Light guide member, optical unit, virtual image display device, and head-mounted display

Abstract

To improve light utilization efficiency.SOLUTION: A light guide member comprises: a first light guide unit having a plurality of reflection surfaces that branches an incident light beam incident from a light incident unit into a plurality of light beams; and a second light guide unit that guides the plurality of light beams branched by the plurality of reflection surfaces and emits the light beams from a light emission unit. The plurality of reflection surfaces includes at least one first reflection surface and at least one second reflection surface. A part of the incident light beam is made incident on the first reflection surface, reflected on the first reflection surface, and guided to the second light guide unit. The second reflection surface reflects the other part of the incident light beam that is not made incident on the first reflection surface and made incident on the second reflection surface, and guides the light beam to the second light guide unit.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a light-guiding member, an optical unit, a virtual image display device, and a head-mounted display. [Background technology]

[0002] A virtual image display device is known that enlarges an image displayed on an image display element and displays the enlarged virtual image so that an observer can observe it. For example, Patent Document 1 describes a specific configuration of this type of virtual image display device.

[0003] As described in Patent Document 1, the virtual image display device is configured to cause light from an image display element (hereinafter referred to as "image light") to enter a light-guiding member, guide the incident image light using the light-guiding member, and emit the guided image light toward an observer so that the observer can observe the emitted image light as an enlarged virtual image.

[0004] The light-guiding member described in Patent Document 1 includes a plurality of partially reflective surfaces that split image light incident from a light incident portion into reflected light and transmitted light. The image light is split into a plurality of light beams by the plurality of partially reflective surfaces, and each of the split light beams is guided toward the observer's eye as light with a different angle of view. Because light with a wide angle of view reaches the observer's eye, the observer can view a virtual image with a wide angle of view. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] U.S. Patent Application Publication No. 2020 / 200963 Summary of the Invention [Problem to be solved by the invention]

[0006] In the light guide member described in Patent Document 1, the farther a partially reflective surface is located from the light incident portion, the more partially reflective surfaces the image light passes through before it is incident. Because the image light is lost each time it passes through a partially reflective surface, the amount of light that does not reach the observer's eyes increases. This reduces the light utilization efficiency of the light guide member, and the visibility of the virtual image decreases.

[0007] The present invention has been made in consideration of the above circumstances, and its object is to provide a light-guiding member, an optical unit, a virtual image display device, and a head-mounted display that can improve light utilization efficiency. [Means for solving the problem]

[0008] A light guide member according to one embodiment of the present invention includes a first light guide portion having a plurality of reflecting surfaces that split an incident light beam from a light input portion into a plurality of light beams, and a second light guide portion that guides the plurality of light beams split by the plurality of reflecting surfaces and outputs the light beams from a light output portion. The plurality of reflecting surfaces include at least one first reflecting surface and It is disposed at a position on the optical path farther from the light incident portion than the first reflecting surface. The optical element includes at least one second reflecting surface. A portion of the incident light beam is incident on the first reflecting surface, reflected by the first reflecting surface, and guided to the second light guiding section. The second reflecting surface reflects the other portion of the incident light beam that is incident on the second reflecting surface without being incident on the first reflecting surface, and guides it to the second light guiding section. [Effects of the Invention]

[0009] According to one embodiment of the present invention, it is possible to improve the light utilization efficiency in a light guide member, an optical unit, a virtual image display device, and a head-mounted display. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a schematic diagram illustrating a configuration of a head-mounted display, which is an example of a virtual image display device according to an embodiment of the present invention. [Figure 2] 1A and 1B are diagrams illustrating a configuration of a light guide member provided in a head-mounted display according to an embodiment of the present invention. [Figure 3A]1 is a schematic diagram showing a state in which a wearer wears a head-mounted display according to an embodiment of the present invention. [Figure 3B] 1 is a schematic diagram showing a state in which a wearer wears a head-mounted display according to an embodiment of the present invention. [Figure 3C] 1 is a schematic diagram showing a state in which a wearer wears a head-mounted display according to an embodiment of the present invention. [Figure 4] 10A and 10B are diagrams illustrating a configuration of a light guide member provided in a head-mounted display according to another embodiment of the present invention. [Figure 5] FIG. 2 is a diagram showing a model of a light-guiding member used in a simulation of Example 1 of the present invention. [Figure 6] FIG. 4 is a diagram showing unevenness in the amount of light in Example 1 of the present invention. [Figure 7] FIG. 10 is a diagram showing a model of a light-guiding member used in a simulation of Example 2 of the present invention. [Figure 8] FIG. 10 is a diagram showing unevenness in the amount of light in Example 2 of the present invention. [Figure 9] FIG. 10 is a diagram showing a model of a light-guiding member used in a simulation of Example 3 of the present invention. [Figure 10] FIG. 10 is a diagram showing unevenness in the amount of light in Example 3 of the present invention. [Figure 11] FIG. 10 is a diagram showing a model of a light-guiding member used in a simulation of Example 4 of the present invention. [Figure 12] FIG. 10 is a diagram showing unevenness in the amount of light in Example 4 of the present invention. [Figure 13] FIG. 10 is a diagram showing a model of a light-guiding member used in a simulation of Example 5 of the present invention. [Figure 14] FIG. 10 is a diagram showing unevenness in the amount of light in Example 5 of the present invention. [Figure 15] FIG. 13 is a diagram showing a model of a light-guiding member used in a simulation of Example 6 of the present invention. [Figure 16] FIG. 10 is a diagram showing unevenness in the amount of light in Example 6 of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0011] A light-guiding member, an optical unit, a virtual image display device, and a head-mounted display according to an embodiment of the present invention will be described below with reference to the drawings. In the following description, common or corresponding elements are denoted by the same or similar reference numerals, and redundant descriptions will be appropriately simplified or omitted.

[0012] Fig. 1 is a schematic diagram showing the configuration of a head-mounted display 1, which is an example of a virtual image display device according to this embodiment. As shown in Fig. 1, the head-mounted display 1 includes an image display element 10 and an optical unit. The optical unit includes a propagation optical system 20 and a light-guiding member 30. In Fig. 1, the symbol EY indicates the eye of a wearer (observer) wearing the head-mounted display 1.

[0013] The image display element 10 is an element that displays an image to be observed as a virtual image, and examples thereof include an OLED (Organic Light Emitting Diode) array, an LD (laser diode) array, an LED (Light Emitting Diode) array, a MEMS (Micro Electro Mechanical Systems), a DMD (Digital Micromirror Device), etc.

[0014] Light emitted from each pixel of the image display element 10 (i.e., image light) is incident on the propagation optical system 20. The propagation optical system 20 is an optical system that propagates the image light from the image display element 10, which is a light source, and makes the image light incident on the light incident section 320 of the light-guiding member 30 as parallel light.

[0015] The image light is made incident as parallel light on the light incident unit 320 by the propagation optical system 20, and the image light passes through the light guiding member 30 and is focused at a point on the retina of the wearer's eye, thereby obtaining a high-quality virtual image.

[0016] The light-guiding member 30 guides the image light incident from the propagation optical system 20 and emits it to the outside of the light-guiding member 30 toward the eye EY for displaying a virtual image. The wearer can observe the image light emitted from the light-guiding member 30 as an enlarged virtual image.

