JP2015145973A - Virtual image display device and optical element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an easy-to-manufacture virtual image display device which has a simple configuration, and an optical element.SOLUTION: A virtual image display device 1 includes an image forming section which emits light L, and an expansion optical section 5 which receives the light L emitted from the image forming section and expands the light L in a two-dimensional manner. The expansion optical section 5 includes: an incident section where the light L is made incident; a first light guide plate 51 having a first principal surface 511 arranged obliquely with respect to an incident direction in which the light L is made incident on the incident section, and a partially transmissive reflection surface 200 arranged in parallel with the first principal surface 511, to reflect a part of the light L and transmit the part of the light L; a second light guide plate 52 which guides the light L which has transmitted through the partially transmissive reflection surface 200; and a light extraction section which extracts the light L to the outside of the light guide plate 52. The first light guide plate 51 multiple-reflects the light L between the first principal surface 511 and the partially transmissive reflection surface 200, and makes the light L transmitting through the partially transmissive reflection surface 200 incident on the second light guide plate 52.

Description

For example, a virtual image display device that displays an image visually recognized by an observer as a virtual image, such as a head-mounted display, is known (see, for example, Patent Document 1).
The virtual image display device described in Patent Literature 1 includes a light source that emits light, and a light expansion element (optical element) that expands the light emitted from the light source two-dimensionally. This light expanding element has a first half mirror group and a second half mirror group.

The first half mirror group includes a plurality of first half mirrors that reflect a part of the light incident from the light source to the second half mirror group side and transmit a part of the incident light. In the first half mirror group, the first half mirrors are inclined with respect to the direction in which light is incident from the light source, and are arranged in parallel to each other along the direction in which light is incident from the light source.
The second half mirror group reflects a part of the light reflected by the first half mirror group toward the observer (light extraction unit), and a part of the light reflected by the first half mirror group. A plurality of second half mirrors to be transmitted are provided. In the second half mirror group, each second half mirror is inclined with respect to the direction in which light enters from the first half mirror group, and along the direction in which light enters from the first half mirror group. Are lined up in parallel with each other.

A part of the light incident from the light source is reflected by the first half mirror toward the second half mirror group, and a part of the light is transmitted. The transmitted light is partially reflected and partially transmitted as described above. This reflection and transmission are repeated by the first half mirrors, so that the light is expanded in the direction in which the first half mirrors are arranged. The light expanded in the first direction by the first half mirror group is expanded in the direction in which the second half mirrors are arranged by the second half mirror group on the same principle.
Thus, the light emitted from the light source is magnified in two different directions by the light magnifying element and visually recognized as a relatively large virtual image by the observer.

  However, in this light expansion element, it is necessary to make the parallelism of each first half mirror very high and make the parallelism of each second half mirror very high. To achieve this, very high precision technology is required. Moreover, in this light expansion element, the number of first half mirrors and second half mirrors increases as light is expanded. As a result, the configuration of the light expanding element becomes very complicated. Thus, it is very difficult to manufacture a high-performance light magnifying element.

Special table 2004-526202 gazette

  An object of the present invention is to provide a virtual image display device and an optical element that have a simple configuration and are easy to manufacture.

Such an object is achieved by the present invention described below.
The virtual image display device of the present invention generates an image light modulated based on a video signal, and emits the image light; and
The image light emitted from the image forming unit is incident, and an expansion optical unit that expands the image light in two dimensions, and
The magnifying optical part includes a light incident part on which the image light is incident,
A first reflecting surface provided to be inclined with respect to an incident direction in which the image light is incident on the light incident portion; and provided in parallel with the first reflecting surface to reflect a part of the image light; A first light guide having a second reflecting surface that transmits part of the image light;
A second light guide part for guiding the image light transmitted through the second reflecting surface;
A light extraction unit that is provided in the second light guide unit and extracts the image light guided through the second light guide unit to the outside of the second light guide unit;
The first light guide unit multi-reflects the image light between the first reflection surface and the second reflection surface, and transmits the image light transmitted through the second reflection surface to the second light guide unit. It is made to inject into.

According to the virtual image display device configured as described above, the image light is multiple-reflected by the first light guide unit, is expanded in a predetermined direction, and is guided through the second light guide unit. The image light extracted by the light extraction unit of the second light guide unit is enlarged to the size of the light extraction unit.
Further, it is possible to obtain a virtual image display device that expands image light two-dimensionally with a simple configuration in which the first reflection surface and the second reflection surface are provided in parallel.

In the virtual image display device of the present invention, it is preferable that the transmittance of the second reflecting surface has a portion that increases as the distance from the light incident portion increases.
When the transmittance of the second reflecting surface is constant, the intensity (light quantity) of the image light emitted from the second reflecting surface decreases as the distance from the light incident portion increases. However, since the transmittance of the second reflecting surface increases with distance from the light incident portion, the intensity (light quantity) of the image light emitted from the second reflecting surface can be made substantially uniform. Therefore, it is possible to reduce the light amount unevenness of the virtual image displayed on the light extraction unit.
In the virtual image display device of the present invention, it is preferable that an inclination angle of the first reflecting surface and the second reflecting surface is 20 to 70 ° with respect to the incident direction.
Thereby, the image light guided through the second light guide unit can be made as parallel as possible to the longitudinal direction of the second light guide unit.

In the virtual image display device of the present invention, the second light guide section includes a third reflection surface and a fourth reflection surface provided to face each other, and the video light is transmitted to the third reflection surface and the fourth reflection surface. It is preferable to make multiple reflections between the two.
Thereby, the light emitted from the first light guide is repeatedly reflected between the third reflection surface and the fourth reflection surface, and is reliably guided through the second light guide.

In the virtual image display device of the present invention, the second light guide unit includes a plate material,
One main surface of the pair of main surfaces of the plate member preferably functions as the third reflecting surface, and the other main surface functions as the fourth reflecting surface.
Thereby, the image light emitted from the first light guide unit is guided through the plate material. Therefore, the configuration of the second light guide unit can be simplified.
In the virtual image display device of the present invention, it is preferable that the light extraction unit includes a hologram provided on one of the third reflection surface and the fourth reflection surface.
Thereby, the advancing direction of image light can be changed easily, and the virtual image display apparatus excellent in light utilization efficiency can be obtained.

In the virtual image display device of the present invention, the second light guide unit includes a first plate member and a second plate member provided to face each other,
It is preferable that a main surface of the first plate member on the second plate member side functions as the third reflecting surface, and a main surface of the second plate member on the first plate member side functions as the fourth reflecting surface.
Thereby, between a 1st board | plate material and a 2nd board | plate material functions as a 2nd light guide part.
In the virtual image display device of the present invention, it is preferable that one of the first plate member and the second plate member is made of a light transmissive material.
Thereby, the board | plate material comprised with the light transmissive material can function as a light extraction part.

In the virtual image display device of the present invention, the image light emitted from the image forming unit is incident, and includes a mirror unit that reflects the image light,
It is preferable that the image light is incident on the first light guide unit after being reflected by the mirror unit.
Thereby, video light can be reliably incident on the first light guide.

In the virtual image display device of the present invention, it is preferable that the image forming unit includes a light source that emits light and an optical scanner that scans the light emitted from the light source.
As a result, it is possible to form an image visually recognized by the observer and to reduce the size of the image forming unit.
In the virtual image display device of the present invention, it is preferable that the image forming unit includes a light source and a spatial light modulation device that modulates light emitted from the light source based on the video signal.
Thereby, the image | video which an observer visually recognizes can be formed.
In the virtual image display device of the present invention, it is preferable that the image forming unit includes an organic EL panel.
As a result, it is possible to form an image visually recognized by the observer and to reduce the size of the image forming unit.

The optical element of the present invention includes a light incident portion on which image light is incident,
A first reflecting surface provided to be inclined with respect to an incident direction in which the image light is incident on the light incident portion; and provided in parallel with the first reflecting surface to reflect a part of the image light; A first light guide having a second reflecting surface that transmits part of the image light;
A second light guide part for guiding the image light transmitted through the second reflecting surface;
A light extraction unit that is provided in the second light guide unit and extracts the image light guided through the second light guide unit to the outside of the second light guide unit;
The first light guide unit multi-reflects the image light between the first reflection surface and the second reflection surface, and transmits the image light transmitted through the second reflection surface to the second light guide unit. It is made to inject into.

According to the optical element configured as described above, the image light is multiple-reflected by the first light guide unit, is expanded in a predetermined direction, and is guided through the second light guide unit. The image light extracted by the light extraction unit of the second light guide unit is enlarged to the size of the light extraction unit.
In addition, an optical element that expands image light two-dimensionally can be obtained with a simple configuration in which the first reflecting surface and the second reflecting surface are provided in parallel.

1 is a perspective view showing a first embodiment of a virtual image display device (optical element) of the present invention. It is a schematic block diagram of the virtual image display apparatus shown in FIG. It is a block diagram of the virtual image display apparatus shown in FIG. (A) And (b) is a figure which shows an example of the drive signal of the drive signal production | generation part with which the virtual image display apparatus shown in FIG. 1 is provided. It is a top view of the optical scanner with which the virtual image display apparatus shown in FIG. 1 is provided. It is sectional drawing of the optical scanner in FIG. It is a figure which shows the optical element shown in FIG. 1, (a) is a top view, (b) is a side view. (A) And (b) is an enlarged detail drawing which shows the path | route of the light which injected into the optical element shown in FIG. It is a top view which shows 2nd Embodiment of the virtual image display apparatus (optical element) of this invention. It is a top view which shows 3rd Embodiment of the virtual image display apparatus (optical element) of this invention. It is a top view which shows 4th Embodiment of the virtual image display apparatus (optical element) of this invention. It is a top view which shows 5th Embodiment of the virtual image display apparatus (optical element) of this invention. It is a figure which shows 6th Embodiment of the virtual image display apparatus (optical element) of this invention, (a) is a top view, (b) is the figure seen from the arrow A direction in (a). It is a figure which shows the image formation part with which 7th Embodiment of the virtual image display apparatus (optical element) of this invention is provided. It is a figure which shows the image formation part with which 8th Embodiment of the virtual image display apparatus (optical element) of this invention is provided. It is a figure which shows the image formation part with which 9th Embodiment of the virtual image display apparatus (optical element) of this invention is provided. It is a figure which shows the image formation part with which 10th Embodiment of the virtual image display apparatus (optical element) of this invention is provided.

Hereinafter, a preferred embodiment of a virtual image display device of the present invention will be described with reference to the accompanying drawings.
<First Embodiment>
1 is a perspective view showing a first embodiment of a virtual image display device (optical element) of the present invention, FIG. 2 is a schematic configuration diagram of the virtual image display device shown in FIG. 1, and FIG. 3 is a virtual image display shown in FIG. It is a block diagram of an apparatus. 4 is a diagram illustrating an example of a drive signal of a drive signal generation unit included in the virtual image display device illustrated in FIG. 1, and FIG. 5 is a plan view of an optical scanner included in the virtual image display device illustrated in FIG. 1. 6 is a cross-sectional view of the optical scanner in FIG. 5, FIG. 7 is a view showing the optical element shown in FIG. 1, (a) is a plan view, (b) is a side view, and FIG. (A) And (b) is an enlarged detail drawing which shows the path | route of the light which injected into the optical element shown in FIG. 2, FIG. 7, and FIG. 8 show only the principal ray of light (light in the direction that coincides with the optical axis).

