KR101100352B1 - Micro projection apparatus - Google Patents

Abstract

By using an illumination plate instead of an existing illumination lens, a color separation synthesis system, and an integrator, it is possible to reduce the space for arranging the illumination optical system, thereby providing a micro-projection apparatus capable of realizing a microscopic microprojection apparatus. Micro-projection apparatus, the light emitting diode (LED) or laser diode (LD) light source for emitting light separated into R, G, B; An illumination plate having a plurality of fine patterns for reflecting the light incident from the light source upwardly without being emitted to the outside according to the total internal reflection condition; A beam splitter for separating light emitted through the lighting plate; A reflective micro display disposed at a distance from the lighting plate and configured to implement an image with light separated by a beam splitter; And a projection lens for expanding and projecting a light beam corresponding to an image implemented in the reflective micro display on the screen, wherein light emitted from the lighting plate is uniformly illuminated on the reflective micro display by varying the shape and pattern density of the fine pattern. It is characterized by.

Micro Projection Units, Light Plates, Reflective Micro Displays, LCOS, DMD

Description

Micro projection apparatus

The present invention relates to a projection apparatus, and more particularly, to a microscopic micro projection apparatus capable of realizing a microscopic microprojection apparatus by reducing the arrangement space of the illumination optical system.

In general, a projection device (projector) is used to provide a large image by enlarging and projecting an image implemented by a display element onto a screen. Such a projector may include a light source for emitting light, an illumination optical system for focusing light emitted from the light source, a display device for implementing an image with light provided from the illumination optical system, and a light beam for forming an image implemented in the display device. And a projection optical system for projecting.

Such a projector focuses the incident light separated into R, G, and B through the illumination optical system, implements the focused light by using a display element, and expands the light implemented in the display element on the screen through the projection optical system. Will be projected.

On the other hand, such a projector is classified into a reflective projector and a projection projector according to whether the light beam is reflected or transmitted through the image display panel. In addition, the projector may be classified into a single plate type, two plate type, and three plate type projectors according to the number of image display panels used. In addition, according to the type of light source may be divided into a projector using a lamp light source and a projector using a light emitting diode or a laser light source.

By the way, a projector using a lamp light source is very large and difficult to carry. In order to overcome this problem, a recent development of a projector using a light emitting diode or a laser light source has been progressed.

On the other hand, portable multimedia devices such as digital cameras, digital camcorders, PMPs, PSPs, laptop computers, and mobile phones have been widely used in recent years, and as the utilization of such portable multimedia devices increases, there are many cases of using them with others. In particular, since the portable multimedia device has good mobility, the portability and mobility of the projector should also be good to increase the utilization of the portable multimedia device. Therefore, in order to increase portability, the necessity of manufacturing a projector as a micro projector that can be stored in a pocket is increasing.

1 is a diagram illustrating a micro projection apparatus according to the prior art.

Referring to FIG. 1, the microprojection apparatus 10 according to the related art includes a red (R) LED 11R, a green (G) LED 11G, a blue (B) LED 11B, and a reflective mirror 12. ), Illumination lenses 13a, 13b, beam splitter 14, reflective micro display 15, and projection lenses 16a, 16b, 16c, 16d.

The light beam forming the image in the micro-projection apparatus 10 is projected onto the screen / wall 20. In this case, in the microprojection apparatus 10 according to the related art, the illumination lenses 13a and 13b should be disposed in a predetermined space on the side of the beam splitter 14. That is, the R, G, and B light sources 11R, 11G, and 11B should be incident into the beam splitter 14 through the illumination lenses 13a and 13b, and the illumination lenses 13a and 13b are directed to the side of the beam splitter 14. When placed on the floor, significant space is required, as indicated by reference numeral L. FIG.

On the other hand, as a prior art related to a micro-projector, Korean Patent Application No. 2006-0084830 (application date: September 04, 2006) discloses the invention named "micro projector" bar, digital camera, digital camcorder, The present invention relates to a miniature micro projector that is connected to a portable multimedia player (PMP), a laptop computer, a mobile phone, and displays an enlarged image on an external screen, and is easy to carry, and will be described with reference to FIGS. 2 and 3.

FIG. 2 is a perspective view illustrating a microprojector according to the related art, and FIG. 3 is a view showing a schematic arrangement of an optical system viewed from the side of the microprojector shown in FIG. 2.

