JP2011059282A - Optical scanner and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical scanner and an image forming apparatus in which a face to be projected is prevented from being irradiated with stray light with a simple configuration. <P>SOLUTION: The optical scanner 1 includes: a movable plate 21 having a light reflecting part 211; and a package 3 having a light transmission window 32 having translucency and turnably houses the movable plate 21. The optical scanner 1 further has a shielding part 53 which prevents entering of the light reflected on a translucent window 32, among the light incident from the translucent window 32, to the scanning region of the light reflected on the light reflecting part 211. The shielding part 53 having a shape of a wall is disposed between a region in which the incident light passes through the light translucent window 32 and a region in which emitted light passes through the light translucent window 32 at planar view of the movable plate 21. A sidewall of the incident light side and a sidewall on the emission light side are respectively tilted toward the incident light side with respect to the thickness direction of the movable plate 21 which is in a static state. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an optical scanner and an image forming apparatus.

For example, as an optical scanner for drawing (displaying) a desired image by scanning light onto a projection surface such as a screen or a wall surface, a scanner composed of a torsional vibrator is known (for example, Patent Document 1). reference).
In Patent Document 1, a movable portion whose upper surface is a reflection surface, a frame body that supports the movable portion, and a pair that connects the movable portion and the frame body so that the movable portion can be rotated with respect to the frame body. An optical deflector having a plurality of axes is disclosed. In Patent Document 1, in order to prevent adhesion of dust and the like, the above-described optical deflector is accommodated in an airtight package including a lower lid and a light transmission window. Such an optical scanner rotates a movable part, reflects light (laser beam) emitted from a light source (not shown) by a light reflection surface, and scans the reflected laser beam onto a projection surface such as a screen. Then, a desired image is drawn on the projection surface.

  Here, the light emitted from the light source passes through the light transmission window before being reflected by the light reflecting surface. When the light passes through the light reflecting window, a part of the light is reflected on the upper or lower surface of the light reflecting window, and the reflected light (hereinafter also referred to as “stray light”) may be irradiated on the projection surface. . Since the stray light is not scanned by the light reflecting surface, it has a property of staying at a predetermined position on the projection surface, thereby reducing the image quality of the image drawn on the projection surface.

Therefore, conventionally, a technique for preventing the generation of stray light by forming an antireflection film on the surface of the light transmission window has been used. However, when drawing a full-color image, it is common to use light of three colors of red, blue, and green, and design an antireflection film that can prevent reflection of all these three lights. Is very difficult and very expensive. Further, even if an antireflection film is formed on the surface of the light transmission window, it is difficult to completely prevent the generation of stray light (that is, reflection of light at the light transmission window).
Therefore, in the optical scanner described in Patent Document 1, the light transmission window is inclined with respect to the movable portion (light reflecting surface) so that stray light is not irradiated onto the projection surface. However, there is a problem that the configuration of the optical scanner becomes complicated by providing the light transmission window inclined with respect to the movable portion (light reflection surface).

JP 2005-250307 A

  An object of the present invention is to provide an optical scanner and an image forming apparatus that can prevent stray light from being irradiated onto a projection surface with a simple configuration.

Such an object is achieved by the present invention described below.
The optical scanner of the present invention includes a plate-shaped movable plate including a light reflecting portion having light reflectivity,
A light transmissive window having a light transmissive property, and a package for rotatably accommodating the movable plate,
An optical scanner configured to rotate the movable plate so that light incident from the light transmission window is reflected by the light reflection unit, and the reflected light is scanned and emitted from the light transmission window. And
Of the incident light incident from the light transmission window, the light reflected by the light transmission window has a shielding part that prevents the light reflected by the light reflection part from entering the scanning region,
The shielding portion has a wall shape and is provided between a region where the incident light passes through the light transmission window and a region where the emitted light passes through the light transmission window in a plan view of the movable plate. The incident light side sidewall and the outgoing light side sidewall are each inclined toward the incident light side with respect to the thickness direction of the movable plate in a non-driven state.
As a result, it is possible to provide an optical scanner that can prevent stray light from irradiating the projection surface with a simple configuration.

In the optical scanner according to the aspect of the invention, it is preferable that the shielding portion extends in a direction parallel to the rotation center axis X of the movable plate.
Thereby, light can be scanned linearly. Therefore, the optical scanner can more easily draw a desired image on the projection surface.
In the optical scanner according to the aspect of the invention, it is preferable that the shielding portion extends in a direction orthogonal to the rotation center axis X of the movable plate.
Thereby, the light can be scanned symmetrically with respect to the rotation center axis in a plan view of the movable plate in the non-driven state. Therefore, the optical scanner can more easily draw a desired image on the projection surface.

In the optical scanner according to the aspect of the invention, it is preferable that a light absorption film having a light absorption property is provided on at least the side wall on the incident light side among the side walls of the shielding portion.
Thereby, since the light (stray light) whose path is blocked by the shielding portion is absorbed by the light absorption film, unintentional reflection of stray light and the like can be reliably prevented.
In the optical scanner according to the aspect of the invention, it is preferable that the shielding portion is made of silicon as a main material.
Thereby, a shielding part can be formed easily and with high precision.
In the optical scanner according to the aspect of the invention, it is preferable that each of the side walls on the incident light side and the side on the outgoing light side of the shielding portion is configured with a plane orientation <111> plane.
Thereby, the shielding part which inclines to the incident light side can be formed comparatively easily.

In the optical scanner according to the aspect of the invention, it is preferable that the shielding portion is provided on a surface of the light transmission window opposite to the movable plate.
Thereby, light (stray light) can be more reliably shielded by the shielding part without causing an increase in the size of the shielding part. In addition, for example, when the optical scanner is manufactured, the optical scanner can be manufactured by housing the movable plate in the package and then joining the shielding portion to the light transmission window, thereby simplifying the optical scanner manufacturing method. be able to.
In the optical scanner according to the aspect of the invention, it is preferable that the shielding portion constitutes a part of the package.
Thereby, the manufacturing cost of the optical scanner can be reduced.