[0017] In the following description, the first horizontal direction in which the image display element 10, the propagation optical system 20, and the light-guiding member 30 are aligned is referred to as the z direction, the second horizontal direction perpendicular to the z direction is referred to as the y direction, and the vertical direction perpendicular to both the y direction and the z direction is referred to as the x direction. The mutually perpendicular X direction, Y direction, and Z direction form a right-handed system. Note that the names of the directions are used for convenience in explaining the relative positional relationships of the components, and do not indicate absolute directions. Depending on the posture of the head-mounted display 1, for example, the y direction and the z direction are not necessarily horizontal, but may be vertical.

[0018] Fig. 2 is a diagram showing the configuration of the light guide member 30. While Fig. 1 is a diagram showing the light guide member 30 as viewed from the positive side in the X direction, Fig. 2 is a diagram showing the light guide member 30 as viewed from the positive side in the Z direction (the side of the wearer's eye EY).

[0019] As shown in FIGS. 1 and 2, the light-guiding member 30 includes a first light-guiding portion 32 and a second light-guiding portion .

[0020] The first light guiding unit 32 has a light incident unit 320. Image light from the propagation optical system 20 is incident on the light incident unit 320. As shown in Fig. 1, the image light (incident light beam) incident on the light incident unit 320 is reflected by a reflecting surface 321 and propagates in the positive Y direction.

[0021] A reflecting surface 322 (third reflecting surface) is disposed inside the first light guiding unit 32. A plurality of reflecting surfaces 323 that split the image light (incident light beam) incident from the light incident unit 320 into a plurality of light beams are also disposed inside the first light guiding unit 32. The reflecting surface 322 reflects the incident light beam that is incident from the light incident unit 320 and reflected by the reflecting surface 321 toward the plurality of reflecting surfaces 323 without transmitting the incident light beam.

[0022] The multiple reflecting surfaces 323 include at least one first reflecting surface 323a and at least one second reflecting surface 323b. In the example of FIGS. 1 and 2, a total of five reflecting surfaces are included: four first reflecting surfaces 323a and one second reflecting surface 323b. In the example of FIGS. 1 and 2, the number of first reflecting surfaces 323a is greater than the number of second reflecting surfaces 323b, but the configuration of the present invention is not limited to this. A configuration in which the number of second reflecting surfaces 323b is greater than the number of first reflecting surfaces 323a is also within the scope of the present invention. Note that when the first reflecting surface 323a and the second reflecting surface 323b are not to be distinguished from each other, both the first reflecting surface 323a and the second reflecting surface 323b will be referred to as the reflecting surface 323.

[0023] By disposing the reflecting surface 322 between the light incident portion 320 and the reflecting surface 323, the degree of freedom in arranging the light incident portion 320 is improved compared to a configuration without the reflecting surface 322. For example, by devising the arrangement of the light incident portion 320, the light guide member 30 can be made more compact.

[0024] The first light guiding unit 32 has a first surface 324 and a second surface 325 that are arranged parallel to each other. The first surface 324 and the second surface 325 are surfaces that are parallel to the XY plane that extends in the X and Y directions, and are arranged perpendicular to the first reflecting surface 323a and the second reflecting surface 323b. The first reflecting surface 323a and the second reflecting surface 323b are arranged between the first surface 324 and the second surface 325.

[0025] The distance between the first surface 324 and the second surface 325 is the same as the width (dimension in the Z direction) of the first reflecting surface 323a and the second reflecting surface 323b. That is, the first reflecting surface 323a and the second reflecting surface 323b have a size that covers the entire first light guiding section 32 in the Z direction.

[0026] By adopting a configuration having first surface 324 and second surface 325 arranged parallel to each other, the incident light beam incident from light incident unit 320 can be propagated by total reflection on the pair of flat surfaces of first surface 324 and second surface 325. This is advantageous for designing first light guiding unit 32 to be thin.

[0027] Furthermore, if an incident light beam is configured to propagate by total reflection at each of two pairs of flat surfaces, for example, not only the first surface 324 and the second surface 325 but also another pair of flat surfaces, it would be difficult to process each flat surface to ensure satisfactory parallelism and surface accuracy. In this embodiment, by configuring the incident light beam to propagate by total reflection at only one pair of flat surfaces, processing is easier than a configuration in which the incident light beam is propagated by total reflection at two pairs of flat surfaces.

[0028] The first light guiding section 32 and the second light guiding section 34 are, for example, separate members. The light guiding member 30 is formed by bonding the first light guiding section 32 and the second light guiding section 34, which are separate members, together into a single unit. The first light guiding section 32 has an exit surface 326 that emits multiple light beams branched by multiple reflecting surfaces 323. The second light guiding section 34 has an incident surface 341 onto which the multiple light beams emitted from the exit surface 326 are incident. The exit surface 326 and the incident surface 341 are parallel to each other. Additionally, the exit surface 326 and the incident surface 341 are bonded together, thereby forming the first light guiding section 32 and the second light guiding section 34 as a single unit.

[0029] Because the exit surface 326 and the incident surface 341 are parallel, it is possible to suppress the occurrence of various aberrations when the light beams from the first light guiding section 32 enter the second light guiding section 34. Furthermore, by integrally forming the first light guiding section 32 and the second light guiding section 34, the exit surface 326 and the incident surface 341 do not require a large area ratio compared to a configuration in which the first light guiding section 32 and the second light guiding section 34 are arranged apart. This makes it easier to process the light guiding member 30.

[0030] The second light guiding unit 34 has two surfaces that are parallel to each other. One surface is a third surface 342 that is located on the same plane as the first surface 324. The other surface is a fourth surface 343 that is located on the same plane as the second surface 325. In the second light guiding unit 34, each light beam incident on the incident surface 341 is propagated while being totally reflected by the flat surfaces of the third surface 342 and the fourth surface 343.

[0031] A plurality of partially reflecting surfaces 344 are arranged inside the second light guiding section 34, which split each light beam incident from the incident surface 341 into reflected light and transmitted light. The plurality of partially reflecting surfaces 344 are arranged side by side at predetermined intervals in the Y direction. Each partially reflecting surface 344 is oriented so as to form a predetermined angle with respect to the third surface 342. The partially reflecting surfaces 344 are, for example, half mirrors.

[0032] Here, in the first light guiding unit 32, the multiple reflecting surfaces 323 split the incident light beam from the light incident unit 320 into multiple light beams corresponding to each angle of view in the vertical direction (X direction). Each of the multiple light beams split in the vertical direction is further split into multiple light beams corresponding to each angle of view in the horizontal direction (Y direction) by the multiple partial reflecting surfaces 344 in the second light guiding unit 34. The light beams for each angle of view after splitting in the horizontal direction are deflected by each partial reflecting surface 344 in a direction according to the arrangement angle of each partial reflecting surface 344, and are output from the third surface 342 (in other words, the light output unit). This allows the wearer to view a virtual image with a wide angle of view in both the vertical and horizontal directions.

[0033] In this way, the second light guiding section 34 is configured to guide each of the multiple light beams incident from the first light guiding section 32 using two parallel surfaces (third surface 342 and fourth surface 343), and deflect each guided light beam to emit it from the light emitting section (third surface 342).

[0034] The light guide member 30 shown in FIGS. 1 and 2 is manufactured, for example, by the following method.

