JP3298324B2 - Image display device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image display apparatus using a liquid crystal panel, and more particularly to an effective image display when applied to a viewfinder of a camera-integrated VTR or a retinal direct display apparatus for projecting an image directly on the retina of an eyeball. It concerns the device.

[0002]

2. Description of the Related Art In recent years, with the development of electronic technology and increasing needs of users, miniaturization and power saving of electronic devices have been progressing. Under these circumstances, the camera-integrated VTR (video tape recorder) and the head-mounted display are required to be further reduced in size and power consumption from the usage form. A color liquid crystal panel is mainly used for a viewfinder and a head mounted display of this camera-integrated VTR, and a backlight is arranged close to the back of the color liquid crystal panel. The user can visually recognize an image projected on a color liquid crystal panel by the irradiation light of the backlight. As the backlight light source, for example, a cold cathode lamp or a surface type arc tube is used, and these cold cathode lamps and the surface type arc tube are fluorescent discharge tubes utilizing a discharge phenomenon. Requires a high-voltage power supply, and is usually lit using a converter (DC-AC converter) that converts DC power to AC power of several hundred volts.

On the other hand, a light emitting diode (Light Em)
Iting Diode (hereinafter simply referred to as “LED”) has been improved in luminance year by year, and the three primary colors red (R), green (G), and blue (B) (hereinafter simply referred to as “R”) ,
G, B ”), which is a display in which all the emission colors are constituted by LEDs, is approaching. This LED is electric-
A solid-state functional device for light conversion, a semiconductor light-emitting element utilizing minority carrier injection at a pn junction formed by adjacent p and n-type semiconductor crystals and subsequent light-emitting recombination, In particular, it has excellent compatibility with other semiconductor elements,
It has features such as small size, high reliability, and high-speed response. The present invention seeks to utilize LEDs having these excellent features as a backlight source for a liquid crystal panel.

[0004]

However, a cold cathode lamp or a surface-type arc tube, which is a backlight source of the prior art as described above, requires a high voltage power supply for lighting, and an electromagnetic field generated from the high voltage power supply is required. It is necessary to take measures such as electromagnetic shielding against noise. Further, these fluorescent discharge tubes have a problem that it is difficult to light in a dark state or at a low temperature.

On the other hand, in an image display device used for a viewfinder or a head mounted display of a camera-integrated VTR, the display element is changed from a monochrome CRT to a color liquid crystal panel, so that the power of the color liquid crystal panel itself as a display element is changed. Although the consumption can be greatly reduced, the backlight light source that supplies light to the color liquid crystal panel as described above uses a surface-type arc tube or a cold cathode lamp with a reflector (or a light guide plate). Since it is used in a form converted to surface light emission, there is a drawback that efficiency is low and wasteful power is easily consumed. Further, the life of the cold cathode lamp and the surface type arc tube is about 2000 hours, and there is a limit in terms of the life.

The present invention has been made in view of the above points, and eliminates the need for an electromagnetic shield against electromagnetic noise in a conventional backlight light source, and eliminates the need for measures against non-lighting in the dark or at low temperatures. Another object of the present invention is to solve the disadvantages of the conventional backlight source, such as the short usable time of the device due to the large power consumption and the short life of the backlight source itself. is there.

[0007]

According to a first aspect of the present invention, there is provided an image display apparatus comprising: a light source;
An image display device having an optical path including a color liquid crystal panel and irradiating the color liquid crystal panel with light emitted from the light source so that an image is viewed by a convex lens. , Green (G) and blue (B) LEs
D and means for optically combining light , said light source
The light emitted from each of the red (R), green (G), and blue (B) LEDs is transmitted or reflected by the optically combining means provided in the optical path, thereby optically emitting light. so as to be synthesized in the street, an image display apparatus so as to induce in the color liquid crystal panel, here
The first half-mirror is used as the optically combining means.
A first half mirror having a mirror and a second half mirror.
Is tilted with respect to the optical path, inserted into the optical path,
Light emitted from the LED passes through the first half mirror.
And the light emitted from the second LED is
The light is reflected by a mirror, and these lights are combined to form a second harmonic.
Reflected by the mirrors and emitted from the third LED.
The reflected light passes through the second half mirror, and thus,
The three primary colors of R, G and B are combined on one optical axis and
The red (R), green
(G), blue (B) LEDs and the first and second LEDs.
It is characterized by the provision of a mirror .

