JP6534302B2 - Video display device - Google Patents

Description

  BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to an image display apparatus that displays an image on a lens portion of glasses.

  In recent years, information terminals may be developed for the purpose of being wearable (wearable to the body). For example, development of a glasses-type terminal capable of displaying an image is in progress. In such an eyeglass-type terminal, a holographic optical element (hereinafter also referred to as HOE) may be used to obtain a bright image. As an example of the spectacles type terminal using HOE, there exist an image display apparatus of patent document 1, and a head mounted display, for example. The image display apparatus and the head mount display of Patent Document 1 introduce image light from an image display element into an eyepiece optical system including an eyepiece prism, and guide light by totally reflecting the image light incident into the eyepiece prism. Lead to the HOE attached to the eyepiece prism. The image light reflected and refracted in the HOE is incident on the user's observation pupil (for example, see FIG. 12 of the same document).

Unexamined-Japanese-Patent No. 2012-13908

  In order to obtain a brighter and clearer image than in the past, it has been considered to use a reflective display element (reflective display) for the above-described image display apparatus and head mounted display. When an image is generated using a reflective display device (reflective display), a light source for illuminating the reflective display device is additionally required. Since the light source needs to illuminate the reflective display element at a predetermined angle, the light source can not be installed in a direction along the shape of, for example, a temple of the head mounted display, and a case etc. for housing the light source is bulky The whole device may be large. If the light source is installed in a direction along the shape of the head mount display, for example, a temple, it is necessary to provide an optical system for reflecting and refracting light from the light source, such as a prism. The same problem as described above may occur because the optical system can not be arranged in the direction along the shape of the head mounted display. Therefore, an object of the present invention is to provide a compact image display apparatus using a reflective display element.

  The image display apparatus according to the present invention includes a light source supported by glasses, a first holographic optical element that reflects light from the light source in a predetermined direction, and an image display surface of light reflected by the first holographic optical element. And a second holographic optical element that reflects light reflected from the reflective display element in a predetermined direction and causes the light to be incident on the pupil of a person wearing glasses.

  According to the present invention, a compact video display device using a reflective display element can be realized.

FIG. 2 is a plan view showing the configuration of an image display apparatus using a prism. FIG. 1 is a plan view showing the configuration of a video display apparatus according to a first embodiment. 6 is a flowchart showing an operation of a control unit of the video display device according to the first embodiment. FIG. 7 is a view exemplifying a case where light control is insufficient in the image display device of the first embodiment. FIG. 7 is a plan view showing the configuration of a video display apparatus according to a second embodiment. FIG. 13 is a plan view showing the configuration of a video display device of Example 3. FIG. 16 is a view for explaining a virtual image observed through the second holographic optical element of the image display device in the third embodiment. FIG. 18 is a view for explaining a virtual image observed through the second holographic optical element of the image display device of the third embodiment and is a view for explaining the case where the second holographic optical element is smaller than the example of FIG. 7; FIG. 13 is a plan view showing the configuration of a video display device according to a fourth embodiment.

  Hereinafter, with reference to FIG. 1, an example of an image display apparatus configured using a prism and its problems will be described. FIG. 1 is a plan view showing the configuration of an image display device 8 using a prism. The video display device 8 is supported and fixed to the glasses. Hereinafter, the name and number of each part of the glasses are referred to as modern 91, temple 92, rim 93, lens 94, nose pad 95, and bridge 96. The image display device 8 includes a light source 11, a prism 82 for reflecting light from the light source 11 in a predetermined direction, and a reflection type display element for receiving the light reflected by the prism 82 on its image display surface and reflecting it in the predetermined direction. 13, holographic optical element 14 for reflecting light reflected from reflective display element 13 in a predetermined direction and causing it to be incident on pupil center 71 of a person wearing glasses, and control for controlling light source 11 and reflective display element 13 Part 15 is included. The light source 11, the prism 82, the reflective display element 13, and the control unit 15 are all supported by the temple 92 of the glasses, and a jig used to support and fix these components on the temple 92 Illustration of is omitted. The holographic optical element 14 is attached to the lens 94 of the glasses.

  The reflective display element 13 may be called a reflective display. As the reflective display element 13 (reflective display 13), for example, a reflective liquid crystal, a DMD (Digital Micromirror Device), a MEMS (Micro Electro Mechanical Systems) mirror scan display, or the like can be used. The invention is not limited to this, and the reflective display element 13 may be any type as long as it generates an image using light from other light sources.

