Patent Description:
Patent Literature <NUM> discloses an optical scanning device having a MEMS optical deflector. The optical scanning device is attached to a temple (side support) on one side of a spectacles-type head mount and emits scanning light from the MEMS optical deflector toward lenses and half mirrors arranged toward the front (front frame) of the spectacles.

According to the schematic diagram of Patent Literature <NUM>, the lens and the half mirror are mounted on the temple in addition to the optical scanning device, and the optical scanning device faces the half mirror with the lens interposed therebetween. Laser light emitted from the optical scanning device scans on the half mirror along the mirror surface thereof, is reflected by the mirror surface, and projects an image onto the retina of a user's eye.

Patent Literature <NUM>: <CIT> Documents <CIT>, <CIT>, <CIT>, and <CIT> are prior art documents for the present invention.

Patent Literature <NUM> does not disclose in what positional relationship, the light source, the MEMS optical deflector, and the substrate are mounted in the optical scanning device specifically.

In the previous <CIT> (hereinafter referred to as "prior application"), the applicant discloses an optical scanning device which mounts a light source emitting a light beam and a MEMS optical deflector incident with the light beam from the light source on the same substrate, and generates by optical elements, an optical path causing light emitted from the light source to enter a rotating mirror of the MEMS optical deflector. According to the optical scanning device, the distance between both of the light source and the MEMS optical deflector can be reduced by mounting both on the same substrate, and the optical scanning device can be significantly downsized.

When the light source and the MEMS optical deflector are mounted on the same substrate, the optical elements (e.g., mirrors) which generate the optical path of the light beam from the light source to the MEMS optical deflector need to accurately adjust the inclination angle relative to the optical path, but there is a limit to the range in which the inclination angle can be adjusted. On the other hand, the light source is mounted on the substrate so that the emission direction becomes a predetermined direction (e.g., a direction perpendicular to the substrate), but a deviation will occur.

When the deviation becomes large, it becomes difficult to deal with it by adjusting the inclination angle of the optical element.

An object of the present invention is to provide an optical scanning device and a manufacturing method thereof which, even if the direction of emission of a light beam from a light source deviates and the light source is mounted on a substrate, can compensate for the deviation.

There is provided an optical scanning device of the present invention which includes:.

There is provided a method for manufacturing an optical scanning device of the present invention, including:.

According to the present invention, a relative inclination angle between a bottom plate and a substrate is defined by a fitting angle at which at least one of a through hole portion of the substrate and a columnar protruding portion is fitted by plastic deformation so that the relative inclination angle becomes appropriate. As a result, even if the direction of emission of a light beam from a light source deviates and the light source is mounted on the substrate, it is possible to compensate for the deviation.

A plurality of preferred embodiments of the present invention will be described in detail with reference to the drawings. It goes without saying that the present invention is not limited to the following embodiments. In addition to the following embodiments, the present invention includes various configuration modes within the scope of the technical idea of the present invention. The same reference numerals are attached to the same elements through all the drawings.

<FIG> is a plan view of an optical scanning device <NUM>, <FIG> is a view taken along arrow 1B in <FIG>, <FIG> is a view taken along arrow 1C in <FIG>, and <FIG> is a view taken along arrow 1D in <FIG>. Incidentally, <FIG> show the optical scanning device <NUM> with a cover <NUM> (one-dot chain line in <FIG>) removed.

The optical scanning device <NUM> includes a support frame body <NUM>. The support frame body <NUM> has an L-shaped cross-sectional contour, and has a bottom plate portion 13a and an uprising plate portion 13b which are vertically connected. A substrate <NUM> is rectangular and fixed to an upper surface of the bottom plate portion 13a through a columnar protruding portion <NUM> interposed therebetween.

For convenience of description, a three-axis orthogonal coordinate system is defined. An X-axis and a Y-axis are defined as axes in the directions parallel to the longitudinal direction (direction parallel to the long side) and the lateral direction (direction parallel to the short side) of the substrate <NUM>, respectively. A Z-axis is defined as an axis parallel to the uprising direction of the uprising plate portion 13b from the substrate <NUM>.

In the optical scanning device <NUM>, scanning light is emitted from the left side of <FIG>, i.e., from the negative end of the optical scanning device <NUM> in the X-axis direction. Therefore, in the X-axis, the negative side and the positive side will be appropriately referred to as the front and rear of the optical scanning device <NUM>, respectively. Further, since the positive side and the negative side in the Z-axis direction are respectively taken as an upper surface and a lower surface in the substrate <NUM>, the positive side and the negative side in the Z-axis direction will be appropriately defined as above and below the optical scanning device <NUM>.

