JPH06242726A - Display device - Google Patents

Abstract

PURPOSE: To provide a display device of excellent light emission efficiency. CONSTITUTION: An LCD element matrix 10 is arranged above an ultraviolet radiation source 2 and the array of lenses 30 provided on a radiation non- transmissive supporting body 31 is aligned and arranged between them. A light emitting body material 33 for emitting light in red, green or blue is provided on the lower surface of the lens 30. The lens 30 absorbs ultraviolet rays and an ultraviolet ray reflection layer 34 is provided on the upper side of the light emitting body material 33. The lens 30 focuses visible light from the light emitting body material 33 to an LCD element on the upper side and blocks the ultraviolet rays. By energizing the other one of the LCD element 10, this display device indicates other light emission.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is directed to a first matrix of a plurality of electrically activatable elements, each of which is individually activatable and capable of varying the amount of radiation passing through.
The present invention relates to a display device having an array, a radiation source located on one side of the display device, and an intermediate optical unit located between the first matrix array and the radiation source.

The present invention particularly relates to a multicolor matrix display device.

[0003]

BACKGROUND OF THE INVENTION Many methods are known for forming multicolored images by liquid crystal display (LCD) or other matrix display devices. As one of these, there is one in which white light is emitted from the back surface of the display device and each individual color filter is arranged in alignment with each individual element of the matrix. For example, activation of the element aligned with the red filter will result in a red image. The known device of this type has a drawback that the filter reduces the amount of light passing therethrough and reduces the luminous efficiency of the display device.

[0004]

OBJECT OF THE INVENTION The object of the invention is to obtain a display device which remedies the drawbacks of the known devices mentioned above.

In the display device of the present invention, the radiation source is an ultraviolet radiation source, and the intermediate optical unit includes a second matrix composed of an array of light emitting regions aligned with the first matrix. Different emission regions of the are composed of at least two different materials arranged to produce two different colors of visible light when illuminated by ultraviolet radiation from an ultraviolet radiation source, and further comprising a first matrix. And a second matrix having a third matrix of lens elements arranged between the second matrix and the third matrix of lens elements, the visible light emitted by the light emitting region being electrically of the first matrix. It is characterized in that it is arranged so as to focus on the element capable of being biased.

The light emitting region may be provided on the surface of the lens element, or may be provided on the surface of a plate provided between the lens element and the radiation source. The light emitting region is conveniently provided with a layer of UV-reflecting material provided on the surface remote from the radiation source. The display device may be provided with a support for the lens element. This support does not allow any radiation to pass except through the lens element. Display devices are mainly red, green,
It has a light emitting region that produces three different colors of blue. The electrically activatable element may be an LCD element. The lens element is a convex lens and is made of an ultraviolet absorbing material.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An example of a three-color LCD display device according to the present invention will be described with reference to the drawings.

In FIG. 1 and FIG. 2, this display device is L
It has a CD unit 1, an ultraviolet (external ray) light source 2, and an intermediate optical unit 3 arranged between the LCD unit 1 and the ultraviolet light source 2.

The LCD unit 1 is conventionally known and is normally transparent, but the address / energizing unit 11 is used.
It has a matrix array of pixels, namely components that can be opaque or partially opaque when applied with more voltage. Any one or more of the pixels (elements) 10 can be activated by appropriately selecting the x and y address electrodes for that element. Pixels can be addressed by known multiplexing techniques or by using active matrix addressing techniques such as in thin film diode or transistor switch pixels. In this way, an image can be represented by making some pixels opaque. These pixels are arranged in parallel rows and columns, and the pixels in adjacent rows are arranged in a so-called staggered arrangement in which the distance between the pixels is displaced by 1/2. Typically, each pixel has a width of about 0.12 mm, and L
The CD unit has 2048 × 2048 pixels.

The ultraviolet light source 2 is conventionally known and has a plurality of gas discharge tubes juxtaposed to each other. Alternatively, this light source may be, for example, WO 90/09676, GB 22
44855, GB 2247563, GB226132
Similar to a flat panel discharge lamp as described in No. 0, but without the emissive coating, the radiation emanating from the panel may be primarily in the ultraviolet region of the spectrum. Advantageously, the light source 2 is provided with a reflector 20 on its lower side so that the light is reflected upwards towards the LCD unit.