  The position of the prism 82 can not be freely changed because the prism 82 needs to make the light ray incident on the reflective display element 13 at a predetermined angle. The size of the prism 82 depends on the size of the reflective display element 13. Since the prism 82 has to guide light so as to illuminate the entire reflective display element 13, it is necessary to enlarge the prism as the reflective display element 13 becomes larger. As is apparent from FIG. 1, the prism 82 may interfere with the wearing of the glasses. If the light source 11, the prism 82, and the reflective display element 13 are moved in the outer direction of the glasses so as not to hinder the wearing of the glasses, the overall size including the glasses is increased.

  In the following embodiments, an image display apparatus is disclosed in which the above-described problems are overcome and the miniaturization of the apparatus is realized. Note that components having the same function will be assigned the same reference numerals and redundant description will be omitted.

  The configuration of the video display apparatus according to the first embodiment will be described below with reference to FIG. FIG. 2 is a plan view showing the configuration of the video display device 1 of the present embodiment. As shown in FIG. 2, the image display apparatus 1 of the present embodiment includes a light source 11, a first holographic optical element (HOE) 12 that reflects light from the light source 11 in a predetermined direction, and a first holographic optical element 12. The light reflected by the light is received by the image display surface, and the reflection type display element 13 which reflects in a predetermined direction, and the reflection light from the reflection type display element 13 is reflected in a predetermined direction, and the pupil center of the person wearing the glasses And a control unit 15 for controlling the light source 11 and the reflective display device 13. The light source 11, the reflective display element 13, the second holographic optical element 14, and the control unit 15 have the same functions as the constituent elements of the image display apparatus 8 of FIG. In the present embodiment, the first holographic optical element 12 is added instead of the prism 82, so that the holographic optical element 14 in FIG. 1 is changed to the second holographic optical element 14 and its name is changed for convenience. But their role, nature and function are the same.

  The light source 11, the first holographic optical element 12, the reflective display element 13, and the control unit 15 are all supported by the temple 92 of the glasses, and these parts are used to support and fix the part to the temple 92. Illustration of jigs (fittings) is omitted. The light source 11, the first holographic optical element 12, the reflective display element 13, and the control unit 15 may be supported by any part of the glasses other than the temple 92. The second holographic optical element 14 is attached to the lens 94 of the glasses as described above.

  The operation of the control unit 15 will be described with reference to FIG. FIG. 3 is a flowchart showing the operation of the control unit 15 of the video display device 1 of the present embodiment. As shown in FIG. 3, the control unit 15 controls the light source 11 (S15-1), and controls the reflective display element 13 (S15-2).

  For example, when the reflective display element 13 is a DMD (MEMS mirror array display), the control unit 15 controls the light source 11 to switch RGB (red / green / blue) light in order at a high speed while switching (S15-1). The control unit 15 controls the tilt of the microminiature mirror included in the reflective display element 13 to reflect the light of each color output from the light source 11 at a predetermined angle (S15-2). For the light source 11, for example, an LED may be used. The light source 11 may be a combination of a white LED and an RGB color wheel rotating at high speed. In this case, the control unit 15 controls the RGB color wheel in step S15-1. In addition, the light source 11 includes a lens or the like that collimates light incident on the first holographic optical element 12.

  In addition, although the video display apparatus 1 of FIG. 2 is comprised so that an image | video may be displayed only to a right eye, not only this but the video display apparatus 1 may be comprised so that an image may be displayed only to a left eye. Alternatively, the light source 11, the first holographic optical element 12, the reflective display element 13, the second holographic optical element 14, and the control unit 15 may be provided one by one on the left and right so that an image can be displayed to both eyes. Even one control unit 15 can be realized).

  The lens 94 may be provided with a liquid crystal shutter. By performing control to close the liquid crystal shutter when displaying an image, the image can be made brighter by the contrast effect, and the visibility of the image can be improved. In addition, a remote control for operating an object or the like displayed in the video may be connected to the video display device 1. By connecting a remote control to the video display device 1, an object displayed in the video can be operated, and the video display device 1 can be used as an information terminal.

