JP4273831B2 - Video display device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an image display apparatus that provides an image by an eyepiece optical system including a hologram.
[0002]
[Prior art]
An image display device that modulates light from a light source with a modulation element such as a liquid crystal display to produce image light, and guides the image light to an observer's eye by an eyepiece optical system using a hologram, has attracted attention as a small and lightweight image providing means. ing. Such a video display device is configured to be worn in front of the eye in the shape of glasses, for example, and can also provide a video superimposed on an image of the outside world. If a plurality of light sources that emit light of different wavelength bands are provided, a color image can be provided.
[0003]
In an image display device that provides an image via an eyepiece optical system, it is desirable to increase the exit pupil in order to provide an indelible image. By enlarging the exit pupil, observation is facilitated, and when providing images to both eyes, individual differences in eye width (interval between the left and right eyes) can be allowed.
[0004]
Several techniques for enlarging the exit pupil with a configuration using a hologram for the eyepiece optical system have been proposed. For example, in Japanese Patent Laid-Open No. 6-118234, a single hologram is divided into a plurality of element holograms and exposed, and an exit pupil is formed so that light beams from different regions do not overlap, thereby expanding the exit pupil. I am trying. However, in this method, since only light from a partial region of the hologram is incident on the pupil, the provided image becomes dark.
[0005]
In US Pat. No. 5,363,220, in a head-up display using a hologram as a combiner, the pupil is enlarged by making the diffraction efficiency of the hologram constant over a wide wavelength band. However, if diffraction occurs over a wide wavelength band, the transmittance of light from the outside becomes low, and the image of the outside becomes dark and difficult to observe.
[0006]
[Patent Document 1]
JP-A-6-118234 [Patent Document 2]
US Pat. No. 5,363,220
[Problems to be solved by the invention]
Since the hologram has a large wavelength selectivity and angle selectivity, the diffraction efficiency varies greatly depending on the wavelength of light and the incident angle. Therefore, in an image display apparatus that uses a hologram for an eyepiece optical system, the light flux at the exit pupil is particularly susceptible to the diffraction efficiency of the hologram, and the size of the exit pupil is not limited to the setting of the hologram, Depends on the angle of incidence on the hologram.
[0008]
However, as a method of enlarging the exit pupil, only the hologram itself is devised as described above, and the exit pupil is not enlarged by setting the image light. For this reason, even though the exit pupil can be enlarged, there are inconveniences that the provided image becomes dark and observation of the image of the outside world becomes difficult.
[0009]
The present invention has been made in view of such a current situation, and realizes an image display device using a hologram for an eyepiece optical system, which can provide a high-quality image with a large exit pupil. For the purpose.
[0010]
[Means for Solving the Problems]
To achieve the above object, provides a video display apparatus according to the first invention, raw Narute stage generates an image light including light of a different wavelength band, and the image represented by the image light from the generating means to the observer An image display device comprising an eyepiece optical system, wherein the eyepiece optical system includes a hologram, and the first light, the second light, and the third light having at least three different wavelength bands are converted into image light. A first wavelength range from 400 nm to 500 nm, a second wavelength range from 500 nm to 600 nm, and a third wavelength range from 600 nm to 700 nm. A wavelength range in which the first light and the second light are within the first to third wavelength ranges, and the wavelength range of the third light is within the same wavelength range. In a different wavelength range The exit pupil of the first light and the exit pupil of the second light are offset from each other and partially overlap, and the exit pupil of the third light is the exit pupil of the first light and the exit pupil of the second light. It is characterized by substantially matching the whole .
[0011]
In this video display device, the exit pupil as a whole is larger than the exit pupil of light in a single wavelength band, so the relative position between the observer's eye and the device capable of observing the video without exception The range expands. Therefore, the present invention is particularly suitable for a spectacle-like form in which the relative position between the observer's eyes and the apparatus is likely to vary. In addition, since the image light includes light of a plurality of wavelength bands, a bright image can be provided while having a large exit pupil. In this video display device, the video light includes light in at least two of a blue region (wavelength 400 to 500 nm), a green region (500 to 600 nm), and a red region (600 to 700 nm). The first and second lights belong to the same color region with different wavelength bands, and their exit pupils partially overlap to form a large exit pupil. The third light belongs to a color region different from that of the first and second lights, and its exit pupil substantially coincides with a large exit pupil formed by the exit pupils of the first and second lights. Therefore, it has a large exit pupil as a whole and can provide a color image, not monochrome, without color unevenness. In addition, in the configuration in which the generating unit modulates the light from the light source to obtain the image light, the light source having a particularly wide wavelength band is used as the third light source, and the light sources having the narrow wavelength band are the first and second light sources. By using as a light source, it is possible to provide a color image with a good color balance while fully utilizing the features of a light source having a wide wavelength band.