The optical scanner of the present invention has a substrate having a plate shape and a pair of through-holes separated by a predetermined distance,
It is preferable that the shielding portion is configured by a region located between the pair of through holes of the substrate.
Thereby, a shielding part can be formed easily.

In the optical scanner of the present invention, one of the pair of through holes has a tapered shape in which a cross-sectional area gradually decreases from one surface side of the substrate toward the other surface side, and the other through hole is formed. It is preferable that the cross-sectional area has a tapered shape in which the cross-sectional area gradually increases from the one surface side to the other surface side of the substrate.
Thereby, the shielding part inclined in the predetermined direction can be formed more easily and with a small thickness.

In the optical scanner according to the aspect of the invention, it is preferable that the light transmission window has a plate shape and is parallel to the movable plate when the movable plate is not driven.
Thereby, the configuration of the optical scanner can be simplified. Further, for example, it is not necessary to incline the light transmission window with respect to the movable plate as in the above-described prior art, so that the manufacture of the optical scanner can be simplified.

An image forming apparatus of the present invention includes a plate-like movable plate including a light reflecting portion having light reflectivity,
A light transmissive window having a light transmissive property, and a package for rotatably accommodating the movable plate,
An optical scanner configured to rotate the movable plate so that light incident from the light transmission window is reflected by the light reflection unit, and the reflected light is scanned and emitted from the light transmission window. An image forming apparatus,
Of the incident light incident from the light transmission window, the light reflected by the light transmission window has a shielding part that prevents the light reflected by the light reflection part from entering the scanning region,
The shielding portion has a wall shape and is provided between a region where the incident light passes through the light transmission window and a region where the emitted light passes through the light transmission window in a plan view of the movable plate. And a side wall on the incident light side and a side wall on the outgoing light side are each provided with an optical scanner inclined toward the incident light side with respect to the thickness direction of the movable plate in a non-driven state. Features.
Thus, it is possible to provide an image forming apparatus including an optical scanner that can prevent stray light from being irradiated onto the projection surface with a simple configuration.

It is a top view which shows 1st Embodiment of the optical scanner of this invention. It is a top view which shows the base | substrate with which the optical scanner shown in FIG. 1 is provided. It is the sectional view on the AA line in FIG. It is the BB sectional view taken on the line in FIG. It is sectional drawing which shows the drive of the optical scanner shown in FIG. It is sectional drawing explaining the function of the shielding part which the optical scanner shown in FIG. 1 has. It is sectional drawing explaining the manufacturing method of the optical scanner shown in FIG. It is sectional drawing explaining the manufacturing method of the optical scanner shown in FIG. It is sectional drawing explaining the manufacturing method of the optical scanner shown in FIG. It is sectional drawing explaining the manufacturing method of the optical scanner shown in FIG. It is a fragmentary sectional top view which shows 2nd Embodiment of the optical scanner of this invention. It is a top view which shows the optical path of the light scanned with the optical scanner shown in FIG. It is sectional drawing which shows 3rd Embodiment of the optical scanner of this invention. 1 is a schematic diagram illustrating a configuration of an image forming apparatus of the present invention.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of an optical scanner and an image forming apparatus of the invention will be described with reference to the accompanying drawings.
<First Embodiment>
First, a first embodiment of the optical scanner of the present invention will be described.
FIG. 1 is a partial cross-sectional perspective view showing a first embodiment of the optical scanner of the present invention, FIG. 2 is a plan view showing a substrate provided in the optical scanner shown in FIG. 1, and FIG. 3 is AA in FIG. 4 is a sectional view taken along line BB in FIG. 1, FIG. 5 is a sectional view showing driving of the optical scanner shown in FIG. 1, and FIG. 6 is a shielding portion included in the optical scanner shown in FIG. FIG. 7 to FIG. 10 are sectional views for explaining the method of manufacturing the optical scanner shown in FIG. In the following, for convenience of explanation, the upper side in FIGS. 1 and 3 to 10 is referred to as “upper” and the lower side is referred to as “lower”.

  As shown in FIG. 1, the optical scanner 1 includes a base body 2 having a vibration system, a package 3 that houses the base body 2, a drive unit 4 that vibrates the vibration system, an incident light hole 51, and a reflected light hole 52. The stray light shielding member 5 is formed. As shown in FIG. 2, the base body 2 includes a pair of a movable plate 21 provided with a light reflecting portion 211, a support portion 22 that supports the movable plate 21, and a pair of the movable plate 21 and the support portion 22. It has connection parts 23 and 24. The optical scanner 1 having such a configuration rotates the movable plate 21 while torsionally deforming the connecting portions 23 and 24 by the driving means 4, and the light reflected by the light reflecting portion 211 is projected onto a projection surface such as a screen. By scanning, a desired image is drawn on the projection surface.

First, the base 2 will be described.
As shown in FIG. 2, the support portion 22 has a substantially rectangular frame shape in both outer shape and inner shape. Such a support portion 22 has a function of supporting the movable plate 21. The shape of the support portion 22 is not particularly limited as long as the movable plate 21 can be supported. For example, a part of the frame-like support portion 22 may be missing so that the inside and the outside communicate with each other. A pair of support portions 22 may be provided so as to face each other via the movable plate 21.

As shown in FIG. 2, a plate-like movable plate 21 is provided inside the support portion 22. The movable plate 21 is rectangular in plan view. In addition, it does not specifically limit as a planar view shape of the movable plate 21, A substantially circular shape, other polygons may be sufficient, and an irregular shape may be sufficient.
On the upper surface of the movable plate 21, a light reflecting portion 211 having light reflectivity is provided. On the contrary, a permanent magnet 41 is provided on the lower surface of the movable plate 21.
Each of the connecting portions 23 and 24 has a longitudinal shape and can be elastically deformed. Such connecting portions 23 and 24 connect the movable plate 21 and the support portion 22 so that the movable plate 21 can rotate with respect to the support portion 22. The pair of connecting portions 23 and 24 are provided coaxially, and the movable plate 21 rotates with respect to the support portion 22 with this axis as the rotation center axis X.