A VCSEL <NUM> and a MEMS optical deflector <NUM> are mounted on the upper surface of the substrate <NUM> with the X-axis direction as an arrangement direction. The VCSEL <NUM> has an emission unit <NUM> on its upper surface and emits laser light upward in parallel to the Z-axis direction from the emission unit <NUM>. The MEMS optical deflector <NUM> directs a mirror surface of a rotating mirror <NUM> upward in the Z-axis direction.

Incidentally, in <FIG>, Cn indicates a straight line including a line segment connecting the emission unit <NUM> as the center of the VCSEL <NUM> and the center of the MEMS optical defector <NUM> when viewed from the top of the substrate <NUM> (also viewing the substrate <NUM> in plan). Hereafter, this straight line will be referred to as a "center line Cn" as appropriate.

Incidentally, although the MEMS optical deflector <NUM> is a two-dimensional scanning MEMS optical deflector in the present embodiment, it may be a one-dimensional scanning MEMS optical deflector. The configuration of the MEMS optical deflector itself is known in various ways. For example, the MEMS optical deflectors described in <CIT> (two-dimensional scanning MEMS optical deflector) and <CIT> (one-dimensional scanning MEMS optical deflector) are selected.

The substrate <NUM> has two through hole portions <NUM> (<FIG>). Each through hole portion <NUM> penetrates the substrate <NUM> in its thickness direction and is circular in cross section. A specific positional relationship of the plurality of through hole portions <NUM> in the substrate <NUM> will be described later.

<FIG> is a side view of a support frame body <NUM>, and <FIG> is a perspective view of the support frame body <NUM>. The configuration of the support frame body <NUM> will be described with reference to <FIG> and <FIG>.

The uprising plate portion 13b of the support frame body <NUM> has an inclined groove <NUM> and a through hole <NUM>. The inclined groove <NUM> has a rectangular cross section and opens obliquely rearward upward along the side contour of the uprising plate portion 13b. A bottom surface of the inclined groove <NUM> is formed of an inclination surface inclined at <NUM>° with respect to the substrate <NUM>. The through hole <NUM> is formed as a cylindrical hole penetrating through the uprising plate portion 13b in the Y-axis direction.

Incidentally, the support frame body <NUM> of <FIG> is modified in structure of the uprising plate portion 13b from the support frame body <NUM> shown in each of <FIG> and <FIG>. Specifically, the support frame body <NUM> of <FIG> is provided with a side protruding portion <NUM> which protrudes sideways, i.e., toward the bottom plate portion 13a at the maximum height portion of the uprising plate portion 13b. The top surface of the side protruding portion <NUM> contacts an inner surface of a ceiling portion of the cover <NUM> (<FIG>) and holds the cover <NUM>.

Two columnar protruding portions <NUM> are fixed to the upper surface of the bottom plate portion 13a. Each columnar protruding portion <NUM> is set at a position where it can be inserted into the corresponding through hole portion <NUM> when the substrate <NUM> is placed on the bottom plate portion 13a. The columnar protruding portion <NUM> has a shape which tapers toward its tip and is formed in a conical shape, for example.

Description will be made about a plate-like mirror <NUM> and a rotary type mirror <NUM>. In the X-axis direction, the center of the width (length in side view in <FIG>) of the inclination surface (bottom surface) of the inclined groove <NUM> is located at the same position as the emission unit <NUM> of the VCSEL <NUM>. In the X-axis direction, a center line Cl (<FIG>) of the cylindrical hole of the through hole <NUM> is positioned between the VCSEL <NUM> and the rotating mirror <NUM> of the MEMS optical deflector <NUM> in the X-axis direction. In the Z-axis direction, the center of the length of the inclination surface of the inclined groove <NUM> and the center line of the cylindrical hole of the through hole <NUM> are located at the same position, that is, at the same height from the substrate <NUM>.

The plate-like mirror <NUM> is made of a rectangular plate-like member and has one end adhered to a slope portion of the inclined groove <NUM> in a cantilevered state with an adhesive member such as a resin with the lower plate surface thereof used as a mirror surface. The plate thickness of the plate-like mirror <NUM> is set substantially equal to the depth of the inclined groove <NUM>.

The plate width (length in side view in <FIG>) of the plate-like mirror <NUM> is slightly shorter than the width (length in side view in <FIG>) of the inclined groove <NUM>. Therefore, before one end of the plate-like mirror <NUM> is adhered to the inclined groove <NUM>, that is, in a state before the one end is fixed, the plate-like mirror <NUM> is slightly displaceable in the direction of the slope of the bottom surface within the inclined groove <NUM> and is capable of changing the angle of rotation around the axial line parallel to the Y-axis. Such a change enables adjustment of the orientation of the mirror surface of the plate-like mirror <NUM> when manufacturing the optical scanning device <NUM>.