The image display apparatus according to a second aspect of the present invention has an optical path including a light source and a color liquid crystal panel, and irradiates the color liquid crystal panel with light emitted from the light source. In an image display apparatus in which an image is viewed with a convex lens, the light source is configured by red (R), green (G), and blue (B) LEDs and a unit that optically combines light, and Each L of red (R), green (G), blue (B)
Light emitted from the ED is transmitted or reflected by the optically combining means provided in the optical path, so that the light is optically combined on the optical path and guided to the color liquid crystal panel. With the image display device
There, wherein the means for combining the said optical
G reflection dichroic mirror and R reflection dichroic
With a G mirror and four G dichroic mirrors
5 ° tilted and inserted on the optical path, the green LED light
The color liquid is totally reflected by the dichroic mirror
Is guided to the crystal panel and a dichroic mirror with R reflection
Inserted on the optical path by inclining by 45 °, the light of the red LED is R
Color is totally reflected by the reflective dichroic mirror
Guided by the liquid crystal panel, the light of the blue LED reflects
Position that passes through the dichroic mirror
From the red (R), green (G) and blue (B) LEDs
The red light is emitted so that the emitted light is combined on one optical axis.
(R), green (G), blue (B) LEDs and the G reflection
And an R reflection dichroic mirror is provided.

According to a third aspect of the present invention, there is provided an image display apparatus comprising:
A light source, having an optical path comprising a color liquid crystal panel,
In an image display device in which light emitted from the light source is applied to the color liquid crystal panel so that an image is viewed with a convex lens, the light sources are red (R), green (G), and blue (B).
LED and means for optically combining light,
Light emitted from each of the red (R), green (G), and blue (B) LEDs of the light source is transmitted or reflected by the optically combining means provided in the optical path,
An image display device that is optically synthesized on an optical path and guided to the color liquid crystal panel.
Black Te, wherein the means for combining the said optical
A cross dichroic mirror with a dichroic mirror
Mirrors are dichroic mirrors with G reflection and R reflections.
Combine the dichroic mirrors so that they are orthogonal to each other
A dike for the G reflection and the R reflection.
Tilt the Loic mirror 45 ° and insert it on the optical path,
The light of the green LED is reflected by a dichroic mirror that reflects G light.
The light is totally reflected and guided to the color liquid crystal panel,
The LED light is completely reflected by the R reflection dichroic mirror
The blue LED
Is reflected by the G reflection and R reflection dichroic mirrors.
Passing through the red (R), green (G), blue
The light emitted from each LED of (B) is combined on one optical axis.
So that each of the red (R), green (G), and blue (B) L
ED and cross dichroic of G reflection and R reflection
It is characterized by having a mirror . In the image display device according to a fourth aspect of the present invention, the light emitted from each of the red (R), green (G), and blue (B) LEDs is transmitted or reflected by the optically combining means. Therefore, it is characterized in that it is disposed so as to be located at a position where it is optically emitted from one point. Further, the claims of the present invention
Item 5. The image display device according to Item 5 , wherein the red (R), green (G),
Light emitted from each of the blue (B) LEDs is irradiated on the color liquid crystal panel, and an image is projected on a retina of an eyeball via an eyepiece so that the image can be viewed.

[0010] The image display device according to claim 6 of the present invention comprises:
In an image display apparatus having an optical path including a light source and a black-and-white liquid crystal panel, and irradiating light emitted from the light source to the black-and-white liquid crystal panel so that an image is viewed with a convex lens, the light source is red. (R), green (G), and blue (B) LEDs, and means for optically combining light.
The light emitted from each of the red (R), green (G), and blue (B) LEDs of the light source is transmitted or reflected by the optically combining means provided on the optical path, thereby optically. It is arranged so as to be synthesized on the optical path and guided to the black and white liquid crystal panel, and is synchronized with the sequential light emission of each of the red (R), green (G) and blue (B) LED light sources. the red to the black-and-white liquid crystal panel (R), green (G), and image so as to sequentially display each color video signal of blue (B)
A display device , wherein the optically combining is performed.
First half mirror and second half mirror as means
Having a first half mirror on the optical path,
And the light emitted from the first LED is
The light passes through the first half mirror and exits from the second LED.
The emitted light is reflected by the first half mirror, and
Are combined and reflected together by the second half mirror,
The light emitted from the third LED is the second half.
It passes through the mirror, and thus the three primary colors of R, G and B are one
Combined on the optical axis of
Thus, each of the red (R), green (G), and blue (B) LEDs
And the first and second half mirrors are provided.