As shown in FIG. 1, the virtual image display device 1 of the present embodiment is a head-mounted display (head-mounted virtual image display device) having an appearance like glasses, and is used by being worn on the observer's head. Then, the observer visually recognizes an image of a virtual image in a state of being superimposed on an external image.
The virtual image display device 1 includes a frame 2, a signal generation unit 3, a scanning light emitting unit 4, and a magnifying optical unit 5.

In such a virtual image display device 1, the signal generation unit 3 generates signal light modulated based on image information, and the scanning light emitting unit 4 scans the signal light two-dimensionally to scan light (hereinafter referred to as “light”). The “scanning light” is also referred to as “video light” or “light”), and the magnifying optical unit 5 enlarges the scanning light two-dimensionally to allow the observer to visually recognize it as a virtual image. In the present embodiment, the signal generating unit 3 and the scanning light emitting unit 4 constitute an image forming unit 10.
The virtual image display device 1 forms a virtual image for the right eye and a virtual image for the left eye, but for convenience of explanation, in each drawing, the configuration for forming the virtual image for the left eye is representatively shown. The configuration for forming the virtual image for the right eye shown in the drawing is the same as the configuration for forming the virtual image for the left eye, and is not shown.

(flame)
As shown in FIG. 1, the frame 2 has a shape like a spectacle frame, and has a function of supporting the signal generating unit 3, the scanning light emitting unit 4, and the magnifying optical unit 5.
Further, when the frame 2 is mounted on the observer's head, the frame 2 comes into contact with the observer's nose, and is connected to the lens unit 21 disposed in front of the observer's eyes and both ends of the lens unit 21, respectively. It has a pair of temple parts (vine parts) 22 that come into contact with the ears of the observer when mounted on the observer's head. The lens unit 21 includes the magnifying optical unit 5, and the temple unit 22 includes the signal generating unit 3 and the scanning light emitting unit 4.
The shape of the frame 2 is not limited to that shown in the drawing as long as it can be attached to the observer's head.

(Signal generator)
As shown in FIGS. 1 and 2, the signal generation unit 3 is built in one temple unit 22 of the frame 2 described above.
As shown in FIGS. 2 and 3, the signal generation unit 3 includes a signal light generation unit 31, a drive signal generation unit 32, a control unit 33, and a lens 34.

The signal light generation unit 31 generates signal light that is scanned (optically scanned) by an optical scanning unit 42 (optical scanner) of the scanning light emitting unit 4 described later.
The signal light generation unit 31 includes a plurality of light sources 311R, 311G, and 311B having different wavelengths, a plurality of drive circuits 312R, 312G, and 312B, and a light combining unit (combining unit) 313.

The light source 311R (R light source) emits red light, the light source 311G (G light source) emits green light, and the light source 311B (B light source) emits blue light. . By using such three colors of light, a full color image can be displayed.
Such light sources 311R, 311G, and 311B are not particularly limited. For example, laser diodes and LEDs can be used.
Such light sources 311R, 311G, and 311B are electrically connected to the drive circuits 312R, 312G, and 312B, respectively.

The drive circuit 312R has a function of driving the above-described light source 311R, the drive circuit 312G has a function of driving the above-described light source 311G, and the drive circuit 312B has a function of driving the above-described light source 311B.
The three (three colors) light emitted from the light sources 311R, 311G, and 311B driven by the driving circuits 312R, 312G, and 312B is incident on the light combining unit 313.

The light combining unit 313 combines light from a plurality of light sources 311R, 311G, and 311B. Thereby, in the present embodiment, the signal light can be transmitted from the signal generation unit 3 to the scanning light emitting unit 4 through the single optical fiber 7 provided along the temple unit 22 of the frame 2.
In the present embodiment, the light combining unit 313 includes two dichroic mirrors 313a and 313b.

The dichroic mirror 313a has a function of transmitting red light and reflecting green light. The dichroic mirror 313b has a function of transmitting red light and green light and reflecting blue light.
By using such dichroic mirrors 313a and 313b, signal light is formed by synthesizing light of three colors of red light, green light and blue light from the light sources 311R, 311G and 311B.

In the present embodiment, the light sources 311R, 311G, and 311B are arranged so that the optical path lengths of red light, green light, and blue light from the light sources 311R, 311G, and 311B are equal to each other.
The light combining unit 313 is not limited to the configuration using the dichroic mirror as described above, and may be configured by, for example, an optical waveguide, an optical fiber, or the like.

The signal light generated by the signal light generation unit 31 is collected by the lens 34 and then input to the optical fiber 7. Then, the signal light is transmitted to the optical scanning unit 42 of the scanning light emitting unit 4 described later via the optical fiber 7.
Since the signal light is guided to the optical scanning unit 42 by the optical fiber 7 in this way, the degree of freedom of the installation position of the signal light generation unit 31 is increased.
The lens 34 may be provided as necessary and can be omitted. Further, for example, the signal light can be input to the optical fiber 7 by providing a lens between the light sources 311R, 311G, 311B and the light combining unit 313 instead of the lens 34.

The drive signal generating unit 32 generates a drive signal for driving an optical scanning unit (optical scanner) 42 of the scanning light emitting unit 4 described later.
The drive signal generation unit 32 includes a drive circuit 321 (first drive circuit) that generates a first drive signal used for scanning in the first direction (horizontal scan) of the optical scanning unit 42, and the optical scanning unit 42. A drive circuit 322 (second drive circuit) that generates a second drive signal used for scanning (vertical scanning) in a second direction orthogonal to the first direction.
Such a drive signal generation unit 32 is electrically connected to an optical scanning unit 42 of the scanning light emitting unit 4 described later via a signal line (not shown). Thus, the drive signals (first drive signal and second drive signal) generated by the drive signal generation unit 32 are input to the optical scanning unit 42 of the scanning light emitting unit 4 described later.

The drive circuits 312R, 312G, and 312B of the signal light generation unit 31 and the drive circuits 321 and 322 of the drive signal generation unit 32 as described above are electrically connected to the control unit 33.
The control unit 33 has a function of controlling driving of the drive circuits 312R, 312G, and 312B of the signal light generation unit 31 and the drive circuits 321 and 322 of the drive signal generation unit 32 based on the video signal (image signal).
As a result, the signal light generation unit 31 generates signal light modulated according to the image information, and the drive signal generation unit 32 generates a drive signal according to the image information.

(Scanning light emitting part)
The scanning light emitting unit 4 is built in the temple unit 22. As shown in FIG. 2, the scanning light emitting unit 4 includes a light scanning unit 42 and a lens (coupling lens) 43.
The optical scanning unit 42 is an optical scanner that two-dimensionally scans the signal light from the signal light generation unit 31. Scanning light is formed by scanning the signal light with the optical scanning unit 42.

As shown in FIG. 5, the optical scanning unit 42 includes a movable mirror unit 11, a pair of shaft portions 12a and 12b (first shaft portions), a frame body portion 13, and two pairs of shaft portions 14a. 14 b, 14 c, 14 d (second shaft portion), a support portion 15, a permanent magnet 16, and a coil 17. In other words, the optical scanning unit 42 has a so-called gimbal structure.
Here, the movable mirror portion 11 and the pair of shaft portions 12a and 12b constitute a first vibration system that swings (reciprocates) around the Y1 axis (first axis). In addition, the movable mirror part 11, the pair of shaft parts 12a and 12b, the frame part 13, the two pairs of shaft parts 14a, 14b, 14c and 14d, and the permanent magnet 16 are swung around the X1 axis (second axis). A second vibration system that moves (reciprocates) is configured.
The optical scanning unit 42 includes the signal superimposing unit 18 (see FIG. 6), and the permanent magnet 16, the coil 17, the signal superimposing unit 18, and the drive signal generating unit 32 include the first vibration system and the above-described first vibration system. A drive unit that drives the second vibration system (that is, the movable mirror unit 11 swings around the X1 axis and the Y1 axis) is configured.

Hereinafter, each part of the optical scanning unit 42 will be sequentially described in detail.
The movable mirror part 11 includes a base part 111 (movable part) and a light reflection plate 113 fixed to the base part 111 via a spacer 112.
A light reflecting portion 114 having light reflectivity is provided on the upper surface (one surface) of the light reflecting plate 113.
The light reflecting plate 113 is provided so as to be separated from the shaft portions 12a and 12b in the thickness direction and overlap the shaft portions 12a and 12b when viewed from the thickness direction (hereinafter also referred to as “plan view”). ing.

  Therefore, the area of the plate surface of the light reflecting plate 113 can be increased while shortening the distance between the shaft portion 12a and the shaft portion 12b. Further, since the distance between the shaft portion 12a and the shaft portion 12b can be shortened, the size of the frame body portion 13 can be reduced. Furthermore, since the size of the frame body portion 13 can be reduced, the distance between the shaft portions 14a and 14b and the shaft portions 14c and 14d can be shortened.

For this reason, even if the area of the light reflecting plate 113 is increased, the light scanning unit 42 can be downsized. In other words, the size of the optical scanning unit 42 with respect to the area of the light reflecting unit 114 can be reduced.
Further, the light reflection plate 113 is formed so as to cover the entire shaft portions 12a and 12b in plan view. In other words, each of the shaft portions 12a and 12b is located inside the outer periphery of the light reflecting plate 113 in plan view. Thereby, the area of the plate | board surface of the light reflection board 113 becomes large, As a result, the area of the light reflection part 114 can be enlarged. Further, it is possible to prevent unnecessary light from being reflected by the shaft portions 12a and 12b and becoming stray light.

  The light reflecting plate 113 is formed so as to cover the entire frame body portion 13 in plan view. In other words, the frame body portion 13 is located on the inner side with respect to the outer periphery of the light reflecting plate 113 in plan view. Thereby, the area of the plate | board surface of the light reflection board 113 becomes large, As a result, the area of the light reflection part 114 can be enlarged. Further, it is possible to prevent unnecessary light from being reflected by the frame body portion 13 and becoming stray light.

Furthermore, the light reflecting plate 113 is formed so as to cover the entire shaft portions 14a, 14b, 14c, and 14d in plan view. In other words, each of the shaft portions 14a, 14b, 14c, and 14d is located inside the outer periphery of the light reflecting plate 113 in plan view. Thereby, the area of the plate | board surface of the light reflection board 113 becomes large, As a result, the area of the light reflection part 114 can be enlarged. Further, it is possible to prevent unnecessary light from being reflected by the shaft portions 14a, 14b, 14c, and 14d and becoming stray light.
In the present embodiment, the light reflecting plate 113 has a circular shape in plan view. In addition, the planar view shape of the light reflection plate 113 is not limited to this, and may be a polygon such as an ellipse or a rectangle.

A hard layer 115 is provided on the lower surface (the other surface) of the light reflecting plate 113 as shown in FIG.
The hard layer 115 is made of a material harder than the constituent material of the light reflecting plate 113 main body. Thereby, the rigidity of the light reflecting plate 113 can be increased. Therefore, it is possible to prevent or suppress the bending when the light reflecting plate 113 swings. Further, the thickness of the light reflecting plate 113 can be reduced, and the moment of inertia when the light reflecting plate 113 swings around the X1 axis and the Y1 axis can be suppressed.

