JP2016033867A - Optical member, illumination unit, wearable display, and image display apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an illumination unit that is made compact, an optical member for use therein, and a wearable display fabricated therewith.SOLUTION: An illumination unit according to the present technique is an illumination unit which can supply a light modulation element with light, the illumination unit having a light source and an optical member. The optical member has an incidence part which incident light from the light source enters, an outgoing part, and a curved surface part that internally reflects the incident light toward the outgoing part for light focusing, is formed of translucent material, and is disposed between the light source and the light modulation element.SELECTED DRAWING: Figure 2

Description

  The present technology relates to an optical member, an illumination unit using the optical member, a wearable display, and an image display device.

  2. Description of the Related Art A head mounted display (HMD) is known that is mounted on a user's head and can present an image to the individual user with a display or the like disposed in front of the eyes.

  Patent Document 1 discloses a virtual image display device used for a head mounted display or the like. The virtual image display device includes an illumination light source, a light pipe, and an image display element. The light emitted from the illumination light source is transmitted to the light pipe and enters the image display element. The display light emitted from the image display element enters the light guide plate, and is configured to enter the observer's pupil by repeating total reflection inside the light guide plate.

JP 2006-350129 A

  In wearable devices such as a head-mounted display, reduction in size and weight is required in order to reduce the burden on the user who wears the device. Therefore, there is an increasing demand for miniaturization of virtual image display devices used in these devices.

  In view of the circumstances as described above, an object of the present technology is to provide a lighting unit configured in a small size, an optical member used therefor, a wearable display using the same, and an image display device.

In order to achieve the above object, an illumination unit according to the present technology is an illumination unit capable of supplying light to a light modulation element, and includes a light source and an optical member.
The optical member includes an incident portion where light is incident from the light source, an exit portion, and a curved surface portion capable of condensing the incident light toward the exit portion by internally reflecting the incident light. The light-transmitting material is disposed between the light source and the light modulation element.

  According to the illumination unit, since the curved surface portion of the optical member has a light collecting function, the secondary light source can be formed by the optical member. As a result, the optical path length from the light source to the light modulation element can be shortened, the size can be reduced, and the number of components can be reduced.

  Further, the curved surface portion may have a reflective film on which a reflective surface is formed.

  As a result, the curved surface portion can be configured without considering the total reflection condition, and the degree of freedom in optical design can be increased.

  Specifically, the curved surface portion may include a free curved surface.

  Thereby, the freedom degree in optical design can be raised more and it becomes easy to form a desired secondary light source.

The incident part is
An incident surface;
You may have the light source expansion part which can spread the light beam emitted from the said light source toward the said curved surface part from the said entrance plane.

  The apparent size of the light source can be enlarged by the light source enlargement unit.

The optical member further includes a main body including the curved surface portion and the emitting portion,
The light source enlarging part may be formed integrally with the main body part.

  Thereby, the position accuracy of the light source enlargement portion relative to the main body portion can be increased, and desired optical characteristics can be maintained over a long period of time.

  The curved surface portion includes a first curvature in a first region where the first light beam spread along the first axial direction is reflected, and a second axial direction orthogonal to the first axial direction. And a second curvature of the second region in which the second light beam spread along the line is reflected.

  This makes it possible to emit desired illumination light in view of the aspect ratio of the light modulation element and other characteristics of the image display device.

  In this case, for example, the first curvature may be smaller than the second curvature.

The first curvature is a curvature capable of reflecting the first light flux as telecentric illumination light.
The second curvature may be a curvature capable of reflecting the second light flux as non-telecentric illumination light.

  As a result, when the illumination unit emits illumination light to a virtual image optical unit including, for example, a hologram grating and a light guide plate, illumination light suitable for the light guide characteristics of the image light in the light guide plate is formed. can do.

  Moreover, the said translucent material may contain the thermoplastic resin.

  Thereby, an optical member can be easily formed by various molding methods.

An optical member according to the present technology is an optical member made of a translucent material capable of supplying light emitted from a light source to a light modulation element, and includes an incident portion, an emission portion, and a curved surface Part.
The incident part has an incident surface on which a light beam emitted from the light source is incident and a light source enlarging part capable of expanding the light beam, and light is incident from the light source.
The curved surface portion is configured to be capable of condensing the incident light by internally reflecting the incident light toward the emitting portion.

