KR20100085363A

KR20100085363A - A projection device

Info

Publication number: KR20100085363A
Application number: KR1020090004602A
Authority: KR
Inventors: 박소연; 이상근
Original assignee: 엘지전자 주식회사
Priority date: 2009-01-20
Filing date: 2009-01-20
Publication date: 2010-07-29

Abstract

The present invention relates to a projection display device capable of efficiently reducing speckle using a wire grid PBS.

Description

Projection display device

The present invention relates to a display device, and more particularly, to a projection display device for projecting and displaying an image on a screen using light.

Recently, due to the rapid development of the display field, consumers want to see miniaturization and bright and clear images on a larger screen. As one of means for satisfying the needs of consumers, the development of a display device using laser light is actively progressing.

Using a laser as a light source has the advantage that the color of the image is clear, close to pure color, and has a wide range of color reproduction, and a high contrast allows a clear image to be obtained.

As described above, the laser display device of the prior art increases the sharpness of the color by using a laser, can display an image that is excellent in color reproducibility, close to the natural color, and can reproduce sharp image quality due to high contrast.

However, due to the coherence characteristic of the laser, the laser phenomenon occurs on the screen, resulting in a speckle phenomenon in which small grains are sparkling on the screen.

This speckle phenomenon reduces the contrast and resolution as a factor of degrading the image quality.

In order to eliminate the speckle phenomenon, an optical element such as a diffuser may be used, but the diffuser has a problem in that the transmittance of light is significantly reduced.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems of the prior art, and an object thereof is to provide a projection display device capable of efficiently reducing speckle using a wire grid PBS.

A projection display device according to a first embodiment of the present invention for achieving the above object comprises: an optical illumination system for generating and emitting light; An image projector for projecting an image onto a screen by irradiating laser light emitted from the optical illumination system; And a speckle reduction unit that separates the light projected by the image projector into P and S wave polarization components and reflects the separated P and S wave polarization components onto the screen to reduce speckle. .

In this case, the speckle reducing unit may be tilted to form an angle of 45 degrees with the optical path of the image projector, and may be formed of a wire grid PBS.

That is, the PBS is formed on the first surface to which the light of the image projector is incident, so that any one of the S-wave and P-wave polarization components of the incident light is reflected in the screen direction, and the remaining polarization components are A wide grid penetrating therein; And a reflector formed on a second surface of the image projector to emit light, and reflecting the polarization component passed into the screen toward the screen.

In this case, the reflector may be formed by reflecting a reflective mirror or the second surface.

In addition, the projection display device according to the second embodiment of the present invention, the optical illumination system for generating and emitting light; An image projector for projecting an image onto a screen by irradiating laser light emitted from the optical illumination system; And a speckle reduction unit that separates the light projected by the optical illumination system into P-wave and S-wave polarization components, and reflects the separated P-wave and S-wave polarization components to the display element to reduce speckle. .

Projection display device according to the present invention, by using a wire grid PBS to project the light projected on the screen by the S-wave and P-wave polarization components, thereby reducing the speckle due to the superimposed effect to provide a clear image quality have.

Other objects, features and advantages of the present invention will become apparent from the following detailed description of the embodiments.

A preferred embodiment of the projection display device according to the present invention will be described in detail with reference to the accompanying drawings.

Prior to describing the present invention, a projection display device according to the present invention includes a mobile phone, a smart phone, a notebook computer, a digital broadcasting terminal, a personal digital assistant (PDA), a portable multimedia player (PMP), The portable terminal may be manufactured and mounted in a module form in a portable terminal such as a navigation device and a non-portable terminal such as a desktop computer.

Hereinafter, the projection display device according to the present invention will be described in detail with reference to the drawings.

1 is a schematic structural diagram of a first embodiment showing a projection display device according to the present invention.

Referring to FIG. 1, the projection display apparatus 100 according to the first embodiment of the present invention includes an optical illumination system 110, an image projector 120, a power supply 130, and a speckle remover ( 140 and the controller 150.

Hereinafter, the projection display device 100 according to the first embodiment of the present invention may be configured to include other than the above-described components as necessary, but anything other than the above-described components is directly related to the present invention. Since it is not present, a detailed description thereof will be omitted below for simplicity of explanation.

On the other hand, it should be noted that the components may be configured by combining two or more components into one component, or one component may be subdivided into two or more components as necessary when implemented in actual applications.

