JP2017049555A - Optical device and projection device comprising the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical device capable of superposing plural light beams comprising a peak in a different wavelength each other, capable of improving position accuracy of the plural light beams to be superposed, and achieving size reduction of the optical device, and a projection device comprising the same.SOLUTION: An optical device for superposing plural light beams comprising a peak in a different wavelength each other, comprises an optical member which comprises a single incident plane which the plural light beams enter, and a single emission plane from which the superposed plural light beams are emitted.SELECTED DRAWING: Figure 4

Description

  The present invention relates to an optical apparatus that superimposes a plurality of light beams having peaks at different wavelengths, and a projection apparatus including the same.

  As an optical device, an optical device that superimposes a plurality of light beams having peaks at mutually different wavelengths is conventionally known. For example, a plurality of light beams that have undergone luminance modulation are superimposed on a projection object such as a screen. The present invention can be applied to an optical scanning type projection apparatus (projector) that performs scanning.

  As such an optical device, it is common to superimpose a plurality of incident light beams using a dichroic mirror that reflects light in a specific wavelength range and transmits light in an exceptional wavelength range. .

  FIG. 6 is a schematic configuration diagram showing a general configuration for superposing a plurality of light beams in the conventional optical device 10X. In the example shown in FIG. 6, the plurality of light beams include a red laser beam Lr having a peak at a red wavelength, a green laser beam Lg having a peak at a green wavelength, and a blue having a peak at a blue wavelength. And three light beams with the laser beam Lb.

  As shown in FIG. 6, the conventional optical device 10X reflects the light in the green wavelength band, while transmitting the light in the exceptional wavelength band (light in the red wavelength in this example) 11X. And a second dichroic mirror 12X that reflects light in the wavelength region of blue while transmitting light in the exceptional wavelength region (in this example, light of red wavelength and light of green wavelength).

  The optical device 10X causes the first dichroic mirror 11X to pass the red laser beam Lr traveling in a predetermined traveling direction, while reflecting the green laser beam Lg so as to overlap the red laser beam Lr. Yes.

  The optical device 10X allows the second dichroic mirror 12X to pass the red laser beam Lr that has passed through the first dichroic mirror 11X and the green laser beam Lg that has been reflected from the first dichroic mirror 11X, while the red dichroic mirror 11X passes the red laser beam Lg. The blue laser beam Lb is reflected so as to overlap the laser beam Lr and the green laser beam Lg.

  In such a conventional optical apparatus, it is necessary to accurately position a plurality of (two in the example of FIG. 6) dichroic mirrors, and the positional accuracy of the superimposed light beams tends to deteriorate.

  In this regard, Patent Document 1 discloses an optical device including an optical member having a plurality of incident surfaces that respectively reflect a plurality of light beams.

JP 2007-534987 A

  However, since the optical device described in Patent Document 1 has a plurality of incident surfaces, the size of the optical device is easily increased.

  Therefore, the present invention is an optical device that superimposes a plurality of light beams having peaks at different wavelengths, and can improve the positional accuracy of the superposed multiple light beams, and further reduce the size of the optical device. It is an object of the present invention to provide an optical device capable of realizing the above and a projection device including the same.

  In order to solve the above-described problem, an optical device according to the present invention is an optical device that superimposes a plurality of light beams having peaks at different wavelengths, and a single incident light that enters the plurality of light beams. An optical member having a surface and a single emission surface for emitting the plurality of superimposed light beams is provided.

  In addition, a projection apparatus according to the present invention includes the optical apparatus according to the present invention, and the plurality of light beams whose luminances are modulated are overlapped by the optical apparatus and scanned on the projection target.

  In the present invention, the optical member superimposes the plurality of light beams incident from the single incident surface using light dispersion, and the plurality of the light beams superimposed are the single emission. The aspect currently set as the structure radiate | emitted from a surface can be illustrated.

  In this invention, the said optical member can illustrate the aspect which consists of a prism which has the said single incident surface and the said single output surface.

  In the present invention, the optical member is configured to superimpose the plurality of light beams incident from the single incident surface using light diffraction, and to superimpose the plurality of light beams on the single emission. The aspect currently set as the structure radiate | emitted from a surface can be illustrated.

  In the present invention, the optical member may include a first diffractive element having the single incident surface and a second diffractive element having the single exit surface.