Referring to FIG. 2, the microprojector 30 according to the related art has a hexahedron shape as a whole, and an exit port 50 through which light beams are emitted to an external screen is disposed above the front surface of the microprojector 30. In addition, a menu button unit 40 for operating the projector 30 is disposed on the top surface of the micro projector 30. In addition, an input port for receiving an image signal from a portable multimedia device may be disposed at the rear of the micro projector 30.

Referring to FIG. 3, the optical system of the micro projector 30 according to the related art is largely divided into a projection optical system 31 and an illumination optical system 32.

The illumination optical system 32 includes a G light source 41, an R light source 42, a B light source 43, first to third focusing lenses 44, 45, and 46, a micro fly's eye lens 52, and lambda / 2. Filter 33, first to third mirrors 47, 48, 49, reflective mirrors 51, homogenizing means 53, 54, polarizing beam splitters (PBSs) 55 and image display panels 34 may be included.

At this time, the equalization means 53 and 54 are composed of the fourth focusing lens 53 and the collimation lens 54, and the light beam passing through the equalization means 53 and 54 is, in principle, the incident surface (PBS 55). Should be perpendicular to 55a). In reality, however, a skew ray is generated that is not perpendicular to the incident surface 55a, and the skew ray is reflected from the reflective surface 55b of the PBS 55 with the polarization direction slightly rotated. To correct this, the λ / 4 filter 56 may be additionally disposed in the light beam path between the PBS 55 and the image display panel 34. In addition, a polarizer 57 may be additionally disposed between the PBS 55 and the projection optical system 31.

The projection optical system 31 includes a series of lenses through which the light beam passing through the image display panel 34 passes.

In detail, the light source is a laser light source, and includes a G light source 41, an R light source 42, and a B light source 43. For example, the G light source 41 may be a diode pumping solid state laser. DPSS), and the R light source 42 and the B light source 43 may be laser diodes (LDs). The LD and DPSS have advantages in that they are smaller in size than other laser light sources, and the G light beam emitted from the DPSS has a good straightness compared to the R light beam and the B light beam emitted from the LD, so the width of the light beam is small.

The micro-projector 30 includes R, G, B laser light sources and LCOS panels, and is for optimizing the placement of the illumination and projection optics, but includes the first to third focusing lenses 44, 45, 46, and the like. Since the arrangement space is required, there is a space limitation. That is, since the first to third focusing lenses 44, 45, and 46 must be disposed in a predetermined space, there is a limitation in reducing the size of the illumination optical system, and thus there is a problem in that the miniaturization of the micro projector is limited.

SUMMARY OF THE INVENTION The present invention has been made in an effort to provide a micro-projection apparatus capable of reducing the space for arranging an illumination optical system by using an illumination plate instead of an existing illumination lens.

Another technical problem to be solved by the present invention is that the light distribution is not uniform on the exit surface of the illumination plate, but on the reflection type micro display surface, the micro-projection apparatus that can provide a uniform brightness illumination by configuring It is to provide.

As a means for achieving the above-described technical problem, the micro-projection apparatus according to the present invention, in the micro-projection apparatus for projecting an image through a reflective micro display, a light emitting diode for emitting light separated by R, G, B (LED) or laser diode (LD) light sources; An illumination plate having a plurality of fine patterns for reflecting the light incident from the light source upwardly without being emitted to the outside according to the total internal reflection condition; A beam splitter for separating light emitted through the lighting plate; A reflective micro display disposed at a distance from the lighting plate and configured to implement an image with light separated through the beam splitter; And a projection lens configured to enlarge and project a light beam corresponding to an image implemented in the reflective micro display on a screen, wherein light emitted from the lighting plate is changed by varying the shape and pattern density of the fine pattern. It is characterized in that it is uniformly illuminated on.

Here, the fine pattern of the lighting plate may be formed on the lower surface of the lighting plate, the upper surface of the lighting plate, or may be simultaneously formed on the lower surface and the upper surface of the lighting plate.

Herein, the shape of the fine pattern may be selected from sphere, prism, pyramid, cone cylinder and horizontal cylinder.

Here, the light emitting surface of the illumination plate is formed so that the light distribution is not uniform, and characterized in that configured to have a uniform light distribution on the reflective micro display surface.

