KR20060086058A - Projection-type image display system - Google Patents

Abstract

According to the present invention, a liquid crystal display panel having a current response speed is arranged to overlap each other in response to R / G / B color light and vibrated to cross each other so that the resolution of the image is improved by the effect of four times of pixel shaking. The present invention relates to a resolution correction apparatus for a projection image display system.

Preferably, the resolution correcting apparatus includes two liquid crystal display panels in which R / G / B color light arrives and are superimposed on each color, and each liquid crystal display panel is vibrated to vibrate the overlapped liquid crystal display panel. Means are connected, the vibrating means driving unit outputs a liquid crystal vibration control signal for vibrating the liquid crystal display panel by the vibrating means, the two liquid crystal display panels corresponding to the R / G / B color cross-vibration mutually When the two liquid crystal display panels vibrate mutually for each color, the resolution of the screen is improved by the effect of shaking the pixel four times.

Description

Resolution Correction Device for Projection Image Display System {PROJECTION-TYPE IMAGE DISPLAY SYSTEM}

1 is a view schematically showing the structure of a transmissive liquid crystal display device provided in a projection image display system;

FIG. 2 is a view showing the configuration of a projection type image display system to which the transmissive liquid crystal display device shown in FIG. 1 is applied as a liquid crystal display panel;

3 is a view for explaining an aperture ratio of one pixel of a liquid crystal display element employed in the projection image display system shown in FIG. 2;

4 is a diagram illustrating an example for resolution correction in the projection image display system illustrated in FIG. 2;

5A and 5B are diagrams for explaining resolution corrected screen display principles and display examples thereof in the projection image display system shown in FIG. 4;

6A and 6B are diagrams corresponding to FIGS. 5A and 5B for explaining the principle of display resolution and a display example thereof for improving the resolution in a projection type image display system employing a liquid crystal display device;

7 is a view showing a resolution correction apparatus of a projection type liquid crystal display system according to an embodiment of the present invention;                 

8A and 8B are views referred to for explaining the operation of the resolution correction apparatus of the projection type liquid crystal display system according to the preferred embodiment of the present invention shown in FIG.

* Description of the symbols for the main parts of the drawings *

10: liquid crystal display element 16: TFT section

20: liquid crystal layer 36: light source

52, 58, 70: first, second, third liquid crystal display panel

52a, 52b, 58a, 58b, 70a, 70b: liquid crystal display panel

72: dichroic prism 74: projection lens unit

80: color selection device 82: color switch

84: calcite 100: vibrating means (VCM) drive unit

102,104,106,108,110,112: vibration means (VCM)

The present invention relates to a resolution correction apparatus of a projection type image display system employing a transmissive liquid crystal, and more particularly, to a resolution correction apparatus of a projection type liquid crystal display system for projecting on a screen with an improved resolution of an image. .

Currently, a large screen image display system for enlarging and projecting original image information into a large screen typically includes a direct-view liquid crystal display, a plasma display, a projection television, a projector, and the like.

Among them, projection televisions and projectors are commonly equipped with an 'optical engine', and the optical engine is a CRT (Cathode Ray Tube) and LCD () as an image display device for visually displaying appropriately processed image information. Liquid Crystal display (DMD) and Digital Micro-mirror Device (DMD) are optionally used.

Recently, the development of a projection type image display system using a liquid crystal display device is attracting attention due to the unique advantages of liquid crystals. FIG. 1 shows a cross-sectional view of a transmissive liquid crystal display device.

Referring to the drawing, in the liquid crystal display device shown at 10, a first substrate (lower substrate) 12 and a second substrate (upper substrate) 14 made of glass are disposed on the lower side and the upper side thereof. A thin film transistor (TFT) unit 16 for driving the corresponding liquid crystal display device 10 is formed at a predetermined position on the first substrate 12 and a data storage capacitor for accumulating image data. A portion 18 is formed.

In addition, a liquid crystal layer 20 is defined between the first and second substrates 12 and 14 to adjust the amount of light transmitted by driving the TFT unit 14 in response to an electrical signal corresponding to an image. The second substrate (upper substrate) 14 defines a color filter 22 for realizing a color image, and a black matrix 24 on the side thereof.