The rotary type mirror <NUM> has a flat plate-like mirror portion <NUM> and a cylindrical fitting end portion <NUM> which is coupled to one end of the mirror portion <NUM> and fits into the through hole <NUM>. The size (diameter) of the fitting end portion <NUM> is slightly smaller than the size of the through hole <NUM>. Therefore, before adhesion of the fitting end portion <NUM> to the through hole <NUM>, i.e., in a state before fixing thereof, the rotary type mirror <NUM> is rotatable about the center line Cl of the through hole <NUM> while fitting the fitting end portion <NUM> into the through hole <NUM>, and can be tilted within a predetermined inclination angle range from a state in which the center line of the rotary type mirror <NUM> is aligned with the center line Cl of the through hole <NUM>. Therefore, the rotary type mirror <NUM> is rotatably displaceable in a larger angle range than the plate-like mirror <NUM>. Such a rotatable and tiltable configuration enables adjustment of the orientation of the mirror surface of the mirror portion <NUM> when the optical scanning device <NUM> is manufactured. After the adjustment, the fitting end portion <NUM> is adhered and fixed with an adhesive member such as a resin.

The rotating mirror <NUM> of the MEMS optical deflector <NUM> is not positioned directly below the rotary type mirror <NUM> with respect to the rotary type mirror <NUM> but is positioned on the front side, i.e., on the negative side with respect to the rotary type mirror <NUM> in the X-axis direction. As will be described later, this configuration contributes to causing a light beam Lp from the optical scanning device <NUM> to be emitted obliquely forward rather than perpendicular to the substrate <NUM> in regard to its emission direction. Further, this configuration ensures that when the optical scanning device <NUM> is attached to the temple of a spectacle body as a video scanning device of smart glasses, the light emitted from the optical scanning device <NUM> reaches the lens inner surface of the spectacle body without being interfered by the user's face from a slight gap between an imaging device and the user's face (<FIG>).

<FIG> is a perspective view of the substrate <NUM> mounted with the VCSEL <NUM> as viewed obliquely from above. A terminal row module <NUM> is fixed onto the upper surface of the substrate <NUM> along a rear edge of the substrate <NUM> and protrudes from the upper surface of the substrate <NUM>. Feeder lines and signal lines connected to the VCSEL <NUM> and the VCSEL <NUM> and the MEMS optical deflector <NUM> in the optical scanning device <NUM> are collected at inside terminals of the terminal row module <NUM> and connected to the outside via outside terminals which are in a relationship of being paired with the inside terminals. The terminal row module <NUM> protrudes from the upper surface of the substrate <NUM> by a predetermined height.

Description will be made in detail about the positions of the two columnar protruding portions <NUM>. When the substrate <NUM> is in plan view (also viewed from above), the center line Cn is parallel to the uprising plate portion 13b. The MEMS optical deflector <NUM> is larger than the VCSEL <NUM> in size in the lateral direction (Y-axis direction) of the bottom plate portion 13a which is substantially rectangular in plan view.

The columnar protruding portion <NUM> on the front end side is positioned on the front side of the MEMS optical deflector <NUM> in the longitudinal direction (X-axis direction) of the bottom plate portion 13a and in vicinity of the side edge on the uprising plate portion 13b side in the lateral direction (Y-axis direction). The columnar protruding portion <NUM> on the rear end side is positioned on the side opposite to the columnar protruding portion <NUM> on the front end side with respect to the VCSEL <NUM> in the lateral direction between the VCSEL <NUM> and the terminal row module <NUM> in the longitudinal direction.

In <FIG>, a thick broken line from which Lp is drawn indicates the optical path of the light beam Lp. Incidentally, the light beam Lp emitted from the emission unit <NUM> of the VCSEL <NUM> is laser light that has been sufficiently weakened to a level which does not harm the human eyes.

The light beam Lp is emitted from the emission unit <NUM> of the VCSEL <NUM> perpendicularly to the substrate <NUM> and upward (positive direction in the Z-axis direction). When the light beam Lp enters the plate-like mirror <NUM>, it is reflected by the plate-like mirror <NUM>, and the direction thereof is changed to be parallel to the X-axis as the direction in which the VCSEL <NUM> and the emission unit <NUM> on the upper surface of the substrate <NUM> are arranged and to be the negative side of the X-axis. Then, after the light beam travels forward (negative side of the X-axis) parallel to the X-axis, the light beam enters the obliquely downward mirror surface of the mirror portion <NUM> of the rotary type mirror <NUM>.

The inclination angle of the mirror portion <NUM> with respect to the substrate <NUM> is smaller than <NUM>°. Therefore, the light beam Lp reflected by the mirror portion <NUM> descends obliquely forward without descending to the substrate <NUM> in parallel to the Z-axis direction, that is, in the direction perpendicular to the substrate <NUM>, and enters the center of the rotating mirror <NUM> of the MEMS optical deflector <NUM>.