Furthermore, the wearable display according to the present technology includes an illumination unit, a light modulation element, and a virtual image optical unit.
The illumination unit includes a light source and an optical member.
The optical member includes an incident portion where light is incident from the light source, an exit portion, and a curved surface portion capable of condensing the incident light toward the exit portion by internally reflecting the incident light. The light-transmitting material is disposed between the light source and the light modulation element.
The light modulation element modulates light emitted from the illumination unit.
The virtual image optical unit generates a virtual image of image light from the light modulation element.

Alternatively, the image display device according to the present technology includes an illumination unit, a light modulation element, and a virtual image optical unit.
The illumination unit includes a light source and an optical member.
The optical member includes an incident portion where light is incident from the light source, an exit portion, and a curved surface portion capable of condensing the incident light toward the exit portion by internally reflecting the incident light. The light-transmitting material is disposed between the light source and the light modulation element.
The light modulation element modulates light emitted from the illumination unit.
The virtual image optical unit generates a virtual image of image light from the light modulation element.

As described above, according to the present technology, it is possible to provide a lighting unit configured in a small size, an optical member used in the lighting unit, and a wearable display and an image display device using them.
Note that the effects described here are not necessarily limited, and may be any of the effects described in the present disclosure.

It is a typical top view showing some wearable displays concerning one embodiment of this art. It is sectional drawing which looked at the principal part of FIG. 1 from the X-axis direction. It is sectional drawing which looked at the principal part of FIG. 1 from the Y-axis direction. It is a typical top view which shows the light modulation element of the said wearable display. It is a top view of the principal part of the virtual image optical unit of the said wearable display, and is the figure seen from the image display unit side in the Z-axis direction. It is sectional drawing of the optical member of the said wearable display. A and B are perspective views of the optical member, and C is a plan view of the optical member. It is a figure which shows the relationship between the curvature in the curved surface part of the said optical member, and a light beam, A is sectional drawing seen from the Y-axis direction, B is sectional drawing seen from the X-axis direction. It is sectional drawing which shows the other Example of the said optical member. It is sectional drawing which shows the illumination unit which concerns on the reference example of the said embodiment. It is a perspective view which shows the optical member which concerns on the modification of the said embodiment.

  Hereinafter, embodiments according to the present technology will be described with reference to the drawings.

(Wearable display overall configuration)
FIG. 1 is a schematic plan view showing a part of a wearable display according to an embodiment of the present technology. In the figure, the X-axis, Y-axis, and Z-axis directions indicate three mutually orthogonal directions, the X-axis direction indicates a horizontal direction (left-right direction), and the Y-axis direction indicates a vertical direction (up-down direction).

  The wearable display 100 is a glasses-type display that can be worn on the head, and FIG. The wearable display 100 includes an illumination unit 110, an image display unit 120, and a virtual image optical unit 130.

  The light guide plate 133 of the virtual image optical unit 130 is configured to be held in front of the wearer's wearer's eye by a temple-shaped wearing tool, a frame, or the like. On the other hand, the illumination unit 110 and the image display unit 120 are disposed, for example, inside a housing formed on the mounting tool.

(Configuration of lighting unit)
FIG. 2 is a cross-sectional view of the main part of FIG. 1 viewed from the X-axis direction. In the figure, the position of the pupil is schematically represented. The illumination unit 110 includes a light source 111, an optical member 10, a polarizing plate 112, and a diffusion plate 113, and is configured to be able to supply light to a light modulation element 122 described later.

  Although the light source 111 is comprised by LED (Light Emitting Diode), for example, illuminations, such as a laser semiconductor and EL (Electro-Luminescence), may be used. The light source 111 can be, for example, a rectangular surface light source. The light source may be composed of a plurality of color light sources such as RGB.

  The optical member 10 is configured to be able to form a secondary light source of the light source 111 by bending light emitted from the light source 111 toward the image display unit 120 and condensing the reflected light. The optical member 10 is disposed between the light source 111 and the light modulation element 122, and is disposed between the light source 111 and the polarizing plate 112 in the present embodiment. The detailed configuration of the optical member 10 will be described later.

  The polarizing plate 112 is a plate-like element that allows only a specific polarized component (for example, a p-polarized component or an s-polarized component) out of the light emitted from the optical member 10 to pass therethrough.

  The diffusion plate 113 is a plate-like element that diffuses light emitted from the polarizing plate 112 and suppresses uneven illuminance. As the material of the diffusion plate 113, a transparent material such as transparent resin, glass, ceramics, or the like is used. As the transparent resin, for example, polycarbonate, PET (polyethylene terephthalate), or the like is used.

