JP2012226303A - Light source unit and headup display - Google Patents

Abstract

PROBLEM TO BE SOLVED: To properly suppress an excessive pixel bright spot in configuration using a micro-lens array.SOLUTION: An optical element comprises a first and a second micro-lens array parts in which a plurality of micro-lenses is respectively arranged. The first and the second micro-lens array parts are oppositely arranged at a position spaced from each other by distance which is longer than focal distance of a micro-lens arranged on the first micro-lens array part. The first micro-lens array part is arranged at a light incident side for the second micro-lens array part. Also, the optical element is configured such that an interval between the micro-lenses arranged in the first micro-lens array part is narrower than an interval between the micro-lenses arranged in the second micro-lens array part. By using the optical element, occurrence of an excessive pixel bright spot can be properly suppressed.

Description

  The present invention relates to an optical element using a microlens array.

  Conventionally, a technique of applying a transmissive screen using a microlens array to a head-up display or a laser projector has been proposed. When such a transmission type screen is used, there is a merit that the influence of speckle noise can be suppressed as compared with the case where a diffusion plate is used. For example, Patent Document 1 proposes an image forming apparatus including a laser projector that uses a laser beam as a light source and projects an image formed by an array of a plurality of pixels, and a microlens array in which a plurality of microlenses are arrayed. Yes. When a microlens array is used, incident light can be appropriately dispersed and a necessary diffusion angle can be freely designed.

  On the other hand, for example, Patent Documents 2 and 3 and Non-Patent Document 1 propose that a screen is configured using two microlens arrays or two diffraction gratings. In particular, in Non-Patent Document 1, there is a tendency that uneven brightness occurs when only one microlens array is used. However, such uneven brightness occurs when two microlens arrays are used. It is described that can be suppressed.

JP 2010-145745 A JP-A-8-16656 Special table 2007-523369 gazette

H. Urey and K. D. Powell, “Microlens-array-based exit-pupil expander for full-color displays”, APPLIED OPTICS Vol.44, No.23, p.4930-4936

  By the way, for example, when a microlens array is applied to a laser scan type light source, an image (hereinafter referred to as “intermediate image”) is formed in which the focal point of each microlens included in the microlens array is a pixel position. . In this case, since the light source is a laser, the condensing characteristic at the focal point of the microlens array is high. Therefore, in some cases, pixels formed by each microlens (that is, pixels corresponding to the focal point of the microlens) are separated on the intermediate image plane by the microlens array. In other words, a bright portion and a dark portion may appear prominently on the intermediate image plane. Therefore, when the intermediate image formed by the microlens array is enlarged and displayed, the pixels formed by each microlens of the microlens array are referred to as excessive luminescent spots (hereinafter referred to as “pixel luminescent spots”). It may stand out. Patent Documents 1 to 3 and Non-Patent Document 1 described above do not describe a technique for suppressing such excessive pixel bright spots.

  Examples of the problem to be solved by the present invention are as described above. An object of the present invention is to provide an optical element, a head-up display, and a light source unit that can appropriately suppress excessive pixel bright spots in a configuration using a microlens array.

According to the first aspect of the present invention, an optical element having a first microlens array part and a second microlens array part in which a plurality of microlenses are arranged, the first microlens array part and the second microlens array part. The lens array unit is disposed opposite to each other at positions separated from each other by a distance longer than the focal length of the microlens arranged in the first microlens array unit, and the microarray arranged in the first microlens array unit. An interval between the lenses is configured to be narrower than an interval between the microlenses arranged in the second microlens array unit, and the first microlens array unit emits light with respect to the second microlens array unit. disposed on the incident side has a first micro-lens array section on one surface, the second microlens a Having Lee portion on the other side.

According to a fifth aspect of the present invention, a head-up display includes the optical element according to any one of the first to fourth aspects, and an image formed by the optical element is visually recognized as a virtual image from the position of the user's eyes. Let

In the invention according to claim 6 , the light source unit includes a light source, a first microlens array in which a plurality of microlenses are arranged at a predetermined interval, and a plurality of microlenses arranged at an interval wider than the predetermined interval. A second microlens array, wherein the second microlens array is disposed at a position separated by a distance longer than a focal length of a macro lens disposed in the first microlens array, One microlens array is disposed on an incident side of light emitted from the light source with respect to the second microlens array , the first microlens array is formed on one surface of an optical element, and the second The microlens array is formed on the other surface of the optical element .

The structure of the image display apparatus which concerns on a present Example is shown. The perspective view of the screen which concerns on a present Example is shown. The structure of the 1st and 2nd micro lens array part which concerns on a present Example is shown. The figure for demonstrating the excessive pixel luminescent spot which may be produced by the general micro lens array part is shown. The figure for demonstrating the effect | action and effect of the screen which concerns on a present Example is shown. The concrete structure of the screen which concerns on the modification 1 is shown. The specific structure of the screen which concerns on the other example of the modification 1 is shown. The specific structure of the screen which concerns on the modification 2 is shown. The concrete structure of the screen which concerns on the modification 3 is shown. The specific structure of the screen which concerns on the modification 4 is shown. The specific structure of the screen which concerns on the modification 5 is shown. The specific structure of the screen which concerns on the other example of the modification 5 is shown. The specific structure of the screen which concerns on the modification 6 is shown. The specific structure of the screen which concerns on the other example of the modification 6 is shown. The specific structure of the screen which concerns on the modification 7 is shown. The specific structure of the screen which concerns on the other example of the modification 7 is shown. The specific structure of the screen which concerns on the modification 8 is shown. The specific structure of the screen which concerns on the other example of the modification 8 is shown.

  In one aspect of the present invention, an optical element having a first microlens array section and a second microlens array section in which a plurality of microlenses are arranged, the first microlens array section and the second microlens. The array unit is arranged to face each other at positions separated from each other by a distance longer than the focal length of the microlens arranged in the first microlens array unit, and the microlens arranged in the first microlens array unit The interval between each other is configured to be narrower than the interval between the microlenses arranged in the second microlens array unit, and the first microlens array unit transmits light to the second microlens array unit. It is arranged on the incident side.

  The optical element includes first and second microlens array portions each having a plurality of microlenses arranged therein. In other words, the optical element corresponds to a screen. The first and second microlens array units are arranged to face each other at positions separated from each other by a distance longer than the focal length of the microlenses arranged in the first microlens array unit. The first microlens array part is disposed on the light incident side with respect to the second microlens array part. The first and second microlens array units are configured such that the interval between the microlenses arranged in the first microlens array unit is narrower than the interval between the microlenses arranged in the second microlens array unit. ing. That is, the lens pitch of the microlenses of the first microlens array portion is configured to be smaller than the lens pitch of the microlenses of the second microlens array portion. In other words, the lens diameter of one microlens of the first microlens array unit is configured to be smaller than the lens diameter of one microlens of the second microlens array unit.

  According to the optical element described above, the light condensed by the two or more microlenses of the first microlens array unit is incident on one microlens of the second microlens array unit. Thereby, two or more pixels formed by two or more microlenses of the first microlens array unit are aggregated by one microlens of the second microlens array unit to form one pixel. That is, two or more pixels formed by the first microlens array unit are aggregated as pixels having a size larger than the two or more pixels by one microlens of the second microlens array unit. Thereby, pixel luminescent spots can be made inconspicuous. Therefore, according to the optical element, it is possible to appropriately suppress the occurrence of excessive pixel bright spots even when the intermediate image by the second microlens array unit is enlarged and displayed.

  In one aspect of the optical element described above, light collected by two or more microlenses of the first microlens array unit is collected by being incident on one microlens of the second microlens array unit. As described above, the interval between the microlenses arranged in the first microlens array portion and the second microlens array portion is set.

  In the optical element, the first light is collected so that the light collected by the two or more microlenses of the first microlens array unit is collected by being incident on one microlens of the second microlens array unit. An interval between the microlenses arranged in the microlens array unit and the second microlens array unit is set. Thereby, generation | occurrence | production of an excessive pixel luminescent spot can be suppressed appropriately.

  Preferably, in the above optical element, the first microlens array unit forms one or more pixels by distributing one pixel corresponding to incident light by the two or more microlenses, The second microlens array unit forms one pixel by aggregating the two or more adjacent pixels distributed by the first microlens array unit with the one microlens.

  In another aspect of the optical element described above, the interval between the microlenses arranged in the first microlens array unit is “1” which is the interval between the microlenses arranged in the second microlens array unit. / 2 "or less. Thereby, generation | occurrence | production of an excessive pixel luminescent spot can be suppressed effectively.

  Preferably, the interval between the microlenses is an interval between centroids of adjacent microlenses. In other words, the interval between microlenses is the distance between the centers of adjacent microlenses.

  Preferably, in the optical element, the first microlens array unit and the second microlens array unit are 1.5 times or more the focal length of the microlens arranged in the first microlens array unit, and Oppositely arranged at a position separated by a distance of three times or less.

