JPH01116628A - Active screen - Google Patents

Abstract

PURPOSE:To view a distinct projected image in environment such as a normally lighted room by providing an optical transmission layer where resistance distribution corresponding to the intensity distribution of image information light is generated and a liquid crystal layer having a memory action on which a voltage is impressed corresponding to the resistance distribution of the optical transmission layer. CONSTITUTION:The title screen is constituted of two glass substrates 10 and 18 made of transparent glass, transparent electrodes 11, 15 and 17 arranged between the glass substrates 10 and 18, the optical transmission layer 12, an optical absorption layer 13, a reflection layer 14 and a liquid crystal layer 16. When the specified voltage is impressed on the transparent electrodes 11 and 17 and the image such as a slide, etc., is projected from a projector 26 onto the surface of an active screen 1 on the transparent glass 10 side, the resistance distribution corresponding to the intensity distribution of the projected light is generated on the optical transmission layer 12. Even if the impressing the voltage and the image information light given to the optical transmission layer 12 is interrupted, the image corresponding to the image information light is stored in the liquid crystal layer 16. Thus, the distinct projected image can be viewed in the normally lighted room.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an active type screen (hereinafter referred to as an active screen) capable of projecting a projected image in a bright room.

[Conventional technology]

A conventional screen is a white screen made of cloth with white paint sprayed on it.An image is projected from a projector onto this white area, and the image reflected on this white background is viewed in a nearly completely dark room. It was something to do. In addition, recently, special treatments such as cloth coated with highly reflective metal particles or glass have become available, making it possible to view them even in slightly bright rooms.

[Problem that the invention seeks to solve]

However, not only with the above-mentioned white curtain but also with a specially processed screen, it is not possible to view a clear projected image in a room with normal brightness without reducing the amount of indoor light.

Furthermore, if the same image is to be displayed on the screen for a long period of time, there is a problem in that the halogen lamp built into the projector must be kept on for a long period of time.

[Purpose of the invention]

The present invention was made in order to solve the above-mentioned problems, and it is possible to enjoy a clear projected image in a room with normal brightness without reducing the amount of indoor light. It is an object of the present invention to provide an active screen that actively creates an image according to the light intensity of a projected image so that display can be easily performed.

[Means for solving problems]

In order to achieve the above object, the active screen of the present invention includes a photoconductive layer (photoconductor) that generates a resistance distribution corresponding to the intensity distribution of the given image information light, and a photoconductor that generates a resistance distribution corresponding to the intensity distribution of the given image information light. It consists of a liquid crystal layer having a memory function to which a voltage is applied, two transparent electrodes sandwiching this liquid crystal layer and the photoconductive layer, and a power source connected to the transparent electrode, and a voltage is applied by the power source. Even if the image information light applied to the photoconductive layer is interrupted, an image corresponding to the image information light is stored in the liquid crystal layer.

[Effect]

According to the above configuration, the active screen of the present invention can be set in a normal bright room and the power can be turned on to the active screen without making troublesome preparations such as closing windows and doors and turning off indoor lights. If you project an image from a projector, you can immediately enjoy a clear projected image in a bright room. In addition, since the liquid crystal uses a memory function, even if the desired image is projected onto the active screen and the active screen is turned off or image projection is interrupted, the image will be erased. The same image will continue to be displayed as long as no operation is performed. I can do it.

Embodiments of the present invention will be described in detail below with reference to the drawings.

〔Example〕

In FIG. 1 showing an embodiment of the active screen 1 of the present invention, the active screen 1 includes two glass substrates io and ts made of transparent glass, and a transparent electrode 11 disposed between these glass substrates 10 and 18. .15.1?
, Photo Conductor RPjA
12. Light absorbing N131 reflective layer 14. It consists of a liquid crystal layer 16. The transparent electrode 11.17 is a glass substrate 10.18.
The transparent electrode 15 is coated on the inside of each of the reflective Ji! 14 is covered.

A minute R (red) filter 20. is provided on the outer surface of each of the glass substrates 10.18. G (green) filter 21.
A filter group including B (blue) filter 22, and R
Filter 23. A group of filters including a G filter 24 and a B filter 25 are pasted on one side in correspondence with each other.