A common electrode 24 by ITO is patterned under the color filter 22 and the black matrix 24, and a polarizing film or a polarizer is formed on the upper surface of the second substrate 28. ) 28 is formed.                         

In the drawing, 30 denotes a spacer formed between the first and second substrates 12 and 14, and 32 denotes a cover sheet contact.

FIG. 2 is a diagram illustrating a configuration of a projection type image display system in which the transmissive liquid crystal display device shown in FIG. 1 is applied as a liquid crystal display panel.

According to the projection image display system, the light emitted from the light source 36 such as a high voltage mercury lamp or a metal halide lamp is directed in one direction with the aid of the reflector 36a.

The light directed in one direction is incident on the first and second fly-eye lenses (FELs) 38 and 40 so that the illumination area is adjusted to match the size of the effective transmission area of the liquid crystal display panel. Calibration is made. The first FEL 38 is configured by a lens group of small cell units, for example, to realize maximum uniformity using ambient light.

Light from the second FEL 40 is separated into P-polarized light and S-polarized light in a polarizing beam splitter (PBS) array 42, of which only S-polarized light passes.

The polarized light in the PBS array 42 passes through an illumination (or condenser) 44 so that light of a specific color (eg, Red (R); The light is irradiated to the first color reflecting mirror 46 to pass through, and the light of the first color (red R) reflected from the first color reflecting mirror 46 is the first color R filter (i.e., The first liquid crystal display panel 52 and the first color filtering lens (ie, the dichroic lens) 50 reach the first liquid crystal display panel 52, and the red (R) color light is transmitted. The incident first liquid crystal display panel 52 is activated to generate an image corresponding to the R-color.

In addition, the light from which the first color (ie, red R) is removed while passing through the first color reflecting mirror 46 is second color (eg, Green (G); green) in the second color filter 54. Only the light of the light is reflected and the light of the first color (green (G)) reaches the second liquid crystal display panel 58 via the second color filtering lens (ie, the dichroic lens) 56. The second liquid crystal display panel 58 into which two colors (green (G)) light is incident is activated to generate an image corresponding to the G-color.

The third color (for example, Blue (B0) blue) passing through the second color filter 54 passes through the third color delay lens 60 and is reflected by the first third color reflecting mirror 62. Via the condenser lens 64, it is directed to the third color filtering lens (ie, the dichroic lens 68) by the second third color reflecting mirror 66, and passes through the third color filtering lens 68. The light of one third color B reaches the third liquid crystal display panel 70, and the third liquid crystal display panel 70 into which the light of the third color (blue B) is incident is activated and the light is emitted. An image corresponding to the color is generated.

The R / G / B-color images generated by the first to third liquid crystal display panels 70 are combined by the dichroic prism 72 and converted into a complete image, and the image is converted into a projection lens unit ( 74 is implemented as an image of a large screen enlarged on a screen (not shown).

Here, when the liquid crystal display device 10 having the configuration shown in FIG. 1 is applied to the first to third liquid crystal display panels 52, 58, and 70 shown in FIG. If the definition is small, the aperture ratio becomes smaller, which reduces the brightness of the screen and increases the price, making it difficult to implement high resolution.                         

That is, referring to the aperture ratio of one pixel of the liquid crystal display device 10 illustrated in FIG. 3, when 'A' is actually a region through which light is transmitted and 'B' is an entire region of the pixel, the aperture ratio is%. It is "area of A / area of B * 100", and the opening ratio becomes so preferable that it is largely defined.

However, a TFT for applying a signal to a liquid crystal layer or a signal line such as a drain 76 to which an image signal is input and a gate 78 to which a control signal is input is applied to the liquid crystal display element 10 of one pixel. Because of the addition, the aperture ratio of the transmissive type is relatively low compared to other image display elements.

Therefore, when the resolution of the liquid crystal display device is increased, the area of the area through which light is not transmitted remains the same, but the area of the area through which light is transmitted is reduced, resulting in a decrease in aperture ratio, thereby reducing the brightness of the screen.

In consideration of the above, a method of improving the resolution using a liquid crystal display panel having a low resolution has been proposed to compensate for the disadvantage of a transmissive image display panel that is difficult to increase the screen resolution. 4 is a diagram showing a structural example for improving the resolution when a transmissive liquid crystal display panel is employed in the projection image display system shown in FIG.

