JP6627994B2 - Optical deflector, optical scanning device, image forming device, and vehicle - Google Patents

Description

The present invention relates to an optical deflector, the optical scanning apparatus, relates to an image forming apparatus and a vehicle, and more particularly, an optical deflector for deflecting the light, an optical scanning device Ru comprising a light deflector, an image comprising the optical scanning device The present invention relates to a forming apparatus and a vehicle including the image forming apparatus.

  2. Description of the Related Art Conventionally, an optical scanner package that scans a surface to be scanned with light from a light source is known (for example, see Patent Document 1).

  The optical scanner package includes a light transmitting window member disposed on an optical path of light from a light source, and a swingable mirror that reflects light transmitted through the light transmitting window member toward the light transmitting window member. And an optical deflector for deflecting light from the light source toward the surface to be scanned.

  However, in the optical scanner package disclosed in Patent Literature 1, an abnormal image may be generated on the surface to be scanned due to the influence of light reflected from the surface of the light transmitting window member of the light from the light source, or the surface to be scanned may be reduced. There was a risk that scanning could not be performed stably.

The present invention relates to a container having an opening through which light passes, and a mirror accommodated in the container and deflecting light incident through the opening by rotating around a predetermined rotation axis from a reference plane. A light transmissive plate attached to the opening and inclined about the rotation axis with respect to the reference plane, wherein the mirror is rotatable about a first axis and The mirror is rotatable about a second axis orthogonal to the first axis, and the frequency of rotation about the first axis is higher than the frequency of rotation about the second axis . The maximum deflection angle around the second axis is smaller than the inclination angle of the light transmitting plate with respect to the reference plane, and the maximum deflection angle around the first axis is larger than the maximum deflection angle around the second axis. And the light transmitting plate is arranged around the second axis with respect to the reference plane. An optical deflector that obliquely.

  ADVANTAGE OF THE INVENTION According to this invention, generation | occurrence | production of an abnormal image on a to-be-scanned surface can be prevented, and a to-be-scanned surface can be scanned stably.

FIG. 1 is a diagram schematically illustrating a configuration of a projector device according to an embodiment. FIG. 2 is a diagram for describing a configuration and an operation of the optical deflector of FIG. 1. FIG. 3 is a diagram for explaining a configuration of an optical deflector. FIG. 9 is a diagram for explaining a projector device of a comparative example. FIG. 9 is a diagram schematically illustrating a configuration of a projector device of Modification Example 1. FIG. 14 is a diagram schematically illustrating a configuration of a projector device of Modification Example 2. FIG. 14 is a diagram schematically illustrating a configuration of a projector device of Modification Example 3. FIG. 14 is a diagram schematically illustrating a configuration of a projector device of Modification Example 4. FIG. 14 is a diagram schematically illustrating a configuration of a projector device of Modification Example 5. FIG. 14 is a diagram schematically illustrating a configuration of a projector device of Modification Example 6. FIG. 19 is a drawing schematically showing a configuration of an optical deflector of Modification 7. It is a figure showing roughly an example of a head up display device.

  An embodiment of the present invention will be described below with reference to FIGS. FIG. 1 schematically shows a projector device 100 as an image forming apparatus according to one embodiment.

  The projector device 100 is used, for example, in a state where it is mounted on a floor or an installation table of a building, in a state where it is hung from a ceiling of a building, or in a state where it is hung on a wall of a building. In the following, description will be given using an XYZ three-dimensional orthogonal coordinate system in which the vertical direction shown in FIG.

  The projector device 100 includes, for example, an optical scanning device 5, a control device 7, and the like as shown in FIG.

  The optical scanning device 5 includes an LD 10 (laser diode) as a light source, an optical deflector 20, and a light blocking member 30.

  The LD 10 emits a laser beam in the + X direction. Hereinafter, the laser light emitted from the LD 10 is also referred to as “emitted light”.

  The optical deflector 20 has a housing including a package 20a and a cover glass 20b, and a mirror 20c housed in the housing. Here, as an example, the XZ cross-sectional shape of the container is substantially trapezoidal.