The constituent material of the hard layer 115 is not particularly limited as long as it is a material harder than the constituent material of the light reflecting plate 113 main body. For example, diamond, carbon nitride film, crystal, sapphire, lithium tantalate Although potassium niobate can be used, it is particularly preferable to use diamond.
The thickness (average) of the hard layer 115 is not particularly limited, but is preferably about 1 to 10 μm, and more preferably about 1 to 5 μm.
Moreover, the hard layer 115 may be comprised by the single layer, and may be comprised by the laminated body of several layers. The hard layer 115 is provided as necessary, and can be omitted.
The hard layer 115 can be formed by, for example, chemical vapor deposition (CVD) such as plasma CVD, thermal CVD, or laser CVD, dry plating such as vacuum deposition, sputtering, or ion plating, electrolytic plating, or immersion plating. Further, wet plating methods such as electroless plating, thermal spraying, and joining of sheet-like members can be used.

In addition, the lower surface of the light reflecting plate 113 is fixed to the base 111 via a spacer 112. Thereby, the light reflecting plate 113 can be swung around the Y1 axis while preventing contact with the shaft portions 12a, 12b, the frame body portion 13 and the shaft portions 14a, 14b, 14c, 14d.
In addition, each of the base portions 111 is located on the inner side with respect to the outer periphery of the light reflecting plate 113 in plan view. That is, the area of the surface (plate surface) where the light reflecting portion 114 of the light reflecting plate 113 is provided is larger than the area of the surface where the spacer 112 of the base 111 is fixed. The area of the base 111 in plan view is preferably as small as possible if the base 111 can support the light reflecting plate 113 via the spacer 112. Thereby, the distance between the shaft part 12a and the shaft part 12b can be reduced while increasing the area of the plate surface of the light reflecting plate 113.

As shown in FIG. 5, the frame body portion 13 has a frame shape and is provided so as to surround the base portion 111 of the movable mirror portion 11 described above. In other words, the base 111 of the movable mirror portion 11 is provided inside the frame body portion 13 having a frame shape.
And the frame part 13 is supported by the support part 15 via axial part 14a, 14b, 14c, 14d. Further, the base 111 of the movable mirror part 11 is supported by the frame body part 13 via the shaft parts 12a and 12b.

  Further, the frame body portion 13 has a length in the direction along the Y1 axis that is longer than a length in the direction along the X1 axis. That is, when the length of the frame body portion 13 in the direction along the Y1 axis is a and the length of the frame body portion 13 in the direction along the X1 axis is b, the relationship a> b is satisfied. Thereby, the length of the optical scanning unit 42 in the direction along the X1 axis can be suppressed while ensuring the length necessary for the shaft portions 12a and 12b.

Moreover, the frame part 13 has comprised the shape along the external shape of the structure which consists of the base 111 of the movable mirror part 11, and one pair of axial parts 12a and 12b by planar view. Accordingly, the frame body portion 13 is allowed while allowing the vibration of the first vibration system constituted by the movable mirror portion 11 and the pair of shaft portions 12a and 12b, that is, swinging of the movable mirror portion 11 around the Y1 axis. Can be miniaturized.
The shape of the frame body portion 13 is not limited to the illustrated shape as long as it is a frame shape surrounding the base 111 of the movable mirror portion 11.

The shaft portions 12a, 12b and the shaft portions 14a, 14b, 14c, 14d can be elastically deformed, respectively.
The shaft portions 12a and 12b connect the movable mirror portion 11 and the frame body portion 13 so that the movable mirror portion 11 can be rotated (oscillated) around the Y1 axis (first axis). . Further, the shaft portions 14a, 14b, 14c, and 14d are arranged so that the frame body portion 13 can rotate (swing) around the X1 axis (second axis) orthogonal to the Y1 axis. The support part 15 is connected.

The shaft portions 12 a and 12 b are disposed so as to face each other via the base 111 of the movable mirror portion 11. Each of the shaft portions 12a and 12b has a longitudinal shape extending in the direction along the Y1 axis. Each of the shaft portions 12 a and 12 b has one end connected to the base 111 and the other end connected to the frame body 13. In addition, the shaft portions 12a and 12b are arranged so that the central axis coincides with the Y1 axis.
Each of the shaft portions 12a and 12b is twisted and deformed as the movable mirror portion 11 swings around the Y1 axis.

The shaft portions 14a and 14b and the shaft portions 14c and 14d are arranged so as to face each other with the frame body portion 13 interposed therebetween. The shaft portions 14a, 14b, 14c, and 14d each have a longitudinal shape that extends in a direction along the X1 axis. Each of the shaft portions 14 a, 14 b, 14 c, and 14 d has one end connected to the frame body portion 13 and the other end connected to the support portion 15. The shaft portions 14a and 14b are disposed so as to face each other via the X1 axis. Similarly, the shaft portions 14c and 14d are disposed so as to face each other via the X1 axis.
In such shaft portions 14a, 14b, 14c, and 14d, the shaft portions 14a and 14b and the shaft portions 14c and 14d as a whole are twisted and deformed as the frame body portion 13 swings around the X1 axis.
As described above, the movable mirror portion 11 can be swung around the Y1 axis, and the frame body portion 13 can be swung around the X1 axis, so that the movable mirror portion 11 is orthogonal to the X1 axis and the Y1 axis. Can be swung (reciprocating) around the two axes.

In addition, at least one of the shaft portions 12a and 12b and at least one shaft portion of the shaft portions 14a, 14b, 14c, and 14d have an angle such as a strain sensor, for example. A detection sensor is provided. This angle detection sensor can detect angle information of the light scanning unit 42, more specifically, the swing angles of the light reflecting unit 114 around the X1 axis and around the Y1 axis. This detection result is input to the control unit 33 via a cable (not shown).
The shapes of the shaft portions 12a and 12b and the shaft portions 14a, 14b, 14c, and 14d are not limited to those described above. For example, the shaft portions 12a, 12b, 14b, 14c, and 14d have, for example, a bent or bent portion or a branched portion at least at one point. You may do it.

The base portion 111, the shaft portions 12a and 12b, the frame body portion 13, the shaft portions 14a, 14b, 14c and 14d, and the support portion 15 as described above are integrally formed.
In the present embodiment, the base 111, the shaft portions 12a and 12b, the frame body portion 13, the shaft portions 14a, 14b, 14c and 14d, and the support portion 15 are composed of the first Si layer (device layer) and the SiO ₂ layer (box Layer) and a second Si layer (handle layer) are formed by etching the SOI substrate. Thereby, the vibration characteristics of the first vibration system and the second vibration system can be made excellent. Further, since the SOI substrate can be finely processed by etching, the base portion 111, the shaft portions 12a and 12b, the frame body portion 13, the shaft portions 14a, 14b, 14c, and 14d and the support portion 15 are formed using the SOI substrate. By forming, the dimensional accuracy can be made excellent, and the optical scanning unit 42 can be downsized.

  The base 111, the shafts 12a and 12b, and the shafts 14a, 14b, 14c, and 14d are each configured by a first Si layer of an SOI substrate. Thereby, the elasticity of shaft part 12a, 12b and shaft part 14a, 14b, 14c, 14d can be made excellent. Further, it is possible to prevent the base 111 from coming into contact with the frame body portion 13 when rotating around the Y1 axis.

Further, the frame body portion 13 and the support portion 15, respectively, a first Si layer of the SOI substrate, and a stack of the SiO ₂ layer and the second Si layer. Thereby, the rigidity of the frame part 13 and the support part 15 can be made excellent. In addition, the SiO ₂ layer and the second Si layer of the frame body portion 13 not only function as ribs that increase the rigidity of the frame body portion 13 but also prevent the movable mirror portion 11 from contacting the permanent magnet 16. Also have.

Further, the upper surface of the support portion 15 is preferably subjected to an antireflection treatment. Thereby, it can prevent that the unnecessary light irradiated to the support part 15 turns into a stray light.
The antireflection treatment is not particularly limited, and examples thereof include formation of an antireflection film (dielectric multilayer film), roughening treatment, and black treatment.
Note that the above-described constituent materials and forming methods of the base portion 111, the shaft portions 12a and 12b, and the shaft portions 14a, 14b, 14c, and 14d are merely examples, and the present invention is not limited thereto.

In this embodiment, the spacer 112 and the light reflecting plate 113 are also formed by etching the SOI substrate. The spacer 112 is composed of a laminate composed of the SiO ₂ layer and the second Si layer of the SOI substrate. The light reflecting plate 113 is composed of a first Si layer of an SOI substrate.
Thus, by forming the spacer 112 and the light reflecting plate 113 using the SOI substrate, the spacer 112 and the light reflecting plate 113 joined to each other can be manufactured easily and with high accuracy.
Such a spacer 112 is bonded to the base 111 by a bonding material (not shown) such as an adhesive or a brazing material.

The permanent magnet 16 is joined to the lower surface (the surface opposite to the light reflecting plate 113) of the frame body 13 described above.
Although it does not specifically limit as a joining method of the permanent magnet 16 and the frame part 13, For example, the joining method using an adhesive agent can be used.
The permanent magnet 16 is magnetized in a direction inclined with respect to the X1 axis and the Y1 axis in plan view.

In the present embodiment, the permanent magnet 16 has a longitudinal shape (bar shape) extending in a direction inclined with respect to the X1 axis and the Y1 axis. The permanent magnet 16 is magnetized in the longitudinal direction. That is, the permanent magnet 16 is magnetized so that one end is an S pole and the other end is an N pole.
Further, the permanent magnet 16 is provided so as to be symmetric about the intersection of the X1 axis and the Y1 axis in plan view.
In this embodiment, the case where the number of one permanent magnet is installed in the frame body portion 13 will be described as an example. However, the present invention is not limited to this. For example, two permanent magnets are installed in the frame body portion 13. Also good. In this case, for example, two long permanent magnets may be installed on the frame body portion 13 so as to face each other via the base portion 111 in a plan view and to be parallel to each other.

The inclination angle θ in the magnetization direction (extending direction) of the permanent magnet 16 with respect to the X1 axis is not particularly limited, but is preferably 30 ° or more and 60 ° or less, and more preferably 45 ° or more and 60 ° or less. 45 ° is more preferable. By providing the permanent magnet 16 in this manner, the movable mirror portion 11 can be smoothly and reliably rotated around the X1 axis.
As such a permanent magnet 16, for example, a neodymium magnet, a ferrite magnet, a samarium cobalt magnet, an alnico magnet, a bond magnet, or the like can be suitably used. Such a permanent magnet 16 is obtained by magnetizing a hard magnetic material, and is formed, for example, by magnetizing a hard magnetic material before magnetization in the frame body portion 13. This is because if the permanent magnet 16 that has already been magnetized is to be installed in the frame portion 13, the permanent magnet 16 may not be installed at a desired position due to the influence of the magnetic field of the outside or other components.

A coil 17 is provided immediately below the permanent magnet 16. That is, the coil 17 is provided so as to face the lower surface of the frame body portion 13. Thereby, the magnetic field generated from the coil 17 can be applied to the permanent magnet 16 efficiently. Thereby, power saving and size reduction of the optical scanning unit 42 can be achieved.
Such a coil 17 is electrically connected to the signal superimposing unit 18 (see FIG. 6).
Then, when a voltage is applied to the coil 17 by the signal superimposing unit 18, a magnetic field having a magnetic flux orthogonal to the X1 axis and the Y1 axis is generated from the coil 17.
The signal superimposing unit 18 includes an adder (not shown) that superimposes the first drive signal V 1 and the second drive signal V 2 described above, and applies the superimposed voltage to the coil 17.

