JP2017016018A - Optical deflector, optical scanner, image formation device, image projection device, head-up display device and rader device - Google Patents

Abstract

Damage to a root portion of a driving beam is prevented. A fixed base 40, a mirror part 10 that reflects light, a pair of torsion bar springs 20a and 20b that support the mirror part 10, and a pair of torsion bar springs 20a and 20b correspond one-to-one, Are connected to the torsion bar springs 20a and 20b, the other end is connected to the fixed base 40, and a pair of drive beams 30a and 30b to which a piezoelectric member is fixed are provided. The mirror unit 10 and the torsion bar springs 20a and 20b are supported by the fixed base 40 in a cantilever manner to rotate and vibrate the mirror unit 10, and the fixed base 40 is connected to the root portion to which the drive beams 30a and 30b are connected. The driving beams 30a and 30b protrude in a direction narrower than the width of the driving beams 30a and 30b in a direction toward one end of the driving beams 30a and 30b. Protrusions 43a for supporting has 43b. [Selection] Figure 3

Description

  The present invention relates to an optical deflector, an optical scanning device, an image forming device, an image projection device, a head-up display device, and a radar device.

  An optical deflector that deflects and scans a light beam such as a laser beam is widely used in an image forming apparatus such as a copying machine, an image projection apparatus, a head display apparatus, a radar apparatus, and the like. Conventionally, as this type of optical deflector, there are those using electrostatic force, those using electromagnetic force, and those using piezoelectric power.

  The optical deflector using electrostatic force has parallel plate type and comb-shaped electrodes, and the comb-shaped electrodes can generate relatively large force due to the recent improvement of microfabrication technology, Since a sufficient light deflection angle cannot be obtained, the drive voltage must be increased to compensate. However, when the drive voltage is increased, the power supply system parts are increased, resulting in an increase in size as a whole and an increase in cost.

  Since an optical deflector using electromagnetic force needs to have a permanent magnet disposed outside, the structure of the device becomes complicated, the productivity is deteriorated, and miniaturization is difficult. The use of a magnetostrictive film or the like has been studied, but sufficient characteristics cannot be obtained because the characteristics as a magnetic material are inferior. Further, if a current is passed through the coil, excessive heat is likely to be generated, resulting in an increase in power consumption.

  On the other hand, when piezoelectric power is used, a relatively large driving voltage is required, but a large force can be generated with a small power. Although the piezoelectric device has a large generated force but has a small deformation amount, in order to expand the piezoelectric device, the piezoelectric member is bonded to another beam-like elastic member to form a unimorph structure or a bimorph structure. Thereby, it is also possible to obtain a large deformation by changing a slight distortion in the in-plane direction due to the piezoelectric power into a warp.

  Here, for example, an optical deflector that is small in size, has good driving efficiency, and can obtain a large angular amplitude is disclosed (see Patent Document 1). In this optical deflector, a large torsional deformation is generated in the elastic support member by a minute bending vibration of the driving beam, so that the mirror can efficiently rotate and a large rotation amplitude can be obtained.

  However, in the optical deflector described above, if the diameter of the mirror that deflects light is increased, the amplitude angle of the mirror is increased, or the resonance frequency is increased, the load on the drive beam is increased. There is a problem that it becomes large and easily breaks at the root of the drive beam.

  The present invention has been made in view of the above, and an optical deflector, an optical scanning device, and an image forming apparatus that prevent stress generated at the root portion of the driving beam by dispersing stress generated at the root portion of the driving beam. An object is to obtain an image projection device, a head-up display device, and a radar device.

  In order to solve the above-described problems and achieve the object, an optical deflector according to the present invention includes a fixed base, a mirror portion having a reflecting surface that reflects light, and a pair of elastic support members that support the mirror portion. A pair of drive beams, one-to-one corresponding to the pair of elastic support members, one end connected to the elastic support member, the other end connected to the fixed base, and a piezoelectric member fixed thereto; The drive beam is configured such that the mirror portion and the elastic support member are cantilevered by the fixed base to rotate and vibrate the mirror portion, and the drive beam is connected to the fixed base. The root portion has a protrusion that projects in a direction narrower than the width of the drive beam in a direction toward the one end of the drive beam and supports the drive beam.

  According to the present invention, there is an effect that the stress generated at the root portion of the drive beam can be dispersed to prevent the breakage occurring at the root portion of the drive beam.