  Holographic optical elements by their nature allow the angle of incidence and the angle of reflection of light rays to be different. This property is a property not found in other optical systems such as a prism. Using this property, the first holographic optical element 12 can reflect a light beam in a direction independent of the incident angle of the light beam from the light source 11 and can guide the light to the reflective display device 13. As a result, both the surfaces of the light source 11 and the first holographic optical element 12 can be disposed in the direction along the shape of the glasses, which contributes to the downsizing of the device. In addition, the holographic optical element has a property of reflecting light rays of a predetermined incident angle while transmitting light rays incident at other angles. For this reason, the light reflected from the reflective display element 13 is once again the first holographic optical element because the first holographic optical element 12 and the reflective display element 13 have to be arranged in a narrow area, etc. Even when the light beam 12 is incident on this, it can be transmitted through and well guided to the second holographic optical element 14. The property of selectively reflecting / transmitting a light beam depending on the incident angle is also recognized in a prism, but when using a prism, it becomes a problem that the size becomes too large as in the example of the prism 82 of FIG. Since the holographic optical element has a thin shape and the same function as a prism, it contributes to the miniaturization of the device.

  As described above, according to the image display apparatus 1 of the present embodiment, since the light from the light source 11 is guided to the reflective display element 13 using the first holographic optical element 12, parts necessary for image generation can be obtained. The arrangement can be made along the shape of the glasses, so that the device can be miniaturized.

  FIG. 4 is a diagram illustrating a case where light control is insufficient in the image display apparatus 1 of the first embodiment. In the example of FIG. 4, the light reflected by the reflective display element 13 is diffused to the nose pad 95 and can not be well led onto the second holographic optical element 14. The image display apparatus according to the second embodiment aims to improve the light guiding control to the second holographic optical element 14 as shown in FIG. 4 when the light guiding control is insufficient.

  Hereinafter, the video display apparatus according to the second embodiment will be described with reference to FIG. FIG. 5 is a plan view showing the configuration of the video display apparatus 2 of the present embodiment. As shown in FIG. 5, in addition to the configuration of the image display device 1 of the first embodiment, the image display device 2 of the present embodiment includes a third holographic optical element 21. The third holographic optical element 21 is located between the reflective display element 13 and the second holographic optical element 14, and transmits and refracts the reflected light from the reflective display element 13, thereby the second holographic optical element 14. Guide to

  The third holographic optical element 21 is added for the purpose of correcting the direction of the light beam, for example, when the design conditions are severe and the reflected light from the reflective display element 13 can not be effectively guided to the second holographic optical element 14. Ru.

  According to the image display device 2 of the present embodiment, in addition to the same effect as that of the first embodiment, by adding the third holographic optical element 21, the reflected light from the reflective display element 13 can be effectively transmitted to the second holographic optical element. It can be guided to the graphic optics 14.

  Hereinafter, the video display apparatus according to the third embodiment will be described with reference to FIG. FIG. 6 is a plan view showing the configuration of the video display apparatus 3 of the present embodiment. As shown in FIG. 6, in the configuration of the image display apparatus 1 according to the first embodiment, the image display apparatus 3 according to the present embodiment has a configuration in which the first holographic optical element 12 is replaced with the first holographic optical element 32. It is.

  The first holographic optical element 32 has a function of reflecting the light from the light source 11 in a predetermined direction and guiding the light to the reflective display element 13 as in the first embodiment. It also has a function of transmitting and refracting light reflected from the display element 13 and incident again and guiding the light to the second holographic optical element 14. That is, the first holographic optical element 32 of the present embodiment has both the function of the first holographic optical element 12 of the first embodiment and the function of the third holographic optical element 21 of the second embodiment.

  The image display apparatus 3 of this embodiment includes the first holographic optical element 32 having the light guiding function to the reflective display element 13 and the light guiding function to the second holographic optical element 14. The same effect as that of Example 1 can be obtained.

  Hereinafter, a virtual image observed through the first holographic optical element 32 will be described with reference to FIGS. 7 and 8. In the image display device 3 of the present embodiment, the second holographic optical element 14 is designed so as to reproduce light diffused (diffused) from each pixel of the reflective display element 13. The light from the first holographic optical element 32 diffused with a certain width is irradiated to the second holographic optical element 14 and reflected thereby to form a virtual image 60 (virtual pixel 61) of a predetermined solid angle at the position shown in FIG. , 62, 63) can be generated. From the user's point of view, since the second holographic optical element 14 is, so to speak, the same as a peep hole for observing the virtual image 60, if the second holographic optical element 14 becomes small in size, it is observed as the virtual image 60. The range also becomes smaller.

  For example, when the second holographic optical element 14 is smaller than the case illustrated in FIG. 7 as illustrated in FIG. 8, the solid angle of the virtual image 60 is necessarily smaller. This can be expressed as the light from the virtual pixel 61 'located at the end of the virtual image does not enter the eyeball if the virtual image 60 is made to have the same size as in the case of FIG. See the thin arrows in).

