JP2002098928A - Video display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a video display device which has a display for displaying videos and an eyepiece optical system, is used in front of the face, facilitates observation of videos, regardless of the positional relation between the eyepiece optical system and the user's eyes and can provide the bright images. SOLUTION: The eyepiece optical system is composed of a hologram element and is so set that the hologram element diffracts the light from the display in different directions, by which the eyepiece optical system is provided with plural exit pupils. The exit pupils are set to the extent which is slightly larger than the human pupils and are lined up in the vertical direction or lateral direction or in both directions.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a personal image display device used in front of a face and providing a virtual image of an image displayed on a display unit by an eyepiece optical system.

[0002]

2. Description of the Related Art In recent years, an image display apparatus which is used in front of a face and guides light of an image displayed on a display unit to an eye by an eyepiece optical system to provide a virtual image of the image has been provided for an individual (one person). It has been proposed as a means.

[0003] For example, Japanese Patent Application Laid-Open No. 11-64781 discloses a spectacle-type configuration in which a display unit is arranged around a spectacle lens and a hologram element serving as an eyepiece optical system is attached to the surface of the spectacle lens. An image display device is disclosed. Light from the outside transmitted through the spectacle lens and light from the display unit reflected by the hologram element are guided to the user's eyes, and the user observes an enlarged virtual image of an image overlapping with a part of the image together with the image of the outside. be able to. Since the display unit is located around the visual field, light from the outside is hard to be blocked by the housing of the display unit, and the outside can be observed widely.

Japanese Patent Application Laid-Open No. 6-51239 discloses that
An image display device having a plurality of display units in a goggle type is disclosed. A hologram element is used as the eyepiece optical system, and light from each display unit is reflected on the same part or a different part of the hologram element and guided to the eye. Since the light from the outside world is not guided to the eyes, the outside world cannot be observed. However, the provision of the plurality of display units enables observation of a wide-field, high-definition image.

[0005]

However, in the conventional video display device, the exit pupil of the eyepiece optical system is small, so that it is difficult to observe an image depending on the positional relationship between the eyepiece optical system and the eyes of the user. There is. That is, since the light beam diameter from each point of the image is small, the pupil of the user is likely to deviate from the light beam, and a part of the observed image tends to be missing.
In particular, when providing a wide-field image, the amount of movement of the pupil increases, and this problem becomes significant. If the exit pupil of the eyepiece optical system is enlarged, the observation of an image becomes easy. However, if the exit pupil is enlarged, the optical system becomes large, the device becomes large, and the optical aberration increases.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and it is possible to provide a clear and easy-to-view image regardless of the positional relationship between the eyepiece optical system and the user's eye. It is an object of the present invention to realize a compact and lightweight video display device.

[0007]

In order to achieve the above object, according to the present invention, a display unit for displaying an image and an eyepiece optical system are provided, and the eyepiece optical system is used in a state in which the eyepiece optical system is located in front of an eye. In an image display device that guides light from a display unit to an eye by an eyepiece optical system and provides a virtual image of an image displayed by the display unit, the eyepiece optical system has a plurality of exit pupils.

In this image display device, if the user's pupil enters any one of the plurality of exit pupils, light from the display unit enters the eye, and the position of the eye with respect to the eyepiece optical system is constant. You can observe the video without it. Also,
Since it is not necessary to increase the size of each exit pupil, an optical aberration hardly occurs, and the apparatus is small and lightweight.

Here, the traveling direction of light from the display unit passing through the exit pupil may be different for each exit pupil. Even when the pupil straddles two exit pupils and observes two images (virtual images), there is a difference in the position of both images in the field of view due to the difference in the traveling direction of light, so that the images are difficult to see overlapping. Can be avoided.

The exit pupils may be separated from each other in a direction perpendicular to the direction connecting the eye and the eyepiece optical system.
It is easier to avoid the pupil from straddling the two exit pupils. By setting the interval between the exit pupils to be equal to or larger than the diameter of the pupil, the pupil does not straddle the two exit pupils, and it is possible to reliably avoid overlapping of images.

The light from the display unit may include light having different wavelengths, and the light having different wavelengths may be separated from each other and pass through different exit pupils. Since the colors of the images differ for each exit pupil, even when two images overlap, both images can be easily identified.

Light from the display section may include light having different wavelengths, and any light having different wavelengths may pass through all exit pupils. In this way, a color image can be observed at any exit pupil, depending on the setting of the relative intensity of light having different wavelengths.