The rotating mirror <NUM> rotates two-dimensionally. Therefore, the light beam Lp incident on the rotating mirror <NUM> becomes scanning light for two-dimensional scanning and travels obliquely forward and upward from the rotating mirror <NUM>.

<FIG> is an explanatory view of deviations in the emission direction when the VCSEL <NUM> is mounted on the substrate <NUM> with an inclination. <FIG> illustrates VCSELs 17a, 17b, and 17c mounted on the substrate <NUM> at different angles as an example of mounting the VCSEL <NUM> on the substrate <NUM>.

The VCSEL 17a is mounted on the substrate <NUM> so that the emission direction of the light beam Lp is the direction parallel to the Z-axis, whereas the VCSELs 17b and 17c are mounted on the substrate <NUM> so that the light beams Lp are inclined to the opposite sides mutually with respect to the VCSEL 17a. For this reason, the light beam Lp from the emission unit <NUM> is emitted vertically above the substrate <NUM>, while the light beams are emitted from the VCSELs 17b and 17c in a direction inclined with respect to the Z-axis. That is, the mounting angle of the VCSEL <NUM> to the substrate <NUM> has errors and irregularities, and the direction of emission of the light beam Lp from the VCSEL <NUM> is displaced from directly above as indicated by arrows As.

<FIG> is an explanatory view of compensation by adjusting the inclination angle of the plate-like mirror <NUM> with respect to the deviation in the emission direction of the light beam Lp from the emission unit <NUM>. As will be described later, when the optical scanning device <NUM> is manufactured, the plate-like mirror <NUM> and the rotary type mirror <NUM> are adjusted in inclination angle whey they are assembled to the support frame body <NUM>. However, there is a limit to a compensable range by adjustment of the inclination angle of the plate-like mirror <NUM> for the deviation in the direction in which the light beam Lp is emitted from the emission unit <NUM>, and compensation for the deviation which exceeds the limit becomes difficult.

In <FIG>, an arrow Am indicates that the emission direction of the light beam Lp from the emission unit <NUM> of the VCSEL <NUM> has been displaced beyond a limit value from directly above. Bw indicates that adjusting the mounting angles of the plate-like mirror <NUM> and the rotary type mirror <NUM> with respect to the uprising plate portion 13b when the optical scanning device <NUM> is manufactured makes it difficult to compensate for the deviations in the direction of light-beam emission from the emission unit <NUM>.

Main parts of a method for manufacturing the optical scanning device <NUM> will be described below in order of steps. <FIG> is a view showing a step of assembling the substrate <NUM> to the support frame body <NUM>. In <FIG>, the VCSEL <NUM> and the MEMS optical deflector <NUM> have already been mounted on the substrate <NUM>. The VCSEL <NUM> is inclinedly mounted on the substrate <NUM>. This inclination is indicated by the arrow Am in <FIG>.

In <FIG>, an arrow A1 indicates the direction in which the substrate <NUM> is assembled to the bottom plate portion 13a of the support frame body <NUM>. The substrate <NUM> is moved downward vertically to the bottom plate portion 13a from above the bottom plate portion 13a, that is, in the direction of the arrow A1 so that the columnar protruding portions <NUM> of the bottom plate portion 13a are inserted into the respective through hole portions <NUM>.

<FIG> is a state diagram when starting to adjust the inclination direction of the substrate <NUM> with respect to the bottom plate portion 13a. After each columnar protruding portion <NUM> of the bottom plate portion 13a is inserted into the through hole portion <NUM>, the VCSEL <NUM> is set to a lightening state to emit the light beam Lp from the emission unit <NUM>. A beam profiler <NUM> is arranged above the VCSEL <NUM> and inspects the incident position of the light beam Lp emitted from the emission unit <NUM>. That is, a light spot Sp is projected on a display <NUM> of the beam profiler <NUM>. A target position <NUM> of the light spot Sp is shown in the center of the display <NUM>. When the light beam Lp emitted from the emission unit <NUM> of the VCSEL <NUM> is vertically upward with respect to the bottom plate portion 13a, the light spot Sp overlaps the target position <NUM>.

An adjustment operator adjusts the inclination angle of the substrate <NUM> with respect to the bottom plate portion 13a so that the light spot Sp moves in the direction of an arrow Ac on the display <NUM> and overlaps the target position <NUM>.

The columnar protruding portion <NUM> has a conical shape which tapers toward the tip (upper end) as its original shape. On the other hand, the through hole portion <NUM> of the substrate <NUM> has a circular shape in plan view, that is, a circular cross-sectional shape. The diameter of a base (lower end) of the columnar protruding portion <NUM> is larger than diameter (diam) of the through hole portion <NUM>.