The light absorption layer 139 reflective layer 14 is the light conductive layer 7112.
and the liquid crystal layer 16. The photoconductive layer 1
In No. 2, a CdS deposited layer with a thickness of 2 to 12 μm is used, and the liquid crystal used for the liquid crystal layer 16 is a ferroelectric smectic liquid crystal having a memory function. here,
The resistance per unit area of the liquid crystal layer 16 RLC is the resistance per unit area of the photoconductive layer 12 with and without light irradiation, that is, the bright resistance R0N and the dark resistance ROFF.
OFy) RLC) ROM.

The reflective layer 14 has ZnS/MgF! for reflecting the illumination light emitted from the illumination light source 27. In the multilayer reflective film, the light absorption layer 13 is a 2 μm thick CdTe layer and is provided to absorb illumination light that has passed through the reflection N14 and prevent it from entering the photoconductive layer 12. Moreover, the transparent electrode 11. A power supply 30 and a switch 32 that apply a DC voltage are connected to L7, and the transparent electrode 15
．． 17 is connected to a power source 31 and a switch 33. The transparent electrode 15 is provided to erase the image stored in the liquid crystal layer 16, and the transparent electrode 15.17
The voltage applied to the transparent electrode 11.17 is of opposite polarity to the voltage applied to the transparent electrode 11.17.

To use the active screen 1 having such a structure, first turn on the switch 32 and connect the transparent electrodes 11.
A predetermined voltage is applied to 17. When an image of a slide or the like is projected from the projector 26 onto the transparent glass 10 side of the active screen 1, a resistance distribution corresponding to the intensity distribution of the projected light is generated in the photoconductive layer 12.

For example, to explain the projection light that has passed through one R filter 20, the projection light that has passed through this R filter 20 is only the red component of one minute point in the projection light, and After passing through the filter 20, the glass substrate 10.
The light passes through the transparent electrode 11 and enters the photoconductor jW12.

Depending on the brightness of the red component light incident on the photoconductive layer 12,
°, the resistance value of the photoconductive layer 12 at the position corresponding to the R filter 20 decreases. A voltage corresponding to the amount of drop in the resistance value is applied from the transparent electrode 11.17 to the liquid crystal layer 16 at a position corresponding to the R filter 20, and the molecular arrangement changes due to the electro-optic effect.

On the other hand, since the R filter 23 is attached to the glass substrate 18 at a position corresponding to the R filter 20, the liquid crystal layer 16 at the position corresponding to the above-mentioned R filter 20 from the 1st side of the glass substrate passes through the R filter 23. observed. As a result, the red component of the projection light is formed as a corresponding red component liquid crystal image on the glass substrate 18 side. Note that the glass substrate 18 side is irradiated with illumination light from an illumination light source 27, this illumination light is reflected by the reflective layer 14, and the liquid crystal image is observed in a reflective manner.

The other green and blue components are formed in the same way, and one pixel is formed by these three color components. By forming these pixels at high density over the entire surface of the glass substrate 1 side of the active screen 1, an image corresponding to the image projected from the projector 26 is formed on the glass substrate 18 side.

Here, since the liquid crystal layer 16 is a smectic liquid crystal layer having a memory function, even if the switch 32 is turned off or projection is stopped, the image formed on the liquid crystal 1!16 will not be lost and will be saved. Ru. Further, in order to erase the stored image, the erase switch 33 is turned on. As a result, a reverse voltage is applied between the transparent electrodes 15 and 17, the molecular alignment state of the liquid crystal layer 16 is returned to the initial state, and the stored image is erased.

Next, an application example in which the active screen 1 of the present invention is used as a document surface of a document projector to project an image onto a large screen is shown in FIGS. 2 and 3. In FIG. 2 showing the first application example, a lens 4 is placed in front of the reflective active screen 1 on which images are to be projected and stored as described above.
0. Mirror 41, lens 42. An illumination system consisting of a light source 43 is arranged. The white light emitted from the light source 43 is
The light is focused by a lens 42 and directed toward a mirror 41. mirror 4
The light reflected by 1 is irradiated by a lens 40 onto a liquid crystal image layer in which an image is stored in advance.