(Configuration of image display unit)
FIG. 3 is a cross-sectional view of the main part of FIG. 1 viewed from the Y-axis direction. Also in the figure, the position of the pupil is schematically represented. As shown in FIGS. 2 and 3, the image display unit 120 includes a polarization beam splitter (PBS) 121 and a light modulation element 122.

  The polarization beam splitter 121 is an element that selectively transmits a specific polarization component (for example, P polarization component) and selectively reflects the other polarization component (for example, S polarization component). Thereby, the illumination light (for example, S polarization component) from the illumination unit 110 is selectively reflected and enters the light modulation element 122, and the image light L (for example, P polarization component) emitted from the light modulation element 122 is reflected. The light can be selectively transmitted and can enter the collimating optical system 131 of the virtual image optical unit 130.

  The polarization beam splitter 121 may be a cube type, but is not limited thereto.

  The light modulation element 122 modulates the light emitted from the illumination unit 110 and emits image light L based on the image control signal. As the light modulation element 122, for example, a light reflection type liquid crystal display element is used, and more specifically, a liquid crystal element such as LCOS (Liquid Crystal On Silicon) is used. The light reflection type liquid crystal display element changes each polarization component (for example, S polarization component or P polarization component) at the time of incidence and at the time of emission. The light modulation element 122 may be a light transmission type liquid crystal display element, and the liquid crystal display element may be a single plate type or a three plate type.

  FIG. 4 is a schematic plan view showing the light modulation element 122. As shown in the figure, the light modulation element 122 has a rectangular plate-shaped incident / exit surface 122a. The incident / exit surface 122a modulates the light beam incident from the illumination unit 110 and emits it as image light L. On the incident / exit surface 122a, the upright direction of the image indicated by the white arrow in the drawing is substantially parallel to the Y-axis direction, and the left-right direction orthogonal to the upright direction of the image is substantially parallel to the X-axis direction.

(Configuration of virtual image optical unit)
FIG. 5 is a plan view of the main part of the virtual image optical unit 130, as viewed from the image display unit 120 side in the Z-axis direction. As shown in FIGS. 1 and 5, the virtual image optical unit 130 includes a collimating optical system 131, an aperture 132, a light guide plate 133, a first hologram grating 134, and a second hologram grating 135, and the light modulation element 122. A virtual image of the image light L from is generated.

  The collimating optical system 131 emits image light L having a predetermined angle of view toward the light guide plate 133. The collimating optical system 131 can include one or a plurality of lenses, but is not limited thereto.

  In the XZ plane shown in FIG. 3, the collimating optical system 131 can cause the first light beam L1 substantially perpendicular to the incident / exit surface 122a of the light modulation element 122 to be incident. The object-side telecentric optical system can be configured. The exit pupil in this case is the wearer's pupil. For example, the collimating optical system 131 emits the first light beam L1 to the light guide plate 133 as a plurality of parallel light beams having different angles of view.

  On the other hand, in the YZ plane shown in FIG. 2, the collimating optical system 131 can make the second light beam L <b> 2 whose emission angle is more distant from the vertical as the distance from the center of the incident / exit surface 122 a of the light modulation element 122 is incident. A telecentric optical system can be configured. For example, the collimating optical system 131 emits the second light beam L2 to the light guide plate 133 as non-parallel light beams having different angles of view.

  The aperture 132 is connected between the collimating optical system 131 and the light guide plate 133. As shown in FIG. 5, the aperture 132 has an opening 132a. The opening 132a is, for example, a rectangle extending along the X-axis direction and the Y-axis direction, and is configured such that the size of the opening 132a differs between the X-axis direction and the Y-axis direction, as will be described later.

  The light guide plate 133 includes a first surface 133a that faces the collimating optical system 131 side of the light guide plate 133 and a second surface 133b that faces the first surface 133a, and is configured in a thin, substantially parallel plate shape. Is done. An incident port 133c and an exit port 133d are formed in the first surface 133a. The incident port 133c allows the image light L to enter from the collimating optical system 131. The exit port 133d emits the image light L toward the pupil.

  Each of the first and second hologram gratings 134 and 135 can be configured as a reflective volume hologram grating.

  The first hologram grating 134 is disposed on the second surface 133b of the light guide plate 133 at a position facing the incident port 133c. The first hologram grating 134 is diffracted and reflected at an angle that satisfies the internal total reflection condition in the light guide plate 133 while maintaining the parallelism of the light beam incident from the incident port 133c.