On the other hand, as another means for achieving the above technical problem, the micro-projection apparatus according to the present invention, in the micro-projection apparatus for projecting an image through a polarizing beam splitter (PBS), separated into R, G, B Light emitting diode (LED) or laser diode (LD) light sources for emitting light; An illumination plate having a plurality of fine patterns for reflecting the light incident from the light source upwardly without being emitted to the outside according to the total internal reflection condition; A polarizing beam splitter (PBS) for dividing the light emitted through the illumination plate into a first polarization component and a second polarization component; A liquid crystal display device (LCOS) disposed at a predetermined distance from the illumination plate, utilizing a liquid crystal in a reflection mode, and implementing an image with light split through the polarization beam splitter; And a projection lens configured to enlarge and project a light beam corresponding to an image implemented in the silicon liquid crystal display (LCOS) onto a screen, wherein light emitted from the illumination plate is changed by varying the shape and pattern density of the fine pattern. It is characterized in that it is uniformly illuminated on the liquid crystal display (LCOS).

Here, the micro-projection apparatus according to the present invention is implemented in the form of a thin parallel conductor array and is inserted between the illumination plate and the polarizing beam splitter (PBS) to reflect light of orthogonal polarization while transmitting light of specific polarization. It may further comprise a wire grid polarizer (WGP).

Here, the micro-projection apparatus according to the present invention, as a reflective polarizer, a dual brightness enhancement film inserted between the illumination plate and the polarizing beam splitter (PBS) to improve the brightness of the light emitted from the illumination plate (Dual Brightness Enhancement) Film: DBEF) may be further included.

Here, the fine pattern of the lighting plate may be formed on the lower surface of the lighting plate, the upper surface of the lighting plate, or may be simultaneously formed on the lower surface and the upper surface of the lighting plate.

Here, the shape of the fine pattern may be selected from spherical, prismatic, pyramid, conical cylindrical and horizontal cylindrical.

Here, the light emitting surface of the illumination plate is formed so that the light distribution is not uniform, and the silicon liquid crystal display (LCOS) in the surface is characterized in that configured to have a uniform light distribution.

On the other hand, as another means for achieving the above-described technical problem, the micro-projection apparatus according to the present invention, in the micro-projection apparatus for projecting an image through a digital micromirror element (DMD), separated into R, G, B A light emitting diode (LED) or laser diode (LD) light source that emits the emitted light; An illumination plate having a plurality of fine patterns for reflecting the light incident from the light source upwardly without being emitted to the outside according to the total internal reflection condition; A total internal reflection that is disposed at a distance from the illumination plate, and has a surface that internally reflects light at some angle and passes light at another angle, and separates light provided from the illumination plate from image light reflected from the DMD ( Total Internal Reflection (TIR) prism; A digital micro-mirror device (DMD) for realizing an image with light separated by the total internal reflection (TIR) prism; And a projection lens configured to enlarge and project a light beam corresponding to an image implemented in the digital micromirror device (DMD) onto a screen, wherein light emitted from the illumination plate is changed by varying the shape and pattern density of the fine pattern. It is characterized in that it is uniformly illuminated on the micromirror device (DMD).

Here, the fine pattern of the lighting plate may be formed on the lower surface of the lighting plate, the upper surface of the lighting plate, or may be simultaneously formed on the lower surface and the upper surface of the lighting plate.

Here, the shape of the fine pattern may be selected from spherical, prismatic, pyramid, conical cylindrical and horizontal cylindrical.

Here, the light emitting surface of the illumination plate is formed so that the light distribution is not uniform, and characterized in that configured to have a uniform light distribution on the digital micromirror element (DMD) surface.

According to the present invention, by using an illumination plate instead of an existing illumination lens, a color separation synthesis system, and an integrator, it is possible to reduce the layout space of the illumination optical system, thereby realizing a compact micro-projection apparatus.

According to the present invention, the light distribution is not uniform on the exit surface of the lighting plate, but by providing the light distribution uniform on the reflective micro display surface, it is possible to provide uniform brightness illumination.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention, and like reference numerals designate like parts throughout the specification.

Throughout the specification, when a part is said to "include" a certain component, it means that it can further include other components, without excluding other components unless specifically stated otherwise. Also, the term "part" or the like, as described in the specification, means a unit for processing at least one function or operation, and may be implemented by hardware, software, or a combination of hardware and software.

First, a conventional micro display concept will be described.

Recently, as the display market shows a technology trend of increasing resolution and decreasing screen size, micro display technology is also evolving day by day. In the display sector, small and high-definition displays having a small diagonal screen of 1 inch or less and having a resolution required for an information display device are called micro displays. Such micro displays can be broadly classified into a transmissive type, a reflective type, and a light emitting type.