The eyepiece optical system may be constituted by a hologram element. The hologram element can be easily set to guide light incident on the same part from the same direction to a plurality of directions,
A small eyepiece optical system can be provided while having a plurality of exit pupils. In addition, since both reflected light and transmitted light can be guided to the eyes, not only images but also the outside world can be observed.

[0014] The above-mentioned image display device can be configured to have a transparent plate-shaped member that holds the eyepiece optical system and faces the eye during use. Light from the outside passing through the plate-like member also enters the user's eyes, so that the outside can be observed together with the image. If the eyepiece optical system is a hologram element, the image does not obstruct the outside world.

It is preferable that the plate-like member reflects the light from the display portion, which enters from the end portion, internally and guides the light to the eyepiece optical system. By making the plate-shaped member large and thin, the display unit can be positioned outside the field of view of the user, and a wide field of view with respect to the outside world can be secured while suppressing the weight of the device.

The plate member may have optical power. The diopter can be adjusted by the power of the plate-shaped member, so that even a user with reduced visual acuity can clearly observe the outside world without using other correction means.

A mounting member for mounting on a user's head may be provided. This eliminates the need to hold it by hand, making the device easy to use.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the video display device of the present invention will be described with reference to the drawings. FIG. 1 shows the appearance of the video display device 1 according to the first embodiment. The image display device 1 includes a display unit 11R that displays an image, and a display unit 11R.
Hologram element 12R that reflects light from the light source, a pair of transparent and plate-shaped transparent plates 13L and 13R, and a transparent plate 13
Connecting part 15 for connecting L and 13R, a pair of temples 16
L, 16R, and a pair of nose pads 17L, 17R.

The image display device 1 has a shape almost like spectacles as a whole and, like the spectacles, a transparent plate 13.
L and 13R are mounted on the head such that they face the left and right eyes, respectively. The temples 16L and 16R are attached to the ends of the transparent plates 13L and 13R, respectively.
7L and 17R are attached to the connecting portion 15. The temples 16L and 16R and the nose pads 17L and 17R are mounting members supported by the head and supporting the transparent plates 13L and 13R.

The display section 11R is fixed to the upper end of the transparent plate 13R. At the time of wearing, the display unit 11R is located outside the field of view of the user and does not obstruct the field of view. Display unit 11
The operation of R is controlled by a control device (not shown) connected via a cable 18. Transparent plate 13L, 1
3R has an outer shape close to an elliptical shape like a lens of ordinary spectacles, and has a size corresponding to substantially the entire field of view.
The transparent plates 13L and 13R have front surfaces (surfaces far from eyes) and rear surfaces (surfaces close to eyes) that are parallel planes, and do not have optical power.

The hologram element 12R is in the shape of a rectangular thin plate, and is provided near the center of the transparent plate 13R. The transparent plate 13R holds the hologram element 12R, and positions the hologram element 12R immediately before the right eye when mounted. The hologram element 12R is inclined with respect to the surface of the transparent plate 13R, and the lower end thereof is closer to the face than the upper end when mounted. Light from the display unit 11R is reflected by the hologram element 12R and enters the right eye. Light from the outside passes through the transparent plate 13R and enters the right eye.

The hologram element 12R is set so that its reflected light represents an enlarged virtual image of the image on the display unit 11R, and functions as an eyepiece optical system. The provided virtual image is about ten times or more the size of the real image of the display unit 11R, and is located at a distance of one to several meters in front of the eye. The hologram element 12R is set so as to transmit light from the outside world. Therefore, the virtual image of the image is observed overlapping with the center of the outside world image.

FIG. 2 shows a vertical cross section of the display section 11R and the transparent plate 13R, and FIG. 3 shows a horizontal cross section of the transparent plate 13R. The display unit 11R includes a transmission type liquid crystal display (LCD) 11a,
It comprises a light emitting diode (LED) 11b, a lens 11c, and a housing 11d for housing these. LED 11b
Emits light of a predetermined wavelength for illuminating the LCD 11a, and the lens 11c transmits light from the LED 11b to the LCD 1a.
1a is uniformly guided over the entire surface. The LCD 11a displays an image and modulates the light provided from the LED 11b via the lens 11c.

The transparent plate 13R is composed of two pieces 13a, 13b.
Are joined together. The refractive indices of the pieces 13a and 13b are equal, and the surfaces of both are continuous. Element 1
The joining surface of 3a and 13b is inclined with respect to the surface, and the hologram element 12R is provided on this joining surface. The upper end of the element 13a has a wedge shape that bulges toward the front as it approaches the edge, and the housing 11d is fixed so as to sandwich the wedge-shaped portion from front and rear.