Since the columnar protruding portion <NUM> has the tapered conical shape, the leading end of the columnar protruding portion <NUM> smoothly enters the through hole portion <NUM> from the lower end of the through hole portion <NUM>. Then, a portion of the columnar protruding portion <NUM> having the same diameter as that of the through hole portion <NUM> abuts against the lower end of the through hole portion <NUM> and is blocked from further entry. Since the diameters of the plurality of through hole portions <NUM> are the same as each other, and the plurality of columnar protruding portions <NUM> are the same in size and shape, the substrate <NUM> becomes parallel to the bottom plate portion 13a when the columnar protruding portion <NUM> abuts against the lower end of the through hole portion <NUM> and is blocked from entering the through hole portion <NUM>.

However, since the VCSEL <NUM> is not horizontal to the substrate <NUM> and is mounted thereon with inclination thereto, the light beam Lp emitted from the emission unit <NUM> has a considerable deviation with respect to the original emission direction in this state. Therefore, in a state (initial state) in which the through hole portion <NUM> of the substrate <NUM> is fitted with the columnar protruding portion <NUM> of the bottom plate portion 13a from below the through hole portion <NUM>, the substrate <NUM> is parallel to the bottom plate portion 13a. However, when the light beam Lp emitted from the emission unit <NUM> of the VCSEL <NUM> is inspected by the beam profiler <NUM>, the light spot Sp is displayed at a position distant from the target position <NUM> on the display <NUM>.

Hereinafter, the plane of the substrate <NUM> when the substrate <NUM> is parallel to the bottom plate portion 13a as a base plate is referred to as a "reference plane". The reference plane is a plane parallel to the X-axis and the Y-axis. Incidentally, the bottom plate portion 13a fits into a lower opening of the cover <NUM> (<FIG>) at its peripheral edge to configure a package of the optical scanning device <NUM>. In the initial state, the substrate <NUM> is in the reference plane.

<FIG> is an explanatory view of the work of correcting the emission direction from the emission unit <NUM> of the VCSEL <NUM>. The substrate <NUM> is made of a material which is relatively harder than the columnar protruding portion <NUM>. For example, the substrate <NUM> is of epoxy resin, and the columnar protruding portion <NUM> is of polyvinyl chloride. Also, the columnar protruding portion <NUM> is thermoplastic. Therefore, when the substrate <NUM> is strongly pushed toward the bottom plate portion 13a in a state in which the columnar protruding portion <NUM> is partially inserted into the through hole portion <NUM> of the substrate <NUM> on its tip side, a lower end portion <NUM> below the substrate <NUM> is plastically deformed. At this time, the columnar protruding portion <NUM> may be heated so as to be easily deformed. The heating is performed at a temperature of the degree that the material of the columnar protruding portion <NUM> is softened and other members are not deformed. The heating can be done with a hot plate.

The adjustment operator changes the inclination direction (including both the inclination angle and the direction of the slope) of the substrate <NUM> with respect to the reference plane. The change in the inclination direction can be realized by causing the adjustment operator to plastically deform the columnar protruding portion <NUM> through the use of a jig while pushing the through hole portion <NUM> toward the bottom plate portion 13a in a predetermined inclination direction. The predetermined inclination direction is the inclination direction in which the light spot Sp is moved in the direction of the arrow Ac on the display <NUM> of <FIG>.

In <FIG>, the columnar protruding portion <NUM> is divided into three parts of an upper end portion <NUM>, a fitting portion <NUM>, and a lower end portion <NUM>. The fitting portion <NUM> is positioned within the through hole portion <NUM> and fitted into the through hole portion <NUM>. The upper end portion <NUM> and the lower end portion <NUM> are located above and below the fitting portion <NUM>, respectively, and are exposed above and below the substrate <NUM>, respectively. The diameter of the lower end portion <NUM> is larger than that of the through hole portion <NUM>, and the diameter of the fitting portion <NUM> is equal to or smaller than the diameter of the through hole portion <NUM>. The diameter of the upper end portion <NUM> is equal to or smaller than the diameter of the through hole portion <NUM> and is smaller than the diameter of the through hole portion <NUM> at least at its upper end.

As the substrate <NUM> is pushed toward the bottom plate portion 13a in the through hole portion <NUM>, the columnar protruding portion <NUM> is plastically deformed at the fitting portion <NUM> and the lower end portion <NUM>. The inclination direction of the substrate <NUM> with respect to the reference plane is determined by the fitting angle between the through hole portion <NUM> and the fitting portion <NUM>.

<FIG> is a state diagram when the inclination direction of the substrate <NUM> with respect to the bottom plate portion 13a is completed in its adjustment. When the light spot Sp overlaps the target position <NUM> on the display <NUM>, the work of adjusting it is completed.