The typical transmissive type is TFT LCD using high temperature polysilicon and SOI (Silicon On Insulator) using silicon wafer. Also, the reflective type uses silicon wafer as a substrate and the pixel electrode uses metal electrode with good reflectance. There is a liquid crystal on display (LCOS) that utilizes liquid crystal as a reflection mode, or a digital micro-mirror display (DMD) that adjusts the reflection angle by moving fine metal electrodes fabricated on a substrate. In addition, there is a grating light valve (GLV) that constitutes a reflective diffraction grating that can be electrically adjusted on a pixel basis. In the light emitting type, a light emitting layer is formed on a silicon substrate or a switching array substrate made of polysilicon to emit light by itself, and organic EL, inorganic EL, and the like are used.

The main direction this microdisplay is heading is to develop optical infrastructure and essential functions for moving to smaller pixels, smaller imaging devices, and hence lower cost display devices.

On the other hand, as an embodiment of the present invention, by using an illumination plate instead of the existing illumination lens, it is possible to reduce the arrangement space of the illumination optical system, and also to make the light distribution uneven at the exit surface of the illumination plate, the reflective micro display In the aspect, a micro-projection apparatus is provided which can provide uniform brightness illumination by configuring to have a uniform light distribution.

4 is a diagram illustrating a micro-projection apparatus according to the first embodiment of the present invention, and FIG. 5 is a block diagram of the micro-projection apparatus according to the first embodiment of the present invention.

4 and 5, the micro-projection apparatus 100 according to the first embodiment of the present invention includes a light emitting diode (LED) light source 110, an illumination plate 120, and a beam splitter. 130, a reflective micro display 140, and projection lenses 150a to 150d.

The LED light source 110 emits light separated into R, G, and B to enter. At this time, the LED light source 110 is disposed to be incident to the side of the lighting plate (120). In this case, a laser diode LD may be used instead of the LED light source 110.

The illumination plate 120 is formed with a plurality of fine patterns, reflecting the light incident from the LED light source 110 to the top without emitting to the outside according to the total internal reflection conditions. In this case, the light emitted from the lighting plate 120 is uniformly illuminated on the reflective micro display 140 by varying the shape and pattern density of the fine pattern. Here, the fine pattern of the lighting plate 120 is formed on the lower surface of the lighting plate 120, or formed on the upper surface of the lighting plate 120, or the lower surface and the upper surface of the lighting plate 120 At the same time, the shape of the fine pattern may be selected from spheres, prisms, pyramids, cone cylinders and horizontal cylinders. Can be, but is not limited to.

In addition, the light distribution surface of the illumination plate 120 may be formed so that the light distribution is not uniform, and may have a uniform light distribution on the reflective micro display 140 surface.

The beam splitter 130 separates the light emitted through the lighting plate 120.

The reflective micro display 140 is disposed at a predetermined distance from the lighting plate 110 and implements an image with light separated through the beam splitter 130.

A plurality of lenses are arranged in the projection lenses 150a to 150d to enlarge and project a light beam corresponding to the image implemented in the reflective micro display 140 onto the screen / wall 600.

FIG. 6 is a diagram illustrating an LED light source in the micro-projection apparatus shown in FIG. 3.

Referring to FIG. 6, the LED light source is composed of a red LED 110R, a green LED 110G, and a blue LED 120B, respectively, and has a side surface on a micro 3D patterned surface in the lighting plate 120. Incident in a direction.

FIG. 7 is a diagram illustrating various lighting plates in the micro-projection apparatus shown in FIG. 3.

The illumination plate 120 of the micro-projection apparatus shown in FIG. 3 described above is formed with a micro 3D patterned surface, for example, as shown in a) to e) of FIG. (Sphere) lighting plate 120a, prismatic lighting plate 120b, pyramid lighting plate 120c, conical cylinder lighting plate 120d and horizontal cylinder ) May be a lighting plate 120e.

As a result, the micro-projection apparatus 100 according to the first embodiment of the present invention can reduce the space for arranging the illumination optical system by using the illumination plate 120 instead of the existing illumination lens, thereby implementing a micro-projection apparatus. In addition, the light distribution may not be uniform on the exit surface of the illumination plate 120, and the uniform light distribution may be provided on the reflective micro display 140 surface to provide uniform brightness illumination.