  The package 20a is a box-shaped member with no lid, and is arranged such that the opening is located on the optical path of the emitted light (to face the −X side). As a material of the package 20a, for example, ceramic, resin, aluminum, or the like is used. Here, as an example, the package 20a is formed of a member having a substantially J-shaped XZ cross section, and is provided with a wiring member (not shown) for supplying power to a driving unit described later.

  The cover glass 20b is made of a transparent or translucent glass plate, and is joined to the opening end of the package 20a so as to cover the opening of the package 20a. That is, the cover glass 20b is disposed on the optical path of the emitted light, and functions as a light transmission window member. Here, as an example, the cover glass 20b is arranged parallel to the Y axis.

  The mirror 20c is a so-called MEMS mirror, and is arranged around a first axis and a second axis orthogonal to each other in the package 20a so that the reflection surface is located on the optical path of the emitted light transmitted through the cover glass 20b. It is swingably supported independently. Here, the first axis extends in a direction parallel to the XZ plane and inclined by a predetermined angle θ with respect to the XY plane. The second axis is parallel to the Y axis. The mirror 20c is shielded from outside air by being accommodated in the container, and is protected from dust and moisture.

  More specifically, as shown in FIG. 2, the mirror 20c is supported by a first frame member via a torsion bar so as to be swingable around a first axis inside the first frame member. Is supported by the second frame member via a torsion bar so as to be swingable around the second axis inside the second frame member. Then, the mirror 20c is independently driven within a first swing range around the first axis and within a second swing range around the second axis by a driving unit (actuator) (not shown). ing. The second frame member is supported by the package 20a. Here, the first swing range (first angle range) is set to be larger than the second swing range (second angle range). As the driving unit, for example, an electromagnetic system, a piezoelectric system, or the like is used. Note that the above-described configuration in which the mirror 20c swings independently around the first axis and the second axis is merely an example, and can be appropriately changed. In FIG. 2, the illustration of the container is omitted.

  The light blocking member 30 will be described later.

  The optical deflector 20 is manufactured by performing a series of steps of mounting the mirror 20c on the package 20a (MEMS process) and joining the cover glass 20b to the package 20a (sealing step). .

  In the optical scanning device 5 configured as described above, the laser light from the LD 10 is incident on the surface (the −X side surface) of the cover glass 20b, and the light transmitted through the cover glass 20b is incident on the reflection surface of the mirror 20c. Incident. The laser light incident on the reflection surface of the mirror 20c is reflected (toward the cover glass 20b) in a direction corresponding to the positions around the first axis and the second axis of the mirror 20c, and is reflected on the back surface (+ X side) of the cover glass 20b. Surface). Of the laser light incident on the back surface of the cover glass 20b, the laser light transmitted through the cover glass 20b is guided to the surface to be scanned (the surface of the screen S).

  At this time, for example, by vibrating the mirror 20c around the first axis at a high frequency while vibrating around the second axis at a low frequency, it is possible to two-dimensionally scan a predetermined scanning area on the surface to be scanned (FIG. 2). In other words, the scanning area is reciprocally scanned at a high speed in the main scanning direction, which is a scanning direction corresponding to the first axis, while being one-way scanned at a low speed in the sub-scanning direction, a scanning direction corresponding to the second axis. Raster scan can be performed.

  Here, the scanning region has a main scanning direction (Y-axis direction), which is a scanning direction corresponding to around the first axis, as a longitudinal direction, and a sub-scanning direction (Z-axis direction), which is a scanning direction corresponding to around the second axis. Is a substantially rectangular shape having a short side direction.

  Returning to FIG. 1, the control device 7 includes an image processing unit 7a, an LD control unit 7b, and a mirror control unit 7c.

  The image processing unit 7a performs predetermined processing (for example, distortion correction processing, image size change processing, resolution conversion processing, etc.) on image information from a higher-level device such as a personal computer, and sends the processed information to the LD control unit 7b.

  The LD controller 7b modulates the intensity of the drive signal (pulse signal) based on the image information from the image processor and outputs the modulated signal to the LD. Further, the LD control unit 7b determines the light emission timing of the LD 10 (the timing at which a drive signal is supplied to the LD 10) based on a synchronization signal described later from the mirror control unit 7c.