  In another aspect of the optical element, each of the plurality of microlenses is configured with a polygonal lens outline in a plan view, and the first microlens array unit and the second microlens array unit The angle between the apex direction of the lens outline of the microlens arranged in the first microlens array part and the apex direction of the lens outline of the microlens arranged in the second microlens array part are shifted. Has been.

  In the above optical element, the first and second microlens array portions are arranged in a polygonal apex direction which is a lens contour of the microlens arranged in the first microlens array portion, and in the second microlens array portion. The angle difference from the apex direction of the polygonal shape that is the lens contour of the arranged microlenses is configured to a predetermined angle. That is, a plurality of microlenses are arranged in the first and second microlens array portions so that the polygonal shape that is the lens contour is rotated by a predetermined angle. According to the above-described optical element, unnecessary interference due to a polygonal image that may occur on the incident surface can be suppressed, and the influence of the positional deviation in the first and second microlens array portions can be appropriately suppressed. It becomes. Further, according to the optical element described above, since it is not necessary to strictly adjust the positions of the first and second microlens array portions, it is possible to produce the optical element easily and at low cost.

  In another aspect of the optical element described above, the polygonal shape is a regular hexagonal shape, the apex direction of the lens contour of the microlens arranged in the first microlens array portion, and the second microlens The angle difference from the apex direction of the lens contour of the microlens arranged in the array portion is approximately 30 degrees or approximately 90 degrees. According to this aspect, it is possible to effectively suppress the influence due to the displacement in the first and second microlens array portions.

  In another aspect of the above optical element, the polygonal shape is a square shape, the apex direction of the lens contour of the microlens arranged in the first microlens array portion, and the second microlens array The angle difference between the microlenses arranged in the section and the apex direction of the lens contour is approximately 45 degrees or approximately 135 degrees. According to this aspect, it is possible to effectively suppress the influence due to the displacement in the first and second microlens array portions.

  In another aspect of the optical element, each of the plurality of microlenses has a regular polygonal lens profile in plan view, and the first microlens array unit and the second microlens array unit are The angle between the apex direction of the lens outline of the microlens arranged in the first microlens array part and the apex direction of the lens outline of the microlens arranged in the second microlens array part, It is configured to be shifted by half of one interior angle included in the regular polygon shape. Also according to this aspect, it is possible to effectively suppress the influence of the positional deviation in the first and second microlens array portions.

  In another aspect of the above optical element, each of the first microlens array unit and the second microlens array unit includes the plurality of microlenses arranged at equal intervals, and the microlens is one microlens. Around the periphery, the microlenses arranged adjacent to the apex of the one microlens at a predetermined angle, and arranged in the first microlens array unit, and arranged in the second microlens array unit The microlens is configured to be shifted from the one microlens by half the predetermined angle. Also according to this aspect, it is possible to effectively suppress the influence due to the displacement in the first and second microlens array portions. In the optical element described above, it is preferable to mask so that light does not pass between the microlenses constituting the first and second microlens array portions.

  In another aspect of the above optical element, the optical element includes a first lens array having the first microlens array portion on one surface and a second lens array having the second microlens array portion on one surface. Is done. In other words, the first and second microlens array units are configured separately, and a plurality of microlenses are formed on one side of each.

  Preferably, the first microlens array part and the second microlens array part are formed on opposite surfaces of the first lens array and the second lens array, respectively. In other words, each of the first and second microlens array units has a plurality of microlenses formed on the opposing surfaces of the first and second microlens array units.

  Preferably, the first microlens array portion is formed on a surface of the first lens array that does not face the surface of the second lens array on which the second microlens array portion is formed. ing. In other words, one of the first and second microlens array units has a plurality of microlenses formed on opposing surfaces of the first and second microlens array units, and the first and second microlens array units. The other has a plurality of microlenses formed on the surface opposite to the opposing surface.

  Preferably, the first microlens array part and the second microlens array part are formed on surfaces of the first lens array and the second lens array that are not opposed to each other. In other words, each of the first and second microlens array units has a plurality of microlenses formed on the surface opposite to the opposing surface of the first and second microlens array units.

  In another aspect of the optical element, the first microlens array portion is provided on one surface, and the second microlens array portion is provided on the other surface. In other words, the first and second microlens array portions are integrally formed, and a plurality of microlenses are formed on opposite surfaces of the optical element. According to this aspect, since the two microlens array portions are integrally formed, it is only necessary to create one component on which the microlens array is formed, thereby further reducing the cost required for the optical element. It becomes possible.

  The above-described optical element can be suitably applied to a head-up display that visually recognizes an image as a virtual image from the position of the user's eyes.

  In another aspect of the present invention, the light source unit includes a light source, a first microlens array in which a plurality of microlenses are arranged at a predetermined interval, and a plurality of microlenses arranged at an interval wider than the predetermined interval. A second microlens array, wherein the second microlens array is disposed at a position separated by a distance longer than a focal length of a macro lens disposed in the first microlens array, The microlens array is disposed on the incident side of the light emitted from the light source with respect to the second microlens array. Even with the above light source unit, it is possible to appropriately suppress the occurrence of excessive pixel bright spots.

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

[Configuration of image display device]
FIG. 1 shows a configuration of an image display device to which an optical element according to the present embodiment is applied. As shown in FIG. 1, the image display device 1 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, a MEMS control unit 8, and a laser light source unit 9. A MEMS mirror 10 and a screen 11.

  The image display device 1 is applied to, for example, a head-up display. The head-up display is a device that visually recognizes an image as a virtual image from the position (eye point) of the driver's eyes.

  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 control unit 8 based on the image signal input from the image signal input unit 2 and the scanning position information Sc input from the MEMS mirror 10, and the ASIC (Application Specific Integrated). Circuit). 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 screen as 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 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 provided in a laser light source unit 9 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.

  The MEMS control unit 8 controls the MEMS mirror 10 based on a signal output from the timing controller 34. The MEMS 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 9 emits laser light to the MEMS mirror 10 based on the drive signal output from the laser driver ASIC 7.

  The MEMS mirror 10 as scanning means reflects the laser light emitted from the laser light source unit 9 toward the screen 11. In this way, the MEMS mirror 10 forms an image to be displayed on the screen 11. The MEMS mirror 10 moves so as to scan on the screen 11 under the control of the MEMS control unit 8 in order to display the image input to the image signal input unit 2, and the scanning position information ( For example, information such as a mirror angle) is output to the video ASIC 3.

  The screen 11 is an example of the “optical element” according to the present invention, is configured as a transmissive screen, and includes a microlens array unit (not shown) in which a plurality of microlenses are arranged. The microlens array unit appropriately disperses incident light. Specifically, the microlens array unit diffuses light at a diffusion angle corresponding to the curvature of the lens. The curvature of the lens in the microlens array unit is designed in advance according to the required diffusion angle. Details of the screen 11 will be described later.

  The image display device 1 actually displays an image corresponding to the light emitted from the screen 11 as described above, the light reflected by the reflecting mirror (combiner), the light enlarged by the magnifying element, and the like. It is visually recognized as a virtual image from the driver's eye position (eye point).

  Next, a detailed configuration of the laser light source unit 9 will be described. The laser light source unit 9 includes a case 91, a wavelength selective element 92, a collimator lens 93, a red laser LD1, a blue laser LD2, a green laser LD3, a monitor light receiving element (hereinafter simply referred to as “light receiving element”). 50).

  The case 91 is formed in a substantially box shape with resin or the like. In order to attach the green laser LD3, the case 91 is provided with a hole penetrating into the case 91 and a CAN attachment portion 91a having a concave cross section, and a surface perpendicular to the CAN attachment portion 91a. A hole penetrating inward is formed, and a collimator mounting portion 91b having a concave cross section is formed.

  The wavelength-selective element 92 as a combining element is constituted by, for example, a trichromatic prism, and is provided with a reflective surface 92a and a reflective surface 92b. The reflection surface 92a transmits the laser light emitted from the red laser LD1 toward the collimator lens 93, and reflects the laser light emitted from the blue laser LD2 toward the collimator lens 93. The reflecting surface 92b transmits most of the laser light emitted from the red laser LD1 and the blue laser LD2 toward the collimator lens 93 and reflects a part thereof toward the light receiving element 50. The reflection surface 92 b reflects most of the laser light emitted from the green laser LD 3 toward the collimator lens 93 and transmits part of the laser light toward the light receiving element 50. In this way, the emitted light from each laser is superimposed and incident on the collimator lens 93 and the light receiving element 50. The wavelength selective element 92 is provided in the vicinity of the collimator mounting portion 91b in the case 91.

  The collimator lens 93 converts the laser light incident from the wavelength selective element 92 into parallel light and emits it to the MEMS mirror 10. The collimator lens 93 is fixed to the collimator mounting portion 91b of the case 91 with a UV adhesive or the like. That is, the collimator lens 93 is provided after the synthesis element.