  In the present invention, in the optical member, the single incident surface and the single emission surface are parallel or substantially parallel to each other, and the plurality of light beams are parallel or substantially parallel to each other. The plurality of light beams that are incident on the light incident surface and overlapped are emitted from the single light exit surface so as to be parallel or substantially parallel to the plurality of light beams incident on the single light incident surface. The mode to do can be illustrated.

  In the present invention, it is possible to exemplify an aspect in which the plurality of light beams are incident on the single incident surface obliquely.

  In the present invention, the plurality of light beams incident from the single incident surface are coaxially or substantially coaxially aligned by the optical member and are emitted from the emission surface as one composite light beam. Can be illustrated.

  According to the present invention, it is possible to improve the positional accuracy of a plurality of light beams to be superimposed, and to realize downsizing of the optical device.

It is a system block diagram which shows schematic structure of the projection apparatus provided with the optical apparatus which concerns on embodiment of this invention. It is a schematic block diagram which shows the internal structure of the light source device in the projection apparatus which concerns on 1st Embodiment. It is a schematic block diagram which shows the internal structure of the light source device in the projection apparatus which concerns on 2nd Embodiment. It is a schematic side view for demonstrating the optical member in the optical apparatus of the projector which concerns on 1st Embodiment. It is a schematic side view for demonstrating the optical member in the optical apparatus of the projector which concerns on 2nd Embodiment. It is a schematic block diagram which shows the general structure which superimposes several light beams in the conventional optical apparatus.

  Embodiments according to the present invention will be described below with reference to the drawings.

[Projector]
FIG. 1 is a system block diagram showing a schematic configuration of a projection apparatus 100 including an optical apparatus 10 according to an embodiment of the present invention. FIG. 2 is a schematic configuration diagram showing an internal configuration of the light source device 20 in the projection device 100 according to the first embodiment. FIG. 3 is a schematic configuration diagram showing an internal configuration of the light source device 20 in the projection device 100 according to the second embodiment.

  A projection device 100 shown in FIG. 1 is an optical scanning type projection device (projector), and includes an optical device 10, a light source device 20 (a laser light source device in this example), and a light source device drive device 30 (a laser driver in this example). (See FIG. 1), scanning device 40 (MEMS in this example), scanning device drive device 50 (specifically, MSMS driver) (see FIG. 1) and control device 60 (video processor in this example) (see FIG. 1) ).

  The projection device 100 performs the following operation under the instruction of the control device 60. In other words, the projection device 100 includes a plurality of (three in this example) light beams (specifically, three in this example) that have been subjected to luminance modulation by the light source device driving device 30 based on an image signal from the external device 200 (see FIG. 1). Laser beams Lr, Lg, and Lb) are emitted from the light source device 20 toward the optical device 10. The projection device 100 superimposes a plurality of light beams emitted from the light source device 20 on the optical device 10 and emits them toward the scanning device 40. Then, the projection device 100 causes the scanning device 40 driven by the scanning device driving device 50 to scan the projection beam SC (see FIG. 1) such as a screen with the light beam superimposed by the optical device 10.

  The projection apparatus 100 displays an image on the projection target SC by projecting a plurality of light beams superimposed on the projection target SC. Then, the projection apparatus 100 causes the user to visually recognize an image displayed on the projection target SC by the light reflected on the projection target SC or the light transmitted through the projection target SC.

  Note that the external device 200 may be provided integrally with the projection device 100. Further, in the projection apparatus 100, the projection target SC may be housed in one housing.

  The optical device 10 superimposes a plurality of light beams having peaks at different wavelengths. In this example, the plurality of light beams are a red laser beam Lr having a peak at a red wavelength, a green laser beam Lg having a peak at a green wavelength, and a blue laser beam having a peak at a blue wavelength. Three light beams with Lb are used. The optical device 10 will be described in detail later.

  The light source device 20 emits a red laser beam Lr, a green laser beam Lg, and a blue laser beam Lb in accordance with an image signal input from the external device 200 to the control device 60.

  2 and 3, the light source device 20 includes a plurality of light sources (three laser diodes 21r, 21b, 21b in this example) and a plurality of lenses (three collimator lenses 22r, 22g, 22b in this example). And a plurality of openings (in this example, three aperture members 23r, 23g, and 23b).