The intermediate optical unit 3 has a matrix array of focusing lenses 30 mounted on a support 31. The array of lenses is pixel 1 of LCD unit 1.
Each lens 30 is an LCD
Each element of the unit, that is, directly below the pixel 10 is aligned. Each lens is made of glass or plastic that absorbs UV radiation and is biconvex. Alternatively, an array of holographic lenses can be used. The lower curved surface 32 of each lens 30 is coated with a layer 34 that transmits visible light and reflects ultraviolet radiation. On the outside of this layer 34, a thick layer 33 of a luminescent material, for example phosphorus, is provided. Three different luminescent materials are used, one of which emits mainly red visible light and the other of which emits mainly green and blue light when exposed to UV radiation. As shown in the drawing, each pixel arranged along each row of the lens 30 is coated with a different color light emitting material, red / R, green / G, or blue / B. Various other forms or combinations are possible, for example, it is desirable to have more green emitting regions compared to red and blue in some arrangements. Lens 30
Is approximately the same as the diameter of the pixel 10 of the LCD unit.

The support 31 has a lower plate 35 made of plastic or glass which is transparent to ultraviolet rays.
Similarly, an upper plate 36 made of a plastic material or the like extends around the lens 30, and the plate 36 is provided with a hole 37 through which the lens 30 is projected. The upper plate 36 can also be made of a material such as glass that absorbs ultraviolet rays. A mask film 38 made of a material opaque to ultraviolet rays and visible rays is provided between the upper plate 36 and the lower plate 35. The mask film 38 may be composed of a mesh formed by etching glass or ceramic. The mask film 38 has an array of circular holes 39 aligned with the positions of the lenses 30, the mask extending between the lenses so that radiation other than passing through the lenses passes through the intermediate optical unit 3. Prevent.

In FIG. 1, the LCD unit 1, the ultraviolet light source 2 and the intermediate optical unit 3 are shown separated from each other. However, in order to make the structure even smaller, they are arranged in abutting contact with each other. You can also

When the apparatus is operated, the biasing unit 11 supplies a voltage to the LCD unit so that the pixels other than the pixels 30 which emit red, green or blue light are made opaque. Ultraviolet rays emitted from the light source 2 pass through the optical unit 3 to the upper side. The lower plate 35 slightly attenuates the radiation. This ultraviolet radiation is incident on the lower side of the light emitting coating 33 of the lens 30.
The layer thickness of the luminescent coating 33 is selected to provide maximum efficiency in multiple elastic collisions with the luminescent material before each photon of ultraviolet light is absorbed. Typically, the light emitting material layer 33 has a thickness of about 15 μm, and different light emitting materials emitting red, green and blue light are used. Visible light emitted from each light emitting material layer 33 is diffused in all directions, but a part thereof is incident on the lens 30 toward the upper side, and these are focused on the respective elements of the LCD unit 1 located on the upper side. .

Since the lenses 30 are made of a UV absorbing material, these lenses 30 prevent these UV rays from illuminating the LCD unit in the presence of UV radiation passing through the layer of luminescent material 33. ) Acts. Below each lens 30, the material of the UV-reflecting layer 34, which is provided between the lens and the light-emitting material layer 33, further reduces the amount of UV radiation emitted from the intermediate optical unit 3. This is because when the ultraviolet radiation is excessively long, the liquid crystal material is polymerized or crosslinked, and
Since the CD unit 1 is deteriorated, there is an advantage in preventing that point. Further, since the lens 30 is opaque to ultraviolet rays, the lower surface of the lens 30 becomes a reflection surface for ultraviolet rays passing through the light emitting material. The thus leaked ultraviolet rays return to the light emitting material, and further cause a light emitting phenomenon to increase the generation of visible light.

Each lens 30 produces a focused beam of red, green or blue light which is incident on the corresponding pixel 10 of the LCD unit 1. Pixels 10 that are opaque block the passage of light, and pixels 10 that are transparent pass red, green, or blue light. Different colors are formed by each combination of red, green, and blue. The size of the pixel is small enough that the colors merge when viewed from a certain distance,
It displays a color screen similar to a television screen with a color cathode ray tube.

