KR19980027181A - Lcd projector device - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal projector device, comprising red and blue LCDs (38) and (40), which have a relatively low amount of light as compared to a green LCD (36), to provide light efficiency means (51, 52). In order to maximize, the guide glass 55, 56 having two different refractive indices as a means for guiding the light generated by the light generating means 51 toward the LCD 38, 40 of red and blue The light that is bonded and extinguished at the center of the light guide is incident on the LCD 38, 40 side, or two optical fibers 57, 58 are bonded, and one side of the optical fiber 58 connected to the LCD side is cut off. It is characterized in that the light is extinguished by the cut portion (58a) is configured to be incident to the LCD (38) (40) side.

Description

Lcd projector device

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal projector device, and more particularly, to a liquid crystal projector device in which light efficiency is maximized by compensating a light amount of red light and blue light having a relatively low light amount compared to green light to maintain white balance.

The structure of a general liquid crystal projector device is, as shown in FIG. 1, a light source 1, a reflection mirror 2 reflecting light emitted from the light source 1, and light reflected from the reflection mirror 2. The cold mirror 3 reflects the wavelength of the visible light region and transmits the light in the ultraviolet region and the infrared region, and the red, green, and blue wavelength ranges of the light emitted by the cold mirror 3. When dividing by color, the dichroic separation mirror 4 and several total reflection mirrors 5 and 6 which irradiate the red, green and blue light separated by the dichroic separation mirror 4 with the LCD which is a light modulation means. And (7) (8), a dichroic separation prism (9), which is a color synthesizing means for combining a display image of red, green, and blue of light emitted from the total reflection mirror (6) and passing through the LCD; And a projection lens 10 for projecting the enlarged image on the screen.

In addition, a condensing lens 11 suitable for injecting light reflected from the total reflection mirrors 5, 6, 7, and 8 into the incident pupil position of the projection lens 10 around the dichroic separation prism 9. (15) (19), first polarizing plates 12, 16 and 20 for linearly polarizing the red, green, and blue regions, respectively, and for changing the polarization state of light polarized by the polarizing plate according to an electrical image signal. LCD, 13, 17 and 21 for image control of red, green, and blue, and the polarized light changed by the LCD, and transmits only one direction of light and absorbs the remaining light to recognize the electric image signal. Second polarizing plates 14, 18, 22 for display by the display device are provided.

However, conventionally, there is a problem in that the spectral distribution of the light source forms a distribution that does not match the white balance. That is, when the ratio of red, green, and blue of NTSC is 2.6: 5.1: 1, and 2.9: 9.9: 1 in the case of HDTV as a standard for implementing white balance, the light source generally used most commonly in a liquid crystal projector is known. The light quantity ratio of the phosphorus 150W metal halide lamp is I _RED : I _GREEN : I _BLUE = 2.6: 16.6: 1. The spectral distribution of the metal halide lamp and the color distribution by optical color separation and synthesis are shown in FIGS. 2 and 3.

In the conventional LCD projector, in order to adjust the white balance, the light amount of green light is {(16.6-5.1) / 16.6} × 100% = 69% in NTSC, and {(16.6- 9.9) / 16.6} × 100% = 40.4% of light has to be blocked intentionally.

The object of the present invention devised in view of these problems is to maximize the light efficiency by maintaining the white balance without blocking the amount of green light.

Another object of the present invention is to compensate for the light sources of red and blue light to maintain white balance.

1 is a configuration diagram of a general liquid crystal projector device.

2 and 3 are graphs showing the distribution of red, green, and blue light by spectral distribution and color separation and synthesis of a light source using a 150W metal halide lamp as a light source.

4 is a configuration diagram of a liquid crystal projector device according to the present invention.

5A and 5B are a perspective view and a plan view of an auxiliary light source unit and an optical guide unit applied to the liquid crystal projector device of the present invention;

6a and 6b are a perspective view showing a light guide unit and a perspective view of the light guide unit according to another embodiment of the present invention.

Explanation of symbols on the main parts of the drawings

31; Light sources 36,38,40; LCD for red, green and blue

51; A light source 52 of the light generating means; Reflector of light generating means

55; Incident light guide glass 56; Output side light guide glass

57; Incident side optical fiber bundle 58; Output Fiber Bundle

In order to achieve the object of the present invention, a green, red, blue image control LCD for changing the polarization state according to the light source, the polarized light emitted from the light source according to the electrical image signal, and the red and blue LCD of the LCD In addition, there is provided a liquid crystal projector device comprising an auxiliary light generating means for supplying light to the light guide means for guiding the light of the auxiliary light generating means to the red and blue LCD.

Hereinafter, the present invention as described above will be described in more detail based on one embodiment shown in the accompanying drawings.