[0012]
Since the exit pupil and the exit pupil of the second light of the first light overlaps the part-form, it is possible to provide a bright image. Further, it is preferable that the wavelength band of all the light included in the video light be within the wavelength range of 100 nm in width. In this way, since the color difference between the individual lights is small, it is possible to suppress changes in the color of the observed image depending on the relative position between the observer's eyes and the apparatus. In particular, in the setting where the exit pupils of the first and second light partially overlap, if there is a large difference in the color of the light, color unevenness occurs in the overlapping part of the exit pupil, but such color unevenness is observed. Can also be avoided.
[0013]
According to a second aspect of the present invention, in the first invention, the video light includes the fourth light, and the wavelength band of the fourth light is a wavelength range in which the first to third light falls. The fourth light exit pupil substantially coincides with the third light exit pupil, and the first light exit pupil and the second light exit. It is characterized by substantially matching the entire pupil.
[0014]
According to a third aspect of the present invention, there is provided the video display device according to the first or second aspect, wherein the generation means for generating the video light modulates the light from the light source that emits light with light of different wavelength bands, and the video. It includes a liquid crystal display that uses light.
[0015]
According to a fourth aspect of the present invention, there is provided the video display device according to any one of the first to third aspects, wherein a wavelength band of the first light and the second light is a third wavelength range from 600 nm to 700 nm. It is contained in.
The video display device according to a fifth aspect of the present invention is the video display device according to any one of the first to fourth aspects, wherein the first light and the second light are diffracted by the same interference fringes and have different exit pupils. It is characterized by forming.
[0016]
The video display device according to a sixth aspect of the present invention is the video display device according to any one of the first to fifth aspects, wherein the longest wavelength and the shortest wavelength in the wavelength band of the first light and the wavelength band of the second light. The difference is 100 nm or less.
According to a seventh aspect of the present invention, in the video display device according to any one of the first to sixth aspects, the wavelength band of the third light is the wavelength band of the first light and the wavelength band of the second light. It is characterized by being wider.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
First, the characteristics of the hologram will be described. There are transmissive and reflective holograms. A transmission hologram is manufactured so that light travels straight during reproduction. On the other hand, the reflection hologram can arbitrarily set the incident angle and the reflection angle (diffraction angle) of light during reproduction depending on the direction of light (laser light) during production. A reproduction optical path of a reflection hologram with an incident angle and a diffraction angle of 45 ° is shown in FIG.
[0018]
Holograms have wavelength selectivity and have a limited wavelength band that can cause diffraction. In both the reflection hologram and the transmission hologram, the width of the diffracted wavelength band depends on the refractive index modulation difference of the light-sensitive material, the film thickness, and the exposure conditions, and also depends on the incident angle of light at the time of production. However, in general, the diffraction half width of a reflection hologram is about 15 nm, and the diffraction half width of a transmission hologram is about 100 nm or more, and the former is narrower. An example of the relationship between wavelength and diffraction efficiency in a reflection hologram is shown in FIG. This is the one produced using light having a wavelength of 532 nm.
[0019]
Further, the hologram has angle selectivity, and diffracts light in a wavelength band different from that at the time of manufacture when the incident angle at the time of reproduction is different from that at the time of manufacture. When fabricated so that the diffraction angle is equal to the incident angle, the diffraction angle is equal to the actual incident angle, and the diffraction half-width is equal to the diffraction half-width at the same incident angle as that at the time of fabrication. Taking a reflection hologram as an example, the relationship between the incident angle of light during reproduction and the diffraction efficiency is shown in FIGS. This is a case where the incident angle and diffraction angle at the time of manufacture are 45 °. If the incident angle during reproduction is 45 °, light (L2) in the wavelength band centered on the wavelength during production is diffracted at a diffraction angle of 45 °, and if the incident angle during reproduction is other than 45 °, Light (L1, L3, L4) having a wavelength different from that at the time of manufacture is diffracted at a diffraction angle equal to the incident angle.
