JPWO2014162501A1 - Light source unit - Google Patents

Abstract

The light source unit includes a combining element that combines the first beam and the second beam, a first pinhole portion having a first hole into which the beam emitted from the combining element is incident, and the combining element through the first hole. A light receiving element that receives the emitted beam and outputs a light reception signal corresponding to a light receiving position of the beam; and a driving unit that moves the first pinhole portion and / or the light receiving element. When the beam is irradiated outside the predetermined range of the element, the first pinhole portion and / or the light receiving element is moved so that the beam is irradiated within the predetermined range.

Description

  The present invention relates to a technical field for detecting an optical axis shift.

  This type of technique is proposed in Patent Document 1, for example. Japanese Patent Application Laid-Open No. 2004-133620 proposes a technique for causing a beam from a plurality of light sources to enter a light receiving element through a pinhole and detecting an optical axis shift based on an output signal of the light receiving element. Patent Document 1 proposes correcting an optical axis deviation by moving an optical element (a lens or a beam splitter) based on the detected optical axis deviation.

WO2009-154134

  In the technique described in Patent Document 1 described above, if an optical axis shift occurs such that the beam is irradiated outside the detectable range of the light receiving element, the optical axis shift cannot be detected. That is, with the technique described in Patent Document 1, it has been difficult to appropriately ensure a wide detection range for optical axis misalignment. Here, for example, if the size of the pinhole is increased, the detection range of the optical axis deviation can be expanded, but this tends to lower the detection accuracy of the optical axis deviation.

  Examples of the problem to be solved by the present invention are as described above. An object of the present invention is to provide a light source unit and the like that can appropriately ensure both the detection accuracy and the detection range of an optical axis deviation.

  In the invention described in claim, the light source unit includes a combining element that combines the first beam and the second beam, a first pinhole portion having a first hole into which the beam emitted from the combining element is incident, A light receiving element that receives a beam emitted from the combining element through the first hole and outputs a light receiving signal according to a light receiving position of the beam, and moves the first pinhole portion and / or the light receiving element. Driving means for causing the first pinhole portion and / or the driving means to emit the beam within the predetermined range when the beam is irradiated outside the predetermined range of the light receiving element. Alternatively, the light receiving element is moved.

1 shows a configuration of a projection apparatus according to a first embodiment. The specific example of a light-receiving part is shown. The figure for demonstrating the reason for performing control which concerns on 1st Example is shown. The figure for demonstrating the control method concerning 1st Example concretely is shown. The figure for demonstrating the reason why a beam can be irradiated within the detectable range of a light-receiving part when a pinhole part is moved is shown. The structure of the projection apparatus which concerns on 2nd Example is shown. The top view of the pinhole part which concerns on 2nd Example is shown. The figure for demonstrating the control method concerning 2nd Example concretely is shown. The structure of the projection apparatus which concerns on 3rd Example is shown. The top view of the pinhole part which concerns on 3rd Example is shown. The figure for demonstrating the control method concerning 3rd Example concretely is shown.

  In one aspect of the present invention, the light source unit includes a combining element that combines the first beam and the second beam, a first pinhole unit having a first hole into which the beam emitted from the combining element is incident, A light receiving element that receives a beam emitted from the combining element through the first hole and outputs a light receiving signal according to a light receiving position of the beam, and moves the first pinhole portion and / or the light receiving element. Driving means for causing the first pinhole portion and / or the driving means to emit the beam within the predetermined range when the beam is irradiated outside the predetermined range of the light receiving element. Alternatively, the light receiving element is moved.

  In the above light source unit, when the optical axis shift occurs such that a beam is irradiated outside a predetermined range of the light receiving element (corresponding to a detectable range of the light receiving element), the first pinhole portion and / or By moving the light receiving element, the beam is irradiated within a predetermined range of the light receiving element. Thereby, the wide detection range about an optical axis offset is securable. Here, if the size of the spot formed on the light receiving element is reduced, the detection accuracy of the optical axis deviation can be improved. However, in this case, the irradiation position of the beam tends to be out of the predetermined range of the light receiving element. That is, the detection range of the optical axis deviation tends to be narrowed. However, according to the above light source unit, by moving the first pinhole portion and / or the light receiving element, it is possible to irradiate a beam within a predetermined range of the light receiving element. it can. Therefore, according to the light source unit described above, it is possible to secure the detection accuracy of the optical axis deviation by adopting a configuration in which the size of the spot formed on the light receiving element is as small as possible. From the above, according to the light source unit described above, it is possible to appropriately ensure both the detection accuracy and the detection range of the optical axis deviation.

  In one aspect of the above light source unit, the driving means may emit the first pinhole portion when the beam emitted from the combining element and passing through the first hole is irradiated outside a predetermined range of the light receiving element. The first pinhole portion and / or the light receiving element are moved so that the distance between the light receiving element and the light receiving element is shortened. Thereby, the beam irradiated outside the predetermined range of the light receiving element can be appropriately irradiated within the predetermined range.

  In another aspect of the light source unit described above, the light source unit further includes a second pinhole portion having a second hole larger than the first hole, and the beam emitted from the combining element is transmitted through the second hole. When the beam that is incident on one hole and is emitted from the combining element and passes through the first hole and the second hole is irradiated outside the predetermined range of the light receiving element, the first pin The first pinhole portion is moved to a position where the beam does not enter the hole portion. Also by this, the beam irradiated outside the predetermined range of the light receiving element can be appropriately irradiated within the predetermined range.