  The second hologram grating 135 is disposed on the second surface 133b of the light guide plate 133 at a position facing the exit port 133d. The second hologram grating 135 diffracts and reflects the light beam traveling in the light guide plate 133 toward the exit port 133d.

  Next, the progression of the image light L in the light guide plate 133 will be described.

  Referring to FIG. 1, the image light L that has entered the light guide plate 133 from the incident port 133c does not reflect in the Y-axis direction, but travels in the X-axis direction while being repeatedly reflected in the Z-axis direction. Since the light flux included in the image light L has a different number of reflections depending on the angle of view, the optical path length is also different. Since the first light beam L1 is incident on the light guide plate 133 as a parallel light beam as described above, the parallelism is maintained even if the optical path lengths of the light beams are different, so that the image is not disturbed. Thereby, the aperture diameter of the pupil (about 3 mm) and the aperture diameter of the aperture 132 in the X-axis direction can be set to the same size.

  On the other hand, when backward ray tracing is performed from the pupil whose aperture diameter is defined for the second light beam L2, as shown in FIG. 5, depending on the angle of view of each light beam La, Lb, Lc from the pupil (exit port 133d). It progresses so as to spread in the Y-axis direction. That is, the second light beam L2 travels so as to converge from the entrance port 133c toward the exit port 133d in accordance with the angle of view of each light beam La, Lb, Lc. La, Lb, and Lc in FIG. 5 indicate light rays having different angles of view.

  As a result, the aperture 132 is configured such that the opening diameter along the Y-axis direction is larger than the opening diameter along the X-axis direction, and the image light L has a spread in the Y-axis direction rather than the X-axis direction. It is possible to make it incident.

  Next, the optical member 10 will be described in detail.

(Configuration of optical member)
6 and 7 are diagrams showing the configuration of the optical member 10. FIG. 6 is a cross-sectional view, FIGS. 7A and 7B are perspective views as seen from different directions, and FIG. 7C is a view of the incident portion 11 as seen from the Z-axis direction. FIG.

  The optical member 10 is made of a translucent material. The translucent material may contain a thermoplastic resin. Thereby, the optical member 10 can be easily molded by various molding methods. As the thermoplastic resin, for example, a cycloolefin polymer (trade name ZEONEX (registered trademark)), polymethyl methacrylate (PMMA), polycarbonate resin, or the like can be used.

  The refractive index of the optical material can be, for example, 1.48 or more, more preferably 1.52 or more. Thereby, desired optical characteristics can be realized.

  The optical member 10 includes an incident part 11, a curved surface part 12, and an emission part 13. A region including the curved surface portion 12 and the emission portion 13 is referred to as a main body portion 19.

  The incident part 11 has an incident surface 14 and a light source enlarging part 15. The incident surface 14 makes the light emitted from the light source 111 enter. The incident surface 14 may be a flat surface or a curved surface.

  The light source enlarging unit 15 includes, for example, an incident port 15a in which the incident surface 14 is formed, an emission port 15b connected to the main body unit 19, and a light guide unit 15c that connects these. The light source enlargement unit 15 is configured to be able to internally reflect the light beam incident from the incident port 15a on the inner peripheral surface of the light guide unit 15c and to emit the light beam to the emission port 15b. That is, the light source enlarging unit 15 has functions such as a light pipe, a light tunnel, or a rod. The light source enlargement unit 15 may have a film made of a highly reflective metal (for example, silver, aluminum, etc.) on the peripheral surface of the light guide unit 15c.

  The light source enlarging unit 15 can expand the light beam emitted from the light source 111 from the incident surface 14 toward the curved surface portion 12, and the exit port 15b is configured to be larger than the incident port 15a, for example. For example, when the light source enlarging unit 15 is configured to reflect once by the light guide unit 15 c, the light source enlarging unit 15 can emit a light beam capable of forming a plurality of images of the light source 111, and as a result, a secondary light source having a larger size than the light source 111. Can be formed. Furthermore, the uniformity of the secondary light source light can be improved as the number of reflections is increased.

  The light source enlargement unit 15 can spread light rays in all directions. For example, the light source enlarging unit 15 can expand the first light beam L1 along the X-axis direction (first axial direction), and along the Y-axis direction (second axial direction) orthogonal to the X-axis direction. Thus, the second light beam L2 can be expanded (see FIGS. 7A and 8).