An image display device according to a seventh aspect of the present invention comprises:
In an image display apparatus having an optical path including a light source and a black-and-white liquid crystal panel, and irradiating light emitted from the light source to the black-and-white liquid crystal panel so that an image is viewed with a convex lens, the light source is red. (R), green (G), and blue (B) LEDs, and means for optically combining light.
Light emitted from each of the red (R), green (G), and blue (B) LEDs of the light source is transmitted or reflected by the optically combining means provided in the optical path, so that the light is optically transmitted. It is arranged so as to be synthesized on the optical path and guided to the black and white liquid crystal panel, and is synchronized with the sequential light emission of each of the red (R), green (G) and blue (B) LED light sources. the red to the black-and-white liquid crystal panel (R), green (G), and image so as to sequentially display each color video signal of blue (B)
A display device , wherein the optically combining is performed.
As means, G reflection dichroic mirror and R reflection
Dichroic with dichroic mirror and G reflection
Insert the mirror on the optical path by tilting the mirror by 45 °, green LED
Light is totally reflected by the G reflection dichroic mirror
Dichroic with R reflection
The mirror is tilted at 45 ° and inserted on the optical path,
ED light is totally reflected by R reflection dichroic mirror
To the black and white liquid crystal panel,
Passes through the G reflection and R reflection dichroic mirrors
The red (R), green (G), and blue (B)
The light emitted from each LED is combined on one optical axis.
The red (R), green (G), and blue (B) LEDs and
And dichroic mirrors for G reflection and R reflection
It is characterized in that the. According to claim 8 of the present invention ,
Such an image display device is characterized in that the monochrome liquid crystal panel is a ferroelectric liquid crystal.

[0012]

According to the image display device of the present invention , red (R),
By arranging the green (G) and blue (B) LEDs substantially on the optical axis of the color liquid crystal panel or substantially at one point on the optical axis, an image can be viewed.

Light emitted from each of the R, G, and B LEDs
Are transmitted or reflected by means of optical synthesis.
The light is optically emitted from one point.

Light emitted from each of the R, G, and B LEDs
To the color LCD panel, and
You can project an image directly on the retina of the sphere and see the image
Wear.

Further, in the image display device of the present invention,
A black and white liquid crystal panel is provided instead of the liquid crystal panel,
The black and white liquid crystal is synchronized with each of the R, G, and B LED light sources.
A so-called plane that displays video signals of R, G, and B colors on a panel
They can be displayed sequentially.

Further, as a monochrome liquid crystal panel, a ferroelectric
Liquid crystals can be used.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an image display device according to the present invention will be described below with reference to FIGS. First, a first embodiment will be described with reference to FIGS.

Embodiment 1 First, the configuration and operation of an image display device according to the present invention will be described with reference to FIG. FIG. 1 is an example of an image display device according to the present invention. This image display device is roughly composed of a viewfinder section 1 and a main body section 2 in which an image processing, an LED drive circuit and the like are inserted. The detailed configuration of the viewfinder unit 1 includes an eyecup 4, an eyepiece 5, a diopter adjuster 6 for adjusting the eyepiece 5 back and forth, and the like. Further, although not shown, a liquid crystal panel and a backlight which is an object of the present invention are built in the viewfinder unit 1.

A battery 3 for supplying power to the image display device is mounted on the main body 2, and a power switch 7 for controlling on / off of the power of the image display device, and R and G backlights are provided. , B, and an input terminal 9 for inputting a desired video signal. Since the video display device of the present invention allows the user to view a video only by inputting a video signal, the video display device can be used for purposes such as checking the screen of the surveillance video camera when installing the surveillance video camera.

Next, the details of the optical system of the viewfinder 1 will be described with reference to FIGS. FIG. 2 is an exploded perspective view of the optical system of the present embodiment, and FIG. 3 is a schematic diagram for explaining the optical system. Hereinafter, the same parts in the drawings related to the description of the optical system are denoted by the same reference numerals,
A description of those configurations and operations will be omitted.

Reference numeral 10 in FIG. 2 denotes a color liquid crystal panel, and a user projects an image on a screen 11 of the color liquid crystal panel 10 through a convex lens 12 and an eyepiece 5 arranged close to the color liquid crystal panel 10. The image to be viewed is visually recognized with the eyeball 13. Reference numeral 14 denotes a backlight unit, which is a light source such as a red LED 15, a blue LED 16, and a green LED.
17, the half mirror 18 and the half mirror 19, and the diffusion plates 20 and 21 are integrally combined. The red LED 15, the blue LED 16, and the green LED 17 are arranged such that the light combined by the half mirrors 18 and 19 is approximately at a position where the light is optically emitted from one point as shown in FIG. ing.

In FIG. 2 and FIG.
The light emitted from the blue LED 16 is transmitted through the half mirror 18, and the light emitted from the blue LED 16 is reflected by the half mirror 18. These lights are combined and reflected together by the half mirror 19 to form the color liquid crystal panel 10. Guided to the side. The light emitted from the green LED 17 passes through the half mirror 19. In this way, the three primary colors of R, G, and B are combined, condensed on the screen 11 of the color liquid crystal panel 10, and used for a backlight.

The image display apparatus of this embodiment employs an optical system similar to the optical system disclosed in Japanese Patent Application Laid-Open No. Hei 5-80331 filed by the present applicant. Since this optical system is a simple point light source system using a Ramsden eyepiece, it is not necessary to exactly match the incident light points from the red LED 15, the blue LED 16, and the green LED 17, and as shown in FIG. The same effect can be obtained by inserting thin diffusion plates 20 and 21 on the optical path of the green LED 17 and inserting, for example, Scotch mending tape (registered trademark of US 3M). The details of the Ramsden eyepieces are described in “Knowledge of Optics”, page 124, by Kogoro Yamada, published by Tokyo Denki University Press.

