KR100421860B1 - projection-type video display appliance with reflection-type LCD - Google Patents

Abstract

The present invention relates to a projection type image display apparatus using a reflective liquid crystal panel, and to uniformly polarize the light incident on the reflective liquid crystal panel, and to prevent foreign substances from adhering to the surface of the liquid crystal panel to form a liquid crystal panel. This is to improve the image quality of the image.

To this end, the present invention comprises a condenser lens (33), (35), (37) for condensing light emitted from the light source (1); Polarizing beam splitters 43, 45, and 47 for reflecting and separating a specific wave of light incident through the condenser lenses 33, 35, and 37 by 90 °; ; Reflective liquid crystal reflecting to the polarizing beam splitter 43, 45, 47 after forming the image by receiving a specific wave of light reflected from the polarizing beam splitter 43, 45, 47 Panels 53, 55, and 57; The polarization beam splitter 43, 45, 47 is provided between the liquid crystal panel 53, 55, 57, the polarization beam splitter 43, 45, 47 A projection type image display apparatus using a reflective liquid crystal panel including a wave plate 90 for controlling the polarization state of light incident on the liquid crystal panels 53, 55, and 57 reflected by is provided.

Description

Projection-type video display appliance with reflection-type LCD}

The present invention relates to a projection image display device, and more particularly, to a projection image display device using a reflective liquid crystal panel for forming and reflecting an image.

In general, a projection image display device is a device that enlarges and projects an image formed on a liquid crystal panel by using a projection optical system using a liquid crystal panel as an optical switch element. A representative example of such a projection image display device is a liquid crystal projector.

On the other hand, the liquid crystal projector described above has a single plate type using one liquid crystal panel equipped with three color filters of red (R), green (G), and blue (B), and a monolithic liquid crystal panel for each of R, G, and B optical paths. The three-plate type liquid crystal projector is divided into three-plate type using three liquid crystal panels, and there are a projector using a transmissive liquid crystal panel and a projector using a reflective liquid crystal panel.

1 is a configuration diagram of an optical system of a general reflective liquid crystal projector. In the reflective liquid crystal projector configured as shown, white light is irradiated from the light source 101, and the dichroic mirror 105 and the reflector 120 are white light. The spectroscopy is performed with red (R), green (G), and blue (B), and the light of each spectroscopic color is guided into three separate optical paths.

As described above, each of the colors induced by the three light paths is reflected by the S-wave polarized by the polarization beam splitter 140 and is incident on the reflective liquid crystal panel 150 corresponding to each color to form an image.

Then, the light incident on each of the reflective liquid crystal panels 150 passes through the polarization beam splitter 140 to be condensed by the dichroic prism 108, and is projected on the screen through the projection lens 109. will be.

On the other hand, the optical system of the above-described reflective liquid crystal projector is only an example, and various types of reflective liquid crystal projectors have been developed for obtaining images having high light efficiency, high quality, and high brightness.

According to the present invention, in a projection type image display device using a reflective liquid crystal panel, the polarization state of light incident on the liquid crystal panel is uniform, and the image quality of the image formed by the liquid crystal panel is prevented by preventing foreign matter from adhering to the surface of the liquid crystal panel. It is to improve.

1 is a configuration diagram showing an example of an optical system of a conventional reflective liquid crystal projector

2 is a configuration diagram showing an optical system of a projection image display device using a reflective liquid crystal panel to which the present invention is applied.