FIG. 1 is a top view showing the entire optical deflector according to the first embodiment. FIG. 2 is a side view seen from the AA cross section in FIG. FIG. 3 is a back view seen from the arrow B in FIG. FIG. 4 is a diagram showing a wiring pattern in the vicinity of the root portion connected to the fixed base in the drive beam. FIG. 5 is a cross-sectional view taken along the line CC in FIG. FIG. 6 is a cross-sectional view taken along the line DD in FIG. FIG. 7 is a diagram illustrating the relationship between the protrusion amount of the protrusion and the stress of the root portion of the drive beam. FIG. 8 is a diagram showing another shape of the protrusion. FIG. 9 is a diagram showing another shape of the driving beam. FIG. 10 is a diagram showing another shape of the driving beam. FIG. 11 is a top view showing the entire optical deflector according to the second embodiment. FIG. 12 is a side view seen from the EE cross section in FIG. FIG. 13 is a back view seen from the arrow F in FIG. FIG. 14 is a back view seen from the arrow F in FIG. FIG. 15 is an overall configuration diagram of the optical scanning device according to the third embodiment. FIG. 16 is a diagram showing the connection between the optical deflector and the driving means used in the optical scanning device of FIG. FIG. 17 is an overall configuration diagram of the image forming apparatus. FIG. 18 is an overall configuration diagram of an image projection apparatus according to the fourth embodiment. FIG. 19 is a configuration diagram of an image projection apparatus according to the fourth embodiment. FIG. 20 is an overall conceptual diagram of the head-up display device of the fifth embodiment. FIG. 21 is a diagram illustrating a case where an image irradiated on the windshield is recognized as a virtual image. FIG. 22 is a diagram illustrating details of the image forming unit according to the fifth embodiment. FIG. 23 is an overall configuration diagram of a radar apparatus according to the sixth embodiment. FIG. 24 is a configuration diagram of a radar apparatus according to the sixth embodiment.

  Hereinafter, embodiments of an optical deflector, an optical scanning device, an image forming device, an image projection device, a head-up display device, and a radar device will be described in detail with reference to the accompanying drawings.

(First embodiment)
First, the optical deflector will be described. FIG. 1 is a top view showing the entire optical deflector according to the first embodiment. FIG. 2 is a side view seen from the AA cross section in FIG. FIG. 3 is a back view seen from the arrow B in FIG.

  As shown in FIGS. 1 to 3, the optical deflector of the present embodiment includes a mirror unit 10, torsion bar springs 20 a and 20 b, drive beams 30 a and 30 b, and a fixed base 40.

  The mirror unit 10 includes a reflection surface 12 that reflects light and a rib 11 that supports the reflection surface 12. The reflecting surface 12 of the mirror unit 10 has a thin film of metal such as aluminum or silver formed on the surface of a silicon substrate. The top view of FIG. 1 is a view seen from the normal direction of the reflecting surface 12 of the mirror unit 10.

  The torsion bar springs 20a and 20b are a kind of springs using a repulsive force when twisting a metal rod, and correspond to a pair of elastic indicating members. As shown in FIG. 1, one end of each of the torsion bar springs 20a and 20b is connected to both sides of the mirror part 10, and supports the mirror part 10 so as to be swingable.

  The drive beams 30a, 30b correspond to the torsion bar springs 20a, 20b on a one-to-one basis, one end is connected to the torsion bar springs 20a, 20b, and the other end is connected to the fixed base 40. Corresponds to a beam. That is, as shown in FIG. 1, the driving beams 30 a and 30 b have one end at the other end of the torsion bar springs 20 a and 20 b (the end opposite to the end connected to the mirror unit 10). ) And is arranged so as to sandwich the mirror portion 10 in the axial direction of the torsion bar springs 20a, 20b.

  Here, the configuration of the drive beam 30b will be described. In the drive beam 30b, a piezoelectric member 32b is fixed to a beam-like member 31b. Specifically, for example, as shown in FIGS. 1 and 2, the driving beam 30b is formed by a flat strip-like unimorph structure in which a piezoelectric member 32b is laminated on the surface of a beam-like member 31b. The drive beam 30a has the same configuration as the drive beam 30b, and a piezoelectric member 32a is fixed to the beam-shaped member 31a.

  The beam-like members 31a and 31b are arranged so as to protrude from the fixed base 40 in the same direction, and are arranged only on one side with respect to the central axis of the torsion bar springs 20a and 20b. Therefore, the optical deflector has a configuration in which the mirror portion 10 and the torsion bar springs 20a and 20b are cantilevered on the fixed base 40 by the beam-like members 31a and 31b of the drive beams 30a and 30b. With such a configuration, the beam-like members 31a and 31b are caused to bend and vibrate to cause torsional deformation in the torsion bar springs 20a and 20b, thereby causing the mirror unit 10 to rotate and vibrate. In addition, rotational vibration means the operation | movement which repeats the rotation of one direction and the rotation (return) of a reverse direction in the range of a predetermined angle around an axial center.