  A red laser LD1 as a laser light source emits red laser light. The red laser LD1 is fixed at a position that is coaxial with the wavelength selective element 92 and the collimator lens 93 in the case 91 while the semiconductor laser light source is in the chip state or the chip is mounted on a submount or the like. ing.

  A blue laser LD2 as a laser light source emits blue laser light. The blue laser LD2 is fixed at a position where the emitted laser light can be reflected toward the collimator lens 93 by the reflecting surface 92a while the semiconductor laser light source is in the chip state or the chip is mounted on the submount or the like. ing. The positions of the red laser LD1 and the blue laser LD2 may be switched.

  The green laser LD3 as a laser light source is in a state of being attached to the CAN package or in a state of being attached to the frame package, and emits green laser light. The green laser LD 3 has a semiconductor laser light source chip B that generates green laser light in a CAN package, and is fixed to a CAN mounting portion 91 a of the case 91.

  The light receiving element 50 receives a part of the laser light emitted from each laser light source. The light receiving element 50 is a photoelectric conversion element such as a photodetector, and supplies a detection signal Sd, which is an electrical signal corresponding to the amount of incident laser light, to the laser driver ASIC 7. Actually, at the time of power adjustment, one of red laser light, blue laser light, and green laser light is sequentially incident on the light receiving element 50, and the light receiving element 50 outputs a detection signal Sd corresponding to the amount of the laser light. To do. The laser driver ASIC 7 adjusts the power of the red laser LD1, the blue laser LD2, and the green laser LD3 according to the detection signal Sd.

  For example, when the power of the red laser LD1 is adjusted, the laser driver ASIC 7 operates only the red laser drive circuit 71, supplies a drive current to the red laser LD1, and emits red laser light from the red laser LD1. A part of the red laser light is received by the light receiving element 50, and a detection signal Sd corresponding to the amount of light is fed back to the laser driver ASIC7. The laser driver ASIC 7 adjusts the drive current supplied from the red laser drive circuit 71 to the red laser LD1 so that the light amount indicated by the detection signal Sd is an appropriate light amount. In this way, power adjustment is performed. The power adjustment of the blue laser LD2 and the power adjustment of the green laser LD3 are similarly performed.

  In addition, the above-described configuration part including at least the laser light source unit 9 and the screen 11 corresponds to an example of the “light source unit” according to the present invention.

[Screen structure]
Next, the configuration of the screen 11 according to the present embodiment will be specifically described. As described above, the screen 11 is an example of the “optical element” according to the present invention.

  FIG. 2 is a perspective view of the screen 11 according to the present embodiment. As shown in FIG. 2, the screen 11 includes a first microlens array part 11 a and a second microlens array part 11 b that are opposed to each other with a predetermined distance therebetween. The first microlens array part 11a and the second microlens array part 11b are each configured in a substantially disc shape. Further, each of the first microlens array unit 11a and the second microlens array unit 11b includes a plurality of microlenses 11aa and 11ba each having a regular hexagonal lens outline in a plan view in a lattice shape on one side. Is formed.

  Further, as shown in FIG. 2, the first microlens array unit 11a is disposed on the incident light side, and the second microlens array unit 11b is disposed on the outgoing light side. That is, the light first enters the first microlens array unit 11a, and the light emitted from the first microlens array unit 11a enters the second microlens array unit 11b.

  FIG. 3 is a diagram illustrating a specific configuration of the first microlens array unit 11a and the second microlens array unit 11b according to the present embodiment. FIG. 3A is a cross-sectional view of the first microlens array unit 11a and the second microlens array unit 11b taken along a plane perpendicular to the light traveling direction. Specifically, a cross-sectional view showing a part of the first microlens array portion 11a and the second microlens array portion 11b in an enlarged manner is shown. As shown in FIG. 3A, the first microlens array portion 11a and the second microlens array portion 11b are arranged to face each other so that the surfaces on which the plurality of microlenses 11aa and 11ba are formed face each other. That is, the first microlens array portion 11a and the second microlens array portion 11b are formed with a plurality of microlenses 11aa and 11ba on the opposing surfaces, respectively. Further, the first microlens array unit 11a and the second microlens array unit 11b are arranged to face each other at a position separated by a distance D. In the present embodiment, the first microlens array unit 11a and the second microlens array unit 11b are arranged at positions separated by a distance D that is at least longer than the focal length of the microlenses 11aa arranged in the first microlens array unit 11a. Place them facing each other. For example, the first microlens array unit 11a and the second microlens array unit 11b are arranged at positions separated by a distance D that is 1.5 to 3 times the focal length of the microlens 11aa.

  FIG. 3B is a plan view of the first microlens array unit 11a and the second microlens array unit 11b. Specifically, the top view which expanded and represented a part of 1st micro lens array part 11a and the 2nd micro lens array part 11b observed from the direction along the advancing direction of light is shown. As shown in FIG. 3B, each of the first microlens array unit 11a and the second microlens array unit 11b includes a plurality of microlenses 11aa and 11ba each having a regular hexagonal lens profile in plan view. Are arranged in a grid pattern. Specifically, the plurality of microlenses 11aa and 11ba are arranged with adjacent sides forming a regular hexagonal shape.

  In this embodiment, as shown in FIG. 3B, the lens pitch Pa of the microlenses 11aa arranged in the first microlens array section 11a and the microlenses 11ba arranged in the second microlens array section 11b. The first microlens array unit 11a and the second microlens array unit 11b are configured so that the lens pitch Pb is different. Specifically, the lens diameter Pa of the first microlens array unit 11a is smaller than the lens pitch Pb of the second microlens array unit 11b. In other words, the lens diameter of one microlens 11aa is one microlens. The first microlens array unit 11a and the second microlens array unit 11b are configured to be smaller than the lens diameter of 11ba. For example, the first microlens array unit 11a and the second microlens array unit 11b are configured so that the lens pitch Pa of the microlens 11aa is equal to or less than “½” of the lens pitch Pb of the microlens 11ba.

  The lens pitches Pa and Pb described above are, in other words, intervals between adjacent microlenses 11aa and 11ba arranged in the first microlens array unit 11a and the second microlens array unit 11b, and adjacent microlenses 11aa. , 11ba, which corresponds to the distance between the centers of gravity (that is, the distance between the centers). The same shall apply hereinafter.

[Screen effects / effects]
Next, the operation and effect of the screen 11 according to the above-described embodiment will be described.

  First, with reference to FIG. 4, an excessive pixel bright spot that may be generated by a general microlens array unit 200 will be described. FIG. 4A shows a diagram for explaining an intermediate image formed by a general microlens array unit 200. For example, when the microlens array unit 200 is applied to a laser scanning type light source, an intermediate image having a focal point of each microlens 200a of the microlens array unit 200 as a pixel position is a surface indicated by reference numeral 201 (a focal plane, hereinafter “ Called an "intermediate image plane"). In the example shown in FIG. 4A, the intermediate image is composed of pixels 202, 203, and 204 formed at the focal position of the microlens 200a. Such an interval between the pixels 202, 203, and 204 is equal to the lens pitch Pa of the microlens array unit 200.

  FIG. 4B shows a luminance intensity distribution on the intermediate image plane 201. Specifically, the luminance intensity distribution (generally Gaussian distribution) corresponding to the pixels 202, 203, and 204 formed on the intermediate image plane 201 is shown. As described above, when the microlens array unit 200 is applied to a laser scanning light source, since the light source is a laser, the light collection characteristic at the focal point of the microlens 200a is high. Therefore, as shown by an arrow 206 in FIG. 4B, the intermediate image plane 201 tends to be in a state where the pixels 202, 203, and 204 are separated. That is, in the intermediate image plane 201, a bright portion and a dark portion tend to appear remarkably. Therefore, for example, when the intermediate image is enlarged and displayed by a head-up display or the like, the pixels 202, 203, and 204 formed by the microlenses 200a of the microlens array unit 200 are conspicuous as excessive pixel bright spots. there is a possibility. Such a phenomenon can occur in the same manner even when two microlens array units 200 are used (the microlens array units 200 having substantially the same lens pitch are used).

  Next, with reference to FIG. 5, the effect | action and effect by the screen 11 which concern on a present Example are demonstrated. FIG. 5A is a diagram for explaining an intermediate image formed by the first microlens array unit 11a and the second microlens array unit 11b. In the present embodiment, since the lens pitch Pa of the first microlens array unit 11a is configured to be smaller than the lens pitch Pb of the second microlens array unit 11b, two or more micros in the first microlens array unit 11a. The light condensed by the lens 11aa enters one microlens 11ba of the second microlens array unit 11b. In the example shown in FIG. 5A, since the lens pitch Pa of the microlens 11aa is configured to be “1/3” of the lens pitch Pb of the microlens 11ba, the light condensed by the three microlenses 11aa The light enters one microlens 11ba.