  In another aspect of the light source unit, the first pinhole portion includes not only the first hole but also a second hole larger than the first hole, and the driving unit includes the combining element. When the beam emitted from the first hole and irradiated through the first hole is irradiated outside the predetermined range of the light receiving element, the first pinhole is positioned at a position where the beam emitted from the combining element passes through the second hole. Move the part. Also by this, the beam irradiated outside the predetermined range of the light receiving element can be appropriately irradiated within the predetermined range.

  Preferably, the light source unit further includes control means for controlling light emission of the first beam and the second beam, and the control means emits one of the first beam and the second beam. The light receiving element receives one of the first beam and the second beam emitted by the control means, and outputs a light reception signal corresponding to the light receiving position of the beam.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

[First embodiment]
First, the first embodiment will be described.

(Device configuration)
FIG. 1 shows a configuration of a projection apparatus 1a according to the first embodiment. As shown in FIG. 1, the projection apparatus 1a according to the first embodiment mainly includes an image signal input unit 2, a video ASIC 3, a frame memory 4, a ROM 5, a RAM 6, a laser driver ASIC 7, and a MEMS mirror. The control part 8, the laser light source unit 9a, and the drive part 20a are provided.

  For example, the projection device 1a is used by being mounted on a vehicle. In one example, the projection apparatus 1a is applied to a head-up display that visually recognizes an image as a virtual image from the position (eye point) of the user's eyes. In addition, in the laser light source unit 9a in FIG. 1, the figure which cut | disconnected some structural elements in the surface along the advancing direction of light is shown (FIG.6 and FIG.9 is also the same).

  The image signal input unit 2 receives an image signal input from the outside and outputs it to the video ASIC 3. The video ASIC 3 is a block that controls the laser driver ASIC 7 and the MEMS mirror control unit 8 based on the image signal input from the image signal input unit 2 and the scanning position information input from the MEMS mirror 10, and the ASIC (Application Specific Integrated). Circuit). The video ASIC 3 corresponds to an example of “control means” in the present invention. The video ASIC 3 includes a synchronization / image separation unit 31, a bit data conversion unit 32, a light emission pattern conversion unit 33, and a timing controller 34.

  The synchronization / image separation unit 31 separates the image data displayed on the image display unit and the synchronization signal from the image signal input from the image signal input unit 2 and writes the image data to the frame memory 4. The bit data converter 32 reads the image data written in the frame memory 4 and converts it into bit data. The light emission pattern conversion unit 33 converts the bit data converted by the bit data conversion unit 32 into a signal representing the light emission pattern of each laser. The timing controller 34 controls the operation timing of the synchronization / image separation unit 31 and the bit data conversion unit 32. The timing controller 34 also controls the operation timing of the MEMS mirror control unit 8 described later.

  In the frame memory 4, the image data separated by the synchronization / image separation unit 31 is written. The ROM 5 stores a control program and data for operating the video ASIC 3. Various data are sequentially read from and written into the RAM 6 as a work memory when the video ASIC 3 operates.

  The laser driver ASIC 7 is a block that generates a signal for driving a laser diode (LD) provided in a laser light source unit 9a described later, and is configured as an ASIC. The laser driver ASIC 7 includes a red laser driving circuit 71, a blue laser driving circuit 72, and a green laser driving circuit 73. The red laser driving circuit 71 drives the red laser LD1 based on the signal output from the light emission pattern conversion unit 33. The blue laser drive circuit 72 drives the blue laser LD2 based on the signal output from the light emission pattern conversion unit 33. The green laser drive circuit 73 drives the green laser LD3 based on the signal output from the light emission pattern conversion unit 33.

  A MEMS (Micro Electro Mechanical Systems) mirror control unit 8 controls the MEMS mirror 10 based on a signal output from the timing controller 34. The MEMS mirror control unit 8 includes a servo circuit 81 and a driver circuit 82. The servo circuit 81 controls the operation of the MEMS mirror 10 based on a signal from the timing controller. The driver circuit 82 amplifies the control signal of the MEMS mirror 10 output from the servo circuit 81 to a predetermined level and outputs the amplified signal.

  The laser light source unit 9a mainly functions to emit laser light based on a drive signal output from the laser driver ASIC 7. Specifically, the laser light source unit 9a includes a red laser LD1, a blue laser LD2, a green laser LD3, collimator lenses 91a, 91b, and 91c, dichroic mirrors 92a and 92b, a beam splitter 93, and a MEMS mirror 10. And a pinhole portion 12a, a light receiving portion 13, and a transmission window 14.

  The red laser LD1 emits red laser light, the blue laser LD2 emits blue laser light, and the green laser LD3 emits green laser light. Hereinafter, when the red laser LD1, the blue laser LD2, and the green laser LD3 are used without being distinguished from each other, they are simply referred to as “laser LD”, and the red laser light, the blue laser light, and the green laser light are used without being distinguished from each other. In this case, it is simply expressed as “laser light”. Further, in this specification, laser light is appropriately expressed as “beam”.