  The light source enlargement unit 15 is formed integrally with the main body unit 19, for example. As a result, the positional accuracy of the light source enlargement unit 15 with respect to the main body unit 19 can be improved, and it can be integrally formed in manufacturing.

  The curved surface portion 12 is configured to be able to condense incident light by internally reflecting it toward the emitting portion 13. That is, the curved surface portion 12 can be configured as a concave mirror having a positive refractive power. A secondary light source having a desired size can be formed with a shorter optical path length by the condensing action of the curved surface portion 12, and the optical path length required from the light source 111 to the image display unit 120 can be shortened.

  The curved surface portion 12 has a reflective film 17 on which a reflective surface 16 is formed. Since the curved surface portion 12 includes the reflective film 17, it is not necessary to consider the total reflection condition and the like, and the degree of freedom in design can be increased.

  The reflective film 17 can be formed of, for example, silver or aluminum. Thereby, the reflecting surface 16 having a high reflectance can be formed. Moreover, the reflective film 17 can be a vapor deposition film formed by vapor deposition, for example. Thereby, the adhesiveness of the reflective film 17 can be improved.

  The curved surface part 12 can be configured to include a free curved surface, and in the present embodiment, the reflecting surface 16 can be a free curved surface. The free-form surface is a curved surface shape that cannot be expressed by a plane, a cylindrical surface, or a spherical surface and does not have a rotational symmetry axis. Such a curved surface portion 12 can increase the degree of freedom of the shape and form a secondary light source suitable for the optical design of the image display unit 120 and the virtual image optical unit 130.

  The emission unit 13 has an emission surface 18 and emits the light reflected by the curved surface unit 12 toward the image display unit 120. The emission surface 18 may be configured as a convex lens surface, for example. Thereby, the condensing property of the said reflected light can be improved. More specifically, the emission surface 18 may be a free-form surface.

In the optical member 10 as described above, for example, the curved surface portion 12 has one reflecting surface 16, and the reflecting surface 16 and the emitting surface 18 are connected to each other. The main body 19 includes two or more non-optical surfaces 20 connected to the reflection surface 16 and the emission surface 18 in addition to the reflection surface 16 and the emission surface 18, and a main body entrance surface 21 to which the light source enlargement unit 15 is connected. It has at least 5 sides. With such a configuration, a smaller optical member 10 can be realized.
Next, the detailed shape of the curved surface portion 12 of the optical member 10 will be further described.

(Shape of curved surface)
8A and 8B are diagrams showing the relationship between the curvature and the light flux in the curved surface portion 12, where A is a cross-sectional view seen from the Y-axis direction, and B is a cross-sectional view seen from the X-axis direction. Referring to FIGS. 7A and 8, the curved surface portion 12 reflects the first curvature in the first region S1 where the first light beam L1 expanded by the light source expanding portion 15 reflects and the second light beam L2. You may have the 2nd curvature in 2nd field S2. In the present embodiment, the first curvature may be different from the second curvature. That is, as shown in FIG. 8, the first curvature has a first curvature radius R1, and the second curvature has a second curvature radius R2 different from the first curvature radius R1.

  As described above, the first light beam L1 is light that is spread along the X-axis direction, is reflected by the curved surface portion 12, and is incident on a region along the X-axis direction of the light modulation element 122. As shown in FIG. 4, the X-axis direction corresponds to a direction orthogonal to the upright direction of the image generated by the light modulation element 122. Thereafter, as shown in FIG. 3, the first light beam L1 enters the collimating optical system 131 substantially in parallel, is guided as a parallel light beam through the light guide plate 133, and is emitted from the exit port 133d.

  For this reason, the first light beam L1 can be reflected on the curved surface portion 12 as a light beam including a substantially parallel light beam. That is, the first curvature is configured with a curvature that can reflect the first light beam L1 as telecentric illumination light, for example.

  On the other hand, the second light beam L2 is light that is spread along the Y-axis direction, is reflected by the curved surface portion 12, and is incident on a region along the Y-axis direction of the light modulation element 122. As shown in FIG. 4, the Y-axis direction corresponds to the upright direction of the image generated by the light modulation element 122 in the present embodiment. Thereafter, as shown in FIG. 2, the second light beam L <b> 2 enters the collimating optical system 131 as a non-parallel light beam and enters the light guide plate 133. As described above, the second light beam L2 is guided so as to converge in the light guide plate 133 toward the exit port 133d according to the angle of view (see FIG. 5), and exits from the exit port 133d.

