KR100207725B1 - Reflection type projector - Google Patents

Abstract

Disclosed is a reflective project device capable of increasing the brightness of light projected on a screen.

The disclosed reflective project apparatus includes a light source for generating and emitting light, a polarizing beam splitter for transmitting or reflecting incident light according to a polarization component, and converting a traveling path of the incident light, and being disposed adjacent to one exit surface of the polarizing beam splitter A first dichroic mirror for dividing the light beams according to the wavelength, a second dichroic mirror for transmitting or reflecting daylight diverged from the first color mirror, and a second dichroic mirror for generating and reflecting an image from light divergent from the first dichroic mirror. The first display element, the second and third display elements for generating and reflecting an image from each light branched from the second dichroic mirror, and the light emitted from one exit surface of the polarizing beam splitter are focused and diverged to reduce the width thereof. Condensing means to be incident on the first, second and third display elements while being disposed adjacent to the other exit surface of the polarizing beam splitter, and thus half of the first, second and third display elements. And characterized in that it comprises a projection lens unit for enlarging and projecting the path is the converted light towards the screen by the polarization beam splitter.

Description

Reflective Project Device

The present invention relates to a reflective project apparatus, and more particularly, to a reflective project apparatus capable of increasing the brightness of light projected on a screen.

In general, a project apparatus is an apparatus for providing an image by projecting an image generated by the image generating means onto a screen using a separate light source. This project apparatus is classified into a transmission type and a reflection type according to the shape of the image generating means described above.

1 is a schematic diagram showing an optical arrangement of a conventional reflective project apparatus. As shown in the drawing, a conventional reflective project apparatus includes a light source 10 for generating and irradiating light, a color wheel 20 for selectively transmitting a predetermined color of incident light, and a scrambler for mixing the incident light to form a uniform light beam ( 30, a focusing lens 32, a collimating lens 34, a polarizing beam splitter 40, a display element 50 for generating an image, and a projection lens unit 60 for magnifying and projecting incident light. It is configured by.

The light source 10 includes a lamp 11 for generating light such as a metal halide, xenon, and the like, and a reflector 13 for reflecting the light emitted from the lamp 11 and guiding a progress path thereof. The color wheel 20 is rotatably installed by the drive motor 21 on the optical path between the light source 10 and the scrambler 30, and the red (R), green (G) and blue (B). Three colors are evenly distributed throughout the wheel. The color wheel 20 is rotated a predetermined number of times while one screen is formed on a screen (not shown).

The scrambler 30 mixes the incident light by diffused reflection so that the brightness distribution becomes uniform light. The collimating lens 34 converges divergent light incident to be parallel light.

The polarizing beam splitter 40 is disposed on an optical path between the collimating lens 34 and the display element 50, and passes through and reflects the incident light on the mirror surface 41 according to the polarization component of the incident light. Convert That is, light incident from the light source 10 side is selectively transmitted or reflected depending on its polarization component, that is, p- or s-polarized light. 1 shows an example in which light transmitted through the polarization beam splitter 40 is used as effective light. As the display device 50, a liquid crystal display (FLCD: Ferroelectric Liquid Crystal Display) employing a ferroelectric liquid crystal having excellent response speed characteristics is employed. The light transmitted through the ferroelectric liquid crystal layer of the display element 50 is reflected by the reflecting plate of the display element 50 and passes through the ferroelectric liquid crystal layer again to the polarization beam splitter 40. In this case, light passing through the ferroelectric liquid crystal layer is driven and polarized by each pixel unit to display an image.

Among the light reflected by the display device 50 and re-injected into the polarization beam splitter 40, the light whose polarization direction is changed by 90 degrees is reflected by the mirror surface 41 of the polarization beam splitter 40 and is projected to the projection lens unit. Heading toward (60), it passes through this projection lens unit 60 and is projected onto a screen (not shown).