  The mirror controller 7c synchronizes the deflection angle of the mirror 20c with the light emission timing of the LD 10 based on a detection signal from a sensor (not shown) that detects position information about the first axis and the second axis of the mirror 20c. Is output to the LD control section 7b.

  In the projector device 100 configured as described above, laser light modulated based on image information is emitted from the LD 10 and deflected by the optical deflector 20 toward the surface to be scanned. As a result, a predetermined scanning area on the surface to be scanned is two-dimensionally scanned in the main scanning direction and the sub-scanning direction, and a desired image is formed in the scanning area.

  By the way, in particular, a semiconductor laser (laser diode) is suitable for a light source of a scanning type projector device as in the present embodiment because a high directivity of emitted light can provide high light use efficiency.

  However, when the emitted light is incident on the surface of the cover glass 20b, a part of the light is transmitted through the cover glass 20b, and the remaining part (for example, less than several%) is reflected by the surface of the cover glass 20b and becomes stray light.

  In this case, if the reflected light of the emitted light on the surface of the cover glass 20b (hereinafter, also referred to as surface reflected light) enters the scanning area, an abnormal image is generated in the image formed in the scanning area, Image quality is degraded (see FIG. 4).

  That is, the stray light generated by the laser light from the LD 10 has high intensity due to its directivity and is easily recognized. If unstrayed stray light (stationary beam) is generated with respect to the laser beam (dynamic beam) deflected by the optical deflector 20, even a small amount of the stray light (relative beam) becomes relatively bright, so that it is visually recognized, and the image quality deteriorates. Would.

  Therefore, in the present embodiment, the positional relationship between the cover glass 20b and the mirror 20c is set such that the optical path of the surface reflected light deviates from the scanning area. Here, the positional relationship between the cover glass 20b and the mirror 20c is set such that the optical path of the surface reflected light deviates from the scanning area in the sub-scanning direction (Z-axis direction).

  More specifically, the positional relationship between the cover glass 20b and the mirror 20c is such that the mirror 20c is located at an arbitrary position within a first swing range around the first axis, and the second swing around the second axis. When positioned at an arbitrary position within the range, the reflection surface of the mirror 20c and the surface of the cover glass 20b are set so as to be non-parallel. In this case, regardless of the positions of the mirror 20c about the first axis and the second axis, the reflection surface of the mirror 20c and the surface of the cover glass 20b do not become parallel, and it is possible to prevent the surface reflected light from entering the scanning area. Can be prevented.

  Specifically, as can be seen from FIG. 3, the maximum deflection angle α (the acute angle) from the reference plane (the center of vibration) around the second axis of the mirror 20c is determined by the plane parallel to the surface of the cover glass 20b and the reference plane. (A sharp angle), ie, the inclination angle of the cover glass 20b with respect to the reference plane. Here, the reference plane is a plane including the first axis and the second axis.

  As can be seen from FIG. 1, the positional relationship between the cover glass 20 b and the mirror 20 c is such that the optical path of the laser light (emission light) from the LD 10 and the optical path of the surface reflected light are deflected by the optical deflector 20. It is set to be on the same side as viewed from the −Y direction with respect to the optical path of (scanning light). That is, the optical path of the emitted light and the optical path of the surface reflected light are on the opposite side to the optical path of the scanning light with respect to a predetermined virtual plane parallel to the Y axis.

  In this case, since the incident angle of the emitted light on the cover glass 20b can be reduced, the transmittance of the emitted light to the cover glass 20b can be increased. As a result, light use efficiency can be improved.

  As can be seen from FIG. 1, the positional relationship between the cover glass 20b and the mirror 20c is such that the optical path of the emitted light and the optical path of the scanning light are on the same side as the optical path of the surface reflected light when viewed from the −Y direction. Is set to That is, the optical path of the emitted light and the optical path of the scanning light are on the opposite side to the optical path of the surface reflected light with respect to a predetermined virtual plane parallel to the Y axis.

