KR20020090387A - Color Scrolling Apparatus of Projector using Display Device Projector of Single Panel Type - Google Patents

Abstract

PURPOSE: A color scrolling apparatus is provided to achieve improved optical efficiency, while reducing manufacturing cost and obtaining uniform optical distribution. CONSTITUTION: A color scrolling apparatus comprises a light source for generating light; a light dividing optical system for dividing the light from the light source into red, green and blue lights; drums(50A,50B) disposed at the optical paths of red, green and blue lights, which rotate to block or permit red, green and blue lights to pass, to thereby scroll red, green and blue lights; a photo synthesis optical system for synthesizing the scrolled red, green and blue lights; and a mirror(50C) for changing advancing direction of light. Each of first to third drums, includes a barrier disposed at the optical path, which cuts off the incident light; and an aperture for passing the light.

Description

Color Scrolling Apparatus of Projector using Display Device Projector of Single Panel Type}

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a single-panel display device that enlarges and projects a small image implemented on one display device onto a screen. In particular, the present invention relates to a color scrolling device of a single-panel display device that has a uniform light distribution while improving light efficiency. It is about.

The projector displays an image of the large screen by enlarging and projecting a digestive image implemented in an internal small display onto a large screen using a projection lens. This projector is divided into a front projection method in which an image is projected on the front of the screen and a rear projection method in which an image is projected on the rear of the screen. Among these, a projection television is mentioned as a typical example of the latter. In addition, a cathode ray tube (CRT) and a liquid crystal display (hereinafter referred to as "LCD") are used as a display for providing a small image from a projector. Recently, there is a growing interest in projectors using LCDs, which are advantageous for thinning projectors.

A display device typically includes an LCD for providing a fire extinguishing image, a projection lens system for expanding and projecting a fire extinguishing image displayed on the LCD, a light source for providing light to the LCD, and an illumination system for adjusting an optical path between the light source and the LCD And a driving circuit section for signal processing.

Such display devices tend to implement high brightness through an efficient optical system configuration and lamp change, and a trend of emphasizing the ease of portability and installation through miniaturization and light weight even though the brightness is somewhat reduced.

A projector using such a display element uses three or one display element for color implementation. Three display elements are employed for the purpose of high brightness, but one display element is generally employed for the purpose of miniaturization and light weight.

In order to implement a color, a single-plate projector employing a single display element uses a method of using a color filter, a method of separating three primary colors and entering them at a specific angle, and a method of sequentially sending three primary colors to the display element. Among them, a method of using a rotating prism as shown in FIG. 1 is typical of an image projecting device that sequentially sends three primary colors to a display device.

Referring to FIG. 1, an optical system of a single plate display device including a conventional color scrolling device is schematically illustrated.

The display element shown in FIG. 1 includes first and second fly eye lenses disposed on an optical path between a light source 2 for generating light and an optical path between the light source 2 and the condenser lens 8. "FEL" (4, 6), a polarizing beam splitter array (hereinafter referred to as "PBS array") (7), and the first to fourth transmission and reflection of light of a specific wavelength band Dichroic mirrors 10, 12, 24, 26, first to third rotating prisms 16, 18, and 20 that change optical paths according to rotation angles, and second dichroic mirrors 10 and A first total reflection mirror 14 positioned between the third scrolling device, a second total reflection mirror 22 positioned between the first scrolling device 16 and the third dichroic mirror 24, and a display element ( 30 and a polarizing beam splitter (hereinafter referred to as "PBS") 28 positioned between the projection lens 31 and the projection lens 31.

The first and second FELs 4 and 6 divide the white light emitted from the light source 2 in units of cells to be focused on a specific portion of the PBS array 7. The PBS array 7 separates incident light into linearly polarized light having any one optical axis, that is, P wave and S wave so that the S wave is emitted as it is, and the P wave is half-wave plate partially attached to the rear surface of the PBS array 7 ( (Not shown) is converted into an S wave to be emitted. The condenser lens 8 prevents light from being emitted from the PBS array 7 and incident on the first dichroic mirror 10.

The first dichroic mirror 10 reflects and transmits incident light according to the wavelength band to separate the incident light. For example, the first dichroic mirror 10 reflects blue and red light of incident light and transmits green light. The green light separated by the first dichroic mirror 10 proceeds to the first rotating prism 16.

The second dichroic mirror 12 transmits blue light and reflects red light among the blue and red light that is reflected by the first dichroic mirror 10 and is incident. The red light separated by the second dichroic mirror 12 proceeds to the second rotating prism 18.

The first total reflection mirror 14 passes through the second dichroic mirror 12 to reflect the incident blue light to the third rotating prism 20.