  The laser diode 21r emits a red laser beam Lr whose luminance is modulated in accordance with a red image signal among image signals input from the external device 200 to the control device 60. The laser diode 21g emits a green laser beam Lg whose luminance is modulated in accordance with a green image signal among image signals input from the external device 200 to the control device 60. The laser diode 21r emits a blue laser beam Lb whose luminance is modulated in accordance with a blue image signal among image signals input from the external device 200 to the control device 60.

  The collimator lens 22r makes the red laser beam Lr emitted from the laser diode 21r parallel light or substantially parallel light. The collimator lens 22g makes the green laser beam Lg emitted from the laser diode 21g parallel light or substantially parallel light. The collimator lens 22b converts the blue laser beam Lb emitted from the laser diode 21b into parallel light or substantially parallel light.

  The aperture member 23r shapes the red laser beam Lr from the collimator lens 22r into a predetermined beam diameter. The aperture member 23g shapes the green laser beam Lg from the collimator lens 22g into a predetermined beam diameter. The aperture member 23b shapes the blue laser beam Lb from the collimator lens 22b into a predetermined beam diameter.

  As shown in FIG. 1, the light source device driving device 30 is electrically connected to the output system of the control device 60. The light source device driving device 30 drives the light source device 20 based on an image signal from the external device 200 under the instruction of the control device 60. The light source device driving device 30 modulates the luminance of the laser beams Lr, Lg, and Lb emitted from the laser diodes 21r, 21g, and 21b in the light source device 20 toward the scanning device 40 via the optical device 10. Here, the light source device driving device 30 can control the laser beams Lr, Lg, and Lb emitted from the laser diodes 21r, 21g, and 21b by pulse width modulation or power modulation.

  As shown in FIG. 1, the scanning device 40 projects the laser beams Lr, Lg, and Lb from the optical device 10 onto the projection target SC while scanning.

  Specifically, the scanning device 40 is a mirror driving device including a mirror 41 and an actuator 42 such as a piezoelectric element that swings the mirror 41. The light source device 20 emits laser beams Lr, Lg, and Lb toward the mirror 41 in the scanning device 40 via the optical device 10.

  In this example, the scanning device 40 is a MEMS (Micro Electro Mechanical Systems).

  The scanning device 40 reciprocally rotates the mirror 41 around the first axis along the predetermined first direction (in the first rotation direction X) by the actuator 42, and laser beams Lr, Lg, Lb from the optical device 10. Are scanned in the main scanning direction, and the mirror 41 is reciprocally rotated around the second axis along the second direction orthogonal to the first direction (in the second rotation direction Y) by the actuator 42 to move the laser beam Lr. , Lg, and Lb are scanned in the sub-scanning direction. Thereby, the scanning device 40 can scan the laser beam Lr, Lg, Lb from the optical device 10 with respect to the projection target SC in both the main scanning direction and the sub-scanning direction by the mirror 41.

  As shown in FIG. 1, the scanning device driving device 50 is electrically connected to the output system of the control device 60. The scanning device drive device 50 operates the scanning device 40 based on an image signal from the external device 200 under the instruction of the control device 60. The scanning device driving device 50 causes the actuator 42 in the scanning device 40 to reciprocally rotate the mirror 41 both around the first axis (first rotation direction X) and around the second axis (second rotation direction Y). The laser beams Lr, Lg, and Lb are scanned in both the main scanning direction and the sub-scanning direction.

  As the light source device 20, the light source device driving device 30, the scanning device 40, and the scanning device driving device 50, conventionally known devices can be used, and further detailed description is omitted here.

  As shown in FIG. 1, the control device 60 includes a processing unit 61 composed of a microcomputer such as a CPU (Central Processing Unit), a nonvolatile memory such as a ROM (Read Only Memory), and a volatile memory such as a RAM (Random Access Memory). And a storage unit 62 including a volatile memory. In the control device 60, the processing unit 61 loads and executes a control program stored in advance in the ROM of the storage unit 62 on the RAM of the storage unit 62, thereby performing operation control of various components. . The RAM of the storage unit 62 provides a work area for work to the processing unit 61.

[Optical device]
FIG. 4 is a schematic side view for explaining the optical member 11 in the optical apparatus 10 of the projection apparatus 100 according to the first embodiment. FIG. 5 is a schematic side view for explaining the optical member 12 in the optical apparatus 10 of the projection apparatus 100 according to the second embodiment.