  Such a base | substrate 2 is comprised by making silicon into a main material, and the movable plate 21, the support part 22, and the connection parts 23 and 24 are integrally formed. Thus, the base | substrate 2 which has the outstanding vibration characteristic is comprised by comprising the base | substrate 2 by making silicon into a main material. Further, by using silicon as the main material, high-precision processing can be performed, and the base body 2 having a desired shape (desired vibration characteristics) can be obtained more reliably.

Next, the package 3 will be described.
The package 3 has a function of accommodating the base 2. As shown in FIGS. 3 and 4, such a package 3 includes a box-shaped main body 31 having a recess 311 opened on the upper surface, and a light transmission window 32 provided so as to cover (close) the opening of the recess 311. It consists of and.
The concave portion 311 formed in the main body 31 includes a first concave portion 311a that opens to the central portion excluding the edge portion on the upper surface of the main body 31, and a second concave portion that opens to the central portion excluding the edge portion of the bottom surface of the first concave portion. It is comprised by the recessed part 311b. That is, the recess 311 has a stepped portion 311c in the middle of its depth direction. By fixing (joining) the support portion 22 of the base body 2 to the stepped portion 311c, the base body 2 is fixed and accommodated in the package 3 in a state where the movable plate 21 is rotatable.
Such a main body 31 is composed mainly of, for example, various glass materials or silicon. Moreover, the main body 31 may be comprised by LTCC (low temperature sintering ceramics), for example.

The light transmission window 32 has a plate shape and is joined to the upper surface of the main body 31 so as to cover the opening of the recess 311 of the main body 31. Thereby, the inside of the package 3 can be hermetically sealed (that is, the hermetic internal space S can be defined).
The light transmission window 32 is provided to be parallel to the movable plate 21 (base 2) when the movable plate 21 is not driven. Thus, by making the light transmission window 32 parallel to the movable plate 21, the configuration of the optical scanner 1 can be simplified. Further, for example, since the light transmission window 32 does not need to be inclined with respect to the movable plate 21 as in the above-described prior art, the manufacture of the optical scanner 1 can be simplified and the cost can be reduced.

Such a light transmission window 32 guides light emitted from a light source (for example, a light source 500 described later shown in FIG. 6) installed outside the optical scanner 1 to the light reflection unit 211 in the package 3. In addition, in order to guide the light reflected by the light reflecting portion 211 to the outside of the package 3, it is made light transmissive, that is, substantially colorless and transparent.
The constituent material of the light transmitting window 32 is not particularly limited, and examples thereof include various glass materials such as quartz glass, Pyrex glass (“Pyrex” is a registered trademark), and Tempax glass.

  The method for joining the main body 31 and the light transmission window 32 is not particularly limited, and for example, the main body 31 and the light transmission window 32 may be joined via an adhesive. Further, for example, when the main body 31 is made of silicon and the light transmission window 32 is made of a glass material, these may be joined by anodic bonding. When the main body 31 is made of LTCC (low temperature fired ceramics) and the light transmission window 32 is made of a crow material, these are bonded by anodic bonding via a bonding layer made of silicon as the main material. May be. By bonding the main body 31 and the light transmission window 32 by anodic bonding, the package 3 having excellent mechanical strength can be obtained.

Next, the driving unit 4 will be described.
As shown in FIGS. 1, 3, and 4, the driving unit 4 includes a permanent magnet 41 provided on the movable plate 21 and a coil 42 that generates a magnetic field that acts on the permanent magnet 41. That is, the optical scanner 1 is a moving magnet type electromagnetically driven optical scanner. According to such a drive means 4, since a relatively large torque can be applied to the connecting portions 23 and 24, the movable plate 21 can be rotated stably (that is, with a desired amplitude and frequency). .

The permanent magnet 41 is fixed to the lower surface of the movable plate 21 via an adhesive, for example. The permanent magnet 41 has a longitudinal shape and is provided so as to extend in a direction orthogonal to the rotation center axis X. Such a permanent magnet 41 is magnetized in the longitudinal direction, and one side in the longitudinal direction is an S pole and the other side is an N pole. By providing the permanent magnet 41 so as to extend in a direction orthogonal to the rotation center axis X, both end portions of the permanent magnet 41 can be positioned away from the rotation center axis X. Therefore, a large torque can be applied to the movable plate 21 by the action of the magnetic field generated by the coil 42.
The permanent magnet 41 is not particularly limited, and for example, a magnet made of a hard magnetic material such as a neodymium magnet, a ferrite magnet, a samarium cobalt magnet, an alnico magnet, or a bonded magnet can be suitably used.
The coil 42 is provided on the bottom surface of the second recess 311 b formed in the main body 31 of the package 3 so as to face the movable plate 21. Thereby, the magnetic field generated by the coil 42 can be effectively applied to the permanent magnet 41. The coil 42 is electrically connected to a power source (not shown), and an alternating voltage is applied from the power source.

By such driving means 4, the movable plate 21 rotates as follows.
First, an alternating voltage is applied to the coil 42 by the power source. As a result, a state in which a first magnetic field is generated in which the upper side (movable plate 21 side) of the coil 42 is an N pole and the lower side is an S pole, and a second state where the upper side of the coil 42 is an S pole and the lower side is an N pole. The state in which the magnetic field is generated alternately and periodically.