[0020]
As described above, since the hologram has a large wavelength selectivity and angle selectivity, the diffraction efficiency depends greatly on the wavelength and incident angle of light during reproduction. Accordingly, it is necessary to consider whether or not sufficient diffraction efficiency can be obtained during reproduction including light whose wavelength and incident angle are different from those at the time of fabrication. In an image display device using a hologram in an eyepiece optical system, the wavelength distribution of image light and the incident angle of image light on the hologram greatly affect the size and position of the exit pupil that defines the light beam incident on the observer's eye. On the contrary, by sufficiently taking these into consideration, the size and position of the exit pupil can be set so as to be easy to observe and to provide a high-quality image.
[0021]
Several embodiments of the video display device of the present invention will be described below. The optical configuration of the video display device of each embodiment is shown in the cross-sectional view of FIG. The video display device includes an LED (light emitting diode) 11 that is a light source, a diffusion plate 12, a condenser lens 13, an LCD (liquid crystal display) 14 that is a modulation element, a generally flat prism 15, and a hologram 16.
[0022]
Although not shown in FIG. 4, there are a plurality of LEDs 11 that emit light of different wavelength bands, and these are arranged side by side. The light emitted from each LED 11 is divergent light. The diffusion plate 12 diffuses and mixes the light from each LED 11. The condenser lens 13 makes divergent light from the LED 11 mixed by the diffusion plate 12 to be substantially parallel light.
[0023]
The LCD 14 is a transmissive type, and transmits light from the LED 11 incident through the condenser lens 13 and modulates it with the image displayed on the liquid crystal layer to obtain image light representing the image. When there are three types of LEDs 11 that emit red (R) light, green (G) light, and blue (B) light, the LCD 14 displays the R component, G component, and B component of the video alternately in time, Image light representing a color image can be obtained by causing the corresponding LED 11 to emit light in synchronization with the display. The pixels of the LCD 14 are alternately provided with three types of color filters that selectively transmit only R light, G light, and B light, and the three types of LEDs 11 are always allowed to emit light to obtain video light representing a color image. May be.
[0024]
The prism 15 is configured by joining two prisms 15a and 15b. The joint surfaces of the prisms 15a and 15b are inclined with respect to the surface, and the hologram 16 is provided on the joint surfaces. The upper end portion of the prism 15a is formed to be thicker than other portions, and the image light from the LCD 14 enters the prism 15 from the end face of this end portion. The image light that has entered the prism 15 is totally reflected by two opposing surfaces of the prism 15 and reaches the hologram 16.
[0025]
The hologram 16 is a reflection type, and reflects incident video light and guides it to the observer's eyes. The prism 15 and the hologram 16 form an eyepiece optical system, and form an exit pupil 17 in the vicinity of the observer's eye. Although not shown in FIG. 4, an exit pupil 17 exists for each light from each LED 11. The exit pupils 17 of the light from the respective LEDs 11 are set so as to be shifted from each other on the same plane, whereby the video display device has a large exit pupil as a whole.
[0026]
The hologram 16 is a volume phase type, and a photopolymer, a silver salt material, dichromated gelatin or the like can be used as the sensitive material. Among these, the photopolymer is simple because the hologram 16 can be produced by a dry process. In addition, the hologram 16 may be produced by multiplex exposure of light having different wavelengths, or may be produced by laminating light-sensitive materials individually exposed with light having different wavelengths. Multi-exposure is easy to produce, and if it is individually exposed and bonded, a product with high diffraction efficiency can be obtained.
[0027]
The external appearance of the video display apparatus 1 of each embodiment is shown in the perspective view of FIG. The video display device 1 has a glasses-like form as a whole, and is attached to a parallel plate prism 18 having substantially the same shape as the prism 15, a bridge 19 connecting the prisms 15, 18, and ends of the prisms 15, 18. In addition, a pair of temples 20, a pair of nose pads 21 attached to the bridge 19, and a housing 22 attached to the upper end of the prism 15 are provided. The housing 22 accommodates the LED 11, the diffusion plate 12, the condenser lens 13, and the LCD 14, and is connected via a cable 23 to a control unit (not shown) that controls the light emission of the LED 11 and the display of the LCD 14. .
