KR100531366B1 - Flat panel display device using hologram pattern liquid crystal - Google Patents

Abstract

The present invention relates to a projection display device that selectively adjusts color by forming a pattern with a hologram on a liquid crystal. Particularly, the color selection unit comprises an R, G, B color filter made of a liquid crystal having a hologram pattern between transparent electrodes, and inputs a color. The incident light is separated into R, G, and B light by selecting a specific wavelength of light emitted from the light source according to a selection signal and adjusting and outputting the amount of transmitted light of the selected specific wavelength, and the display element is separated according to the color signal of the image. The image corresponding to the light of the color selected by the color selector is displayed, and the image signal controller receives an image signal input from the outside and outputs the color signal of the image output to the display element and the color selection signal of the color separation controller. By synchronizing the image, the image of accurate color is realized and the image signal and the color separation device are effectively The effect of exactly the same without a car.

Description

Flat panel display device using hologram pattern liquid crystal

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a projection display device, and more particularly, to a flat panel display device using a hologram pattern liquid crystal which forms a pattern in a hologram on a liquid crystal and selectively adjusts color.

BACKGROUND ART Generally, a flat panel display system that implements a large screen includes a projection display system that displays a large screen by enlarging and projecting a small screen.

1 is a block diagram illustrating a general color projection display device.

That is, the light emitted from the light source 11 such as a lamp is collected and progressed in one direction by the reflector, and the transmitted light is transmitted by the red filter 12 and the R light is transmitted. (Blue) Light is reflected. R light transmitted through the R filter 12 is reflected by the R mirror 13 and irradiated to the red LCD 17.

On the other hand, the green and blue light reflected by the R filter 12 is incident to the blue filter 14, the blue filter 14 reflects the green light to irradiate the green LCD 18, the blue light is It passes through the blue filter 14. The blue light transmitted through the blue filter 14 is reflected by the first blue mirror 15 and the second blue mirror 16 and irradiated to the blue LCD 19.

Each of the R, G, and B LCDs 17, 18, and 19 displays an image for each color by an electrical signal, and the image of each color is synthesized by the prism 101 and proceeds to the projection optical system 102. do. That is, the color image synthesized by the prism 101 is magnified by the projection optical system 102 to be projected on the screen 103 and the user views the image.

However, in the same manner as in FIG. 1, the light emitted from the light source 11 must be separated by using a plurality of color filters and then synthesized again, and three display elements corresponding to each color must be used. Difficult to sort and raises the price.

In order to solve this problem, a rotating color separation apparatus has been conventionally proposed.

2 shows a configuration of a conventional rotary color separation device using one display element.

That is, the rotating color separation apparatus of FIG. 2 is designed as a method for implementing a color image with one display element instead of using three display elements in the conventional color display device as shown in FIG. 1.

In other words, the light from the light source 21, such as a lamp, is directed to a color wheel 22, which is a rotating color separation device. The color wheel 22 is composed of color filters corresponding to three colors of R, G, and B to separate the color of light, and each of the R, G, and B color filters is divided into a predetermined ratio area in the entire color wheel 22. Lost

As the color wheel 22 rotates, R, G, and B color filters are sequentially irradiated with light emitted from the light source 21. The light 26 transmitted through each of the color filters R, G, and B of the color wheel 22 has a color corresponding to each color filter. At this time, the light 26 transmitted through the color wheel 22 is irradiated to the display element 28 by the optical system 27. The display element 28 displays a color image corresponding to the transmitted light 26 of each color by an electrical signal, and sequentially displays R, G, and B colors for 1/60 second constituting one screen in rapid time. One screen is displayed.

At this time, in order to realize accurate color of the screen, the image signal and the color wheel 22 should be synchronized to correspond to each of R, G, and B, which are reflected by the marker 24 attached to the motor 23 of the color wheel 22. Each time the color wheel 22 rotates, the sensor 25 detects the light and synchronizes the image signal with the R, G, B filter region of the color wheel 22 detected by the marker 24 by a pre-calculated relationship. Let's do it.