Here, the first drive signal V1 and the second drive signal V2 will be described in detail.
As described above, the drive circuit 321 generates the first drive signal V1 (horizontal scanning voltage) that periodically changes at the cycle T1, as shown in FIG. That is, the drive circuit 321 generates the first drive signal V1 having the first frequency (1 / T1).
The first drive signal V1 has a waveform like a sine wave. Therefore, the light scanning unit 42 can effectively perform main scanning with light. Note that the waveform of the first drive signal V1 is not limited to this.
The first frequency (1 / T1) is not particularly limited as long as it is suitable for horizontal scanning, but is preferably 10 to 40 kHz.

  In the present embodiment, the first frequency is set to be equal to the torsional resonance frequency (f1) of the first vibration system (torsional vibration system) composed of the movable mirror portion 11 and the pair of shaft portions 12a and 12b. Has been. That is, the first vibration system is designed (manufactured) so that its torsional resonance frequency f1 is a frequency suitable for horizontal scanning. Thereby, the rotation angle around the Y1 axis of the movable mirror portion 11 can be increased.

On the other hand, as described above, the drive circuit 322 generates the second drive signal V2 (vertical scanning voltage) that periodically changes at a period T2 different from the period T1, as shown in FIG. 4B. It is. That is, the drive circuit 322 generates the second drive signal V2 having the second frequency (1 / T2).
The second drive signal V2 has a sawtooth waveform. Therefore, the optical scanning unit 42 can effectively perform vertical scanning (sub-scanning) of light. Note that the waveform of the second drive signal V2 is not limited to this.

  The second frequency (1 / T2) is not particularly limited as long as it is different from the first frequency (1 / T1) and is suitable for vertical scanning, but is preferably 30 to 80 Hz (about 60 Hz). . As described above, the frequency of the second drive signal V2 is set to about 60 Hz, and the frequency of the first drive signal V1 is set to 10 to 40 kHz as described above, so that the movable mirror has a frequency suitable for drawing on the display. The part 11 can be rotated around each of two axes (X1 axis and Y1 axis) orthogonal to each other. However, the combination of the frequency of the first drive signal V1 and the frequency of the second drive signal V2 is not particularly limited as long as the movable mirror unit 11 can be rotated around the X1 axis and the Y1 axis. .

In the present embodiment, the frequency of the second drive signal V2 includes the movable mirror unit 11, the pair of shaft portions 12a and 12b, the frame body portion 13, the two pairs of shaft portions 14a, 14b, 14c and 14d, and the permanent magnet 16. It is adjusted to have a frequency different from the torsional resonance frequency (resonance frequency) of the second vibration system (torsional vibration system) constituted by
The frequency (second frequency) of the second drive signal V2 is preferably smaller than the frequency (first frequency) of the first drive signal V1. That is, the period T2 is preferably longer than the period T1. Accordingly, the movable mirror portion 11 can be rotated around the X1 axis at the second frequency while being rotated around the Y1 axis more reliably and smoothly.

  Further, when the torsional resonance frequency of the first vibration system is f1 [Hz] and the torsional resonance frequency of the second vibration system is f2 [Hz], f1 and f2 satisfy the relationship of f2 <f1. Is preferable, and it is more preferable to satisfy the relationship of f1 ≧ 10f2. Thereby, the movable mirror part 11 can be rotated more smoothly around the X1 axis at the frequency of the second drive signal V2 while being rotated more smoothly around the Y1 axis. . On the other hand, when f1 ≦ f2, the vibration of the first vibration system may occur due to the second frequency.

  Next, a driving method of the optical scanning unit 42 will be described. In the present embodiment, as described above, the frequency of the first drive signal V1 is set equal to the torsional resonance frequency of the first vibration system, and the frequency of the second drive signal V2 is the second frequency. Is set to a value different from the torsional resonance frequency of the vibration system and lower than the frequency of the first drive signal V1 (for example, the frequency of the first drive signal V1 is 15 kHz, the second drive The frequency of the signal V2 is set to 60 Hz).

For example, the first drive signal V1 as shown in FIG. 4A and the second drive signal V2 as shown in FIG. 4B are superimposed by the signal superimposing unit 18, and the superimposed voltage is coiled. 17 is applied.
Then, one end portion (N pole) of the permanent magnet 16 tries to be attracted to the coil 17 by the first drive signal V1, and the other end portion (S pole) of the permanent magnet 16 is about to be separated from the coil 17. While trying to separate the magnetic field (this magnetic field is called “magnetic field A1”) and one end (N pole) of the permanent magnet 16 from the coil 17, the other end (S pole) of the permanent magnet 16 is attracted to the coil 17. The intended magnetic field (this magnetic field is referred to as "magnetic field A2") is switched alternately.

  Here, as described above, the permanent magnet 16 is arranged so that each end (magnetic pole) is located in two regions divided by the Y1 axis. That is, in the plan view of FIG. 5, the north pole of the permanent magnet 16 is located on one side of the Y1 axis, and the south pole of the permanent magnet 16 is located on the other side. Therefore, by alternately switching between the magnetic field A1 and the magnetic field A2, vibration having a torsional vibration component around the Y1 axis is excited in the frame body portion 13, and the shaft portions 12a and 12b are twisted and deformed along with the vibration. Meanwhile, the movable mirror portion 11 rotates around the Y1 axis at the frequency of the first drive signal V1.

  The frequency of the first drive signal V1 is equal to the torsional resonance frequency of the first vibration system. Therefore, the movable mirror part 11 can be efficiently rotated around the Y1 axis by the first drive signal V1. That is, even if the vibration having the torsional vibration component around the Y1 axis of the frame body portion 13 described above is small, the rotation angle of the movable mirror portion 11 around the Y1 axis associated with the vibration can be increased.

  On the other hand, one end (N pole) of the permanent magnet 16 tries to be attracted to the coil 17 and the other end (S pole) of the permanent magnet 16 tries to be separated from the coil 17 by the second drive signal V2. A magnetic field (this magnetic field is referred to as “magnetic field B1”) and one end (N pole) of the permanent magnet 16 are separated from the coil 17, and the other end (S pole) of the permanent magnet 16 is attracted to the coil 17. The intended magnetic field (this magnetic field is referred to as "magnetic field B2") is switched alternately.

Here, as described above, the permanent magnet 16 is arranged so that each end (magnetic pole) is located in two regions divided by the X1 axis. That is, in the plan view of FIG. 5, the N pole of the permanent magnet 16 is located on one side of the X1 axis, and the S pole of the permanent magnet 16 is located on the other side. For this reason, the magnetic field B1 and the magnetic field B2 are alternately switched, so that the shaft body 14a and the shaft parts 14c and 14d are torsionally deformed, and the frame body part 13 together with the movable mirror part 11 is connected to the second drive signal. It rotates around the X1 axis at a frequency of V2.
Further, the frequency of the second drive signal V2 is set to be extremely lower than the frequency of the first drive signal V1. The torsional resonance frequency of the second vibration system is designed to be lower than the torsional resonance frequency of the first vibration system. Therefore, it is possible to prevent the movable mirror unit 11 from rotating around the Y1 axis at the frequency of the second drive signal V2.

According to the optical scanning unit 42 described above, the movable mirror unit 11 including the light reflecting unit 114 having light reflectivity is oscillated around two axes orthogonal to each other, so that the optical scanning unit 42 can be downsized. In addition, the weight can be reduced.
The signal light (scanning light) scanned by the optical scanning unit 42 is collected by the lens 43 and travels toward the magnifying optical unit 5 (see FIG. 2).

(Magnification optics)
The magnifying optical unit 5 includes a first light guide plate (first light guide unit) 51, a second light guide plate (second light guide unit) 52 on which a hologram 54 is formed, and a mirror unit 53. . The magnifying optical unit 5 has a function of expanding the image light emitted from the scanning light emitting unit 4 two-dimensionally. Hereinafter, the magnifying optical unit 5 will be described in detail. In the following, in the plan view of the magnifying optical unit 5, the incident direction in which the image light enters the magnifying optical unit 5 in the width direction of the second light guide plate 52 (the vertical direction in FIG. 7A and FIG. 8). And

  As shown in FIG. 7A, the first light guide plate 51 has an elongated shape and a pair of side surfaces 513 facing the width direction of the first light guide plate 51 (the thickness direction of the magnifying optical unit 5). 514, a first main surface (first reflective surface) 511 and a second surface facing each other in the thickness direction of the first light guide plate 51 (the direction orthogonal to the width direction and the longitudinal direction of the first light guide plate 51). Main surface 512. The first main surface 511 and the second main surface 512 are parallel, and the side surface 513 and the side surface 514 are parallel. In the present specification, “parallel” means that the angle formed by each surface is ± 2 ° or less, more preferably 0.2 ° or less.

A second light guide plate 52 is fixed to the second main surface 512 of the first light guide plate 51.
The second light guide plate 52 has an elongated shape, a pair of first main surface 521 and second main surface 522 that face each other in the thickness direction of the second light guide plate 52, and the second light guide plate 52. A pair of side surfaces 523 and 524 opposed to each other in the width direction, and a pair of end surfaces 525 and 526 opposed to each other in the longitudinal direction of the second light guide plate 52. The first main surface 521 and the second main surface 522 are parallel, and the side surface 523 and the side surface 524 are parallel. The end surface 525 is provided to be inclined with respect to the width direction (incident direction) of the second light guide plate 52, and the shape thereof is substantially the same as the shape of the second main surface 512 of the first light guide plate 51. equal. On the other hand, the end surface 526 is provided substantially perpendicular to the longitudinal direction of the second light guide plate 52.

  The inclination angle θ1 of the end surface 525 is preferably 20 ° or more and 70 ° or less, more preferably 40 ° or more and 50 ° or less, and particularly preferably 45 °. Thus, when the light L is incident on the magnifying optical unit 5 along the direction perpendicular to the longitudinal direction of the second light guide plate 52, the light L is guided along the longitudinal direction of the second light guide plate 52. Can be lighted. Therefore, the incident angle can be easily adjusted.

In addition, the first main surface 521 of the second light guide plate 52 receives light guided through the second light guide plate 52 on the outer side of the second light guide plate 52 (the front side in FIG. 7A). A hologram 54 is provided as a light extraction portion to be extracted. The hologram 54 has a width in the longitudinal direction of the second light guide plate 52 and a height in the width direction of the second light guide plate 52. The hologram 54 is a partially reflective transmission film having a property of diffracting light in a specific wavelength band and transmitting light in other wavelength bands. The hologram 54 forms a virtual image for image light in a specific wavelength band by adjusting the incident angle and the light flux state to be a desired one using diffraction, and external light in a wide wavelength band. For most of its components. By using the hologram 54 as the light extraction unit, it is possible to easily change the traveling direction of the light, and to provide the virtual image display device 1 having excellent light utilization efficiency.
The first light guide plate 51 and the second light guide plate 52 have the second main surface 512 of the first light guide plate 51 and the end surface 525 of the second light guide plate 52 fixed to each other. The width direction of the light guide plate 51 coincides with the thickness direction of the second light guide plate 52.