  In order to realize a large screen image, it is necessary to increase the illumination area to the second holographic optical element 14. Therefore, the first holographic optical element 32 is provided with a lens function (function to expand and transmit the light from the reflective display element 13), and the transmission and refraction angle is adjusted in the first holographic optical element 32. 2) The holographic optical element 14 is illuminated at a shallow angle to expand the horizontal direction (horizontal direction) of the image. Furthermore, by the lens function of the first holographic optical element 32, the irradiation area to the second holographic optical element 14 can be enlarged by mainly enlarging the longitudinal direction (vertical direction) of the image. The enlargement of the image in the lateral direction (horizontal direction) may not depend on the adjustment of the angle, but may depend on the lens function of the first holographic optical element 32. This point will be described in detail in the fourth embodiment.

  Hereinafter, the video display apparatus according to the fourth embodiment will be described with reference to FIG. FIG. 9 is a plan view showing the configuration of the video display device 4 of the present embodiment. As shown in FIG. 9, the video display apparatus 4 of the present embodiment has the first holographic optical element 32 as the first holographic optical element 42 in the configuration of the video display apparatus 3 of the third embodiment. The graphic optical element 14 is replaced with a second holographic optical element 44.

  As shown in the above-mentioned embodiment (FIG. 2, the arrangement example of FIG. 4 to FIG. 6), the reflective display element 13 is supported and fixed to the temple 92 of the glasses, and the second holo attached to the lens 94 from this position. In order to illuminate the graphic optical element 14, light from the reflective display element 13 is incident on the second holographic optical element 14 from an oblique direction. As a result, the image generated by the reflective display element 13 is an image stretched in the horizontal direction on the second holographic optical element 14. In the first to third embodiments, the deformation of the image due to the optical factor can be resolved by adjusting on the software side. For example, the vertical direction of the image generated by the reflective display element 13 may be stretched to a predetermined ratio, or the horizontal direction of the image may be reduced to a predetermined ratio. However, when the image is deformed by software, there is a problem that the resolution is degraded in the stretched direction.

  Therefore, in the present embodiment, this problem is solved by providing the first holographic optical element 42 with a condensing or diffusing function. The first holographic optical element 42 has a function of reflecting light from the light source 11 in a predetermined direction and guiding the light to the reflective display element 13 as in the first embodiment and the third embodiment. Similarly, it has a function of transmitting and refracting light reflected from the reflective display element 13 and incident again, and guiding the light to the second holographic optical element 44. At this time, the first holographic optical element 42 sets the light reflected from the reflective display element 13 and re-entered into a light receiving area of the second holographic optical element 44 with a predetermined horizontal width or vertical width. Control the reflected light to be stretched or compressed. For example, the first holographic optical element 42 refracts and transmits the reflected light so that the horizontal width of the light receiving area of the second holographic optical element 44 is equal to the horizontal width of the reflective display element 13. Light control.

  The second holographic optical element 44 may be the same as the second holographic optical element 14 in the first to third embodiments, but may be changed in size in accordance with the control of the first holographic optical element 42. For example, when the first holographic optical element 42 performs horizontal focusing control, the horizontal width may be reduced accordingly. When the first holographic optical element 42 performs diffusion control in the vertical direction, the width in the vertical direction may be expanded accordingly.

  In this embodiment, the first holographic optical element 42 has a condensing or diffusing function, and the horizontal width or the vertical width of the light receiving area (image light projection area) of the second holographic optical element 44 is predetermined. The reflected light is controlled so as to be expanded or compressed to a width of, but a similar modification may be performed on, for example, the third holographic optical element 21 of the second embodiment. By providing the third holographic optical element 21 with a condensing or diffusing function, the third holographic optical element 21 not only performs the light guiding function to the second holographic optical element 14, but also the second holographic optical element 21. The reflected light is controlled so that the horizontal width or the vertical width of the light receiving area (image light projection area) of the optical element 14 is expanded or compressed to a predetermined width.

  According to the video display device 4 of the present embodiment, in addition to the effects of the third embodiment, the aspect ratio of video can be adjusted without degrading the resolution.

<Supplementary Note>
The apparatus according to the present invention is, for example, an input unit to which a keyboard or the like can be connected, an output unit to which a liquid crystal display or the like can be connected as a single hardware entity, or a communication apparatus (eg, communication cable) capable of communicating outside the hardware entity Communication unit that can be connected, CPU (central processing unit, cache memory, registers, etc. may be provided), RAM or ROM that is memory, external storage device that is hard disk, input unit for these, output unit, communication unit , A CPU, a RAM, a ROM, and a bus connected so as to enable exchange of data between external storage devices. If necessary, the hardware entity may be provided with a device (drive) capable of reading and writing a recording medium such as a CD-ROM. Examples of physical entities provided with such hardware resources include general purpose computers, microcomputers, and microcontrollers.

