits light to be irradiated on a reading target, and a movable scanning mirror 12 that deflects and emits light emitted from the light emitting unit 11. However, in the optical scanning module 1 described above, the light emitting unit 11 and the scanning mirror 12 are arranged along the center line in the width direction of the substrate unit 10. However, in the optical scanning module 2, the scanning mirror 12 is arranged. Although the center line in the width direction is arranged so as to coincide with the center line in the width direction of the substrate part 60, the light emitting part 11 is shifted from the center line in the width direction of the substrate part 60 as clearly shown in FIG. The position is inclined with respect to the center line.

In addition, the bimorph part 103 that cantilever-supports the scanning mirror 12 with respect to the substrate part 60 supports the center part in the longitudinal direction on both sides in the width direction of the scanning mirror 12. Similarly to the case of the optical scanning module 1, the lower end portion may be supported by the scanning mirror 12 by the bimorph portion 103. The bimorph part 103 is configured by laminating two layers made of materials having different thermal expansion coefficients as in the first embodiment described above.

A reflective surface 71 is formed on the inner end surface of the light emitting unit 11 on the side facing the laser diode 112 in the reflective unit 70 with an upward inclination of about 45 ° with respect to the upper surface of the substrate unit 60.
A concave reflecting surface 81 having a shape of a part of a spherical surface, that is, a concave mirror, is formed on the inner surface of the collimator unit 80 made of a transparent material at a position facing the reflecting surface 71. Note that, by changing the angle of the light emitting unit 11, the angle between the optical axis of the laser light emitted from the laser diode 112 and reflected by the reflecting surface 71 toward the concave reflecting surface 81 and the optical axis of the concave reflecting surface 81 is changed. It is configured to be arbitrarily changed.
The space formed in the reflection unit 70, that is, the space in which the light emitting unit 11 and the scanning mirror 12 are accommodated, is sealed by the layers of the substrate unit 60, the reflection unit 70, and the collimator unit 80. The effect is the same as in the case of the first embodiment.

In this optical scanning module 2, as shown in FIG. 10 and FIG. 11, the laser light emitted from the laser diode 112 of the light emitting unit 11 is reflected upward by the reflecting surface 71 of the reflecting unit 70, and the collimator unit 80 is reflected by the concave reflecting surface 81, reflected by the concave reflecting surface 81, converted into parallel light, returned to the reflecting surface 71 again, reflected there in the horizontal direction, and guided to the scanning mirror 12. The laser light is reflected upward by the scanning mirror 12 and is emitted to the outside through the transparent flat plate portion of the collimator unit 80. When the scanning mirror 12 is swung in the direction indicated by the arrow V in FIG. 10, the emission direction of the laser light changes, and light scanning can be performed by irradiating the reading target within a required range.

The manufacturing method of each part of the optical scanning module 2 of the second embodiment is substantially the same as that of the first embodiment described above. As in the case of the above-described embodiment, each part formed in a wafer shape is stacked and integrated using a semiconductor integration process technology (anodic bonding or the like) or a micro electro mechanical system (MEMS) technology. By joining, an ultra-small and thin optical scanning module can be completed.

However, the manufacturing method of the concave reflecting surface 81 of the collimator unit 80 is different from the manufacturing method described with reference to FIG . 6 or FIG. 7 of the collimator lens 31 of the collimator unit 30 in the first embodiment described above. An example of the manufacturing process will be described.
First, as shown in FIG. 12A, a positive photoresist 802 is applied to one surface of a glass substrate 801 to a uniform thickness, and corresponds to a concave reflection surface forming portion parallel to the upper surface. A photomask 803 having a gray scale 803a in which the light transmittance is higher toward the center of the circular portion is arranged. And that after exposing by irradiation from above the photomask 803 light, by development, spherical recess 802a on the photoresist 802 as shown in the same figure (b) is formed.

Next, when dry etching is performed from the side of the photoresist 802, the photoresist 802 is first thinned, and the photoresist 802 disappears in the recess 802a, and the glass substrate 801 is etched into a spherical shape . as shown in), spherical recess 801a on the surface of the glass substrate 801 is formed, as shown in FIG. (d), the photoresist 802 of the other portions is also removed.
Then, as shown in FIG. (E), a aluminum film 804 with a uniform thickness on the entire surface including even recess 801a of the glass substrate 801.

Then again, a photoresist is applied to the entire part surface including a concave portion 804a of the aluminum film 804 is developed after exposure using a photomask, as shown in (f) of FIG. 12, the concave portion 804a Leave the photoresist 805 alone. Then, as shown in FIG. (G) by etching, after the removal of the aluminum film 804 other than the concave portion 804a which is covered by the photoresist 805, the photoresist is removed 805 in the concave portion 804a, Fig. As shown in (h), the collimator unit 80 provided with the concave reflecting surface 81 is completed.

  Also in this embodiment, the optical scanning module 2 collects and receives the reflected light from the reading target irradiated with the laser beam, and the optical scanning module 2 includes a condenser lens and a light receiving element for photoelectric conversion. It is possible to provide a light receiving unit module including a condensing lens and a light receiving element integrally with the optical scanning module 2 as in the case of the first embodiment. It is the same.