[0028]
An observer (user) wears the video display device 1 in the same manner as glasses. Light from the outside is transmitted through the prisms 15 and 18 to both eyes of the observer, and image light from the hologram 16 is incident on one eye (in this example, the right eye). A video can be observed together with an image of the outside world. The image is observed overlaid on the image of the outside world.
[0029]
As shown in FIG. 4, the end of the prism 15a on which the hologram 16 is provided has a wedge shape, and a part of the light from the outside passes through this part, but the prism 15b is joined to the whole as a whole. Since it is a flat plate, the light transmitted through the part where the hologram 16 is provided is not refracted differently from the light transmitted through the other part, and the external image is not distorted.
[0030]
In the video display device 1, the prism 15 is used and the video light is guided by total reflection in the prism 15, so that the entire optical system is thin and lightweight. For this reason, it becomes a form suitable for mounting | wearing on a head, and an observer is hard to get tired even if it uses for a long time. Moreover, since an image of the outside world can be observed, it can be used in daily life.
[0031]
The image light guided by total reflection in the prism 15 has a large incident angle with respect to the hologram 16. For this reason, if a deviation occurs in the incident angle, the shift of the diffraction wavelength increases, and the position and size of the formed exit pupil are affected. Hereinafter, how the exit pupil of the video display device 1 is enlarged in each embodiment will be described.
[0032]
The first embodiment includes an LED 11R that emits R light and an LED 11G that emits G light. The exit pupil 17R for R light and the exit pupil 17G for G light have the same size, and the exit pupil 17R and the exit pupil 17G Only partially overlap. FIG. 6 shows the intensity distribution of the image light on the exit pupil plane and the exit pupils 17R and 17G. Such exit pupils 17R and 17G use, for example, an LED 11G that produces a hologram 16 by exposure to a laser beam having a wavelength of 647 nm and a laser beam having a wavelength of 532 nm, and emits light having a center wavelength of 635 nm and a half-value width of 20 nm. Can be obtained by using light that emits light having a center wavelength of 520 nm and a half-value width of 40 nm. In addition, let the exit pupils 17R and 17G be the intensity ranges of 50% or more of the maximum intensity of the image light.
[0033]
In the present embodiment, the exit pupil 17T as a whole is almost twice as large as the individual exit pupils 17G and 17R. Of the exit pupil 17T as a whole, a color image including the G component and the R component is observed at the center, and a monochrome image including only the G component or the R component is observed at the end.
[0034]
The diffraction half width for the R light and the diffraction half width for the G light of the hologram 16 are both about 15 nm. Therefore, most of the light from the outside is transmitted through the hologram 16, and the observer can observe the image of the outside well.
[0035]
In the second embodiment, an LED 11R that emits R light, an LED 11G that emits G light, and an LED 11B that emits B light are provided, and the exit pupils 17R, 17G, and 17B of R light, G light, and B light are all separated. The intensity distribution of the image light on the exit pupil plane and exit pupils 17R, 17G, and 17B are shown in FIGS. 7A and 7B, respectively. In the present embodiment, the exit pupil 17T as a whole is divided into three parts, and a monochrome image of only the R component, G component, or R component is observed in each part.
[0036]
The third embodiment includes two LEDs 11G1 and 11G2 that emit light having different wavelength bands while belonging to the same G light region, and include an exit pupil 17G1 for G light from the LED 11G1 and an exit pupil 17G2 for G light from the LED 11G2. Overlapping most. FIG. 8 shows the intensity distribution of the image light on the exit pupil plane and the exit pupils 17G1 and 17G2. The G light from the LED 11G1 is indicated by G1, and the G light from the LED 11G2 is indicated by G2. As such exit pupils 17G1 and 17G2, for example, a hologram 16 is produced by exposure to a laser beam having a wavelength of 532 nm, and an LED 11G1 that emits light having a central wavelength of 520 nm and a half-value width of 20 nm is used. It can be obtained by using light emitting light having a value width of 20 nm.
[0037]
In this embodiment, since the overlapping of the exit pupils 17G1 and 17G2 is large, the overall exit pupil 17T is only slightly larger than the individual exit pupils 17G1 and 17G2, but the brightness of the image is 1 LED. Nearly twice as much as when only one is provided. Further, although the wavelength bands of the light emitted from the two LEDs 11G1 and G2 are different, since both wavelength bands belong to the same G light region, a monochrome image without color unevenness in any part of the exit pupil T as a whole. Is observed.