  In the first electric field, as shown in FIG. 5A, the movable plate 21 is rotated around the rotation center axis X so that the N pole side of the permanent magnet 41 is attracted to the coil 42 and the S pole side is away from the coil 42. It rotates counterclockwise around the center (first state). On the contrary, in the second electric field, as shown in FIG. 5B, the movable plate 21 is rotated so that the south pole side of the permanent magnet 41 is attracted to the coil 42 and the north pole side is away from the coil 42. It rotates clockwise about the central axis X (second state). Such a 1st state and a 2nd state are repeated alternately, and the movable plate 21 rotates centering on the rotation center axis | shaft X. FIG.

Next, the stray light shielding member 5 will be described.
When the light emitted from the light source passes through the light transmission window 32, a part of the light is reflected by the upper surface 32a or the lower surface 32b of the light transmission window 32 and reflected (hereinafter, this light is also referred to as “stray light”). ) Is irradiated on the projection surface. The stray light shielding member 5 has a function of blocking the stray light path and preventing the projection surface from being irradiated with the stray light. Therefore, according to the optical scanner 1 having such a stray light shielding member 5, a desired image can be drawn on the projection surface without causing deterioration in image quality.

  As shown in FIGS. 1, 3, and 4, the stray light shielding member 5 is provided outside the package 3. More specifically, the stray light shielding member 5 is provided on the upper surface 32 a of the light transmission window 32. Such a stray light shielding member 5 has a plate shape. The stray light shielding member 5 is formed with two through holes penetrating in the thickness direction, that is, an incident light hole 51 and a reflected light hole 52. Since the incident light hole 51 and the reflected light hole 52 are formed, a shielding wall (shielding portion) 53 that partitions the holes 51 and 52 is formed between the holes 51 and 52.

In the present embodiment, the stray light shielding member 5 is composed of silicon as a main material. Thereby, as described later, the incident light hole 51 and the reflected light hole 52 (that is, the shielding wall 53) can be formed easily and with high accuracy.
The incident light hole 51 and the reflected light hole 52 are located above the movable plate 21 and are separated from each other by a predetermined distance in the direction orthogonal to the rotation center axis X (that is, the incident light hole 51 and the reflection light hole 51 are reflected). The light holes 52 are arranged in parallel (without communication). Of these holes 51, 52, the incident light hole 51 is a hole for guiding the light emitted from the light source to the light reflecting portion 211 of the substrate 2 through the light transmission window 32, and the reflected light hole 52 is This is a hole for guiding the light reflected by the light reflecting portion 211 to the outside of the package 3 through the light transmission window 32. The opening size of the incident light hole 51 and the reflected light hole 52 in plan view is not limited, but the incident light hole 51 may be formed smaller than the reflected light hole 52.

  The incident light hole 51 has a rectangular (square or rectangular) cross-sectional shape. Further, the incident light hole 51 has a tapered shape in which the cross-sectional area gradually increases from the upper surface 5 a to the lower surface 5 b of the stray light shielding member 5. In other words, the incident light hole 51 is positioned so as to be included in the lower opening 512 having a rectangular opening shape and the lower opening 512 in a plan view of the stray light shielding member 5 (in the central portion excluding the edge of the lower opening 512). And is formed of four side surfaces that are inclined with respect to the thickness direction of the stray light shielding member 5 and connect the lower opening 512 and the upper opening 511. .

One of the reflected light holes 52 has a rectangular cross-sectional shape and a tapered shape in which the cross-sectional area gradually decreases from the upper surface 5 a to the lower surface 5 b of the stray light shielding member 5. In other words, the reflected light hole 52 is positioned so as to be included in the upper opening 521 having a rectangular opening shape and the upper opening 521 in a plan view of the stray light shielding member 5 (in the central portion excluding the edge of the upper opening 521). The opening shape is formed of a rectangular lower opening 522 and four side surfaces that are inclined with respect to the thickness direction of the stray light shielding member 5 and connect the upper opening 521 and the lower opening 522. .
That is, the incident light hole 51 and the reflected light hole 52 are through holes having tapered shapes in opposite directions. A shielding wall (shielding portion) 53 is formed between the incident light hole 51 and the reflected light hole 52 so as to partition the holes 51 and 52.

  One side wall 531 of the shielding wall 53 is constituted by a side surface of the incident light hole 51 on the reflected light hole 52 side, and the other side wall 532 is a surface of the reflected light hole 52 on the incident light hole 51 side. It is configured. That is, the side walls 531 and 532 of the shielding wall 53 are inclined toward the incident light hole 51 side with respect to the thickness direction of the stray light shielding member 5. Further, it can be said that such a shielding wall 53 is located between the incident light incident on the light reflecting portion 211 and the reflected light reflected by the light reflecting portion 211.

  Here, as described above, the stray light shielding member 5 is made of silicon as a main material. However, each side surface of the incident light hole 51 and the reflected light hole 52 (that is, both side walls 531 of the shielding wall 53). 532) is constituted by a plane orientation <111> plane. As a result, as will be described later, for example, a silicon wafer having a plane orientation of <100> is anisotropically etched using an etching solution such as an aqueous KOH solution, so that the thickness of the stray light shielding member 5 can be relatively easily reduced. On the other hand, the incident light hole 51 and the reflected light hole 52 (that is, the shielding wall 53) having side surfaces that are inclined with respect to each other can be formed. Thus, by forming the structure using the crystallinity of silicon, the thin shielding wall 53 can be formed with high accuracy and with ease.

  In the present embodiment, the light absorption film 6 having light absorptivity is provided on the side wall 531 of the shielding wall 53. Thereby, as will be described later, the stray light L ′ whose path is blocked by the shielding wall 53 is absorbed by the light absorption film 6. Therefore, unintentional reflection of the stray light L ′ can be reliably prevented. Such a light absorbing film 6 is made of, for example, a metal, an alloy containing at least one member selected from the group consisting of chromium (Cr), molybdenum (Mo), tantalum (Ta), titanium (Ti), and tungsten (W), It is preferably composed of an oxide or a nitride. Thereby, the light absorption film 6 having excellent light absorption can be formed relatively easily.