However, in this method, two times, that is, the time at which one color of the image signal should be displayed and the start of the corresponding color filter which is the same as the corresponding color of the image signal as the color wheel 22 rotates, The marker 24 must be located on the motor 23 axis portion of the color wheel 22 and must be sensed by the sensor 25 so that the time irradiated exactly matches. Therefore, the adhesion position of the marker 24 has to be calculated and determined in advance according to the configuration of the device, and there is a difficulty in aligning the correct position. In addition, when the position of the marker 24 is slightly displaced, an error is generated between the image signal and the light transmitted by the color wheel 22, and these errors accumulate and eventually display the image signal realized by the display element and the color displayed as the actual image. Has a different appearance.

In addition, the weight of the marker 24 makes the weight of the entire surface of the color wheel 22 uneven, resulting in noise and vibration problems due to irregular rotation and causing deterioration of the image due to uneven light transmittance.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to achieve a stable and excellent color image by effectively matching a color signal of a display device with a corresponding color of a color separation device in implementing a color image with one display device. It is to provide a flat panel display device using a hologram pattern liquid crystal for displaying a.

The flat panel display device using the hologram pattern liquid crystal according to the present invention for achieving the above object is composed of an R, G, B color filter composed of a light source and a liquid crystal having a hologram pattern between the transparent electrode, By selecting a specific wavelength of the emitted light and by adjusting the amount of transmitted light of the selected specific wavelength output by the color selection unit for separating the incident light into R, G, B light respectively, by the color selection unit in accordance with the color signal of the image The display device for displaying an image corresponding to the light of the selected color, and proceeding the displayed image to the projection optical system, and the color selection signal to select and separate the corresponding color of the image signal input from the outside in the color selection unit; A color separation controller outputting the color selection unit and an image signal input from an external device to be output to the display device Characterized in that the configuration including on the color signal and the video signal control unit for synchronizing the color selection signal of the color separation control.

Each of the R, G, and B color filters of the color selector selectively transmits or diffracts only the wavelength of the corresponding color according to the applied voltage, and transmits the wavelength of the other color as it is.

Each of the R, G and B color filters of the color selector is composed of liquid crystal molecules and monomers formed in a hologram pattern between the first transparent electrode and the second transparent electrode, and the liquid crystal molecules and monomers are periodically arranged to form a band shape. Characterized in having a.

The hologram pattern is characterized in that the liquid crystal monomer mixture is irradiated with a laser reference light and a laser light, a band-shaped interference fringe formed by the phase difference between the two laser light.

Each of the R, G and B color filters of the color selector selects light having a desired wavelength by adjusting the period and interval of the refractive index grating of the hologram pattern liquid crystal, and corresponds to the magnitude of an applied voltage of a corresponding pixel associated with an external image signal. It characterized by adjusting the amount of transmitted light.

When the incident light is incident on the hologram pattern liquid crystal in the color selector and no voltage is applied to the liquid crystal, a refractive index grating is formed by the hologram pattern, so that incident light having a specific wavelength does not pass through the liquid crystal molecules and is diffracted.

When incident light is incident on the hologram pattern liquid crystal in the color selection unit, when voltage is applied to the liquid crystal, the liquid crystal molecules are aligned in a predetermined direction so that incident light having a specific wavelength passes through the liquid crystal molecules.

Other objects, features and advantages of the present invention will become apparent from the following detailed description of embodiments taken in conjunction with the accompanying drawings.

Hereinafter, with reference to the accompanying drawings illustrating the configuration and operation of the embodiment of the present invention, the configuration and operation of the present invention shown in the drawings and described by it will be described as at least one embodiment, By the technical spirit of the present invention described above and its core configuration and operation is not limited.

3 is a block diagram illustrating a color image of a projection display device according to an exemplary embodiment of the present invention, which includes a light source 31 such as a lamp, a color selector 32 for sequentially separating and transmitting colors, and a color selector. An illumination optical system 33 for condensing the light emitted from 32 in a predetermined direction is disposed on the same light path line. A display element 34 for displaying an image by an electrical signal is disposed at an angle with respect to the illumination optical system 33, and is projected with the projection optical system 35 to enlarge and project the image displayed on the display element 34. The screen 36 for forming an image is disposed on the same optical path.