  Here, an electrical configuration for applying an electric field to the piezoelectric members 32a and 32b will be described. Hereinafter, the piezoelectric member 32a will be described with reference to the drawings, but the same applies to the piezoelectric member 32b.

  FIG. 4 is a diagram showing a wiring pattern in the vicinity of the root portion connected to the fixed base in the drive beam. FIG. 5 is a cross-sectional view taken along the line CC in FIG. FIG. 6 is a cross-sectional view taken along the line DD in FIG. 5 and 6 show cross sections of the wiring portions to the upper electrode 33a and the lower electrode 34a of the piezoelectric member 32a.

  The driving beam 30a is formed on the beam-like member 31a by sputtering in the order of the lower electrode 34a, the piezoelectric member 32a, and the upper electrode 33a, and is etched so that only necessary portions remain. . The material of the adhesive layer may be titanium (Ti), the upper electrode 33a and the lower electrode 34a may be platinum (Pt), and the piezoelectric member 32a may be lead zirconate titanate (PZT).

  When the wiring 50 is drawn out from the contact holes 51 and 52 and a voltage is applied between the upper electrode 33a and the lower electrode 34a, the volume changes due to the electrostrictive characteristics of the piezoelectric member 32a, and the in-plane direction of the surface of the beam-shaped member 31a Extends and contracts. As a result, the entire drive beam 30a warps and deforms. For the sake of explanation, the insulating layer 60 is omitted in FIG.

  In the present embodiment, an example of manufacturing by a film forming process has been described, but the piezoelectric member 32a may be manufactured by a method of attaching a bulk material. As the structure, the above-described silicon substrate uses a laminated SOI (Silicon on Insulator) substrate, and is formed of two types of silicon substrates, a device layer and a support layer. The mirror part 10, the torsion bar spring 20, and the beam-shaped member 31a are formed of a device layer, and the fixed base 40 is composed of both a device layer and a support layer.

  The optical deflector of the present embodiment is processed by a MEMS (Micro Electro Mechanical Systems) process, so that the mirror unit 10, the torsion bar springs 20a and 20b, and the drive beams 30a and 30b are integrally formed.

  Further, the longitudinal direction of the torsion bar springs 20a and 20b and the longitudinal direction of the drive beams 30a and 30b are arranged substantially orthogonally. For this reason, the rotational force generated by the bending of the drive beams 30a and 30b can be efficiently transmitted to the deformation in the twist direction of the torsion bar springs 20a and 20b.

  The drive beams 30a and 30b have a structure that supports the torsion bar springs 20a and 20b and the mirror unit 10 in a cantilever manner. For this reason, the driving beams 30a and 30b have free ends at their ends, and can vibrate with a large amplitude.

  Further, as shown in FIG. 1, the center of gravity G of the mirror portion 10 is in a direction close to the connecting portion side between the drive beams 30a and 30b and the fixed base 40 with respect to the central axis x of the torsion bar springs 20a and 20b. It is offset. By doing in this way, a moment can be generated by the vibration of the drive beams 30a and 30b, and the mirror unit 10 can be greatly rotated and amplified.

  The fixed base 40 is a base substrate of an optical deflector, and is formed of a support layer portion 41 and a device layer portion 42 as shown in FIG. The fixed base 40 is directed to one end of the drive beams 30a and 30b (the end connected to the torsion bar springs 20a and 20b) at the root portion to which the drive beams 30a and 30b are connected. The projections 43a and 43b project in the direction and support the drive beams 30a and 30b. The protrusion width W1 that is the width of the protrusions 43a and 43b is formed to be narrower than the drive beam width W2 that is the width of the drive beams 30a and 30b (see FIG. 3). Here, the fixed base is formed in a rectangular shape, and has a configuration in which the protruding portion protrudes from the longitudinal direction. However, the shape of the fixed base is not limited to this, and any shape may be used as long as the mirror portion can be fixed via a drive beam, a torsion bar spring, etc. Other shapes other than the rectangular shape It may be formed. For example, the shape of the fixed base may be a shape that surrounds the periphery of the mirror portion.

  When the mirror section 10 vibrates at a high amplitude and at a high speed, the driving beams 30a and 30b bend greatly, so that the stress at the roots of the driving beams 30a and 30b tends to increase. Therefore, in this embodiment, as shown in FIG. 3, by forming the protrusions 43a and 43b on the support layer portion 41 of the fixed base 40, the stress concentration generated at the root portions of the drive beams 30a and 30b is alleviated. be able to.