[0035] A reflective surface 321 is formed on one surface of one optical block constituting the first light guiding unit 32. A reflective surface 322 is formed on a portion of one surface of one optical block constituting the first light guiding unit 32. A first reflective surface 323a is formed on a portion of one surface of each of the four optical blocks constituting the first light guiding unit 32. A second reflective surface 323b is formed on a portion of one surface of one optical block constituting the first light guiding unit 32. Each reflective surface is made of a vapor-deposited film formed by vapor-depositing a metal material, for example. Note that, to improve adhesion to the optical block, a primer layer may be formed on one surface of the optical block before the reflective surface is formed. The optical blocks on which the reflective surfaces are formed are joined together with an adhesive to complete the first light guiding unit 32, which has a reflective surface 321 and has a reflective surface 322 and multiple reflective surfaces 323 arranged therein.

[0036] Partially reflective surfaces 344 are formed on one surfaces of the plurality of optical blocks that make up the second light guiding section 34. The partially reflective surfaces 344 are also made of a vapor-deposited film formed by, for example, evaporating a metal material. The optical blocks on which the partially reflective surfaces 344 are formed are joined together with an adhesive to complete the second light guiding section 34, with the partially reflective surfaces 344 arranged therein.

[0037] Next, the light guiding member 30 is completed by bonding the exit surface 326 of the first light guiding section 32 and the incident surface 341 of the second light guiding section 34 together with an adhesive.

[0038] Each optical block of the light guiding member 30 is a molded product made of synthetic resin such as plastic, which reduces the weight of the light guiding member 30. Reducing the weight of the light guiding member 30 reduces the load on the wearer's nose, which reduces fatigue when the wearer wears the head mounted display 1 for a long period of time, for example.

[0039] 3A to 3C are schematic diagrams showing a state in which a wearer wears the head mounted display 1. The head mounted display 1 shown in Figs. 3A to 3C is sometimes called smart glasses.

[0040] The head mounted display 1 shown in FIG. 3A is a binocular type head mounted display, and is configured such that a single light guiding member 30 having a length equivalent to the width of the wearer's face is fixed to a frame 100. The light guiding member 30 forms an eye box in an area including both the left and right eyes. The image display element 10 and the propagation optical system 20 are built into, for example, temples (also called "temples") of the frame 100. The frame 100 may be shaped to cover not only both ends of the light guiding member 30, but also the upper and lower edges of the light guiding member 30.

[0041] 3B is also a binocular type head mounted display, and is configured such that a pair of head mounted displays corresponding to the left and right eyes are fixed to a frame 100. The light guiding member 30 corresponding to the right eye forms an eye box in an area including the right eye. The light guiding member 30 corresponding to the left eye forms an eye box in an area including the left eye.

[0042] 3C is a monocular head mounted display, and is configured such that a single head mounted display corresponding to the right eye is fixed to the frame 100. Note that a monocular head mounted display in which a single head mounted display corresponding to the left eye is fixed to the frame 100 also falls within the scope of the present invention.

[0043] The light guide member 30 according to this embodiment is not limited to a head-mounted display, but can also be applied to other virtual image display devices, such as a head-up display.

[0044] The first light guiding section 32 will now be described in more detail.

[0045] In the first light guiding section 32, the incident light beam incident from the light incident section 320 is reflected by the reflecting surface 322 toward the plurality of reflecting surfaces 323. Since the incident light beam is reflected without being transmitted by the reflecting surface 322, there is substantially no loss of light quantity at the reflecting surface 322.

[0046] A portion of the incident light beam reflected by reflecting surface 322 is incident on and reflected by each of first reflecting surfaces 323a, and is guided to second light guiding section 34. Another portion of the incident light beam that reaches second reflecting surface 323b without being incident on any of the other first reflecting surfaces 323a is incident on and reflected by second reflecting surface 323b, and is guided to second light guiding section 34. In this way, the incident light beam reflected by reflecting surface 322 is branched into a plurality of light beams by being incident on and reflected by each of the plurality of reflecting surfaces 323, and is guided to second light guiding section 34.

[0047] In the light guide member of the conventional configuration exemplified in Patent Document 1, the image light is incident via a larger number of partially reflective surfaces as the partially reflective surfaces are located farther from the light incident portion. Since the image light is lost each time it passes through a partially reflective surface, the amount of light that does not reach the wearer's eyes increases. As a result, the light utilization efficiency of the light guide member is low.

[0048] In contrast, in the present embodiment, a light beam with substantially no loss in light quantity is incident on the second reflecting surface 323b located away from the light entrance portion 320. Such a light beam is reflected by the second reflecting surface 323b, guided from the first light guiding portion 32 to the second light guiding portion 34, and emitted toward the wearer's eye EY. As described above, in the present embodiment, the number of times the light beam passes through the reflecting surface 323 in the light guiding member 30 is reduced compared to the conventional configuration. Since the loss in light quantity when passing through the reflecting surface 323 is reduced, the light utilization efficiency of the light guiding member 30 is improved. As a result, unevenness in the light quantity (uneven brightness of the virtual image) is reduced, and the visibility of the virtual image is improved.

[0049] The light utilization efficiency of the light guiding member 30 is indicated by the ratio (i.e., emitted light amount / incident light amount) of the amount of image light emitted from the light exit portion (third surface 342) of the second light guiding portion 34 to the amount of image light incident on the light entrance portion 320 of the first light guiding portion 32 (incident light amount). In this embodiment, the amount of light incident on the pupil of the wearer's eye EY is considered to be the emitted light amount. The pupil of the eye EY is assumed to be a circle with a radius of 3 mm.

[0050] Furthermore, when image light having a uniform light amount relative to the angle of view is incident on the light-guiding member 30, the unevenness in the amount of light (unevenness in the brightness of the virtual image) is expressed as follows using the maximum and minimum values ​​of the light amount within the angle of view of the virtual image formed on the retina of the eye EY: Light intensity unevenness = (maximum light intensity within the angle of view - minimum light intensity within the angle of view) / (maximum light intensity within the angle of view)

[0051] The light intensity unevenness is preferably 80% or less, and more preferably 40% or less. If the light intensity unevenness exceeds 80%, chipping will be visible in areas of the image with low light intensity. If the light intensity unevenness is 40% or less, the image can be viewed without any discomfort.

[0052] One of the multiple (four in this embodiment) first reflecting surfaces 323a is disposed closest on the optical path to the light incident section 320 among the multiple reflecting surfaces 323. For convenience, the first reflecting surface 323a disposed closest on the optical path to the light incident section 320 among the multiple reflecting surfaces 323 will be referred to as the "incident-side first reflecting surface 323a."

[0053] Second reflecting surface 323b is disposed at a position on the optical path farther from light incident section 320 than first reflecting surface 323a.

[0054] Here, with regard to the angle of view in the vertical direction (X direction), the angle of view of light reaching the eye EY from above the YZ plane (horizontal plane) that passes through the center of the pupil of the eye EY and extends in the Y and Z directions is defined as a positive angle of view, and the angle of view of light reaching the eye EY from below the YZ plane is defined as a negative angle of view.