In addition, an image signal controller 37 for receiving and processing an image signal from outside and controlling an internal circuit, and a color separation controller for controlling a color of the image signal to be selected and separated by the color selector 32 ( 38).

The light emitted from the light source 31 of the present invention configured as described above proceeds to the color selector 32.

The color selector 32 includes R, G, and B color filters composed of a hologram pattern liquid crystal between transparent electrodes. The color selector 32 receives R, G, and B light of the corresponding color among the light incident from the light source 31 according to the signal of the display color of the display element 34 under the control of the color separation controller 38. Permeate sequentially. That is, colors are sequentially separated by the color wheel.

Hereinafter, the color selection separation method of the color selection unit 32 will be described in detail.

As shown in FIG. 4, the color selector 32 includes R, G, and B filters 42, 43, and 44. A transparent electrode is provided across the filter of each color, and the hologram pattern liquid crystal is arrange | positioned between them. The transparent electrode of each filter applies a voltage to the liquid crystal so as to drive the liquid crystal, and the intensity of the applied voltage is controlled by the color separation controller 38.

The following is an operating principle of the hologram pattern liquid crystal.

That is, the hologram pattern liquid crystal includes a liquid crystal molecule set 53 and a monomer 54 formed in a hologram pattern between the first transparent electrode 51 and the second transparent electrode 52 as shown in FIG. 5A.

The liquid crystal molecule set 53 and the monomer 54 are periodically arranged to have a band shape.

In addition, since the refractive indices of the liquid crystal molecules 53 and the refractive indices of the monomers 54 are different from each other, a periodic refractive index grating is formed. Periodic refractive index gratings have the property of diffracting light.

In order to form the hologram pattern liquid crystal, the laser reference light 58 and the laser light 56 are irradiated to the liquid crystal monomer mixed liquid 55 as shown in FIG. 5B. A band-shaped interference fringe is formed by the phase difference of the two laser lights to form the hologram pattern 59. The hologram pattern 59 may adjust thickness, period, etc. by the diffraction element 57. As the diffractive element 57, a pattern made in advance by a lens or a computer can be used.

By the band-shaped hologram pattern 59, the bright monomer in the liquid crystal monomer mixture 55 is polymerized by light, and at the same time, the liquid crystal in the bright region is pushed out into the dark region. As the laser light continues to be irradiated, the light is divided into a polymer region of a bright portion and a liquid crystal region of a dark portion, and thus has an alternate arrangement.

This periodic arrangement eventually forms a refractive index grating whose refractive index varies periodically because the refractive indices of the liquid crystal molecule set 53 and the monomer 54 are different.

6 illustrates a driving principle of the hologram pattern liquid crystal.

That is, when the incident light 61 is incident on the hologram pattern liquid crystal and no voltage is applied to the liquid crystal, the refractive index grating is formed by the hologram pattern as shown in FIG. 6A. The diffracted light 62 exits. That is, since the voltage-free liquid crystal molecule array 63 is irregular, light does not pass through the liquid crystal molecules and the refractive index grating is maintained.

On the other hand, when a voltage is applied to the liquid crystal, the incident light 61 passes through the liquid crystal and exits to the transmitted light 64 as shown in FIG. 6B. That is, in the voltage-applied liquid crystal molecule array 65, the liquid crystal molecules are aligned in a predetermined direction by the applied voltage so that the refractive index of the liquid crystal molecules and the refractive index of the monomer are the same, so that the refractive index grating is not formed, so that incident light is transmitted as it is.

Since the regularity of the arrangement of the liquid crystal molecules occurs in response to the magnitude of the voltage applied to the liquid crystal, the amount of light passing through the liquid crystal is adjusted by adjusting the applied voltage.

On the other hand, since the light diffracted by the refractive index grating of the hologram pattern liquid crystal is related to the period and interval of the grating, it is possible to selectively adjust the light of the desired wavelength by adjusting the period and interval of the grating.