Since a direction β in which a normal line <NUM> of the substrate <NUM> inclines with respect to a normal line 13ah of the bottom plate portion 13a is opposite to a direction α in which the light beam Lp inclines with respect to the normal line <NUM> of the substrate <NUM>, the deviation of the light beam Lp is improved. Further, since the inclination angle of the light beam Lp with respect to the normal line <NUM> of the substrate <NUM> and the inclination angle of the normal line <NUM> of the substrate <NUM> with respect to the normal line 13ah of the bottom plate portion 13a are the same, the light beam Lp becomes perpendicular to the bottom plate portion 13a.

Further, the bottom plate portion 13a and the uprising plate portion 13b are integral members, and the plate-like mirror <NUM> and the rotary type mirror <NUM> fixed to the uprising plate portion 13b have a positional relationship with the bottom plate portion 13a, which does not change due to the inclination of the substrate <NUM>. That is, in the present invention, the positional relationship between the light beam Lp, the plate-like mirror <NUM>, and the rotary type mirror <NUM> is guaranteed with the bottom plate portion 13a as a reference.

Incidentally, although the inclination of the substrate <NUM> with respect to the bottom plate portion 13a when viewed from Y direction is illustrated in <FIG>, the substrate <NUM> is inclined with respect to the bottom plate portion 13a even when viewed from the X direction simultaneously.

After that, the substrate <NUM> and the columnar protruding portion <NUM> are fixed to each other by bonding, welding, or by expanding the diameter of the upper end portion <NUM> in a state in which the substrate <NUM> is unbalanced, i.e., inclined with respect to the bottom plate portion 13a. In the case of welding, the columnar protruding portion <NUM> needs to have heat fusibility. <FIG> shows a state in which the upper end portion <NUM> is expanded in diameter. The upper end portion <NUM> is plastically deformed to a diameter larger than the diameter of the through hole portion <NUM> by being crushed from above, and is fixed to the upper surface of the substrate <NUM>.

<FIG> is an explanatory view of the work of correcting the emission direction from the emission unit <NUM> of the VCSEL <NUM> in a manner different from that of <FIG>. In the case of <FIG>, contrary to the case in <FIG>, the columnar protruding portion <NUM> is made of a material which is relatively harder than the substrate <NUM>. For example, epoxy resin can be selected for the substrate <NUM>, and iron or brass can be selected for the columnar protruding portion <NUM>. Therefore, the substrate <NUM> is strongly pushed toward the bottom plate portion 13a in the direction of an arrow A2 in a state in which the columnar protruding portion <NUM> is partially inserted into the through hole portion <NUM> of the substrate <NUM> on its distal end side.

Thus, as shown within a range Ra in a lower diagram of <FIG>, the columnar protruding portion <NUM> retains the shape of the original cone or truncated cone, while the fitting portion <NUM> of the columnar protruding portion <NUM> is radially crushed by plastic deformation. As a result, the shape of the columnar protruding portion <NUM> and the shape of the fitting portion <NUM> become the same. Further, the upper end surface of the lower end portion <NUM> forms a plane protruding radially from the through hole portion <NUM> and supports the substrate <NUM>.

The inclination direction of the substrate <NUM> with respect to the reference plane is determined by the fitting angle between the through hole portion <NUM> and the fitting portion <NUM>. In subsequent processing, as in the case of <FIG>, the substrate <NUM> and the columnar protruding portion <NUM> are fixed to each other by adhesion, welding, or by enlarging the diameter of the upper end portion <NUM>.

The plate-like mirror <NUM> and the rotary type mirror <NUM> are assembled to the uprising plate portion 13b after adjusting the inclination direction of the substrate <NUM> with respect to the reference plane. The plate-like mirror <NUM> and the rotary type mirror <NUM> are optical elements which generate an optical path for causing the light beam Lp emitted from the VCSEL <NUM> to enter the rotating mirror <NUM> of the MEMS optical deflector <NUM>. Therefore, it is necessary to assemble both mirrors to the uprising plate portion 13b at a proper inclination angle so that a proper optical path is generated. <FIG> and <FIG> are explanatory views of the work of adjusting the inclination angle when assembling the plate-like mirror <NUM> and the rotary type mirror <NUM> to the uprising plate portion 13b, respectively.

The inclination angle of the plate-like mirror <NUM> is such that the plate-like mirror <NUM> is rotated in the direction of an arrow Ad within the inclined groove <NUM> so that the VCSEL <NUM> is turned on and the light beam Lp reflected by the plate-like mirror <NUM> generates a light spot Sp at a reference position of a predetermined screen <NUM>. When the light spot Sp as the irradiation position of the light beam Lp on the screen <NUM> reaches the reference position, the plate-like mirror <NUM> is fixed to the inclined groove <NUM> by adhesion or the like.