[0055] Light with a field angle ranging from +n° to -n° in the vertical direction reaches the eye EY. Specifically, the light beam reflected by the incident-side first reflecting surface 323a reaches the eye EY as light with a field angle of +n° (i.e., the maximum field angle) when the position of the eye EY in the X direction is at the end of the eye box in the +X direction, and the light beam reflected by the second reflecting surface 323b reaches the eye EY as light with a field angle of -n° (i.e., the minimum field angle) when the position of the eye EY in the X direction is at the end of the eye box in the -X direction. The first reflecting surface 323a and second reflecting surface 323b that reflect light with a field angle ranging from +n° to -n° that reaches the eye EY are determined by the position of the eye EY in the eye box. For example, when the eye EY is positioned at the end of the eye box in the +X direction, light having a field angle of +n° reflected by the incident-side first reflecting surface 323a enters the eye EY, and light having a field angle of -n° reflected by a first reflecting surface 323a that is further in the -X direction than the incident-side first reflecting surface 323a (for example, the third first reflecting surface 323a in the -X direction from the incident-side first reflecting surface 323a) enters the eye EY. Similarly, when the eye EY is positioned at the end of the eye box in the -X direction, light having a field angle of -n° reflected by the second reflecting surface 323b enters the eye EY, and light having a field angle of +n° reflected by a first reflecting surface 323a that is further in the +X direction than the second reflecting surface 323b (for example, the third first reflecting surface 323a in the +X direction from the second reflecting surface 323b) enters the eye EY. The light beams reflected by each of the first reflecting surfaces 323a other than the incident-side first reflecting surface 323a reach the eye EY as light at each angle of view between the maximum angle of view and the minimum angle of view. In addition, the light beams corresponding to larger angles of view have larger angles of reflection at the reflecting surface 323. Specifically, of the light beams reaching the eye EY at a predetermined position in the eye box, the reflection angles at the incident-side first reflecting surface 323a and at first reflecting surfaces 323a closer to the incident-side first reflecting surface 323a become larger, and the reflection angles at the second reflecting surface 323b and at first reflecting surfaces 323a closer to the second reflecting surface 323b become smaller.

[0056] In this embodiment, a light beam with substantially no loss in light quantity is incident on second reflecting surface 323b located away from light incident unit 320. Therefore, the amount of light is ensured even for light at the minimum angle of view when eye EY is located at the end on the -X side of the eye box, which was a case where light quantity loss was significant in light guiding members with conventional configurations. This improves the light utilization efficiency of light guiding member 30, suppresses unevenness in light quantity due to the eye box position and angle of view, and improves the visibility of the virtual image.

[0057] When the total amount of light at each angle of view that is incident perpendicularly to incident surface 320a of light incident unit 320, reflected by each of the plurality of reflecting surfaces 323, and emitted from second light guiding unit 34 is denoted by LV, and the amount of light at the maximum angle of view that is incident perpendicularly to incident surface 320a of light incident unit 320, reflected by first reflecting surface 323a (i.e., incident-side first reflecting surface 323a) that is disposed closest to light incident unit 320 on the optical path among the plurality of reflecting surfaces 323, and emitted from second light guiding unit 34 is denoted by LV1, light guiding member 30 satisfies the following formula (1): 0.001 <LV1 / LV<0.5 Meet the following.

[0058] By satisfying the above formula (1), the light utilization efficiency of the light guide member 30 is further improved and the unevenness in the amount of light is suppressed. If LV1 / LV is 0.5 or more, the amount of light at the angle of view that is reflected by a reflecting surface other than the incident-side first reflecting surface 323a among the multiple reflecting surfaces 323 and emitted from the second light guide section 34 becomes too low, leading to a decrease in the light utilization efficiency of the light guide member 30 and unevenness in the amount of light. If LV1 / LV is 0.001 or less, the amount of light at the maximum angle of view is too low compared to the amount of light at the other angles of view, leading to a decrease in the light utilization efficiency of the light guide member 30 and unevenness in the amount of light.

[0059] At least one of the plurality of first reflecting surfaces 323a (in this embodiment, all of the plurality of first reflecting surfaces 323a) is a partially reflecting surface that transmits a portion of the light incident on the first reflecting surface 323a, such as a half mirror. At least two of the plurality of reflecting surfaces 323 have different areas.

[0060] When the area of ​​one reflecting surface (hereinafter referred to as "the reflecting surface") 323 is increased relative to the areas of the other reflecting surfaces 323, the area of ​​light reflected by the reflecting surface 323 increases, and therefore the amount of light at the corresponding angle of view in the vertical direction (X direction) (for example, the angle of view of +n° for the incident-side first reflecting surface 323a) increases relative to the amount of light at the other angles of view in the vertical direction. However, when the area of ​​the reflecting surface 323 is increased relative to the areas of the other reflecting surfaces 323, light corresponding to the other angles of view is more likely to be attenuated by being incident on the reflecting surface 323 before being incident on the other reflecting surface 323 or after being reflected by the other reflecting surface 323. Therefore, increasing the area of ​​the reflecting surface 323 does not simply increase the amount of light at the corresponding angle of view in the vertical direction.

[0061] Taking the above into consideration, the area of ​​each of the multiple reflecting surfaces 323 is set to a size that ensures sufficient brightness even when the light of the corresponding vertical angle of view is expanded horizontally (for example, when the horizontal angle of view range at that angle of view is expanded to a size sufficient to cover the width of the pupil of the eye EY and the width of the expected eyebox).

[0062] In this way, the area of ​​each of the plurality of reflecting surfaces 323 is set according to the corresponding angle of view in the vertical direction, so that the areas of at least two of the plurality of reflecting surfaces 323 are different from each other. This makes it possible to improve the light utilization efficiency of the light guide member 30 and suppress unevenness in the amount of light, and also makes it possible to reduce the size of the light guide member 30 by minimizing the area of ​​each of the plurality of first reflecting surfaces 323a, for example.

[0063] The multiple reflecting surfaces 323 are arranged parallel to one another.

[0064] By arranging multiple reflecting surfaces 323 parallel to each other, light of each field of view reflected by each reflecting surface 323 and emitted from the second light-guiding section 34 can be focused at a single point on the retina of the eye EY, thereby achieving high-quality virtual images.

[0065] When the arrangement interval of the plurality of reflecting surfaces 323 (in other words, the length of a line segment that is perpendicular to two adjacent reflecting surfaces 323 and has a starting point at an intersection with one of the two reflecting surfaces 323 and an ending point at an intersection with the other reflecting surface 323) is d, the light guide member 30 satisfies the following formula (2): 0.5mm <d<4mm Meet the following.

[0066] When the above formula (2) is satisfied, the light use efficiency of the light-guiding member 30 is improved, and the light beams at the two angles of view reflected by the two adjacent reflecting surfaces 323 and emitted from the second light-guiding section 34 reach the pupil of the eye EY in a state in which they partially overlap with each other. This reduces unevenness in the amount of light. When the arrangement distance d is 4 mm or more, the light beams at the two angles of view do not overlap with each other and reach the pupil of the eye EY in a state separated in the vertical direction (X direction). This increases unevenness in the amount of light, and the amount of light that does not reach the pupil of the eye EY increases, reducing the light use efficiency of the light-guiding member 30. When the arrangement distance d is 0.5 mm or less, the overlapping portion of the light beams at the two angles of view increases, which instead increases unevenness in the amount of light, and increases the amount of light that does not reach the pupil of the eye EY, reducing the light use efficiency of the light-guiding member 30.