The conventional reflective project device configured as described above has a color wheel 20 on the optical path to implement a color, thereby realizing one screen by sequentially irradiating three colors on the screen. Therefore, since it has a light efficiency corresponding to 1/6 of the amount of light emitted from the light source 10 in theory, there is a problem that the brightness of the image projected on the screen is lowered.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object thereof is to provide a reflection type project apparatus having a structure in which image brightness is improved.

1 is a schematic view showing an optical arrangement of a conventional reflective project apparatus,

2 is a schematic view showing an optical arrangement of a reflective project apparatus according to an embodiment of the present invention;

3 is a schematic view showing an optical arrangement of a reflective project apparatus according to another embodiment of the present invention.

* Explanation of symbols for main parts of the drawings

110: light source 120: light mixing means

130: relay lens unit 133: focusing lens

135: collimating lens 150: polarizing beam splitter

160,180: first and second dichroic mirror 161,181: first and second dichroic light

170,190,200: First, second and third condenser lens unit

171,191,201,300: Convergence Lens 173,193,203: Divergence Lens

175, 195, 205: first, second and third display elements 200: projection lens unit

310,320,330: first, second and third diverging lenses

Reflective project device according to the present invention for achieving the above object is a light source for generating and emitting light; A polarization beam splitter which transmits or reflects incident light according to a polarization component to convert a traveling path of the incident light; A first dichroic mirror disposed adjacent to one exit surface of the polarizing beam splitter and splitting incident light according to a wavelength; A second dichroic mirror for transmitting or reflecting daylight branched from the first color mirror according to a wavelength; A first display element for generating and reflecting an image from light diverged from the first dichroic mirror; Second and third display elements for generating and reflecting an image from each light branched from the second dichroic mirror; Condensing means for focusing and diverging light emitted from one exit surface of the polarizing beam splitter to be incident on the first, second, and third display elements while the width thereof is reduced; A projection lens unit disposed adjacent to another exiting surface of the polarizing beam splitter to enlarge and project the light reflected from the first, second and third display elements and whose path is converted by the polarizing beam splitter toward a screen; Characterized in that.

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

2 is a schematic view showing an optical arrangement of a reflective project apparatus according to an embodiment of the present invention.

As shown, the reflective project apparatus of the present invention includes a light source 110, a polarizing beam splitter 150 for converting a propagation path of incident light, and first and second dichroic mirrors for branching incident light according to wavelengths. 180, first, second and third display elements 175 (195 and 205) for generating and reflecting an image, condensing means for focusing and diverging light, and expanding and projecting incident light toward the screen. It is configured to include a projection lens unit 210.

The light source 110 includes a lamp 111 for generating light and a reflector 113 for reflecting the light emitted from the lamp 111 and guiding a path of the light. The reflector 113 is an ellipsoidal mirror having the position of the lamp 111 as one focal point and the point where the light is focused at another focus, or is emitted from the lamp 111 with the position of the lamp 111 as one focal point. And parabolic mirrors configured to be parallel light reflected by the reflector 113.

Here, the light mixing means 120 to diverge / converge or diffuse the incident light to be uniform light on the optical path between the light source 110 and the polarization beam splitter 150 and a relay to focus the incident light to be parallel light. It is preferable that the lens unit 130 is further provided. As illustrated, the light mixing means 120 may employ a rectangular parallelepiped scrambler 125 made of glass having an incident surface and an exit surface perpendicular to the optical axis so that the incident light is diffusely reflected to become uniform light. The aspect ratio of the exit surface 125a of the scrambler 125 is proportional to the aspect ratio of the first, second, and third display elements 175, 195, and 205. 125, the reflector 113 is preferably an ellipsoid. The relay lens unit 130 focuses the light transmitted through the light mixing means 120 to be parallel light. The relay lens unit 130 focuses the collimating lens 133 to emit incident light and the diverging light incident on the optical path between the focusing lens 133 and the polarization beam splitter 150 to focus the incident light. Collimating lens 135 to be included. Accordingly, the light incident from the light source 110 becomes parallel light with a wider width and is incident on the polarizing beam splitter 150.