Next, the function of such a stray light shielding member 5 will be described in detail.
As shown in FIG. 6, when the movable plate 21 is rotated (when the optical scanner 1 is driven), the light source 500 emits the light L in the direction orthogonal to the rotation center axis X in plan view of the light transmission window 32. To exit. The light L passes through the light transmission window 32 and reaches the light reflection portion 211, is reflected by the light reflection portion 211, passes through the light transmission window 32 again, and is scanned onto the projection surface 100 (in the following, The area through which the scanned light L passes is also referred to as “scanning area T”). When the light L passes through the light transmission window 32 toward the light reflection portion 211, a part of the light L is reflected by the upper surface 32a or the lower surface 32b of the light transmission window 32 and becomes stray light L ′. The stray light L ′ tends to travel in the direction of the scanning region T (projected surface 100), but a shielding wall 53 is formed in the middle of the optical path of the stray light L ′ (that is, to block the optical path of the stray light L ′). Therefore, the stray light L ′ is absorbed by the light absorption film 6 provided on the side wall 531 of the shielding wall 53 by hitting the shielding wall 53. Thereby, it is possible to reliably prevent the stray light L ′ from being applied to the projection surface 100 (the scanning region of the light L). As a result, according to the optical scanner 1, a desired image can be drawn on the projection surface 100 without causing a decrease in image quality with a simple configuration in which only the stray light shielding member 5 (shielding wall 53) is provided. .

Further, in the optical scanner 1, since the shielding wall 53 is inclined toward the incident light hole 51, the stray light L ′ can be more reliably blocked while suppressing the height of the shielding wall 53. Thereby, size reduction of the optical scanner 1 can be achieved.
In the optical scanner 1, since the side walls 531 and 532 of the shielding wall 53 are both inclined in the same direction with respect to the thickness direction of the light transmission window 32 (because the side walls 531 and 532 are parallel), the shielding wall 53. (The separation distance between the side walls 531 and 532) can be reduced. Here, although depending on the incident angle of the light L with respect to the light transmission window 32, the larger the thickness of the shielding wall 53, the wider the distance between the stray light shielding member 5 and the movable plate 21 (light reflecting portion 211). For example, the light L is incident from the incident light hole 51, reflected by the light reflecting portion 211, and cannot be emitted from the reflected light hole 52. In this respect, in the optical scanner 1, as described above, since the thickness of the shielding wall 53 can be reduced, the separation distance between the stray light shielding member 5 and the movable plate 21 (light reflecting portion 211) can be further shortened. Can do. Therefore, the size of the optical scanner 1 can be reduced. The thickness of the shielding wall 53 is not particularly limited, but is preferably about 100 μm or more and 500 μm or less.

In addition, as described above, in the optical scanner 1, a pair of through holes (that is, the incident light hole 51 and the reflected light hole 52) are formed in the plate-like stray light shielding member 5. A region (wall portion) that is located between the holes 51 and 52 is defined as a shielding wall 53. With such a configuration, the shielding wall 53 can be easily formed.
In particular, in the present embodiment, the incident light hole 51 is a tapered hole whose transverse area gradually increases from the upper surface 5a to the lower surface 5b of the stray light shielding member 5, and the reflected light hole 52 is the transverse area. Since the hole has a tapered shape that gradually decreases from the upper surface 5a to the lower surface 5b of the stray light shielding member 5, the shielding wall 53 inclined in a predetermined direction can be formed more easily.

  Further, as described above, in the optical scanner 1, the shielding wall 53 (stray light shielding member 5) is provided on the upper surface 32 a of the light transmission window 32. Thereby, the formation position of the shielding wall 53 is in the immediate vicinity of the place where the stray light L ′ is generated. Therefore, the stray light L ′ can be more reliably shielded by the shielding wall 53 without increasing the size of the shielding wall 53. In addition, for example, when the optical scanner 1 is manufactured, the optical scanner 1 can be manufactured if the stray light shielding member 5 is joined to the upper surface 32a of the light transmission window 32 after the base 2 is accommodated in the package 3. The manufacturing method of the scanner 1 can be simplified.

Further, as described above, in the optical scanner 1, the incident light hole 51 and the reflected light hole 52 are formed side by side in a direction orthogonal to the rotation center axis X. That is, the shielding wall 53 extends in a direction parallel to the rotation center axis X. Therefore, in order for the light L to pass through the light transmission window 32 to reach the light reflection unit 211, be reflected by the light reflection unit 211, pass through the light transmission window 32 again, and be scanned on the projection surface 100. The optical path of the light L when passing through the light transmitting window 32 and reaching the light reflecting portion 211 needs to be a direction orthogonal to the rotation center axis X in a plan view of the light transmitting window 32. Thus, when the light L in the direction perpendicular to the rotation center axis X is scanned by the optical scanner 1 in a plan view of the light transmission window 32, the light L can be scanned linearly. Therefore, according to the optical scanner 1, a desired image can be drawn on the projection surface 100 more easily.
The optical scanner 1 as described above can be manufactured, for example, as follows. Hereinafter, a method for manufacturing the optical scanner 1 will be described with reference to FIGS. 7 to 10. FIGS. 7, 8, and 10 are respectively shown in cross-sections corresponding to FIG. 3. It is shown in a cross-section corresponding to FIG.

[Manufacture of substrate 2]
As shown in FIG. 7A, first, a silicon substrate 200 for obtaining the base 2 is prepared. Then, as illustrated in FIG. 7B, a mask M <b> 1 having a shape corresponding to the planar view shape of the movable plate 21, the support portion 22, and the connection portions 23 and 24 is formed on the upper surface of the silicon substrate 200. Next, the silicon substrate 200 is etched through the mask M1, and then the mask M1 is removed. Thereby, as shown in FIG.7 (c), the board | substrate with which the movable plate 21, the support part 22, and each connection part 23 and 24 were formed integrally is obtained. As the mask M1, a resist, a nitride film, an oxide film, or the like can be used.

