JPH04100088A - Direct viewing type picture display device - Google Patents

Abstract

PURPOSE:To prevent the occurrence of a speckle noise and to view an excellent image with a little power consumption by modulating a laser light beam with a video signal so that scanning may be performed and directly forming the image on the retina of eyes through an optical system. CONSTITUTION:The laser light beam emitted from an He-Ne laser 11 is con verged and made incident on an acoustooptical modulator AOM 13, then the intensity of the laser light is modulated with the signal of a video signal supply circuit 14. It is deflected at right angle by a reflection mirror 17. A filter 16 is a black filter. The cross-sectional shape of the beam is converted to an ellipti cal shape by cylindrical lenses 18, 19 and 20, made incident on an acoustooptical deflector AOD 21 and scanning is performed by a horizontal scanning signal supply circuit 22. Then, the cross-sectional shape of the beam is restored to be circular again by cylindrical lenses 23 and 24 and the plane of polarization in a vertical direction is converted to circular polarization of light by a #l/4 polarizing plate 25. A galvanometric mirror 26 is driven by a vertical scanning signal supply circuit 27 to perform vertical scanning, so that the light is directly made incident in the eye 28 through lenses 29 and 30.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a direct-view image display device that displays an image on the retina of the eye using laser light.

[Conventional technology]

Conventionally, image display devices using laser light have been used for projection, in which the laser light emitted from a light source or one light source is optically modulated by a video signal, horizontal scanning and vertical scanning are performed by a scanning system, and the image is projected onto a screen. There is a type image display device. The feature of this device is that it can obtain images with high brightness, high resolution, and high color purity.

[Problem to be solved by the invention]

However, in the above-mentioned image display device, since the surface of the screen is rough, there is a problem in that the projected laser light is diffused and flickers, resulting in so-called speckle noise.

The present invention has been made in view of the above points, and provides a good ii
! Reduce the amount of light and W! It is an object of the present invention to provide a direct-view type image display device that can be viewed without using electricity.

[Means to solve the problem]

The direct-view image display device of the present invention includes a light source that emits laser light, modulation means that modulates the laser light emitted from the light source using a video signal, and modulated laser light that uses a scanning signal to modulate the laser light. It is characterized by comprising a scanning means that performs horizontal scanning and vertical scanning, and an optical system that forms an image of the scanned laser light on the retina of the eye.

[Effect]

In the direct-view image display device having the above configuration, the light intensity is modulated by the modulation means, and the beam of light is scanned horizontally and vertically by the scanning means, and the beam is directly imaged on the retina of the eye by the optical system, and is directly visible as an image. can do.

Since this image is formed using laser light, it is possible to achieve high resolution with one-color purity. Also, since all the light is directed towards the eyes, high brightness can be obtained with a small amount of light. Furthermore, it is possible to prevent the occurrence of speckle noise seen in projection type image display devices using laser light.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a direct view type image display device according to the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of this embodiment, and FIG. 2 is an explanatory diagram showing the specific configuration of each part.

As shown in FIG. 1, the image display device according to this embodiment has a light source 1 using a semiconductor laser, a He-Ne laser, etc., and a video signal supplied from a video signal supply circuit 2, which emits light g1. An optical modulation system 3 as a modulation means for modulating the intensity of laser light, a scanning system 5 as a scanning means for horizontal scanning and vertical scanning of the modulated laser light by a scanning signal supplied from a scanning signal supplying means 4, a projection optical system 6 that forms an image of the laser beam directly onto the retina of the eye 7;
It consists of Note that when a semiconductor laser is used as the light source 1, the optical modulation system 3 can be integrated with the light source 1.

Next, with reference to FIG. 2, the specific structure and operation of each part will be explained. In the embodiment of FIG.

As the light source 1, a HeNe laser 11 is used.

Laser light emitted from the He-Ne laser 11 is converged by a convex lens 12 and enters an acousto-optic modulator (AOM) 13 used as an optical modulation system 3. AOM
13, the intensity of the incident laser light is modulated by the video signal input from the video signal supply circuit FIPt14 as the video signal supply means 2. The modulated laser light is
The convex lens 15 converts the light into parallel light, which is then filtered by a filter (ND-
F) 16 and hits the reflecting mirror 17, and the optical path is deflected approximately at right angles. Here, the filter 16 is a black filter, and has the effect of attenuating the intensity of light to a level that is not dangerous even if it enters the eyes.

