JP7142164B2 - Glasses-type image display device - Google Patents

Description

The present invention relates to a spectacles-type image display device. It should be noted that the “image” includes still images and moving images.

2. Description of the Related Art Conventionally, there is known a spectacles-type image display device that displays an image on lens surfaces of spectacles (see Patent Document 1, for example). In the spectacles-type image display device described in Patent Document 1, an image is projected from a direction perpendicular to the lens surface of the spectacles. Further, in recent years, in order to downsize the spectacles-type image display device and make it easier to handle, a technique is known in which an image is obliquely projected onto the lens surface of the spectacles from the temple side of the spectacles.

JP 2016-131270 A

In the technical field related to the spectacles-type image display device as described above, the range in which an image can be seen even if the user wears the spectacles-type image display device and moves his/her eyes is called "Eyebox". Enlarging the Eyebox is essential for stable image viewing.

As a technology related to the conventional spectacles-type image display device, for example, there is a retinal projection method in which image light is projected toward the user's eyes. , is in a state of being nearly parallel, and is known as a method that has no or very little influence of light refraction in the human lens. This retinal projection method has been known as a method with a narrow eyebox, but a method of widening the eyebox is also being studied. However, in that case, it has been pointed out that there is a limit to the viewing angle. As described above, in the technology related to the conventional spectacles-type image display device, it has been a problem to expand the eyebox while maintaining a wide viewing angle.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a spectacles-type image display device capable of enlarging an eyebox while maintaining a wide viewing angle.

A spectacles-type image display device according to one aspect of the present invention is a spectacles-type image display device including an image output unit that emits image light, which is light containing image information, toward lens surfaces of spectacles, wherein the image a diffractive optical system element that replicates image light emitted from an output unit; and a diffractive optical system element that reacts independently to each light replicated by the diffractive optical system element. and a direction adjustment optical system element for adjusting the direction so that the image display devices are directed to the eyes of a user wearing the image display device and advance in directions parallel to each other.

In such a spectacles-type image display device, image light, which is light containing image information, is emitted from the image output unit toward the lens surface of the spectacles, and the emitted image light is duplicated by the diffractive optical system element. Then, the direction-adjusting optical system element reacts independently to each of the duplicated lights, and each light after the reaction during the reaction is directed to the eyes of the user wearing the spectacles-type image display device, Orient them so that they are parallel to each other. After the above reactions, the lights travel in parallel directions toward the user's eye, and are perceived by the user as coming from the same direction. Therefore, it is possible to enlarge the Eyebox, which is the range in which the image can be seen even if the user moves his or her eyes. On the other hand, details will be described later with reference to FIG. Since the viewing angle is the viewing angle during playback, it is possible to widen the viewing angle during playback by adjusting the angle of the object light at the time of creation (exposure). In this way, the eyebox can be enlarged while maintaining a wide viewing angle.

According to the present invention, it is possible to provide a spectacles-type image display device capable of enlarging the eyebox while maintaining a wide viewing angle.

It is a figure which shows the spectacles type image display apparatus typically. Fig. 2 shows a first aspect of light replication and reflection; FIG. 10 is a diagram for explaining intervals between duplicated lights; (a) is a diagram for explaining the creation of a hologram, and (b) is a diagram for explaining the reproduction of the hologram. (a) is a diagram for explaining reproduced light when a scan display is used, and (b) is a diagram for explaining reproduced light when a flat display is used. FIG. 4 is a diagram for explaining a configuration for shaping reproduced light to be thinner; FIG. 4 is a diagram for explaining multiple recording of holograms; FIG. 10 illustrates a second aspect of light replication and reflection; It is a figure for demonstrating the 3rd aspect using a waveguide. FIG. 2 is a diagram for explaining an outline of a waveguide; FIG. (a) is a diagram for explaining the overall image of reproduced light, and (b) is a diagram showing one unit forming (a). It is a figure which shows the hardware structural example of a control part.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the accompanying drawings. In the description of the drawings, the same elements are denoted by the same reference numerals, and overlapping descriptions are omitted.

FIG. 1 is a diagram schematically showing a spectacles-type image display device 1 according to an embodiment of the invention. The spectacles-type image display device 1 is a display device that allows a user wearing spectacles (hereinafter simply referred to as "user") to visually recognize an image (still image and moving image) on the lens surface of the spectacles. be. The spectacles-type image display device 1 allows the user to visually recognize an image by causing the image light emitted from the image display unit 10 attached to the temple 52 of the spectacles to enter the user's pupils. As illumination light used for display display in the image display unit 10, LED (Light Emitting Diode) light may be used, or laser light may be used.