The light modulated by the LCD 11a enters the transparent plate 13R from the upper end surface of the element 13a and reaches the rear surface. The LED 11b, the lens 11c, and the LCD 11a
The light is incident on the rear surface of the transparent plate 13 so as to exceed the critical angle, and the light that reaches the rear surface is totally reflected. The light reflected on the rear surface is also totally reflected on the front surface, and is repeatedly reflected several times in the transparent plate 13R to form the hologram element 1.
It is incident on 2R. By guiding light to the hologram element 12R by multiple reflections in this manner, the transparent plate 13R can be made large and thin. The thickness of the transparent plate 13R is 3
mm or less.

The hologram element 12R converts the light incident on each part into a substantially horizontal direction (a direction substantially perpendicular to the rear surface of the transparent plate 13), a direction slightly above the horizontal direction, and a little more than the horizontal direction. Diffracted in three obliquely downward directions, and three exit pupils 14C, 14U, and 14D in a vertical (up and down) direction.
Is set to form The intensity of the light diffracted in these three directions is 1/3 of the intensity of the incident light. Each of the exit pupils 14C, 14U, and 14D has a diameter of 3 mm, which is slightly larger than the diameter (about 2 mm) of the pupil of the person in the open state. The lower end of the exit pupil 14U and the upper end of the exit pupil 14D are close to the upper end and the lower end of the exit pupil 14C, respectively.

Therefore, the image display device 1 has an exit pupil in a range of 9 mm in the vertical direction and 3 mm in the horizontal direction, and the user can observe an image (enlarged virtual image) as long as the pupil is within this wide range. Can be. In addition, since the individual exit pupils 14C, 14U, and 14D are not so large, optical aberration hardly occurs, and the observed image is clear.

When the pupil is inside any one of the exit pupils 14C, 14U, 14D, only one image is observed, and the pupil straddles the two exit pupils 14C, 14U or 14C, 14D. In the state, two images are observed. The image observed through the exit pupil 14U is located below the image observed through the exit pupil 14C, and the image observed through the exit pupil 14D is
It is located above the image observed through the exit pupil 14C.

In FIGS. 2 and 3, reference numeral A denotes a line of sight when the user is looking straight ahead, and hereinafter, this line is referred to as a normal line of sight. Exit pupil 1 based on the standard line of sight A
The angles of the upper and lower ends of the field of view of 4C (the range of the image observed through the exit pupil 14C) are CU and CD, and the angles of the upper and lower ends of the field of view of the exit pupil 14U are UU, UD, and the field of view of the exit pupil 14D. When the angles of the upper end and the lower end of are represented by DU and DD, each angle is CU <0 (CU ≒ 0), CD <0,
UU <0, UD <0, DU> 0, DD> 0 (DD ≒ 0), UU
<CD and CU−CD = UU−UD = DU−DD.

Here, CD <0 and UU <0, but UU
Since <CD, that is, UU.> CD., Even when the pupil straddles the exit pupils 14C and 14U and two images are observed, no part of those images overlaps. Since DD> CU, the pupil is located at the exit pupil 14.
When two images are viewed over C and 14D, no portion of those images will overlap.
The horizontal visual fields of the exit pupils 14U and 14D are shown in FIG.
Is the same as the field of view of the exit pupil 14C shown in FIG.

FIG. 4 shows the positional relationship of the images VC, VU, and VD observed through the exit pupils 14C, 14U, and 14D within the entire field of view of the user. With the above-described settings, the user can view the images VC and VU substantially in front through the central exit pupil 14C, downward through the upper exit pupil 14U, and upward through the lower exit pupil 14D. , VD. It is to be noted that a situation in which an image is observed simultaneously through the upper and lower exit pupils 14U and 14D does not occur.
The position of the user's eyes in the vertical direction is different between when observing the video VD via 4D.

The LED 11b of the display unit 11R is 550 nm
Emits light of the wavelength Light wavelength and hologram element 12R
FIG. 5 shows the relationship between the reflectance and the transmittance of. The hologram element 12R is set to diffract light in the wavelength range of 550 ± 10 nm, diffracts and reflects only light in this wavelength range, and transmits almost all light outside this wavelength range.

Therefore, all the light from the display unit 11R is guided to the exit pupils 14C, 14U, and 14D, so that a bright image can be observed, and the outside world can be naturally observed with little coloration.