In the point light source system used in the retinal direct display device described later, there is no need to adjust the diopter in principle. However, since the present optical system is a simple point light source system, the diopter adjuster shown in FIG. It is necessary to adjust the diopter by rotating the eyepiece 5 by rotating the eyepiece 6 in the front-rear direction. In that case, when the diopter adjuster 6 in FIG. 1 is rotated, the eyepiece 5 in FIG. 2 moves in the X direction to adjust the diopter. Further, in the present optical system, it is effective that the incident intersection of the red LED 15, the blue LED 16, and the green LED 17 is not one point but coincides with the optical axis.

In this embodiment, a high luminance type having a luminous intensity of 1 cd, manufactured by Nichia Corporation, was used for the blue LED 16. The details of the blue LED are described in JP-A-5-15-1.
No. 10138 is disclosed. Red LED1
5 and the green LED 17 were high-brightness types manufactured by Hewlett-Packard Company. FIG. 13 shows a spectrum diagram of these LEDs.

Further, the configuration and operation of the image display circuit of the present invention will be described with reference to FIG. The illustrated image display circuit,
A power supply 31 for driving a liquid crystal panel, a power supply 32 for LEDs, a power supply 30 that supplies these power supplies, and an LED driver circuit 3
3, a light emitting amount controller 8 connected to the LED driver circuit 33, a red LED 15, a blue LED 16, and a green LED 1.
7 and an input terminal 9 for receiving an external video signal
And an RGB process circuit 34, and a controller circuit 35 for controlling the color liquid crystal panel 10.

The video signal received from the input terminal 9 is input to an RGB process circuit 34, where signal processing such as chroma processing is performed, and further, the composite signal is converted into an RGB separate signal suitable for driving the color liquid crystal panel 10. I do. Similarly, the AC signal is converted into an AC signal suitable for driving the color liquid crystal panel 10 and the AC signal is supplied to the color liquid crystal panel 10. The RGB separate signal is input to the controller circuit 35, and the controller circuit 3
5, the color liquid crystal panel 1
The color liquid crystal panel 10 is driven via the X driver circuit and the Y driver circuit of No. 0.

A red LED 15, a blue LED 16, and a green LED 17 for supplying light to the color liquid crystal panel 10 are LEDs.
The light is turned on by the driver circuit 33. The light emission amounts of the red LED 15, the blue LED 16, and the green LED 17 can be respectively adjusted by a light emission amount adjuster 8. In this embodiment, the light emission amounts are adjusted in advance by the light emission amount adjuster 8, and are incident on the color liquid crystal panel 10. Incident light amount is almost
Adjustment is made to B: G: R = 1: 6: 3. In addition,
The power supply 31 for driving the liquid crystal panel and the power supply 32 for the LED are turned on / off by a switch 36 provided in the power supply 30.

Embodiment 2 This embodiment is an example in which a dichroic mirror is used in place of the half mirror in the first embodiment. This will be described with reference to FIGS. The dichroic mirror has a function of selecting and reflecting a desired specific wavelength by coating a glass substrate surface with various dielectric multilayer films.
When it is tilted by 5 ° and inserted on the optical path, it reflects a specific wavelength,
Other wavelengths serve to transmit light.

5 and 6, reference numeral 10 denotes a color liquid crystal panel, 11 denotes a screen thereof, 12 denotes a convex lens, 5 denotes an eyepiece, and 13 denotes an eyeball. Further, reference numerals 15, 16, and 17 indicate a red LED and a blue L, respectively.
ED, green LED. Reference numerals 22 and 23 are dichroic mirrors which are characteristic portions of the present embodiment, reference numeral 22 is a G reflection dichroic mirror, and reference numeral 23 is an R reflection dichroic mirror.

With the present embodiment configured as described above,
The operation will be described below. The light emitted from the green LED 17 is totally reflected by the action of the G-reflecting dichroic mirror 22, and becomes an R-reflecting dichroic mirror 2.
3 is transmitted and guided to the color liquid crystal panel 10 side. Similarly, the light emitted from the red LED 15 is totally reflected by the R reflection dichroic mirror 23 and guided to the color liquid crystal panel 10 side. Since the light emitted from the blue LED 16 is blue (B) light, it passes through both the dichroic mirror 22 for the G reflection and the dichroic mirror 23 for the R reflection. In this way, the three primary colors of R, G and B are combined and emitted to the color liquid crystal panel side.

