KR100457505B1 - Reflection type projector suppressing optical loss and preventing optical dispersion - Google Patents

Abstract

PURPOSE: A reflection type projection apparatus is provided to facilitate optical arrangement of prisms and image generators by excluding a polarizing beam splitter. CONSTITUTION: A first color mirror(131) passes or reflects an incident light based on its wavelength region. A first penta-prism(140) changes a propagation path of the light incident through a first incident surface. A first image generator(145) is implemented around the first penta-prism. The second color mirror(135) passes or reflects the light reflected at the first color mirror based on its wavelength region. A second penta-prism(150) changes a propagation path of the light incident through a second incident surface. A second image generator(155) is implemented around the second penta-prism. A third penta-prism changes a propagation path of the light incident through a third incident surface. A third image generator(165) is implemented around the third penta-prism. A color beam splitter(170) includes first and second mirror surfaces selectively reflecting the light through the first through third penta-prisms based on its wavelength. A projection lens unit(180) magnifies the light from the beam splitter to propagate toward a screen.

Description

Reflective Project Device

The present invention relates to a reflective project apparatus using reflective image generating means, and more particularly, to a reflective project apparatus that can increase the brightness of light projected on a screen by using all the light emitted from a light source.

Generally, a projector 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 projector apparatus is classified into a transmissive type and a reflective type according to the form of the image generating means described above.

1 is a schematic view showing an optical arrangement of a conventional reflective projector device. As shown, a light source 10 for generating and irradiating light, a color wheel 20 for selectively transmitting a predetermined color of incident light, a scrambler 30 for mixing incident light to make uniform light, and a focusing lens ( 32), a collimating lens 34, a polarizing beam splitter 40 for converting the traveling path of incident light, a display element 50 for selectively reflecting incident light and an incident light screen (not shown) And a projection lens unit (60) for projecting on.

The light source 10 includes a lamp 11 for generating light such as metal halide, xenon, and the like, and a reflector 13 for reflecting the light emitted from the lamp 11 and guiding the path of the light. The color wheel 20 is rotatably installed by the driving motor 21 on the optical path between the light source 10 and the scrambler 30, and is red (R), green (G), and blue (B). The three colors are evenly distributed throughout the wheel. According to the response speed of the display device 50, any one of red, green, and blue of the color wheel 20 is disposed on the optical path, and three colors of red, green, and blue are sequentially stacked to form a screen. do.

The scrambler 30 is made to be uniform light by mixing the incident light by the diffuse reflection. The focusing lens 32 focuses and diverges the light passing through the scrambler 30 to enlarge the transmission width of the 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. To convert That is, the light incident from the light source 10 is selectively transmitted or reflected depending on the polarization component, that is, P polarization or S polarization. 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 ferroelectric liquid crystal display (FLCD) having excellent response speed characteristics having a two-dimensional array structure is employed. The display element 50 has a plurality of reflective regions of a two-dimensional array structure, and is driven independently to form an image by modulating the polarization direction of incident light.

Light incident on the display device 50 is reflected back to the polarizing beam splitter 40. In this case, the light re-injected into the polarization beam splitter 40 is changed by the display element 50 in the polarization direction by 90 degrees, and is totally reflected on the mirror surface 41 of the polarization beam splitter 40 so as to project the lens. To the unit (60). This light passes through the projection lens unit 60 and is projected onto a screen (not shown).

As described above, the conventional reflective project device configured to implement a color by having a color wheel 20 on the optical path, thereby sequentially irradiating the three colors to the screen to implement a screen. Therefore, in theory, since it has a light efficiency corresponding to 1/3 of the amount of light emitted from the light source, there is a problem that the brightness is lowered.

In view of the above, the present applicant has applied for a reflection of a structure employing a plurality of critical angle prisms through Korean Patent Application No. 13025 (Invention: Reflective Project Apparatus, Filed Date: April 9, 1997) in 1997. We have proposed a type project device.

The proposed reflective project device has the advantage of greatly increasing the light utilization efficiency by using all the light emitted from the light source. However, if the optical path is distorted due to the assembly or processing tolerance of the critical angle prism described above, there is a fear that a desired total reflection does not occur in the critical angle prism, resulting in light loss.