Although the colors of the images observed through the exit pupils 14C, 14U and 14D are all the same, even when two images are observed at the same time, since the images do not overlap, each image is difficult to see. This does not occur. In addition, since the intensities of the light diffracted in the three directions by the hologram element 12R are equal, the brightness of the image observed through the exit pupils 14C, 14U, and 14D is the same, and the sense of incongruity due to the difference in brightness does not occur. .

In the present embodiment, the image is provided to the right eye of the user, but the image may be provided to the left eye. In addition, as described later, a configuration in which an image is provided to both eyes may be adopted.

Hereinafter, a video display device according to another embodiment will be described. However, components having the same or similar functions as those of the video display device 1 are denoted by the same reference numerals, and redundant description will be omitted.

The image display apparatus 2 of the second embodiment changes the diffraction characteristics of the hologram element 12R, which is an eyepiece optical system, and uses the LED 11b of the display section 11R as a red (R) light, a green (G) light, It is provided with three types that respectively emit blue (B) light. The other configuration is the image display device 1.
The image display device 2 has the appearance shown in FIG.

The display section 11R of the image display device 2 and the transparent plate 1
FIG. 6 shows a vertical cross section of 3R, and FIG. 7 shows a horizontal cross section of transparent plate 13R. In the image display device 2, the hologram element 1
The 2R diffracts light from the display unit 11R incident on each part in a direction substantially along the normal line of sight A, a direction slightly diagonally to the left of the normal line of sight A, and a direction slightly diagonally right of the normal line of sight A. , Three exit pupils 14C, 14L in the horizontal (left / right) direction,
14R.

The LED 11b emits light having wavelengths of 630 nm, 520 nm, and 465 nm as R light, G light, and B light. The hologram element 12R diffracts 1/3 of each of the R light, the G light, and the B light in three directions. Therefore, each of the exit pupils 14C, 14L, and 14R has 3
Color light is guided, and there is no difference in the intensity of each color light between the exit pupils.

The image display device 2 provides a color image. The provision of a color image is performed by controlling the display of the LCD 11a and the emission of the LED 11b in synchronization with each other so that the color components of the image displayed by the LCD 11a correspond to the color light emitted by the LED 11b. For example, an R component, a G component, and a B component of a video are displayed in order on the LCD 11a, and in synchronization with the display, the LED 11b emits R light, G light, and B light.

The hologram element 12R is manufactured by using one photosensitive material and sequentially forming interference fringes with the above three wavelengths of light. The interference fringes formed at each stage are formed so as to diffract light with equal intensity in three directions. As a result, the images viewed through any of the exit pupils 14C, 14L, and 14R have the same brightness and color. The relationship between the light wavelength and the reflectance and transmittance of the hologram element 12R is the same as that shown in FIG. 5 except that there are three peaks in reflectance corresponding to the three wavelengths.

The exit pupils 14C, 14L, 14R have a diameter of 3 mm, similar to the exit pupils 14C, 14U, 14D of the image display device 1, and are close to each other. Therefore, the image display device 2 is 3 mm vertically and 9 m horizontally.
The user has an exit pupil in the range of m, and the user can observe an image as long as the pupil is within this wide range.

The angle of the left end and the right end of the field of view of the exit pupil 14C is represented by C, with the left being positive with respect to the normal line of sight A.
L, CR, when the angles of the left and right ends of the field of view of the exit pupil 14L are represented by LL, LR, and the angles of the left and right ends of the field of view of the exit pupil 14R are RL, RD, each angle is CL> 0.
CR <0, LL> 0, LR <0, RL> 0, RR <0, CL
・ = ・ CR ・ 、 ・ LL ・ = ・ RR ・ 、 ・ LR ・ ＝ ・ RL ・ 、
In addition, the relationship is determined so that CL-CR = LL-LR = RL-RR, and the field of view is symmetric.

However, since LL> CR and RR <CL,
The field of view of the exit pupil 14C and the field of view of the exit pupil 14L partially overlap, and the field of view of the exit pupil 14C and the field of view of the exit pupil 14R partially overlap. Therefore, if the pupil straddles the two exit pupils, the two observed images will also overlap. However, since the image is a color image, the colors of the left and right portions in the image often differ, and it is not difficult to identify the image.

The image display device 3 according to the third embodiment has the first
This is a modification of the diffraction characteristic of the hologram element 12R of the image display device 1 according to the embodiment. FIG. 8 shows a vertical cross section of the display unit 11R and the transparent plate 13R, and FIG. 9 shows a horizontal cross section of the transparent plate 13R.