The spectacles-type image display device 1 has the basic configuration of spectacles, and as shown in FIG. , and a pair of temples 52 that are continuous with a frame that holds lenses 50 for both eyes and that are fixed to the temporal region of the user. Lens 50 reflects at least a portion of the incident (projected) image light toward the user's pupil. The image light reflected by the incident surface of the lens 50 forms a virtual image when viewed from the pupil. This allows the user to visually recognize the image. The spectacles-type image display device 1 may have a speaker (not shown) that outputs sound corresponding to an image at a position corresponding to the user's ear on the temple 52 .

The glasses-type image display device 1 includes an image display unit 10 . The image display unit 10 includes a content storage section 11 , an image output section 12 and a control section 13 . Among them, the image output unit 12 is arranged on the temple 52, for example. The spectacles-type image display apparatus 1 has each configuration of the image display unit 10 described above corresponding to each eye, but the functions of the configurations corresponding to each of the eyes are the same. , only the configuration corresponding to one eye will be described in the following description.

The content storage unit 11 is configured to store content to be viewed by the user, and the content to be viewed by the user is an image projected onto the lens 50 in this embodiment. The content storage unit 11 may be arranged on the temple 52 or may be arranged at a position away from the temple 52 .

The image output unit 12 is configured to output image light, which is light containing image information, acquires image information from the content storage unit 11 through a wired or wireless connection, and emits image light related to the acquired image information. The image output unit 12 includes a light source and a display, reflects the irradiation light emitted from the light source on the display, and outputs it as image light including image information.

The control unit 13 is a circuit that performs various controls. A hardware configuration of the control unit 13 will be described later. For example, the control unit 13 outputs a predetermined control signal to the image output unit 12 so that the image output unit 12 acquires an image from the content storage unit 11 and emits image light.

[Features of the spectacles-type image display device 1]
Viewed from a functional aspect, the spectacles-type image display device 1 has a "diffractive optical system element" that duplicates the image light emitted from the image output unit 12, reacts independently to each of the duplicated lights, Equipped with a "direction adjustment optical system element" that adjusts the direction so that each light after the reaction is directed to the user's eye and travels in parallel directions, and adopts the following various modes. can be done.

(First aspect)
A first aspect of the above diffractive optical system element and direction adjusting optical system element will be described below. As shown in FIG. 2, in the first aspect, the diffractive optical system element is composed of a transmission hologram 20A that replicates the image light emitted from the image output unit 12 into a plurality of lights and transmits them. The system element independently reflects a plurality of lights transmitted by the transmission hologram 20A, and each light reflected at the time of the reflection is directed to the eyes of the user wearing the spectacles-type image display device 1 and is parallel to each other. , a reflection hologram 30A that is oriented so that it travels in the direction of Here, "going in parallel directions" means that image light from pixels at the same location in the same image, after being replicated and reflected, travels in parallel directions toward the user's eye. . The transmission hologram 20A is formed on the surface of the spectacle lens surface 50A closer to the user's eyes (the lower surface in FIG. 2), and the reflection hologram 30A is formed on the surface of the spectacle lens surface 50A farther from the user's eyes (the lower surface in FIG. 2). upper surface). Here, an example in which both the diffractive optical system element and the direction adjusting optical system element are composed of holograms is shown, but they may be composed of laminated diffraction gratings or the like other than holograms.

For the sake of explanation, FIG. 2 shows the paths of the light A and B at the ends of the image light, and their transmitted light and reflected light. The transmission hologram 20A duplicates and transmits the incident image light A into a plurality of lights A1, A2, and A3, and the reflection hologram 30A independently reflects the plurality of lights A1, A2, and A3. The reflected lights AR1, AR2, AR3 are directed to the user's eye and travel in directions parallel to each other. Similarly, the transmission hologram 20A duplicates and transmits the incident image light B into a plurality of lights B1, B2, and B3, and the reflection hologram 30A independently reflects the plurality of lights B1, B2, and B3 to are directed so that the light BR1, BR2, BR3 reflected during .DELTA. When the image light is duplicated by the transmission hologram 20A as described above, it is desirable to adjust the degree of aberration of each light after duplication to be the same. Specifically, in FIG. 2, the duplicated lights A1 and B1 are adjusted to be parallel. Similarly, the duplicated lights A2 and B2 are adjusted to be parallel, and the duplicated lights A3 and B3 are adjusted to be parallel. By adjusting so that the light rays after replication travel in parallel as described above, it is possible to adjust so that the degree of aberration of each light A1, A2, and A3 replicated from the image light A is the same. The degree of aberration of each light B1, B2, B3 replicated from light B can also be adjusted to be the same. The direction adjustment function described above is realized by utilizing multiple recording of holograms, which will be described later.