Hereinafter, components of the projection display apparatus 100 according to the first embodiment of the present invention will be described.

First, the illumination optical system 110 according to the present invention will be described in detail with reference to FIG. 2.

2 is a view showing an illumination optical system according to the present invention.

Referring to FIG. 2, the illumination optical system 110 includes a light source unit 111 and a color combining unit 112.

The light source unit 111 is composed of red (R), green (G), and blue (B) laser diodes 111a, 111b, and 111c, and a laser generated from the laser diodes 111a, 111b, and 111c. Exit the light.

The color combining unit 112 may be configured with a plurality of dichroic mirrors 112a and 112b and may be configured with a plurality of dichroic mirrors 112a and 112b.

That is, the first and second dichroic mirrors 112a and 112b are mirror-type compounding parts capable of selectively reflecting or transmitting only light having a specific wavelength to obtain light of a desired wavelength band, and the light source parts 111a and 111b. , 111c) transmits or reflects a portion of the light generated.

In this case, the first dichroic mirror 112a may be provided at a point where the red laser light and the green laser light cross each other. That is, the first dichroic mirror 112a transmits the red laser light and reflects the green laser light to emit the light.

In addition, the second dichroic mirror 112b transmits the red laser light and the green laser light passing through the first dichroic mirror 112a, and reflects the blue laser light and emits the light.

As such, the red laser light, the green laser light, and the blue laser light are synthesized while passing through the two dichroic mirrors 112a and 112b and synthesized into laser light of various colors according to an image to be formed.

The present invention has been described under the assumption that the first dichroic mirror 112a is provided at the point where the red laser light and the green laser light intersect, and the positions of the dichroic mirrors 112a and 112b according to the present invention are described. It is not limited to this.

In addition, although not shown in FIG. 2, a collimating lens for converting the laser light into parallel light may be further provided between the laser light source 110 and the dichroic mirrors 120a, 120b, and 120c.

In addition, although not shown in FIG. 2, an optical tunnel may be further provided between the dichroic mirrors 120a, 120b, and 120c and the speckle reduction unit 130.

The optical tunnel may be composed of a rod lens made of a glass glass material, and the rod lens has a high refractive index characteristic having a higher refractive index than air, and thus total internal reflection occurs.

In addition, the optical tunnel may be formed as a light tunnel (Tunnel) of the type surrounded by a mirror (Mirror) open the entrance / exit port, for example, is configured to form a tunnel surrounded by four mirror surfaces.

Meanwhile, the power supply unit 130 supplies power required for driving the projection display apparatus 100 according to the present invention to each component under the control of the controller 150, and the controller 150 according to the present invention. The operation of the projection display apparatus 100 is controlled.

Hereinafter, the speckle reduction unit 140 according to the present invention will be described in detail with reference to FIG. 3.

3 is a diagram illustrating a first embodiment of a speckle reducing unit according to the present invention.

Referring to FIG. 3, the speckle reduction unit 140 according to the first embodiment of the present invention is disposed between the optical illumination system 110 and the image projector 120.

The speckle reduction unit 140 splits the light transmitted from the optical illumination system 110 into P-wave and S-wave polarization components, and emits the separated P-wave and S-wave polarization components to the image projector 120. .

In this case, the speckle reduction unit 140 is tilted to form an angle of 45 degrees with the optical path of the optical illumination system 110.

In addition, the speckle reduction unit 140 is formed using a wire grid PBS.

That is, the speckle reduction unit 140 is a reflection formed on the wire grid 141 formed on the first surface on which the light of the optical illumination system 110 is incident and on the second surface on which the light of the optical illumination system 110 is emitted. It is configured to include a portion 142.

The wire grid 141 reflects one of the S- and P-wave polarization components of the light incident from the optical illumination system 110 toward the image projector 120, and transmits the remaining polarization components therein. .

That is, referring to FIG. 3, the wire grid 141 reflects the S-wave polarization component of the light incident from the optical illumination system 110 to the image projector 120 and transmits the remaining P-wave component to the inside. It is showing.

In addition, the reflector 142 reflects the P-wave polarization component transmitted through the wire grid 141 to the image projector 120.

In this case, the reflector 142 may be formed by attaching a reflection mirror to the inside or the outside of the second surface, and may also be formed by the reflective coating on the inside or the outside of the second surface.

As described above, the S-wave and P-wave polarization components are separated from the single light by the speckle reduction unit 140 according to the present invention, and the S-wave and P-wave components separated by the speckle reduction unit 140. Is projected onto the screen through the image projector 120, and the S-wave and P-wave components projected on the screen form different interference fringes.