  As shown in FIGS. 4 and 5, the optical device 10 according to the first embodiment and the second embodiment includes a single laser beam Lr, Lg, and Lb on which laser beams Lr, Lg, and Lb are incident and superposed lasers. Optical members 11 and 12 having single exit surfaces 11b and 12b that emit beams Lr, Lg, and Lb are provided.

  Specifically, the laser diodes 21r, 21g, and 21b in the light source device 20 emit laser beams Lr, Lg, and Lb toward different positions on the single incident surfaces 11a and 12a in the optical members 11 and 12 of the optical device 10, respectively. To do. The optical device 10 includes laser beams Lr, Lg, and Lb that are incident from different positions on the single incident surfaces 11a and 12a of the optical members 11 and 12 except for all or one of the laser beams Lr, Lg, and Lb. The overlapping laser beams Lr, Lg, and Lb are emitted from a single emission surface 11b and 12b.

(First embodiment)
As shown in FIG. 4, the optical member 11 in the optical device 10 according to the first embodiment superimposes laser beams Lr, Lg, and Lb incident from a single incident surface 11a using light dispersion (refraction). In addition, the laser beams Lr, Lg, and Lb that are combined and superimposed are emitted from a single emission surface 11b.

  Specifically, the optical member 11 is configured to change the traveling direction of the laser beams Lr, Lg, and Lb incident from the single incident surface 11a using light dispersion.

  Here, “light dispersion” is a phenomenon that occurs because the refractive index (that is, the refraction angles θr, θg, θb) of the optical member 11 varies depending on the wavelength. Specifically, the shorter the wavelength of light, the greater the refractive index (that is, the refraction angles θr, θg, θb), and the greater the degree of light being bent by the optical member 11. In this example, the refraction angles θr, θg, and θb increase in the order of the red laser beam Lr, the green laser beam Lg, and the blue laser beam Lb. The refraction angles θr, θg, and θb are angles at which incident light is bent at a refraction position with respect to the traveling direction.

  The optical member 11 is a prism having a single incident surface 11a and a single output surface 11b. Here, the prism is a polyhedron (for example, a hexahedron) made of a light transmissive material (transparent material) such as glass, quartz, or resin having a refractive index different from that of the surrounding medium (specifically, air). It is a member. In this example, the optical member 11 is a rectangular parallelepiped and is made of a glass material or a resin material.

  Specifically, in the optical member 11 made of a prism, a single incident surface 11a and a single output surface 11b are parallel or substantially parallel to each other.

  In anticipation that the refraction angles θr, θg, and θb increase as the wavelengths of the laser beams Lr, Lg, and Lb become shorter in the optical member 11, the laser beams Lr, Lg, and Lb overlap on the single exit surface 11b. The laser diodes 21r, 21b, 21b (see FIG. 2) in the light source device 20 are positioned. Thereby, the incident position of the laser beams Lr, Lg, Lb to the single incident surface 11a and the emission position of the laser beams Lr, Lg, Lb from the single emission surface 11b can be determined.

  The optical member 11 allows the laser beams Lr, Lg, and Lb to enter the single incident surface 11a in parallel or substantially parallel to each other, and the superimposed laser beams Lr, Lg, and Lb enter the single incident surface 11a. The light is emitted from a single emission surface 11b so as to be parallel or substantially parallel to the laser beams Lr, Lg, and Lb.

  The optical device 10 is configured to cause the laser beams Lr, Lg, and Lb to enter the single incident surface 11a obliquely.

  Specifically, the laser diodes 21r, 21b, and 21b in the light source device 20 are arranged so that the laser beams Lr, Lg, and Lb are incident on the single incident surface 11a at an angle other than 90 degrees or approximately 90 degrees. Has been.

  In this example, the laser beams Lr, Lg, and Lb incident on the single incident surface 11a are aligned in a direction orthogonal to both the juxtaposed direction in which the laser diodes 21r, 21b, and 21b are juxtaposed and the traveling direction. Yes or almost complete. That is, the laser beams Lr, Lg, and Lb are located or substantially located on a virtual straight line along the juxtaposed direction.

(Second Embodiment)
As shown in FIG. 5, the optical member 12 in the optical device 10 according to the second embodiment superimposes and superimposes laser beams Lr, Lg, and Lb incident from a single incident surface 12a using light diffraction. The combined laser beams Lr, Lg, and Lb are emitted from a single emission surface 12b.