  In this case, the optical path of the surface reflected light can be sufficiently separated from the scanning area. If the optical path of the surface reflected light is close to the scanning area, the surface reflected light may be scattered by other members in the apparatus near the scanning area, and may enter the scanning area with relatively high intensity.

  Here, if the surface reflected light returns to the LD 10, the laser oscillation of the LD 10 becomes unstable, and the output fluctuates. As a result, the surface to be scanned cannot be stably scanned.

  Therefore, in the present embodiment, the incident angle of the emitted light on the cover glass 20b is set to a value other than 0 °, and the surface reflected light is prevented from directly returning to the LD 10.

  However, if the optical path of the surface reflected light is not sufficiently separated from the optical path of the emitted light, the surface reflected light may be scattered by other members in the device, and the scattered light may enter the LD 10 with a relatively high intensity.

  Therefore, in the present embodiment, as shown in FIG. 1, the light blocking member 30 is disposed on the optical path of the surface reflected light. The light-blocking member 30 is arranged in such a manner as to reflect the incident surface reflected light in a direction away from the optical path of the emitted light.

  It is preferable that the light incident surface (the surface on which the surface reflected light is incident) of the light shielding member 30 is a surface that diffuses and reflects light (for example, a rough surface). Further, the light shielding member 30 may have a function of absorbing at least a part of the surface reflected light, or may have a function of transmitting a part of the surface reflected light. When the light shielding member 30 has a function of absorbing most of the surface reflected light, the posture of the light shielding member 30 may be arbitrary.

  The optical scanning device 5 according to the embodiment described above includes the LD 10, the cover glass 20b disposed on the optical path of the laser light (emission light) from the LD 10, and the cover glass 20b that transmits the laser light transmitted through the cover glass 20b. An optical deflector 20 for deflecting the laser light from the LD 10 toward the surface to be scanned, and a cover glass 20b for the laser light from the LD 10. A light shielding member 30 disposed on an optical path of light reflected on the surface (surface reflected light).

  In this case, since the surface reflected light is shielded by the light blocking member 30, it is possible to prevent the surface reflected light from being incident on the scanning area on the surface to be scanned, and to prevent the surface reflected light from returning to the LD.

  As a result, an abnormal image can be prevented from being generated on the surface to be scanned, and the surface to be scanned can be stably scanned.

  More specifically, the mirror 20c is swingable within a first swing range around the first axis and within a second swing range around the second axis, and the mirror 20c is moved in the first swing range. When located at an arbitrary position within the range and at an arbitrary position within the second swing range, the reflection surface of the mirror 20c and the surface of the cover glass 20b are non-parallel.

  On the other hand, in the optical scanning device of the comparative example shown in FIG. 4, the light deflector has a so-called flat package, and the surface of the cover glass is positioned with respect to the reflection surface of the mirror located at a predetermined position within the swing range. Be parallel.

  In this case, the surface reflected light enters the central portion of the scanning area and is recognized as a bright point at the central portion of the image (an abnormal image is generated). Therefore, it is conceivable to make the distance of the cover glass to the mirror sufficiently long so as to separate the optical path of the surface reflected light from the scanning light, but this will increase the size of the package and increase the cost. Also, even if the cover glass is slightly tilted with respect to the mirror, that is, an angle smaller than the maximum deflection angle of the reflection surface, the surface reflected light enters the periphery of the scanning area, and a bright spot at the periphery of the image is obtained. Is recognized (an abnormal image is generated).

  By the way, in order to increase the inclination angle of the cover glass 20b with respect to the reference plane (the plane including the first axis and the second axis), the height dimension of the package 20a (the two parallel sides of the package 20a in the XZ section). It is necessary to increase the length of the longer side portion), which makes processing of the package 20a difficult, and as a result, the size and cost of the optical deflector 20 are increased.

  Therefore, in the optical deflector 20, the mirror 20c uses the sub-scan corresponding to the optical path of the surface reflected light around the second axis (around the axis having the smaller swing range) among the first axis and the second axis. It is out of the scanning area in the direction (Z-axis direction).