  As the etching method, for example, one or more of physical etching methods such as plasma etching, reactive ion etching, beam etching, and light-assisted etching, and chemical etching methods such as wet etching are combined. Can be used. Note that the same method can be used for etching in the following steps.

Next, as shown in FIG. 7D, a metal film is formed on the upper surface of the movable plate 21 to form a light reflecting portion 211. Thereby, the base 2 is obtained. The method of forming the metal film is not particularly limited, and is a vacuum plating, sputtering (low temperature sputtering), dry plating methods such as ion plating, wet plating methods such as electrolytic plating and electroless plating, thermal spraying methods, joining metal foils. Etc.
Next, as shown in FIG.7 (e), the permanent magnet 41 is fixed to the lower surface of the movable plate 21 via an adhesive agent. In addition, it is good also as the permanent magnet 41 by fixing a hard magnetic body to the lower surface of the movable plate 21 via an adhesive agent, and magnetizing this hard magnetic body after that.

[Manufacture of package 3]
As shown in FIG. 8A, first, a silicon substrate 300 for obtaining the main body 31 is prepared, and an oxide film mask having a shape corresponding to the shape of the first recess 311a in plan view is formed on the upper surface of the silicon substrate 300. M2 is formed. Next, as shown in FIG. 8B, a resist mask M3 having a shape corresponding to the plan view shape of the second recess 311b on the upper surface of the silicon substrate 300 and the surface (side surface and bottom surface) of the first recess 311a. Form. Next, the silicon substrate 300 is etched through the resist mask M3, and then the resist mask M3 is removed. Next, the silicon substrate 300 is etched through the oxide film mask M2, and then the oxide film mask M2 is removed. Thereby, as shown in FIG.8 (c), the main body 31 in which the recessed part 311 was formed is obtained. Next, as shown in FIG. 8D, the coil 42 is provided on the bottom surface of the recess 311 (second recess 311b).
On the other hand, the light transmission window 32 is obtained by processing a plate-like member made of glass such as quartz glass, Tempax glass, and Pyrex glass into a predetermined size.

[Manufacture of stray light shielding member 5]
As shown in FIG. 9A, first, a silicon wafer (silicon substrate) 400 having a <100> wafer surface is prepared. 9B, a nitride film mask M4 having a shape corresponding to the shape of the upper opening 521 of the reflected light hole 52 is formed on the upper surface of the silicon wafer 400, and the lower surface of the silicon wafer 400 is formed. Then, a nitride film mask M5 having a shape corresponding to the shape of the lower opening 512 of the incident light hole 51 is formed. Next, the silicon wafer 400 is etched by wet etching (anisotropic etching) using a KOH aqueous solution or the like through the nitride film masks M4 and M5. Thereafter, the nitride film masks M4 and M5 are removed. Next, a metal film such as chromium is formed on the side surface of the incident light hole 51 on the reflected light hole 52 side, and the light absorption film 6 is formed. Accordingly, as shown in FIG. 9C, the stray light shielding member 5 in which the incident light hole 51, the reflected light hole 52, and the shielding wall 53 are formed is obtained. The method of forming the metal film is not particularly limited, and is a vacuum plating, sputtering (low temperature sputtering), dry plating methods such as ion plating, wet plating methods such as electrolytic plating and electroless plating, thermal spraying methods, joining metal foils. Etc.

  Here, since the etching rate in the plane orientation <111> direction is much slower than the etching rate in the plane orientation <100> direction and the plane orientation <110> direction, the etching proceeds and the plane orientation <111> plane is exposed. Then, it behaves as if etching stopped. By utilizing such an anisotropic etching property, the tapered incident light hole 51 and the reflected light hole 52 as described above can be easily formed. Moreover, since the thickness of the shielding wall 53 can be determined by the alignment accuracy of the nitride film masks M4 and M5, it can be formed as a thin structure with high accuracy.

[Assembly of each part]
As shown in FIG. 10A, the support portion 22 of the base 2 is fixed (bonded) to the step portion 311 c of the main body 31 of the package 3. The fixing of the support portion 22 to the stepped portion 311c can be performed using, for example, an adhesive. Next, as shown in FIG. 10B, the light transmission window 32 and the main body 31 are joined so as to cover the upper opening of the main body 31. The light transmission window 32 and the main body 31 can be joined by, for example, anodic bonding. Thereby, the main body 31 and the light transmission window 32 are joined, and an internal space S having airtightness is formed inside the package 3.

Note that, for example, the internal space S can be brought into a reduced pressure state by performing this step under a reduced pressure, and the inner space S can be brought into a rare gas filling state by being performed in a rare gas atmosphere. it can. In what environment (atmosphere) this process is performed can be appropriately selected according to the characteristics required of the optical scanner 1.
Next, as shown in FIG. 10C, the stray light shielding member 5 is joined to the upper surface of the light transmission window 32. The method for joining the stray light shielding member 5 and the light transmission window 32 is not particularly limited, and for example, the stray light shielding member 5 and the light transmission window 32 can be joined by anodic bonding.
Through the above steps, the optical scanner 1 is obtained.

Second Embodiment
Next, a second embodiment of the optical scanner of the present invention will be described.
FIG. 11 is a partial sectional plan view showing a second embodiment of the optical scanner of the present invention, and FIG. 12 is a plan view showing an optical path of light scanned by the optical scanner shown in FIG. In the following, for convenience of explanation, the front side in FIG. 11 is referred to as “up”.

Hereinafter, the optical scanner of the second embodiment will be described focusing on the differences from the optical scanner of the above-described embodiment, and the description of the same matters will be omitted.
The optical scanner 1A according to the second embodiment of the present invention differs from the optical scanner of the first embodiment described above except that the arrangement of the incident light holes 51 and the reflected light holes 52 formed in the stray light shielding member 5 is different. It is almost the same. In FIG. 11, the same reference numerals are given to the same configurations as those in the above-described embodiment.
As shown in FIG. 11, the incident light hole 51 and the reflected light hole 52 are located above the movable plate 21, and are arranged in parallel at a predetermined distance in a direction parallel to the rotation center axis X. Yes. That is, the shielding wall 53 is provided so as to extend in a direction orthogonal to the rotation center axis X in the plan view of the light transmission window 32.

