JP2001324936A - Color display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a color display device with improved productivity and improved picture quality. SOLUTION: The display device is equipped with a plasma display device 12 for black-and-white display having a flat front glass and using phosphors for red, green and blue colors as a mixed phosphor. The mixed phosphor 14 is prepared by mixing phosphors of red, green and blue colors in a molar ratio inversely proportional to the light emission efficiency. A region where the mixture phosphor 14 is to be applied is formed in each pixel, and a barrier rib 15 is formed between regions of the mixture phosphor 14. Operation of a liquid crystal color shutter 16 is synchronized with the illumination light of the plasma display device 12 to transmit the individual wavelengths so that repeated images of red, green and blue colors can be obtained in each pixel according to the luminance. By operating the system plane-sequentially and continuously, the colors of the image are visually mixed with time to display an image recognized as a color image.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a color display device for obtaining a color image by a frame sequential method using a plasma display device.

[0002]

2. Description of the Related Art In recent years, a plasma display device has been used as a thin display as a color display device. In a color display device using a conventional plasma display device, a light-emitting region is separated into red, green, and blue, and each color emits light to spatially mix colors to perform color display.

As shown in FIG. 4, in a conventional color display device using a plasma display, a red (R) phosphor 2 and a green (G) color are provided for one pixel in a plasma display device 1. The phosphor 3 and the blue (B) phosphor 4 are applied to the respective regions, and the red phosphor 2, the green phosphor 3, and the blue phosphor 4 are each provided between any of the regions. The partition walls 5 are provided so that the generated plasma does not spread to other regions.

However, in the method of spatially mixing colors, the partition 5 must be formed.
Is complicated and difficult for the fabrication of the plasma display device 1. In addition, the formation of the partition walls 5 increases the non-light-emitting area. In particular, when the number of pixels is increased for high-density display, the number of the partition walls 5 increases, and the non-light-emitting area further increases. Becomes very difficult to see. Further, the plasma display device 1
Since the luminous efficiency depends on the discharge space, if the discharge space becomes narrow due to the increase in the partition walls 5, the luminous efficiency decreases.

On the other hand, as another color display apparatus of the frame sequential type, a method is used in which a color polarizing film and a color shutter having a liquid crystal cell are attached to a front glass of a black and white cathode ray tube (CRT).

[0006] However, it is extremely difficult to attach a color shutter to the front glass of a cathode ray tube in a curved manner. Usually, a flat color shutter is arranged on the front surface, but a space is inevitably generated and transmitted light is inevitably generated. However, there is a problem that the number of particles is reduced by scattering.

[0007]

As described above, in the method of spatially mixing colors, the partition walls 5 must be formed without fail, which complicates the manufacture and increases the non-light-emitting area and the area of the non-display surface. As the ratio increases, a clear image cannot be obtained, making it extremely difficult to see. Furthermore, the discharge space is narrowed by the partition walls 5, and the luminous efficiency is reduced.

In the method of attaching a color shutter to the front glass of a cathode ray tube, it is extremely difficult to curve and attach the color shutter to the front glass of the cathode ray tube. There is a problem that it is reduced by scattering.

In view of the above problems, the present invention does not require the formation of a partition as in the prior art, and as a result, provides a color plasma display which is excellent in luminous efficiency, can obtain clear image quality, and is excellent in productivity. The goal is to do things.
The present invention has been made in view of the above problems, and an object of the present invention is to provide a color display device having improved manufacturability and improved image quality.

[0010]

SUMMARY OF THE INVENTION The present invention comprises a plasma display device for displaying black and white, and a color shutter disposed on the front of the plasma display device and emitting blue, green and red light in a sequential manner. Since it is not necessary to spatially mix red, green, and blue, the number of partitions can be reduced, so that productivity can be improved. In addition, since the front surface of the plasma display is flat, a color shutter can be formed without any space in front of the plasma display. Since the color shutter is attached, scattering of transmitted light is reduced, and the image quality is improved.

Further, the plasma display device has a front glass, and a color shutter is directly attached to the front glass. Since a space is hardly generated between the front glass and the color shutter, the image quality is improved. improves.

Further, the color shutter is provided with three types of color polarizers in which a dichroic dye is impregnated in a polymer film, and two liquid crystal cells.