  The optical scanning module according to the present invention can be used in various optical information readers such as a barcode reader and a two-dimensional code reader, and can realize a reduction in size and thickness of a scanner housing. In addition, the optical axis of the optical system can be easily adjusted, variations are reduced, and the manufacturing process is simple and efficient, so that manufacturing costs can be greatly reduced. Furthermore, since the lens layer and the mirror layer (reflection layer) are laminated, variations in optical design can be expanded. Through wiring can be performed on the substrate portion, the evaluation test time can be reduced, and the wiring of LSI or the like can be simplified.

It is a sectional view showing the configuration of a first embodiment of the optical information reading apparatus for optical scanning module of the present invention. FIG. 2 is an exploded perspective view of the right side of FIG. 1 viewed from the left front side. FIG. 3 is a perspective view of a completed state in which respective parts (layers) shown in FIG. 2 are stacked and joined. It is explanatory drawing for demonstrating the azimuth | direction surface of a silicon substrate. It is a figure which shows the process of the silicon anisotropic wet etching used for preparation of the reflection parts 20 and 40 shown in FIG. It is a figure which shows the process of the registry flow method applicable to preparation of the collimator part 30 shown in FIG.

It is a figure which shows the process of the gray scale mask method applicable to preparation of the collimator part 30 shown in FIG. It is a figure which shows the preparation process of the scanning mirror 12 shown in FIG. The configuration of the second embodiment of the optical information reading apparatus for optical scanning module of the present invention is a perspective view showing in phantom state. It is sectional drawing which follows the longitudinal direction similarly. It is a top view which similarly shows the arrangement | positioning relationship of the light emission part, the reflective surface of a reflection part, and a scanning mirror, and the optical path of a laser beam. It is a figure which shows an example of the manufacturing process of the collimator part 80 shown in FIG.

Explanation of symbols

1: Optical scanning module 10 for optical information reader, 60: Substrate unit 11: Laser emitting unit (light emitting unit) 12: Scanning mirror
20: 1st reflection part 21,22: Reflection surface 30,80: Collimator part
31: Collimator lens 32: Through-hole window 40: Second reflector
41, 42: Reflection surface 50: Transparent cover portion 70: Reflection portion 71: Reflection surface 81: Concave reflection surface (concave mirror) 103: Bimorph portion 111: Submount 112: Laser diode
113: Monitor photodiode

Claims (4)

An optical scanning module for an optical information reading device that optically scans a reading object configured with patterns having different light reflectivities, receives the reflected light, and reads information from a photoelectrically converted signal,
A substrate unit comprising: a light emitting unit that emits light that irradiates the reading target; and a movable scanning mirror that deflects and emits the light emitted from the light emitting unit;
A reflection part formed with a reflection surface for guiding the light emitted from the light emitting part to the scanning mirror;
A collimator unit including a collimator lens that collimates the light emitted from the light emitting unit and guided to the scanning mirror by the reflecting surface;
Each is formed in the shape of a wafer, stacked and joined together,
The reflective part is composed of a first reflective part laminated between the substrate part and the collimator part, and a second reflective part laminated on the collimator part,
The first reflecting portion and the second reflecting portion each form a pair of reflecting surfaces that are inclined in opposite directions and face each other.
The light emitted from the light emitting unit is reflected by one reflecting surface of the first reflecting unit and guided to the collimator lens, and the light collimated by the collimator lens is reflected by a pair of reflections from the second reflecting unit. An optical scanning module configured to guide the scanning mirror by a surface and the other reflecting surface of the first reflecting portion. An optical scanning module for an optical information reading device that optically scans a reading object configured with patterns having different light reflectivities, receives the reflected light, and reads information from a photoelectrically converted signal,
A substrate unit comprising: a light emitting unit that emits light that irradiates the reading target; and a movable scanning mirror that deflects and emits the light emitted from the light emitting unit;
A reflective part formed on a reflective surface that reflects the light emitted from the light emitting part, and is laminated on the substrate part;
A collimator unit formed on the reflection unit, and formed with a concave reflection surface that makes the light radiated from the light emitting unit and reflected by the reflection surface into parallel light and then returns to the reflection surface to face the scanning mirror. ,
An optical scanning module, characterized in that each is formed in a wafer shape and the laminated parts are joined together. 3. The optical scanning module according to claim 1 , wherein the scanning mirror is cantilevered on the substrate part by a bimorph part in which layers made of materials having different coefficients of thermal expansion are stacked. . A scanning mirror creating method for creating the scanning mirror provided in the optical scanning module according to claim 3,
Depositing a sacrificial layer of polysilicon on the substrate;
A bimorph portion in which two layers made of a material having a lower thermal expansion coefficient than that of the upper layer is laminated on the substrate so as to cover one end portion of the sacrificial layer,
Depositing a mirror material on the entire sacrificial layer including on the bimorph portion to perform plating,
A method for producing a scanning mirror, wherein the sacrificial layer is removed by etching to form a cantilever structure in which one end portion of the mirror material is fixed on the substrate by the bimorph portion.

Images