As a result, the wavelength corresponding to the amount of light transmitted and the color of the light can be adjusted in the hologram pattern liquid crystal.

4 again, the color selection separation by the hologram pattern liquid crystal is explained in detail.

That is, the incident light 41 emitted from the light source is made up of the sum of the R, G, and B incident lights 411, 412, and 413.

The R, G, B incident light 411, 412, 413 is incident on the R, G, B filters 42, 43, 44.

The filter of each color selectively transmits or diffracts only the wavelength of the corresponding color and transmits the wavelength of the other color as it is.

That is, when the R incident light 411 is incident on the R filter 42, if there is no R filter applied voltage 45, the R incident light 411 is diffracted by the periodic refractive index grating of the hologram pattern liquid crystal of the R filter 42 and R is Exit to diffracted light 482. On the other hand, when the R filter applying voltage 45 is applied, no periodic refractive index grating of the hologram pattern liquid crystal is formed, so that the R incident light 411 passes through the filter and proceeds to the display element 34 as the R transmitted light 481.

At this time, the R transmitted light 481 transmitted through the R filter 42 passes through the G filter 43 and the B filter 44 as they are.

In addition, the R diffracted light 482 may be sent to a region where the angle of incident light and the period and interval of the refractive index grating may be adjusted to adjust and remove the traveling direction and angle.

Likewise light of another color is selectively transmitted or diffracted in the filter of that color.

As a result, the color selector 32 selectively transmits only the light of a desired color among the incident light to separate colors.

R, G, and B light separated from the color selector 32 are collected by the illumination optical system 33 and proceed to the display element 34.

The display device 34 sequentially receives R, G, and B light incident through the illumination optical system 33 by receiving an electrical signal from the image signal controller 37 according to the input image signal. That is, the display device 34 is a display device for displaying an image according to an image signal, and implements a screen by sequentially displaying R, G, and B images. For example, if a screen is implemented at 60 Hz, 1/60 sec is divided by 3 to display R image for 1/180 sec, G image for 1/180 sec, and B image for 1/180 sec. It is displayed to compose one screen.

The display element 34 is representative of Texas Instruments' Digital Micromirror Array (DMD).

Since the light of the color selected by the color selector 32 is irradiated to the display element 34, the display element 34 displays an image corresponding to each of R, G, and B light amounts, and the displayed image is a projection optical system. Proceed to (35).

The projection optical system 35 enlarges and projects the displayed image on the screen 36, and the user views the image projected on the screen 36 from the front or the rear.

On the other hand, the color of the color selection unit 32 and the image color signal of the display element 34 must be equally matched to display an image of the correct color.

To this end, the image signal controller 37 receives an image signal and divides the image signal of one screen into an image signal corresponding to each of R, G, and B colors, and transmits the signal to the display element 34. It also transmits to the separation control unit 38.

The display element 34 receiving the image signal of each color displays an image of the corresponding color, and at the same time, the color separation controller 38 controls the light of the color to be selected and transmitted by the color selector 32. That is, the image signal controller 37 displays the correct color by synchronizing the color signal to the display element 34 with the color selection signal of the color separation controller 38.

Therefore, the color of the light selected by the color selector 32 and the image of the color displayed on the display device 34 may be matched to implement an accurate image.

7 is a time configuration diagram of the color separation and synchronization.

That is, a separate sensor or a mechanical device is not required to synchronize the color signal and the color to be illuminated, and since the signal is directly synchronized with the image signal controller 37, it is possible to accurately synchronize without errors.

As described above, the flat panel display device using the holographic pattern liquid crystal according to the present invention has an effect of realizing an accurate color image and effectively matching the image signal with the color separation device without error.

Those skilled in the art will appreciate that various changes and modifications can be made without departing from the spirit of the present invention.

Therefore, the technical scope of the present invention should not be limited to the contents described in the embodiments, but should be defined by the claims.

1 is a configuration diagram of a conventional color projection display device

2 is a block diagram of a conventional rotating color separation device

3 is a configuration diagram of a color projection display device according to the present invention;

4 is a view illustrating an example of color selection and separation by the hologram pattern liquid crystal of the color selection unit of FIG.