Further, two types of color shutters are obtained by impregnating and aligning a dichroic dye, and the other type is a type of three color polarizers in which a number of retardation films are laminated.
And two liquid crystal cells.

In the plasma display device, a phosphor for red, a phosphor for green, and a phosphor for blue are mixed and applied in such a manner that the mixing molar ratio is inversely proportional to the luminous efficiency. To ensure.

The phosphor for red is (Y, Gd) BO.
₃ : Eu, the phosphor for green is ZnSiO ₄ : Mn, and the phosphor for blue is BaMgAl ₁₄ O ₂₃ : Eu.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the color display device of the present invention will be described below with reference to the drawings.

The color display device 11 shown in FIGS.
Has a flat front glass and (Y, Gd) BO ₃ :
A black-and-white plasma display using Eu as a phosphor for red (R), ZnSiO ₄ : Mn as a phosphor for green (G), and BaMgAl ₁₄ O ₂₃ : Eu as a phosphor for blue (B). An apparatus 12 is provided. In addition, the phosphor for red,
The mixed phosphor 14 is formed by mixing the phosphor for green and the phosphor for blue in a mixing molar ratio in inverse proportion to the luminous efficiency,
As shown in FIG. 3, a region to which the mixed phosphor 14 is applied is formed for each pixel, and a plasma generated by the mixed phosphor 14 in a certain region is mixed between the mixed phosphors 14 in another region. A rib-shaped partition wall 15 for preventing the phosphor 14 from being affected is formed. Then, a liquid crystal color shutter 16 is directly adhered to the front glass of this plasma display,
The image quality is improved by eliminating space and preventing scattering of transmitted light.

As shown in FIGS. 1 and 2, a liquid crystal color shutter 16 is provided with a red polarizing filter 17 as a red polarizing plate that transmits red, which is a first color polarizing plate, from the plasma display device 12 side. A first liquid crystal cell 18, a green polarizing filter 19 as a green polarizing plate that transmits green, which is a second color polarizing plate, a second liquid crystal cell 20, and a third
A blue polarizing filter 21 as a blue polarizing plate that transmits blue, which is a color polarizing plate, is formed by sequentially adhering each other with an adhesive that transmits light. The red polarizing filter 17, the green polarizing filter 19, and the blue polarizing filter 21 may be all three types of color polarizing plates in which a dichroic dye is impregnated in a polymer film, or two types may be two types. The other one that is impregnated with a coloring dye
The type may be a laminate of many retardation films.

Further, an image processing circuit 22 for processing an input image is connected to the plasma display device 12. The image processing circuit 22 and the liquid crystal color shutter 16 include a first liquid crystal cell 18 and a second liquid crystal cell.
A liquid crystal cell drive circuit 23 for driving the liquid crystal display 20 is connected.

The red polarization filter 17, the green polarization filter 19 and the blue polarization filter 21 have a transmission axis for transmitting white light and an absorption axis for transmitting only one of red, green and blue. I have.

The first liquid crystal cell 18 and the second liquid crystal cell 20 use the birefringence of the liquid crystal and apply a predetermined voltage, that is, on, or no application, that is, off, so that the red polarizing filter 17 and the green The operation of rotating the light transmitted through the polarization filter 19 and the blue polarization filter 21 by 90 degrees or transmitting the light as it is is repeated. These operations can be expressed as shown in Table 1, and finally pass through the red polarizing filter 17, the first liquid crystal cell 18, the green polarizing filter 19, the second liquid crystal cell 20, and the blue polarizing filter 21. After that, only the red, green and blue wavelengths are transmitted. As a result, a full-color image is projected on the front surface of the liquid crystal color shutter 16.

[0022]

[Table 1] Further, the plasma display device 12 is configured to output the first video signal.
During the field period, the luminance signal for red, the luminance signal for green, and the luminance signal for blue accompanying the video signal from the image processing circuit 22 are received in time series, and white light is emitted to the liquid crystal color shutter 16 in each period. .

Next, the operation of the embodiment will be described.

First, the plasma display device 12 emits white light, and during one field period of a video signal, the image processing circuit 22 outputs a red luminance signal, a green luminance signal, and a blue luminance signal accompanying the video signal. And the liquid crystal color shutter 16 is irradiated with white light in each period.