  For this reason, the second light beam L2 can be reflected as a light beam that does not include parallel light rays on the curved surface portion 12. That is, the second curvature is constituted by a curvature that can reflect, for example, the second light beam L2 as non-telecentric illumination light. More specifically, the second curvature is a curvature capable of condensing the second light beam L2 between the optical member 10 and the light modulation element 122, and in the YZ plane viewed from the X-axis direction. It may be configured with a curvature capable of configuring the Koehler illumination system. Thereby, secondary illumination light with more uniform luminance can be formed.

  Moreover, in order to implement | achieve the said optical design, a 1st curvature can be a value smaller than a 2nd curvature. That is, the first radius of curvature R1 can be larger than the second radius of curvature R2.

  Hereinafter, design examples of the optical member 10 will be shown. However, the optical member 10 is not limited to the following configuration.

  FIG. 9 is a cross-sectional view showing an embodiment of the optical member 10. As shown in the figure, the point O is taken as the coordinate origin, and the xyz coordinate system as shown in the figure is set as the reference coordinate system. Here, the x-axis corresponds to the X-axis, the y-axis corresponds to the Z-axis, and the z-axis corresponds to the Y-axis. Further, So1 is the origin of the incident surface 14 in the local coordinate system, So2 is the origin of the reflecting surface 16 in the local coordinate system, and So3 is the origin of the exit surface 18 in the local coordinate system. The unit of the following numerical values is mm. Further, in the same figure, the reflection film is not shown.

The coordinates of So1 in the xyz coordinate system are expressed by the following formulas (1) and (2). Note that θx is a positive direction in which the x-axis is rotated counterclockwise in the positive direction.
(X1, y1) = (6.2, 2.65) (1)
θx = 85.2 (degrees) (2)
The coordinates of So2 in the xyz coordinate system are expressed by the following equations (3) and (4).
(X2, y2) = (− 0.086, 3.41) (3)
θx = + 43.05 (degrees) (4)
The coordinates of So3 in the xyz coordinate system are expressed by the following equations (5) and (6).
(X3, y3) = (− 0.1, 0) (5)
θx = + 9.1 (degrees) (6)

  Further, the length t1 of the short side of the incident surface 14 is 1.30, the length t2 of the light source enlarged portion 15 is 3.00, and the angle α formed by the incident surface 14 and the peripheral surface of the light guide portion 15c is 104.0. Can be degrees.

  On the other hand, the free-form surface shape is generally expressed by the following equation (7), where Z is the sag amount of each local coordinate system from the reference xyz coordinate system.

  In Expression (7), A, B, C, D, E, and F are coefficients of respective terms. These coefficients can be the numerical values shown in Table 1 below, for example.

  With the above configuration, the optical member 10 of the present embodiment can be realized.

As mentioned above, according to this embodiment, since the optical member 10 has the curved surface part 12, a strong condensing effect | action can be exhibited. Therefore, the distance from the light source 111 to the light modulation element 122 can be shortened.
Hereinafter, the effects of the optical member 10 and the illumination unit 110 will be described using reference examples.

  FIG. 10 is a cross-sectional view showing an illumination unit 310 according to a reference example of the present embodiment. As shown in the figure, the illumination unit 310 includes a light source 111, a light pipe 312, a reflection mirror 313, a condenser lens 314, a polarizing plate 112, and a diffusion plate 113. The illumination unit 310 is configured to be able to form a secondary light source by collecting the light reflected by the reflection mirror 313 by the condenser lens 314. Note that the light source 111, the polarizing plate 112, the diffusion plate 113, and the like are the same as those described above, and thus the description thereof is omitted.

  As shown in the figure, when an illumination optical system that generates illumination light to the light modulation element 122 without using the optical member 10 is to be configured, more parts are required. As a result, the optical path length becomes long and it is difficult to reduce the size of the configuration. In addition, it is difficult to accurately arrange the parts, and it is difficult to maintain long-term reliability. In addition, the condensing lens 315 has to be configured with a convex surface that can secure sufficient light condensing performance, which also hinders downsizing of the configuration.

  Therefore, according to the optical member 10 shown with the broken line of the figure, compared with the structure of the said illumination unit 310, size reduction of the illumination unit 110 is realizable. Furthermore, since the optical member 10 includes the light source enlargement unit 15 having a light pipe function, the configuration of the above-described light pipe 312 is not necessary, and can contribute to further downsizing. Further, since the light source enlargement unit 15 is integrated with the main body unit 19, the optical positional accuracy can be further increased.