The illuminated stored image is focused onto the surface of the screen 50 by the lens 40 . Incidentally, in order to store an image on the active screen 1, the original may be temporarily placed in a part of the illumination system and the image may be formed on the active screen 1.

Further, the mirror 41 of the illumination system. Lens 42. light source 43
The part consisting of is an overhead projector (OHP)
may be used.

In FIG. 3 showing a second application example, the active screen 2 is not the above-mentioned reflective type active screen, but is a transmissive type active screen in which the reflective layer 14 and the light absorption layer 13 are removed from the active screen 1. Behind this active screen 2 is a lens 44. An illumination system consisting of a light source 45 is installed, and a lens 46 is placed in front. First, turn off the power to the active screen 2 so that the stored image will not be erased when exposed to light.
Set it to FF and turn on the light source 45. light source 45
The white light emitted from the lens 44 is irradiated onto the photoconductive layer side, illuminating the liquid crystal layer in which the image is stored from behind. The image light of the illuminated liquid crystal layer is imaged onto the surface of the screen 50 by a lens 46 disposed in front. Note that in order to store an image on the active screen 2, the document may be temporarily placed in a part of the illumination system, as in the first application example.

Note that if the full-color filter is removed from the active screen 1, it becomes a high-resolution monochrome active screen that faithfully reproduces the brightness of the projected image. Further, by making the active screen 1 of the present invention ultra-small, it can be applied as a camera display or as an auxiliary confirmation means during exposure. For example, the active screen of the present invention is installed in an exposure chamber of a single-lens camera, and a subject image incident from a photographic lens is guided to this active screen via a sub-mirror or the like. Then, by storing the subject image on an active screen in conjunction with the shutter opening, and displaying this on a display device such as an external screen, you can capture the subject image at the time of shooting without having to wait for the film to be developed. It becomes possible to check the image.

〔Effect of the invention〕

As described above, according to the active screen of the present invention,
Since a phototransfer mF3 that generates a resistance distribution corresponding to the intensity distribution of image information light and a liquid crystal layer having a memory function to which a voltage is applied in accordance with the resistance distribution of this photoconductive layer are provided,
You can enjoy clear projected images in the comfort of a normal bright room without having to make the troublesome preparations that you would with a normal screen, such as closing the windows and doors, turning off the room lights, and darkening the room. You will be able to do this. In addition, an image displayed at -degrees will continue to be displayed unless it is deleted, so if you want to display the same image for a long time, you can easily display it for a long time. can.

It becomes like this. If this characteristic is utilized, it can be used for projection original surfaces such as OHP, and furthermore, by making it smaller, it can also be used as a simple portable image storage device. Furthermore, if applied to a single-lens camera, it would be possible to store the image at the moment the shutter was released and check the image at the time of exposure.

[Brief explanation of the drawing]

FIG. 1 is a side sectional view of one embodiment of the present invention. FIG. 2 is a schematic diagram showing a first application example of an embodiment of the present invention. FIG. 3 is a schematic diagram showing a second application example of an embodiment of the present invention. 1.2...Active screen 10.18...Glass substrate 11, . 15.17...Transparent electrode 12...Photoconductive layer 14...Reflection layer 16...Liquid crystal layer 30.31...Power source.

Claims (5)

[Claims] (1) A photoconductive layer that generates a resistance distribution corresponding to the intensity distribution of the given image information light, a liquid crystal layer that has a memory function to which a voltage is applied in accordance with the resistance distribution of this photoconductive layer, and this liquid crystal layer. and the photoconductive layer, and a power supply connected to the transparent electrodes, and even if the voltage application by the power supply and the image information light applied to the photoconductive layer are interrupted, the An active screen characterized in that an image corresponding to image information light is stored in the liquid crystal layer. (2) The active screen according to claim 1, wherein a reflective film is provided between the photoconductive layer and the liquid crystal layer. (3) A claim characterized in that glass substrates are provided to support the transparent electrodes from the outside, and R, G, and B filters are respectively arranged at opposing positions on the outer surfaces of the two glass substrates. The active screen described in item 1. (4) The active screen according to claim 1, wherein the liquid crystal layer is provided with a power source and wiring for erasing a memory image. (5) The active screen according to claim 1, wherein the active screen is installed on a projection document surface of an image projector.