In addition, since the illumination light is not incident in the vertical direction with respect to the incident surface of the critical angle prism, there is a problem in that light scattering phenomenon occurs in the incident surface.

Accordingly, the present invention has been made in view of the above-described problems, so that three screens are simultaneously irradiated to the screen to improve the light efficiency, thereby realizing one screen, increasing the brightness of the screen, suppressing light loss, and dispersing light. Its purpose is to provide a reflective project apparatus in which a phenomenon does not occur.

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 the main parts of the drawings>

110.Light 111.Lamp

113 Reflector 120,120 '... Light mixing means

121,122 Paris eye lens 123,126 Collimating lens

125 Scrambler 131

132,133,134 ... reflective mirror 135 ... Secondary mirror

140 First Pentaprism 141 First Entrance

142 ... First reflecting surface 143 ... First exiting surface

145,145 '... 1st generation means 146 ... 1st polarizer

147 ... First reflective liquid crystal display 148 ... First analyzer

149.First movable mirror 150 ... Second pentaprism

151 ... second entrance plane 152 ... second reflection plane

153 ... 2nd exit 155,155 '... 2nd image generating means

156 Second Polarizer 157 Second Reflective Liquid Crystal Display

158 2nd analyzer 159 2nd movable mirror device

160 ... The Third Pentaprism 161 ... The Third Entrance

162 ... 3rd reflector 163 ... 3rd exit

165,165 '... 3rd generation means 166 ... 3rd polarizer

167 3rd reflection type liquid crystal display element 168 3rd analyzer

169 ... 3rd movable mirror unit 170 ... Different beam splitter

180 ... projection lens unit

In order to achieve the above object, the present invention provides a light source for generating and projecting light; A first dichroic mirror disposed on an optical path and transmitting and reflecting incident light according to a wavelength region; A first pentaprism having a first incidence surface disposed so that light transmitted through the first dichroic mirror is vertically incident, and converting a traveling path of light incident through the first incidence surface; First image generating means disposed around the first pentaprism for generating an image from incident light passing through the first pentaprism and reflecting it to another optical path; A second dichroic mirror for transmitting and reflecting light reflected from the first dichroic mirror according to a wavelength region; A second pentaprism having a second incidence surface arranged to vertically incident light reflected from the second dichroic mirror, and converting a traveling path of light incident through the second incidence surface; Second image generating means disposed around the second pentaprism to generate an image from incident light passing through the second pentaprism and reflect it to another optical path; A third pentaprism having a third incidence surface disposed so that light transmitted through the second dichroic mirror is vertically incident, and converting a traveling path of the light incident through the third incidence surface; Third image generating means disposed around the third pentaprism to generate an image from incident light passing through the third pentaprism and reflect it to another optical path; A dichroic beam splitter having first and second mirror surfaces selectively transmitting or reflecting light according to a wavelength such that light incident through the first, second and third pentaprisms is emitted in one direction; A projection lens unit for extending and transmitting the light incident from the dichroic beam splitter toward the screen; It is characterized by including.

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

Referring to FIG. 2, the reflective project device of the present invention includes a light source 110 for generating and projecting light, and first and second dichroic mirrors disposed on an optical path to transmit and reflect incident light according to a wavelength region thereof. 131 and 135, first, second and third pentaprism 140 and 150 and 160 for converting a traveling path of incident light and first, second and third image generation for generating an image from the incident light. A dichroic beam splitter 170 for causing light incident through the means 145, 155, 165 and the first, second, and third pentaprism 140, 150, 160 to exit in one direction. And a projection lens unit 180 that enlarges and projects the light incident from the dichroic beam splitter 170.

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 may be an ellipsoidal mirror having the position of the lamp 111 as one focal point and the point where the light is focused as another focal point, or the lamp 111 having the position of the lamp 111 as one focal point. The light emitted and reflected by the reflector 113 may be a parabolic mirror in which parallel light is formed.

On the optical path between the light source 110 and the first dichroic mirror 131, the light mixing means 120, 120 'to diverge / converge or diffuse the light incident from the light source 110 to become uniform light It is preferable that it is further provided. 2 is a focusing lens for focusing light transmitted through the first and second fly-eye lenses 121 and 122 and the second fly-eye lens 122 disposed adjacent to each other by the light mixing means 120. An example including (123) is shown. In this case, it is preferable that a parabolic mirror is used as the reflector 113.