As described above, since speckle patterns generated by continuous interference fringe change are shown as the average of the speckle patterns when viewed on the screen, the speckle that is displayed on the screen when the user views an image through the screen. This appears to be reduced.

Hereinafter, the image projector 120 according to the present invention will be described in detail with reference to FIGS. 4 to 7.

4 is a configuration diagram of an embodiment of a display panel image projector according to the present invention.

Referring to FIG. 4, the image projector 120 of the display panel type includes a reflector 121, a display panel 122, and a projection lens 123.

The display panel 122 receives the laser light corresponding to the S-wave and P-wave polarization components separated from the speckle reduction unit 140 through the reflector plate 121, and displays an image on the screen using the incident laser light. To project.

The display panel 122 as described above is a digital micro mirror device for forming an image by selectively reflecting the incident laser light on a pixel-by-pixel basis, and a liquid crystal display device (Liquid Crystal on Silicon; It may be formed by a reflective image forming unit or the like.

The projection lens 123 enlarges and projects the image formed on the display panel 122 on the screen.

In addition, the image projector 120 according to the present invention may be formed as a scanner-type image projector 120, as shown in Figure 4 to 7 below.

5 is a configuration diagram of an embodiment of a scanner projecting image projector according to the present invention.

Referring to FIG. 5, laser light corresponding to the S-wave and P-wave polarization components separated by the speckle reduction unit 140 is incident through the reflector 121 to the scanner 124.

The scanner 124 reflects the laser light incident through the reflector 121 in a horizontal and / or vertical direction to perform raster scan on a screen.

The scanner 124 has at least one micro scanner with a rotatable mirror. An example of such a micro scanner is a biaxial drive micro scanner shown in FIGS. 6 and 7.

Hereinafter, the micro scanner 124 according to the present invention will be described in detail with reference to FIGS. 6 and 7.

Figure 6 is a perspective view of an embodiment of a micro scanner according to the present invention.

FIG. 7 is a schematic conceptual view illustrating a state in which a connection portion is formed in the micro scanner of FIG. 6.

As shown in FIGS. 6 and 7, the micro scanner 124 includes a mirror plate 51 including a thin film on which a reflective surface for reflecting laser light is formed, and a support frame positioned below the thin film to support the thin film. And an outer frame 52 spaced apart from the outside of the mirror plate 51, a plurality of connecting portions 53A, 53B, 54 connecting the mirror plate 51 and the outer frame 52, and A gimbal 56 spaced apart from the outside of the outer frame 52 and connected to the gimbal 56 and the outer frame 52 and symmetrically formed with respect to the mirror plate 51. It is formed symmetrically with respect to the pair of inner elastic flexural structure 57 and the mirror plate 51, and is connected to the gimbal 56 and the pair of supports 75 and the mirror plate 51 A pair of outer elastic flexures that lift the outer frame 52 and gimbal 56 from the bottom. Structure 58.

Here, the plurality of connecting portions 53A, 53B, and 54 connecting the mirror plate 51 and the outer frame 52 are connected to the pair of elastic bending structures 58 as illustrated in FIG. 6. A second connection portion formed on one line P1 and symmetrically formed with respect to the mirror plate 51, and a second line P2 perpendicular to the first line P1 and formed on the mirror plate 51. The first connector 54 is formed symmetrically with respect to 51.

The gimbal 56 is connected to the outer frame 52 by the inner elastic bending structure 57, the outer elastic bending structure is formed symmetrically on a line perpendicular to the inner elastic bending structure (57). It is connected with the support part 75 by the 58.

The outer elastic flexural structure 58 connects the gimbal 56 with the support 75 to lift the mirror plate 51, the outer frame 52 and the gimbal 56 from below. Here, only a part of the support 75 is schematically shown.

The inner elastic flexural structure 57 and the outer elastic flexural structure 58 provide a restoring force torque when the micromirror is driven and act as a rotation axis.

That is, the outer frame 52 rotates the inner elastic flexural structure 57 as an axis (axis connecting X and X ′, hereinafter referred to as X axis) as shown in FIG. 6, and the gimbal 56 Rotates the outer elastic flexural structure 58 as an axis (axis connecting Y and Y ', hereinafter referred to as Y axis) as shown in FIG. 6.