In the image display device 3, the hologram element 12
R represents light from the display unit incident on each part in a direction substantially along the line of sight A, a direction obliquely above the line of sight A, a direction obliquely below the line of sight A, and substantially parallel to the line of sight A. Direction to the left,
It is set so as to be diffracted substantially parallel to the standard line of sight A and rightward to form five exit pupils 14C, 14U, 14D, 14L and 14R. Specifically, the hologram element 12R is set to diffract at different angles in the vertical direction, and to diffract in the same direction in the center, left half, and right half in the horizontal direction.

Each exit pupil has a size of 3 mm in diameter as described above. All exit pupils are separated from each other in a direction perpendicular to the normal line of sight A, and the exit pupil 14C and the exit pupil 14
The distance W between U, 14D, 14L and 14R is 2m
m, about the diameter of a human pupil. Therefore, the image display device 3 has an exit pupil in a wide range of 13 mm vertically and 13 mm horizontally. The user can observe the image as long as any of the exit pupils have a pupil.

Since all the exit pupils are separated from each other by about the diameter of the pupil, the pupil does not straddle the two exit pupils. That is, the user observes only one image at a time.

Although the number of exit pupils is five in this case, the number of exit pupils is 9 above and below the exit pupils 14L and 14R.
It may have one exit pupil, or may have more exit pupils. Since the hologram element can freely set diffraction characteristics, it is easy to manufacture such an eyepiece optical system.

The video display device 4 according to the fourth embodiment has a
In addition to changing the diffraction characteristics of the hologram element 12R of the image display device 1 according to the embodiment, the LED 1 of the display unit 11R
1b is provided with three types that respectively emit R light, G light, and B light. The LED 11b is used as the R light, the G light, and the B light as in the image display device 2 according to the second embodiment.
It emits light with wavelengths of 30 nm, 520 nm and 465 nm.

FIG. 10 shows a vertical cross section of the display section 11R and the transparent plate 13R, and FIG. 11 shows a horizontal cross section of the transparent plate 13R. The hologram element 12R diffracts light from the display unit 11R in five directions, and outputs the five exit pupils 14C, 14U, 14
D, 14L and 14R are formed. The size of each exit pupil is 3
mm.

Three exit pupils 14C in the vertical (up / down) direction,
The positional relationship between 14U and 14D is exactly the same as that of the image display device 1 of the first embodiment, and their exit pupils are close to each other. Three exit pupils 14C, 1 in the horizontal (left / right) direction
The positional relationship between 4L and 14R is similar to that of the video display device 3, but the separation distance is small. Therefore, the pupil of the user may straddle two exit pupils in the up-down direction, two exit pupils in the left-right direction, and three exit pupils (14C and 14C, for example).
U, 14L).

The exit pupils 14C, 14U, 14D, 14L,
Only one of the R light, the G light, and the B light from the display unit 11R is guided to 14R. The color light guided to the adjacent exit pupil is different.
G light, exit pupils 14L, 1
B light is guided to 4R. Therefore, even when the user's pupil straddles two or three exit pupils and two or three images are observed, the images are easy to identify because the colors are different.

The hologram element 12R is manufactured by laminating three photosensitive materials in which interference fringes are individually formed using light of the above-mentioned wavelength. The interference fringes of each photosensitive material are formed so as to cause diffraction only in a predetermined direction, and to diffract only a wavelength range of light (for example, 630 nm) ± 10 nm of light used for photosensitive. Therefore, the LED 11b
Emits R light, G light, and B light at the same time.
The color light guided to each of the 4U, 14D, 14L, and 14R is not mixed with another color light, and there is no light loss.

Although the wavelength of the light emitted from the LED 11b is set to be largely different here, it is not necessary to make the wavelength greatly different from the viewpoint of light use efficiency. Wavelength 50
0, 520, 540 nm, 500 ± 10, 520 ±
The hologram element 12R may be manufactured by laminating three photosensitive materials having interference fringes formed so as to diffract light in a wavelength range of 10, 540 ± 10 nm. However, in that case, the difference in the color of the image when the pupil straddles two or more exit pupils becomes small.

The video display device 5 according to the fifth embodiment has a
The hologram element 12R of the image display device 2 according to the embodiment has a different diffraction characteristic. FIG. 12 shows a horizontal cross section of the transparent plate 13R of the video display device 5. The difference from the image display device 2 is that the hologram element 12R diffracts the light from the display unit 11R at different portions in the horizontal (left and right) directions, and the three exit pupils 14C, 14L, and 14R are the turning points of the user's eye. The point is that they are arranged on an arc centered on P.