  Here, the protrusion amounts of the protrusions 43a and 43b (the length PL of the protrusions 43a and 43b in FIG. 3) calculated by FEM (Finite Element Method) simulation analysis and the root portions of the drive beams 30a and 30b The relationship with the stress of will be described. FIG. 7 is a diagram illustrating the relationship between the protrusion amount of the protrusion and the stress of the root portion of the drive beam.

  As shown in FIG. 7, the stress value is converted into the stress per rotation angle 1 deg of the mirror unit 10. If the protrusions 43a and 43b have a large amount of protrusion, the operation of the original drive beams 30a and 30b is hindered. In the present embodiment, the thickness T1 of the drive beams 30a and 30b is 40 um. Therefore, referring to FIG. 7, it can be seen that when the protrusion amount PL of the protrusions 43a and 43b and the thickness T1 of the drive beams 30a and 30b are substantially equal (PL≈T1), the stress value is low and appropriate. .

  FIG. 8 is a diagram showing another shape of the protrusion. Stress is concentrated at the corners of the protrusions provided on the fixed base 40. Therefore, in order to prevent this, as shown in FIG. 8, it is desirable that the corners and corners of the protrusions 44a and 44b have a fillet shape so as to be rounded. That is, in FIG. 8, the corners f1 and f2 and the corners f3 and f4 of the projection 44a and the corners f5 and f6 and the corners f7 and f8 of the projection 44b are fillet-shaped and rounded. Yes.

  FIG. 9 is a diagram showing another shape of the driving beam. Referring to FIG. 1, the above-described torsion bar springs 20a and 20b have inner end portions (end portions on the mirror portion 10 side) 30a-1 and 30b-1 at one end portion (free end side) of the drive beams 30a and 30b. It is connected to. On the other hand, as shown in FIG. 9, the torsion bar springs 20a and 20b are connected to the outer ends 70a-1 and 70b-1 of the drive beams 70a and 70b. As a result, the axial size of the drive beams 70a and 70b can be reduced.

  FIG. 10 is a diagram showing another shape of the driving beam. When it is desired to increase the rigidity of the driving beam due to factors such as an increase in the size of the mirror unit 10, two driving beams arranged on both sides of the mirror unit 10 are combined into one sheet as shown in FIG. 10. The drive beam 80 may be configured. Further, the drive beam 80 of FIG. 10 has a configuration having two protrusions 44a and 44b. However, since the width of the drive beam 80 becomes wide, a configuration having three or more protrusions may be used.

  As described above, in the optical deflector according to the first embodiment, driving is performed in a direction from the fixed base 40 toward the free ends of the driving beams 30a and 30b to the root portion of the fixed base 40 to which the driving beams 30a and 30b are connected. Protrusions 43a and 43b that protrude with a width narrower than the beams 30a and 30b and support the drive beams 30a and 30b are formed. As a result, the stress concentration generated at the root portions of the drive beams 30a and 30b can be dispersed to prevent breakage occurring at the root portions of the drive beams 30a and 30b.

  Further, by making the protruding amount of the protrusions 43a and 43b provided on the fixed base 40 substantially equal to the thickness of the driving beams 30a and 30b, the driving beams 30a and 30b maintain their original length and the driving beams 30a and 30b. It is possible to reduce the stress generated in the driving beam 30a and prevent the driving beams 30a and 30b from being damaged.

  Further, by forming fillets at the corners and corners like the protrusions 44a and 44b, stress concentration can be relaxed and damage to the drive beams 30a and 30b can be prevented.

(Second Embodiment)
In the optical deflector according to the first embodiment, the fixed base 40 is formed with the protrusions 43a and 43b protruding in the direction toward the free ends of the drive beams 30a and 30b. On the other hand, the optical deflector of the present embodiment retracts the support layer portion of the fixed portion base in the direction away from the mirror.

  FIG. 11 is a top view showing the entire optical deflector according to the second embodiment. FIG. 12 is a side view seen from the EE cross section in FIG. 13 and 14 are rear views as seen from the arrow F in FIG.

  As shown in FIGS. 11 to 13, the optical deflector of the present embodiment includes a mirror unit 10, torsion bar springs 20 a and 20 b, drive beams 70 a and 70 b, and a fixed base 40. Here, since the configurations of the mirror unit 10, the torsion bar springs 20a and 20b, and the fixed base 40 are the same as those in the first embodiment, the description thereof is omitted.