[0038]
In the fourth embodiment, the LCD 14 is illuminated with R light, G light, and B light to provide a color image, and an LED that emits R light, an LED that emits G light, and an LED that emits B light, As in the embodiment, two light sources that belong to the same color region and emit light having different wavelength bands are provided. The exit pupil of this embodiment is shown in FIG. In FIG. 9, 17G represents the exit pupil as a whole of the two G lights, and corresponds to the exit pupil 17T of the third embodiment. 17R and 17B also represent the exit pupil as a whole of the two R lights and the exit pupil as a whole of the two B lights.
[0039]
The exit pupil 17R for the R light, the exit pupil 17G for the G light, and the exit pupil 17B for the B light substantially match, but the two exit pupils constituting each of the exit pupils 17R, 17G, and 17B are the same as those in the third embodiment. Similarly, it is partially displaced, and the exit pupil 17T as a whole is larger than any of the six exit pupils. In the present embodiment, a color image with no color unevenness is observed on the entire exit pupil 17T.
[0040]
In the fifth embodiment, the LCD 14 is illuminated with R light, G light, and B light to provide a color image. However, in the present embodiment, LEDs 11G and 11B that emit G light and B light are those having a wider emission wavelength band than LEDs that emit R light, and the exit pupil of R light thereby emits G light and B light. It is prevented by having two LEDs 17R1 and 17R2 that emit light of different wavelength bands while belonging to the same R light region. The intensity distribution of light emitted from the LEDs 11R1, 11R2, 11G, and 11B and the exit pupils 17R1, 17R2, 17G, and 17B of the light from each LED are shown in FIGS.
[0041]
The hologram 16 has three kinds of interference fringes formed by exposure of R light, G light, and B light, respectively. The single interference fringe formed by R light is the R light (R1) from the LED 11R1. Two different exit pupils 17R1 and 17R2 are formed by diffracting the R light (R2) from the LED 11R2. The exit pupil 17R1 of the R light (R1) from the LED 11R1 and the exit pupil 17R2 of the R light (R2) from the LED 11R2 partially overlap, and the exit pupil 17R as the entire R light formed by these is the G light. Substantially coincides with the exit pupil 17G of B and the exit pupil 17B of B light. Also in this embodiment, a color image with no color unevenness is observed at any part of the large exit pupil 17T as a whole.
[0042]
If one of the LEDs 11R1 and 11R2 is not provided, as is apparent from FIG. 10B, the portion of the exit pupil 17T as a whole that is far from the exit pupil 17R1 (or 17R2) has no R light and no color. Even on the exit pupil 17R1 (or 17R2), the amount of R light is smaller than the amounts of G light and B light, resulting in poor color balance and color unevenness. In the present embodiment, by providing the two LEDs 11R1 and 11R2 that emit R light, it is possible to provide an image with no color unevenness and good color balance in any part of the large exit pupil 17T. The advantage of the LEDs 11G and 11B that the wavelength band of emitted light is wide is also fully utilized.
[0043]
In the case where two LEDs that emit light in different wavelength bands belonging to the same color region are provided as in the third to fifth embodiments, the wavelength band of the light emitted by each LED is one longest wavelength and the other. It is preferable that the difference between the shortest wavelengths is about 100 nm or less. Beyond this range, the difference in color becomes large, and color unevenness is easily recognized. Moreover, if it is in the range of this wavelength difference, you may make it provide three or more light sources which emit the light of a different wavelength band.
[0044]
In each of the above-described embodiments, an example in which light from a light source is modulated by a transmissive LCD is described. However, it is also possible to modulate by a reflective LCD. The present invention is also applicable to a configuration in which the display element itself emits light representing an image, such as a CRT (cathode ray tube) display or an EL (electroluminescence) display.
[0045]
【The invention's effect】
A video display apparatus composed of an ocular optical system to provide the viewer an image represented by the image light from the raw Narute stage, and generating means for generating image light including light of a different wavelength band, the eyepiece optical system is a hologram If the exit pupils of light of different wavelength bands included in the image light are shifted from each other as in the present invention, the entire exit pupil becomes large, and the image is observed without exception. It becomes easy. Therefore, the present invention is particularly suitable for a spectacle-like form in which the relative position between the observer's eyes and the apparatus is likely to vary. In addition, since the image light includes light of a plurality of wavelength bands, a bright image can be provided while having a large exit pupil. In addition, since the exit pupil of the first light and the exit pupil of the second light partially overlap, a brighter image can be provided.