In such an optical scanner 1A, the shielding wall 53 extends in a direction orthogonal to the rotation center axis X. Therefore, in order for the light L to pass through the light transmission window 32 to reach the light reflection unit 211, be reflected by the light reflection unit 211, pass through the light transmission window 32 again, and be scanned on the projection surface 100. As shown in FIG. 12, the optical path of the light L when passing through the light transmitting window 32 and reaching the light reflecting portion 211 is set to a direction parallel to the rotation center axis X in plan view of the light transmitting window 32. There is a need. As described above, when the light scanner 1 scans the light L in the direction parallel to the rotation center axis X in the plan view of the light transmission window 32, the light L is the rotation center in the plan view of the light transmission window 32. It is possible to scan symmetrically with respect to the axis X. Therefore, according to the optical scanner 1, various corrections can be easily performed, and a desired image can be drawn on the projection surface 100 more easily. In such a configuration, the length of the reflected light hole 52 in the direction parallel to the rotation center axis X can be made shorter than the reflected light hole 52 of the first embodiment, for example. Therefore, the optical scanner 1 can be further reduced in size.
Also by such 2nd Embodiment, the effect similar to 1st Embodiment can be exhibited.

<Third Embodiment>
Next, a third embodiment of the optical scanner of the present invention will be described.
FIG. 13 is a cross-sectional view showing a third embodiment of the optical scanner of the present invention.
Hereinafter, the optical scanner of the third embodiment will be described focusing on the differences from the optical scanner of the above-described embodiment, and the description of the same matters will be omitted.

The optical scanner 1B according to the third embodiment of the present invention is substantially the same as the optical scanner 1 of the first embodiment described above except that the package configuration is different. In FIG. 13, the same components as those in the above-described embodiment are denoted by the same reference numerals.
As shown in FIG. 13, in the optical scanner 1 </ b> B of this embodiment, the stray light shielding member 5 constitutes a part of the package 3. In other words, a part (the lower surface 5b) of the stray light shielding member 5 is used to define the internal space S of the package 3. This will be described in detail below.

  The light transmission window 32 is joined to the lower surface 5 b of the stray light shielding member 5. More specifically, the light transmission window 32 covers the lower opening 512 of the incident light hole 51 and the lower opening 522 of the reflected light hole 52 so as to exclude the edge of the lower surface 5 b of the stray light shielding member 5 ( It is provided to close. A method for joining the light transmission window 32 and the stray light shielding member 5 is not particularly limited. For example, the light transmission window 32 is composed of a glass material as a main material, and the stray light shielding member 5 is composed of silicon as a main material. In some cases, bonding by anodic bonding is preferred. According to anodic bonding, these members can be bonded more firmly. Further, since the light transmission window 32 and the stray light shielding member 5 can be directly joined (that is, no other member such as an adhesive layer is interposed between the light transmission window 32 and the stray light shielding member 5), the light Unintentional absorption and refraction of L can be prevented.

  The stray light shielding member 5 to which the light transmission window 32 is bonded is bonded to the upper surface of the main body 31 at the edge of the lower surface 5b. As described above, the package 3 includes the main body 31, the light transmission window 32, and the stray light shielding member 5, and the internal space S is defined by these. A method for joining the stray light shielding member 5 and the main body 31 is not particularly limited. For example, when the main body 31 is made of LTCC and the stray light shielding member 5 is made of silicon as a main material, anodic bonding is used. It is preferable to join. According to anodic bonding, the stray light shielding member 5 and the main body 31 can be bonded more firmly.

By using the stray light shielding member 5 as a part of the package 3 as in the present embodiment, for example, the size of the light transmission window 32 can be reduced as compared with the first embodiment described above. It can be made lean. As a result, the manufacturing cost of the optical scanner 1 can be reduced.
According to the third embodiment, the same effect as that of the first embodiment can be exhibited.
The optical scanner as described above can be suitably applied to an image forming apparatus such as a projector, a laser printer, an imaging display, a barcode reader, and a scanning confocal microscope. As a result, an image forming apparatus having excellent drawing characteristics can be provided.

Specifically, a projector 9 as shown in FIG. 14 will be described. For convenience of explanation, the longitudinal direction of the screen SC is referred to as “lateral direction”, and the direction perpendicular to the longitudinal direction is referred to as “vertical direction”.
The projector 9 includes a light source device 91 that emits light such as a laser, a cross dichroic prism 92, a pair of optical scanners 93 and 94 according to the present invention (for example, an optical scanner having the same configuration as the optical scanner 1), And a fixed mirror 95.

The light source device 91 includes a red light source device 911 that emits red light, a blue light source device 912 that emits blue light, and a green light source device 913 that emits green light.
The cross dichroic prism 92 is configured by bonding four right-angle prisms, and is an optical element that combines light emitted from each of the red light source device 911, the blue light source device 912, and the green light source device 913.

  Such a projector 9 combines light emitted from each of the red light source device 911, the blue light source device 912, and the green light source device 913 based on image information from a host computer (not shown) by a cross dichroic prism 92, The synthesized light is scanned by the optical scanners 93 and 94, and further reflected by the fixed mirror 95, so that a color image is formed on the screen SC.

Here, the optical scanning of the optical scanners 93 and 94 will be specifically described.
First, the light combined by the cross dichroic prism 92 is scanned in the horizontal direction by the optical scanner 93 (main scanning). The light scanned in the horizontal direction is further scanned in the vertical direction by the optical scanner 94 (sub-scanning). Thereby, a two-dimensional color image can be formed on the screen SC. By using the optical scanner of the present invention as the optical scanners 93 and 94, extremely excellent drawing characteristics can be exhibited.
However, the projector 9 is not limited to this as long as it is configured to scan light with an optical scanner and form an image on an object. For example, the fixed mirror 95 may be omitted.