[0067] By satisfying the following formula, the light utilization efficiency of the light guide member 30 can be further improved and unevenness in the amount of light can be suppressed. 1mm <d<3mm

[0068] As described above, the light guide member 30 allows the wearer to view the image light emitted from the light emitting portion (third surface 342) as a virtual image. Here, when the angle formed by the direction parallel to the direction of the virtual image corresponding to the first side direction of the image display element 10 (the short side direction of the image display element 10 in this embodiment) (i.e., the X direction) and each of the plurality of reflecting surfaces 323 is θ, the light guide member 30 has a reflectance angle θ expressed by the following formula (3): 30°<θ<60° Meet the following.

[0069] By changing the angle θ, the light utilization efficiency of the light guide member 30 can be improved and the unevenness of the amount of light can be suppressed. The area and arrangement of each reflecting surface 323 required for the purpose will change.

[0070] If the angle θ is 60° or more, the positions of the reflective surfaces 323 required to achieve the above effect may be too close to the second light guiding unit 34, and the reflective surfaces 323 may enter the field of view, for example. If the head-mounted display 1 is a see-through type head-mounted display, there is a risk that the visibility of the outside world may be reduced. Furthermore, since the area of ​​each reflective surface 323 required to achieve the above effect is too large, light corresponding to each angle of view in the first light guiding unit 32 is likely to be attenuated by being incident on more reflective surfaces 323. This reduces the light utilization efficiency of the light guiding member 30 and increases unevenness in the amount of light.

[0071] If the angle θ is 30° or less, the area of ​​the reflecting surface 323 required to achieve the above effect is too small. To ensure a wide angle of view, it is necessary to arrange more reflecting surfaces 323 inside the first light guiding unit 32. This increases the size of the light guiding member 30, making it difficult to conform to the shape of, for example, a glasses-type wearable device. Furthermore, as the number of reflecting surfaces 323 increases, light corresponding to each angle of view in the first light guiding unit 32 is more likely to be attenuated by being incident on more reflecting surfaces 323. This reduces the light utilization efficiency of the light guiding member 30 and increases unevenness in the amount of light.

[0072] Therefore, the light guide member 30 is configured to satisfy the above formula (3). By satisfying the above formula (3), it is possible to ensure visibility of the outside world and reduce the size of the light guide member 30, and also to improve the light utilization efficiency of the light guide member 30 and suppress unevenness in the amount of light.

[0073] When the number of the reflecting surfaces 323 is N, the light guide member 30 has a reflecting surface area (f) expressed by the following formula (4): 4≦N≦14 Meet the following.

[0074] By satisfying the above formula (4), the light utilization efficiency of the light-guiding member 30 can be improved and the unevenness of the amount of light can be suppressed. When the number N of the reflecting surfaces 323 is 15 or more, the overlapping portion of the light beams at the two angles of view reflected by two adjacent reflecting surfaces 323 and emitted from the second light-guiding section 34 increases, thereby increasing the unevenness of the amount of light and increasing the amount of light that does not reach the pupil of the eye EY, thereby reducing the light utilization efficiency of the light-guiding member 30. Furthermore, since the arrangement interval d becomes narrow, the required arrangement accuracy of the reflecting surfaces 323 becomes high, making processing difficult. When the number N of the reflecting surfaces 323 is 3 or less, the light beams at the two angles of view do not overlap each other and reach the pupil of the eye EY separated in the vertical direction (X direction). Therefore, the unevenness of the amount of light increases, and the amount of light that does not reach the pupil of the eye EY increases, thereby reducing the light utilization efficiency of the light-guiding member 30.

[0075] By satisfying the following formula, the light utilization efficiency of the light guide member 30 can be further improved and unevenness in the amount of light can be suppressed. 6≦N≦10

[0076] When the reflectance of the incident-side first reflecting surface 323a, which is arranged closest to the light incident unit 320 on the optical path among the plurality of reflecting surfaces 323, is R1 when the incident angle of the incident light beam to the incident-side first reflecting surface 323a is 45°, the light-guiding member 30 satisfies the following formula (5): 5% <R1<40% Meet the following.

[0077] By satisfying the above formula (5), unevenness in the amount of light is further suppressed. If the reflectance R1 is 40% or more, a sufficient amount of light is not incident on the reflecting surfaces 323 other than the incident-side first reflecting surface 323a, which are located away from the light incident section 320, making it difficult to suppress unevenness in the amount of light. If the reflectance R1 is 5% or less, the amount of light within the angle of view that is reflected by the incident-side first reflecting surface 323a and emitted from the second light guiding section 34 is small, making it difficult to improve the light utilization efficiency of the light guiding member 30.

[0078] The plurality of first reflecting surfaces 323a include a first partially reflecting surface and a second partially reflecting surface disposed at a position on the optical path farther from light incident section 320 than the first partially reflecting surface (for example, incident-side first reflecting surface 323a and a reflecting surface 323 disposed at a position on the optical path farther from light incident section 320 than incident-side first reflecting surface 323a). The reflectance when the incident angle of the incident light beam to the second partially reflecting surface is 45° is higher than the reflectance when the incident angle of the incident light beam to the first partially reflecting surface is 45°. As a more detailed example, in light-guiding member 30, the farther a first reflecting surface 323a is disposed on the optical path from light incident section 320, the higher the reflectance when the incident angle of the incident light beam is 45°.

[0079] The farther the first reflecting surface 323a is located on the optical path from the light incident unit 320, the smaller the amount of incident light beam because it is affected by light attenuation caused by the incident light beam being incident on other first reflecting surfaces 323a. Therefore, if the reflectance of all the first reflecting surfaces 323a is the same, the amount of light at the angle of view that is reflected by the first reflecting surface 323a located on the optical path farther from the light incident unit 320 and emitted from the second light guiding unit 34 will be smaller, and unevenness in the amount of light will be likely to occur. Therefore, by setting the reflectance of the first reflecting surface 323a as described above, the difference in the amount of light at each angle of view is reduced, and unevenness in the amount of light can be suppressed.

[0080] The second reflecting surface 323b may be a partially reflecting surface like the first reflecting surface 323a, but more preferably, the second reflecting surface 323b may be a reflecting surface that does not transmit incident light.

[0081] Specifically, if second reflecting surface 323b, which is disposed at a position on the optical path farther from light incident unit 320 than first reflecting surface 323a, is made a partially reflecting surface, light transmitted through second reflecting surface 323b becomes stray light, increasing the amount of light that does not reach the pupil of eye EY and reducing the light utilization efficiency of light-guiding member 30. Therefore, second reflecting surface 323b is preferably a reflecting surface that does not transmit light incident on second reflecting surface 323b, rather than a partially reflecting surface. By eliminating light that transmits through second reflecting surface 323b, the generation of stray light can be prevented, and the light utilization efficiency of light-guiding member 30 can be improved.