  In this case, the cover glass is compared with a case where the optical path of the surface reflected light is out of the scanning area in the main scanning direction (Y-axis direction) corresponding to the first axis (around the axis having the larger swing range). It is possible to reduce the angle of inclination of the optical deflector 20b with respect to the reference plane, and to suppress an increase in the size and cost of the optical deflector.

  Note that, as in the projector device 200 of the first modification shown in FIG. 5, the positional relationship between the cover glass 22b and the mirror 20c is such that the optical path of the emitted light and the optical path of the scanning light are in a predetermined virtual plane parallel to the Y axis. May be set to be on a different side from the optical path of the surface reflected light (as viewed from the −Y side), that is, to sandwich the optical path of the surface reflected light as viewed from the −Y side.

  Also in the first modification, since the surface reflected light is shielded by the light blocking member 30, the surface reflected light can be prevented from entering the scanning area, and the surface reflected light can be prevented from returning to the LD. Further, in the first modification, since the angle difference between the optical path of the surface reflected light and the optical path of the scanning light viewed from the −Y direction can be reduced as compared with the above embodiment, the inclination angle of the cover glass 20b can be reduced, and The size and cost of the deflector can be reduced.

  Also, like the projector devices 300 and 400 of Modification 2 and Modification 3 shown in FIGS. 6 and 7, respectively, a lens 60 is provided on the optical path between the LD 10 and the optical deflectors 20 and 22. May be. Here, as an example, a coupling lens that collimates, weakly diverges, or weakly converges the emitted light is used as the lens 60. Note that the lens 60 may be a lens other than the coupling lens.

  In the second and third modifications, the light blocking member 30 is disposed between the lens 60 and the optical deflectors 20 and 22. As a result, it is possible to prevent the surface reflected light from returning to the LD 10 via the lens 60.

  Also, like the projector devices 500 and 600 of Modifications 4 and 5 shown in FIGS. 8 and 9, respectively, a lens 60 disposed on the optical path between the LD 10 and the optical deflectors 20 and 22; An opening member 80 may be provided on the optical path between the lens 60 and the optical deflectors 20 and 22. Note that the projector devices 500 and 600 do not include the light blocking member 30.

  The opening member 80 has an opening through which a part of the light emitted through the lens 60 passes, and shapes the emitted light. Further, the opening member 80 is positioned on the optical path of the reflected light (surface reflected light) of the laser light having passed through the opening at the surface of the cover glasses 20b and 22b. That is, the opening member 80 has a light blocking portion for blocking the surface reflected light.

  In the projector devices 500 and 600 of Modifications 4 and 5, the aperture member 80 has both the function of shaping the emitted light and the function of blocking the surface reflected light, so that the configuration is simplified and the cost is reduced. be able to.

  The portion of the aperture member 80 on which the surface reflected light is incident may be angled so that the surface reflected light does not go to the optical deflector, or may be roughened and sufficiently scattered. Alternatively, it may be formed of a material that absorbs at least a part of the surface reflected light.

  Further, as in the projector device 700 of Modification 6 shown in FIG. 10, the cover glass 24b may be arranged in parallel to the reference plane (a plane including the first axis and the second axis).

  In Modification 6, the package 24a of the optical deflector 24 is a flat package formed of a member having a substantially U-shaped XZ cross section, and the surface reflected light is directed toward the optical path of the scanning light as in the comparative example shown in FIG. Progress.

  Therefore, in the sixth modification, the light blocking member 30 is disposed on the optical path (on the path) of the surface reflected light and at a position deviated from the optical path of the scanning light. As a result, surface reflected light can be shielded. It is preferable that the posture of the light shielding member 30 is adjusted so that the light reflected (scattered) by the light shielding member 30 does not go to the LD 10 and the optical deflector 24.

  According to the sixth modification, a small-sized flat package that is easy to process can be used for the optical deflector 24, so that the size and cost can be reduced.

  Further, like the optical deflector 26 of the modification 7 shown in FIG. 11, a package 26a (first holding unit) holding the mirror 20c and a holding member 26c (second holding unit) holding the cover glass 26b. ) May be joined.