When the angles at the left end and right end of the visual field of the exit pupils 14C, 14L, 14R are expressed as described above, the angles are CL> 0, CR <0, LL> 0, LR> 0, RL <0,
RR <0, .CL. =. CR., .LL. =. RR .., LR
・ = ・ RL ・, LR> CL, RL <CR, and CL−CR = LL
-LR = RL-RR.
Since LR> CL and RL <CR, the exit pupils 14L and 14R
Does not overlap with the image observed through the exit pupil 14C.

Further, since the exit pupils 14C, 14L, 14R are on an arc centered on the rotation point P of the eye, even if the user rotates the eye in the left-right direction, the pupil enters one of the exit pupils. Moreover, the direction of the line of sight matches the direction of the visual field. Therefore, it is possible to observe the video very easily.

The video display device 6 according to the sixth embodiment will be described. The image display device 6 has the same appearance as the image display devices 1 to 5 of the above embodiments, but includes a mirror 19R having a free-form surface as the eyepiece optical system on the transparent plate 13R instead of the hologram element 12R. It is. Display unit 11
FIG. 13 shows a vertical cross section of R and the transparent plate 13R.
FIG. 14 shows a horizontal section of the 3R. The mirror 19R has three portions 19a, 19b, 19 arranged in a horizontal (left / right) direction.
c, and each part is concave with respect to the light from the display unit 11R.

The mirror 19R reflects the light from the display unit 11R at the central part 19a in the direction along the line of sight A, and at the left and right parts 19b and 19c, reflects slightly inward. The exit pupils 14C, 14L, 14R are formed. The exit pupils 14C, 14L, and 14R are connected to the image display device 5
Similarly to the above, they are arranged on an arc centered on the rotation point of the user's eye.

The mirror 19R may be a total reflection mirror or a half mirror. With a total reflection mirror, a bright image can be provided, and with a half mirror, a portion of the outside world that overlaps the image can be observed.

The images observed through the exit pupils 14C, 14L, 14R may be all the same color as in the image display device 1, or may be different colors as in the image display device 4. Further, a color image can be displayed as in the image display device 2.

FIG. 15 shows the appearance of the video display device 7 of the seventh embodiment. This image display device 7 is also provided with a hologram element 12L on a transparent plate 13L facing the left eye, and additionally with a display unit 11L and attached to the upper end of the transparent plate 13L to provide images to both eyes. , Transparent plate 13
The diopter is adjusted by giving optical power to L and 13R.

Hologram element 12L and display section 11L
Are the same as those of the hologram element 12R and the display section 11R. The display units 11L and 11R and the hologram elements 12L and 12R are the same as those of the image display devices 1 to 5 of the first to fifth embodiments, and three or five hologram elements 12L and 12R as the eyepiece optical system are provided. It has two exit pupils.

In the image display device 7, since there are a plurality of exit pupils of the eyepiece optical system, observation of an image is easy, and
By displaying images having parallax by L and 11R, stereoscopic images can be observed. Moreover, the transparent plate 13L, 1
With the diopter adjustment function of the 3R, even a person whose visual acuity such as myopia or hyperopia has deteriorated can observe the external world clearly without using other visual acuity correcting means.

In order to provide power, the transparent plate 1
Either the front surface or the rear surface of the 3L, 13R may be a curved surface, and both surfaces may be curved surfaces. Transparent plate 13L, 1
When the rear surface of the 3R is a curved surface, the hologram element 12L,
The diffraction characteristic of 12R is set in consideration of the curvature of the rear surface.

FIG. 16 shows a main part of a video display device 8 according to the eighth embodiment. The image display device 8 transforms the image display device 7 to display the display units 11L and 11R on the temples 16L and 16R.
The hologram elements 12L and 12R, which are eyepiece optical systems, are attached to the rear surfaces of the transparent plates 13L and 13R instead of being provided inside the transparent plates 13L and 13R. The transparent plates 13L and 13R are each formed of a single element.

Light from the display units 11L and 11R passes directly through the air and directly enters the hologram elements 12L and 12R. The hologram elements 12L and 12R diffract light from the display unit in three directions, and three exit pupils 14C, 14L,
Form 14R. The exit pupils 14C, 14L, 14R
They are 1 mm in diameter and 3 mm apart, and are arranged on an arc centered on the turning point of the user's eye, similar to the image display device 5.