[0082] FIG. 4 is a diagram illustrating the configuration of a light-guiding member 30 according to another embodiment. In the above embodiment, each reflecting surface 323 is oriented to reflect the incident light beam from the reflecting surface 322 toward the positive side in the Y direction. In contrast, in another embodiment, each reflecting surface 323 is oriented to reflect the incident light beam from the reflecting surface 322 toward the negative side in the Y direction. Therefore, in this embodiment, the second light-guiding section 34 is arranged adjacent to the first light-guiding section 32 on the negative side in the Y direction. In this way, by changing the orientation of the reflecting surface 323, the position of the second light-guiding section 34 relative to the first light-guiding section 32 can be changed. In this way, there is a degree of freedom in the configuration of the light-guiding member 30, and various design modifications are possible.

[0083] Next, specific examples 1 to 6 of the head mounted display 1 will be shown. Examples 1 to 6 show the results of simulations performed on optical simulation software. The common features of Examples 1 to 6 are as follows. Note that in Examples 1 to 6, the refractive index refers to the refractive index of the d-line (wavelength 587.56 nm).

[0084] <<Common features of Examples 1 to 6>> ●Image display element 10 ◆Vertical (X) angle of view 20° ◆ Effective pixel area (display area that emits image light) 0.01mm (short side direction (X direction)) x 0.76mm (long side direction (Y direction)) ● Propagation optical system 20 (set as an ideal lens in the simulation) ◆Focal length 2.13mm The distance between the final lens surface (the lens surface closest to the light incident section 320 among the lens surfaces included in the propagation optical system 20) and the light incident section 320 1.3mm ◆ Diameter of the light beam emitted from the propagation optical system 20 4mm (However, in Examples 4 to 6, the thicknesses were 3.3 mm, 2 mm, and 5 mm, respectively.) Refractive index 1.533 (Material: Zeonex (registered trademark) E48R) Light guide member 30 Refractive index of the first light guide section 32 and the second light guide section 34 1.533 (Material: Zeonex (registered trademark) E48R) Refractive index of the adhesive that bonds the first light guide section 32 and the second light guide section 34 1.533 ●Eye Box 6mm or more in the vertical direction (X direction) ●Eye relief 15mm or more ●Eye EY (set as ideal lens in simulation) ◆Focal length 12mm ◆ Lens radius (pupil radius) 3mm

[0085] In Examples 1 to 6, the closer the reflecting surfaces 323 are to the light incident section 320 on the optical path, the smaller the natural number n is associated with them. For example, in Example 1, seven reflecting surfaces 323 are arranged inside the first light guide section 32. Therefore, in Example 1, the reflecting surfaces 323 are denoted by symbols R1, R2, R3, R4, R5, R6, and R7 in order of reflectance from the reflecting surfaces 323 arranged closest to the light incident section 320 on the optical path. In addition, the arrangement distance d between two adjacent reflecting surfaces 323 is represented by an arrangement distance d(n, n+1). As an example, the arrangement distance d between the incident-side first reflecting surface 323a arranged closest to the light incident section 320 on the optical path and the reflecting surface 323 arranged second closest to the light incident section 320 on the optical path is represented by an arrangement distance d(1, 2).

[0086] In Examples 1 to 6, among the reflecting surfaces 323 arranged inside the first light guiding section 32, the reflecting surface 323 arranged at a position on the optical path farthest from the light incident section 320 is the second reflecting surface 323b, and the other reflecting surfaces 323 are the first reflecting surfaces 323a.

[0087] [Example 1] FIG. 5 is a diagram showing a model of the light-guiding member 30 used in the simulation of Example 1. FIG. 6 is a graph showing the relationship between the position of the virtual image on the retina of the eye EY and the illuminance calculated in the simulation of Example 1, and shows the unevenness of the amount of light. The vertical axis shows the position (unit: mm) on the retina in the vertical direction (X direction), and the horizontal axis shows the illuminance (unit: W / mm 2 6 shows light that is reflected by the partially reflecting surface 344a (see FIG. 5) located in front of the center of the pupil of the eye EY, exits from the light exit part (third surface 342), and reaches the retina.

[0088] Generally, the light utilization efficiency of the light guide member of a head-mounted display is less than 10%. In contrast, in Example 1, the light utilization efficiency of the light guide member 30 is 18%, which indicates that high light utilization efficiency is achieved. Furthermore, as shown in FIG. 6, the unevenness in the amount of light is suppressed to 30%. Therefore, the wearer can view the virtual image without feeling any discomfort.

[0089] The specific numerical configuration of the head mounted display 1 according to Example 1 is as follows. As shown in the specific numerical configuration, all of the formulas (1) to (5) are satisfied in Example 1. Therefore, in Example 1, all of the effects achieved by satisfying the formulas (1) to (5) are achieved.

[0090] ●First light guide section 32 ◆Thickness (Z direction dimension) 2.5mm ◆Length (Y direction dimension) 37mm ◆Width (X-direction dimension) 15mm The angle between the incident surface 320a of the light incident portion 320 and the reflecting surface 321 26.5° The angle that the reflecting surface 322 makes with respect to the vertical direction (X direction) 40° ◆Reflective surface 323 ▼Number of sheets 7 lenses (all partially reflective) ▼Angle θ 40° ▼Reflectivity at an incident angle of 45° R1: 14.3% R2: 16.7% R3: 15% R4: 23% R5: 25% R6: 25% R7: 32% ▼LV1 / LV 0.12 ▼Placement interval d d(1,2): 2.5mm d(2,3):2.45mm d(3,4):2.55mm d(4,5):2.72mm d(5,6):2.87mm d(6,7): 2.9mm ●Second light guide section 34 ◆Thickness (Z direction dimension) 2.5mm ◆Length (Y direction dimension) 37mm ◆Width (X-direction dimension) 27mm The angle between the light exit portion (third surface 342) and the partially reflecting surface 344 26.5°

[0091] [Example 2] Fig. 7 and Fig. 8 are similar to Fig. 5 and Fig. 6, respectively. Specifically, Fig. 7 is a diagram showing a model of the light guiding member 30 used in the simulation of Example 2. Fig. 8 is a graph showing the relationship between the position of the virtual image on the retina of the eye EY and the illuminance calculated in the simulation of Example 2, and shows unevenness in the amount of light.

[0092] In Example 2, the light utilization efficiency of the light guide member 30 is 33%, which indicates that high light utilization efficiency is achieved. Furthermore, as shown in FIG. 8, the unevenness in the amount of light is suppressed to 20%. Therefore, the wearer can view the virtual image without feeling any discomfort.

[0093] The specific numerical configuration of the head mounted display 1 according to Example 2 is as follows. As shown in the specific numerical configuration, all of the formulas (1) to (5) are satisfied in Example 2. Therefore, in Example 2, all of the effects achieved by satisfying the formulas (1) to (5) are achieved.

[0094] ●First light guide section 32 ◆Thickness (Z direction dimension) 2.5mm ◆Length (Y direction dimension) 37mm ◆Width (X-direction dimension) 13mm The angle between the incident surface 320a of the light incident portion 320 and the reflecting surface 321 26.5° The angle that the reflecting surface 322 makes with respect to the vertical direction (X direction) 45° ◆Reflective surface 323 ▼Number of sheets 7 lenses (6 of which are partially reflective) ▼Angle θ 45° ▼Reflectivity at an incident angle of 45° R1: 20% R2: 30% R3: 40% R4: 50% R5: 60% R6: 70% R7: 100% (non-partially reflective surface) ▼LV1 / LV 0.14 ▼Placement interval d d(1,2):2.15mm d(2,3): 2.2mm d(3,4):2.55mm d(4,5):2.17mm d(5,6): 2.1mm d(6,7):2.95mm ●Second light guide section 34 ◆Thickness (Z direction dimension) 2.5mm ◆Length (Y direction dimension) 37mm ◆Width (X-direction dimension) 27mm The angle between the light exit portion (third surface 342) and the partially reflecting surface 344 26.5°

[0095] [Example 3] Fig. 9 and Fig. 10 are similar to Fig. 5 and Fig. 6, respectively. Specifically, Fig. 9 is a diagram showing a model of the light-guiding member 30 used in the simulation of Example 3. Fig. 10 is a graph showing the relationship between the position of the virtual image on the retina of the eye EY and the illuminance calculated in the simulation of Example 3, and shows unevenness in the amount of light.