The mirror unit 53 has a plate shape, is on the second main surface 512 side of the second light guide plate 52, and near the boundary between the side surface 524 and the end surface 525 (before the traveling direction of the light L on the high transmission surface 300). Side). Further, the upper surface (light incident side reflection surface) 531 of the mirror unit 53 is a total reflection surface that totally reflects light. In this specification, the “total reflection surface” naturally includes a surface with a light transmittance of 0%, but also includes a surface that transmits light slightly (for example, about 3%).
In such a magnifying optical unit 5, the first main surface 511 and the side surfaces 513 and 514 of the first light guide plate 51, the first main surface 521, the second main surface 522 and the side surfaces of the second light guide plate 52. Reference numerals 523 and 524 denote total reflection surfaces that totally reflect incident light.

  As shown in FIG. 8, a partially transmissive reflection surface (second reflection surface) 200 is formed between the first light guide plate 51 and the second light guide plate 52. In the present embodiment, the partially transmissive reflecting surface 200 is formed on the second main surface 512 of the first light guide plate 51. The partially transmissive reflecting surface 200 is formed in a portion (a surface indicated by a thick line in FIG. 8A) excluding both end portions of the second main surface 512 of the first light guide plate 51. The partially transmissive reflecting surface 200 reflects a part of the incident light and transmits a part of the incident light. The partially transmissive reflecting surface 200 may be formed on the end surface 525 of the second light guide plate 52.

The method of forming the partially transmissive reflecting surface 200 is not particularly limited, and examples thereof include a method of depositing a metal film such as Cr or Ag, a dielectric film, a hybrid film combining these, and the like.
Moreover, in the partially transmissive reflective surface 200, the light transmittance of the lower end part in FIG. 8 is 5% or more and 10% or less, and the light transmittance of the upper end part in FIG. 8 is 12% or more and 17% or less. Further, the partially transmissive reflecting surface 200 is configured such that the light transmittance gradually increases as the distance from the high transmissive surface (light incident portion) 300, which will be described later, increases in the portion between both ends. Examples of a method having such a configuration include a method of adjusting the thickness of the metal film, the dielectric film, or the hybrid film.

  Further, the light transmittance is higher than that of the partially transmissive reflecting surface 200 at both ends of the partially transmissive reflecting surface 200 (regions where the partially transmissive reflecting surface 200 of the second main surface 512 of the first light guide plate 51 is not formed). High transmission surfaces 300 and 400 having a high height are formed. The high transmission surface 300 is located on the side surface 524 side of the partial transmission reflection surface 200, and the high transmission surface 400 is located on the side surface 523 side of the partial transmission reflection surface 200. The light transmittance of the high transmission surfaces 300 and 400 is preferably 95% or more.

  Here, the principle that the light emitted from the scanning light emitting unit 4 is two-dimensionally enlarged by the magnifying optical unit 5 will be described. In the following description, the amount of attenuation when light is reflected by the total reflection surface is sufficiently small with respect to the amount of light incident on the total reflection surface, and thus the amount of attenuation is ignored. Further, when light is guided through the first light guide plate 51, the light is repeatedly reflected from the first main surface 511, the second main surface 512, and the side surfaces 513, 514 while repeating the first guide. Although the light is guided through the optical plate 51, for convenience of explanation, light is guided through the first light guide plate 51 while being repeatedly reflected between the first main surface 511 and the second main surface 512. . Similarly, when light is guided through the second light guide plate 52, the light repeats total reflection between the first main surface 521, the second main surface 522, and the side surfaces 523 and 524, and the first Although light is guided through the light guide plate 51, for convenience of explanation, light is guided through the second light guide plate 52 while being repeatedly reflected between the first main surface 521 and the second main surface 522. To do.

  First, the light emitted from the scanning light emitting unit 4 is reflected by the mirror unit 53 and enters the first light guide plate 51 through the side surface 524 of the second light guide plate 52 and the high transmission surface 300. As described above, since the high transmittance surface 300 has a light transmittance greater than 95%, most of the light can enter the first light guide plate 51. Further, when the light is incident on the magnifying optical unit 5, if it is directly incident on the side surface 524 without passing through the mirror unit 53, the light needs to be incident on a relatively narrow region of the side surface 524 with high accuracy. However, in this embodiment, since light is incident on the magnifying optical unit 5 via the mirror unit 53, the light can be incident on the side surface 524 and the high transmission surface 300 as long as the light is incident on a relatively wide area. it can. In addition, it is preferable that the incident angle of the light with respect to the upper surface 531 of the mirror part 53 is 0 degree or more and 20 degrees or less, and it is more preferable that it is 0 degree or more and 10 degrees or less.

  As shown in FIG. 8A, the light L that has passed through the high transmission surface 300 is reflected by the portion 511 </ b> A of the first main surface 511 and travels toward the partial transmission reflection surface 200. A part of the light L that has reached the portion 200A of the partially transmissive reflecting surface 200 is reflected and travels toward the first main surface 511 again as light L1. Then, a part (remaining part) of the light L reaching the part 200A of the partially transmissive reflecting surface 200 is incident on the second light guide plate 52 as the light L2.

  As shown in FIG. 8B, the light L1 directed toward the first main surface 511 is reflected by the portion 511B on the downstream side in the light traveling direction from the portion 511A of the first main surface 511, and is partially transmitted again. It faces the reflecting surface 200. The light L1 that has reached the portion 200B on the downstream side in the light traveling direction with respect to the portion 200A of the transmission / reflection surface 200 is partially reflected in the same manner as described above, and is again reflected on the first main surface 511 as light L3. Head over. The remaining portion of the light L1 that has reached the portion 200B of the partially transmissive reflecting surface 200 is incident on the second light guide plate 52 as light L4.

In this way, while repeating total reflection and partial reflection, the light L is guided through the first light guide plate 51 and also enters the second light guide plate 52. Further, the light (light L <b> 2 to light Lx) incident on the second light guide plate 52 is repeatedly totally reflected between the first main surface 521 and the second main surface 522 of the second light guide plate 52. Light is guided from the left side in FIG. 8 to the right side in FIG. A part of the light L2 to the light Lx is extracted to the outside of the second light guide plate 52 by the hologram 54, and the observer can visually recognize it as a virtual image. At this time, as illustrated in FIG. 7B, the light L <b> 2 to the light Lx are multiple-reflected between the hologram 54 and the second main surface 522. A part of the light L <b> 2 to the light Lx passes through the hologram 54 and is emitted to the outside of the second light guide plate 52 along the thickness direction of the second light guide plate 52.
In this way, the light L2 to the light Lx are expanded in the width direction of the hologram 54 (longitudinal direction of the second light guide plate 52).

Here, the light incident on the second light guide plate 52 is attenuated with increasing distance from the high transmission surface 300 when the light transmittance of the partial transmission reflection surface 200 is constant over the entire length in the longitudinal direction of the partial transmission reflection surface 200. To do. That is, when the light transmittance of the partially transmissive reflecting surface 200 is constant over the entire length in the longitudinal direction of the partially transmissive reflecting surface 200, the amount of light incident on the second light guide plate 52 is in the order of light L2 to light Lx. Decreases and decreases. However, as described above, the partially transmissive reflecting surface 200 is configured such that the light transmittance gradually increases as the light transmittance increases away from the high transmissive surface 300. For this reason, for example, the light L4 is transmitted through a portion of the partially transmissive reflecting surface 200 having a higher light transmittance than the portion through which the light L2 is transmitted. As a result, the difference between the light quantity of the light L2 and the light quantity of the light L4 can be made as small as possible. Therefore, the amount of light (light L2 to light Lx) incident on the second light guide plate 52 can be made as uniform as possible. Therefore, it is possible to reduce unevenness of the virtual image displayed by the hologram.
Furthermore, the light Lx is light having a large attenuation amount among the light L2 to the light Lx. However, as shown in FIG. 8B, since the light Lx passes through the high transmission surface 400, the amount of light (light L2 to light Lx) incident on the second light guide plate 52 is more effectively reduced. It can be made substantially uniform.

In addition, as a material which comprises the 1st light-guide plate 51 and the 2nd light-guide plate 52, respectively, if it has light transmittance, respectively, it will not specifically limit, For example, various resin, such as an acryl and an epoxy resin, Various glasses can be used.
In this way, the magnifying optical unit 5 expands the light L in the vertical direction in FIG. 8 with the first light guide plate 51 and expands in the horizontal direction in FIG. 8 with the second light guide plate 52 (hologram 54). That is, the magnifying optical unit 5 can magnify the light L two-dimensionally. In the magnifying optical unit 5, the first main surface 511 of the first light guide plate 51 and the partially transmitting / reflecting surface 200 are arranged to face each other so as to be parallel to each other, and the light is two-dimensionally arranged. Can be expanded.

  Further, when the magnifying optical unit 5 is manufactured, the two surfaces (the first main surface 511 and the second main surface 512 of the first light guide plate 51) may be adjusted so as to be parallel to each other. Compared with the method of adjusting so that a large number of surfaces are parallel to each other, it can be manufactured very easily. In this embodiment, the magnifying optical unit 5 can be manufactured by a simple method in which the first light guide plate 51 having a constant thickness is fixed to the end surface 525 of the second light guide plate 52.

Second Embodiment
Next, a second embodiment of the virtual image display device of the present invention will be described.
FIG. 9 is a plan view showing a second embodiment of the virtual image display device (optical element) of the present invention.
Hereinafter, the second embodiment will be described with a focus on the differences from the first embodiment described above, and the description of the same matters will be omitted.
The virtual image display device of this embodiment is the same as the virtual image display device of the first embodiment except that the configuration of the magnifying optical unit is different.

  As shown in FIG. 9, in the magnifying optical unit 5 </ b> A of the virtual image display device 1 </ b> A of the present embodiment, the first light guide plate 51 has end faces 515 and 516 parallel to each other and in the longitudinal direction of the first light guide plate 51. It is inclined and provided. In addition, the end surface 515 of the first light guide plate 51 and the side surface 523 of the second light guide plate 52 are located on the same plane in a state where the first light guide plate 51 and the second light guide plate 52 are fixed. The end surface 516 of the first light guide plate 51 and the side surface 524 of the second light guide plate 52 are located on the same plane. Further, the partial transmission / reflection surface 200 is provided on the entire surface of the second main surface 512 of the first light guide plate 51.

In the present embodiment, the light L is directly incident on the first light guide plate 51 from the end surface 516 of the first light guide plate 51 without using the second light guide plate 52. According to such a configuration, the high transmission surface 300 can be omitted. Therefore, the configuration of the magnifying optical unit 5A can be further simplified.
Further, the magnifying optical unit 5A can also be obtained by a simple method of removing a part of the magnifying optical unit 5 of the first embodiment (a portion 500A indicated by a two-dot chain line in FIG. 9) by, for example, etching.

<Third Embodiment>
Next, a third embodiment of the virtual image display device of the present invention will be described.
FIG. 10 is a plan view showing a third embodiment of the virtual image display device (optical element) of the present invention.
Hereinafter, the third embodiment will be described with a focus on differences from the first embodiment described above, and descriptions of the same matters will be omitted.
The virtual image display device of this embodiment is the same as the virtual image display device of the first embodiment except that the configuration of the magnifying optical unit is different.