As shown in FIG. 3, the reflected lights AR1 and BR1 converge, for example, on the user's pupil, similarly the reflected lights AR2 and BR2 converge on the pupil, and the reflected lights AR3 and BR3 also converge on the pupil. A plurality of light beams duplicated as described above enter the user's pupil, and the Eyebox has a range W2 corresponding to the number of light beams arranged in parallel. Although FIG. 3 is an example, the interval W1 for arranging a plurality of lights is desirably around 2 mm in a bright environment and around 5 mm in a dark environment, and is designed so that two or more rays enter the pupil.

Here, the creation (exposure) and reproduction of a hologram will be briefly described. As shown in FIG. 4A, a hologram is created (exposed) using a wavefront (object light) indicated by broken lines and a wavefront (reference light) indicated by solid lines. As for the reproduction, the non-diffused image light indicated by the solid line in FIG. 4B is used as the reproduction light. At this time, the principal ray of the image light is adjusted to match the reference light (the solid line in FIG. 4A) during exposure. As a result, the dotted line light with a wide viewing angle is reproduced in FIG. 4(b). Here, the angle of the object light at the time of hologram creation (exposure) is the viewing angle at the time of reproduction, so by adjusting the angle of the object light at the time of hologram creation (exposure), we aim to widen the viewing angle at the time of reconstruction. be able to.

Next, the reproducing optical system will be outlined with reference to FIGS. 5(a) and 5(b). As shown in FIG. 5A, when the light source of the reproduction light is a scan display, the direction of the light beam of the scan display is set so as to match the direction of the reference light beam during hologram exposure. Further, as shown in FIG. 5B, when the light source of the reproduction light is a flat display (for example, Liquid crystal on silicon (Lcos) (registered trademark)), the adjustment lens 60 is used to adjust the reproduction light. The direction of the principal ray is set so as to match the direction of the reference ray during hologram exposure. In the above configuration, even if the angle X in FIG. 5A and the angle Y in FIG. There is an advantage that a wide viewing angle can be achieved during reproduction by adjusting the angle of the object light.

In displays such as Lcos (registered trademark) and DMD (Digital Micromirror Device), which are widely used in general, the pixel size is small, so the pixels act like diffraction gratings (slits) and the display light (reproduced light) is diffused. It is known. Therefore, as shown in FIG. 6, a molding lens 61 (molding optical system element) may be further provided for molding the diffused reproduction light to be thinner. In this case, blurring of the image can be prevented, and high resolution can be achieved.

As described above, the reflection hologram 30A of FIG. 2 independently reflects a plurality of lights A1, A2, and A3, and the lights AR1, AR2, and AR3 reflected during the reflection are directed toward the user's eyes, Orient it so that it goes in a parallel direction. Such a direction adjustment function is realized by using multiple recording of holograms. Multiplex recording of holograms is a recording method for creating a plurality of interference fringes in one hologram, and is actually realized in a thick volume hologram. As shown in FIG. 7, if multiplex recording of holograms is performed, even if a plurality of light beams are incident on the spectacle lens surface at once, the holograms provided on the spectacle lens surface (holograms subjected to multiplex recording) are It can be configured to independently reflect light rays in any direction. For example, in FIG. 7, even if the light beams X1 and Y1 are incident on the spectacle lens surface at once, the hologram X formed on the spectacle lens surface reflects the light beam X1 in the direction of the arrow X2, and the light beam X1 is similarly formed on the spectacle lens surface. Hologram Y can be configured to independently reflect ray Y1 in the direction of arrow Y2. Here, the hologram X and the hologram Y can be formed in the form of a single film as a volume hologram. In this case, due to the angular dependence of the hologram, the hologram X reacts to the ray X1 but not to the ray Y1 incident at a different angle than the ray X1. Also, the hologram Y reacts to the ray Y1, but does not react to the ray X1 incident at a different angle than the ray Y1. Thereby, it is possible to realize a configuration in which a plurality of lights incident at different angles are independently reflected.