  Although the optical scanner and the image forming apparatus of the present invention have been described based on the illustrated embodiment, the present invention is not limited to this. For example, in the optical scanner and the image forming apparatus of the present invention, the configuration of each part can be replaced with an arbitrary configuration that exhibits the same function, and an arbitrary configuration can be added. For example, in the optical scanner and the image forming apparatus of the present invention, the above-described embodiments may be appropriately combined.

In the above-described embodiment, the light absorbing film is formed on the side surface of the incident light hole on the reflected light hole side. However, the present invention is not limited to this. For example, the incident light hole is formed on all side surfaces of the incident light hole. A light absorption film may be formed, and may also be formed on the side surface of the reflected light hole. Such a light absorbing film may be omitted.
In the above-described embodiment, the mode in which no film is formed on the upper surface and the lower surface of the light transmission window has been described. However, the present invention is not limited to this. For example, at least one of the upper surface and the lower surface of the light transmission window An antireflection film may be formed on the surface. As described above, even if the antireflection film is formed, the generation of stray light cannot be completely prevented, and in this case, the function of the shielding portion is exhibited.

  DESCRIPTION OF SYMBOLS 1, 1A, 1B ... Optical scanner 2 ... Base | substrate 21 ... Movable plate 211 ... Light reflection part 22 ... Support part 23, 24 ... Connection part 3 ... Package 31 ... Main body 311 ... Recessed part 311a ... ... 1st recessed part 311b ... 2nd recessed part 311c ... Step part 32 ... Light transmission window 32a ... Upper surface 32b ... Lower surface 4 ... Driving means 41 ... Permanent magnet 42 ... Coil 5 ... Stray light shielding 5a …… Upper surface 5b …… Lower surface 51 …… Incoming light hole 511 …… Upper opening 512 …… Lower opening 52 …… Reflected light hole 521 …… Upper opening 522 …… Lower opening 53 …… Shielding wall 531 532 …… Side wall 500 …… Light source 6 …… Light absorption film 9 …… Projector 91 …… Light source device 911 …… Red light source device 912 …… Blue light source device 913 …… Green light source device 92 …… Loss dichroic prism 93, 94 …… Optical scanner 95 …… Fixed mirror 100 …… Projected surface 200, 300 …… Silicon substrate 400 …… Silicon wafer L …… Light L ′ …… Stray light M1 …… Mask M2 …… Oxidation Film mask M3 ... Resist mask M4, M5 ... Nitride film mask S ... Internal space SC ... Screen X ... Rotation center axis

Claims (12)

A plate-like movable plate including a light reflecting portion having light reflectivity;
A light transmissive window having a light transmissive property, and a package for rotatably accommodating the movable plate,
An optical scanner configured to rotate the movable plate so that light incident from the light transmission window is reflected by the light reflection unit, and the reflected light is scanned and emitted from the light transmission window. And
Of the incident light incident from the light transmission window, the light reflected by the light transmission window has a shielding part that prevents the light reflected by the light reflection part from entering the scanning region,
The shielding portion has a wall shape and is provided between a region where the incident light passes through the light transmission window and a region where the emitted light passes through the light transmission window in a plan view of the movable plate. The incident light side sidewall and the outgoing light side sidewall are each inclined toward the incident light side with respect to the thickness direction of the movable plate in a non-driven state. Scanner.   The optical scanner according to claim 1, wherein the shielding portion extends in a direction parallel to the rotation center axis X of the movable plate.   The optical scanner according to claim 1, wherein the shielding portion extends in a direction orthogonal to the rotation center axis X of the movable plate.   4. The optical scanner according to claim 1, wherein a light absorption film having light absorption is provided on at least the side wall on the incident light side of the shielding portion.   The optical scanner according to any one of claims 1 to 4, wherein the shielding portion is made of silicon as a main material.   6. The optical scanner according to claim 5, wherein the incident light side sidewall and the outgoing light side sidewall of the shielding portion are each configured with a plane orientation <111> plane.   The optical scanner according to claim 1, wherein the shielding portion is provided on a surface of the light transmission window opposite to the movable plate.   The optical scanner according to claim 1, wherein the shielding part constitutes a part of the package. It has a plate shape and has a substrate on which a pair of through-holes separated by a predetermined distance are formed,
The optical scanner according to any one of claims 1 to 8, wherein the shielding portion is configured by a region located between the pair of through holes of the substrate.   One of the pair of through-holes has a tapered shape in which the cross-sectional area gradually decreases from one surface side to the other surface side of the substrate, and the other through-hole has a cross-sectional area that is The optical scanner according to claim 9, wherein the optical scanner has a tapered shape that gradually increases from the one surface side of the substrate toward the other surface side.   The optical scanner according to claim 1, wherein the light transmission window has a plate shape and is parallel to the movable plate when the movable plate is not driven. A plate-like movable plate including a light reflecting portion having light reflectivity;
A light transmissive window having a light transmissive property, and a package for rotatably accommodating the movable plate,
An optical scanner configured to rotate the movable plate so that light incident from the light transmission window is reflected by the light reflection unit, and the reflected light is scanned and emitted from the light transmission window. An image forming apparatus,
Of the incident light incident from the light transmission window, the light reflected by the light transmission window has a shielding part that prevents the light reflected by the light reflection part from entering the scanning region,
The shielding portion has a wall shape and is provided between a region where the incident light passes through the light transmission window and a region where the emitted light passes through the light transmission window in a plan view of the movable plate. And a side wall on the incident light side and a side wall on the outgoing light side are each provided with an optical scanner inclined toward the incident light side with respect to the thickness direction of the movable plate in a non-driven state. An image forming apparatus.

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