  The external storage device of the hardware entity stores a program necessary for realizing the above-mentioned function, data required for processing the program, and the like (not limited to the external storage device, for example, the program is read) It may be stored in the ROM which is a dedicated storage device). In addition, data and the like obtained by the processing of these programs are appropriately stored in a RAM, an external storage device, and the like.

  In the hardware entity, each program stored in the external storage device (or ROM etc.) and data necessary for processing of each program are read into the memory as necessary, and interpreted and processed appropriately by the CPU . As a result, the CPU realizes predetermined functions (each component requirement expressed as the above-mentioned,...

  The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention. Further, the processing described in the above embodiment may be performed not only in chronological order according to the order of description but also may be performed in parallel or individually depending on the processing capability of the device that executes the processing or the necessity. .

  As described above, when the processing function in the hardware entity (the apparatus of the present invention) described in the above embodiment is implemented by a computer, the processing content of the function that the hardware entity should have is described by a program. Then, by executing this program on a computer, the processing function of the hardware entity is realized on the computer.

  The program describing the processing content can be recorded in a computer readable recording medium. As the computer readable recording medium, any medium such as a magnetic recording device, an optical disc, a magneto-optical recording medium, a semiconductor memory, etc. may be used. Specifically, for example, as a magnetic recording device, a hard disk device, a flexible disk, a magnetic tape or the like as an optical disk, a DVD (Digital Versatile Disc), a DVD-RAM (Random Access Memory), a CD-ROM (Compact Disc Read Only) Memory), CD-R (Recordable) / RW (Rewritable), etc. as magneto-optical recording medium, MO (Magneto-Optical disc) etc., as semiconductor memory EEP-ROM (Electronically Erasable and Programmable Only Read Memory) etc. Can be used.

  Further, this program is distributed, for example, by selling, transferring, lending, etc. a portable recording medium such as a DVD, a CD-ROM or the like in which the program is recorded. Furthermore, this program may be stored in a storage device of a server computer, and the program may be distributed by transferring the program from the server computer to another computer via a network.

  For example, a computer that executes such a program first temporarily stores a program recorded on a portable recording medium or a program transferred from a server computer in its own storage device. Then, at the time of execution of the process, the computer reads the program stored in its own recording medium and executes the process according to the read program. Further, as another execution form of this program, the computer may read the program directly from the portable recording medium and execute processing according to the program, and further, the program is transferred from the server computer to this computer Each time, processing according to the received program may be executed sequentially. In addition, a configuration in which the above-described processing is executed by a so-called ASP (Application Service Provider) type service that realizes processing functions only by executing instructions and acquiring results from the server computer without transferring the program to the computer It may be Note that the program in the present embodiment includes information provided for processing by a computer that conforms to the program (such as data that is not a direct command to the computer but has a property that defines the processing of the computer).

  Further, in this embodiment, the hardware entity is configured by executing a predetermined program on a computer, but at least a part of the processing content may be realized as hardware.

8 image display apparatus 91 modern 92 temple 93 rim 94 lens 95 nose pad 96 bridge 11 light source 82 prism 13 reflection type display element 14 (second) holographic optical element 15 control unit 71 pupil center 1 image display apparatus 12 first holographic Optical element 2 Image display device 21 Third holographic optical element 3 Image display device 32 First holographic optical element 4 Image display device 42 First holographic optical element 44 Second holographic optical element 60 Virtual image 61 Virtual pixel 61 'Virtual Pixel 62 virtual pixel 63 virtual pixel

Claims (1)

A light source supported by the glasses,
A first holographic optical element that reflects light from the light source in a predetermined direction;
A reflective display element which receives the light reflected by the first holographic optical element on its image display surface and reflects it in a predetermined direction;
The second holographic optical element includes a second holographic optical element that reflects light reflected from the reflective display element in a predetermined direction and causes the light to be incident on a pupil of a person wearing the glasses.
The first holographic optical element is
The light reflected from the reflective display element is transmitted and refracted, and is guided to the second holographic optical element,
The image display apparatus which controls the said reflected light so that the width | variety of the light reception area | region of a said 2nd holographic optical element may be expand | extended or compressed to predetermined | prescribed width | variety.

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