In addition, as shown in FIG. 3, as the light mixing means 120 ′, a scrambler 125 and a focusing lens 126 may be employed to diffuse the incident light into uniform light. The scrambler 125 is a rectangular parallelepiped glass having an entrance plane and an exit plane perpendicular to the optical path. As described above, when the scrambler 125 is employed, the reflector 113 is preferably an ellipsoid. The focusing lens 126 is disposed on an optical path between the scrambler 125 and the first dichroic mirror 131 to focus incident light.

The first dichroic mirror 131 selectively transmits and reflects light incident from the light source 110 according to a wavelength region. For example, the first dichroic mirror 131 is manufactured by dielectric coating, and reflects light corresponding to green (G) and red (R), and transmits light corresponding to blue (B). The light transmitted through the first dichroic mirror 131 is reflected by the first reflecting mirror 132 and the second reflecting mirror 133, and then is transmitted to the first pentaprism 140 and the first image generating means 145. Incident.

The light reflected by the first dichroic mirror 131 is reflected by the third reflecting mirror 134 and then incident on the second dichroic mirror 135. The second dichroic mirror 135 selectively transmits and reflects incident light according to a wavelength region. For example, the second dichroic mirror 135 reflects light corresponding to green (G) and transmits light corresponding to red (R). The light reflected from the second dichroic mirror 135 is incident on the second pentaprism 150 and the second image generating means 155. The light transmitted through the second dichroic mirror 135 is incident on the third pentaprism 160 and the third image generating unit 165.

The first pentaprism 140 converts a traveling path of the light incident through the first dichroic mirror 131. The first image generating means 145 generates an image from the light incident through the first pentaprism 150.

The first pentaprism 140 may include a first incident surface 141 and a light incident through the first incident surface 141 so that the light transmitted through the first dichroic mirror 131 is vertically incident on the first pentaprism 140. The first exit surface disposed in parallel with the first reflection surface 142 and the first surface 171 of the dichroic beam splitter 170 so as to be inclined with respect to the first incident surface 141 so as to reflect different light paths. Has a face 143.

The first image generating means 145 includes a first polarizer 146, a first reflective liquid crystal display 147, and a first analyzer 148. The first reflection type liquid crystal display device 147 is usually composed of a liquid crystal display device having excellent response speed characteristics such as a ferroelectric liquid crystal display (FLCD).

The first reflection type liquid crystal display 147 is disposed to face the first surface 171 of the first pentaprism 140 to selectively receive light reflected by the first reflection surface 142. The light is reflected toward the first exit surface 143. That is, the first reflection type liquid crystal display 147 has a plurality of pixels that are driven independently of each other in the two-dimensional array structure. Each pixel causes the incident light to be linearly polarized in the same polarization direction or linearly polarized light in the other polarization direction, and reflects the incident light toward the first emission surface 143. The first polarizer 146 is disposed to face the first incident surface 141 to transmit only light having a predetermined polarization. The first analyzer 148 is disposed on an optical path between the first emission surface 143 and the first surface 171 of the dichroic beam splitter 170, and the first reflective liquid crystal display device. The light reflected by 147 and transmitted through the first exit surface 143 is selectively transmitted according to the polarization direction. The light transmitted through the first analyzer 148 has a color of light transmitted through the first dichroic mirror 131, for example, a blue (B) color, and includes an image of the blue.

The second pentaprism 150 is disposed on an optical path between the second dichroic mirror 135 and the second surface 172 of the dichroic beam splitter 170 to be reflected by the second dichroic mirror 135. The traveling path of the light is converted to the received light. Here, the second pentaprism 150 has a second light incident surface 151 to which light reflected from the second dichroic mirror 135 is incident, and light incident from the second light incident surface 151 toward another light path. And a second reflecting surface 152 for reflecting and a second emitting surface 153 disposed to face the dichroic beam splitter 170. Since the role and optical arrangement of each of the second pentaprism 150 are substantially the same as each of the first pentaprism 140, detailed description thereof will be omitted.

The second image generating means 155 includes a second polarizer 156, a second reflective liquid crystal display 157, and a second analyzer 157, each of which serves as an optical arrangement. Since substantially the same as the first image generating means 145, detailed description thereof will be omitted.