Meanwhile, FIGS. 8A to 8C are diagrams illustrating operating principles of the lighting plate according to the embodiment of the present invention, and FIG. 8A shows that the fine pattern 121a is formed on the upper surface of the lighting plate 120, and FIG. 8B. Indicates that the fine pattern 121b is formed on the lower surface of the lighting plate 120, and FIG. 8C shows that the fine patterns 121a and 121b are simultaneously formed on the upper surface and the lower surface of the lighting plate 120, respectively.

8A to 8C, light emitted from the LED light source 110 is incident on the side surface of the lighting plate 120, which is a flat plate optical element such as optical glass or optical plastic. Thereafter, the light incident on the illumination plate 120 proceeds to the interior of the illumination plate 120, and the light that meets the interface with different optical refractive indices such as an upper surface or a lower surface of the illumination plate 120 is subjected to internal total reflection conditions. Accordingly, the light does not exit to the outside of the lighting plate 120 through the upper or lower portion of the lighting plate 120 is reflected.

At this time, the inclined or curved fine patterns 121a and 121b are disposed on the upper or lower portion of the lighting plate 120 in the direction in which the reflective micro display 140 is disposed, as shown in FIGS. 8A to 8C. When the angle of incidence is greater than the total reflection condition at the interface, the angle incident on the interface at the angle of incidence exceeds the total reflection condition, so that the light exits from the upper portion of the illumination plate 120 to reflect. Will be joined. Here, instead of the reflective micro display 140 may be implemented by LCOS or DMD.

In this case, by varying the shape and pattern density of the fine patterns 121a and 121b formed on the lighting plate 120, the fine pattern (eg, the light emitted from the lighting plate 120 is uniformly illuminated on the micro display 140). The shape and pattern density of 121a, 121b) can be comprised. Here, the shape of the fine patterns 121a and 121b may be spherical, prismatic, pyramid, conical cylinder, and horizontal cylinder type as shown in FIG. Horizontal cylinder), but is not limited thereto.

Meanwhile, FIG. 9 is a diagram illustrating an illumination plate fine pattern density, an illumination plate brightness distribution, and an illumination distribution illuminated on a display according to an embodiment of the present invention.

The fine pattern density distribution of the illumination plate illustrated in FIG. 9 a may be changed according to the specifications of each optical projection apparatus, the type of the light source, and the arrangement of the light sources. In this case, the fine pattern density distribution is shown in FIG. 9 b. As shown in), the reflective micro display 140 is disposed at a predetermined distance from the illumination plate 120 without being arranged to have a uniform distribution of luminance on the upper emission surface of the illumination plate 120. In view of the above, as shown in Fig. 9C, it is important to arrange the illuminance and the luminance distribution to be uniform.

Specifically, if the density distribution of the fine pattern is configured to have a uniform luminance distribution on the exit surface of the illumination plate 120, the uniform light distribution on the surface of the micro display that is one-to-one matching with the screen of the actual optical projection system. Not having it can lead to a reduction in the brightness uniformity of the projection system.

In other words, as shown in b) of FIG. 9, the fine pattern density distribution of the lighting plate 120 is not configured to have a uniform light distribution at the exit surface of the lighting plate 120, and the reflective micro-display 140 It is configured to have a uniform light distribution in the) plane.

9 a) shows the density distribution of the fine pattern in configuring the lighting plate 120 according to the embodiment of the present invention, where c) of FIG. 9 shows the luminance distribution of the upper portion of the lighting plate 120. The illuminance distribution of the light illuminated on the micro display 140 is shown.

That is, the light distribution is not uniform on the exit surface of the lighting plate 120 as shown in b) of FIG. 9, and is uniform on the reflective micro display 140 as shown in FIG. 9 c). By having a light distribution, the brightness uniformity of the optical projection apparatus is good, and the size of the entire projection apparatus can be miniaturized.

On the other hand, Figure 10 is a view showing a micro-projection apparatus according to a second embodiment of the present invention.

Referring to FIG. 10, the micro-projection apparatus 200 according to the second embodiment of the present invention includes an LED light source 210, an illumination plate 220, a polarizing beam splitter (PBS) 230, and silicon. And a liquid crystal display (LCOS) 240 and projection lenses 250a to 250d.

The microprojection apparatus 200 according to the second embodiment of the present invention uses the PBS 230 instead of the beam splitter 130 as compared to the microprojection apparatus 100 according to the first embodiment of the present invention described above. In addition, except that the LCOS 240 is used instead of the reflective micro display 140, the description of the same components will be omitted.