[0096] In Example 3, the light utilization efficiency of the light guide member 30 is 23%, which indicates that high light utilization efficiency is achieved. Furthermore, as shown in Fig. 10, the unevenness in the amount of light is suppressed to 30%. Therefore, the wearer can view the virtual image without feeling any discomfort.

[0097] The specific numerical configuration of the head mounted display 1 according to Example 3 is as follows. As shown in the specific numerical configuration, all of the formulas (1) to (5) are satisfied in Example 3. Therefore, in Example 3, all of the effects achieved by satisfying the formulas (1) to (5) are achieved.

[0098] ●First light guide section 32 ◆Thickness (Z direction dimension) 2.5mm ◆Length (Y direction dimension) 37mm ◆Width (X-direction dimension) 13mm The angle between the incident surface 320a of the light incident portion 320 and the reflecting surface 321 26.5° The angle that the reflecting surface 322 makes with respect to the vertical direction (X direction) 55° ◆Reflective surface 323 ▼Number of sheets 7 lenses (all partially reflective) ▼Angle θ 55° ▼Reflectivity at an incident angle of 45° R1: 16.5% R2: 19.5% R3: 20% R4: 30% R5: 32.6% R6: 35% R7: 50% ▼LV1 / LV 0.16 ▼Placement interval d d(1,2): 1.7mm d(2,3): 2.1mm d(3,4): 2.0mm d(4,5): 2.2mm d(5,6):1.95mm d(6,7): 1.8mm ●Second light guide section 34 ◆Thickness (Z direction dimension) 2.5mm ◆Length (Y direction dimension) 37mm ◆Width (X-direction dimension) 27mm The angle between the light exit portion (third surface 342) and the partially reflecting surface 344 26.5°

[0099] [Example 4] Fig. 11 and Fig. 12 are similar to Fig. 5 and Fig. 6, respectively. Specifically, Fig. 11 is a diagram showing a model of the light-guiding member 30 used in the simulation of Example 4. Fig. 12 is a graph showing the relationship between the position of the virtual image on the retina of the eye EY and the illuminance calculated in the simulation of Example 4, and shows unevenness in the amount of light.

[0100] In Example 4, the light utilization efficiency of the light guide member 30 is 23%, which indicates that high light utilization efficiency is achieved. Furthermore, as shown in Fig. 12, the unevenness in the amount of light is suppressed to 40%. Therefore, the wearer can view the virtual image without feeling any discomfort.

[0101] The specific numerical configuration of the head mounted display 1 according to Example 4 is as follows. As shown in the specific numerical configuration, all of the formulas (1) to (5) are satisfied in Example 4. Therefore, in Example 4, all of the effects achieved by satisfying the formulas (1) to (5) are achieved.

[0102] ●First light guide section 32 ◆Thickness (Z direction dimension) 2.5mm ◆Length (Y direction dimension) 37mm ◆Width (X-direction dimension) 13mm The angle between the incident surface 320a of the light incident portion 320 and the reflecting surface 321 23° The angle that the reflecting surface 322 makes with respect to the vertical direction (X direction) 40° ◆Reflective surface 323 ▼Number of sheets 8 lenses (all partially reflective) ▼Angle θ 40° ▼Reflectivity at an incident angle of 45° R1: 12% R2: 15% R3: 23% R4: 25% R5: 28% R6: 30% R7: 32% R8: 50% ▼LV1 / LV 0.23 ▼Placement interval d d(1,2): 2.1mm d(2,3):2.35mm d(3,4):2.45mm d(4,5):2.75mm d(5,6):2.75mm d(6,7): 2.1mm d(7,8): 2.1mm ●Second light guide section 34 ◆Thickness (Z direction dimension) 2.5mm ◆Length (Y direction dimension) 37mm ◆Width (X-direction dimension) 27mm The angle between the light exit portion (third surface 342) and the partially reflecting surface 344 23°

[0103] [Example 5] Fig. 13 and Fig. 14 are similar to Fig. 5 and Fig. 6, respectively. Specifically, Fig. 13 is a diagram showing a model of the light-guiding member 30 used in the simulation of Example 5. Fig. 14 is a graph showing the relationship between the position of the virtual image on the retina of the eye EY and the illuminance calculated in the simulation of Example 5, and shows unevenness in the amount of light.

[0104] In Example 5, the light utilization efficiency of the light guiding member 30 is 30%, which indicates that high light utilization efficiency is achieved. Furthermore, as shown in Fig. 14, the unevenness in the amount of light is reduced by 40%. Therefore, the wearer can view the virtual image without feeling any discomfort.

[0105] The specific numerical configuration of the head mounted display 1 according to the fifth embodiment is as follows. As shown in the specific numerical configuration, all of the formulas (1) to (5) are satisfied in the fifth embodiment. Therefore, in the fifth embodiment, all of the effects achieved by satisfying the formulas (1) to (5) are achieved.

[0106] ●First light guide section 32 ◆Thickness (Z direction dimension) 1.5mm ◆Length (Y direction dimension) 37mm ◆Width (X-direction dimension) 14mm The angle between the incident surface 320a of the light incident portion 320 and the reflecting surface 321 22° The angle that the reflecting surface 322 makes with respect to the vertical direction (X direction) 40° ◆Reflective surface 323 ▼Number of sheets 12 lenses (all partially reflective) ▼Angle θ 40° ▼Reflectivity at an incident angle of 45° R1: 10% R2: 15% R3: 20% R4: 23% R5: 25% R6: 27% R7: 28% R8: 32% R9: 35% R10:35% R11:40% R12: 50% ▼LV1 / LV 0.01 ▼Placement interval d d(1,2): 1.4mm d(2,3):1.15mm d(3,4): 1.4mm d(4,5): 1.3mm d(5,6):1.55mm d(6,7):1.45mm d(7,8):1.45mm d(8,9): 1.7mm d(9,10): 1.7mm d(10,11): 1.8mm d(11,12): 1.7mm ●Second light guide section 34 ◆Thickness (Z direction dimension) 1.5mm ◆Length (Y direction dimension) 37mm ◆Width (X-direction dimension) 27mm The angle between the light exit portion (third surface 342) and the partially reflecting surface 344 22°

[0107] [Example 6] Fig. 15 and Fig. 16 are similar to Fig. 5 and Fig. 6, respectively. Specifically, Fig. 15 is a diagram showing a model of the light-guiding member 30 used in the simulation of Example 6. Fig. 16 is a graph showing the relationship between the position of the virtual image on the retina of the eye EY and the illuminance calculated in the simulation of Example 6, and shows unevenness in the amount of light.