  Further, according to the optical member 10, since the reflecting surface 16 of the curved surface portion 12 and the emitting surface 18 of the emitting portion 13 are connected, the light beam reflected by the curved surface portion 12 can be emitted from the immediate emitting portion 13. It is possible to achieve further downsizing.

  Furthermore, according to the wearable display 100 having the optical member 10 (illumination unit 110) according to the present embodiment, the entire apparatus can be reduced in size and weight. In addition, the reduction in the number of parts can increase the optical positional accuracy, facilitate assembly during production, and increase productivity.

  In addition, since the curved surface portion 12 includes a free curved surface, an optimal illumination optical system can be provided for the wearable display 100 having the virtual image optical unit 130.

  Furthermore, the present technology is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the present disclosure.

  For example, the emission surface 18 of the emission unit 13 may be configured as a Fresnel lens surface as shown in FIG. Thereby, the output surface 18 can be made thin and have a desired lens function.

  Further, the emission surface 18 may be configured as a surface having a diffusion function. More specifically, the exit surface 18 may be screen-printed or may be configured in a fine lens array. In this case, the emission surface 18 may be a flat surface or a curved surface.

  In the above embodiment, the curved surface portion 12 has a metal reflective film, but the present invention is not limited to this. For example, the curved surface portion may have a wire grid on which a reflective surface is formed. Thereby, only a specific polarization component can be reflected on the reflecting surface. Therefore, a polarizing plate is unnecessary and it can contribute to further miniaturization.

  Moreover, although the light source expansion part 15 demonstrated that the above-mentioned embodiment was integrated with the main-body part 19, it is not limited to this. For example, the light source enlargement part 15 may be joined to the main body part 19 through an adhesive made of a translucent material. Further, the light source enlargement unit 15 is not limited to the light pipe configuration, and may be a structure such as a microlens array.

  In the above embodiment, although it demonstrated that the illumination unit 110 had the polarizing plate 112 and the diffusion plate 113, you may have only any one, and it is good also as a structure which does not have any.

  The image display unit 120 is not limited to the configuration including the polarization beam splitter 121, and can be appropriately configured according to the configuration of the light modulation element 122. The light modulation element 122 is not limited to the liquid crystal display element, and for example, a digital micromirror device (DMD) may be used. Further, the virtual image optical unit 130 is not limited to the above configuration.

  Moreover, the optical element and the illumination unit according to the above embodiment are not limited to examples applied to a wearable display. For example, the optical element and the illumination unit can be mounted on various image display devices that perform image display using a light modulation element, such as a projector device, a PC (Personal Computer), a tablet PC, a smartphone, and a tablet terminal.

In addition, this technique can also take the following structures.
(1) An illumination unit capable of supplying light to a light modulation element,
A light source;
A translucent material having an incident part into which light is incident from the light source, an emitting part, and a curved surface part capable of internally reflecting and condensing the incident light toward the emitting part An illumination unit comprising: an optical member configured between the light source and the light modulation element.
(2) The lighting unit according to (1) above,
The curved surface portion has a reflection film on which a reflection surface is formed.
(3) The illumination unit according to (1) or (2) above,
The curved surface portion includes a free curved surface.
(4) The lighting unit according to any one of (1) to (3) above,
The incident part is
An incident surface;
An illumination unit comprising: a light source expansion unit capable of expanding a light beam emitted from the light source from the incident surface toward the curved surface portion.
(5) The illumination unit according to (4) above,
The optical member further includes a main body portion including the curved surface portion and the emitting portion,
The light source enlargement unit is an illumination unit formed integrally with the main body unit.
(6) The illumination unit according to (4) or (5) above,
The curved surface portion extends along a first curvature in a first region in which a first light beam spread along the first axial direction is reflected, and a second axial direction orthogonal to the first axial direction. And a second curvature in a second region where the second light beam spread out is reflected.
(7) The illumination unit according to (6) above,
The first axial direction corresponds to a direction orthogonal to the erect direction of the image generated by the light modulation element,
The second axial direction corresponds to the upright direction of the image.
(8) The illumination unit according to (7) above,
The first curvature is smaller than the second curvature.
(9) The illumination unit according to (7) or (8) above,
The first curvature is a curvature capable of reflecting the first light flux as telecentric illumination light,
The second curvature is a curvature capable of reflecting the second light flux as non-telecentric illumination light.
(10) The illumination unit according to any one of (1) to (9) above,
The translucent material is a lighting unit including a thermoplastic resin.
(11) An optical member capable of supplying light emitted from a light source to a light modulation element,
An incident surface on which a light beam emitted from the light source is incident; a light source enlargement unit capable of expanding the light beam; an incident unit on which light is incident from the light source;
An emission part;
An optical member made of a translucent material, comprising: a curved surface portion capable of internally reflecting and condensing the incident light toward the emitting portion.
(12) a light source;
A translucent material having an incident part into which light is incident from the light source, an emitting part, and a curved surface part capable of internally reflecting and condensing the incident light toward the emitting part An illumination unit comprising: an optical member configured between the light source and the light modulation element;
A light modulation element that modulates light emitted from the illumination unit;
A wearable display comprising: a virtual image optical unit that generates a virtual image of image light from the light modulation element.
(13) a light source;
A translucent material having an incident part into which light is incident from the light source, an emitting part, and a curved surface part capable of internally reflecting and condensing the incident light toward the emitting part An illumination unit comprising: an optical member configured between the light source and the light modulation element;
A light modulation element that modulates light emitted from the illumination unit;
An image display device comprising: a virtual image optical unit that generates a virtual image of image light from the light modulation element.