In the micro-projection apparatus 200 according to the second embodiment of the present invention, the PBS 230 divides the light emitted through the illumination plate 220 into a first polarization component and a second polarization component.

Here, the polarizing beam splitter (PBS) 230 is an optical element for dividing incident light into a first polarization component and a second polarization component, and the function of the PBS 230 is formed by the incident surface of light, that is, the incident beam, It is based on a vertical plane. The incident surface is also referred to as the reflective surface and is formed by the reflected light rays and is perpendicular to the reflective surface.

In the micro-projection apparatus 200 according to the second embodiment of the present invention, the LCOS 240 is disposed at a distance from the illumination plate, utilizes liquid crystal in a reflection mode, and divides the light through the polarizing beam splitter 230. The image is realized with the light.

The LCOS 240 refers to an integrated LCD on a silicon wafer, and the number of pixels is less than that of the LCD or DLP method described above, so that a high resolution panel can be manufactured at a low price.

In the micro-projection apparatus 200 according to the second embodiment of the present invention, the LED light source 210 is incident to the side of the lighting plate 220, the illumination plate by varying the shape and pattern density of the fine pattern Light emitted from the 220 may be uniformly illuminated on the silicon liquid crystal display (LCOS) 240.

In addition, in the micro-projection apparatus 200 according to the second embodiment of the present invention, as described above, the fine pattern of the lighting plate 220 is formed on the lower surface of the lighting plate 220, or the lighting plate It may be formed on the upper surface of the 220 or at the same time formed on the lower surface and the upper surface of the lighting plate 220.

11 is a diagram illustrating a micro-projection apparatus according to a third embodiment of the present invention.

Referring to FIG. 11, the micro-projection apparatus 300 according to the third embodiment of the present invention may include an LED light source 310, an illumination plate 320, a total internal reflection (TIR) prism 330, and a digital light source. And a micromirror device (DMD) 340 and projection lenses 350a to 350d.

Compared to the micro-projection apparatus 100 according to the first embodiment of the present invention described above, the micro-projection apparatus 300 according to the third embodiment of the present invention uses the TIR prism 330 instead of the beam splitter 130. Are substantially the same except for using the DMD 340 instead of the reflective micro display 140, and the description of the same components is omitted.

In the micro-projection apparatus 300 according to the third embodiment of the present invention, the TIR prism 330 has a surface that internally reflects light at some angle and passes light at another angle, and receives light provided from the lighting plate. It is separated from the image light reflected from the DMD.

In the micro-projection apparatus 300 according to the third embodiment of the present invention, the DMD 340 is disposed at a predetermined distance from the illumination plate 320, and the light separated by the total internal reflection (TIR) prism 330. To implement the image.

Here, the DMD 340 is a device for planting a 16 micron fine mirror on a silicon wafer at intervals of 1 micron and controlling the reflection of light through the mirror to express an image. The DMD 340 is a mirror device. Small microchips called mirror-devices play a key role. Hundreds of thousands of micro aluminum mirrors are placed on these microchips. These micromirrors switch the existing position to match the video signal. When the source emits light on the aluminum mirror surface, it is a basic principle of the DMD 340 that the mirror collecting the light through the lens scans the moving image.

In the micro-projection apparatus 300 according to the third embodiment of the present invention, the LED light source 310 is incident to the side of the lighting plate 320, the illumination plate by varying the shape and pattern density of the fine pattern Light emitted from 320 may be uniformly illuminated by the DMD 340.

In addition, in the micro-projection apparatus 300 according to the third embodiment of the present invention, as described above, the fine pattern of the illumination plate 320 is formed on the lower surface of the illumination plate 320, or the illumination plate It may be formed on the upper surface of the 320 or at the same time on the lower surface and the upper surface of the lighting plate 320.

12 is a diagram illustrating a micro-projection apparatus according to a fourth embodiment of the present invention.

12, the micro-projection apparatus 400 according to the fourth embodiment of the present invention includes an LED light source 410, an illumination plate 420, a wire grid polarizer (WGP) 460, and a polarization beam splitter (PBS). 430, a silicon liquid crystal display (LCOS) 440, and projection lenses 450a to 450d.

Compared to the micro-projection apparatus 200 according to the second embodiment of the present invention, the micro-projection apparatus 400 according to the fourth embodiment of the present invention, the wire grid polarizer (WGP: 460) is the illumination plate ( Except for being inserted between the 420 and the polarizing beam splitter (PBS) 430, the descriptions of the same elements are omitted.