[0108] In Example 6, the light utilization efficiency of the light guide member 30 is 23%, which indicates that high light utilization efficiency is achieved. Furthermore, as shown in FIG. 16, the unevenness in the amount of light is suppressed to 80%. Therefore, although the wearer can observe unevenness in the image, image chipping is not visible. In other words, a good image can be displayed in Example 6 as well.

[0109] The specific numerical configuration of the head mounted display 1 according to Example 6 is as follows. As shown in the specific numerical configuration, all of the formulas (1) to (5) are satisfied in Example 6. Therefore, in Example 6, all of the effects achieved by satisfying the formulas (1) to (5) are achieved.

[0110] ●First light guide section 32 ◆Thickness (Z direction dimension) 3.5mm ◆Length (Y direction dimension) 37mm ◆Width (X-direction dimension) 12mm The angle between the incident surface 320a of the light incident portion 320 and the reflecting surface 321 26.5° The angle that the reflecting surface 322 makes with respect to the vertical direction (X direction) 40° ◆Reflective surface 323 ▼Number of sheets 5 lenses (4 of which are partially reflective) ▼Angle θ 55° ▼Reflectivity at an incident angle of 45° R1: 10% R2: 15% R3: 40% R4: 20% R5: 100% (non-partially reflective surface) ▼LV1 / LV 0.19 ▼Placement interval d d(1,2):2.7mm d(2,3):2.9mm d(3,4):3.4mm d(4,5):3.1mm ●Second light guide section 34 ◆Thickness (Z direction dimension) 3.5mm ◆Length (Y direction dimension) 37mm ◆Width (X-direction dimension) 27mm The angle between the light exit portion (third surface 342) and the partially reflecting surface 344 26.5°

[0111] The above is a description of exemplary embodiments of the present invention. The embodiments of the present invention are not limited to those described above, and various modifications are possible within the scope of the technical concept of the present invention. For example, the embodiments of the present application also include appropriate combinations of embodiments explicitly shown in the specification or obvious embodiments. [Explanation of symbols]

[0112] 1: Head-mounted display 10: Image display element 20: Propagation optical system 30: Light guide member 32: 1st light guide part 34:Second light guide part 320: Light incidence part 323a: 1st reflective surface 323b: 2nd reflective surface

Claims

1. a first light guide portion having a plurality of reflecting surfaces for splitting an incident light beam incident from a light incident portion into a plurality of light beams; a second light guiding section that guides the plurality of light beams branched by the plurality of reflecting surfaces and outputs the light beams from a light emitting section, the plurality of reflecting surfaces include at least one first reflecting surface and at least one second reflecting surface that is disposed at a position farther from the light incident portion on the optical path than the first reflecting surface, a part of the incident light beam is incident on the first reflecting surface, is reflected by the first reflecting surface, and is guided to the second light guiding section; the second reflecting surface reflects another part of the incident light beam that is incident on the second reflecting surface without being incident on the first reflecting surface, and guides the reflected light to the second light guiding section. Light-guiding member.

2. the first light guiding section has a first surface and a second surface that are orthogonal to the first reflecting surface and the second reflecting surface and are arranged parallel to each other, the first reflecting surface and the second reflecting surface are disposed between the first surface and the second surface; The light guide member according to claim 1 .

3. one first reflecting surface of the at least one first reflecting surface is disposed closest to the light incident portion on the optical path among the plurality of reflecting surfaces; The light guide member according to claim 1 or 2.

4. When the total amount of light that is incident perpendicularly to the incident surface of the light incident unit, reflected by each of the plurality of reflecting surfaces, and emitted from the second light guiding unit is LV, and the amount of light that is incident perpendicularly to the incident surface of the light incident unit, reflected by a first reflecting surface that is disposed closest to the light incident unit on the optical path among the plurality of reflecting surfaces, and emitted from the second light guiding unit is LV1, the following formula can be used: 0.001<LV1 / LV<0.5 fulfill, The light guide member according to claim 1 .

5. a third reflecting surface; the third reflecting surface reflects the incident light beam toward the plurality of reflecting surfaces without transmitting the incident light beam; The light guide member according to claim 1 .

6. At least one of the first reflecting surfaces is a partially reflecting surface that transmits a portion of the light incident on the first reflecting surface, At least two of the plurality of reflecting surfaces have different areas. The light guide member according to claim 1 .

7. At least one of the first reflecting surfaces is a partially reflecting surface that transmits a portion of the light incident on the first reflecting surface, The plurality of reflecting surfaces are arranged parallel to one another. The light guide member according to claim 1 .

8. When the arrangement interval of the plurality of reflecting surfaces is d, the following formula is obtained. 0.5mm<d<4mm fulfill, The light guide member according to claim 7 .

9. the incident light beam is image light from an image display element, the light guide member allows the image light emitted from the light emitting portion to be viewed as a virtual image; When an angle formed by a direction parallel to the direction of the virtual image corresponding to the first side direction of the image display element and each of the plurality of reflecting surfaces is θ, the following equation is satisfied: 30°<θ<60° fulfill, The light guide member according to claim 1 .

10. When the number of the plurality of reflecting surfaces is N, the following formula is obtained. 4≦N≦14 fulfill, The light guide member according to claim 1 .

11. The reflectance of a first reflecting surface that is disposed closest to the light incident portion on the optical path among the plurality of reflecting surfaces is R1, where R1 is the reflectance when the incident angle of the incident light beam to the first reflecting surface is 45°, and the reflectance is expressed by the following formula: 5%<R1<40% fulfill, The light guide member according to claim 1 .

12. the first light guiding section has a plurality of the first reflecting surfaces, the plurality of first reflecting surfaces are partially reflecting surfaces that transmit a part of the light incident on the first reflecting surfaces, the plurality of first reflecting surfaces include a first partially reflecting surface and a second partially reflecting surface disposed at a position on the optical path farther from the light incident portion than the first partially reflecting surface, the reflectance when the incident angle of the incident light beam on the second partially reflective surface is 45° is higher than the reflectance when the incident angle of the incident light beam on the first partially reflective surface is 45°; The light guide member according to claim 1 .

13. the second reflecting surface does not transmit light incident on the second reflecting surface; The light guide member according to claim 1 .

14. the second light guiding section guides each of the plurality of light beams incident from the first light guiding section by two surfaces parallel to each other, and deflects each of the guided light beams to emit them from the light emitting section; The light guide member according to claim 1 .

15. the first light guiding portion and the second light guiding portion are separate members, the first light guiding section has an exit surface from which the plurality of light beams exit, the second light guiding section has an incident surface onto which the plurality of light beams emitted from the exit surface are incident, the exit surface of the first light guiding section and the entrance surface of the second light guiding section are parallel to each other; The light guide member according to claim 1 .

16. The light guide member according to any one of claims 1 to 15; an optical system that causes light from a light source to be incident as parallel light on the light incident portion of the light guide member, Optical unit.

17. an image display element for displaying an image; and the optical unit according to claim 16, the optical system causes image light from the image display element to be incident on the light incident portion of the light guide member; Virtual image display device.

18. an image display element for displaying an image; and the optical unit according to claim 16, the optical system causes image light from the image display element to be incident on the light incident portion of the light guide member; Head-mounted display.

Images