  The collimator lenses 91a, 91b, and 91c convert the red laser light, the blue laser light, and the green laser light into parallel light, respectively. The dichroic mirror 92a reflects the red laser light passing through the collimator lens 91a and transmits the green laser light passing through the collimator lens 91c. The dichroic mirror 92b transmits the red laser light and the green laser light that have passed through the dichroic mirror 92a, and reflects the blue laser light that has passed through the collimator lens 91b. The dichroic mirrors 92a and 92b are examples of the “composite element” in the present invention. The beam splitter 93 divides the laser light emitted from the dichroic mirror 92b in this manner, reflects a part of the laser light, and transmits the remaining part of the laser light. The laser light reflected by the beam splitter 93 is incident on the MEMS mirror 10, and the laser light transmitted through the beam splitter 93 is incident on the pinhole portion 12a.

  The MEMS mirror 10 reflects the beam (laser light) reflected by the beam splitter 93 toward the diffusion plate 11 through the transmission window 14. Specifically, the MEMS mirror 10 operates to scan the diffusion plate 11 with a beam under the control of the MEMS mirror control unit 8 in order to display an image input to the image signal input unit 2, and Scan position information at that time (for example, information such as a mirror angle) is output to the video ASIC 3. The diffuser plate 11 functions as a screen that forms an intermediate image when the beam reflected by the MEMS mirror 10 is incident through the transmission window 14. For example, EPE (Exit-Pupil Expander) can be used as the diffusion plate 11.

  The pinhole portion 12a is formed with a pinhole 12a1 as a through hole. The beam (laser light) transmitted through the beam splitter 93 as described above passes through the pinhole 12a1 formed in the pinhole portion 12a and enters the light receiving portion 13. Further, the pinhole portion 12a is configured to be movable in a direction (see arrow A2) substantially along the traveling direction of the beam from the beam splitter 93 to the light receiving portion 13 when driven by the driving portion 20a. The pinhole portion 12a corresponds to an example of the “first pinhole portion” in the present invention, and the pinhole 12a1 corresponds to an example of the “first hole” in the present invention.

  The beam that has passed through the pinhole 12a1 of the pinhole portion 12a is incident on the light receiving portion 13. The light receiving unit 13 is a photoelectric conversion element (for example, a four-divided light receiving element) such as a photodetector, and outputs a light receiving signal Sd1 corresponding to the light receiving position of the beam to the video ASIC 3. The light receiving unit 13 corresponds to an example of a “light receiving element” in the present invention.

  Here, a specific example of the light receiving unit 13 will be described with reference to FIG. FIG. 2 is a view of the light receiving unit 13 observed from the direction of the arrow A1 in FIG. As shown in FIG. 2, the light receiving unit 13 includes four light receiving elements 13 a to 13 d, and a spot SP corresponding to the beam reflected by the MEMS mirror 10 is formed. Each of the light receiving elements 13a to 13d outputs a signal corresponding to the area irradiated with the beam. The light receiving unit 13 subtracts the value obtained by adding the output value of the light receiving element 13b and the output value of the light receiving element 13d from the value obtained by adding the output value of the light receiving element 13a and the output value of the light receiving element 13c, This is output as an X deviation signal indicating the optical axis deviation in the direction (hereinafter referred to as “right and left optical axis deviation” as appropriate). The light receiving unit 13 subtracts the value obtained by adding the output value of the light receiving element 13c and the output value of the light receiving element 13d from the value obtained by adding the output value of the light receiving element 13a and the output value of the light receiving element 13b. , Y direction optical axis deviation (hereinafter referred to as “vertical direction optical axis deviation” as appropriate) is output as a Y deviation signal. The light receiving unit 13 outputs a signal including such an X deviation signal and a Y deviation signal to the video ASIC 3 as the above-described light reception signal Sd1.

  Returning to FIG. The video ASIC 3 detects the optical axis shift of the red laser LD1, the blue laser LD2, and the green laser LD3 based on the light reception signal Sd1 from the light receiving unit 13. In this case, the video ASIC 3 is based on the received light signal Sd1 for each of the red laser light, the blue laser light, and the green laser light obtained when the red laser LD1, the blue laser LD2, and the green laser LD3 are individually emitted. Thus, the optical axis deviation for each laser LD is detected. Then, the video ASIC 3 performs processing for correcting the optical axis deviation based on the detected optical axis deviation. For example, the video ASIC 3 corrects the optical axis deviation by controlling the emission timing of the laser beam (that is, the modulation timing of the laser LD with respect to the movement of the MEMS mirror 10).

  The drive unit 20a is configured by, for example, an actuator or a stepping motor, and moves the pinhole unit 12a in a direction substantially along the beam traveling direction (see arrow A2). The drive unit 20a is controlled by the video ASIC3. Details will be described later. The drive unit 20a (which may include the video ASIC 3) corresponds to an example of “drive means” in the present invention.

  The configuration including the laser light source unit 9 and the drive unit 20a corresponds to an example of the “light source unit” in the present invention.

(Control method)
Next, a control method according to the first embodiment will be described. In the first embodiment, when the beam is irradiated outside the detectable range of the light receiving unit 13, the pinhole unit 12a is moved by the driving unit 20a so that the beam is irradiated within the detectable range of the light receiving unit 13. Let Specifically, in the first embodiment, the video ASIC 3 is configured such that when the optical axis shift occurs such that the beam is irradiated outside the detectable range of the light receiving unit 13, the pinhole unit is driven by the driving unit 20a. 12 a is moved in a direction approaching the light receiving unit 13.