As shown in FIG. 10, in the magnifying optical unit 5B of the virtual image display device 1B of the present embodiment, the inclination angle θ2 of the partially transmissive reflecting surface 200 with respect to the width direction of the second light guide plate 52 is 20 ° or more and 40 ° or less. is there. In the present embodiment, the inclination angle θ2 is 30 °. In addition, the incident direction of the light L with respect to the magnifying optical unit 5B is the same as that in the first embodiment so that the light guided in the second light guide plate 52 is substantially parallel to the longitudinal direction of the second light guide plate 52. It is inclined with respect to the incident direction. The mirror unit 53 is also inclined at the same angle as the incident direction of the light L.
According to such a configuration, the same effect as that of the first embodiment can be obtained, and the inclined portion 500B can be made smaller than that of the first embodiment because the inclination angle θ2 is small. Therefore, the length of the magnifying optical unit 5B can be shortened, and the size of the virtual image display device 1B can be reduced.

<Fourth embodiment>
Next, a fourth embodiment of the virtual image display device of the present invention will be described.
FIG. 11 is a plan view showing a fourth embodiment of the virtual image display device (optical element) of the present invention.
Hereinafter, the fourth embodiment will be described with a focus on differences from the second embodiment described above, and description of similar matters will be omitted.
The virtual image display device according to the present embodiment is substantially the same as the virtual image display device according to the second embodiment except that the method for making light incident on the magnifying optical unit is different.

As shown in FIG. 11, in the virtual image display device 1 </ b> C of the present embodiment, light L is incident on the first light guide plate 51 and the second light guide plate 52 with respect to the magnifying optical unit 5 </ b> C. Specifically, a part of the light L incident on the magnifying optical unit 5C is incident on the first light guide plate 51 and is multiple-reflected between the first main surface 511 and the partially transmissive reflecting surface 200, Reflection and transmission are repeated on the partially transmissive reflecting surface 200. On the other hand, the light incident on the second light guide plate 52 directly enters the partially transmissive reflecting surface 200. A part of the light L incident on the partially transmissive reflecting surface 200 is transmitted and incident on the first light guide plate 51 and subjected to multiple reflection as described above, and the remainder of the light L incident on the partially transmissive reflecting surface 200 is Reflected and conducted through the second light guide plate 52.
According to such a configuration, light having a relatively large diameter can be incident on the magnifying optical unit 5C. Further, when the light L is incident on the magnifying optical unit 5, the light L can be extracted from the hologram 54 even if the position of the light L is slightly shifted in the longitudinal direction of the magnifying optical unit 5.

<Fifth Embodiment>
Next, a fourth embodiment of the virtual image display device of the present invention will be described.
FIG. 12 is a plan view showing a fifth embodiment of the virtual image display device (optical element) of the present invention.
Hereinafter, the fourth embodiment will be described with a focus on differences from the second embodiment described above, and description of similar matters will be omitted.
The virtual image display device of this embodiment is substantially the same as the virtual image display device of the second embodiment except that the configuration of the magnifying optical unit is different.

As shown in FIG. 12, in the magnifying optical unit 5D of the virtual image display device 1D of the present embodiment, the second light guide plate 52 is removed by removing a part (part 500D) of the magnifying optical unit 5A of the second embodiment. An end face 501 parallel to the width direction is formed. The end surface 501 is provided across the first light guide plate 51 and the second light guide plate 52.
In the present embodiment, the light L is incident on the first light guide plate 51 and the second light guide plate 52 from the end surface 501. The incident direction of the light L to the magnifying optical unit 5D is parallel to the longitudinal direction of the second light guide plate 52 in a plan view of the magnifying optical unit 5D.

The light L incident on the first light guide plate 51 is subjected to multiple reflections between the partially transmissive reflection surface 200 and the first main surface 511 of the first light guide plate 51 and repeats reflection and transmission. The light L transmitted through the partially transmissive reflecting surface 200 is guided through the second light guide plate 52. On the other hand, the light incident on the second light guide plate 52 is guided through the second light guide plate 52 as it is.
Thus, the light incident direction can be selected depending on the position where the end surface 501 is formed and the tilt angle. Thereby, the freedom degree of arrangement | positioning of the scanning light emission part 4 can be improved. Therefore, the freedom degree of design of virtual image display apparatus 1D can be raised.

<Sixth Embodiment>
Next, a sixth embodiment of the virtual image display device of the present invention will be described.
FIG. 13 is a view showing a sixth embodiment of the virtual image display device (optical element) of the present invention, where (a) is a plan view and (b) is a view seen from the direction of arrow A in (a).
Hereinafter, the sixth embodiment will be described focusing on the differences from the third embodiment described above, and description of similar matters will be omitted.
The virtual image display device of this embodiment is substantially the same as the virtual image display device of the first embodiment except that the configuration of the magnifying optical unit is different.

As shown in FIGS. 13A and 13B, the magnifying optical unit 5E of the virtual image display device 1E of the present embodiment includes a first plate member 51E, a second plate member 52E, a first member 53E, and a second member. 54E.
The first plate member 51E has substantially the same shape as the second light guide plate 52 of the third embodiment.

The second plate 52E is provided to face the first plate 51E, and can be divided into a left portion 520A in FIG. 13B and a right portion 520B in FIG. The portion 520A has a portion overlapping the first plate member 51E and a portion protruding from the first plate member 51E to the lower side in FIG. 13A (mirror portion 55E) in a plan view of the magnifying optical unit 5E. doing. The portion 520B is configured by a plate material having substantially the same width as the first plate material 51E.
The first plate material 51E and the second plate material 52E are provided so as to be parallel to each other.

  The first member 53E has a rectangular bar shape in cross section, and is provided on the upper surface of the second plate member 52E and on the left side of the first plate member 51E in the drawing. The second member 54E has a rectangular bar shape in cross section, and is provided between the first plate member 51E and the second plate member 52E and on the right side of the first member 53E in the drawing. The second member 54E functions as a spacer that holds the first plate member 51E and the second plate member 52E apart from each other. Further, the first member 53E and the second member 54E are provided in parallel.

  The separation distance D1 between the first plate member 51E and the second plate member 52E and the separation distance D2 between the first member 53E and the second member 54E may be the same or different. The separation distance D1 and the separation distance D2 are preferably about 0.5 mm or more and 10 mm, and more preferably 2 mm or more and 8 mm or less. Thereby, the magnifying optical part 5E can be thinned.

In the magnifying optical unit 5E, the first plate member 51E, the second plate member 52E, the first member 53E, and the second member 54E are made of a light transmissive material.
As shown in FIG. 13B, the main surface 511E of the first plate member 51E on the second plate member 52E side is the total reflection surface up to the middle in the longitudinal direction (the region indicated by the thick line in FIG. 13B). The remaining portion (the area hatched in FIG. 13B) is a partially transmissive reflecting surface (third reflecting surface) 200. Further, the main surface (fourth reflective surface) 521E of the second plate material 52E on the first plate material 51E side is the total reflection surface. Further, the entire surface 531E of the first member 53E on the second member 54E side is a total reflection surface, and the entire surface of the surface 541E of the second member 54E on the first member 53E side (the hatched line in FIG. 13B is shown). The attached surface) is a partially transmissive reflecting surface 200.
In such a magnifying optical unit 5E, the space S1 defined by the main surfaces 511E and 521E and the surfaces 531E and 541E functions as a first light guide unit. In addition, the space S2 on the right side in the drawing with respect to the second member 54E between the main surface 511E of the first plate member 51E and the main surface 521E of the second plate member 52E functions as a second light guide.

As illustrated, the light L is inclined with respect to the width direction and the thickness direction of the magnifying optical unit 5 and is incident from above. At this time, the light is reflected by the mirror 55E and is incident on the space S1.
The light L incident on the space S1 is guided through the space S1 toward the back side of the paper surface in FIG. 13B while being subjected to multiple reflections between the main surfaces 511E and 521E and the surfaces 531E and 541E. At this time, since the surface 541E is a partially reflecting / transmitting surface, a part of the light L incident on the surface 541 enters the space S2.

  The light L incident on the space S2 is guided to the right side in FIG. 13 by repeating total reflection between the main surface 511E of the first plate material 51E and the main surface 521E of the second plate material 52E. Since the main surface 511E of the first plate member 51E is the partially transmissive reflecting surface 200 from the middle, a part of the light L that is repeatedly guided to the partially transmissive reflecting surface 200 is partially reflected by the partially transmissive reflecting surface 200. Part of the light passes through and exits outside the space S2. The remaining portion is subjected to multiple reflections, and a part thereof is emitted to the outside of the space S2 in the same manner as described above while being guided to the right side of the space S2.

Thus, in this embodiment, since it becomes the partial transmission reflective surface 200 from the middle of the main surface 511E of the 1st board | plate material 51E, the part corresponding to the partial transmission reflection surface 200 of the 1st board | plate material 51E serves as a light extraction part. Can function. Therefore, the hologram 54 can be omitted, and the manufacture becomes easy. Furthermore, since the part corresponding to the partially transmissive reflection surface 200 of the first plate member 51E functions as a light extraction part, the observer can visually recognize a virtual image larger than the virtual image displayed on the hologram 54.
In the present embodiment, as shown in FIG. 13B, the observer preferably observes from the direction intersecting the thickness direction of the first plate member 51E and the second plate member 52E.

In this embodiment, the space S1 and the space S2 may be filled with a material having a refractive index smaller than the refractive index of each plate material.
In the present embodiment, at least the second plate member 52E and the second member 54E may be made of a light transmissive material, and the first plate member 51E and the first member 53E are made of a light transmissive material. It does not have to be.

<Seventh embodiment>
Next, a seventh embodiment of the virtual image display device of the present invention will be described.
FIG. 14 is a diagram illustrating an image forming unit included in the seventh embodiment of the virtual image display device (optical element) of the present invention.
Hereinafter, the seventh embodiment will be described with a focus on differences from the first embodiment described above, and description of similar matters will be omitted.
The virtual image display device of the present embodiment is the same as the virtual image display device of the first embodiment, except that the configuration of the image forming unit is different.

  As shown in FIG. 14, the image forming unit 10 </ b> A of the present embodiment is configured by a projector having a light source device 620, a uniform illumination optical system 630, a light modulation device (spatial light modulation device) 640, and a lens group 650. Has been. Such an image forming unit 10A forms an image by modulating the light emitted from the light source device 620 by the light modulation device 640 in accordance with a given image signal, and collects this image by the lens group 650. Then, the light enters the magnifying optical unit 5.

The light source device 620 includes an ultra-high pressure mercury lamp 621 that is a light source and a reflector 622. In such a configuration, the light emitted from the extra-high pressure mercury lamp 621 is reflected by the reflector 622 and converged to the front side. In addition, as a light source, you may employ | adopt not only an ultrahigh pressure mercury lamp but a metal halide lamp etc., for example.
The uniform illumination optical system 630 includes a rod integrator 631, a color wheel 632, a relay lens group 633, and a reflection mirror 634. In such a uniform illumination optical system 630, the light beam emitted from the light source device 620 passes through the color wheel 632 and then enters the rod integrator 631 at an angle.

  The color wheel 632 is rotatably provided by a driving source such as a motor (not shown). Further, the color wheel 632 is formed with a filter surface 632a facing a port formed at the incident side end of the rod integrator 631, and the filter surface 632a has R (red), G (green), B (blue) three-color filters are formed side by side in the circumferential direction across an area. The color wheel 632 may be provided on the emission side of the rod integrator 631.