In this embodiment, by using the dichroic mirror as described above, there is no light loss and the light use efficiency is improved as compared with the case where the half mirror of the first embodiment is used. In other words, when using a half mirror,
1/2 to 1 of the amount of light incident on the color liquid crystal panel 10
Although the light amount of ３ is wasted, when a dichroic mirror is used, it is accurately separated for each emission wavelength and enters the color liquid crystal panel, so that the light amount is not wasted.
In addition, since the spectrum of the reflected light component can be limited, the spread of the emission spectrum of each of the R, G, and B LEDs can be suppressed, and the required color component can be selected and extracted. is there.

Embodiment 3 This embodiment is an example in which a black-and-white liquid crystal panel is used instead of the color liquid crystal panel in the above-mentioned two embodiments, and a plane-sequential method is adopted as a driving method of the black-and-white liquid crystal panel. 5
This will be described with reference to FIG. The optical system of the present embodiment employs the optical system using the dichroic mirror of the second embodiment (the description of the optical system is omitted because it is redundant), but the half mirror of the first embodiment is omitted. It goes without saying that the used optical system is also applicable.

In this embodiment, as shown in FIG. 7, a black and white liquid crystal panel 100 is used as a liquid crystal panel for displaying an image, and R, G, and B LEDs are used as a backlight as shown in FIGS. And a dichroic mirror were integrated, and each LED was used in an individually lit state. That is, the monochrome liquid crystal panel 1 as shown in FIG.
00, video signals of R, G, and B colors are applied, and the red LED 15, the blue LED 16, and the green L are synchronized with the video signals.
If the LEDs of the ED 17 emit light sequentially, a desired color image can be obtained. In this case, the liquid crystal panel has an advantage that the resolution is tripled because no color filter is required. Further, since the backlight in this case emits monochromatic light, it is possible to limit the power consumption to an extremely low level.

The configuration and operation of the image display circuit according to the present embodiment will be described with reference to FIG. The same parts as those in FIG. 4 are denoted by the same reference numerals, and the description of their configuration and operation will be omitted. The illustrated image display circuit includes an input terminal 9 for receiving a video signal from the outside, a power supply 31 for driving a liquid crystal panel, a power supply 32 for LEDs, a power supply 30 that supplies these power supplies, a switch 36, and RGB. A process circuit 34 is provided as the same component. Furthermore, a black-and-white liquid crystal panel 100, a controller circuit 102 for controlling the black-and-white liquid crystal panel 100, an LED driver circuit 103, a light emission amount adjuster 8 connected to the LED driver circuit 103, a red LED 15, a blue LED 16, and a green LED 17 ,
A video memory 101 is newly provided.

Then, the video signal received from the input terminal 9 is input to an RGB process circuit 34, where signal processing such as chroma processing is performed. Further, the composite signal is separated into RGB separate signals suitable for driving the monochrome liquid crystal panel 100. I do. The video signal separated into the RGB separate signals is temporarily stored in the image memory 101. Under the control of the controller circuit 102, when the red LED 15 is turned on, the R video signal is applied to the black and white liquid crystal panel 100, and similarly, predetermined LEDs are sequentially turned on for B and G to synchronize with the black and white. Through the X driver circuit and the Y driver circuit of the liquid crystal panel 100, the monochrome liquid crystal panel 1
An image is displayed at 00. In this case, the monochrome liquid crystal panel 10
The video signal applied to 0 is, for example, an AC signal at a triple speed for one field.

By adopting such a driving method, the image projected on the black-and-white liquid crystal panel 100 is R, G,
Since each emission color of B is illuminated as a backlight, the resolution is tripled and the color development becomes beautiful. However, the current technology is 1
Although the response speed of a liquid crystal capable of switching three images in a field has not been realized, a ferroelectric liquid crystal (FLC: Ferr)
roleLiquid Crystal
The high-speed liquid crystal system represented by has been developed, and the future is expected.

Embodiment 4 This embodiment is an example in which a cross dichroic mirror is employed in place of the half mirror in Embodiment 1 and the dichroic mirror in Embodiment 2 and FIG.
This will be described with reference to FIG. The cross dichroic mirror is an optical component having a structure in which dichroic mirrors are accurately combined.

The cross dichroic mirror 40 shown in FIGS. 8 and 9 is a G reflection dichroic mirror 40G.
And the R-reflecting dichroic mirror 40R are accurately combined so as to be perpendicular to each other. The red LED 15, blue LED 16, green L arranged as shown in FIG.
The light emitted from, for example, the green LED 17 of the ED 17 is caused by the action of the G reflection dichroic mirror 40G.
The light is totally reflected and guided to the color liquid crystal panel 10 side. Similarly, the light emitted from the red LED 15 is totally reflected and guided to the color liquid crystal panel 10 by the action of the R-reflecting dichroic mirror 40R. Furthermore, blue LED 16
Is blue (B) light, the light passes through both the G-reflecting dichroic mirror 40G and the R-reflecting dichroic mirror 40R, and is guided to the color liquid crystal panel 10 side. The primary colors are combined on the optical path.