  The reason for performing such control will be described with reference to FIG. 3A and 3B show a state in which the beam that has passed through the pinhole 12a1 of the pinhole portion 12a is incident on the light receiving portion 13 on the left side, and the beam that has passed through the pinhole 12a1 on the right side. The spots SP11 and SP12 formed on the light receiving unit 13 are indicated by. FIG. 3A shows a diagram when the optical axis deviation is small, and FIG. 3B shows a diagram when the optical axis deviation is large.

  As shown in FIG. 3A, when the optical axis deviation is small, the spot SP11 is formed at a position across all of the light receiving elements 13a to 13d in the light receiving unit 13. In this case, since signals are output from all of the light receiving elements 13a to 13d, the video ASIC 3 can appropriately detect the optical axis deviation based on the light receiving signal Sd1 from the light receiving unit 13. 3A, when the spot SP11 is formed at a position across all of the light receiving elements 13a to 13d (in other words, when the center C1 of the light receiving unit 13 is included in the range of the spot SP11). Corresponds to the case where the beam is irradiated within the detectable range of the light receiving unit 13.

  On the other hand, as shown in FIG. 3B, when the optical axis shift is large, the spot SP <b> 12 is not formed at a position across all of the light receiving elements 13 a to 13 d in the light receiving unit 13. Specifically, the spot SP12 is located at a location that does not straddle the light receiving elements 13a and 13b. In this case, since signals are not output from all the light receiving elements 13a to 13d of the light receiving unit 13, the video ASIC 3 cannot appropriately detect the optical axis deviation based on the light receiving signal Sd1 from the light receiving unit 13. . Specifically, since no signal is output from the light receiving elements 13a and 13b in the upper half of the light receiving unit 13, the video ASIC 3 cannot appropriately detect the optical axis shift in the vertical direction. 3B, when the spot SP12 is not formed at a position across all of the light receiving elements 13a to 13d (in other words, when the center C1 of the light receiving unit 13 is not included in the range of the spot SP12). Corresponds to the case where the beam is irradiated outside the detectable range of the light receiving unit 13.

  Here, when a configuration is adopted in which the size of the spot formed on the light receiving unit 13 is increased (for example, a pinhole 12a1 having a relatively large size is used), the beam is within the detectable range of the light receiving unit 13. It becomes easy to be irradiated. That is, it is possible to ensure a wide detection range for optical axis deviation. However, since the detection accuracy of the optical axis shift is affected by the size of the spot formed on the light receiving unit 13, the detection accuracy of the optical axis shift tends to decrease when the spot size is increased as described above. That is, in order to ensure the detection accuracy of the optical axis deviation, it is desirable to make the size of the spot formed on the light receiving unit 13 as small as possible. As described above, it can be said that the detection accuracy of the optical axis deviation and the detection range are in a trade-off relationship.

  In the first embodiment, from the viewpoint of ensuring the detection accuracy of the optical axis deviation, a configuration is adopted in which the size of the spot formed on the light receiving unit 13 is as small as possible (for example, the pinhole 12a1 having a relatively small size is used). adopt). When the spot size is reduced in this way, the beam irradiation position is likely to be out of the detectable range of the light receiving unit 13. To cope with this, in the first embodiment, the beam is out of the detectable range of the light receiving unit 13. When the beam is irradiated, the pinhole portion 12 a is moved in the direction approaching the light receiving portion 13 so that the beam is irradiated within the detectable range of the light receiving portion 13. In this way, a wide detection range for optical axis deviation is ensured.

  The control method according to the first embodiment will be specifically described with reference to FIG. 4A and 4B show a state in which the beam that has passed through the pinhole 12a1 of the pinhole portion 12a is incident on the light receiving portion 13 on the left side, and the beam that has passed through the pinhole 12a1 on the right side. Shows the spots SP12 and SP13 formed on the light receiving unit 13. FIG. 4A is a diagram similar to FIG. That is, the case where the beam is irradiated outside the detectable range of the light receiving unit 13 is shown.

  In the first embodiment, as shown in FIG. 4A, when the beam is irradiated outside the detectable range of the light receiving unit 13, the video ASIC 3 controls the drive unit 20a to change the pinhole unit 12a. It moves in the direction approaching the light receiving unit 13 (see arrow A3 in FIG. 4B). This makes it possible to form the spot SP13 at a position across all of the light receiving elements 13a to 13d in the light receiving portion 13 (in FIG. 4B, the pinhole portion 12a is not moved for comparison). The spot SP12 formed at this time is indicated by a broken line). That is, it is possible to irradiate the beam within the detectable range of the light receiving unit 13. As a result, since the signals are output from all of the light receiving elements 13a to 13d, the video ASIC 3 can appropriately detect the optical axis deviation based on the light receiving signal Sd1 from the light receiving unit 13.