[0048]
The image light includes light of at least three wavelength bands, the first wavelength range of the first light and the second light wavelength band from 400 nm to 500 nm, and the second wavelength of 500 nm to 600 nm. And a wavelength band of the third light that falls within any one of the third wavelength range from 600 nm to 700 nm, and the wavelength band of the third light is the first wavelength range, the second wavelength range, and the third wavelength range. Of the first light exit pupil and the second light exit pupil partially overlap, the third light exit pupil and the first light exit pupil and the second light exit pupil By making it substantially coincide with the entire exit pupil of light, a color image with no color unevenness can be provided. In addition, when the generating means modulates the light from the light source to obtain the image light, it is possible to provide a color image with a good color balance while taking advantage of the light source that emits light with a particularly wide wavelength band.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing an example of a reproduction optical path of a reflection hologram.
FIG. 2 is a diagram showing an example of the relationship between wavelength and diffraction efficiency in a reflection hologram.
FIG. 3 is a diagram showing an example of the relationship between the incident angle of light during reproduction and diffraction efficiency in a reflection hologram.
FIG. 4 is a cross-sectional view showing an optical configuration of a video display device according to each embodiment of the present invention.
FIG. 5 is a perspective view illustrating an appearance of a video display device according to each embodiment.
FIG. 6 is a diagram illustrating an intensity distribution of image light and an exit pupil on an exit pupil plane of the image display apparatus according to the first embodiment.
FIG. 7 is a diagram illustrating an intensity distribution of image light and an exit pupil on an exit pupil plane of the image display apparatus according to the second embodiment.
FIG. 8 is a diagram showing an intensity distribution of image light and an exit pupil on an exit pupil plane of an image display apparatus according to a third embodiment.
FIG. 9 is a view showing an exit pupil of a video display device according to a fourth embodiment.
FIG. 10 is a diagram showing an intensity distribution and an exit pupil of light emitted from a light source according to a fifth embodiment.
[Explanation of symbols]
1 Video display device 11, 11R, 11G, 11B LED
11R1, 11R2, 11G1, 11G2 LED
12 Diffuser 13 Condenser Lens 14 LCD
15, 15a, 15b Prism 16 Hologram 17, 17R, 17G, 17B Exit pupil 17R1, 17R2, 17G1, 17G2 Exit pupil 18 Prism 19 Bridge 20 Temple 21 Nose pad 22 Housing 23 Cable

Claims (7)

A video display apparatus composed of an ocular optical system to provide the viewer an image represented by the image light from the raw Narute stage, and generating means for generating image light including light of a different wavelength band, the eyepiece optical system is a hologram Including
The first light, the second light, and the third light having at least three different wavelength bands are included in the image light,
The wavelength band of the first light and the wavelength band of the second light are a first wavelength range from 400 nm to 500 nm, a second wavelength range from 500 nm to 600 nm, and a third wavelength range from 600 nm to 700 nm. Within the same wavelength range of any one of
The wavelength band of the third light is in a wavelength range different from the wavelength range in which the first light and the second light are within the first to third wavelength ranges,
The exit pupil of the first light and the exit pupil of the second light are offset from each other and partially overlap,
An image display device, wherein the exit pupil of the third light substantially coincides with the exit pupil of the first light and the exit pupil of the second light . The image light includes fourth light, and the wavelength band of the fourth light is in a different wavelength range from the wavelength range in which the first to third light is included, and the exit pupil of the fourth light 2 substantially coincides with the exit pupil of the third light and substantially coincides with the exit pupil of the first light and the exit pupil of the second light. Video display device. Generating means for generating the image light comprises a light source for emitting a light of different wavelength bands, according to claim 1 or 2, characterized in that it comprises a liquid crystal display device that modulates the light from the light source to image light Video display device. The wavelength band of the first light and the second light, the image display device according to any one of claims 1-3, characterized in that included in the third wavelength range from 600nm to 700nm . Wherein the first light second light, the same is diffracted by the interference fringes, the image display device according to any one of claims 1-4, characterized in that to form the different exit pupil. The difference between the longest wavelength and the shortest wavelength in the wavelength band of the first light and the wavelength band of the second light is 100 nm or less. Video display device. The video display device according to claim 1, wherein the wavelength band of the third light is wider than the wavelength band of the first light and the wavelength band of the second light. .

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