The image display device 8 having this configuration is very easy to manufacture. By simply adding the hologram elements 12L and 12R and the display units 11L and 11R to the glasses that the user uses everyday, the image display device 8 can be obtained.

A video display device 9 according to the ninth embodiment will be described. The image display device 9 is incorporated in a mobile phone, and provides received information and transmitted information to a user as an image. FIG. 17 shows the appearance of a mobile phone 20 incorporating the video display device 9. Mobile phone 20
Is composed of a main body 20a and a lid 20b, and can be folded so that the lid 20b overlaps the main body 20a when not in use.

The main unit 20a mainly controls the function of the telephone, incorporates a signal processing circuit, a plurality of keys 21 for inputting a telephone number and the like, a liquid crystal display 22 for displaying the inputted telephone number, Antenna 2 for transmitting and receiving radio waves
3. It is provided with a speaker 24 for outputting the received sound. The cover 20b is provided with a microphone 2 for voice input.
5 and a built-in video display device 9. A window 20c is provided on the inner surface of the lid 20b, and a window facing the window 20c is also provided on the outer surface.

FIG. 18 shows a cross section of the image display device 9 taken along line XX ′ of FIG. The image display device 9 includes a display unit 11R,
It comprises a hologram element 12R and a transparent plate 13R.
The display unit 11R has a configuration similar to that of the video display device 2 according to the second embodiment, except that a reflector 1 is used instead of a lens.
1c ', which allows the light from the LED 11b to be
It leads to D11a. The transparent plate 13R also has a configuration similar to that of the image display device 2, but a wedge-shaped portion for fixing the display unit 11R protrudes to the rear side. The hologram element 12R has exactly the same configuration as that of the image display device 2, and includes three exit pupils 14C, 14L, and 14 shown in FIG.
R (FIG. 18 shows only the central exit pupil 14C).

In the image display device 9, the transparent plate 13R is
It is arrange | positioned inside the cover part 20b so that it may face c. The user holds the mobile phone 20 by hand so that the transparent plate 13R and the window 20c are located in front of the eyes, and the speaker 24 of the main body 20a is located near the ear, so that the user can make a call. You can observe an image of the outside world and an image that overlaps it. Even when used in this state, the voice uttered by the user is detected by the microphone 25.

Since the image display device 9 incorporated in the mobile phone 20 is of a hand-held type, it is difficult to always keep the position with respect to the user's eyes constant. However, the hologram element 12R, which is an eyepiece optical system, has a plurality of exit pupils 14C and 14C.
Since the pupil has L and 14R, the pupil can easily enter any one of the exit pupils, and observation of an image is easy. Moreover, the transparent plate 13
Since it is possible to observe the outside world through the R and the hologram element 12R, it is safe for a user to observe a video using a mobile phone while walking.

[0075]

According to the image display apparatus of the present invention in which the eyepiece optical system has a plurality of exit pupils, it is possible to observe an image at each exit pupil, and the position of the user's eye with respect to the eyepiece optical system is restricted. Few. Therefore, it is not necessary to precisely determine the position of the device in front of the user's face. In addition, it is possible to observe all parts of a wide-field image at a time. Moreover,
Since it is not necessary to increase the size of each exit pupil, aberrations are less likely to occur, a clear image without blur can be provided, and the device is small and lightweight.

If the traveling direction of light from the display unit passing through the exit pupil is made different for each exit pupil, even when the user's pupil straddles two exit pupils and observes two images, both images are displayed. Can be prevented from overlapping. Therefore, it is not difficult to see.

Further, if the exit pupils are separated from each other in a direction perpendicular to the direction connecting the eye and the eyepiece optical system, it is possible to prevent the pupil from observing two images simultaneously across the two exit pupils. It becomes easier.

If the light from the display unit includes light having different wavelengths and light having different wavelengths is separated from each other and passes through different exit pupils, even when two images overlapped are to be observed, Images can be easily identified.

If the light from the display unit includes light having different wavelengths, and all the light having different wavelengths pass through all exit pupils, a color image can be observed at any exit pupil.

If the eyepiece optical system is constituted by a hologram element, a small eyepiece optical system can be obtained while having a plurality of exit pupils, and it is possible to observe not only images but also the outside world.

In a configuration in which the eyepiece optical system is held and a transparent plate-shaped member facing the eye when used is used, the outside world can be observed together with the image. If the eyepiece optical system is constituted by a hologram element, the outside world is not interrupted by the image.