In the present invention, since it is not necessary to use a filter, the light generated from the light emitting material can be utilized with maximum efficiency.
This effect can be multiplied by using an array of lenses. That is, a high level of passing radiation is added to each LCD pixel, and crosstalk between pixels is low. According to the present invention, it is possible to use an existing LCD display device in the related art, and it is not necessary to manufacture an LCD with a special material.

The invention is capable of many variants. For example, some display applications require only two different colored emitters. It is not an absolute requirement to coat the light emitting material on the lens itself, but it is also possible to coat the lower plate 35. This has the advantage of ease of operation that the light emitting material layer need only be deposited on a flat surface. FIG. 3 shows a situation in which the light emitting material layer 33 'is deposited on the flat surface of the intermediate optical unit 3'. In this arrangement, the lens 3
0'uses a glass microlens array marketed under the trade name smile by Corning Photofoam Glass. The lens 30 'is integrally formed within the thickness of the opaque glass substrate 36'. The lens array is spaced above the luminescent material layer 33 'deposited on the upper surface of the lower plate 35'. A layer 34 'of UV-reflecting coating is formed on the lower surface of the lens arrays 30', 36 'so that all UV light that has passed through the layer 33' of luminescent material is reflected towards the layer 33 'of luminescent material.

[Brief description of drawings]

FIG. 1 is a sectional view of a display device of the present invention,

FIG. 2 is a plan view of a display device of the present invention,

FIG. 3 is a cross-sectional view of essential parts of a modified example of the display device of the present invention.

[Explanation of symbols]

 1 LCD unit 2 Light source (ultraviolet radiation source) 3, 3'Optical unit 10 Pixel 11 Address / energizing unit 20 Reflector 30, 30 'Focusing lens 31 Support 32 Curved surface 33 Light emitting material layer 34, 34' Ultraviolet reflective layer 35, 35 'Lower plate 36 Upper plate 37 Hole 38 Masking film 39 Hole 36' Substrate

Claims (9)

[Claims] 1. A first matrix array of a plurality of electrically activatable elements, each individually activatable and capable of varying the amount of radiation passing therethrough, on one side of a display device. A display device comprising a positioned radiation source and an intermediate optical unit positioned between the first matrix array and the radiation source, wherein the radiation source is an ultraviolet radiation source (2). The unit is the first matrix (1
0) and a second matrix consisting of an array of light emitting areas (33, 33 ') aligned with each other, the different ones of these light emitting areas (33, 33') being the ultraviolet radiation source (2).
Comprised of at least two different materials arranged to produce two different colors of visible light when illuminated by more ultraviolet light, and further arranged between a first matrix and a second matrix The third matrix of lens elements (30, 30 ') is arranged, and the third matrix of lens elements (30, 30') is provided.
30 ') is arranged such that the visible light emitted by said light emitting area (33, 33') is focused towards the electrically activatable element (10) of the first matrix. Characteristic display device. 2. The display device according to claim 1, wherein the light emitting region (33) is formed on the surface of the lens element (30). 3. A display device according to claim 1, wherein the light emitting area (33 ') is formed on the surface of a plate (35') located between the lens element (30 ') and the radiation source (2). Display device. 4. The display device according to claim 1, wherein the light emitting region (33, 33 ′) is made of an ultraviolet reflecting material provided on a surface farther from the ultraviolet radiation source (2). A display device having a layer (34). 5. The display device according to claim 1, wherein the display device has supports (31, 35, 36, 38) for the lens element (30), and these supports are provided. A display device that blocks radiation other than radiation that passes through the lens element so that the radiation does not pass therethrough. 6. The display device according to claim 1, wherein the display device is provided with three different light emitting regions (3) which mainly emit light of three different colors of red, green and blue.
3, 33 '). 7. The display device according to claim 1, wherein the electrically actuatable element (10) is L.
A display device using a CD element. 8. The display device according to claim 1, wherein the lens element is a convex lens. 9. The display device according to claim 1, wherein the lens element (30, 30 ′) is made of an ultraviolet radiation absorbing material.