  The drive beams 70a and 70b correspond to the torsion bar springs 20a and 20b on a one-to-one basis, one end is connected to the torsion bar springs 20a and 20b, and the other end is connected to the fixed base 40. Corresponds to a beam. That is, as shown in FIG. 11, one end of each of the drive beams 70a and 70b is the other end of the torsion bar springs 20a and 20b (the end opposite to the end connected to the mirror 10). ) And is arranged so as to sandwich the mirror portion 10 in the axial direction of the torsion bar springs 20a, 20b. The shapes of the drive beams 70a and 70b are the same as those in FIG.

  Since the drive beams 70a and 70b are composed of a beam-like member 71b and a piezoelectric member 72b as in the optical deflector of the first embodiment, description of the configuration is omitted. Further, the electrical configuration of the drive beams 70a and 70b is the same as that of the first embodiment, and thus the description thereof is omitted.

  As in the first embodiment, the mirror 10, the torsion bar springs 20 a and 20 b, and the drive beams 70 a and 70 b are integrally formed by processing the optical deflector of the present embodiment by the MEMS process. ing.

  The fixed base 40 is a base substrate of an optical deflector, and as shown in FIG. 12, a support layer portion 41 to which drive beams 70a and 70b are connected, and a device layer portion 42 formed on the lower surface of the support layer portion 41. And have. As shown in FIG. 13, the support layer portion 41 of the fixed base 40 is separated from the mirror portion 10 at the base end portions 73 a and 73 b to which the drive beams 70 a and 70 b are connected with respect to the device layer portion 42. The vehicle has moved backward by a distance L. In FIG. 13, the root end portions 73a and 73b to which the driving beams 70a and 70b are connected are indicated by dotted lines. Here, the device layer portion 42 corresponds to the first layer portion, and the support layer portion 41 corresponds to the second layer portion.

  Further, as shown in FIG. 13, the fixed base 40 may be disposed using the protrusions 44a and 44b shown in FIG. That is, the fixed base 40 is directed to one end of the driving beams 70a and 70b (the end connected to the torsion bar springs 20a and 20b) at the root portion to which the driving beams 70a and 70b are connected. The projections 44a and 44b project in a direction narrower than the width of the drive beams 70a and 70b and support the drive beams 70a and 70b. The corners f1, f2 and corners f3, f4 of the projection 44a and the corners f5, f6 and corners f7, f8 of the projection 44b are fillet-shaped and rounded.

  As described above, in the optical deflector of the second embodiment, the support layer portion 41 of the fixed base 40 is retracted by the distance L in the direction away from the mirror portion 10 with respect to the device layer portion 42. With this configuration, the stress generated at the base portions of the driving beams 70a and 70b moves to the corners of the support layer portion 41 that has receded, and the stress is distributed to portions other than the driving beams 70a and 70b. Stress concentration can be relaxed.

  Further, as shown in FIG. 14, the corners f11 to f14 of the base portions of the drive beams 90a and 90b connected to the fixed base 40 are rounded in a fillet shape, so that the destruction due to the stress concentration is caused. Can be prevented.

(Third embodiment)
In the first and second embodiments, the optical deflector has been described. In the present embodiment, an optical scanning device (optical writing unit) using the optical deflector of the first and second embodiments, and an optical scanning device are provided. The image forming apparatus used will be described.

  First, the optical scanning device 100 will be described. FIG. 15 is an overall configuration diagram of the optical scanning device according to the third embodiment. FIG. 16 is a diagram showing the connection between the optical deflector and the driving means used in the optical scanning device of FIG.

  As shown in FIG. 15, in the optical scanning device 100 of the present embodiment, laser light from a light source unit 1020 such as a laser element passes through an imaging optical system 1021 such as a collimator lens, and is then deflected by an optical deflector 1022. The As this optical deflector 1022, an optical deflector having any one of the configurations of the first and second embodiments is used. Then, the laser beam deflected by the optical deflector 1022 passes through the scanning optical system 1023 including the first lens 1023a, the second lens 1023b, and the reflection mirror unit 1023c, and then the beam scanning surface (scanned surface) of the photosensitive drum 1002 is scanned. Surface). The scanning optical system 1023 forms a light beam in a spot shape on a beam scanning surface that is a surface to be scanned.

  As shown in FIG. 16, the optical deflector 1022 is electrically connected to the driving means 1024. The driving unit 1024 applies a driving voltage between the lower electrode and the upper electrode of the optical deflector 1022. As a result, the mirror portion of the optical deflector 1022 rotates to deflect the laser light, and the beam scanning surface of the photosensitive drum 1002 is optically scanned.