  Here, a case where the lens pitch Pa in the first microlens array unit 11a is smaller than the pitch of pixels (hereinafter referred to as “original pixels”) corresponding to light input to the first microlens array unit 11a. Think. Specifically, an example in which light corresponding to one original pixel is incident on the three microlenses 11aa of the first microlens array unit 11a. In this example, light corresponding to one original pixel is distributed by the three microlenses 11aa of the first microlens array unit 11a, thereby forming three pixels (hereinafter, the first microlens array). Pixels distributed by the unit 11a are referred to as “distributed pixels”). Then, the three distribution pixels formed by the microlenses 11aa are aggregated by one microlens 11ba of the second microlens array unit 11b to form one pixel (hereinafter, the second microlens Pixels aggregated by the array unit 11b are referred to as “aggregated pixels”).

  In FIG. 5A, distribution pixels 212a to 212c, 213a to 213c, and 214a to 214c are formed as intermediate images on the intermediate image surface 211 located at the focal point of the micro lens 11aa of the first micro lens array unit 11a. Is shown. A pixel obtained by grouping three pixels in each of the distribution pixels 212a to 212c, 213a to 213c, and 214a to 214c corresponds to one original pixel. FIG. 5A shows an example in which aggregated pixels 216, 217, and 218 are formed as intermediate images on the intermediate image plane 215 located at the focal point of the microlens 11ba of the second microlens array unit 11b. . Each of the aggregated pixels 216, 217, and 218 corresponds to one original pixel.

  FIG. 5B shows a luminance intensity distribution on the intermediate image plane 211. Specifically, intensity distributions (generally Gaussian distribution) corresponding to the distribution pixels 212a to 212c, 213a to 213c, and 214a to 214c formed on the intermediate image plane 211 are shown. FIG. 5B shows that the distribution pixels 212a to 212c, 213a to 213c, and 214a to 214c are compared with the case where the general microlens array unit 200 as described above is used (see FIG. 4B). It can be seen that the separation is not noticeable. This is because the lens pitch Pa in the first microlens array unit 11a is configured to be smaller than the pitch of the original pixel. On the other hand, as indicated by an arrow 219 in FIG. 5B, it can be seen that there is a certain amount of difference between the high luminance portion and the low luminance portion. Such a difference may cause pixel luminescent spots to be noticeable.

  FIG. 5C shows a luminance intensity distribution on the intermediate image plane 215. Specifically, the luminance intensity distribution (generally Gaussian distribution) corresponding to the aggregated pixels 216, 217, and 218 formed on the intermediate image plane 215 is shown. From the arrow 220 in FIG. 5C, the intermediate image plane 215 is different from the above-described intermediate image plane 211 (see the arrow 219 in FIG. 5B) between the high luminance portion and the low luminance portion. It can be seen that is smaller. This is because the second micro lens array unit 11b having a lens pitch Pb sufficiently larger than the lens pitch Pa of the first micro lens array unit 11a is separated by a distance D longer than the focal length of the micro lens 11aa. This is thought to be due to the arrangement. That is, by configuring the first microlens array unit 11a and the second microlens array unit 11b in this way, a plurality of distribution pixels formed by the first microlens array unit 11a are converted into the second microlens array unit 11b. This is probably because the condensing pixels having a size larger than the distribution pixels are formed by aggregating by one microlens 11ba.

  From the above, according to the present embodiment, the pixel luminescent spots can be made inconspicuous appropriately. Therefore, according to the present embodiment, it is possible to appropriately suppress the occurrence of excessive pixel bright spots even when the intermediate image is enlarged and displayed by, for example, a head-up display.

  In this embodiment, the first microlens array unit 11a and the second microlens array unit 11b are opposed to each other at a position separated by a distance D that is at least longer than the focal length of the microlens 11aa of the first microlens array unit 11a. It is arranged. As a result, light incident on one microlens 11aa in the first microlens array unit 11a can be incident on a number of microlenses 11ba in the second microlens array unit 11b. Then, light can be condensed by each microlens 11ba of the second microlens array portion 11b to form a pixel. Thereby, since light can be appropriately dispersed, it is possible to form a uniform image with less unevenness (luminance unevenness).

  By the way, the above-mentioned Non-Patent Document 1 and the like describe that a screen (hereinafter referred to as a “screen according to a comparative example”) is configured using two microlens arrays. In the screen according to the comparative example, basically, the two microlens arrays are separated by the focal length of the microlens. In the configuration of such a comparative example, it is necessary to strictly adjust the positions of the two microlens arrays. Specifically, it is necessary to match the optical axes of the individual microlenses of the two microlens arrays. This is because if the distance between the two microlens arrays deviates from the focal length, or if the apex direction of the lens contour of the microlens deviates, the microlens may take in unwanted light, or the effect of the misalignment. This is because there may be a problem such as being visually recognized. For this reason, in the comparative example, there is a tendency that it takes time and cost to create the screen.

  In contrast, in the present embodiment, the first microlens array unit 11a and the second microlens array unit are located at positions separated by a distance D that is at least longer than the focal length of the microlens 11aa of the first microlens array unit 11a. 11b is arranged oppositely. According to the present embodiment, the resolution tends to be lower than the configuration of the comparative example in which two microlens arrays are arranged to be strictly separated from each other by the focal length of the microlens. The accuracy required when the lens array portion 11a and the second microlens array portion 11b are arranged to face each other can be reduced.

  Furthermore, according to the present embodiment, since it is not necessary to make the optical axes of the lenses coincide with each other by the above-described configuration, the influence can be reduced even if the incident angle changes. Therefore, it is possible to appropriately cope with a laser scanning light source having a relatively large angle of view. Therefore, there is no need to use a condenser lens arranged between the laser projector and the microlens array as described in Patent Document 1. Therefore, according to the present embodiment, the number of parts of the image display device 1 can be reduced.

  FIG. 5 shows an example in which the lens pitch Pa in the microlens 11aa of the first microlens array unit 11a is configured to be “1/3” of the lens pitch Pb in the microlens 11ba of the second microlens array unit 11b. However, this is not a limitation. For example, the lens pitch Pa in the first microlens array unit 11a may be configured to be “1/2”, “1/4”, “1/5”, or the like of the lens pitch Pb in the second microlens array unit 11b. good. In this case, two distribution pixels or four or more distribution pixels formed by the first microlens array unit 11a are collected into one pixel by the second microlens array unit 11b. Basically, the smaller the lens pitch Pa of the first microlens array unit 11a is smaller than the lens pitch Pb of the second microlens array unit 11b, the first microlens array unit 11a and the second microlens array unit. It becomes possible to suppress the influence by the position shift with 11b.

  Up to this point, an example has been shown in which “n” is an integer, and the lens pitch Pa in the first microlens array unit 11a is configured to be “1 / n” of the lens pitch Pb in the second microlens array unit 11b. In this case, the n pixels formed by the first microlens array unit 11a are integrated into one pixel by the second microlens array unit 11b.

  In the following, a case where a non-integer value is used as “n” will be considered. For example, when the lens pitch Pa in the first microlens array unit 11a is configured to be “2/5”, “2/7”, “3/7”, or the like of the lens pitch Pb in the second microlens array unit 11b. is there. In such a case, the light condensed by one microlens 11aa of the first microlens array part 11a tends to enter two adjacent microlenses 11ba in the second microlens array part 11b. In this case, it is influenced by the adjacent original pixels. However, by setting the above “n” to a larger value, that is, by making the lens pitch Pa of the first microlens array unit 11a smaller than the lens pitch Pb of the second microlens array unit 11b, Such influence can be reduced. Moreover, the influence by the position shift of the 1st micro lens array part 11a and the 2nd micro lens array part 11b can also be suppressed.

  Even when an integer value is used as “n”, the light collected by one microlens 11aa may enter two adjacent microlenses 11ba.

[Modification]
Hereinafter, modifications of the above-described embodiment will be described. Note that the description of the same configuration as the above-described embodiment will be omitted as appropriate. Further, a configuration that is not particularly described is the same as that of the above-described embodiment.

(Modification 1)
In the screen 11 according to the above-described embodiment, the first microlens array unit 11a and the second microlens array unit 11b are formed with a plurality of microlenses 11aa and 11ba on the opposing surfaces. On the other hand, in the screen according to the modified example 1, one of the first and second microlens array units has a plurality of microlenses formed on the opposing surfaces, and the other of the first and second microlens array units is A plurality of microlenses are formed on the surface opposite to the facing surface. In other words, in the screen according to the first modification, the first and second microlens array portions have a plurality of surfaces facing the same direction (specifically, a surface facing the incident light side or a surface facing the outgoing light side), A microlens is formed.

  FIG. 6 is a diagram illustrating a specific configuration of the screen 111 according to the first modification. FIG. 6 is a cross-sectional view of the first microlens array unit 111a and the second microlens array unit 111b of the screen 111 cut along a plane perpendicular to the light traveling direction. Specifically, a cross-sectional view showing a part of the first microlens array part 111a and the second microlens array part 111b in an enlarged manner is shown. It is assumed that light enters from the first microlens array unit 111a side.