The polarizing beam splitter 150 is disposed on an optical path between the light source 110 and the first dichroic mirror 160, and passes through or reflects the incident light on the mirror surface 151 according to the polarization component of the incident light. Convert That is, the light incident from the light source 110 is selectively transmitted or reflected depending on the polarization component, that is, p- or s-polarized light.

The first dichroic mirror 160 is preferably disposed to be adjacent to one exit surface of the polarization beam splitter 150 to diverge incident light according to a wavelength. That is, the first color light 161, for example, the red (R) light, may be reflected to transmit the remaining color light. In this case, one light diverged from the first dichroic mirror 160 is directed toward the second dichroic mirror 180, and the other light diverged from the first dichroic mirror 160 is directed toward the first display element 175. . Preferably, the second dichroic mirror 180 is configured to transmit or reflect the sunlight incident to the second dichroic mirror 160 according to the wavelength. That is, the second color light 181, for example, blue (B) light, may be reflected and the remaining color light 183, for example, green (G) light, may be transmitted. In this case, the second color light 181 reflected from the second dichroic mirror 180 is directed toward the second display element 195, and the third color light 183 transmitted through the second dichroic mirror 180 is the third display. Facing the device 205.

The first display element 175 generates and reflects an image from the light diverged from the first dichroic mirror 160, that is, the first color light 161. The second and third display devices 195 and 205 generate and reflect an image from each of the light diverged from the second dichroic mirror 180, that is, the second and third color lights 181 and 183. Each of the first, second and third display elements 175, 195 and 205 is preferably a ferroelectric liquid crystal display (FLCD) for generating and reflecting a color image. Each of the display elements 175, 195, and 205 is configured to change the polarization state of the light passing through the ferroelectric liquid crystal layer in each pixel unit according to the driving voltage, and to reflect the light incident by the reflector provided on the rear surface thereof. do. Therefore, the light, for example, red light, green light, and blue light of each color polarized by the pixel unit in each of the display elements 175, 195, and 205 is directed toward the polarization beam splitter 150. The first, second and third display elements 175, 195 and 205 may be a movable mirror device (DMD). The movable mirror device includes a plurality of reflecting mirrors having a two-dimensional array structure, each reflecting mirror corresponding to a pixel, and independently hinged to have various reflection angles for incident light. Therefore, the movable mirror device forms an image by varying the reflection direction of each reflecting mirror according to the applied signal. In this case, a phase retardation plate is further provided in front of the movable mirror device.

The condensing means focuses and diverges the light emitted from one exit surface of the polarization beam splitter 150 to reduce the width of the first, second and third display elements 175 (195) and 205. To be incident on. The condensing means includes a first condenser lens unit 170 disposed on an optical path between the first dichroic mirror 160 and the first display element 175, the second dichroic mirror 180, and the second display. A second capacitor lens unit 190 disposed on an optical path between the elements 195 and a third capacitor lens disposed on an optical path between the second dichroic mirror 180 and the third display element 205. It comprises a unit 200.

Here, the first, second and third condenser lens units 170, 190 and 200 are converging lenses 171, 191 and 201 for converging incident light, and the converging lenses 171 and 191. 201 and the first, second, and third display elements 175 (195, 205) are disposed on an optical path, respectively, so that the first, second, and third display elements 175 (195) are disposed. Diverging lenses 173, 193, and 203 for emitting light directed toward each of the first, second, and third display elements 175, 195, and 205 to match the size of the < RTI ID = 0.0 > .

In this case, the first capacitor lens unit 170 focuses and diverges the light branched from the first dichroic mirror 160 to reduce the width of the incident light. The second and third capacitor lens units 190 and 200 respectively focus and diverge the light branched from the second dichroic mirror 180 to reduce the width of incident light. Therefore, the light incident on the first and second dichroic mirrors 160 and 180 and transmitted through each of the condenser lens units 170, 190 and 200 has a wide width in each of the display elements 175, 195, and 205. Are incident on the first, second, and third display elements 175 (195, 205) in parallel while being reduced to match the size of?).