Referring to FIG. 4, light of the first to third liquid crystal display panels 52, 58, 70 and the first to third colors R / G / B from the liquid crystal display panels 52, 58, 70 is shown. Up to the dichroic prism 72 for synthesizing the same is configured as shown in Figure 2 above, the color selection element for separation of color on the light output side of the dichroic prism 72 to improve the resolution ( 80 and the color switch 82 and the calcite 84 are sequentially interposed.                         

In the above configuration, all of the light synthesized by the dichroic prism 72 is changed to S-wave while passing through the color selection device 80.

The color switch 82 changes the polarization of the light according to the level of the input voltage, so that the polarization is converted while passing through the color switch 82.

In addition, the calcite 84 has a characteristic that the refractive index is converted according to the polarization of the input light, and accordingly adjusting the voltage level input to the color switch 82, the polarization of the light input to the calcite 84 When the polarized light is converted and projected on the screen through the projection lens 74, a result P2 of shaking the pixel P1 in a diagonal direction is obtained, and eventually light passing through the calcite 84 When projected onto the screen through the projection lens 74, the effect of increasing the resolution on the screen is obtained.

Referring to FIGS. 5A and 5B, the screen display principle and the display example of the projection image display system shown in FIG. 4 will be described. The color selection device 80, the color switch 82, and the calcite The pixel P1 is shaken diagonally in the form shown in FIG. 5A while passing through 84, and when the result P2 is projected on the screen S of FIG. 5B, the direction in which the pixel shakes on the screen S is shown. In S1, good resolution characteristics are seen, but resolution characteristics in the opposite direction become considerably poor.

To solve such a disadvantage, if the pixel is shaken in the form shown in FIG. 6A over a total of four times (P1, P2, P3, and P4) in the counterclockwise direction, the screen S is used in each direction (S1.S2). High resolution characteristics are obtained.

However, in order to apply the above method, the response speed of the liquid crystal display device (liquid crystal display panel) must be about 23 times higher than that of the present, and thus it is impossible to apply the method to practical use.

Accordingly, the present invention has been made in view of the above-described situation of the prior art, and two mechanical liquid crystal display panels are applied to R / G / B color light to apply mechanical vibrations in directions crossing each liquid crystal display panel. It is therefore an object of the present invention to provide a resolution correction device for a projection image display system having good resolution characteristics even with the current liquid crystal response speed.

In order to achieve the above object, according to a preferred embodiment of the present invention, the light source, and the light irradiated from the light source and transmitted through the FEL (Fly Eye Lens), the PBS and the illumination lens are transmitted to the first third color (R / G). First and second color reflecting mirrors separated by B, and a first third liquid crystal display panel which is activated when the first third color is reached through a corresponding color filtering lens to realize an image of a corresponding color. A projection type image display system in which an image of an R / G / B color generated by a liquid crystal display panel is combined and projected onto a screen through a projection lens unit, wherein the liquid crystal display panel in which the R / G / B color is reached is 2; Dogs are superimposed and vibrating means associated with a corresponding liquid crystal display panel for vibrating the superimposed liquid crystal display panels corresponding to each color, and a liquid crystal vibration control system for vibrating the liquid crystal display panel by the vibrating means. The resolution correction unit of the projection type image display system configured further equipped with a vibrating means driving section for the output is provided.                     

According to the present invention, the two liquid crystal display panels corresponding to the R / G / B colors are arranged to cross oscillate with each other.

Preferably, the vibrating means driver includes a control to cause the two overlapping liquid crystal display panels to vibrate only at the brightness of the black level.

The vibration means of the present invention is characterized in that the VCM (Voice Coil Motor).

In the resolution correction device of the projection type image display system according to the present invention, two liquid crystal display panels in which light of R / G / B color is received are arranged so that they cross each other by vibrating means under the control of the vibrating means driver. The vibration is caused, and the effect of shaking the pixel in four directions is obtained, resulting in an improvement in the resolution of the image projected on the screen.

Hereinafter, with reference to the accompanying drawings, the present invention will be described in detail.