The assembly of the rotary type mirror <NUM> to the uprising plate portion 13b is performed after the assembly of the plate-like mirror <NUM> to the uprising plate mirror 13b. The inclination angle of the rotary type mirror <NUM> is such that the plate-like mirror <NUM> is rotated in the direction of an arrow Ae within the through hole <NUM> so that the VCSEL <NUM> is turned on and the light beam Lp reflected in the order of the plate-like mirror <NUM>, the rotary type mirror <NUM>, and the rotating mirror <NUM> of the MEMS optical deflector <NUM> generates a light spot Sp at a reference position of a predetermined screen <NUM>. When the light spot Sp as the irradiation position of the light beam Lp on the screen <NUM> reaches the reference position, the rotary type mirror <NUM> is fixed to the screen <NUM> by adhesion or the like.

<FIG> is a structural view of adjusting an inclination direction of a substrate <NUM> by one columnar protruding portion <NUM>. In <FIG>, the two columnar protruding portions <NUM> are provided, but in <FIG>, one of the two columnar protruding portions <NUM> (the columnar protruding portion <NUM> on the rear side in this example) is replaced by a bulging portion <NUM> at the same position. Accordingly, the substrate <NUM> has only one through hole portion <NUM>.

The bulging portion <NUM> is formed with a convex curved surface, e.g., a hemispherical surface. The amount of protrusion thereof from a bottom plate portion 13a is higher in the columnar protruding portion <NUM> than in the bulging portion <NUM>.

<FIG> shows a situation when adjusting the inclination direction of the substrate <NUM> with respect to the configuration of <FIG>. In the initial state of the substrate <NUM> before adjustment of the inclination direction, unlike <FIG>, the substrate <NUM> is not parallel to the bottom plate portion 13a but descends toward the rear end side at an inclination angle ya. Further, in the initial state, the direction of emission of a light beam Lp is inclined at a predetermined angle from the vertical direction with respect to the bottom plate portion 13a. Therefore, a light spot Sp is separated from a target position <NUM> on a display <NUM>.

The adjustment operator pushes the front end side of the substrate <NUM>, i.e., the side of the columnar protruding portion <NUM> downward. Consequently, the columnar protruding portion <NUM> is plastically deformed as described in <FIG>, and hence the inclination direction of the substrate <NUM> is adjusted to an appropriate value. That is, the light spot Sp overlaps the target position <NUM> on the display <NUM> of <FIG>.

Even when one columnar protruding portion <NUM> is provided, as in <FIG>, the through hole portion <NUM> side is plastically deformed to change a fitting angle between the through hole portion <NUM> and the columnar protruding portion <NUM>, so that a desired inclination direction can be obtained.

<FIG> and <FIG> are perspective views of support frame bodies <NUM> having a protrusion <NUM> and a bulging portion <NUM> each added to an upper surface of a bottom plate portion 13a. Description will be made about only differences from <FIG> already described. The protrusion <NUM> and the bulging portion <NUM> are both located on a center line Cn (<FIG>). The center line Cn is as defined in <FIG>. Further, the bulging portion <NUM> is located at the intersection of a line segment connecting the two columnar protruding portions <NUM> and the center line Cn in top view.

The heights of the protrusion <NUM> and the bulging portion <NUM> from the bottom plate portion 13a are lower than the height of the columnar protruding portion <NUM> in the initial state. The protrusion <NUM> and the bulging portion <NUM> are not plastically deformed. The two columnar protruding portions <NUM> are then plastically deformed by adjusting the inclination direction of the substrate <NUM> with respect to the bottom plate portion 13a. The heights of the two columnar protruding portions <NUM> after the plastic deformation are such that one columnar protruding portion <NUM> is higher in height than the protrusion <NUM> and the bulging portion <NUM>, and the other columnar protruding portion <NUM> is lower in height than the protrusion <NUM> and the bulging portion <NUM>. Consequently, the lower surface of the substrate <NUM> contacts the protrusion <NUM> or the bulging portion <NUM>. The protrusion <NUM> and the bulging portion <NUM> have a role of stabilizing the inclination direction of the substrate <NUM>.

<FIG> is a view showing a spectacles-type video display device <NUM> as an application example of the optical scanning device <NUM>. The spectacles-type video display device <NUM> will be briefly described. The spectacles-type video display device <NUM> includes a spectacle body <NUM> and a video generation device <NUM> detachably attached to the spectacle body <NUM> by a clip <NUM>. The spectacle body <NUM> includes left and right temples 161a and 161b and a front frame <NUM> coupled to front ends of the left and right temples 161a and 161b at both left and right ends. The front frame <NUM> further includes left and right lens frame portions 164a and 164b, and a bridge <NUM> connecting the left and right lens frame portions 164a and 164b.