  Specifically, the optical member 12 is configured to change the traveling direction of the laser beams Lr, Lg, and Lb incident from the single incident surface 12a using light diffraction.

  Here, “light diffraction” is a phenomenon in which light circulates behind an obstacle and propagates. In “light diffraction”, the amount of diffraction (that is, diffraction angles φr, φg, φb) of the optical member 11 varies depending on the wavelength. Specifically, the longer the wavelength of light, the greater the amount of diffraction (that is, diffraction angles φr, φg, φb), and the greater the degree of light being bent by the optical member 12. In this example, the diffraction angles φb, φg, and φr increase in the order of the blue laser beam Lb, the green laser beam Lg, and the red laser beam Lr. The diffraction angles φb, φg, and φr are angles at which incident light is bent at the diffraction position with respect to the traveling direction.

  The optical member 12 includes a first diffractive element 121 having a single entrance surface 12a and a second diffractive element 122 having a single exit surface 12b. Here, a typical example of the diffractive element is an optically transparent diffractive element (so-called blazed diffractive element) in which a large number of grooves having a sawtooth cross-sectional shape are formed on one surface. In this example, the first diffractive element 121 and the second diffractive element 122 are produced by forming grooves that are parallel or substantially parallel to each other on one surface of a transparent plate-like substrate made of a glass material or a resin material. Can do. The first diffractive element 121 and the second diffractive element 122 have the same diffraction characteristics (specifically, grooves having the same or substantially the same shape and the same or substantially the same interval). The 1st diffraction element 121 and the 2nd diffraction element 122 can be arrange | positioned so that the surface by the side of a groove may mutually oppose. For example, the second diffractive element 122 is disposed at the same position as the first diffractive element 121 by moving the second diffractive element 122 toward the groove side and rotating 180 degrees (inverted vertically and horizontally). It can be an arrangement position. That is, the first diffractive element 121 and the second diffractive element 122 are point-symmetric.

  Specifically, the optical member 12 including the first diffractive element 121 and the second diffractive element 122 includes a single incident surface 12 a in the first diffractive element 121 and a single exit surface 12 b in the second diffractive element 122. Are parallel or substantially parallel to each other.

  In anticipation that the diffraction angles φr, φg, and φb increase as the wavelengths of the laser beams Lr, Lg, and Lb increase in the optical member 12, the laser beams Lr, Lg, and Lb overlap on the single exit surface 12b. The laser diodes 21r, 21b, and 21b (see FIG. 3) in the light source device 20 are positioned. Thereby, the incident position of the laser beams Lr, Lg, Lb on the single incident surface 12a and the emission position of the laser beams Lr, Lg, Lb from the single emission surface 12b can be determined.

  The optical member 12 makes the laser beams Lr, Lg, and Lb enter the single incident surface 12a in parallel or substantially parallel to each other, and the superimposed laser beams Lr, Lg, and Lb enter the single incident surface 12a. The light is emitted from a single emission surface 12b so as to be parallel or substantially parallel to the laser beams Lr, Lg, and Lb.

  The optical device 10 is configured to cause the laser beams Lr, Lg, and Lb to enter the single incident surface 12a obliquely.

  Specifically, the laser diodes 21r, 21b, and 21b in the light source device 20 are arranged so that the laser beams Lr, Lg, and Lb are incident on the single incident surface 12a at an angle other than 90 degrees or approximately 90 degrees. Has been.

  In this example, the laser beams Lr, Lg, and Lb incident on the single incident surface 21a are aligned in a direction orthogonal to both the direction in which the laser diodes 21r, 21b, and 21b are arranged in parallel and the traveling direction. Yes or almost complete. That is, the laser beams Lr, Lg, and Lb are located or substantially located on a virtual straight line along the juxtaposed direction.

(Third embodiment)
In the optical device 10 according to the third embodiment, in the first embodiment and the second embodiment, the laser beams Lr, Lg, and Lb incident from the single incident surfaces 11a and 12a are coaxially or substantially the same by the optical members 11 and 12, respectively. It is set as the structure radiate | emitted from the single output surface 11b, 12b as one compound light beam in alignment with the same axis | shaft. The optical axes of the laser beams Lr, Lg, and Lb emitted from the single emission surfaces 11b and 12b coincide with each other or substantially coincide with each other.