  In one example, the drive unit 20a is configured to change the distance between the pinhole unit 12a and the light receiving unit 13 in two or more steps. That is, the drive part 20a is comprised so that the pinhole part 12a can be moved to two or more positions in steps. In this example, the video ASIC 3 moves the pinhole portion 12a stepwise in a direction approaching the light receiving portion 13 when the beam is irradiated outside the detectable range of the light receiving portion 13. Specifically, the video ASIC 3 moves the pinhole portion 12a closer to the light receiving portion 13 until the beam is irradiated within the detectable range of the light receiving portion 13 based on the light receiving signal Sd1 from the light receiving portion 13. Move in steps.

  In another example, the drive unit 20a is configured to continuously change the distance between the pinhole unit 12a and the light receiving unit 13 within a certain range. That is, the drive part 20a is comprised so that the pinhole part 12a can be moved continuously. In this example, the video ASIC 3 continuously moves the pinhole portion 12 a in the direction approaching the light receiving unit 13 when the beam is irradiated outside the detectable range of the light receiving unit 13. Specifically, the video ASIC 3 moves the pinhole portion 12a closer to the light receiving portion 13 until the beam is irradiated within the detectable range of the light receiving portion 13 based on the light receiving signal Sd1 from the light receiving portion 13. To move continuously. Thus, according to the structure which can move the pinhole part 12a steplessly, it can always detect at a distance with high sensitivity.

  The shortest distance between the pinhole portion 12a and the light receiving portion 13 set by the driving portion 20a is the distance between the pinhole portion 12a and the light receiving portion 13 that can appropriately detect the assumed maximum optical axis deviation. It is good to set.

  Here, with reference to FIG. 5, the reason why the beam can be irradiated within the detectable range of the light receiving unit 13 when the pinhole unit 12 a is moved in the direction approaching the light receiving unit 13 will be described. FIG. 5 shows a state in which the beam that has passed through the pinhole 12a1 of the pinhole portion 12a is incident on the light receiving portion 13 on the left side, and is formed on the light receiving portion 13 by the beam that has passed through the pinhole 12a1 on the right side. The spot SP is shown. Here, a case where the optical axis is shifted only in the vertical direction is illustrated.

  As shown in FIG. 5, the distance y between the center C2 of the spot SP formed on the light receiving part 13 by the beam and the center C1 of the light receiving part 13 is the distance d between the pinhole part 12a and the light receiving part 13, and the pin It is expressed by “y = d · tan θ” by using an emission angle θ of the beam from the hole portion 12a (corresponding to an angle corresponding to an optical axis deviation). According to this equation, it can be seen that the distance y between the center C2 of the spot SP and the center C1 of the light receiving portion 13 becomes shorter as the distance d between the pinhole portion 12a and the light receiving portion 13 becomes shorter. Therefore, when the pinhole portion 12a is moved in the direction approaching the light receiving portion 13, it is possible to irradiate the beam irradiated outside the detectable range of the light receiving portion 13 within the detectable range of the light receiving portion 13. .

  According to the first embodiment described above, by moving the pinhole portion 12a in the direction approaching the light receiving portion 13, the beam irradiated outside the detectable range of the light receiving portion 13 is appropriately within the detectable range. Can be irradiated. Therefore, according to the first embodiment, it is possible to ensure a wide detection range for the optical axis deviation. Further, in the first embodiment, as described above, since the configuration in which the size of the spot formed on the light receiving unit 13 is as small as possible is adopted, it is possible to ensure the detection accuracy of the optical axis deviation. From the above, according to the first embodiment, it is possible to appropriately ensure both the detection accuracy and the detection range of the optical axis deviation.

  By the way, as a configuration capable of ensuring both the detection accuracy and the detection range of the optical axis deviation, two light receiving portions on which two small and large pin holes are formed and the beams emitted from the two pin holes are incident (Hereinafter, referred to as “composition of a comparative example”). However, in the configuration of the comparative example, the accuracy variation between the two light receiving units may be a problem. On the other hand, according to the first embodiment, since only one light receiving portion 13 is used, such a variation in accuracy between the light receiving portions does not cause a problem. Further, according to the first embodiment, the space and cost for one light receiving portion can be reduced as compared with the configuration of the comparative example (however, the cost for the driving portion 20a is increased).

  In the above example, the pinhole portion 12a is moved in the direction approaching the light receiving portion 13. However, in another example, the light receiving portion 13 is moved closer to the pinhole portion 12a without moving the pinhole portion 12a. It may be moved in the direction. In still another example, both the light receiving unit 13 and the pinhole unit 12a may be moved so that the distance between the light receiving unit 13 and the pinhole unit 12a is shortened.

[Second Embodiment]
Next, a second embodiment will be described. In the first embodiment, when the beam is irradiated outside the detectable range of the light receiving portion 13, the pinhole portion 12a is moved in the direction approaching the light receiving portion 13, that is, the pinhole portion 12a and the light receiving portion 13 Was changing the distance. On the other hand, in the second embodiment, the size of the pinhole used to form a spot on the light receiving unit 13 is changed when the beam is irradiated outside the detectable range of the light receiving unit 13. Specifically, in the second embodiment, a pin used to form a spot on the light receiving unit 13 when an optical axis shift occurs such that a beam is irradiated outside the detectable range of the light receiving unit 13. Increase the size of the hole.

  In the following, the configuration and control different from the first embodiment will be mainly described, and the description of the same configuration and control as in the first embodiment will be omitted as appropriate. That is, the configuration and control not particularly described below are the same as those in the first embodiment.