  As shown in FIG. 6, in the first microlens array unit 111a, a plurality of microlenses 111aa are formed on the surface opposite to the opposing surface of the first microlens array unit 111a and the second microlens array unit 111b. ing. In the second microlens array unit 111b, a plurality of microlenses 111ba are formed on the opposing surfaces of the first microlens array unit 111a and the second microlens array unit 111b. That is, the first microlens array unit 111a and the second microlens array unit 111b include a surface of the first microlens array unit 111a in which the microlens 111aa is not formed and a second microlens array in which the microlens 111ba is formed. It is arranged so as to face the surface of the part 111b.

  In addition, the first microlens array unit 111a and the second microlens array unit 111b are disposed at positions separated by a distance D1 that is at least longer than the focal length of the microlens 111aa of the first microlens array unit 111a. In the first microlens array unit 111a and the second microlens array unit 111b, the lens pitch of the microlens 111aa of the first microlens array unit 111a is larger than the lens pitch of the microlens 111ba of the second microlens array unit 111b. Is configured to be small (for example, “½” or less).

  In the screen 111 shown in FIG. 6, a plurality of microlenses 111aa and 111ba are formed on the surfaces facing the incident light side in the first microlens array unit 111a and the second microlens array unit 111b. In another example, a plurality of microlenses can be formed on the surfaces of the first and second microlens array portions facing the outgoing light side.

  FIG. 7 is a diagram illustrating a specific configuration of a screen 112 according to another example of the first modification. FIG. 7 shows a cross-sectional view of the first microlens array portion 112a and the second microlens array portion 112b of the screen 112 cut along a plane perpendicular to the light traveling direction. Specifically, a cross-sectional view showing a part of the first microlens array part 112a and the second microlens array part 112b in an enlarged manner is shown. It is assumed that light enters from the first microlens array portion 112a side.

  As shown in FIG. 7, the first microlens array portion 112a has a plurality of microlenses 112aa formed on the opposing surfaces of the first microlens array portion 112a and the second microlens array portion 112b. In the second microlens array portion 112b, a plurality of microlenses 112ba are formed on the surface opposite to the opposing surfaces of the first microlens array portion 112a and the second microlens array portion 112b. In other words, the first microlens array part 112a and the second microlens array part 112b include a surface of the first microlens array part 112a where the microlens 112aa is formed and a second microlens array where the microlens 112ba is not formed. It is arranged so as to face the surface of the portion 112b.

  Further, the first microlens array part 112a and the second microlens array part 112b are arranged at positions separated by a distance D2 that is at least longer than the focal length of the microlens 112aa of the first microlens array part 112a. In the first microlens array unit 112a and the second microlens array unit 112b, the lens pitch of the microlens 112aa of the first microlens array unit 112a is larger than the lens pitch of the microlens 112ba of the second microlens array unit 112b. Is configured to be small (for example, “½” or less).

  The screens 111 and 112 according to the first modification as described above also have the same operations and effects as the screen 11 according to the above-described embodiment.

(Modification 2)
The screen according to the modified example 2 is different from the above-described example and modified example 1 in that a plurality of microlenses are formed on the surfaces opposite to the opposed surfaces of the first and second microlens array portions. .

  FIG. 8 is a diagram illustrating a specific configuration of the screen 113 according to the second modification. FIG. 8 is a cross-sectional view in which the first microlens array portion 113a and the second microlens array portion 113b of the screen 113 are cut along a plane perpendicular to the light traveling direction. Specifically, a cross-sectional view in which a part of the first microlens array portion 113a and the second microlens array portion 113b is enlarged is shown. It is assumed that light enters from the first microlens array portion 113a side.

  As shown in FIG. 8, in the first microlens array portion 113a and the second microlens array portion 113b, a plurality of microlenses 113aa and 113ba are formed on the opposite surfaces of the opposing surfaces. That is, the first microlens array portion 113a and the second microlens array portion 113b are arranged to face each other so that the surfaces on which the plurality of microlenses 113aa and 113ba are formed face in opposite directions.

  In addition, the first microlens array unit 113a and the second microlens array unit 113b are arranged at positions separated by a distance D3 that is at least longer than the focal length of the microlens 113aa of the first microlens array unit 113a. In the first microlens array unit 113a and the second microlens array unit 113b, the lens pitch of the microlens 113aa of the first microlens array unit 113a is larger than the lens pitch of the microlens 113ba of the second microlens array unit 113b. Is configured to be small (for example, “½” or less).

  The screen 113 according to the second modified example has the same operation and effect as the screen 11 according to the above-described embodiment.

(Modification 3)
In Modification 3, the first and second microlens array portions are not configured separately as in the above-described embodiments and Modifications 1 and 2, and the first and second microlens array portions are configured integrally. A plurality of microlenses are formed on both sides of the screen.

  FIG. 9 is a diagram showing a specific configuration of the screen 114 according to the third modification. FIG. 9 shows a cross-sectional view of the screen 114 taken along a plane perpendicular to the light traveling direction. Specifically, a cross-sectional view showing a part of the screen 114b in an enlarged manner is shown. It is assumed that light enters from the first microlens array unit 114a side.

  As shown in FIG. 9, the screen 114 has a plurality of microlenses 114aa and 114ba formed on two opposing surfaces constituting the screen 114 (that is, on both surfaces). In other words, the screen 114 is integrally formed with a first microlens array part 114a in which a plurality of microlenses 114aa are formed and a second microlens array part 114b in which a plurality of microlenses 114ba are formed. That is, the screen 114 has a surface opposite to a surface on which the plurality of microlenses 114aa are formed in the first microlens array portion 114a and a surface on which the plurality of microlenses 114ba are formed in the second microlens array portion 114b. It is configured integrally by overlapping with the opposite surface.

  Further, the screen 114 is arranged such that the plurality of microlenses 114aa and the plurality of microlenses 114ba are separated by a distance D4 that is at least longer than the focal length of the microlens 114aa. That is, the screen 114 has a thickness corresponding to the distance D4 that is at least longer than the focal length of the microlens 114aa. In the first microlens array unit 114a and the second microlens array unit 114b, the lens pitch of the microlens 114aa of the first microlens array unit 114a is larger than the lens pitch of the microlens 114ba of the second microlens array unit 114b. Is configured to be small (for example, “½” or less).

  The screen 114 according to the third modified example has the same operation and effect as the screen 11 according to the above-described embodiment. Further, in the screen 114 according to the modified example 3, since the first microlens array unit 114a and the second microlens array unit 114b are integrally configured, only one component on which the microlens array is formed is created. Therefore, the cost required for the screen 114 can be further reduced as compared with the above-described embodiment and the first and second modifications.

(Modification 4)
The screen according to Modification 4 includes a vertex direction of a lens contour of a microlens arranged in one of the first and second microlens array units, and a microlens arranged in the other of the first and second microlens array units. This is different from the above-described embodiment and modifications 1 to 3 in that the angle with respect to the apex direction of the lens contour is shifted.

  FIG. 10 is a diagram illustrating a specific configuration of the screen 115 according to the fourth modification. FIG. 10A is an enlarged plan view showing a part of the first microlens array unit 115a and the second microlens array unit 115b of the screen 115, which is observed from the direction along the light traveling direction. ing. It is assumed that light enters from the first microlens array unit 115a side.

  FIG. 10B is a diagram defining the apex directions of regular hexagons that are the lens contours of the first microlens array unit 115a and the second microlens array unit 115b. The vertex direction is defined by the direction from the center point (center of gravity) of the regular hexagon as the lens contour toward each vertex of the regular hexagon. The left side of FIG. 10B shows the apex direction of the regular hexagon in the lens contour of the micro lens 115aa, and the right side of FIG. 10B shows the apex direction of the regular hexagon in the lens contour of the micro lens 115ba. Show. In the first microlens array unit 115a and the second microlens array unit 115b, the plurality of microlenses 115aa and 115ba are arranged in a lattice pattern, that is, the plurality of microlenses 115aa and 115ba are arranged in the same direction. Yes. Therefore, the vertex directions of the regular hexagonal shape are the same in the entire first microlens array portion 115a and the second microlens array portion 115b.

  As shown in FIGS. 10A and 10B, in the fourth modification, a regular hexagonal apex direction that is the lens contour of the microlens 115aa arranged in the first microlens array portion 115a, and the second The angle difference from the apex direction of the regular hexagon that is the lens contour of the micro lens 115ba arranged in the micro lens array unit 115b is configured to be 30 degrees. That is, the first microlens array unit 115a and the second microlens array unit 115b have a plurality of microlenses 115aa, so that the regular hexagonal shapes that are the lens contours of the microlenses 115aa and 115ba are rotated by 30 degrees. 115ba are arranged.