  Specifically, in the optical device 10 according to the third embodiment, the refraction angles θr, θg, and θb are increased as the wavelengths of the laser beams Lr, Lg, and Lb are shortened in the optical member 11 in the first embodiment. In anticipation, the laser diodes 21r, 21b, and 21b (see FIG. 2) in the light source device 20 are positioned so that the optical axes of the laser beams Lr, Lg, and Lb coincide with each other on the single emission surface 11b. . Thereby, the incident position of the laser beams Lr, Lg, Lb to the single incident surface 11a and the emission position of the laser beams Lr, Lg, Lb from the single emission surface 11b can be determined.

  The optical device 10 according to the third embodiment expects that the diffraction angles φr, φg, and φb increase as the wavelengths of the laser beams Lr, Lg, and Lb increase in the optical member 12 in the second embodiment. The laser diodes 21r, 21b, and 21b (see FIG. 3) in the light source device 20 are positioned so that the optical axes of the laser beams Lr, Lg, and Lb coincide with each other on the single emission surface 12b. Thereby, the incident position of the laser beams Lr, Lg, Lb on the single incident surface 12a and the emission position of the laser beams Lr, Lg, Lb from the single emission surface 12b can be determined.

(About this embodiment)
As described above, according to the present embodiment, a plurality of light beams (in this example, laser beams Lr, Lg, Lb) are incident on the single incident surfaces 11a, 12a by the optical members 11, 12. On the other hand, a plurality of superposed light beams (in this example, laser beams Lr, Lg, Lb) are emitted from a single exit surface 11b, 12b, so that the plurality of light beams can be easily superposed, Thereby, the positional accuracy of the multiple light beams to be superimposed can be improved. In addition, since the optical members 11 and 12 are incident surfaces 11a and 12a on which a plurality of light beams (in this example, laser beams Lr, Lg, and Lb) are incident, they are a single incident surface. There is no need for a plurality of incident surfaces that respectively reflect a plurality of light beams, and thus the optical device 10 can be reduced in size.

  In the first and third embodiments, the optical member 11 uses a plurality of light beams (laser beams Lr, Lg, and Lb in this example) incident from a single incident surface 11a by using light dispersion. Thus, the configuration is such that a plurality of superimposed light beams are emitted from a single emission surface 11b, so that a configuration in which the plurality of light beams are superimposed is an optical member utilizing light dispersion. 11 simple configurations can be realized easily and easily.

  In the first embodiment and the third embodiment, the optical member 11 is composed of a prism having a single incident surface 11a and a single output surface 12b, so that a plurality of light beams (in this example) Then, the configuration of superimposing the laser beams Lr, Lg, and Lb) can be realized easily and easily with the single optical member 11 without using a plurality of components as in the conventional configuration.

  In the second embodiment and the third embodiment, the optical member 12 uses a plurality of light beams (laser beams Lr, Lg, and Lb in this example) incident from a single incident surface 12a by using light diffraction. Thus, the configuration is such that a plurality of superimposed light beams are emitted from a single emission surface 12b, so that a configuration in which the plurality of light beams are superimposed is an optical member utilizing light diffraction. It can be realized easily and easily with 12 simple configurations.

  In the second and third embodiments, the optical member 12 includes a first diffractive element 121 having a single incident surface 12a and a second diffractive element 122 having a single exit surface 12b. Therefore, a configuration in which a plurality of light beams (in this example, laser beams Lr, Lg, and Lb) are superposed is simple and easy by using conventional diffraction elements as the first diffraction element 121 and the second diffraction element 122. Can be realized.

  In the first to third embodiments, the optical members 11 and 12 have a single incident surface 11a and 12a and a single output surface 11b and 12b that are parallel or substantially parallel to each other. A plurality of light beams (in this example, laser beams Lr, Lg, and Lb) are incident on the single incident surfaces 11a and 12a in parallel or substantially in parallel with each other, and a plurality of superimposed light beams (in this example, laser beams Lr). , Lg, Lb) are emitted from the single exit surfaces 11b, 12b so as to be parallel or substantially parallel to the multiple light beams incident on the single entrance surfaces 11a, 12a. The configuration in which the beams are superimposed and emitted from the single exit surfaces 11b and 12b is simple and easy (specifically, in the first embodiment, the simple shape of the optical member 11 is used easily and easily in the second embodiment). In form, the first diffraction element Simply and easily by 21 and simple disposed configuration of the second diffraction element 122) can be realized.