  As described above, the optical scanning device 100 using the optical deflectors of the first and second embodiments is optimal as a constituent member of an optical writing unit for an image forming apparatus such as a photographic printing printer or a copying machine.

  Next, an image forming apparatus 1000 in which the optical scanning device 100 is mounted as a constituent member of the optical writing unit will be described. FIG. 17 is an overall configuration diagram of the image forming apparatus. As shown in FIG. 17, the image forming apparatus 1000 according to the present embodiment includes an optical writing unit 1001 as an optical scanning apparatus, and writes an image by emitting laser light to a surface to be scanned. The photosensitive drum 1002 is an image carrier that provides a surface to be scanned as a scanning target by the optical writing unit 1001.

  The optical writing unit 1001 scans the surface (scanned surface) of the photosensitive drum 1002 in the axial direction of the photosensitive drum 1002 with one or a plurality of laser beams modulated by the recording signal. The photosensitive drum 1002 is rotationally driven in the direction of an arrow 1003, and an optical latent image is formed by optically scanning the surface charged by the charging unit 1004 by the optical writing unit 1001.

  The developing unit 1005 visualizes the formed electrostatic latent image as a toner image, and the transfer unit 1006 transfers the visualized toner image onto a recording paper 1007 (recording medium). The fixing unit 1008 fixes the transferred toner image on the recording paper 1007. Then, the cleaning unit 1009 removes residual toner on the surface portion of the photoconductive drum 1002 that has passed through the facing portion of the transfer unit 1006 of the photoconductive drum 1002.

  A configuration using a belt-like photoconductor in place of the photoconductor drum 1002 is also possible. Further, the toner image may be temporarily transferred to a transfer medium other than the recording paper, and the toner image may be transferred from the transfer medium to the recording paper and fixed.

  As shown in FIG. 17, the optical writing unit 1001 includes a light source unit 1020, a light source driving unit 1500, an optical deflector 1022, an imaging optical system 1021, a scanning optical system 1023, an integrated circuit 1024, and a circuit board. 1025.

  The light source unit 1020 is a laser element that emits one or more laser beams modulated by the recording signal, and the light source driving unit 1500 modulates the laser light. The optical deflector 1022 is the optical deflector of the first and second embodiments, and deflects the laser light. The imaging optical system 1021 forms an image of the laser beam modulated by the recording signal from the light source unit 1020 on the mirror surface of the mirror substrate of the optical deflector 1022. The scanning optical system 1023 forms one or a plurality of laser beams reflected and deflected by the mirror surface on the surface (scanned surface) of the photosensitive drum 1002. The optical deflector 1022 is incorporated in the optical writing unit 1001 in a form mounted on a circuit board 1025 together with an integrated circuit (driving means) 1024 for driving the optical deflector 1022.

  The optical deflector 1022 consumes less power for driving than the conventional rotary polygon mirror, which is advantageous for power saving of the image forming apparatus 1000. Further, since the wind noise during vibration of the mirror substrate of the optical deflector 1022 is smaller than that of the rotary polygon mirror, it is advantageous for improving the quietness of the image forming apparatus 1000. Furthermore, the optical deflector 1022 requires much less installation space than the rotary polygon mirror, and also has a small amount of heat generation, so that it can be easily downsized, and thus is advantageous for downsizing the image forming apparatus 1000. It is. In this manner, an optical scanning device or an image forming apparatus can be provided using an optical deflector that is not easily damaged.

  Note that the conveyance mechanism of the recording paper 1007, the driving mechanism of the photosensitive drum 1002, the control means such as the developing means 1005 and the transfer means 1006, the driving system of the light source unit 1020, and the like are the same as those in the conventional image forming apparatus. Is omitted.

(Fourth embodiment)
In the first and second embodiments, the optical deflector has been described. In the present embodiment, an image projection apparatus using the optical deflector of the first and second embodiments will be described.

  FIG. 18 is an overall configuration diagram of an image projection apparatus according to the fourth embodiment. FIG. 19 is a configuration diagram of an image projection apparatus according to the fourth embodiment.

  As illustrated in FIG. 19, the image projection apparatus 2000 according to the present embodiment includes a laser light source 2001 (2001-R, 2001) that emits laser light having three different wavelengths of red (R), green (G), and blue (B). -G, 2001-B) is attached. In the vicinity of the emission ends of the laser light sources 2001-R, 2001-G, and 2001-B, the diverging light emitted from the laser light sources 2001-R, 2001-G, and 2001-B is condensed into substantially parallel light. Lenses 2002 (2002-R, 2002-G, 2002-B) are arranged.