7 is a diagram illustrating a resolution correction apparatus of a projection image display system according to a preferred embodiment of the present invention.

Referring to the drawings, the configuration of the dichroic prism 72 for synthesizing the light of the first to third colors R / G / B is the same as that of FIG. 2.

In addition, in the embodiment of the present invention, a voice coil motor (hereinafter, referred to as 'VCM') is used as a vibration means. Accordingly, the VCM drive unit according to the embodiment of the present invention represents a vibration means drive unit.

Preferably, according to the present invention, two liquid crystal display panels 52a and 52b are disposed for the R-color, and the liquid crystal vibration control signal from the VCM driver 100 is applied to each of the liquid crystal display panels 52a and 52b. VCM (VCM-R1, VCM-R2) 102, 104 to which (CR1, CR2) is applied are correspondingly provided.

In addition, two liquid crystal display panels 58a and 58b are disposed for the G-color, and the liquid crystal vibration control signal CG1 applied from the VCM driver 100 to apply vibration to each liquid crystal display panel 58a and 58b. VCM (VCM-G1, VCM-G2) 106 and 108 to which CG2 is applied are correspondingly provided.

Similarly, two liquid crystal display panels 70a and 70b are arranged for the B-color and the liquid crystal vibration control signal from the VCM driver 100 is applied to vibrate the liquid crystal display panels 70a and 70b. VCMs (VCM-G1, VCM-G2) 110, 112 to which (CB1, CB2) are applied are correspondingly provided.

According to the present invention, the shaking directions of the two liquid crystal display panels 52a, 52b; 58a, 58b; 70a, 70b provided for the R / G / B colors cross each other (i.e., 90 °; FIG. 8A). V1: V2), and the projection lens (not shown) due to the effect of shaking the pixel four times by the liquid crystal display panels 52a, 52b; 58a, 58b; 70a, 70b for each color. In the case of projected by, good resolution characteristics in the diagonal directions S11 and S12 are obtained on the screen S as in FIG. 8B.

In addition, the VCM driver 100 applies the liquid crystal drive control signals CR1, CR2; CG1, CG2; CB1, CB2 to the VCMs 102, 104; 106, 108, 110, and 112 only at the brightness corresponding to black. It is desirable that the vibration of the display panel be achieved while the display panel is not vibrated at other brightness levels, so that the contrast ratio is increased and the brightness reduction is minimized.

On the other hand, the present invention is not limited to the above embodiments, and various changes and modifications can be made within the scope not departing from the technical gist and gist of the invention. That is, the present invention can be applied not only to the structure of the three-plate type liquid crystal display panel but also to the structure of the single-type liquid crystal display panel as well as to the transmissive and reflective structures.

As described above, according to the resolution correction device of the projection type image display system according to the present invention, two liquid crystal display panels having the current response speed are overlapped and vibrated to cross each other to provide the effect of shaking four times with respect to the pixel. Is improved.

In addition, by vibrating only two brightness levels of the two liquid crystal display panels, the contrast ratio can be improved and the brightness decrease can be minimized.

Claims (4)

First and second color reflecting mirrors separating the light source and the light emitted from the light source and transmitted through the FEL (Fly Eye Lens), the PBS, and the illumination lens into a first third color (R / G / B). When the first third color reaches through the corresponding color filtering lens, the first third liquid crystal display panel which is activated to implement an image of the corresponding color, and displays an image of the R / G / B color generated by the liquid crystal display panel. In the projection type image display system which is combined to be projected on the screen through the projection lens unit, Two liquid crystal display panels in which the R / G / B colors are reached are superimposed; Vibration means associated with a corresponding liquid crystal display panel for vibrating the overlapped liquid crystal display panel corresponding to each color; And a vibration means driver for outputting a liquid crystal vibration control signal for vibrating the liquid crystal display panel by the vibration means. The method of claim 1, And two liquid crystal display panels corresponding to the R / G / B colors are arranged to cross oscillate with each other. The method of claim 1, And the vibrating means driving unit includes a control for causing the two superimposed LCDs to vibrate only at the brightness of the black level. The method of claim 1, The vibration means is a resolution correction device of a projection type image display system, characterized in that the VCM (Voice Coil Motor).

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