3 is an enlarged view of a portion A of FIG. 2;

4 is an exploded perspective view of a liquid crystal panel assembly and an aligner assembly of a projection image display device using a reflective liquid crystal panel to which the present invention is applied;

5 is a block diagram showing an optical system of a projection image display device using a reflective liquid crystal panel according to the present invention;

FIG. 6 is an enlarged view of portion A ′ of FIG. 5;

7 is an exploded perspective view of a liquid crystal panel assembly and an aligner assembly of a transmissive image display apparatus using a reflective liquid crystal panel according to the present invention;

** Description of symbols for the main parts of the drawing **

1. Light source 2. UV / IR filter

3. fly eye lens 4. flat plate polarized beam separator

5. Dichroic mirror 6. λ / 2 wave plate

7. λ / 4 wave plate 8.Dichroic prism

9. Projection Lens 21,22,23. Reflector

31-37. Condenser lens 43,46,47. Polarized beam separator

53,56,57. Reflective liquid crystal panel 60. Liquid crystal panel assembly

61. Fastening member 70. Align assembly

80. Foreign material blocking plate 90. Wavelength plate

91. Wave plate holder 92. Groove

In order to achieve the above object, the present invention includes a condenser lens for condensing light emitted from a light source; A polarizing beam splitter for reflecting and separating a specific wave of light incident through the condenser lens at 90 °; A reflection type liquid crystal panel that receives a specific wave of light reflected from the polarization beam splitter and forms an image and then reflects the polarization beam splitter; Provided between the polarizing beam splitter and the liquid crystal panel, there is provided a projection type image display device using a reflective liquid crystal panel comprising a wave plate which is reflected from the polarizing beam splitter to adjust the polarization state of the light incident on the liquid crystal panel do.

With reference to the preferred embodiments of the present invention 2 to 7 will be described in more detail.

2 is a block diagram showing an optical system of a transmissive image display apparatus using a reflective liquid crystal panel to which the present invention is applied.

As shown, a transmissive image display apparatus using a reflective liquid crystal panel to which the present invention is applied includes a light source 1 for irradiating light, an ultraviolet-infrared ray filter (UV-IR filter) 2 for transmitting only visible light, A fly ice lens 3 for improving the distribution of light, a flat polarizing beam splitter 4 for polarizing non-polarized light, and first to second light directions Three reflectors 21, 22, 23, a dichroic mirror 5 for reflecting light of a specific color, and first to seventh condensing lenses 31 to 37 for condensing light; Polarized beam splitters 43, 45, and 47 for reflecting and separating a specific wave of light of each color (blue, green, red), and liquid crystal panels 53, 55, and 57 for forming and reflecting an image; A λ / 2 wave plate 6 and a λ / 4 wave plate 7 for converting the polarization state of the light, a dichroic prism 8 for combining the light, and the synthesized light It consists of a projection projecting lens 9 to.

In particular, the transmissive image display apparatus using the reflective liquid crystal panel to which the present invention is applied has a condensing lens 33 for condensing light for each color (green, blue, red) as shown by the dotted line A shown in FIG. 35, 37, polarized beam splitters 43, 45, 47 for passing P waves and reflecting S waves in the light of each color passing through the condenser lenses 33, 35, 37, and the polarized beams It has a common configuration consisting of reflective liquid crystal panels 53, 55 and 57 which receive S waves reflected by the separators 43, 45 and 47 to form an image and reflect it again.

Specifically, 43 is a green polarization beam splitter, 53 is a green liquid crystal panel, 45 is a blue polarization beam splitter, 55 is a blue liquid crystal panel, 47 is a red polarization beam splitter, and 57 is a red liquid crystal panel. Indicates.

Meanwhile, a separate polarization beam splitter 49 is provided between the green polarization beam splitter 43 and the blue polarization beam splitter 45.

The operation of the transmissive image display device using the reflective liquid crystal panel to which the present invention is configured as described above will be described as follows.

The light irradiated from the light source 1 passes through only the visible light (380 nm to 780 nm) by the UV / IR blocking filter 2, and the visible light passing through the filter 2 is evenly distributed by the fly's eye lens 3. Non-polarized visible light is polarized with S-waves in the planar polarization beam splitter 4, is collected by the first condenser lens 31, and the direction of light is switched in the first reflector 21.