In the case of the micro scanner 124 having such a structure, it is possible to rotate in two axes of freedom. That is, the rotational movement in the X-axis direction with respect to the X-axis with respect to the inner elastic flexural structure 57 and the outer elastic flexural structure 58 is possible, the movement in each axial direction is gimbal 56 Since the structure does not affect each other and can be controlled independently, it is possible to implement a micro mirror having an arbitrary angle in a two-dimensional plane.

By using the micro scanner 124 as described above, scanning is performed by the micro-rotation of the mirror plate 51, so that it is possible to sweep at a very high speed.

By such a rapid sweep, the projection display device according to the present embodiment can increase the contrast ratio compared to the conventional display device.

Second Embodiment

8 is a schematic structural diagram of a second embodiment showing a projection display device according to the present invention.

9 is a view showing a second embodiment showing a speckle reducing unit according to the present invention.

8 and 9, the speckle reduction unit 140 according to the present invention is disposed between the image projector 120 and the screen.

That is, the speckle reduction unit 140 splits the light projected by the image projector 120 into P wave and S wave polarization components and projects the separated P wave and S wave polarization components onto the screen.

In this case, the speckle reduction unit 140 is tilted to form an angle of 45 degrees with the optical path of the image projector 120.

In addition, the speckle reduction unit 140 is formed using a wire grid PBS.

That is, the speckle reduction unit 140 may be formed on the wire grid 141 formed on the first surface on which the light of the image projector 120 is incident and on the second surface on which the light of the image projector 120 is emitted. It is configured to include a reflecting portion 142 formed.

The wire grid 141 reflects one of the S and P wave polarization components of the light incident from the image projector 120 in the screen direction, and transmits the remaining polarization components therein.

That is, referring to FIG. 9, the wire grid 141 reflects the S-wave polarization component of the light incident from the image projector 120 to the screen and transmits the remaining P-wave component to the inside. .

In addition, the reflector 142 reflects the P-wave polarization component transmitted therein by the wire grid 141 to the screen.

As described above, the S-wave and P-wave polarization components are separated from the single light by the speckle reduction unit 140 according to the present invention, and the S-wave and P-wave components separated by the speckle reduction unit 140. Is projected on the screen, and the S- and P-wave components projected on the screen form different interference patterns.

It will be apparent to those skilled in the art that the present invention can be embodied in other specific forms without departing from the spirit and essential features of the present invention.

Accordingly, the above detailed description should not be construed as limiting in all aspects and should be considered as illustrative.

The scope of the invention should be determined by reasonable interpretation of the appended claims, and all changes within the equivalent scope of the invention are included in the scope of the invention.

Claims

An optical illumination system for generating and emitting light;

An image projector for projecting an image onto a screen by irradiating laser light emitted from the optical illumination system; And

And a speckle reduction unit that separates the light projected by the image projector into P-wave and S-wave polarization components, and reflects the separated P-wave and S-wave polarization components onto the screen to reduce speckle. Projection display device.

According to claim 1,

The speckle reducing unit is tilted to form an angle of 45 degrees with an optical path of the image projector.

According to claim 1,

The speckle reduction unit is a wire grid PBS.

The method of claim 3, wherein the PBS,

A wide grid which is formed on a first surface to which light of the image projector is incident, reflects one of the polarization components of the S-wave and P-wave polarization components of the incident light in the screen direction, and transmits the remaining polarization components to the inside; ; And

And a reflector formed on a second surface of the image projector, through which light is emitted, to reflect the polarization component passing through the light toward the screen.

5. The method of claim 4,

And the reflector is formed by reflecting a reflective mirror or the second surface.

An optical illumination system for generating and emitting light;

And a speckle reduction unit that separates the light projected by the optical illumination system into P-wave and S-wave polarization components, and reflects the separated P-wave and S-wave polarization components to the image projector to reduce speckle. Projection display device.

The method according to claim 6,

The speckle reducing unit is tilted to form an angle of 45 degrees with the optical path of the optical illumination system.

The method according to claim 6,

The speckle reduction unit is a wire grid PBS.

The method of claim 8, wherein the PBS,

The light of the optical illumination system is formed on the first surface incident, the polarization component of any one of the S-wave and P-wave polarization components of the incident light is reflected in the direction of the image projector, and the remaining polarization components are transmitted therein Wide grid; And

And a reflector formed on a second surface from which the light of the optical illumination system is emitted and reflecting the polarization component passed therein toward the image projector.

The method of claim 9,