The third pentaprism 160 is disposed on an optical path between the second dichroic mirror 135 and the third surface 173 of the dichroic beam splitter 170 to transmit the second dichroic mirror 135. It converts the path of light for one light. Here, the third pentaprism 160 has a third light incident surface 161 through which the light transmitted through the second dichroic mirror 135 is incident, and light incident from the third light incident surface 161 toward another light path. A third reflecting surface 162 to reflect, and a third exit surface 163 disposed to face the third surface 173 of the dichroic beam splitter 170. Since the role and optical arrangement of the third pentaprism 160 is substantially the same as each of the first pentaprism 140, detailed description thereof will be omitted.

The third image generating means 165 includes a third polarizer 166, a third reflective liquid crystal display 167, and a third analyzer 168, and their respective roles and optical arrangements. Since substantially the same as the first image generating means 145, detailed description thereof will be omitted.

The dichroic beam splitter 170 has three entrance planes 171, 172, 173 and one exit plane 174. Each of the three incident surfaces 171, 172, 173 faces each of the first, second, and third pentaprisms 140, 150, 160, and each of the incident surfaces 171, 172, 173. The traveling path of the incident light is converted so that the light incident through the N-side heads toward the one exit surface 174. To this end, the dichroic beam splitter 170 has first and second mirror surfaces 176 and 177 for selectively transmitting or reflecting light depending on the wavelength. The first mirror surface 176 is coated to transmit and reflect according to the wavelength region to reflect the light incident through the first pentaprism 140, and the second and third pentaprisms 150 and 160. The light incident through the light is transmitted. The second mirror surface 177 is coated to transmit and reflect according to the wavelength region to transmit the light passing through the first and second pentaprisms 140 and 150, and passes through the third pentaprism 160. One light reflects. As described above, since the dichroic beam splitter 170 includes first and second mirror surfaces 176 and 177, the light incident from each of the three incident surfaces 171, 172, and 173 is one exit surface. 174 exits.

The projection lens unit 180 is disposed between the dichroic beam splitter 170 and a screen (not shown) to enlarge and project the light incident from the dichroic beam splitter 170 toward the screen.

Hereinafter, with reference to the accompanying Figure 2 will be described the operation of the reflective project device according to an embodiment of the present invention.

Referring to FIG. 2, the light irradiated from the light source 110 passes through the light mixing means 120, for example, the first and second fly-eye lenses 121 and 122 and the focusing lens 123, so that uniform light is generated. Incident on the first dichroic mirror 131. Light incident on the first dichroic mirror 131 is selectively transmitted and reflected according to the wavelength region. The light transmitted through the first dichroic mirror 131 is incident on the first image generating means 145 via the first pentaprism 140. The first image generating unit 140 selects a reflection direction or a polarization direction of the incident light according to each pixel area to form an image corresponding to the color of the incident light, and reflects it toward the dichroic beam splitter 170.

The light reflected by the first dichroic mirror 131 is incident on the second dichroic mirror 135. The second dichroic mirror 135 selectively transmits and reflects incident light according to the wavelength region. The reflected light is incident on the second surface 172 of the dichroic beam splitter 170 via the second pentaprism 150 and the second image generating means 155. The light transmitted through the second dichroic mirror 135 is incident on the third surface 173 of the dichroic beam splitter 170 via the third pentaprism 160 and the third image generating means 165. do.

The light corresponding to each color incident on the dichroic beam splitter 170 is selectively transmitted and reflected on the first and second mirror surfaces 176 and 177 and overlaps each pixel for each projection lens unit 180. Pass through to the screen.

Referring to Figure 3, a reflective project apparatus according to another embodiment of the present invention will be described in detail. Here, the same reference numerals as in the above-described drawings are the same members having the same function.

According to a feature of this embodiment, the first, second and third movable mirror apparatuses (hereinafter referred to as first, second and third image generating means 145 ', 155' and 165 'for generating an image from incident light) DMD) 149, 159, and 169 are employed.

The first movable mirror apparatus 149 is positioned to face the first pentaprism 140 and includes a plurality of reflective mirrors (not shown) having a two-dimensional array structure. Each reflecting mirror is independently hinged to have various reflection angles for incident light. Since the structure of the above-mentioned DMD is widely known, its detailed description is omitted.