The light reflected by the first reflector 21 is collected by the second condenser lens 32 and then incident on the dichroic mirror 5, wherein the light of blue (B) and green (G) is It is transmitted and the red (R) light is reflected.

Then, the light of blue (B) and green (G) passing through the dichroic mirror (5) is condensed by the third condenser lens 33, and then the green polarization beam splitter having a color separation function ( 43) blue (B) light is transmitted, and S-green light is reflected from the oblique plane of the green polarization beam splitter 43.

The blue (B) light that has passed through the green polarization beam splitter 43 is collected by the fourth condenser lens 34 and polarized with P waves while passing through the λ / 2 wave plate 6, and a separate polarization beam. After passing through the separator 49, the direction of the light in the second reflector 22 is switched.

Subsequently, the blue (B) light of the P wave reflected by the second reflector 22 passes through the λ / 4 wave plate 7 and the sixth condenser lens 36 and is reflected by the third reflector 23. And polarized with S waves while passing through the [lambda] / 4 wave plate 7 again.

The light polarized by the S wave as described above is reflected from the oblique plane of the polarization beam splitter 49 and passes through the fifth condenser lens 35, and then is incident to the blue polarization beam splitter 45. Light does not pass through the blue polarization beam splitter 55 as it is S-beam, but is reflected at the oblique plane.

The reflected S-waves are incident on the blue reflective liquid crystal panel 55, are controlled by an image signal applied to the liquid crystal panel 55, and are polarized into P waves, and the blue polarization beam splitter 45 is used. To be reflected back.

Meanwhile, the S wave of the green (G) light reflected by the green polarization beam splitter 43 is incident on the green reflective liquid crystal panel 53 and is controlled by an image signal applied to the liquid crystal panel 53. Polarized by P-wave, reflected back to the green polarization beam splitter 43.

In addition, the red (R) light reflected by the dichroic mirror (5) passes through the seventh polarization lens (37), wherein the red (R) light is S-wave polarized beam splitter ( 47 is reflected from the oblique plane and is incident on the red reflective liquid crystal panel 57, controlled by an image signal applied to the liquid crystal panel 57, and polarized by P waves, and reflected back to the polarization beam splitter 47. .

As described above, the light of blue (B), green (G), and red (R) having passed through the polarization beam splitters 43, 45, and 47 of each color is synthesized by the dichroic prism 8 to produce a projection lens ( 9) is projected onto the screen.

FIG. 3 is a state diagram illustrating that light of each color is incident and reflected on each polarizing beam splitter of a transmissive image display device using a reflective liquid crystal panel to which the present invention is applied. FIG. .

As shown, each of the polarizing beam splitters 43, 45, 47 has a diagonal reflective oblique plane of 45 °, and on one side of the polarizing beam splitter 43, 45, 47 (rear side of the traveling direction of the light), 33, 35, and 37 are respectively provided, and on the other side, the reflective liquid crystal panels 53, 55, and 57 are formed at an angle of 90 ° with the condensing lenses 33, 35, and 37.

However, since most of the light passing through the central portion of the condenser lenses 33, 35 and 37 is parallel light, the parallel light forms an inclination angle of 45 ° with the reflected oblique plane of the polarization beam splitters 43, 45 and 47. You will join.

Accordingly, only S-waves of the parallel light are reflected by the reflective oblique planes of the polarization beam splitters 43, 45, and 47 to the liquid crystal panels 53, 55, and 57, and thus the polarization of the liquid crystal panels 53, 55, and 57 is reflected. The state is uniform.

However, since the light passing through the periphery of the condenser lenses 33, 35, 37 is non-parallel light, the non-parallel light has an inclination angle of 45 ° or more or less with the reflected oblique plane of the polarization beam splitters 43, 45, 47. In this case, not only the S-waves of the non-parallel light but also some P-waves having noise components are reflected to the liquid crystal panels 53, 55, and 57.