(Second aspect)
Next, a second aspect of the diffractive optical system element and the direction adjusting optical system element will be described. As shown in FIG. 8, in the second embodiment, the diffractive optical system element is composed of a reflection hologram 30B that replicates the image light emitted from the image output unit 12 into a plurality of lights and reflects them. Optical elements independently transmit the plurality of lights reflected by the reflection hologram 30B and direct each transmitted light in such transmissions to travel in parallel directions toward the user's eye. It is composed of a transmission hologram 20B. The transmission hologram 20B is formed on the surface of the spectacle lens surface 50B closer to the user's eyes (the lower surface in FIG. 8), and the reflection hologram 30B is formed on the surface of the spectacle lens surface 50B farther from the user's eyes (the lower surface in FIG. 8). upper surface). Here, an example in which both the diffractive optical system element and the direction adjusting optical system element are composed of holograms is shown, but they may be composed of laminated diffraction gratings or the like other than holograms.

For the sake of explanation, FIG. 8 shows the paths of the light C and D at the ends of the image light and their transmitted light/reflected light. The reflection hologram 30B duplicates and reflects the incident image light C into a plurality of lights C1, C2, and C3, and the transmission hologram 20B independently transmits the plurality of lights C1, C2, and C3, and upon transmission, The transmitted light CR1, CR2, CR3 is directed to the user's eye and travels in parallel directions. Similarly, the reflection hologram 30B replicates and reflects the incident image light D into a plurality of lights D1, D2, and D3, and the transmission hologram 20B independently transmits the plurality of lights D1, D2, and D3, The light DR1, DR2, and DR3 transmitted during . are directed to the user's eye in parallel directions. The above-described direction adjustment function is realized by using multiple recording of the holograms described above, as in the first mode.

As shown in FIG. 8, reflected lights CR1 and DR1 converge on the user's pupil, similarly reflected lights CR2 and DR2 converge on the pupil, and reflected lights CR3 and DR3 also converge on the pupil. A plurality of light beams duplicated as described above enter the user's pupil, and the Eyebox has a range W2 corresponding to the number of light beams arranged in parallel. Although FIG. 8 is an example, the interval W1 for arranging a plurality of lights is desirably around 2 mm in a bright environment and around 5 mm in a dark environment, and is designed so that two or more rays enter the pupil. Also, in the second mode, the technical matters described with reference to FIGS. 4 to 7 are the same as those in the first mode.

(Third aspect)
Next, the 3rd aspect is demonstrated. As shown in FIG. 9, in the third aspect, the diffractive optical system element duplicates the image light emitted from the image output unit 12 into a plurality of lights based on the waveguide method, and converts the duplicated lights into a plurality of lights as described above. A waveguide 40 that emerges toward the lens surface of the spectacles.

As shown in FIG. 10, for example, the waveguide 40 includes waveguide glass 40A and a diffractive optical element 40B. The diffractive optical element 40B reflects the incident light E, reflects it at different points, and emits it as a plurality of lights E1, E2, and E3. Similarly, the diffractive optical element 40B reflects the incident light F, reflects it at different points, and emits it as a plurality of lights F1, F2, and F3. In this way, the waveguide 40 can be used to duplicate the image light into a plurality of lights based on the waveguide method, and the duplicated lights can be emitted toward the lens surfaces of the spectacles.

FIG. 11(a) shows images of light rays emitted to the spectacle lens surface in the first to third modes. A large number of light beams shown in FIG. 11(a) are duplicated by shifting the image light in the vertical and horizontal directions by a diffractive optical element for duplicating the image light. generated. In FIG. 11A, the vertical and horizontal shift intervals are designed to be about 2 mm, for example, considering that the display is used in a bright environment.

(About effect)
According to the above-described embodiments of the invention, with a relatively simple configuration of the optical system, it is possible to adjust the directions of the image lights so that they travel in directions parallel to each other toward the eyes of the user wearing the spectacles-type image display device. It is possible to realize a wide range of Eyeboxes. Further, as described above with reference to FIG. 4A, the angle of the object light at the time of hologram creation (exposure) becomes the viewing angle at the time of reproduction, so the angle of the object light at the time of hologram creation (exposure) is adjusted. This makes it possible to widen the viewing angle during reproduction. In this way, the eyebox can be enlarged while maintaining a wide viewing angle.

The orientation adjustments described above are designed to bring more than one light beam into the user's pupil, enhancing the user's view of the image.

Further, as described above with reference to FIG. 6, blurring of the image is prevented by further providing a molding lens 61 (molding optical system element) for molding the diffused display light (reproduction light) into a narrower shape. and high resolution can be achieved.

(others)
Although the spectacles-type image display device according to one embodiment of the present invention has been described above, the configuration is not limited to the above configuration and can be changed as appropriate. The image displayed for the user may be a moving image (video) or a still image.