  FIG. 6 shows a configuration of a projection apparatus 1b according to the second embodiment. The projection apparatus 1b according to the second embodiment is different from the projection apparatus 1a according to the first embodiment in that a laser light source unit 9b and a drive unit 20b are provided instead of the laser light source unit 9a and the drive unit 20a. The laser light source unit 9b according to the second embodiment is different from the laser light source unit 9a according to the first embodiment in that it has a pinhole portion 12b instead of the pinhole portion 12a.

  FIG. 7 shows a plan view of the pinhole portion 12b according to the second embodiment. Specifically, the figure which observed the pinhole part 12b from the arrow A5 direction in FIG. 6 is shown. As shown in FIG. 7, the pinhole portion 12b is formed with two pinholes 12b1 and 12b2 as through holes. The size (diameter) of the pinhole 12b1 is smaller than the size (diameter) of the pinhole 12b2. Further, the pinhole 12b1 and the pinhole 12b2 are arranged apart from the diameter of the beam irradiated to the pinhole portion 12b. The pinhole portion 12b corresponds to an example of the “first pinhole portion” in the present invention, the pinhole 12b1 corresponds to an example of the “first hole” in the present invention, and the pinhole 12b2 corresponds to the present invention. Corresponds to an example of “second hole” in FIG.

  Returning to FIG. As shown by an arrow A4 in FIG. 6, the drive unit 20b is substantially perpendicular to the beam traveling direction from the beam splitter 93 to the light receiving unit 13, and the pinholes 12b1 and 12b2 are arranged in the pinhole part 12b. The pinhole portion 12b is configured to be movable in a direction along the vertical direction. Specifically, the driving unit 20b determines the position of the pinhole portion 12b, the position where the beam transmitted through the beam splitter 93 is incident only on the pinhole 12b1, and the beam transmitted through the beam splitter 93 only in the pinhole 12b2. It is comprised so that it can switch to the position which injects into. That is, the drive unit 20b is configured to be able to switch the position of the pinhole portion 12b to two locations. By driving the pinhole portion 12b by the driving portion 20b, the beam that has passed through the beam splitter 93 passes through the pinhole 12b1 and enters the light receiving portion 13, or passes through the pinhole 12b2 and receives the light receiving portion 13. It is possible to switch between the incident light and the incident light. The drive unit 20b is controlled by the video ASIC 3. The driving unit 20b (which may include the video ASIC 3) corresponds to an example of “driving unit” in the present invention.

  FIG. 8 is a diagram for specifically explaining the control method according to the second embodiment. 8A to 8C show a state in which the beam that has passed through the pinhole portion 12b is incident on the light receiving portion 13 on the left side, and the light receiving portion by the beam that has passed through the pinhole portion 12b on the right side. 13 shows spots SP21, SP22 and SP23 formed on the surface. FIG. 8A shows a diagram when the optical axis deviation is small, and FIGS. 8B and 8C show diagrams when the optical axis deviation is large.

  Basically, the video ASIC 3 is driven in a place where the beam transmitted through the beam splitter 93 is incident on the pinhole 12b1 (smaller pinhole) from the viewpoint of ensuring the detection accuracy of the optical axis deviation. The pinhole part 12b is positioned by the part 20b. That is, the video ASIC 3 sets the pinhole portion 12b at a position where the beam transmitted through the beam splitter 93 enters the pinhole 12b1 as an initial setting when detecting the optical axis deviation. When the pinhole portion 12b is set at such a position, when the optical axis deviation is small, as shown in FIG. 8A, the spot SP21 is located at a position across all of the light receiving elements 13a to 13d in the light receiving portion 13. It is formed. That is, the beam that has passed through the pinhole 12 b 1 is irradiated within the detectable range of the light receiving unit 13. However, when the optical axis deviation is large, as shown in FIG. 8B, the spot SP <b> 22 is not formed at a position across all of the light receiving elements 13 a to 13 d in the light receiving unit 13. That is, the beam that has passed through the pinhole 12 b 1 is irradiated outside the detectable range of the light receiving unit 13.

  In the second embodiment, as shown in FIG. 8B, when the beam is irradiated outside the detectable range of the light receiving unit 13, the video ASIC 3 transmits the beam splitter 93 by controlling the driving unit 20b. The pinhole portion 12b is moved from a place where the beam is incident on the pinhole 12b1 to a place where the beam transmitted through the beam splitter 93 is incident on the pinhole 12b2 (arrow A6 in FIG. 8C). reference). That is, the pinhole used for forming a spot in the light receiving unit 13 is switched from the pinhole 12b1 to the pinhole 12b2. That is, the size of the pinhole used for forming a spot in the light receiving unit 13 is increased. Thereby, a spot SP23 larger than the case where the pinhole 12b1 is used is formed in the light receiving portion 13 (in FIG. 8C, for comparison, the spot SP22 formed when the pinhole 12b1 is used is changed. (Shown in broken lines). As a result, the spot SP23 can be formed at a position across all of the light receiving elements 13a to 13d in the light receiving unit 13. That is, it is possible to irradiate the beam within the detectable range of the light receiving unit 13. Therefore, since signals are output from all of the light receiving elements 13a to 13d, the video ASIC 3 can appropriately detect the optical axis deviation based on the light receiving signal Sd1 from the light receiving unit 13.