As a result, the polarization states of the edges of the liquid crystal panels 53, 55, and 57 are nonuniform according to the positions of the liquid crystal panels 53, 55, and 57. Since the image signal is not properly transmitted, the image quality of the projected image eventually causes a difference in contrast and color according to the screen position, and also reduces the light efficiency.

4 is an exploded perspective view of the liquid crystal panel assembly and the aligner assembly of the transmissive image display apparatus using the reflective liquid crystal panel to which the present invention is applied.

As shown in the figure, the liquid crystal panel assembly 60 includes reflective liquid crystal panels 53, 55 and 57, and a fixing member 61 having grooves in which the reflective liquid crystal panels 53, 55 and 57 are seated at a central portion thereof. Is made of a combination of

In addition, the alignment assembly 70 is configured to move the liquid crystal panel assembly 60 in up, down, left and right directions, and to adjust the position of the image by the liquid crystal panels 53, 55 and 57.

In addition, a foreign matter blocking plate 80 is provided between the liquid crystal panel assembly 60 and the alignment assembly 70 to prevent foreign matter from adhering to the surfaces of the liquid crystal panels 53, 55, and 57.

On the other hand, both the alignment assembly 70 and the central portion of the foreign matter blocking plate 80 is opened to allow light to pass through.

However, the foreign matter blocking plate 80 may block foreign matter from entering the liquid crystal panels 53, 55, and 57 in a direction in which light travels, that is, in a direction perpendicular to the liquid crystal panels 53, 55 and 57. Foreign substances such as dust introduced into the vertical gap formed by the liquid crystal panel assembly 60 and the foreign matter blocking plate 80 may not be blocked.

Therefore, the foreign matter is introduced through the coupling gap between the liquid crystal panel assembly 60 and the foreign material blocking plate 80 is attached to the surface of the liquid crystal panel (53, 55, 57) to form the liquid crystal panel (53, 55, 57) This will adversely affect the image quality of the image.

As described above, the present invention is to obtain a clear image quality by making the polarization state of the liquid crystal panel uniform and preventing foreign matter from adhering to the surface of the liquid crystal panel.

5 is a block diagram illustrating an optical system of a transmissive image display device using a reflective liquid crystal panel according to the present invention, FIG. 6 is an enlarged view of a portion A 'of FIG. 5, and FIG. 7 is a reflective liquid crystal panel according to the present invention. It is an exploded perspective view of the liquid crystal panel assembly and aligner assembly of the transmissive image display apparatus used.

As shown in the figure, in order to obtain a clear image quality by correcting the image quality difference of the image formed by the reflective liquid crystal panels 53, 55 and 57, each color incident through each condenser lens 33, 35, 37 Each polarized beam splitter (43, 45, 47) for reflecting and separating a specific wave of light of the light receiving the specific wave of light separated by each of the polarized beam splitter (43, 45, 47) to form an image A wave plate 90 is provided between each of the liquid crystal panels 53, 55, and 57 that are reflected by the polarization beam splitters 43, 45, and 47. The principle of changing the polarization state of light according to the angle of the wave plate is used. will be.

On the other hand, since the configuration and operation of the overall optical system of the projection image display device using the reflective liquid crystal panel to which the present invention is applied as described above, the same configuration will be given the same reference number for a detailed description thereof.

In detail, the wavelength plate 90 uses a λ / 4 wave plate, and the liquid crystal panel assembly 60, the foreign material blocking plate 80, the wave plate 90, and the alignment assembly ( 70) are combined sequentially.

Here, the λ / 4 wave plate 90 emits light incident to the linearly polarized light in accordance with the polarization axis to the left circularly polarized light or right circularly polarized light, or the light incident to the left circularly polarized light or the right circularly polarized light is linearly polarized light. It has an optical characteristic to be emitted.

On the other hand, if the λ / 4 wave plate 90 and the linearly polarized light incident on the axis does not match, the light efficiency and contrast is reduced by a non-matching angle, for this purpose, the λ / 4 wave plate 90 Rotating means for rotating is provided.