That is, the WGP 460 is implemented in the form of a thin parallel conductor array and is inserted between the illumination plate 420 and the polarizing beam splitter (PBS) 430 to reflect light of orthogonal polarization while transmitting light of a specific polarization. Let's go.

Specifically, WGP 460 consists of a plurality of parallel conductive lines supported by a substrate. This WGP 460 is characterized by the pitch or period of the conductor, the width of the individual conductors, and the thickness of the conductors. For example, when a beam of light generated by the light source enters the polarizer at an angle θ from perpendicular to the plane of incidence perpendicular to the conductive element, the WGP 460 separates the beam into a specular reflection component and a diffractive transmission component.

In general, WGP 460 reflects light having an electric field vector parallel to the wires of the grid and transmits light having an electric field vector perpendicular to the wires of the grid. Ideally, WGP 460 functions as a complete mirror for one polarization of light, such as S polarization, and becomes completely transparent for other polarizations, such as P polarization. Such WGP 460 is useful in optical systems such as picture display systems and picture projection systems.

13 is a diagram illustrating a micro-projection apparatus according to a fifth embodiment of the present invention.

Referring to FIG. 13, the micro-projection apparatus 500 according to the fifth embodiment of the present invention includes an LED light source 510, an illumination plate 520, and a dual brightness enhancement film (DBEF) 560. And a polarizing beam splitter (PBS) 530, a silicon liquid crystal display (LCOS) 540, and projection lenses 550a to 550d.

Compared to the micro-projection apparatus 200 according to the second embodiment of the present invention, the micro-projection apparatus 500 according to the fifth embodiment of the present invention, the dual brightness enhancement film (DBEF) 560 is the illumination plate Except for being inserted between the 520 and the polarizing beam splitter (PBS) 530, the descriptions of the same elements are omitted.

That is, the DBEF 560 is a reflective polarizer, and is inserted between the illumination plate 520 and the polarizing beam splitter (PBS) 530 to improve the brightness of the light emitted from the illumination plate 520.

Specifically, the DBEF 560 is a dual brightness enhancement film manufactured by 3M, which refers to a reflective polarizer having a block direction leakage of 4 to 6 percent at normal incidence. The contrast ratio when using this DBEF 560 is limited to a maximum of 99: 1 or less for white light. However, DBEF 560 generates spectral leakage that reduces the contrast ratio of any color band as low as 25: 1, depending on the nature of the irradiated light source and the precise DBEF sample. In order to obtain good performance, good screen uniformity and lack of spectral leakage in the dark state will entail good average contrast of all relevant color bands.

The foregoing description of the present invention is intended for illustration, and it will be understood by those skilled in the art that the present invention may be easily modified in other specific forms without changing the technical spirit or essential features of the present invention. will be. It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive. For example, each component described as a single type may be implemented in a distributed manner, and similarly, components described as distributed may be implemented in a combined form.

The scope of the present invention is shown by the following claims rather than the above description, and all changes or modifications derived from the meaning and scope of the claims and their equivalents should be construed as being included in the scope of the present invention. do.

1 is a diagram illustrating a micro projection apparatus according to the prior art.

2 is a perspective view showing a micro projector according to the prior art.

3 is a diagram illustrating a schematic arrangement of an optical system viewed from the side of the micro-projector shown in FIG. 2.

4 is a diagram illustrating a micro-projection apparatus according to a first embodiment of the present invention.

5 is a block diagram of a micro-projection apparatus according to a first embodiment of the present invention.

FIG. 6 is a diagram illustrating an LED light source in the micro-projection apparatus shown in FIG. 3.

FIG. 7 is a diagram illustrating various lighting plates in the micro-projection apparatus shown in FIG. 3.

8A to 8C are diagrams illustrating the operating principle of the lighting plate according to the embodiment of the present invention, respectively.

9 is a diagram illustrating the illumination plate fine pattern density, the illumination plate brightness distribution and the brightness distribution illuminated on the display according to the embodiment of the present invention, respectively.

10 is a view showing a micro-projection apparatus according to a second embodiment of the present invention.

11 is a view showing a micro-projection apparatus according to a third embodiment of the present invention.

12 is a diagram illustrating a micro-projection apparatus according to a fourth embodiment of the present invention.

13 is a diagram illustrating a micro-projection apparatus according to a fifth embodiment of the present invention.