The projection lens unit 210 is disposed adjacent to another emission surface of the polarization beam splitter 150 to receive incident light of an image corresponding to one screen generated by the three display elements 175, 195, and 205. At the same time, they overlap and project toward the screen.

3 is a schematic view showing an optical arrangement of a reflective project apparatus according to another embodiment of the present invention.

As shown, the reflective project device of the present invention includes a light source 110, a polarizing beam splitter 150 for converting a traveling path of incident light, a first dichroic mirror 160 for splitting incident light according to a wavelength, A second dichroic mirror 180 for transmitting or reflecting daylight diverged from the first dichroic mirror 160 according to a wavelength, and first, second and third display elements 175 and 195 for generating and reflecting an image. 205, condensing means for condensing and diverting light, and a projection lens unit 210 for expanding and projecting the light toward the screen. Here, this embodiment is distinguished from the embodiment described with reference to FIG. 2 in the structure of the condensing means. Therefore, the same reference numerals as those in FIG. 2 have the same function, and thus detailed description thereof will be omitted.

The condensing means includes a converging lens 300 for converging incident light, and first, second and third diverging lenses 310, 320, and 330. The first converging lens 300 is disposed on an optical path between the polarizing beam splitter 150 and the first dichroic mirror 160 to converge incident light. Each of the first, second, and third diverging lenses 310, 320, and 330 may include the first dichroic mirror 160 and the first, second, and third display elements 175, 195, and 205. It is disposed in between to emit incident light to match the size of each display element 175 (195, 205). Therefore, in the reflective project apparatus of FIG. 2, three converging lenses 171 and 191 are disposed and used on optical paths between the dichroic mirrors 160 and 180 and the diverging lenses 173, 193 and 203, respectively. 201 can be reduced to one.

On the other hand, the reflective project device according to the invention preferably further comprises a color correction filter 140 on the optical path between the light source 110 and the polarizing beam splitter 150 to improve color balance and color purity. Can be. In this case, the color correction filter 140 may be a hot mirror to block light in the ultraviolet and infrared regions emitted from the light source.

In addition, by reflecting other light, for example, reflected light, branched from the first dichroic mirror 160, the first display device may be formed to be substantially parallel to daylight, for example, transmitted light, branched from the first dichroic mirror 160. It is preferable to further include a reflective mirror 165 to be incident to the (175). In this case, the optical paths to the display elements 175, 195, and 205 of the light transmitted and reflected by the first dichroic mirror 160 can be made substantially the same while reducing the installation space of the reflective project device. have.

Hereinafter, the operation of the reflective project apparatus according to the present invention will be described with reference to FIGS. 2 and 3.

The light emitted from the light source 110 is incident on the relay lens unit 130 with uniform light while passing through the light mixing means 120, for example, the scrambler 125. The incident light passes through the relay lens unit 130 and expands in width and becomes parallel light. The parallel light is incident on the polarization beam splitter 150 via the color correction filter 140, for example, a hot mirror. Light incident on the polarization beam splitter 150 is transmitted or reflected on the mirror surface 151 according to the polarization component. The effective light passing through the polarization beam splitter 150 is branched to the first dichroic mirror 160 according to the wavelength.

The branched first color light 161, for example, red light, is reflected by the reflection mirror 165 and then passes through the first capacitor lens unit 170 and is incident on the first display element 175. The branched daylight is incident on the second dichroic mirror 180 to reflect the second color light 181, for example, blue light, and then passes through the second capacitor lens unit 190 to be incident on the second display element 195. Color light 183, that is, green light is transmitted. The transmitted green light 183 passes through the third capacitor lens unit 200 and is incident on the third display device 205. At this time, the incident light is condensed by the condensing means according to the present invention and the three display elements 175 and 195 with the width reduced to fit the size of the first, second and third display elements 175, 195 and 205. It is incident on 205, respectively.