As described above, the use of the cross dichroic mirror makes it possible to reduce the light loss as compared with the case of using the half mirror of the first embodiment, as in the case of using the dichroic mirror of the second embodiment. There is no light and the light use efficiency is improved. Further, by using the cross dichroic mirror, a structure for holding the half mirror and the dichroic mirror becomes unnecessary, and the backlight unit can be made compact.

Embodiment 5 In this embodiment, the light source system of the present invention is a "simple point light source system" using a Ramsden eyepiece, while the light source system of the present invention is a "eyeball retina direct display device using a point light source". This will be described with reference to FIGS. 10 and 11. FIG. The details of an eyeball retina direct display apparatus using a point light source are described in detail in Japanese Patent Application Laid-Open No. 2-136 filed by the present applicant.
Japanese Patent Application Laid-Open No. Hei.
No. 2,148,872 discloses a “glass-type retinal direct display device”.

10 and 11, reference numeral 50 denotes a backlight portion, 51 and 52 denote convex lenses, and 53 denotes a liquid crystal panel (regardless of the type of a monochrome liquid crystal panel or a color liquid crystal panel). Reference numerals 54 and 55 are convex lenses, 13 is an eyeball, and 56 is a retina of the eyeball 13.

The operation of the backlight 50 having the same structure as that of the second embodiment will be described. The green LED 17
Since the light emitted from the LED is green (G) light, the light is totally reflected by the action of the G-reflecting dichroic mirror 22 and guided to the front. Similarly, the light emitted from the red LED 15 is
Since it is red (R) light, an R-reflecting dichroic mirror 2
The light is totally reflected by the action of No. 3 and is guided to the front surface. The light emitted from the blue LED 16 is blue (B) light,
Both the reflecting dichroic mirror 22 and the R reflecting dichroic mirror 23 pass through. Furthermore, the blue LE
The light emitted from D16 and the light emitted from the green LED 17 pass through the R reflection dichroic mirror 23. In this way, the three primary colors of R, G, and B are combined exactly at one point.

The point light source composed of the three primary colors emitted from the backlight unit 50 is condensed by a convex lens 51, converted into parallel light by a convex lens 52, and is incident on a liquid crystal panel 53. Light rays including an image passing through the liquid crystal panel 53 are condensed by the convex lenses 54 and 55, and
Focus on the pupil located on the surface of
The image reaches the third retina 56 and forms an image. FIGS. 10 and 11 show principle diagrams of the present embodiment. If a light beam is refracted using a mirror or the like, a thin glasses-type display device can be realized.

The amount of backlight in this embodiment is smaller than that of a normal cold cathode lamp, for example. However, in the backlight system of this embodiment, an image is projected and displayed directly on the retina of the eyeball by a point light source. Therefore, it is possible to clearly see an image even with a small amount of backlight.

The present invention is not limited to the above-described embodiment, but can employ various embodiments. For example, in the above embodiment,
Although the image display apparatus as shown in FIG. 1 has been described, the present invention can be applied as a viewfinder by interpolating into the viewfinder section 1 of the camera-integrated VTR 60 as shown in FIG. Although not shown, two image display devices of the present invention may be provided side by side to form a spectacle type image display device, and furthermore, the device can be applied as a stereoscopic display device by displaying a stereoscopic image on the same device.

In the above-described embodiment, a liquid crystal panel is exemplified as a display device. However, other transmissive display devices may be used. Further, by changing the arrangement of a backlight portion, a reflective liquid crystal panel or a reflective display device may be used. It goes without saying that it can be applied.

[0048]

As described above, according to the image display apparatus of the present invention, like the conventional backlight light source,
No high-voltage power supply for lighting is required. Therefore, there is no electromagnetic noise generated from the high-voltage power supply, and no measures such as an electromagnetic shield are required. Further, there is no problem that these fluorescent discharge tubes have poor lighting properties in a dark state or at a low temperature.

Further, by using an LED as a backlight light source, the LE is excellent in compatibility with a liquid crystal panel composed of semiconductor elements, and is small in size, high in reliability and high in response speed.
The characteristics of D can be used as it is. In addition, LED
The power consumption is low and the power consumption can be greatly reduced from 0.5 to 0.7 W of the conventional backlight to 0.1 W or less. In this way, the battery life of the device can be significantly extended, and the lifetime of the backlight light source itself can be greatly extended from several thousand hours to several tens of thousands hours of the conventional backlight.

In particular, when the point light source of the image display device of the present invention is used such that the pupil is located at the focal point of the eyepiece, the image on the liquid crystal panel can be sharpened regardless of the diopter (myopia, hyperopia) of the individual. It becomes possible to see. In addition, since the viewing angle can be set up to 60 °, it is possible to view a powerful image as if a large screen is approached.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a first embodiment of the present invention.