<Brief Description of Drawings>

100: first micro-projection device

110, 210, 310, 410, 510: light emitting diode (LED) light source

120, 220, 320, 420, 520: Illumination Plate

130: beam splitter

140: reflective micro display

150a ~ 150d, 250a ~ 250d, 350a ~ 350d, 450a ~ 450d, 550a ~ 550d: Projection Lens

200: second micro-projection device

230, 430, 530: Polarizing Beam Splitter (PBS)

240, 440, 540: Liquid Crystal On Silicon (LCOS)

300: third micro-projection device

330: Total Internal Reflection (TIR) prism

340: Digital Micro-mirror Device (DMD)

400: fourth micro-projection device

460: Wire Grid Polarizer (WGP)

500: fifth micro-projection device

560: Dual Brightness Enhancement Film (DBEF)

600: Screen / Wall

Claims (14)

delete delete delete delete In a micro-projection apparatus for projecting an image through a polarizing beam splitter, A light emitting diode (LED) or laser diode (LD) light source for emitting light separated by R, G, and B; An illumination plate having a plurality of fine patterns for reflecting the light incident from the light source upwardly without being emitted to the outside according to the total internal reflection condition; A polarizing beam splitter (PBS) for dividing the light emitted through the illumination plate into a first polarization component and a second polarization component; A liquid crystal display device (LCOS) disposed at a predetermined distance from the illumination plate, utilizing a liquid crystal in a reflection mode, and implementing an image with light split through the polarization beam splitter; And Projection lens to enlarge and project the light beam corresponding to the image implemented in the silicon liquid crystal display (LCOS) on the screen , &Lt; / RTI & And varying the shape and pattern density of the fine pattern so that the light emitted from the illumination plate is uniformly illuminated on the silicon liquid crystal display (LCOS). The method of claim 5, Implemented in the form of a thin parallel conductor array, and further includes a wire grid polarizer (WGP) inserted between the illumination plate and the polarizing beam splitter (PBS) for transmitting light of a specific polarization and reflecting light of orthogonal polarization. Micro projection device. The method of claim 5, A reflective polarizer, the micro-projection further comprising a Dual Brightness Enhancement Film (DBEF) inserted between the illumination plate and the polarizing beam splitter (PBS) to improve the brightness of light emitted from the illumination plate. Device. The method of claim 5, The micro-pattern of the lighting plate is formed on the lower surface of the lighting plate, the micro-projection apparatus, characterized in that formed on the upper surface of the lighting plate or formed simultaneously on the lower surface and the upper surface of the lighting plate. The method according to claim 5 or 8, The shape of the fine pattern is a micro-projection device, characterized in that selected from spherical, prismatic, pyramid, conical cylindrical and horizontal cylindrical. The method of claim 5, And a light distribution that is not uniform at the exit surface of the lighting plate, and is configured to have a uniform light distribution on the surface of the silicon liquid crystal display (LCOS). In a micro-projection apparatus for projecting an image through a digital micromirror element (DMD), A light emitting diode (LED) or laser diode (LD) light source for emitting light separated by R, G, and B; An illumination plate having a plurality of fine patterns for reflecting the light incident from the light source upwardly without being emitted to the outside according to the total internal reflection condition; A Total Internal Reflection (TIR) prism having a plane that internally reflects light at some angle and passes light at another angle, and separates the light provided from the illumination plate from the image light reflected from the DMD; A digital micro-mirror device (DMD) disposed at a predetermined distance from the illumination plate and configured to implement an image with light separated through the internal total reflection (TIR) prism; And Projection lens to enlarge and project the light beam corresponding to the image implemented in the digital micromirror element (DMD) on the screen , &Lt; / RTI & And the light emitted from the lighting plate is uniformly illuminated on the digital micromirror element by varying the shape and pattern density of the fine pattern. The method of claim 11, The micro-pattern of the lighting plate is formed on the lower surface of the lighting plate, the micro-projection apparatus, characterized in that formed on the upper surface of the lighting plate or formed simultaneously on the lower surface and the upper surface of the lighting plate. 13. The method according to claim 11 or 12, The shape of the fine pattern is a micro-projection device, characterized in that selected from spherical, prismatic, pyramid, conical cylindrical and horizontal cylindrical. The method of claim 11, The projection surface of the lighting plate is formed so that the light distribution is not uniform, and the micro-projection device, characterized in that configured to have a uniform light distribution on the surface of the digital micromirror element (DMD).

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