  As described above, the first microlens array unit 115a and the second microlens array unit 115b are configured so that the regular hexagonal shapes which are the lens contours of the microlenses 115aa and 115ba are rotated by 30 degrees with each other. Suppressing unnecessary interference between the regular hexagonal image formed by the first microlens array unit 115a on the incident surface of the microlens array unit 115b and the regular hexagonal shape that is the lens contour of the second microlens array unit 115b. it can. In other words, according to the fourth modification, the apex direction of the lens contour of the first microlens array unit 115a is shifted from the apex direction of the lens contour of the second microlens array unit 115b, and thus the second microlens array unit 115b. It is possible to blur the regular hexagonal image on the incident surface. Thereby, it is possible to appropriately suppress the influence due to the positional deviation between the first microlens array unit 115a and the second microlens array unit 115b.

  In addition, according to the fourth modification, the first microlens array unit 115a and the second microlens array are arranged by shifting the vertex directions of the lens contours in the first microlens array unit 115a and the second microlens array unit 115b. There is no need to exactly match the apex direction of the lens contour in the portion 115b, or to strictly configure the angle difference in the apex direction of the lens contour to a predetermined angle. According to Modification 4 as described above, the configuration of the comparative example (configuration described in Non-Patent Document 1) in which two microlens arrays are arranged so that the apex directions of the lens contours of the microlenses exactly coincide with each other. In comparison, the accuracy required for the arrangement of the lens contours in the apex direction in the first microlens array unit 115a and the second microlens array unit 115b can be reduced. From the above, according to the modified example 4, it is possible to create the screen 11 easily and at low cost as compared with the comparative example.

  Note that the unnecessary interference due to the regular hexagonal image as described above is that the angle difference in the apex direction of the regular hexagonal shape which is the lens contour of the first microlens array unit 115a and the second microlens array unit 115b is 30 degrees. Even without it, it is possible to suppress it. That is, in the above example, the angle difference in the apex direction of the regular hexagon that is the lens contour of the first microlens array unit 115a and the second microlens array unit 115b is shown as 30 degrees. The angle difference may not be 30 degrees, and the angle difference may be different from 30 degrees. This is because if the apex directions of the regular hexagons that are the lens contours of the first microlens array unit 115a and the second microlens array unit 115b are shifted to some extent (that is, if the apex directions of the regular hexagons do not match). This is because the regular hexagonal image on the incident surface can be blurred to some extent by the second microlens array unit 115b. However, according to experiments and the like, when the angle difference in the apex direction of the regular hexagon that is the lens contour is about 30 degrees or 90 degrees, the effect of suppressing unnecessary interference due to the regular hexagonal image is increased. I know that. Therefore, it is desirable that the angle difference in the apex direction of the regular hexagon that is the lens contour of the first microlens array unit 115a and the second microlens array unit 115b is set to about 30 degrees or about 90 degrees.

  As shown in FIG. 10A, the first microlens array unit 115a and the second microlens array unit 115b according to Modification 4 also have a lens pitch Pa1 in the microlens 115aa of the first microlens array unit 115a. The second microlens array unit 115b is configured to be smaller than the lens pitch Pb1 in the microlens 115ba of the second microlens array unit 115b (for example, “½” or less). Further, the first microlens array unit 115a and the second microlens array unit 115b are arranged to face each other at a position separated by at least a distance longer than the focal length of the microlens 115aa of the first microlens array unit 115a. Therefore, the screen 115 according to the modified example 4 has the same operation and effect as the screen 11 according to the above-described embodiment.

  Note that the first microlens array portion 115a and the second microlens array portion 115b according to the modification 4 are arranged in the arrangement relationship as shown in the above-described embodiment and the modifications 1 and 2 (FIGS. 3A and 6). , FIG. 7 or FIG. 8) is applied. Or as shown in the modification 3 (refer FIG. 9), the 1st micro lens array part 115a and the 2nd micro lens array part 115b are comprised integrally.

(Modification 5)
The screens according to the above-described embodiments and modification examples 1 to 4 are configured by first and second microlens array units having microlenses having a regular hexagonal shape in which the lens contour has the same length of all sides. It had been. On the other hand, the screen according to the modified example 5 has the first and second microlenses having a substantially regular hexagonal shape (that is, a hexagonal shape in which the lengths of all sides are not the same), and the lens contour is not a regular hexagonal shape. The second microlens array unit is configured.

  FIG. 11 is a diagram illustrating a specific configuration of the screen 116 according to the fifth modification. Specifically, FIG. 11 is an enlarged plan view showing a part of the first microlens array unit 116a and the second microlens array unit 116b included in the screen 116, as observed from the direction along the light traveling direction. Is shown. It is assumed that light is incident from the first microlens array unit 116a side.

  As shown in FIG. 11, each of the first microlens array unit 116a and the second microlens array unit 116b includes a plurality of microlenses 116aa and 116ba each having a hexagonal lens outline in a plan view. Yes. Specifically, the microlenses 116aa and 116ba are not regular hexagonal shapes (that is, the lengths of all the sides are not the same), but are configured by hexagonal lens contours having line-symmetric shapes.

  Further, in the first microlens array part 116a and the second microlens array part 116b, the lens pitch Pa2 in the microlens 116aa of the first microlens array part 116a is the lens pitch in the microlens 116ba of the second microlens array part 116b. It is configured to be smaller than Pb2 (for example, “½” or less). Further, the first microlens array unit 116a and the second microlens array unit 116b are disposed to face each other at a position separated by at least a distance longer than the focal length of the microlens 116aa of the first microlens array unit 116a. In this case, the first microlens array part 116a and the second microlens array part 116b are arranged as shown in the above-described embodiments and modifications 1 and 2 (FIG. 3A, FIG. 6, FIG. Any of (see FIG. 8) is applied. Or as shown in the modification 3 (refer FIG. 9), the 1st micro lens array part 116a and the 2nd micro lens array part 116b are comprised integrally.

  The screen 116 according to the modification 5 has the same operation and effect as the screen 11 according to the above-described embodiment.

  It should be noted that the configuration as shown in Modification 4 may be applied to the screen according to Modification 5. In other words, the first and second microlens array portions having the microlenses configured with the substantially regular hexagonal lens contour as shown in FIG. 11 are arranged in the lens contour of the microlens arranged in one microlens array portion. The angle between the apex direction and the apex direction of the lens contour of the microlens arranged in the other microlens array unit may be shifted.

  FIG. 12 is a diagram illustrating a specific configuration of a screen 117 according to another example of the fifth modification. Specifically, FIG. 12 is an enlarged plan view showing a part of the first microlens array unit 117a and the second microlens array unit 117b of the screen 117, which is observed from the direction along the light traveling direction. Is shown. It is assumed that light is incident from the first microlens array unit 117a side.

  As shown in FIG. 12, the hexagonal apex direction, which is the lens contour of the microlens 117aa arranged in the first microlens array portion 117a, and the lens contour of the microlens 117ba arranged in the second microlens array portion 117b. The angle difference from the vertex direction of the hexagonal shape is 90 degrees. That is, the first microlens array unit 117a and the second microlens array unit 117b have a plurality of microlenses 117aa and 117ba so that the hexagonal shapes that are the lens contours of the microlenses 117aa and 117ba are rotated by 90 degrees. It is arranged.

  The first microlens array unit 117a and the second microlens array unit 117b have a lens pitch Pa3 in the microlens 117aa of the first microlens array unit 117a and a lens pitch in the microlens 117ba of the second microlens array unit 117b. It is configured to be smaller than Pb3 (for example, “½” or less). Further, the first microlens array unit 117a and the second microlens array unit 117b are disposed to face each other at a position separated by at least a distance longer than the focal length of the microlens 117aa of the first microlens array unit 117a. In this case, the first microlens array unit 117a and the second microlens array unit 117b are arranged as shown in the above-described embodiment and modification examples 1 and 2 (FIG. 3A, FIG. 6, FIG. Any of (see FIG. 8) is applied. Or as shown in the modification 3 (refer FIG. 9), the 1st micro lens array part 117a and the 2nd micro lens array part 117b are comprised integrally.

  The screen 117 according to another example of Modification 5 has the same functions and effects as the screen 11 according to the above-described embodiment and the screen 115 according to Modification 4.

  The hexagonal shapes shown in FIGS. 11 and 12 are merely examples, and the present invention is not limited to configuring the lens contour of the microlens in such a hexagonal shape. Further, as shown in FIG. 12, the angle difference in the apex direction of the hexagonal shape that is the lens contour is not limited to 90 degrees.

(Modification 6)
The screens according to the above-described Examples and Modifications 1 to 5 are configured by the first and second microlens array units having microlenses whose lens contour is a hexagonal shape (regular hexagonal shape or substantially regular hexagonal shape). It was. On the other hand, the screen according to the modification 6 includes first and second microlens array units having microlenses whose lens contours are square.