Light incident on the three display elements 175, 195, and 205 is polarized by each pixel and reflected. The light reflected from the first, second and third display elements 175, 195 and 205 is reincident to the polarization beam splitter 150. Among the light incident on the polarization beam splitter 150 from each of the display elements 175, 195, and 205, the light whose polarization state is changed by 90 degrees in units of pixels is reflected and superimposed so as to overlap the projection lens unit 210. Is headed. Therefore, the image for each color generated by each of the display elements 175, 195, and 205 is simultaneously projected onto the screen via the projection lens unit 210.

The reflective project apparatus according to the present invention as described above comprises three display elements having first and second dichroic mirrors for selectively transmitting and reflecting the light emitted from the light source for each color and generating an image of each color. By simultaneously projecting the image for each color formed independently on the screen, the utilization efficiency of the light emitted from the light source is theoretically 1/2, so that the amount of light projected on the screen can be increased to improve the brightness of the image.

Claims (9)

A light source for generating and emitting light; A polarization beam splitter which transmits or reflects incident light according to a polarization component to convert a traveling path of the incident light; A first dichroic mirror disposed adjacent to one exit surface of the polarizing beam splitter and splitting incident light according to a wavelength; A second dichroic mirror for transmitting or reflecting daylight branched from the first color mirror according to a wavelength; A first display element for generating and reflecting an image from light diverged from the first dichroic mirror; Second and third display elements for generating and reflecting an image from each light branched from the second dichroic mirror; Condensing means for focusing and diverging light emitted from one exit surface of the polarizing beam splitter to be incident on the first, second, and third display elements while the width thereof is reduced; A projection lens unit disposed adjacent to another exiting surface of the polarizing beam splitter to enlarge and project the light reflected from the first, second and third display elements and whose path is converted by the polarizing beam splitter toward a screen; Reflective project device, characterized in that. The reflective project apparatus according to claim 1, wherein the first and / or second dichroic mirror is plate-shaped. The light emitting device of claim 1, wherein the condensing means is disposed on an optical path between the first dichroic mirror and the first display element, between the second dichroic mirror and the second display element, and between the second dichroic mirror and the third display element, respectively. And first, second, and third condenser lens units for condensing and diverting incident light to reduce the width of the incident light. 4. The apparatus of claim 3, wherein each of the first, second, and third capacitor lens units comprises: a converging lens for converging incident light; And a diverging lens for emitting light directed toward each of the first, second and third display elements to match the size of the first, second and third display elements. The light emitting device of claim 1, further comprising: a focusing lens disposed on an optical path between the light source and the polarizing beam splitter, the focusing lens emitting light emitted from the light source; And a collimating lens disposed on an optical path between the focusing lens and the polarizing beam splitter to focus incident divergent light to become parallel light. The reflective project apparatus according to claim 1, wherein at least one of the first, second and third display elements is a ferroelectric liquid crystal display element. The light source of claim 1, further comprising: a light mixing means disposed on an optical path between the light source and the polarizing beam splitter to diverge / converge or diffusely reflect the light incident from the light source to become uniform light; Reflective project device. 8. The reflective project apparatus according to claim 7, wherein the light mixing means is a rectangular parallelepiped scrambler made of glass having an incident surface and an exit surface perpendicular to the optical path so that the incident light is diffusely reflected to become uniform light. The condensing means of claim 1, further comprising: a converging lens disposed on an optical path between the polarizing beam splitter and the first dichroic mirror to converge incident light; And disposed on the optical paths between the first dichroic mirror and the first display element, between the second dichroic mirror and the second display element, and between the second dichroic mirror and the third display element, respectively. And a first, second and third diverging lens for emitting light directed to each of the first, second and third display elements to match the size of the third display element.

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