  The pinhole 12b1 is preferably set to a size that ensures the detection accuracy of the optical axis deviation, and the pinhole 12b2 is preferably set to a size that can appropriately detect the assumed maximum optical axis deviation.

  According to the second embodiment described above, it is possible to appropriately ensure both the detection accuracy and the detection range of the optical axis deviation as in the first embodiment.

[Third embodiment]
Next, a third embodiment will be described. In the third embodiment as well, in the same way as in the second embodiment, in order to form a spot on the light receiving unit 13 when an optical axis shift occurs such that the beam is irradiated outside the detectable range of the light receiving unit 13. Change the size of the pinhole used for. However, the third embodiment is different from the second embodiment in the method for changing the pinhole size.

  In the following, the configuration and control different from those in the first and second embodiments will be mainly described, and description of the same configuration and control as in the first and second embodiments will be omitted as appropriate. That is, the configuration and control not particularly described below are the same as those in the first and second embodiments.

  FIG. 9 shows a configuration of a projection apparatus 1c according to the third embodiment. The projection apparatus 1c according to the third example is different from the projection apparatus 1a according to the first example in that a laser light source unit 9c and a drive unit 20c are provided instead of the laser light source unit 9a and the drive unit 20a. The laser light source unit 9c according to the third embodiment is different from the laser light source unit 9a according to the first embodiment in that it has two pinhole portions 12c1 and 12c2 instead of the pinhole portion 12a.

  FIG. 10 is a plan view of the pinhole portions 12c1 and 12c2 according to the third embodiment. Specifically, the figure which observed the pinhole parts 12c1 and 12c2 from the arrow A8 direction in FIG. 9 is shown. As shown in FIG. 10A, a pinhole 12c11 as a through hole is formed in the pinhole portion 12c1, and as shown in FIG. 10B, a pin as a through hole is formed in the pinhole portion 12c2. A hole 12c21 is formed. The size (diameter) of the pinhole 12c11 is smaller than the size (diameter) of the pinhole 12c21.

  The pinhole portion 12c1 corresponds to an example of the “first pinhole portion” in the present invention, and the pinhole portion 12c2 corresponds to an example of the “second pinhole portion” in the present invention. The pinhole 12c11 formed in the pinhole portion 12c1 corresponds to an example of the “first hole” in the present invention, and the pinhole 12c21 formed in the pinhole portion 12c2 is the “second hole” in the present invention. It corresponds to an example.

  Returning to FIG. As shown in FIG. 9, the pinhole portion 12 c 1 and the pinhole portion 12 c 2 are arranged adjacent to each other in the direction along the beam traveling direction from the beam splitter 93 to the light receiving portion 13. Moreover, the pinhole part 12c1 is arrange | positioned with respect to the pinhole part 12c2 at the light-receiving part 13 side.

  The drive unit 20c is configured to be able to move the pinhole portion 12c1 in a direction substantially perpendicular to the beam traveling direction from the beam splitter 93 to the light receiving unit 13 as indicated by an arrow A7 in FIG. Specifically, the driving unit 20c determines the position of the pinhole part 12c1, the position where the beam that has passed through the beam splitter 93 and passed through the pinhole 12c21 of the pinhole part 12c2 is incident on the pinhole 12c11, and the beam A position where the beam that has passed through the splitter 93 and passed through the pinhole 12c21 of the pinhole portion 12c2 is not irradiated to the pinhole portion 12c1 (specifically, the beam that has passed through the pinhole 12c21 does not pass through the pinhole 12c11 and The position is such that it is not blocked by the hole portion 12c1. That is, the drive part 20c is comprised so that the position of the pinhole part 12c1 can be switched to two places. By driving the pinhole portion 12c1 by the driving portion 20c, the beam transmitted through the beam splitter 93 is sequentially passed through the pinhole 12c21 of the pinhole portion 12c2 and the pinhole 12c11 of the pinhole portion 12c1 to the light receiving portion 13. It is possible to switch between making the light incident, or allowing only the pinhole 12c21 of the pinhole portion 12c2 to pass through and incident on the light receiving portion 13. The drive unit 20c is controlled by the video ASIC 3. The drive unit 20c (which may include the video ASIC 3) corresponds to an example of “drive unit” in the present invention.

  FIG. 11 is a diagram for specifically explaining the control method according to the third embodiment. FIGS. 11A to 11C show how the beam that has passed through both the pinhole portions 12c1 and 12c2 or the beam that has passed through only the pinhole portion 12c2 is incident on the light receiving portion 13 on the left side. On the right side, spots SP31, SP32, and SP33 formed on the light receiving unit 13 by the beam are shown. FIG. 11A shows a diagram when the optical axis deviation is small, and FIGS. 11B and 11C show diagrams when the optical axis deviation is large.

  Basically, the video ASIC 3 positions the pinhole portion 12c1 by the drive unit 20c in a place where the beam that has passed through the beam splitter 93 and passed through the pinhole 12c21 of the pinhole portion 12c2 enters the pinhole 12c11. Let me. That is, the video ASIC 3 sets the pinhole portion 12c1 at a position where the beam that has passed through the pinhole 12c21 of the pinhole portion 12c2 enters the pinhole 12c11 as an initial setting when detecting the optical axis deviation. deep. This is because a spot is formed on the light receiving unit 13 by the beam that has passed through the pinhole 12c11 having a small size from the viewpoint of ensuring the detection accuracy of the optical axis deviation.