The laser beam reflected by the reflecting mirror 17 is converted by cylindrical lenses 18, 19, 20 into an elliptical cross-sectional shape of the beam 11 suitable for entering an acousto-optic deflector (AOD) 21 as a horizontal scanning system. Ru. and,
The laser beam incident on the AOD 21 is transmitted to the scanning signal supply means 4
Horizontal scanning is performed in accordance with the horizontal scanning signal inputted from the horizontal scanning signal supply circuit 22 as shown in FIG. The horizontally scanned laser beam is returned to a beam shape with a circular cross section by the two cylindrical lenses 23 and 24, and the vertical plane of polarization is converted into circularly polarized light by the λ/4 polarizing plate 25 inserted between them. The circular beam-shaped laser beam converted into zero circularly polarized light enters a galvanometric mirror (GM) 26 as a vertical scanning system. 0M26 is driven by a vertical scanning signal inputted from an honest scanning signal supply circuit 27 as scanning signal supplying means 4, and performs vertical scanning of the laser beam.

The laser beam modulated and scanned as described above is transmitted to the eye 28.
through lenses 29° and 30 that constitute the optical system 6 for projection to flll! 28 (corresponding to eye 7 in FIG. 1). That is, by lens 29.

The laser beam once converged on the surface 31 passes through the lens 3o
After being converted into a parallel beam, the beam enters the eye 28 and is imaged on the retina 33 by the crystalline lens 32 of the eye 28 .

As shown in FIG. 3, the eye 28 focuses light rays emitted from a single point in the external space onto the retina 33 through the crystalline lens 32, stimulates the visual axis a34 in the retina 33, and forms an image as a collection of image points. In this embodiment, as shown in FIG. 4, the screen ff133 is scanned with a laser beam, and an image is perceived.

In this example, the amount of light entering the eye 28 was set to 1nw to 2nw, and a resolution of 300 TV lines to 350 TV lines could be obtained. In addition, the spot diameter of the laser beam in the pupil area was set at approximately 2.2 m+, but if this spot diameter becomes less than 1 m, the image becomes invisible due to movement of the pupil 50 or iris 51, so this diameter must be 11 w++ or more. Furthermore, the horizontal viewing angle was set to 8.8 degrees.

This viewing angle is 25cm wide when watching a 1.9-inch TV from a remote location. The larger the viewing angle, the more you are looking at a large screen.According to this preferred embodiment, since no screen is used, it is possible to remove speckle noise that can be seen in a projection type image display device. . Moreover, all the laser light is directed towards the eyes,
H that requires less light and emits laser light
The power consumed by the e-N e laser unit can be reduced. Furthermore, the image has features that can only be seen by the observer and are invisible to those around it.

FIG. 5 is a perspective view showing a configuration when the present invention is applied to a color image display device. In FIG. 5, parts corresponding to those in the embodiment shown in FIG. 2 are denoted by the same reference numerals, and a description thereof will be omitted for convenience.

In this embodiment, 1. Lasers IIR and IIG each emit three colors of laser light: red, green, and blue.

11B is installed, and AOM13R is installed in each of the nine optical paths.

13G, 13B, lenses 15R, 15G, 15B, and dichroic mirrors 41R, 41G, 41B were provided. The laser light emitted from each laser 11 is red and green at each AOM 13 in its respective optical path.

The light is modulated by each evening color signal. The modulated laser light is converted into a tree light beam 42 by a dichroic ink mirror 41 that reflects the light of each color and transmits the light of other colors.
After the rotation polygon mirror 43 as a horizontal scanning system
horizontally scanned by

The horizontally scanned laser beam is converted into parallel light 45 by a lens 44, and further focused by a lens 46 onto 0M26 as a vertical scanning system, and is vertically scanned.

The three-color laser beam 47 modulated and scanned in this way is
The light is incident on @28 through a lens 29.30 serving as a projection optical system of r@28.

According to this embodiment, the laser 11R911G with multiple wavelengths,
By using IIB, it becomes possible to display color images. These multiple wavelengths are not limited to three, but four.
It may be more than one, and increasing the number will widen the color reproduction range.

[Effects of the Invention] As explained above, the direct view type image display Viff of the present invention
According to , the laser beam is scanned by being modulated by a video signal, and the laser beam is directly imaged on the retina of the eye via an optical system.

It prevents speckle noise from occurring and allows you to see good images with less power consumption.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment of the direct view type image display device of the present invention, FIG. 2 is an explanatory diagram showing the detailed configuration of each part, and FIGS. FIG. 5 is a perspective view showing the structure of another embodiment of the direct view type image display device of the present invention. l...Light source, 2...Video signal supply means, 3...Modulation means (light modulation system), 4...Scanning number n supply means, 5
... Scanning means (scanning system), 6... Projection optical system, 7
···eye.

Claims (1)

[Scope of Claims] A light source that emits a laser beam; a modulator that optically modulates the light source or the laser beam emitted from the light source using a video signal; and horizontal scanning and scanning of the modulated laser beam using a scanning signal, respectively. 1. A direct-view image display device comprising: a scanning device that performs vertical scanning; and an optical system that forms an image of the scanned laser beam on the retina of the eye.