DESCRIPTION OF SYMBOLS 10 ... Optical member 11 ... Incident part 12 ... Curved part 13 ... Outgoing part 14 ... Incident surface 15 ... Light diffusing part 16 ... Reflecting surface 17 ... Reflecting film 18 ... Outgoing surface 100 ... Wearable display 110 ... Illumination unit 111 ... Light source 122 ... Light modulator 130 ... Virtual image optical unit

Claims (13)

An illumination unit capable of supplying light to a light modulation element,
A light source;
A translucent material having an incident part into which light is incident from the light source, an emitting part, and a curved surface part capable of internally reflecting and condensing the incident light toward the emitting part An illumination unit comprising: an optical member configured between the light source and the light modulation element. The lighting unit according to claim 1,
The curved surface portion has a reflection film on which a reflection surface is formed. The lighting unit according to claim 1,
The curved surface portion includes a free curved surface. The lighting unit according to claim 1,
The incident portion is
An incident surface;
An illumination unit, comprising: a light source expansion unit capable of expanding a light beam emitted from the light source from the incident surface toward the curved surface portion. The lighting unit according to claim 4,
The optical member further includes a main body portion including the curved surface portion and the emitting portion,
The light source enlarging part is formed integrally with the main body part. The lighting unit according to claim 4,
The curved surface portion extends along a first curvature in a first region in which a first light beam spread along the first axial direction is reflected, and a second axial direction orthogonal to the first axial direction. And a second curvature in a second region where the second light beam spread out is reflected. The lighting unit according to claim 6,
The first axial direction corresponds to a direction orthogonal to an erect direction of an image generated by the light modulation element;
The second axial direction corresponds to the upright direction of the image. The lighting unit according to claim 7,
The first curvature is smaller than the second curvature. The lighting unit according to claim 7,
The first curvature is a curvature capable of reflecting the first light flux as telecentric illumination light,
The second curvature is a curvature capable of reflecting the second light flux as non-telecentric illumination light. The lighting unit according to claim 1,
The translucent material includes a thermoplastic resin. An optical member capable of supplying light emitted from a light source to a light modulation element,
An incident surface on which a light beam emitted from the light source is incident; a light source enlargement unit capable of expanding the light beam; an incident unit on which light is incident from the light source;
An emission part;
An optical member made of a translucent material, comprising: a curved surface portion capable of internally reflecting the incident light toward the emitting portion and collecting the incident light. A light source;
A translucent material having an incident part into which light is incident from the light source, an emitting part, and a curved surface part capable of internally reflecting and condensing the incident light toward the emitting part An illumination unit comprising: an optical member configured between the light source and the light modulation element;
A light modulation element that modulates light emitted from the illumination unit;
A wearable display comprising: a virtual image optical unit that generates a virtual image of image light from the light modulation element. A light source;
A translucent material having an incident part into which light is incident from the light source, an emitting part, and a curved surface part capable of internally reflecting and condensing the incident light toward the emitting part An illumination unit comprising: an optical member configured between the light source and the light modulation element;
An image display device comprising: a light modulation element that modulates light emitted from the illumination unit.

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