  In the first to third embodiments, a plurality of light beams (in this example, laser beams Lr, Lg, and Lb) are obliquely incident on the single incident surfaces 11a and 12a. As a result, the interval between the single incident surfaces 11a and 12a between the multiple light beams incident on the single incident surfaces 11a and 12a can be increased. The incident position of the light beam of the book can be easily adjusted.

  In the third embodiment, a plurality of light beams (laser beams Lr, Lg, Lb in this example) incident from a single incident surface 11a, 12a are coaxially or substantially coaxially aligned by the optical members 11, 12. When the optical device 10 is applied to the projection device 100, a plurality of light beams to be scanned on the projection target SC are obtained by emitting the light from the single emission surfaces 11b and 12b as one composite light beam. The light beams can be handled as a single composite light beam that is coaxially or substantially coaxially arranged, whereby the projector 100 can be configured simply.

(Other embodiments)
In the present embodiment, the optical device 10 is applied to the projection device 100. However, the optical device 10 may be applied to any device as long as it uses a plurality of superimposed light beams. The present invention can also be applied to a laser writing device that writes a latent image (specifically, an electrostatic latent image) on a carrier (specifically, a photosensitive member).

  The present invention is not limited to the embodiment described above, and can be implemented in various other forms. Therefore, such an embodiment is merely an example in all respects and should not be interpreted in a limited manner. The scope of the present invention is shown by the scope of claims, and is not restricted by the text of the specification. Further, all modifications and changes belonging to the equivalent scope of the claims are within the scope of the present invention.

DESCRIPTION OF SYMBOLS 10 Optical apparatus 11 Optical member 11a Single entrance surface 11b Single exit surface 12 Optical member 12a Single entrance surface 12b Single exit surface 20 Light source device 21b Blue laser diode 21g Green laser diode 21r Red laser Diode 22b Collimator lens 22g Collimator lens 22r Collimator lens 23b Aperture member 23g Aperture member 23r Aperture member 30 Light source device driving device 40 Scanning device 41 Mirror 42 Actuator 50 Scanning device driving device 60 Control device 61 Processing unit 62 Storage unit 100 Projection device 121 First diffraction element 122 Second diffraction element 200 External device Lb Blue laser beam Lg Green laser beam Lr Red laser beam SC Projected object θb Refraction angle θg of blue laser beam Diffraction angle of the diffraction angle φr red laser beam diffraction angle φg green laser beam refraction angles φb blue laser beam refraction angles θr red laser beam color laser beam

Claims (9)

An optical device for superimposing a plurality of light beams having peaks at different wavelengths,
An optical device comprising: an optical member having a single incident surface on which the plurality of light beams are incident and a single emission surface on which the plurality of superimposed light beams are emitted. The optical device according to claim 1,
The optical member superimposes the plurality of light beams incident from the single incident surface using light dispersion, and emits the superimposed light beams from the single emission surface. An optical device characterized by being configured. The optical device according to claim 2,
The optical device is composed of a prism having the single entrance surface and the single exit surface. The optical device according to claim 1,
The optical member superimposes the plurality of light beams incident from the single incident surface using light diffraction, and emits the superimposed light beams from the single emission surface. An optical device characterized by being configured. The optical device according to claim 4,
The optical device includes a first diffractive element having the single incident surface and a second diffractive element having the single exit surface. An optical device according to any one of claims 1 to 5,
In the optical member, the single entrance surface and the single exit surface are parallel or substantially parallel to each other,
The plurality of light beams are incident on the single incident surface in parallel or substantially parallel to each other, and the plurality of superimposed light beams are incident on the single incident surface. An optical device that emits light from the single exit surface so as to be parallel or substantially parallel. An optical device according to any one of claims 1 to 6,
An optical device characterized in that the plurality of light beams are incident on the single incident surface obliquely. An optical device according to any one of claims 1 to 7,
The plurality of light beams incident from the single incident surface are coaxially or substantially coaxially aligned by the optical member and emitted from the emission surface as a single composite light beam. Optical device.   An optical device according to any one of claims 1 to 8, wherein the plurality of light beams that have undergone luminance modulation are superimposed on the optical device and scanned on a projection object. Projection device.

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