  FIG. 13 is a diagram illustrating a specific configuration of the screen 118 according to the sixth modification. Specifically, FIG. 13 is an enlarged plan view showing a part of the first microlens array unit 118a and the second microlens array unit 118b of the screen 118, which is observed from the direction along the light traveling direction. Is shown. It is assumed that light is incident from the first microlens array unit 118a side.

  As shown in FIG. 13, each of the first microlens array unit 118a and the second microlens array unit 118b includes a plurality of microlenses 118aa and 118ba each having a square lens outline in a plan view. It is arranged. The first microlens array unit 118a and the second microlens array unit 118b have a lens pitch Pa4 in the microlens 118aa of the first microlens array unit 118a, and a lens pitch in the microlens 118ba of the second microlens array unit 118b. It is configured to be smaller than Pb4 (for example, “½” or less). Further, the first microlens array unit 118a and the second microlens array unit 118b are disposed to face each other at a position separated by at least a distance longer than the focal length of the microlens 118aa of the first microlens array unit 118a. In this case, the first microlens array unit 118a and the second microlens array unit 118b are arranged as shown in the above-described embodiments and the first and second modifications (FIGS. 3A, 6, 7, and 7). Any of (see FIG. 8) is applied. Or as shown in the modification 3 (refer FIG. 9), the 1st micro lens array part 118a and the 2nd micro lens array part 118b are comprised integrally.

  The screen 118 according to Modification 6 has the same operation and effect as the screen 11 according to the above-described embodiment.

  It should be noted that the configuration as shown in Modification 4 may be applied to the screen according to Modification 6. That is, the first and second microlens array portions having microlenses configured with square lens contours as shown in FIG. 13 are arranged at the apexes of the lens contours of the microlenses arranged in one microlens array portion. The angle between the direction and the apex direction of the lens contour of the microlens arranged in the other microlens array unit may be shifted.

  FIG. 14 is a diagram illustrating a specific configuration of a screen 119 according to another example of the sixth modification. Specifically, FIG. 14 is an enlarged plan view showing a part of the first microlens array unit 119a and the second microlens array unit 119b of the screen 119, which is observed from the direction along the light traveling direction. Is shown. It is assumed that light enters from the first microlens array portion 119a side.

  As shown in FIG. 14, the square apex direction which is the lens outline of the microlens 119aa arranged in the first microlens array part 119a and the lens outline of the microlens 119ba arranged in the second microlens array part 119b. The angle difference from the square apex direction is 45 degrees. That is, a plurality of microlenses 119aa and 119ba are provided in the first microlens array portion 119a and the second microlens array portion 119b so that the square shapes which are the lens contours of the microlenses 119aa and 119ba are rotated by 45 degrees. It is arranged.

  The first microlens array unit 119a and the second microlens array unit 119b have a lens pitch Pa5 in the microlens 119aa of the first microlens array unit 119a and a lens pitch in the microlens 119ba of the second microlens array unit 119b. It is configured to be smaller than Pb5 (for example, “½” or less). Further, the first microlens array unit 119a and the second microlens array unit 119b are disposed to face each other at a position separated by at least a distance longer than the focal length of the microlens 119aa of the first microlens array unit 119a. In this case, the first microlens array unit 119a and the second microlens array unit 119b are arranged as shown in the above-described embodiments and the first and second modifications (FIGS. 3A, 6, 7, and 7). Any of (see FIG. 8) is applied. Or as shown in the modification 3 (refer FIG. 9), the 1st micro lens array part 119a and the 2nd micro lens array part 119b are comprised integrally.

  The screen 119 according to another example of the modification 6 has the same operations and effects as the screen 11 according to the above-described embodiment and the screen 115 according to the modification 4.

(Modification 7)
Similar to the screen according to the modification 6, the screen according to the modification 7 includes first and second microlens array units having microlenses having a square lens outline. However, the screen according to the modified example 7 is different from the screen according to the modified example 6 in the arrangement of the microlenses having a square shape.

  FIG. 15 is a diagram illustrating a specific configuration of the screen 120 according to Modification 7. Specifically, FIG. 15 is an enlarged plan view showing a part of the first microlens array unit 120a and the second microlens array unit 120b of the screen 120, which is observed from the direction along the light traveling direction. Is shown. It is assumed that light is incident from the first microlens array unit 120a side.

  As shown in FIG. 15, each of the first microlens array unit 120a and the second microlens array unit 120b includes a plurality of microlenses 120aa and 120ba each having a square lens outline in plan view. Yes. Specifically, the first microlens array unit 120a and the second microlens array unit 120b are configured such that the microlenses 120aa and 120ba adjacent in the vertical direction are shifted by half the length of one side in the square shape. It is arranged.

  Further, in the first microlens array unit 120a and the second microlens array unit 120b, the lens pitch Pa6 in the microlens 120aa of the first microlens array unit 120a is the lens pitch in the microlens 120ba of the second microlens array unit 120b. It is configured to be smaller than Pb6 (for example, “½” or less). Furthermore, the first microlens array unit 120a and the second microlens array unit 120b are disposed to face each other at a position separated by at least a distance longer than the focal length of the microlens 120aa of the first microlens array unit 120a. In this case, the first microlens array unit 120a and the second microlens array unit 120b are arranged as shown in the above-described embodiments and the first and second modifications (FIGS. 3A, 6, 7, and 7). Any of (see FIG. 8) is applied. Or as shown in the modification 3 (refer FIG. 9), the 1st micro lens array part 120a and the 2nd micro lens array part 120b are comprised integrally.

  The screen 120 according to the modified example 7 has the same operation and effect as the screen 11 according to the above-described embodiment.

  Note that the configuration as shown in the above-described modification 4 may be applied to the screen according to the modification 7. That is, the first and second microlens array portions having the microlenses configured with the square lens contours as shown in FIG. 15 are arranged at the apexes of the lens contours of the microlenses arranged in one microlens array portion. The angle between the direction and the apex direction of the lens contour of the microlens arranged in the other microlens array unit may be shifted.

  FIG. 16 is a diagram illustrating a specific configuration of a screen 121 according to another example of the modification example 7. As illustrated in FIG. Specifically, FIG. 16 is an enlarged plan view showing a part of the first microlens array unit 121a and the second microlens array unit 121b included in the screen 121, as observed from the direction along the light traveling direction. Is shown. It is assumed that light enters from the first microlens array part 121a side.

  As shown in FIG. 16, a square apex direction which is a lens outline of the microlens 121aa arranged in the first microlens array part 121a and a lens outline of the microlens 121ba arranged in the second microlens array part 121b. The angle difference from the square apex direction is 45 degrees. That is, the first microlens array unit 121a and the second microlens array unit 121b have a plurality of microlenses 121aa and 121ba so that the square shapes of the lens contours of the microlenses 121aa and 121ba are rotated by 45 degrees. It is arranged.

  Further, in the first microlens array unit 121a and the second microlens array unit 121b, the lens pitch Pa7 in the microlens 121aa of the first microlens array unit 121a is the lens pitch in the microlens 121ba of the second microlens array unit 121b. It is configured to be smaller than Pb7 (for example, “½” or less). Furthermore, the first microlens array unit 121a and the second microlens array unit 121b are arranged to face each other at a position separated by at least a distance longer than the focal length of the microlens 121aa of the first microlens array unit 121a. In this case, the first microlens array part 121a and the second microlens array part 121b are arranged as shown in the above-described embodiments and modifications 1 and 2 (FIG. 3A, FIG. 6, FIG. Any of (see FIG. 8) is applied. Or as shown in the modification 3 (refer FIG. 9), the 1st micro lens array part 121a and the 2nd micro lens array part 121b are comprised integrally.

  The screen 121 according to another example of the modified example 7 has the same operations and effects as the screen 11 according to the above-described embodiment and the screen 115 according to the modified example 4.

  In the above-described modification examples 6 and 7, an example is shown in which the angular difference in the apex direction of the square shape that is the lens contour of the first and second microlens array portions is configured to be 45 degrees. The angle difference may not be 45 degrees, and the angle difference may be different from 45 degrees. The reason is as described in [Operation / Effect of Screen] in the above-described embodiment. However, according to experiments and the like, there is an effect of suppressing unnecessary interference due to the square-shaped image on the incident surface when the angle difference in the apex direction of the square shape that is the lens contour is around 45 degrees or around 135 degrees. I know it will grow. Therefore, it is desirable that the angle difference in the apex direction of the square shape, which is the lens contour of the first and second microlens array portions, be configured to be around 45 degrees or around 135 degrees.

  Moreover, although the modification 6 and 7 showed the example which comprises the lens outline of a micro lens in square shape, it is not limited to this, As described in the modification 5, the lens outline of a micro lens is substantially square shape. You may comprise (for example, rectangular shape).

(Modification 8)
The screens according to the above-described Examples and Modifications 1 to 7 have first and second microlenses having a lens contour having a regular hexagonal shape (including a substantially regular hexagonal shape) or a square shape (including a substantially square shape). It consisted of a microlens array part. On the other hand, the screen according to the modified example 8 includes first and second microlens array units having microlenses having a circular lens outline.