FIG. 2 is an exploded perspective view of the first embodiment of the present invention.

FIG. 3 is a schematic diagram for explaining an optical system according to a first example of the present invention.

FIG. 4 is a circuit diagram used in the first embodiment of the present invention.

FIG. 5 is an exploded perspective view of a second embodiment of the present invention.

FIG. 6 is a schematic diagram for explaining an optical system according to a second example of the present invention.

FIG. 7 is a circuit diagram used in a third embodiment of the present invention.

FIG. 8 is an exploded perspective view of a fourth embodiment of the present invention.

FIG. 9 is a top view for explaining an optical system according to a fourth embodiment of the present invention.

FIG. 10 is an exploded perspective view of a fifth embodiment of the present invention.

FIG. 11 is a schematic diagram for explaining an optical system according to a fifth embodiment of the present invention.

FIG. 12 is a perspective view showing an example of the embodiment of the present invention.

FIG. 13 is a spectrum diagram of a high-brightness LED which is a component of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 View finder part 2 Body part 3 Battery 4 Eye cup 5 Eyepiece 6 Diopter adjuster 7 Power switch 8 Emission amount adjuster 9 Input terminal 10 Color liquid crystal panel 11 Screen 12, 51, 52 Convex lens 54, 55 Convex lens 13 Eyeball 14 , 50 backlight part 15 red LED 16 blue LED 17 green LED 18, 19 half mirror 20, 21 diffuser 22, 40G dichroic mirror for G reflection 23, 40R dichroic mirror for R reflection 30 power supply 31 liquid crystal panel drive power supply 32 LED Power supply 33, 103 LED driver circuit 34 RGB process circuit 35, 102 Controller circuit 36 Switch 40 Cross dichroic mirror 53 Liquid crystal panel 56 Retina 60 Camera-integrated VTR 100 Monochrome liquid crystal panel 101 Video memory

────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁷ Identification code FI G03B 33/12 H01L 33/00 M H01L 33/00 G02F 1/1335 530 (56) References JP-A-3-56922 (JP, A) JP-A-62-131232 (JP, A) JP-A-6-148635 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G02F 1/13 505 G02B 27/02 G02F 1/133 535 G02F 1/13357 G03B 21/132 G03B 33/12 H01L 33/00

Claims (8)