The light beam incident on the color wheel 632 is color-separated in time series into three colors of red (R) light, green (G) light, and blue (B) light by the filter surface 632a.
The light (R light, G light, B light) that has passed through the color wheel 632 is introduced into the inside of the incident port of the rod integrator 631. The light introduced into the rod integrator 631 is reflected a plurality of times in the rod integrator 631, thereby ensuring a uniform illuminance on the exit surface of the rod integrator 631. Therefore, the light emitted from the emission port of the rod integrator 631 has a uniform illumination distribution.

The light emitted from the rod integrator 631 enters the light modulation device 640 as uniform illumination light via the relay lens group 633 and the reflection mirror 634.
The light modulation device 640 includes a substrate 641 and a plurality of light modulation elements 642 (for example, DMD (Digital Micromirror Device) arranged on the substrate 641. However, “DMD” is a product of Texas Instruments Incorporated. Registered trademark). The plurality of light modulation elements 642 are arranged in a matrix on the substrate 641. The number of light modulation elements 642 is not particularly limited. In the image forming unit 10A, since one light modulation element 642 constitutes one pixel, the light modulation elements 642 are arranged by the number of pixels, for example, horizontal × vertical = 1280 × 1024, 640 × 480. .
Each light modulation element 642 has a movable mirror for reflecting an incident light beam, and this movable mirror has a different inclination from the ON state in which the reflected light is guided to the lens group 650. The posture changes to an OFF state in which the reflected light is guided to an absorber (not shown).

The light modulation device 640 forms predetermined light by switching the ON / OFF state of each light modulation element 642 independently based on, for example, video information given from a PC (personal computer) or the like. The formed light is incident on the lens group 650.
The lens group 650 includes a condenser lens 651, and emits the light guided to the lens group 650 to the magnifying optical unit 5.
Also according to the seventh embodiment, the same effects as those of the first embodiment described above can be obtained.

<Eighth Embodiment>
Next, an eighth embodiment of the virtual image display device of the present invention will be described.
FIG. 15 is a diagram illustrating an image forming unit included in the eighth embodiment of the virtual image display device (optical element) of the present invention.
Hereinafter, the eighth embodiment will be described with a focus on differences from the first embodiment described above, and descriptions of the same matters will be omitted.
The virtual image display device of the present embodiment is the same as the virtual image display device of the first embodiment, except that the configuration of the image forming unit is different.

As shown in FIG. 15, the image forming unit 10B includes an illumination optical system 410, a color separation optical system 420, parallelizing lenses 430R, 430G, and 430B, spatial light modulators 440R, 440G, and 440B, and a cross dichroic prism. 450, a lens group 460, and a polarization rotator 470.
The illumination optical system 410 includes a light source 411, a reflector 412, a first lens array 413, a second lens array 414, a polarization conversion element 415, and a superimposing lens 416.

  The light source 411 is an ultra-high pressure mercury lamp, and the reflector 412 is configured to have a parabolic mirror. The radial light beam emitted from the light source 411 is reflected by the reflector 412 to become a substantially parallel light beam, and is emitted to the first lens array 413. The light source 411 is not limited to an ultrahigh pressure mercury lamp, and may be a metal halide lamp, for example. Further, the reflector 412 is not limited to a parabolic mirror, and a configuration in which a collimating concave lens is disposed on the exit surface of the reflector 412 made of an ellipsoidal mirror may be adopted.

  The first lens array 413 and the second lens array 414 are formed by arranging small lenses in a matrix. The light beam emitted from the light source 411 is divided into a plurality of minute partial light beams by the first lens array 413, and each partial light beam is divided into three spatial lights to be illuminated by the second lens array 414 and the superimposing lens 416. Superimposed on the surfaces of the modulation devices 440R, 440G, 440B.

The polarization conversion element 415 has a function of aligning a randomly polarized light beam with linearly polarized light (s-polarized light or p-polarized light) that vibrates in one direction. In this embodiment, the loss of the light beam in the color separation optical system 420 is reduced. There are few s-polarized light.
The color separation optical system 420 has a function of separating the light beam emitted from the illumination optical system 410 into three color lights of red (R) light, green (G) light, and blue (B) light, A B light reflecting dichroic mirror 421, an RG light reflecting dichroic mirror 422, a G light reflecting dichroic mirror 423, and reflecting mirrors 424 and 425 are provided.

  Of the light beam emitted from the illumination optical system 410, the B light component is reflected by the B light reflecting dichroic mirror 421 and further reflected by the reflecting mirrors 424 and 461 to reach the collimating lens 430B. On the other hand, among the light beams emitted from the illumination optical system 410, the components of G light and R light are reflected by the RG light reflecting dichroic mirror 422 and further reflected by the reflecting mirror 425 to reach the G light reflecting dichroic mirror 423. The G light component therein is reflected by the G light reflecting dichroic mirror 423 and the reflecting mirror 462 and reaches the collimating lens 430G, and the R light component is transmitted through the G light reflecting dichroic mirror 423 and reflected by the reflecting mirror 463. To the collimating lens 430R.

The collimating lenses 430R, 430G, and 430B allow the partial light beams from the illumination optical system 410 to become substantially parallel light beams so as to illuminate the spatial light modulators 440R, 440G, and 440B, respectively. Is set to
The R light transmitted through the collimating lens 430R reaches a spatial light modulation device (first spatial light modulation device) 440R, and the G light transmitted through the parallelizing lens 430G is a spatial light modulation device (second spatial light modulation device). The B light reaching 440G and transmitted through the collimating lens 430B reaches the spatial light modulation device (third spatial light modulation device) 440B.

  The spatial light modulation device 440R is a spatial light modulation device that modulates R light according to an image signal, and is a transmissive liquid crystal display device (LCD). A liquid crystal panel (not shown) provided in the spatial light modulation device 440R encloses a liquid crystal layer for modulating light according to an image signal between two transparent substrates. The R light modulated by the spatial light modulation device 440R enters a cross dichroic prism 450 that is a color synthesis optical system. The configurations and functions of the spatial light modulators 440G and 440B are the same as those of the spatial light modulator 440R.

  The cross dichroic prism 450 is formed into a prismatic shape with a substantially square cross section by bonding four triangular prisms, and dielectric multilayer films 451 and 452 are formed along the X-shaped bonding surface. Is provided. The dielectric multilayer film 451 transmits G light and reflects R light, and the dielectric multilayer film 452 transmits G light and reflects B light. Then, the cross dichroic prism 450 forms the image light representing the color image by combining the modulated lights of the respective color lights emitted from the spatial light modulators 440R, 440G, and 440B from the incident surfaces 450R, 450G, and 450B, respectively. Then, the image light is emitted toward the projection optical system 160.

  A polarization rotator 170 is disposed between the cross dichroic prism 450 and the lens group 460. The polarization rotator 170 has wavelength selectivity and functions to rotate the oscillation direction of light of a predetermined wavelength by 90 ° (that is, a function to convert s-polarized light to p-polarized light or p-polarized light to s-polarized light). have. Such a polarization rotator 170 is not particularly limited. For example, Color Select (registered trademark) manufactured by Coloring Co., Ltd. can be used.

  Since the cross dichroic prism 450 is a single polarization element that reflects s-polarized light and transmits p-polarized light, the R light and B light reflected by the cross dichroic prism 450 are converted to s-polarized light and G is transmitted through the cross dichroic prism 450. The light needs to be p-polarized light. Thus, since the polarization directions of the R light, B light, and G light are different, the polarization rotator 470 is arranged to align the polarization directions of the R light, G light, and B light.

The polarization rotator 470 is configured to rotate the polarization of the R light and the B light by 90 ° and not rotate the polarization of the G light. Therefore, the R light, G light, and B light that have passed through the polarization rotator 470 have the same vibration direction. Here, the G light is a component having a higher relative visibility than the R light and the B light. Therefore, unlike the polarization rotator 470, by rotating the polarizations of the R light and the B light without rotating the polarization of the G light, the polarizations of the R light, the G light, and the B light are aligned. A sufficient amount of luminous flux can be obtained, and a bright image can be displayed.
The image light that has passed through the polarization rotator 470 is condensed by the lens group 460 as light L and emitted to the magnifying optical unit 5.

Also according to the eighth embodiment, the same effects as those of the first embodiment described above can be obtained.
In the present embodiment, a projector using three transmissive liquid crystal display devices (LCD) has been described, but the configuration of the projector is not limited to this. For example, a configuration using three reflective liquid crystal display devices (LCD) may be used. In addition, a configuration using two liquid crystal display devices may be used regardless of transmission type / reflection type. In other words, the present embodiment can be applied to any projector that uses polarized light and uses two or more microdisplays.

<Ninth Embodiment>
Next, a ninth embodiment of the virtual image display device of the present invention will be described.
FIG. 16 is a diagram illustrating an image forming unit included in the ninth embodiment of the virtual image display device (optical element) of the present invention.
Hereinafter, the ninth embodiment will be described focusing on the differences from the first embodiment described above, and description of similar matters will be omitted.
The virtual image display device of the present embodiment is the same as the virtual image display device of the first embodiment, except that the configuration of the image forming unit is different.

As illustrated in FIG. 16, the image forming unit 10 </ b> C includes a projector having a light source unit 710, a PBS prism 730, a reflective liquid crystal panel 740, and a lens group 750.
The light source unit 710 includes red, green, and blue laser light sources 711R, 711G, and 711B, collimator lenses 712R, 712G, and 712B provided for the laser light sources 711R, 711G, and 711B and dichroic mirrors 713R, 713G, and 713B. And.

  The laser light sources 711R, 711G, and 711B each have a light source and a drive circuit (not shown). The laser light source 711R emits red laser light, the laser light source 711G emits green laser light, and the laser light source 711B emits blue laser light. The laser beams of the respective colors emitted from these laser light sources 711R, 711G, and 711B are linearly polarized light and have the same vibration direction (for example, S wave).

  The laser beams of the respective colors emitted from the laser light sources 711R, 711G, and 711B are collimated by the collimator lenses 712R, 712G, and 712B and enter the dichroic mirrors 713R, 713G, and 713B. The dichroic mirror 713R has a characteristic of reflecting red laser light. The dichroic mirror 713B has characteristics of reflecting blue laser light and transmitting red laser light. The dichroic mirror 713G has characteristics of reflecting green laser light and transmitting red and blue laser lights.

  The driving of the laser light sources 711R, 711G, and 711B is controlled so as to blink sequentially, whereby red laser light, green laser light, and blue laser light are sequentially emitted. The emitted laser light of each color passes through a collimator lens and a dichroic mirror, is reflected by a reflection surface of a PBS (polarization beam splitter) prism 730, and is projected on a reflective liquid crystal panel 740.

  The reflective liquid crystal panel 740 is an LCOS (Liquid Crystal on Silicon) and has a reflective layer. The laser beams of the respective colors reflected by the reflection layer and passed through the PBS prism 730 are condensed by the lens group 750 as image light (light L) and emitted to the magnifying optical unit 5. In addition, the laser light of each color reflected by the reflective liquid crystal panel 740 is rotated by 90 ° and becomes p-polarized light.