  By employing such a configuration, a flat package can be used as the package 26a, and the cover glass 26b can be arranged to be inclined with respect to the reference plane.

  According to the seventh modification, the processing of the package can be facilitated, and the same effect as the above embodiment can be obtained.

  Further, in the above embodiment and each of the modifications, the optical deflector is used in the projector device as the image forming device. However, the present invention is not limited to this. For example, the head-up display device 1000 as the image forming device shown in FIG. May be used. The head-up display 1000 is mounted on, for example, a vehicle, an aircraft, a ship, and the like.

  More specifically, as shown in FIG. 12 as an example, a head-up display 1000 includes a plurality of two-dimensionally arranged microlenses arranged on an optical path of laser light (scanning light) deflected by an optical deflector. And a translucent member (for example, a combiner) arranged on the optical path of the laser beam through the microlens array. In this case, the surface (scanned surface) of the microlens array is two-dimensionally scanned by the laser light in accordance with the operation of deflecting the laser light around the first axis and the second axis by the optical deflector, and an image is formed on the scanned surface. It is formed. Then, the image light passing through the microlens array enters the translucent member, and a virtual image of the image light is formed. That is, the observer can visually recognize the virtual image of the image light via the translucent member. At this time, since the image light is diffused by the microlens array, so-called speckle noise can be reduced.

  It should be noted that a light transmitting member (for example, a transmission screen) other than the micro lens array may be used instead of the micro lens array. Further, for example, a mirror such as a concave mirror or a plane mirror may be provided on an optical path between a light transmitting member such as a microlens array and a transmissive screen and a translucent member. Further, the translucent member may be replaced with a light transmitting window (for example, window glass) of a vehicle, an aircraft, a ship, or the like.

  Therefore, a vehicle (eg, a window glass) including a head-up display 1000 and a light transmission window (for example, a window glass) disposed on an optical path of light deflected by an optical deflector of the head-up display 1000 and transmitted through the light transmission member. For example, a car, a train, etc.) can be provided. In this case, the image light transmitted through the light transmitting member enters the light transmitting window, and a virtual image of the image light is formed. That is, the observer can visually recognize the virtual image of the image light through the light transmission window.

  Further, the present invention provides an image forming apparatus having the same configuration as the head-up display apparatus 1000 for visually recognizing a virtual image such as a head mounted display apparatus, a prompter (document display apparatus), and a vehicle provided with the image forming apparatus. You can also.

  Further, the optical scanning device provided with the optical deflectors of the above-described embodiment and each modified example can be employed in an image forming apparatus such as a printer, a copying machine, and an optical plotter, and can also provide the image forming apparatus.

  In the above-described embodiment and each modification, the positional relationship between the cover glass and the mirror is such that the optical path of the emitted light and the optical path of the surface reflected light are on the same side with respect to the optical path of the scanning light when viewed from the −Y direction. Although set, it may be set to be on a different side (opposite side).

  Further, in the above-described embodiment and each of the modifications, the positional relationship between the cover glass and the mirror is set such that the optical path of the surface reflected light deviates from the scanning region in the sub-scanning direction, but is not limited thereto. For example, the optical path of the surface reflected light may deviate from the scanning area in the main scanning direction, or may deviate from the scanning area in both the sub-scanning direction and the main scanning direction. In order to make the optical path of the surface reflected light deviate from the scanning area in the main scanning direction, the maximum deflection angle (acute angle) from the reference plane (the center of vibration) around the first axis of the mirror is set to the surface of the cover glass. May be set to be smaller than the angle (acute angle) between the angle and the plane parallel to the reference plane.

  In this case, the positional relationship between the cover glass and the mirror may be set so that the optical path of the emitted light and the optical path of the surface reflected light are on the same side with respect to the optical path of the scanning light when viewed from the + Z direction. (Opposite side). The positional relationship between the cover glass and the mirror may be set so that the optical path of the emitted light and the optical path of the surface reflected light are on the same side with respect to the optical path of the scanning light when viewed from the + Z direction. On the other side). In this case, when viewed from the + Z direction, the optical path of the emitted light and the optical path of the scanning light may be set to be on the same side with respect to the optical path of the surface reflected light, or may be on different sides (opposite side). May be set.