When the plate-like member reflects the light from the display section which enters from the end thereof and guides it to the eyepiece optical system, the plate-like member is made large and thin so that the display section is out of the field of view of the user. The device can be positioned at a position that is light and does not hinder the observation of the outside world.

When the plate member is made to have optical power, even a user with reduced visual acuity can observe the outside world clearly without using other correcting means. In addition, in a configuration including a mounting member for mounting on a user's head, the device is easy to use.

[Brief description of the drawings]

FIG. 1 is a perspective view of a video display device according to a first embodiment.

FIG. 2 is a vertical sectional view of a display unit and a transparent plate of the video display device according to the first embodiment.

FIG. 3 is a horizontal sectional view of a transparent plate of the video display device according to the first embodiment.

FIG. 4 is a diagram showing a positional relationship of an image observed through an exit pupil of the image display device of the first embodiment in a whole field of view of a user.

FIG. 5 is a diagram showing the relationship between the reflectance and the transmittance of the hologram element of the image display device of the first embodiment and the wavelength of light.

FIG. 6 is a vertical sectional view of a display unit and a transparent plate of the video display device according to the second embodiment.

FIG. 7 is a horizontal sectional view of a transparent plate of the video display device according to the second embodiment.

FIG. 8 is a vertical sectional view of a display unit and a transparent plate of the video display device according to the third embodiment.

FIG. 9 is a horizontal sectional view of a transparent plate of the video display device according to the third embodiment.

FIG. 10 is a vertical sectional view of a display unit and a transparent plate of a video display device according to a fourth embodiment.

FIG. 11 is a horizontal sectional view of a transparent plate of the video display device according to the fourth embodiment.

FIG. 12 is a horizontal sectional view of a transparent plate of the video display device according to the fifth embodiment.

FIG. 13 is a vertical sectional view of a display unit and a transparent plate of a video display device according to a sixth embodiment.

FIG. 14 is a horizontal sectional view of a transparent plate of the video display device according to the sixth embodiment.

FIG. 15 is a perspective view of an image display device according to a seventh embodiment.

FIG. 16 is an exemplary plan view of a main part of a video display device according to an eighth embodiment;

FIG. 17 is a perspective view of a mobile phone incorporating the video display device according to the ninth embodiment.

FIG. 18 is a sectional view of an image display device according to a ninth embodiment.

[Explanation of symbols]

 1, 2, 3, 4, 5, 6, 7, 8, 9 Image display device 11L, 11R Display unit 11a Liquid crystal display 11b Light emitting diode 11c Lens 11c 'Reflector 11d Housing 12L, 12R Hologram element 13L, 13R Transparent plate 14C , 14U, 14D, 14L, 14R Exit pupil 15 Connecting portion 16L, 16R Temple 17L, 17R Nose pad, 18 Cable 19R Mirror 20 Cellular phone 20a Main unit 20b Cover 21 Input key 22 Liquid crystal display 23 Antenna 24 Speaker 25 Microphone

Claims (10)

[Claims] 1. An image display device comprising: a display unit for displaying an image; and an eyepiece optical system, wherein the eyepiece optical system is used in a state in front of an eye,
An image display device for guiding light from a display unit to an eye by an eyepiece optical system to provide a virtual image of an image displayed by the display unit, wherein the eyepiece optical system has a plurality of exit pupils. 2. The image display device according to claim 1, wherein the traveling direction of light from the display section passing through the exit pupil is different for each exit pupil. 3. The image display device according to claim 1, wherein the exit pupils are separated from each other in a direction perpendicular to a direction connecting the eye and the eyepiece optical system. 4. The display device according to claim 1, wherein light from the display unit includes light having different wavelengths, and the light having different wavelengths is separated from each other and passes through different exit pupils. 3. The video display device according to 1. 5. The light-emitting device according to claim 1, wherein light from the display unit includes light having different wavelengths, and any light having different wavelengths passes through all exit pupils. The image display device according to the above. 6. The image display device according to claim 1, wherein the eyepiece optical system comprises a hologram element. 7. The image display device according to claim 1, further comprising a transparent plate-shaped member that holds the eyepiece optical system and faces the eye during use. 8. The image display device according to claim 7, wherein the plate-like member internally reflects light from the display section incident from an end thereof and guides the light to the eyepiece optical system. 9. The image display device according to claim 7, wherein the plate member has optical power. 10. The video display device according to claim 1, further comprising a mounting member for mounting on a head of a user.