In addition, the liquid crystal color shutter 16 synchronizes with the period during which white light is radiated by the luminance signal for red, the red polarizing filter 17, the first liquid crystal cell 18, the green polarizing filter 19, and the second polarizing filter. Liquid crystal cell 20 and blue polarizing filter
Red light is selectively transmitted by the on / off operation of 21.

Similarly, blue is selected during a period when white light is radiated by a blue luminance signal, and green is selectively transmitted during a period when white light is radiated by a green luminance signal.

As described above, the operation of the liquid crystal color shutter 16 is synchronized with the irradiation light of the plasma display device 12 to transmit each wavelength, thereby allowing the liquid crystal color shutter to be transmitted.
From 16 it is possible to obtain red, green and blue repeated images for each pixel corresponding to each luminance, and display images recognized as color images by temporally mixing colors as viewing angles by continuous operation in a frame-sequential manner I do.

According to the above-described embodiment, the plasma display device 12 has only to form the partition 15 for each pixel as shown in FIG. 3, and the conventional red phosphor 2 and green phosphor shown in FIG. The partition 15 is reduced to 1/3 and the area of the non-display surface, which is a non-light-emitting area, is reduced to 1/3 and becomes clearer and brighter than that in which the partition 5 is formed between each of the phosphors 3 and the blue phosphor 4. Visibility can be improved.

According to the experiment, since the discharge volume of the plasma was increased three times or more, the luminous efficiency was confirmed to be improved by 50% or more.

Further, by adjusting the mixing molar ratio of the red phosphor, the green phosphor and the blue phosphor so as to be inversely proportional to the respective luminous efficiencies, the luminance of red, green and blue in the case of color display is obtained. When the phosphor was made to emit light, a predetermined color display could be realized.

[0031]

According to the present invention, the manufacturability is improved, and the color shutter is mounted without any space on the front surface of the plasma display because the front surface of the plasma display is flat. Image scattering can be reduced, and the image quality can be improved.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a state of a color display device according to an embodiment of the present invention from the side.

FIG. 2 is an explanatory diagram showing a color shutter according to the first embodiment;

FIG. 3 is an explanatory diagram showing a display surface of the plasma display.

FIG. 4 is an explanatory view showing a display surface of a conventional plasma display.

[Explanation of symbols]

 11 Color display device 12 Plasma display device 16 Color shutter 17 Red polarizing filter as color polarizing plate 18 First liquid crystal cell 19 Green polarizing filter as color polarizing plate 20 Second liquid crystal cell 21 Blue polarizing filter as color polarizing plate

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G09F 9/46 G09F 9/46 Z F-term (Reference) 2H088 EA40 HA15 HA19 MA20 2H089 HA28 HA31 QA16 TA14 TA15 UA09 2H091 FA09X FA09Z FA11X FA11Z FD06 FD10 LA15 MA10 5C094 AA08 AA10 AA43 BA15 BA31 BA32 BA43 CA19 CA24 DA03 DA12 EA04 EB02 ED03 ED14 FA01 FA02 FB20 GA10 5G435 AA03 AA04 AA17 BB06 HB12 BB15 CC09 CC12

Claims (6)

[Claims] 1. A color display device comprising: a plasma display device for displaying black and white; and a color shutter disposed on a front surface of the plasma display device and emitting blue, green, and red light in sequence. 2. The color display device according to claim 1, wherein the plasma display device has a front glass, and a color shutter is directly attached to the front glass. 3. A color shutter, wherein a dichroic dye is impregnated and oriented in a polymer film.
The color display device according to claim 1, further comprising: two types of color polarizing plates; and two liquid crystal cells. 4. A color shutter comprising two kinds of liquid crystal cells, two kinds of which have been impregnated with dichroic dyes, and the other kind has three kinds of color polarizers in which a number of retardation films are laminated, and two liquid crystal cells. The color display device according to claim 1, wherein the color display device is provided. 5. The plasma display device according to claim 1, wherein a phosphor for red, a phosphor for green and a phosphor for blue are mixed and applied in such a manner that a mixing molar ratio is inversely proportional to luminous efficiency. 5. The color display device according to any one of items 1 to 4. 6. The phosphor for red is (Y, Gd) BO ₃ : E.
6. The color display device according to claim 5, wherein u is a phosphor for green, ZnSiO ₄ : Mn, and a phosphor for blue is BaMgAl ₁₄ O ₂₃ : Eu.