  The R, G, and B laser beams that are substantially parallel by the condensing lenses 2002-R, 2002-G, and 2002-B are combined by the combining prism 2005, and the optical deflector 2006 (MEMS two-dimensional reflection angle variable mirror). ). The combined laser light incident on the mirror unit of the optical deflector 2006 is two-dimensionally deflected and scanned by the optical deflector 2006 and projected onto the projection surface 2007 to project an image.

  As illustrated in FIG. 18, in the image projection apparatus 2000 of the present embodiment, the image generation unit 2011 generates an image signal according to image information. This image signal is sent to the light source drive circuit 2013 via the modulator 2012, and an image synchronization signal is sent to the scanner drive circuit 2014. The scanner drive circuit 2014 supplies a drive signal to the optical deflector 2006 according to the image synchronization signal. In FIG. 18, a three-wavelength laser and a synthesis prism are omitted.

  By this drive signal, the mirror unit 10 of the optical deflector 2006 vibrates with an amplitude of a predetermined angle (for example, about 10 deg) in two orthogonal directions. One optical deflector 2006 is not a two-dimensional one, but two one-dimensional scanning ones may be combined. In addition, a rotary scanning mirror such as a polygon mirror can be used for one scanning.

  Each of the three-wavelength laser light sources 2001 is intensity-modulated in accordance with the scanning timing of the optical deflector 2006, and projects two-dimensional image information onto the projection surface 2007. Intensity modulation may modulate the pulse width or the amplitude. The modulator 2012 drives the laser light source 2001 by performing pulse width modulation or amplitude modulation on the image signal and modulating the modulated signal into a current that can drive the laser light source 2001 by the light source driving circuit 2013. Thus, an image projector can be provided using an optical deflector that is not easily damaged.

(Fifth embodiment)
In the first and second embodiments, the optical deflector has been described. In the present embodiment, a head-up display device using a fourth image projection device will be described.

  FIG. 20 is an overall conceptual diagram of the head-up display device of the fifth embodiment. The head-up display device 300 of this embodiment is a window shield system that uses a windshield 350 of a vehicle as a part of a projection surface.

  In the head-up display device 300 according to the present embodiment, a base 303 is placed on a casing 301 having an exit window 306, and a vibration isolator 302 and an image forming unit 304 are provided thereon. The image formed by the image forming unit 304 is emitted from the emission unit of the image forming unit 304, reflected by the projection mirror 305, and then projected onto the windshield 350 (image projection unit). Then, the reflected light of the projected image is projected to an observer (for example, a driver) so as to reach the eyes of the observer. At this time, when viewed from the observer, an image irradiated on the windshield 350 a few meters ahead of the windshield 350 is recognized as a virtual image P as shown in FIG.

  FIG. 22 is a diagram illustrating details of the image forming unit according to the fifth embodiment. The dotted line frame in FIG. 22 is, for example, the image projection apparatus 2000 (see FIGS. 18 and 19) of the fourth embodiment. As shown in FIG. 22, although only one laser light source 401 is shown here, it is possible to perform color display using three colors of laser light as in the fourth embodiment.

  The laser light emitted from the laser light source 401 is converted into a substantially parallel light beam by the coupling lens 402 and is applied to the optical deflector 403. Incident light is scanned biaxially by the optical deflector 403 and irradiated onto the screen unit 405 via the scanning mirror 404. In addition, a desired image can be formed by modulating the laser light source 401 with the laser modulation means. The screen unit 405 corresponding to the display unit is formed of a diffusion plate, a microlens, or the like, and the observer visually recognizes the intermediate image formed here through the projection mirror 305 and the windshield 350 as a virtual image P. Become. Thus, a head-up display device can be provided using an optical deflector that is not easily damaged. The head-up display is mounted on a moving body such as a vehicle, an aircraft, a ship, or a robot. Therefore, a mobile device including a head-up display and a mobile body on which the head-up display is mounted can be provided.

(Sixth embodiment)
In the first and second embodiments, the optical deflector has been described. In the present embodiment, a radar apparatus using the optical deflector of the first and second embodiments will be described.

  FIG. 23 is an overall configuration diagram of a radar apparatus according to the sixth embodiment. FIG. 24 is a configuration diagram of a radar apparatus according to the sixth embodiment. As shown in FIG. 23, the radar apparatus 600 of this embodiment is attached to the front side of the vehicle and monitors the front of the vehicle.