  Further, in the above-described embodiment and each of the modifications, the cover glass is used as the light transmitting window member. However, the present invention is not limited to this, and any member may be used as long as it is a light transmitting member.

  Further, in the above-described embodiment and each of the modifications, the shape, size, number, posture, and arrangement of the light shielding portions can be appropriately changed.

  Further, in the above-described embodiments and the respective modifications, an LD (laser diode), that is, an edge emitting laser is used as a light source of the optical scanning device. However, the present invention is not limited to this. May be used.

  In the above-described embodiment and each of the modifications, the control device has the image processing unit, but need not necessarily have the image processing unit.

  Further, in the above-described embodiment and each of the modifications, the LD control unit directly modulates the LD 10 based on the image information. However, instead of this, for example, a laser beam emitted from the LD 10 may be modulated based on the image information. A light modulation unit for performing modulation may be provided. That is, an external modulation method may be adopted.

  In the above-described embodiment and each modification, one optical deflector for two-dimensional scanning in two scanning directions (main scanning direction and sub-scanning direction) orthogonal to each other is adopted. For example, an optical deflector for performing one-dimensional scanning in one scanning direction, that is, an optical deflector including a mirror that swings only around one axis may be employed. Alternatively, two-dimensional scanning may be performed in two scanning directions orthogonal to each other by combining two optical deflectors each including a mirror that swings only around one axis. Even in such an optical deflector including a mirror that swings only around one axis, by adopting the same configuration as that of the above-described embodiment and each modified example, it is possible to prevent an abnormal image from being generated on the surface to be scanned. Thus, the scanning surface can be stably scanned.

  5: Optical scanning device, 10: LD (light source), 20: Optical deflector, 20b, 22b, 24b, 26b: Cover glass (light transmitting window member), 20c: Mirror, 26a: Package (first holding unit) , 26c: holding member (second holding portion), 30: light shielding member (light shielding portion), 60: lens, 80: opening member, 100, 200, 300, 400, 500, 600, 700: projector device (image forming) Device), 1000: Head-up display device (image forming device).

JP 2006-221171 A

Claims (6)

A container having an opening through which light passes,
A mirror that is housed in the housing body and deflects light incident through the opening by rotating about a predetermined rotation axis from a reference plane;
A light deflector attached to the opening, and a light transmitting plate inclined around the rotation axis with respect to the reference plane,
The mirror is rotatable about a first axis and is also rotatable about a second axis orthogonal to the first axis, and a frequency of rotation about the first axis is about the second axis. Higher than the frequency of rotation, the maximum deflection angle of the mirror about the second axis from the reference surface is smaller than the inclination angle of the light transmitting plate with respect to the reference surface, and the maximum deflection angle about the first axis. The angle is greater than the maximum deflection angle about the second axis;
The light deflector, wherein the light transmission plate is inclined around the second axis with respect to the reference plane. The container has a first member having a first opening having an opening surface parallel to the reference surface, and a second member attached to the first opening and having an opening surface inclined with respect to the reference surface. A second member having an opening;
The optical deflector according to claim 1 , wherein the light transmitting plate is attached to the second opening so as to be inclined around the rotation axis with respect to the reference plane. A light source, and an optical deflector according to claim 1 or 2 , which deflects light from the light source, an optical scanning device that scans a scanning region with light deflected by the optical deflector,
An optical scanning device, wherein an optical path of surface reflected light due to reflection of light from the light source on a surface of a light transmitting plate of the optical deflector is set out of the scanning area. An optical scanning device according to claim 3 ,
An image forming apparatus, comprising: an intensity modulator that modulates the intensity of a light source of the optical scanning device based on image information or a modulator that modulates light emitted from the light source based on image information. The image forming apparatus according to claim 4 , further comprising a light transmitting member that is scanned by light deflected by an optical deflector of the optical scanning device. An image forming apparatus according to claim 5 ,
A light transmission window disposed on an optical path of light deflected by a light deflector of the image forming apparatus and transmitted through the light transmission member.

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