Light-modulating element, display element, and exposure element

Abstract

Subjects for the invention are to provide a light-modulating element having an elevated energy efficiency while preventing a decrease in contrast at low cost without using a display technique employing a waveguide or lightguide plate, and to provide a display element capable of producing high-quality display images and an exposure element capable of exposure treatment.

Description

CROSS-REFERENCE TO RELATED APPLICATION [0001] This is a Divisional Application of pending prior U.S. application Ser. No. 10 / 484,151, which was the National Stage of International Application No. PCT / JP02 / 0614, filed Jun. 17, 2002, the disclosures of which are incorporated herein by reference.TECHNICAL FIELD [0002] The present invention relates to a flat light-modulating element and display element into which planar incident light is introduced to produce a desired image, and also to an exposure element. BACKGROUND ART [0003] Among devices in which incident light is regulated with respect to amplitude (intensity), phase, direction of traveling, or the like to process / exhibit an image or patterned data is a light-modulating element. In a light-modulating element, the refractive index of a substance which transmits light is changed by means of an external field applied to the substance and the intensity of the light which finally passes through or is reflected by this substance is con...

AI Technical Summary

Benefits of technology

[0027] In this light-modulating element, since the light to be introduced into the light-modulating element is planar light, the loss in a light path is reduced and the planar incident light can be introduced into the light-modulating element at a high efficiency while retaining the planar state. A constitution having an elevated energy efficiency can hence be attained.

[0145] In this display element, since a reflector has been disposed so as to face the incident-light introduction side of the display element, the incident light which has been injected into the display element and then reflected by the display element strikes on the reflector and the reflected light from this reflector is directed again toward the display element. Consequently, light recycling occurs and the efficiency of light utilization is improved. Thus, a higher efficiency is attained.

Problems solved by technology

However, the existing flat display elements described above have the following problems.

First, the liquid-crystal display has a problem that since the light emitted by the backlight is caused to pass through many layers comprising the polarizers, transparent electrodes, and color filter, the efficiency of light utilization is low.

Other problems thereof include those characteristic of liquid crystals, i.e., deterioration in image quality due to viewing angle dependence and deterioration in dynamic-image quality due to a low response rate, and a cost problem in large displays employing a TFT.

The plasma display has drawbacks that since partition walls for discharge should be formed for each pixel, it is difficult to obtain high brightness at a high efficiency when the resolution is high, and that the display is costly because it necessitates a high operating voltage.

Furthermore, the FED has a drawback that the production cost is high as in the plasma display because the inside of the panels should be evacuated to an ultrahigh vacuum so as to enable a discharge to occur stably at a high efficiency.

The FED has further had a disadvantage that a high voltage is necessary for accelerating electrons resulting from field emission and causing these to strike on the phosphor.

Furthermore, since the positional change with voltage shows hysteresis, passive-matrix operation with high contrast is possible in a two-dimensional array constitution and an active element such as TFT is unnecessary.

However, the lightguide plate / waveguide of a thin flat shape has a small edge area available for incidence and tends to have an impaired efficiency of coupling with incident light.

Moreover, since a further thickness reduction and a larger area are desired in lightguide plates and waveguides, the edge area available for incidence tends to decrease more and more and there is a fear of an impaired efficiency of coupling.

Furthermore, there are limitations on the shape of incident light (light source) and on position for introduction.

Namely, the size and number of light sources are limited and high-output light cannot be introduced.

In addition, the incident light should have a beam / linear shape and this poses limitations on the kind of light sources or separately necessitates an optical system for forming such shape.

As a result, there is a problem that the production process is complicated to increase the cost.

In the flat display element 80, when an element located upstream in the light path from the lightguide is brought into an ON state for image production, the light introduced into areas located downstream in the light path from this element attenuates to cause the so-called crosstalk and thereby impair image quality.

Furthermore, there also is a problem that leakage light released from an ON-state element reduces the contrast of images around the element.

On the other hand, in the flat display element 90, since high-output light is injected into the thin lightguide, a loss of light coupling occurs in the lightguide, resulting in a reduced efficiency of light utilization.

Furthermore, in case where the waveguide has even a slight defect in part thereof, leakage light is released from this part.

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