  As shown in FIGS. 23 and 24, the laser light emitted from the laser light source 601 passes through a collimator lens 602 that is an optical system that makes diverging light substantially parallel light, and is uniaxially or biaxially directed by an optical deflector 610. It is scanned and irradiated to the object 650 in front of the vehicle. The photodetector 605 receives the laser beam reflected by the object 650 and passed through the condenser lens 606, and outputs a detection signal. The laser driver 603 that is a light source driving unit drives the laser light source 601, and the deflector driver 607 that is an optical deflector driving unit drives the optical deflector 610.

  The controller 604 controls the laser driver 603 and the deflector driver 607 and processes the detection signal output from the photodetector 605. That is, the controller 604 calculates the distance from the object 650 based on the difference between the timing at which the laser beam is emitted and the timing at which the photodetector 605 receives the laser beam. By scanning the laser beam with the optical deflector 610, the distance to the object 650 in a one-dimensional or two-dimensional range can be obtained. Thus, a radar apparatus can be provided using an optical deflector that is not easily damaged.

DESCRIPTION OF SYMBOLS 10 Mirror part 11 Rib 12 Reflecting surface 20a, 20b Torsion bar spring 30a, 30b, 70a, 70b, 80, 90a, 90b Driving beam 31a, 31b, 71b Beam-shaped member 32a, 32b, 72b Piezoelectric member 33a Upper electrode 34a Lower electrode Reference Signs List 40 Fixed base 41 Support layer portion 42 Device layer portion 43a, 43b, 44a, 44b Protrusion portion 50 Wiring 51, 52 Contact hole 60 Insulating layer 100 Optical scanning device 300 Head-up display device 600 Radar device 1000 Image forming device 2000 Image projection device

JP 2011-018026 A

Claims (10)

A fixed base;
A mirror portion having a reflecting surface for reflecting light;
A pair of elastic support members for supporting the mirror part;
A pair of drive beams, one-to-one corresponding to the pair of elastic support members, one end connected to the elastic support member, the other end connected to the fixed base, and a piezoelectric member fixed thereto; With
The drive beam has the mirror portion and the elastic support member supported on the fixed base in a cantilevered manner, and the mirror portion is rotated and vibrated.
The fixed base protrudes at a base portion to which the driving beam is connected in a direction toward the one end of the driving beam with a width narrower than the width of the driving beam, and a protruding portion that supports the driving beam. An optical deflector.   The optical deflector according to claim 1, wherein a protrusion amount of the protrusion is substantially equal to a thickness of the drive beam.   The optical deflector according to claim 1 or 2, wherein corners of the protrusions are rounded. A fixed base;
A mirror portion having a reflecting surface for reflecting light;
A pair of elastic support members for supporting the mirror part;
A pair of drive beams, one-to-one corresponding to the pair of elastic support members, one end connected to the elastic support member, the other end connected to the fixed base, and a piezoelectric member fixed thereto; With
The drive beam has the mirror portion and the elastic support member supported on the fixed base in a cantilevered manner, and the mirror portion is rotated and vibrated.
The fixed base includes a first layer portion connected to the driving beam and a second layer portion formed on a lower surface of the first layer portion, and the second layer portion is the first layer portion. On the other hand, the optical deflector is retracted in the direction away from the mirror part at the root part to which the drive beam is connected.   The said fixed base has a projection part which protrudes by the width | variety narrower than the width | variety of the said driving beam in the direction which goes to the said one end part of the said driving beam in the said base part, and supports the said driving beam. Light deflector. A light source;
The light deflector according to any one of claims 1 to 5, which deflects light from the light source;
And an optical system that forms an image of the deflected light in a spot shape on the surface to be scanned. An optical scanning device according to claim 6;
A photoreceptor on which a latent image is formed by scanning light;
A developing unit that visualizes the latent image into a toner image;
An image forming apparatus comprising: a transfer unit that transfers the toner image to a recording medium. A light source;
An optical system that makes divergent light from the light source substantially parallel light;
A modulator that modulates light output from the light source according to an image signal;
An image projection apparatus comprising: the optical deflector according to claim 1. An image projection device according to claim 8,
A display unit on which an image is projected from the image projection device;
A head-up display device comprising: an image projection unit that projects an image projected on the display unit to a user. An optical deflector according to any one of claims 1 to 5,
A light source that emits laser light;
An optical system that makes divergent light from the light source substantially parallel light;
A light source driving unit for driving the light source;
An optical deflector driving unit for driving the optical deflector;
A photodetector that receives reflected light of the laser beam emitted from the optical deflector and outputs a detection signal;
A radar apparatus comprising: a control unit that controls the light source driving unit and the optical deflector driving unit and processes the detection signal output from the photodetector.

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