In addition, the number, arrangement, etc. of the optical components provided in the spectacles-type image display device should satisfy at least the configuration described in the above embodiment, and optical components different from the optical components described in the above embodiment are included in the optical path. may be provided in

For example, the control unit 13 in the glasses-type image display device 1 may function as a computer. FIG. 12 is a diagram showing an example of the hardware configuration of the control unit 13. As shown in FIG. The control unit 13 described above may be physically configured as a computer device including a processor 1001, a memory 1002, a storage 1003, a communication device 1004, an input device 1005, an output device 1006, a bus 1007, and the like. Each function in the control unit 13 is performed by loading predetermined software (program) on hardware such as the processor 1001 and the memory 1002, the processor 1001 performs calculation, communication by the communication device 1004, communication in the memory 1002 and the storage 1003 It is realized by controlling reading and/or writing of data.

Although the present invention has been described in detail above, it will be apparent to those skilled in the art that the present invention is not limited to the embodiments described herein. The present invention can be embodied in modified and varied aspects without departing from the spirit and scope of the invention defined by the claims. Accordingly, the descriptions herein are for the purpose of illustration and description, and are not intended to have any limiting meaning with respect to the present invention.

The order of processing procedures, etc. of each aspect/embodiment described herein may be interchanged as long as there is no contradiction. For example, the methods described herein present elements of the various steps in a sample order, and are not limited to the specific order presented.

Input/output information and the like may be stored in a specific location (for example, memory), or may be managed in a management table. Input/output information and the like can be overwritten, updated, or appended. The output information and the like may be deleted. The entered information and the like may be transmitted to another device.

Each aspect/embodiment described herein may be used alone, may be used in combination, or may be used by switching between implementations. In addition, notification of predetermined information (e.g., notification of "being X") is not limited to being performed explicitly, but may be performed implicitly (e.g., not notifying the predetermined information) good.

The terms explained in this specification and/or terms necessary for understanding this specification may be replaced with terms having the same or similar meanings.

In addition, the information, parameters, etc. described in this specification may be represented by absolute values, may be represented by relative values from a predetermined value, or may be represented by corresponding other information. .

The names used for the parameters above are not limiting in any way. Further, the formulas, etc. using these parameters may differ from those explicitly disclosed herein.

As used herein, the phrase "based on" does not mean "based only on," unless expressly specified otherwise. In other words, the phrase "based on" means both "based only on" and "based at least on."

Any reference to elements using the "first," "second," etc. designations used herein does not generally limit the quantity or order of those elements. These designations may be used herein as a convenient method of distinguishing between two or more elements. Thus, references to first and second elements do not imply that only two elements may be employed therein, or that the first element must precede the second element in any way.

To the extent that "including," "comprising," and variations thereof are used herein or in the claims, these terms, as well as the term "comprising," are inclusive. intended to be Furthermore, the term "or" as used in this specification or the claims is not intended to be an exclusive OR.

In this specification, plural devices shall be included unless the context or technicality clearly indicates that there is only one.

DESCRIPTION OF SYMBOLS 1... Glasses type image display apparatus 10... Image display unit 11... Content storage part 12... Image output part 13... Control part 20A, 20B... Transmission hologram 30A, 30B... Reflection hologram 40... Waveguide, 40A... waveguide glass, 40B... diffractive optical element, 50... lens, 50A... eyeglass lens surface, 50B... eyeglass lens surface, 51... bridge, 52... temple, 60... adjustment lens, 61... molding lens, 1001... Processor 1002 Memory 1003 Storage 1004 Communication device 1005 Input device 1006 Output device 1007 Bus.

Claims (1)

A spectacles-type image display device including an image output unit that emits image light, which is light containing image information, toward lens surfaces of spectacles,
a diffractive optical system element for replicating the image light emitted from the image output unit;
Each light replicated by the diffractive optical system element reacts independently, and during the reaction, each light after the reaction is directed to the eyes of the user wearing the spectacles-type image display device in parallel directions. a direction adjusting optical system element that adjusts the direction so as to advance to
with
The diffractive optical system element is provided on the lens surface of the spectacles, and is composed of a transmission hologram that replicates the image light emitted from the image output unit into a plurality of lights and transmits them,
The direction-adjusting optical system element is provided on the lens surface of the spectacles, and independently reflects the plurality of lights transmitted by the transmission hologram, and each light reflected at the time of the reflection is the spectacles-type lens. Reflection holograms oriented to travel in parallel directions toward the eyes of a user wearing the image display device,
Glasses-type image display device.

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