(57) [Claims] 1. An image display device having an optical path including a light source and a color liquid crystal panel, and irradiating light emitted from the light source to the color liquid crystal panel so that an image is viewed by a convex lens . The light sources are red (R), green (G), and blue (B) LEDs, respectively.
And a means for optically synthesizing light, and the light emitted from each of the red (R), green (G), and blue (B) LEDs of the light source is optically synthesized in the optical path. By being transmitted or reflected by
An image display device that is optically synthesized on an optical path and guided to the color liquid crystal panel.
Te, wherein the first wafer as a means for synthesizing on the optical
A first mirror having a half mirror and a second half mirror.
Tilt the mirror to the optical path and insert it on the optical path,
The light emitted from the first LED is the first half mirror.
And the light emitted from the second LED passes through the first LED.
Are reflected by the half mirror of
Reflected by the half mirror, and from the third LED
The emitted light passes through the second half mirror, and
Then, the three primary colors R, G, and B are combined on one optical axis.
As it can be subjected to backlight applications, the red (R), green (G), and each LED and the blue (B)
An image display device comprising a first half mirror and a second half mirror . 2. An image display apparatus having an optical path including a light source and a color liquid crystal panel, and irradiating light emitted from the light source to the color liquid crystal panel so that an image can be viewed with a convex lens . The light sources are red (R), green (G), and blue (B) LEDs, respectively.
And a means for optically synthesizing light, and the light emitted from each of the red (R), green (G), and blue (B) LEDs of the light source is optically synthesized in the optical path. By being transmitted or reflected by
An image display device that is optically synthesized on an optical path and guided to the color liquid crystal panel.
Te, wherein the G reflection as a means for synthesizing on the optical
Dichroic mirror and dichroic mirror with R reflection
Tilt the dichroic mirror of G reflection by 45 °
Then, it is inserted on the optical path and the light of the green LED is
Color LCD panel that is totally reflected by the croic mirror
Is induced in the optical path by 45 ° tilted dichroic mirrors R reflection
Dichroic with R-reflected red LED light inserted above
The light is totally reflected by the mirror and guided to the color LCD panel.
The light of the blue LED is the dichroic light of G reflection and R reflection.
A position passing through a mirror, the red (R) and the green
The light emitted from each of the (G) and blue (B) LEDs has one optical axis.
As synthesized above, the red (R), green (G), blue (B) LEDs and the
An image display device comprising a dichroic mirror for G reflection and R reflection . 3. An image display device having an optical path including a light source and a color liquid crystal panel, wherein light emitted from the light source is applied to the color liquid crystal panel so that an image is viewed with a convex lens . The light sources are red (R), green (G), and blue (B) LEDs, respectively.
And a means for optically synthesizing light, and the light emitted from each of the red (R), green (G), and blue (B) LEDs of the light source is optically synthesized in the optical path. By being transmitted or reflected by
An image display device that is optically synthesized on an optical path and guided to the color liquid crystal panel.
Te, wherein Kurosuda as a means for synthesizing on the optical
Cross dichroic with ichroic mirror
The mirror is a dichroic mirror with G reflection and a die with R reflection.
Combined with the Croix mirror so that they are orthogonal to each other
Be those that Tsu, 45 ° dichroic mirrors of the G reflection, and R reflection
Tilted and inserted on the optical path, the light of the green LED is reflected by the G reflection dichroic mirror
Be more totally reflected is derived from to over the liquid crystal panel, the light of the red LED on the dichroic mirror for R reflector
The light of the blue LED is totally reflected and guided to the color liquid crystal panel, and the light of the blue LED is dichroic of the G reflection and the R reflection.
From the red (R), green (G), and blue (B) LEDs.
The red (R), green (G), and blue (B) LEDs and the
G reflection and R reflection cross dichroic mirrors installed
The image display apparatus characterized by the. 4. The light emitted from each of the red (R), green (G), and blue (B) LEDs is transmitted or reflected by the optically synthesizing means, so that the light is optically substantially from one point. 4. The image display device according to claim 1 , wherein the image display device is disposed so as to be at a position where light is emitted. 5. The color liquid crystal panel is irradiated with light emitted from the red (R), green (G), and blue (B) LEDs, and an image is projected on a retina of an eye via an eyepiece. 4. The image display device according to claim 1 , wherein the image is made visible. 6. An image display apparatus having an optical path including a light source and a black and white liquid crystal panel, and irradiating light emitted from the light source to the black and white liquid crystal panel so that an image can be viewed with a convex lens . The light sources are red (R), green (G), and blue (B) LEDs, respectively.
And a means for optically synthesizing light, and the light emitted from each of the red (R), green (G), and blue (B) LEDs of the light source is optically synthesized in the optical path. By being transmitted or reflected by
The red (R), green (G), and blue (B) LED light sources are sequentially arranged so as to be optically combined on an optical path and guided to the monochrome liquid crystal panel. An image display device in which video signals of the respective colors of red (R), green (G), and blue (B) are sequentially displayed on the black and white liquid crystal panel in synchronization with each other , wherein the optically combining is performed. As a means for performing
A first mirror having a half mirror and a second half mirror.
A mirror is disposed on the optical path, tilted with respect to the optical path.
The light emitted from the first LED is the first half.
The light passing through the mirror and emitted from the second LED is
The light is reflected by the first half mirror, and these lights are combined.
Reflected together by the second half mirror, and the third LED
The light emitted from passes through the second half mirror,
Thus, the three primary colors of R, G, and B are combined on one optical axis.
The red (R), green (G), and blue (B) LEDs and the
An image display device comprising a first half mirror and a second half mirror . 7. An image display apparatus having an optical path including a light source and a black and white liquid crystal panel, wherein light emitted from the light source is applied to the black and white liquid crystal panel so that an image is viewed with a convex lens . The light sources are red (R), green (G), and blue (B) LEDs, respectively.
And a means for optically synthesizing light, and the light emitted from each of the red (R), green (G), and blue (B) LEDs of the light source is optically synthesized in the optical path. By being transmitted or reflected by
The red (R), green (G), and blue (B) LED light sources are sequentially arranged so as to be optically combined on an optical path and guided to the monochrome liquid crystal panel. An image display device in which video signals of the respective colors of red (R), green (G), and blue (B) are sequentially displayed on the black and white liquid crystal panel in synchronization with each other , wherein the optically combining is performed. G reflection
Dichroic mirror and dichroic mirror with R reflection
Tilt the dichroic mirror of G reflection by 45 °
Then, it is inserted on the optical path and the light of the green LED is
The black-and-white liquid crystal panel is totally reflected by the
Induced Le, the optical path by 45 ° tilted dichroic mirrors R reflection
Dichroic with R-reflected red LED light inserted above
The light is totally reflected by the mirror and guided to the monochrome LCD panel.
The light of the blue LED is the dichroic light of G reflection and R reflection.
From the red (R), green (G), and blue (B) LEDs.
The red (R), green (G), and blue (B) LEDs and the
An image display device comprising a dichroic mirror for G reflection and R reflection . 8. The image display device according to claim 6, wherein said monochrome liquid crystal panel is a ferroelectric liquid crystal.