Rotating means for this is provided with a wave plate holder 91 so that the λ / 4 wave plate 90 is fitted on the circumference of the λ / 4 wave plate 90, and around the wave plate holder 91 The recess 92 is formed to rotate the λ / 4 wave plate 90.

Accordingly, by rotating the wave plate holder 91 in accordance with the polarization state of the light incident on the [lambda] / 4 wave plate 90, the axis of the [lambda] / 4 wave plate 90 can be freely adjusted to contrast the image. It can optimize the contrast, light efficiency.

Specifically, the light passing through the periphery of the condenser lens 33, 35, 37 is incident to the reflective oblique surface of the polarization beam splitter 43, 45, 47 at an angle of inclination of 45 ° or more or less, wherein the polarization As described above, not only the S-wave but also some P-waves having noise components are reflected on the liquid crystal panels 53, 55, and 57 on the reflective oblique surfaces of the beam splitters 43, 45, and 47.

In this case, according to the present invention, the λ / 4 wave plate 90 is provided between the polarization beam splitters 43, 45, 47 and the liquid crystal panels 53, 55, 57. By adjusting the angle of the light, the light incident on the liquid crystal panels 53, 55, and 57 can have a uniform polarization state, thereby improving the image quality of the image formed by the liquid crystal panels 53, 55, and 57. Can be.

Meanwhile, upper and lower protrusions 81 and lower protrusions 82 protruding toward the liquid crystal panel assembly 60 are formed at upper and lower ends of the foreign matter blocking plate 80 coupled to one surface of the liquid crystal panel assembly 60. The foreign material blocking plate 80 is formed in a λ shape.

In this case, the upper protrusion 81 and the lower protrusion 82 of the foreign matter blocking plate are formed so that a gap does not occur between them when the liquid crystal panel assembly 60 and the foreign matter blocking plate 80 are coupled to each other. In order to prevent foreign substances from flowing in from the upper and lower directions of the liquid crystal panels 53, 55 and 57.

As a result, in the present invention, foreign matters may be prevented from adhering to the surfaces of the liquid crystal panels 53, 55, and 57 by the foreign matter blocking plate 80 formed in a λ shape.

The present invention described above is provided with a wave plate between the polarizing beam splitter and the liquid crystal panel to make the polarization state of the light incident on the liquid crystal panel uniform, and the foreign material blocking plate is formed in the? In addition, it is possible to block foreign substances flowing in from the up and down direction of the liquid crystal panel, thereby improving the image quality of the image formed by the liquid crystal panel.

Claims (6)

A condenser lens for condensing light emitted from the light source; A polarizing beam splitter for reflecting and separating a specific wave of light incident through the condenser lens at 90 °; A reflection type liquid crystal panel that receives a specific wave of light reflected from the polarization beam splitter and forms an image and then reflects the polarization beam splitter; A wavelength plate provided between the polarization beam separator and the liquid crystal panel, the wavelength plate adjusting the polarization state of light reflected from the polarization beam separator and incident on the liquid crystal panel, and rotating means for rotating the wavelength plate, The rotating means is a projection image display device using a reflective liquid crystal panel, characterized in that the groove is formed around the wave plate holder in which the center portion is opened so that the wave plate is fitted. delete delete The method of claim 1, The wavelength plate is a projection type image display device using a reflective liquid crystal panel, characterized in that the lambda / 4 wavelength plate. The method of claim 1, A projection image display device using a reflective liquid crystal panel, characterized in that a foreign matter blocking plate is provided around the liquid crystal panel to prevent foreign matter from adhering to the surface of the liquid crystal panel. The method of claim 5, wherein Projection type image display device using a reflective liquid crystal panel, characterized in that the projection formed on the upper and lower ends of the foreign material blocking plate is formed in a λ shape.