FIG. 5A illustrates a structure of the hologram pattern liquid crystal of FIG. 4. FIG.

FIG. 5B illustrates an example of forming the hologram pattern liquid crystal of FIG. 4. FIG.

FIG. 6A is a diagram for describing a driving principle when no voltage is applied to the hologram pattern liquid crystal of FIG. 4. FIG.

6B is a diagram for describing a driving principle when a voltage is applied to the hologram pattern liquid crystal of FIG. 4.

7 is a time configuration diagram of a color separation signal according to the present invention;

Explanation of symbols for main parts of the drawings

31 lamp 32 color selector

33: illumination optical system 34: display device

35: projection optical system 36: screen

37: video signal control unit 38: color separation control unit

Claims (10)

Light source; It is composed of R, G, B color filters made of liquid crystal having a hologram pattern between the transparent electrodes, the power supply of any one of the R, G, B color filters according to the color selection signal is controlled in the light source A color selector for separating the incident light into R, G, and B light by selecting a wavelength of a corresponding color light from the emitted incident light and adjusting and outputting the amount of transmitted light of the selected wavelength; A display element configured to display an image corresponding to light of a color output through the color selector according to a color signal of the image, and to advance the displayed image to a projection optical system; A color separation controller for outputting a color selection signal to the color selection unit so that the corresponding color of the image signal input from the outside can be selected and separated from the color selection unit; And And a video signal controller configured to receive an image signal input from an external device and synchronize the color signal of the image output to the display element and the color selection signal of the color separation controller. device. The method of claim 1, Each of the R, G, and B color filters of the color selector transmits a wavelength of a corresponding color when a voltage is applied, and diffracts the wavelength of the corresponding color when a voltage is not applied. The color filter of claim 1, wherein each of the R, G, and B color filters of the color selector It consists of liquid crystal molecules and monomers formed in a hologram pattern between the first transparent electrode and the second transparent electrode, wherein the liquid crystal molecules and monomers are arranged periodically to have a band-shaped flat display using a hologram pattern liquid crystal device. The method of claim 3, wherein And a refractive index grating when the voltage is not applied to the refractive index of the liquid crystal molecules and the refractive index of the monomers. The method of claim 3, wherein the hologram pattern is The liquid crystal monomer mixture is irradiated with a laser reference light and a laser light, the flat panel display device using a holographic pattern liquid crystal, characterized in that formed by a band-shaped interference fringe by the phase difference between the two laser light. The color filter of claim 1, wherein each of the R, G, and B color filters of the color selector Hologram pattern liquid crystal, characterized in that for controlling the period and interval of the refractive index grating of the hologram pattern liquid crystal to select the light of the desired wavelength, and to adjust the amount of transmitted light corresponding to the magnitude of the applied voltage of the pixel associated with the external image signal. Flat panel display device using. The method of claim 1, When incident light is incident on the hologram pattern liquid crystal of the color selection unit, when no voltage is applied to the liquid crystal, a refractive index grating is formed by the hologram pattern so that the wavelength of the corresponding color light among the incident light does not pass through the liquid crystal molecules and is diffracted. The flat panel display element using the hologram pattern liquid crystal made into it. The method of claim 1, When incident light is incident on the hologram pattern liquid crystal of the color selection unit, when voltage is applied to the liquid crystal, the liquid crystal molecules are aligned in a predetermined direction, and the wavelength of the corresponding color light among the incident light is transmitted through the liquid crystal molecules as it is. Flat panel display device using. The method of claim 1, wherein the image signal controller An image signal of one screen input from the outside is divided into image signals corresponding to each of R, G, and B colors, and the separated image signals of each color are simultaneously transmitted to a display element and the color separation controller, and the color selection unit A flat panel display device using a hologram pattern liquid crystal, characterized by matching a selected color with a video color signal of a display device. The method of claim 1, And each of the R, G, and B color filters of the color selection unit transmit the wavelengths of other colors as they are, regardless of whether a voltage is supplied or not.