  FIG. 17 is a diagram illustrating a specific configuration of the screen 122 according to the seventh modification. Specifically, FIG. 17 is an enlarged plan view showing a part of the first microlens array unit 122a and the second microlens array unit 122b of the screen 122, which are observed from a direction along the light traveling direction. Is shown. It is assumed that light enters from the first microlens array portion 122a side.

  As shown in FIG. 17, each of the first microlens array unit 122a and the second microlens array unit 122b includes a plurality of microlenses 122aa and 122ba each having a circular lens outline in plan view. . Specifically, each of the micro lenses 122aa and 122ba has a plurality of micro lenses 122aa and 122ba arranged at equal intervals. The micro lenses 122aa and 122ba are arranged adjacent to each other at predetermined angles around one micro lens. FIG. 17 illustrates a case where the predetermined angle is 60 degrees.

  The first microlens array unit 122a and the second microlens array unit 122b have a lens pitch Pa8 in the microlens 122aa of the first microlens array unit 122a and a lens pitch in the microlens 122ba of the second microlens array unit 122b. It is configured to be smaller than Pb8 (for example, “½” or less). Further, the first microlens array part 122a and the second microlens array part 122b are arranged to face each other at a position separated by at least a distance longer than the focal length of the microlens 122aa of the first microlens array part 122a. In this case, the first microlens array part 122a and the second microlens array part 122b are arranged as shown in the above-described embodiments and modifications 1 and 2 (FIG. 3A, FIG. 6, FIG. Any of (see FIG. 8) is applied. Or as shown in the modification 3 (refer FIG. 9), the 1st micro lens array part 122a and the 2nd micro lens array part 122b are comprised integrally.

  The screen 122 according to the modified example 8 has the same operation and effect as the screen 11 according to the above-described embodiment.

  Note that the configuration shown in the above-described modification 4 may be applied to the screen according to modification 8. That is, the first and second microlens array units having microlenses configured with circular lens contours as shown in FIG. 17 may be configured to be in a relationship rotated by a predetermined angle.

  FIG. 18 is a diagram illustrating a specific configuration of a screen 123 according to another example of the modification example 8. As illustrated in FIG. Specifically, FIG. 18 is an enlarged plan view showing a part of the first microlens array portion 123a and the second microlens array portion 123b of the screen 123, which is observed from the direction along the light traveling direction. Is shown. It is assumed that light enters from the first microlens array portion 123a side.

  As shown in FIG. 18, the microlens 123aa arranged in the first microlens array unit 123a and the microlens 123ba arranged in the second microlens array unit 123b have a predetermined angle with respect to one microlens. It is shifted by 30 degrees corresponding to half. Further, in the first microlens array unit 123a and the second microlens array unit 123b, the lens pitch Pa9 in the microlens 123aa of the first microlens array unit 123a is the lens pitch in the microlens 123ba of the second microlens array unit 123b. It is configured to be smaller than Pb9 (for example, “½” or less). Furthermore, the first microlens array unit 123a and the second microlens array unit 123b are disposed to face each other at a position separated by at least a distance longer than the focal length of the microlens 123aa of the first microlens array unit 123a. In this case, the first microlens array part 123a and the second microlens array part 123b are arranged as shown in the above-described embodiments and modifications 1 and 2 (FIG. 3A, FIG. 6, FIG. Any of (see FIG. 8) is applied. Or as shown in the modification 3 (refer FIG. 9), the 1st micro lens array part 123a and the 2nd micro lens array part 123b are comprised integrally.

  The screen 123 according to another example of the modification 8 has the same operation and effect as the screen 11 according to the above-described embodiment and the screen 115 according to the modification 4.

  In Modification 8, it is preferable to mask between the microlenses constituting the first and second microlens array portions so as not to transmit light.

  Further, the lens contour of the microlens is not limited to a circular shape, and as described in the fifth modification, the lens contour of the microlens may be configured to have a substantially circular shape (for example, an oval shape). Furthermore, as shown in FIG. 18, the first and second microlens array units are not limited to be configured so as to have a relationship of being rotated by 30 degrees.

(Modification 9)
Although the example which applies this invention to a head up display was shown above, application of this invention is not limited to this. The present invention can be applied to a laser projector other than a head-up display. Since laser projectors usually suffer from speckle noise, it can be said that it is not desirable to use a screen for a liquid crystal projector. As described above, the screen according to the present invention can appropriately suppress spec noise and sufficiently secure a viewing angle, so that the screen according to the present invention can be suitably applied to a laser projector. it can.

  Further, the present invention can be applied to a head mounted display other than a head-up display and a laser projector.

  The present invention can be used for image display devices such as a head-up display, a head-mounted display, and a laser projector.

DESCRIPTION OF SYMBOLS 1 Image display apparatus 11 Screen 11a 1st micro lens array part 11b 2nd micro lens array part 11aa, 11ba Micro lens

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 a head-up display capable of appropriately suppressing excessive pixel bright spots in a configuration using a microlens array.

The invention according to claim 1 is a light source unit comprising a light source and an optical element having a first microlens array part and a second microlens array part in which a plurality of microlenses are arranged, The first microlens array unit and the second microlens array unit are arranged to face each other at positions separated from each other by a distance longer than a focal length of the microlens arranged in the first microlens array unit. An interval between the microlenses arranged in the microlens array unit is configured to be narrower than an interval between the microlenses arranged in the second microlens array unit, and the first microlens array unit includes the It is arranged on the incident side of light emitted from the light source with respect to the second micro-lens array section, the first micro Nzuarei portion and the second micro lens array section is formed integrally, the first micro lens array section is formed on one surface of the optical element, the second microlens array portion and the other of the optical element It is formed on the surface.

According to a fifth aspect of the present invention, a head-up display includes the light source unit according to any one of the first to fourth aspects, and an image formed by the light source unit is visually recognized as a virtual image from a position of a user's eyes. Let

The invention according to claim 1 is a light source unit comprising a light source and an optical element having a first microlens array part and a second microlens array part in which a plurality of microlenses are arranged, The first microlens array unit and the second microlens array unit are arranged to face each other at positions separated from each other by a distance longer than a focal length of the microlens arranged in the first microlens array unit. An interval between the microlenses arranged in the microlens array unit is configured to be narrower than an interval between the microlenses arranged in the second microlens array unit, and the first microlens array unit includes the It is arranged on the incident side of the light emitted from the light source with respect to the second microlens array unit, and the first microlens array unit The second microlens array part is integrally formed, the first microlens array part is formed on one surface of the optical element, and the second microlens array part is the other side of the optical element. So that the light collected by the two or more microlenses of the first microlens array part is collected by being incident on one microlens of the second microlens array part, An interval between the microlenses arranged in the first microlens array unit and the second microlens array unit is set, and the first microlens array unit includes one pixel corresponding to incident light, Two or more pixels are formed by distributing with the two or more microlenses, and the second microlens array unit includes the first microlens. The two or more adjacent pixels distributed by the array unit are aggregated by the one microlens to form one pixel, the microlens arranged in the first microlens array unit, and the first The microlens arranged in the 2 microlens array part has a similar shape .

Claims (6)

An optical element having a first microlens array section and a second microlens array section in which a plurality of microlenses are arranged,
The first microlens array part and the second microlens array part are:
A distance longer than the focal length of the microlens arranged in the first microlens array portion, and disposed opposite to each other,
An interval between the microlenses arranged in the first microlens array portion is configured to be narrower than an interval between the microlenses arranged in the second microlens array portion,
The first microlens array part is disposed on the light incident side with respect to the second microlens array part ,
An optical element having the first microlens array portion on one surface and the second microlens array portion on the other surface .   The interval between the microlenses arranged in the first microlens array unit is configured to be equal to or less than “½” of the interval between the microlenses arranged in the second microlens array unit. The optical element according to claim 1. The microlenses interval between the optical element according to claim 1 or 2, characterized in that the spacing of the center of gravity of adjacent microlenses. The first microlens array part and the second microlens array part are spaced apart by a distance not less than 1.5 times and not more than 3 times the focal length of the microlens arranged in the first microlens array part. the optical element according to any one of claims 1 to 3, characterized in that it is opposed to. Comprising an optical element according to any one of claims 1 to 4, head-up display, characterized in that to view the image formed by the optical element as a virtual image from the position of the user's eyes. A light source;
A first microlens array in which a plurality of microlenses are arranged at a predetermined interval;
A second microlens array in which a plurality of microlenses are arranged at intervals wider than the predetermined interval;
Have
The second microlens array is disposed at a position separated by a distance longer than the focal length of the macro lens disposed in the first microlens array,
The first microlens array is disposed on an incident side of light emitted from the light source with respect to the second microlens array ,
The light source unit, wherein the first microlens array is formed on one surface of the optical element, and the second microlens array is formed on the other surface of the optical element .