  When the pinhole portion 12c1 is set at the position as described above, when the optical axis deviation is small, as shown in FIG. 11A, the spot SP31 is located at a position across all of the light receiving elements 13a to 13d in the light receiving portion 13. Is formed. That is, the beam that has passed through the pinhole 12 c 11 is irradiated within the detectable range of the light receiving unit 13. However, when the optical axis deviation is large, the spot SP32 is not formed at a position across all of the light receiving elements 13a to 13d in the light receiving unit 13, as shown in FIG. That is, the beam that has passed through the pinhole 12 c 11 is irradiated outside the detectable range of the light receiving unit 13.

  In the third embodiment, when the beam is irradiated outside the detectable range of the light receiving unit 13 as shown in FIG. 11B, the video ASIC 3 controls the drive unit 20c, thereby controlling the pinhole unit 12c2. The pinhole portion 12c1 is moved from a location where the beam that has passed through the pinhole 12c21 enters the pinhole 12c11 to a location where the beam that has passed through the pinhole 12c21 of the pinhole portion 12c2 is not irradiated to the pinhole portion 12c1. (See arrow A9 in FIG. 11C). That is, the pinhole used for forming a spot in the light receiving unit 13 is switched from the pinhole 12c11 to the pinhole 12c21. That is, the size of the pinhole used for forming a spot in the light receiving unit 13 is increased. Thereby, a spot SP33 larger than the case where the pinhole 12c11 is used is formed in the light receiving portion 13 (in FIG. 11C, for comparison, the spot SP32 formed when the pinhole 12c11 is used is used. (Shown in broken lines). As a result, the spot SP33 can be formed at a position across all of the light receiving elements 13a to 13d in the light receiving unit 13. That is, it is possible to irradiate the beam within the detectable range of the light receiving unit 13. Therefore, since signals are output from all of the light receiving elements 13a to 13d, the video ASIC 3 can appropriately detect the optical axis deviation based on the light receiving signal Sd1 from the light receiving unit 13.

  In addition, the pinhole 12c11 of the pinhole part 12c1 is set to a size that ensures the detection accuracy of the optical axis deviation, and the pinhole 12c21 of the pinhole part 12c2 appropriately sets the assumed maximum optical axis deviation. The size should be set so that it can be detected.

  According to the third embodiment described above, it is possible to appropriately ensure both the detection accuracy and the detection range of the optical axis deviation as in the first embodiment.

[Modification]
The method of changing the size of the pinhole when the beam is irradiated outside the detectable range of the light receiving unit 13 is not limited to the method shown in the second and third embodiments. For example, the pinhole size may be changed using a camera squeezing mechanism or a liquid crystal pattern. According to this example, the size of the pinhole can be changed by using one pinhole portion having one pinhole. Therefore, it is not necessary to use the two pinholes 12b1 and 12b2 as shown in the second embodiment, and it is not necessary to use the two pinhole portions 12c1 and 12c2 as shown in the third embodiment.

1 Projector 3 Video ASIC
7 Laser driver ASIC
8 MEMS mirror control unit 9 Laser light source unit 10 MEMS mirror 12a, 12b, 12c1, 12c2 Pinhole part 12a1, 12b1, 12b2, 12c11, 12c21 Pinhole 20a, 20b, 20c Drive part 13 Light receiving part 93 Beam splitter LD1 Red laser LD2 Blue laser LD3 Green laser

Claims (5)

A combining element for combining the first beam and the second beam;
A first pinhole portion having a first hole into which the beam emitted from the combining element is incident;
A light receiving element that receives a beam emitted from the combining element through the first hole and outputs a light receiving signal corresponding to a light receiving position of the beam;
Driving means for moving the first pinhole portion and / or the light receiving element;
With
The driving means moves the first pinhole portion and / or the light receiving element so that the beam is irradiated within the predetermined range when the beam is irradiated outside the predetermined range of the light receiving element. A light source unit characterized by   The driving means has a short distance between the first pinhole portion and the light receiving element when a beam emitted from the combining element and passed through the first hole is irradiated outside a predetermined range of the light receiving element. The light source unit according to claim 1, wherein the first pinhole portion and / or the light receiving element are moved. A second pinhole portion having a second hole larger than the first hole;
The beam emitted from the combining element is incident on the first hole through the second hole,
The driving means emits the beam into the first pinhole portion when the beam emitted from the combining element and passing through the first hole and the second hole is irradiated outside a predetermined range of the light receiving element. The light source unit according to claim 1, wherein the first pinhole portion is moved to a position where the light source is not used. The first pinhole portion has not only the first hole but also a second hole larger than the first hole,
The driving means emits the beam emitted from the combining element and passes through the second hole when the beam that has passed through the first hole is irradiated outside the predetermined range of the light receiving element. The light source unit according to claim 1, wherein the first pinhole portion is moved to a position to be moved. Control means for controlling light emission of the first beam and the second beam;
The control means emits one of the first beam and the second beam,
The light receiving element receives one of the first beam and the second beam emitted by the control means, and outputs a light receiving signal corresponding to a light receiving position of the beam. The light source unit according to claim 2.

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