In the liquid crystal projector device according to the present invention, as shown in Figs. 4 and 5, in order to compensate for the insufficient amount of red light and blue light, the auxiliary light source unit and the auxiliary light source unit are provided in the red LCD 38 and the blue LCD 40. Each of the optical guides for guiding the emitted light toward the LCD is installed.

The auxiliary light source unit includes a light source 51 through which light is emitted, a reflector 52 and a color filter 53, and the light guide unit includes an incident light guide glass 54 having a center of the light guide. And the emission-side glass 55 serving as a cover surrounding the light guide glass 54, and a reflecting mirror 56 is provided behind the cover glass 55. As shown in FIG.

In the drawings, reference numeral 31 denotes a light source, 32 a reflector, 33 a cold mirror, 34, 37 and 42 are dichroic separation mirrors, 35, 39 and 41 are total reflection mirrors, and 36, 38 and 40 are red, green and blue, respectively. LCD, and 43 is a projection lens.

The light source 51 of the auxiliary light source unit is elongated in the vertical direction of the light guide unit, and the reflector 52 surrounds the light source 51, and the reflector 52 is formed of an ellipse or parabolic column. In this case, when the reflector has the shape of an elliptic pillar, the reflector is formed such that the first focus point is the light emitting part and the second focus point is an adhesive surface of the light guide and the color filter. In addition, when the reflecting mirror is in the shape of a parabolic column, a light collecting means is provided between the surface of the color filter and the light source.

The refractive index of the incident side optical glass 54 in which the optical center of the optical guide portion is formed is higher than the refractive index of the emission side glass 55 (n _CO n _CL ), and the thickness of the emission side glass 55 is incident. The light incident from the auxiliary light source portion formed to be larger than the thickness of the side glass 54 passes through the center of the light guide portion and leaks toward the LCD as an Everescent wave.

The principle in which the light of the Evernet wave is guided is the same as in the graph shown in FIG. 5C. That is, when light is incident as shown by the arrow in the figure, the refractive index distribution is as follows.

-aya: n _CO

-by -a: n _CL2

-cy -b: n _LC

ayd: n _CL1

And, the electric field area (Electric Field) by the second light source

TE-wave, an electric field region parallel to the x-axis,

The TM-wave, an electric field region perpendicular to the x axis,

here, Is the refractive index in each region, Is As a wave number.

Wave numbers for the y-axis of the TE-wave and TM-wave Is

TE digger

Area I

Area IV

Area III

Area II

TM digger

Area I

Area IV

Area III

Area II

The electric field in the area

And boundary Condetion

By A ₃ = B ₃ = 0

therefore,

Area I Is an Evernest wave that progresses to the Z axis and gradually exits to region IV.

When the white balance is increased by increasing the amount of light incident on the LCD 38 and 40 of red and blue in the above manner, it is possible to maximize the light efficiency of the entire liquid crystal projector without reducing the amount of light of the green LCD 36.

As another embodiment of the present invention, as shown in Fig. 5a, an embodiment using the optical guide portion using the optical fiber bundle can be provided.

That is, the optical guide portion according to another embodiment of the present invention uses the optical fiber bundle as shown in FIG. 5b as the optical guide portion, and the optical fiber bundle includes an incident-side optical fiber bundle in which light generated from the auxiliary light source 51 is incident ( 57 and an exit-side optical fiber bundle 58 which is bonded to the incident-side optical fiber bundle 57 and sends light to the LCD 38 and 40 sides. The connecting portion of the incident side optical fiber bundle 57 and the exit side optical fiber bundle 58 has a constant incision in the lower part of the output side optical fiber bundle 58 so that the aberration wave is formed through the cutout 58a. It leaks and enters the LCD.

As described above, the liquid crystal projector according to the present invention maintains the white balance by a method of maximizing light efficiency without blocking green light by compensating for the amount of red light and blue light with a relatively small amount of light compared to green light by installing an auxiliary light source. It is effective.

Claims (3)

A light source; A green, red, and blue image control LCD for changing the polarization state of the light emitted from the light source and polarized according to the electric image signal; Auxiliary light generating means for supplying additional light to the red and blue LCDs of the LCD; And a light guide means for guiding the light of the auxiliary light generating means to the red and blue LCDs. The liquid crystal projector device according to claim 1, wherein the light guide means is configured such that light guide glasses having two different refractive indices are bonded to each other so that light that is extinguished at the center of the light guide is incident on the LCD side. The liquid crystal projector device according to claim 1, wherein the optical guide means is configured such that two optical fibers are joined, and one side of the optical fiber connected to the LCD side is incised and the light disappeared into the cut portion is incident on the LCD side. .