The optical scanning device <NUM> is incorporated in one-row arrangement within the video generation device <NUM> together with other elements (for example: buffer amplifier for MEMS sensor and LDD (laser driver)) along the extension direction of the temple 161b of the spectacle body <NUM>. Incidentally, in this one-row arrangement, the optical scanning device <NUM> is arranged in the forefront, that is, closest to the lenses 167a and 167b. Thus, the light beam Lp (<FIG>) emitted from the optical scanning device <NUM> irradiates the inner surface side of the lens 167b to generate an image in a scanning area <NUM>.

The optical scanning device <NUM> includes a VCSEL <NUM>. The VCSEL <NUM> is an example of a surface emitting laser element. The present invention can adopt a laser light source other than a vertical cavity surface emitting laser (VCSEL) as long as it is of the surface emitting laser element.

The optical scanning device of the present invention can be applied not only as a video generation device for smart glasses, but also as a vide generation device for an ultra-compact projector and an interactive projector.

In the optical scanning device <NUM>, the fitting angle between the through hole portion <NUM> and the columnar protruding portion <NUM>, which defines the relative inclination angle between the substrate <NUM> and the bottom plate portion 13a is defined by mutual fitting by either one of the plastic deformation (<FIG>) of the upper portion of the columnar protruding portion <NUM> and the plastic deformation (<FIG>) of the through hole portion <NUM>. In the optical scanning device of the present invention, it is sufficient if mutual fitting by at least one plastic deformation is taken. That is, it does not exclude mutual fitting by both plastic deformations.

In the optical scanning device <NUM>, the bottom plate portion 13a as the bottom plate of the present invention is coupled to the uprising plate portion 13b as a part of the support frame body <NUM>. The bottom plate of the present invention may be a single component.

In the optical scanning device <NUM>, the plate-like mirror <NUM> and the rotary type mirror <NUM> serve as optical elements which generate an optical path for causing the light beam Lp emitted from the VCSEL <NUM> as a light source to enter the rotating mirror <NUM> of the MEMS optical deflector <NUM>. The optical element of the present invention may be a prism or the like other than a mirror.

In the optical scanning device <NUM>, the columnar protruding portion <NUM> has an upper end portion <NUM> and a fitting portion <NUM> (<FIG> and <FIG>) as upper portions with respect to its lower end coupled to the bottom plate portion 13a. The columnar protruding portion of the present invention only needs to have the fitting portion <NUM> as the upper portion, and the portion above the substrate (for example: the upper end portion <NUM>) may be omitted. Incidentally, in the absence of the upper end portion <NUM>, it is difficult to mutually fix the bottom plate portion 13a and the substrate <NUM> by the enlarged diameter portion (e.g., the upper end portion <NUM> in <FIG>) or by welding, but mutual fixing by adhesion is possible.

In the optical scanning device <NUM>, the center line Cn extends in the longitudinal direction of the substrate <NUM>. The center line Cn may be inclined with respect to the longitudinal direction.

In the optical scanning device <NUM>, the VCSEL <NUM> is smaller than the MEMS optical deflector <NUM> in size in the lateral direction. Then, the arrangement direction as a line segment connecting the emission unit <NUM> as the center of the VCSEL <NUM> and the center of the MEMS optical deflector <NUM> extends in the longitudinal direction of the substrate <NUM>. Therefore, when two through hole portions <NUM> are provided, they are fixed to the bottom plate in a positional relationship in which when viewed from the top of the substrate <NUM>, they are arranged on one side and the other side in the longitudinal direction respectively with respect to a mounting area including the VCSEL <NUM> and the MEMS optical deflector <NUM> in the substrate <NUM>, and are arranged on one side and the other side in the lateral direction respectively with respect to the VCSEL <NUM>. This is because the fitting angle between the through hole portion <NUM> and the columnar protruding portion <NUM> at such a position stabilizes the regulation of the relative inclination angle between the substrate <NUM> and the bottom plate portion 13a.

The optical scanning device <NUM> has one or two columnar protruding portions <NUM>. The optical scanning device of the present invention may have three or more columnar protruding portions <NUM>.

Claim 1:
An optical scanning device (<NUM>), comprising:
a substrate (<NUM>) having at least one through hole portion (<NUM>);
a light source and a MEMS optical deflector (<NUM>, <NUM>) mounted on the substrate;
an optical element generating an optical path which causes a light beam emitted from the light source to enter the MEMS optical deflector;
a bottom plate arranged below the substrate; and
a columnar protruding portion (<NUM>, <NUM>) having a lower end larger in size than a through hole (<NUM>) of the through hole portion and fixed to an upper surface of the bottom plate in a shape tapered toward a tip of the columnar protruding portion, and having an upper portion fitted into the through hole portion,
wherein at least one of the upper portion of the columnar protruding portion and the through hole portion is plastically deformed so that the two are fitted to each other, and
wherein a relative inclination angle between the substrate and the bottom plate is defined by a fitting angle between the through hole portion and the columnar protruding portion.