As described above, the reflective project device according to the embodiment of the present invention has a first, second and third pentaprism, and uses a first, second and third image generating means to display a color screen. By simultaneously superimposing each constituent color, the brightness of the screen can be greatly increased. In addition, optical alignment may be facilitated by eliminating the use of a polarizing beam splitter that is sensitive to the angle of incidence of light when converting the optical path according to polarization. In addition, since the light incidence plane of each pentaprism is disposed perpendicular to the incident light, light scattering does not occur in the incidence plane, thereby fundamentally suppressing light loss due to dispersion.

Claims (10)

A light source for generating and projecting light; A first dichroic mirror disposed on an optical path and transmitting and reflecting incident light according to a wavelength region; A first pentaprism having a first incidence surface disposed so that light transmitted through the first dichroic mirror is vertically incident, and converting a traveling path of light incident through the first incidence surface; First image generating means disposed around the first pentaprism for generating an image from incident light passing through the first pentaprism and reflecting it to another optical path; A second dichroic mirror for transmitting and reflecting light reflected from the first dichroic mirror according to a wavelength region; A second pentaprism having a second incidence surface arranged to vertically incident light reflected from the second dichroic mirror, and converting a traveling path of light incident through the second incidence surface; Second image generating means disposed around the second pentaprism to generate an image from incident light passing through the second pentaprism and reflect it to another optical path; A third pentaprism having a third incidence surface disposed so that light transmitted through the second dichroic mirror is vertically incident, and converting a traveling path of the light incident through the third incidence surface; Third image generating means disposed around the third pentaprism to generate an image from incident light passing through the third pentaprism and reflect it to another optical path; A dichroic beam splitter having first and second mirror surfaces selectively transmitting or reflecting light according to a wavelength such that light incident through the first, second and third pentaprisms is emitted in one direction; A projection lens unit for extending and transmitting the light incident from the dichroic beam splitter toward the screen; Reflective project device comprising a. The method of claim 1, wherein the first image generating means A first polarizer for transmitting only light of a predetermined polarization component among incident light; A first reflection type liquid crystal display device which causes the incident light to be light having a polarization direction independently selected according to each pixel region and reflects the incident light; And a first analyzer disposed on an optical path between the first pentaprism and the dichroic beam splitter to transmit light in one polarization direction selected by the first reflection type liquid crystal display device. Mold project device. The method of claim 1, wherein the first image generating means Reflective project device, characterized in that the movable mirror device having a two-dimensional array structure and includes a plurality of reflective mirrors each independently driven. The method of claim 1, wherein the second image generating means A second polarizer for transmitting only light of a predetermined polarization component among incident light; A second reflection type liquid crystal display element which causes the incident light to be light having a polarization direction independently selected according to each pixel region and reflects the incident light; And a second analyzer disposed on an optical path between the second pentaprism and the dichroic beam splitter to transmit light in one polarization direction selected by the second reflection type liquid crystal display device. Mold project device. The method of claim 1, wherein the second image generating means Reflective project device, characterized in that the movable mirror device having a two-dimensional array structure and includes a plurality of reflective mirrors each independently driven. The method of claim 1, wherein the third image generating means A third polarizer for transmitting only light of a predetermined polarization component among incident light; A third reflection type liquid crystal display device which causes the incident light to be light having a polarization direction independently selected according to each pixel region, and reflects the incident light; And a third analyzer disposed on an optical path between the third pentaprism and the dichroic beam splitter to transmit light in one polarization direction selected by the third reflective liquid crystal display device. Mold project device. The method of claim 1, wherein the third image generating means Reflective project device, characterized in that the movable mirror device having a two-dimensional array structure and includes a plurality of reflective mirrors each independently driven. The light mixing means according to any one of claims 1 to 7, wherein the light mixing means further diffuses / converges or diffusely reflects the light incident from the light source toward the light path between the light source and the first dichroic mirror so as to be uniform light. Reflective project device, characterized in that provided. 10. The method of claim 8, wherein the light mixing means has a plurality of convex portions formed on the entrance surface and / or the emission surface to focus the incident light, respectively, the first and second fly-eye lens disposed adjacent to each other, and the second fly-eye Reflective project device comprising a focusing lens for focusing the light transmitted through the lens to be parallel light. 9. The reflective project apparatus according to claim 8, 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.

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