According to the ninth embodiment, the same effect as that of the first embodiment described above can be obtained.
In the present embodiment, the single-plate system using one reflective liquid crystal panel 740 is used, but the configuration of the image forming unit 10C is not limited to this. For example, a three-plate system in which a reflective liquid crystal panel is provided for each of red light, green light, and blue light, or a configuration using a transmissive liquid crystal panel instead of the reflective liquid crystal panel may be used. In addition, a projector in which light of each color from the light source unit 710 is linearly polarized in advance having only a vibration component in the same direction (for example, a polarization control type single-plate projector, a scan in which the vibration direction of each color of light is controlled) If it is a projector etc., it will not specifically limit as a structure of a projector.

<Tenth Embodiment>
Next, a tenth embodiment of the virtual image display device of the present invention will be described.
FIG. 17 is a diagram illustrating an image forming unit included in the tenth embodiment of the virtual image display device (optical element) of the present invention.
Hereinafter, the tenth embodiment will be described with a focus on differences from the first embodiment described above, and description of similar matters will be omitted.
The virtual image display device of the present embodiment is the same as the virtual image display device of the first embodiment, except that the configuration of the image forming unit is different.

As shown in FIG. 17, the image forming unit 10 </ b> D of the present embodiment is configured by an organic EL (electroluminescence) panel. Hereinafter, the organic EL element 100D constituting one pixel will be described.
The organic EL element 100D includes a glass substrate 104D, an anode layer 101D, an organic light emitting layer 102D containing a light emitting substance, and a cathode layer 103D. In the image forming unit 10D, an anode layer 101D is laminated on a glass substrate 104D, and an organic light emitting layer 102D for red light, an organic light emitting layer 102D for blue light, and an organic light emitting layer 102D for green light are formed thereon. Are stacked at different positions. A cathode layer 103D is disposed on the organic light emitting layer 102D for red light, the organic light emitting layer 102D for blue light, and the organic light emitting layer 102D for green light.

When a voltage is applied between the anode layer 101D and each cathode layer 103D, holes are injected from the anode layer 101D into each organic light emitting layer 102D, and electrons are injected from each cathode layer 103D into each organic light emitting layer 102D. The In each organic light emitting layer 102D, the injected electrons and holes are recombined in each organic light emitting layer 102D, and the excitation energy when the energy level returns from the conduction band to the valence band is released as light energy. Thereby, each organic light emitting layer 102D emits red (R), blue (B), and green (G) light, respectively.
Such an organic EL element 100D is connected to a control unit (not shown), and its driving is controlled by this control unit.

In the image forming unit 10D, since one organic EL element 100D constitutes one pixel, the organic EL elements 100D are arranged in the number of pixels, for example, horizontal × vertical = 1280 × 1024, 640 × 480. . Then, in the image forming unit 10D, each organic EL element 100D causes each organic light emitting layer 102D to emit light based on a predetermined video signal, condenses them with a condenser lens (not shown), and enters the magnifying optical unit 5. .
Thus, by using an organic EL panel as the image forming unit 10D, it is possible to further reduce the size and power consumption of the spatial light modulation device (virtual image display device).
Also, the tenth embodiment can provide the same effects as those of the first embodiment described above.

The virtual image display device and the optical element of the present invention have been described based on the illustrated embodiment, but the present invention is not limited to this. For example, in the virtual image display device and the optical element of the present invention, the configuration of each part can be replaced with any configuration having the same function, and any other configuration can be added.
Further, the present invention may be a combination of any two or more configurations (features) of the above embodiments.

In the above-described embodiment, the case of forming the right-eye and left-eye virtual images has been described as an example. However, the configuration may be such that either the right-eye or left-eye virtual image is formed. Good.
In the above-described embodiment, the case where the present invention is applied to the eyeglass-type and headset-type head-mounted virtual image display devices has been described as an example. However, the present invention is not limited to this, for example, a helmet-type The present invention can also be applied to a head-mounted virtual image display device and a pseudo window that is not mounted on the head.

DESCRIPTION OF SYMBOLS 1 ... Virtual image display apparatus 1A ... Virtual image display apparatus 1B ... Virtual image display apparatus 1C ... Virtual image display apparatus 1D ... Virtual image display apparatus 1E ... Virtual image display apparatus 2 ... Frame 3 ... Signal generation part 4 ... Scanning light emission part 5 ... Magnification optical part 5A Magnifying optical unit 5B Magnifying optical unit 5C Magnifying optical unit 5D Magnifying optical unit 5E Magnifying optical unit 7 Optical fiber 10 Image forming unit 10A Image forming unit 10B Image forming unit 10C Image forming unit 10D Image Forming part 11 ... Movable mirror part 12a ... Shaft part 12b ... Shaft part 13 ... Frame body part 14a ... Shaft part 14b ... Shaft part 14c ... Shaft part 15 ... Supporting part 16 ... Permanent magnet 17 ... Coil 18 ... Signal superposition part 21 ... Lens unit 22 ... Temple unit 31 ... Signal light generation unit 32 ... Drive signal generation unit 33 ... Control unit 34 ... Lens 42 ... Optical scanning unit 43 ... Lens 51 1st light guide plate 51E ... 1st board | plate material 52 ... 2nd light guide plate 52E ... 2nd board | plate material 53 ... Mirror part 53E ... 1st member 54 ... Hologram 54E ... 2nd member 55E ... Mirror part 100D ... Organic EL element 101D ... Anode layer 102D ... Organic light emitting layer 103D ... Cathode layer 104D ... Glass substrate 111 ... Base 112 ... Spacer 113 ... Light reflector 114 ... Light reflector 115 ... Hard layer 200 ... Partially transmissive reflective surface 200A ... Part 200B ... Part 300 ... High Transmission surface 311B ... Light source 311G ... Light source 311R ... Light source 312B ... Drive circuit 312G ... Drive circuit 312R ... Drive circuit 313 ... Photosynthesis unit 313a ... Dichroic mirror 313b ... Dichroic mirror 321 ... Drive circuit 322 ... Drive circuit 400 ... High transmission surface 410 ... Illumination optical system 41 DESCRIPTION OF SYMBOLS 1 ... Light source 412 ... Reflector 413 ... 1st lens array 414 ... 2nd lens array 415 ... Polarization conversion element 416 ... Superimposing lens 420 ... Color separation optical system 421 ... B light reflection dichroic mirror 422 ... RG light reflection dichroic mirror 423 ... G light reflecting dichroic mirror 424 ... reflecting mirror 425 ... reflecting mirror 430R ... collimating lens 430G ... collimating lens 430B ... collimating lens 440R ... spatial light modulation device 440G ... spatial light modulation device 440B ... spatial light modulation device 450 ... cross Dichroic prism 450R ... incident surface 450G ... incident surface 450B ... incident surface 451 ... dielectric multilayer film 452 ... dielectric multilayer film 460 ... lens group 462 ... reflecting mirror 463 ... reflecting mirror 470 ... polarization rotator 500 ... part 500B ... part 500D ... part 501 ... end face 511 ... first main face 511A ... part 511B ... part 511E ... main face 512 ... second main face 513 ... side face 514 ... side face 515 ... end face 516 ... end face 520A ... part 520B: portion 521 ... first main surface 521E ... main surface 522 ... second main surface 523 ... side surface 524 ... side surface 525 ... end surface 526 ... end surface 531 ... upper surface 531E ... surface 541 ... surface 541E ... surface 620 ... light source device 621 ... Ultra-high pressure mercury lamp 622 ... Reflector 630 ... Uniform illumination optical system 631 ... Rod integrator 632 ... Color wheel 632a ... Filter surface 633 ... Relay lens group 634 ... Reflection mirror 640 ... Light modulation device 641 ... Substrate 642 ... Light modulation element 650 ... Lens group 651 ... Collection Optical lens 710 ... Light source unit 711B ... Laser light source 711G ... Laser light source 711R ... Laser light source 712R ... Collimator lens 713B ... Dichroic mirror 713G ... Dichroic mirror 713R ... Dichroic mirror 730 ... PBS prism 740 ... Reflective type liquid crystal panel 750 ... Lens group D1 ... separation distance D2 ... separation distance L ... light L1 ... light L2 ... light L3 ... light L4 ... light Lx ... light S1 ... space S2 ... space T1 ... period T2 ... period V1 ... first drive signal V2 ... second drive Signal f1 ... resonance frequency θ ... tilt angle θ1 ... tilt angle θ2 ... tilt angle

Claims (13)

An image forming unit that generates modulated image light based on the image signal and emits the image light;
The image light emitted from the image forming unit is incident, and an expansion optical unit that expands the image light in two dimensions, and
The magnifying optical part includes a light incident part on which the image light is incident,
A first reflecting surface provided to be inclined with respect to an incident direction in which the image light is incident on the light incident portion; and provided in parallel with the first reflecting surface to reflect a part of the image light; A first light guide having a second reflecting surface that transmits part of the image light;
A second light guide part for guiding the image light transmitted through the second reflecting surface;
A light extraction unit that is provided in the second light guide unit and extracts the image light guided through the second light guide unit to the outside of the second light guide unit;
The first light guide unit multi-reflects the image light between the first reflection surface and the second reflection surface, and transmits the image light transmitted through the second reflection surface to the second light guide unit. A virtual image display device characterized by being made incident on.   2. The virtual image display device according to claim 1, wherein the transmittance of the second reflecting surface has a portion that increases as the distance from the light incident portion increases.   The virtual image display device according to claim 1, wherein an inclination angle of the first reflecting surface and the second reflecting surface is 20 to 70 ° with respect to the incident direction.   The second light guide unit includes a third reflection surface and a fourth reflection surface that are provided to face each other, and multiple-reflects the image light between the third reflection surface and the fourth reflection surface. Item 4. The virtual image display device according to any one of Items 1 to 3. The second light guide has a plate material,
5. The virtual image display device according to claim 4, wherein one main surface of the pair of main surfaces of the plate member functions as the third reflecting surface, and the other main surface functions as the fourth reflecting surface.   The virtual image display device according to claim 4, wherein the light extraction unit includes a hologram provided on one of the third reflection surface and the fourth reflection surface. The second light guide unit includes a first plate member and a second plate member provided to face each other,
The main surface of the first plate member on the second plate member side functions as the third reflection surface, and the main surface of the second plate member on the first plate member side functions as the fourth reflection surface. Virtual image display device.   The virtual image display device according to claim 7, wherein one of the first plate member and the second plate member is made of a light transmissive material. The image light emitted from the image forming unit is incident, and includes a mirror unit that reflects the image light,
9. The virtual image display device according to claim 1, wherein the image light is incident on the first light guide unit after being reflected by the mirror unit. 10.   The virtual image display device according to claim 1, wherein the image forming unit includes a light source that emits light and an optical scanner that scans the light emitted from the light source.   The virtual image display device according to claim 1, wherein the image forming unit includes a light source and a spatial light modulation device that modulates light emitted from the light source based on the video signal.   The virtual image display device according to claim 1, wherein the image forming unit includes an organic EL panel. A light incident portion on which image light is incident;
A first reflecting surface provided to be inclined with respect to an incident direction in which the image light is incident on the light incident portion; and provided in parallel with the first reflecting surface to reflect a part of the image light; A first light guide having a second reflecting surface that transmits part of the image light;
A second light guide part for guiding the image light transmitted through the second reflecting surface;
A light extraction unit that is provided in the second light guide unit and extracts the image light guided through the second light guide unit to the outside of the second light guide unit;
The first light guide unit multi-reflects the image light between the first reflection surface and the second reflection surface, and transmits the image light transmitted through the second reflection surface to the second light guide unit. An optical element that is made incident on the optical element.

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