The first to third rotating prisms 16, 18, and 20 have a rectangular shape, and each of the rotating prisms 16, 18, and 20 is positioned on an optical path of green, red, and blue light. Each of the rotating prisms 16, 18, and 20 serves to sequentially image red, green, and blue light incident on the display device 30. To this end, each of the rotating prisms 16, 18, and 20 are rotated sequentially at time intervals. As a result, red, green, and blue light are scrolled sequentially on the display element 30.

The green light transmitted through the first rotating prism 16 is totally reflected by the second total reflection mirror 22, and passes through the third and fourth dichroic mirrors 24 and 26 and enters the PBS 28. The red light transmitted through the second rotating prism 18 is reflected by the third dichroic mirror 24 and transmitted through the fourth dichroic mirror 26 to enter the PBS 28. The blue light transmitted through the third rotating prism 20 is reflected by the fourth dichroic mirror 26 and is incident on the PBS 28.

The PBS 28 reflects the blue, red, and green light of the incident S-wave component to the display element 30. The display device 30 is a reflective display device and converts the light reflected from the PBS 28 into incident P-polarized light according to an image signal. The projection lens 31 enlarges and projects the light emitted from the PBS 28 onto the screen to implement an image.

As described above, the first to third rotation prisms 16, 18, and 20 are disposed in the paths of red, green, and blue light so that red, green, and blue light are imaged on the display element 30 at equal intervals.

The first to third rotating prisms 16, 18, and 20 each have a unique refractive index. As shown in FIG. 2, the first to third rotating prisms 16, 18, and 20 exhibit a prism effect in which red, green, and blue light are dispersed in the prism. In other words, the red, green, and blue light incident on the prism by the prism effect have different refractive angles in the prism. As a result, the red, green, and blue light have different propagation paths within the prism. That is, optical path length differences are generated in the red, green, and blue light via the first to third rotating prisms 16, 18, and 20. Due to the optical path difference, the light amounts of the red, green, and blue light are not all transmitted to the display device 30, thereby reducing the light efficiency.

In addition, while the first to third rotating prisms 16, 18, and 20 rotate at high speed, the positions of the red, green, and blue light that are formed in the display element 30 vary according to the rotation angle thereof. In this case, as the rotation angles of the first to third rotating prisms 16, 18, and 20 are linearly changed, positions of the red, green, and blue light that are formed in the display element 30 are linearly spaced at equal intervals. Only when the change, the red, green, blue image signal is sequentially implemented at one position of the display element 30. However, red, green, and blue light formed in the display device 30 according to the rotation angles of the first to third rotation prisms 16, 18, and 20 due to different refraction angles in the rotation prism according to the wavelengths of red, green, and blue. The position of does not change linearly. That is, red, green, and blue light are not scrolled at equal intervals on the screen of the display device 30 according to the rotation angles of the first to third rotation prisms 16, 18, and 20. As a result, it becomes difficult to implement a desired color on the screen of the display device 30, which makes it difficult to implement an image. In addition, in the case of using the rotating prism, not only a large number of optical parts enter, but also the cost of the rotating prism is high.

Accordingly, an object of the present invention is to provide a color scrolling apparatus of a projector using a single plate display device for improving the light efficiency.

1 is a view showing a single plate display device including a conventional color scrolling device.

2 is a view showing an optical path of the rotating prism shown in FIG.

3 is a diagram illustrating a single plate display device including a color scrolling device according to an exemplary embodiment of the present invention.

FIG. 4 shows the color scrolling device shown in FIG. 3; FIG.

FIG. 5A is a side view of the drum shown in FIG. 3; FIG.

5B is a perspective view of the drum shown in FIG. 3.

FIG. 5C is a front view of the drum shown in FIG. 3; FIG.

6 is a view showing the operation principle of the color scrolling apparatus shown in FIG.

FIG. 7 is a view illustrating a process in which light is scrolled while the color scrolling device shown in FIG. 5 rotates.

<Description of Symbols for Main Parts of Drawings>

2, 32: light source 4, 6, 34, 36: FEL

7, 37: PBS array 8, 38: condenser lens

10, 12, 24, 26, 40, 42, 54, 56: dichroic mirror

14, 22, 44, 52: total reflection mirror 16, 18, 20: rotating prism

46, 48, 50: color scrolling device 28, 58: PBS

30, 60: display element 31, 62: projection lens

In order to achieve the above object, a color scrolling apparatus of a projector using a single-plate display device of the present invention, a light source for generating light, an optical separation optical system for separating the light source into red, green, blue light, and Photosynthetic optical system for synthesizing the scrolled red, green, blue light with drums for scrolling the red, green, blue light by transmitting and blocking the red, green, blue light on the optical path of red, green, blue light It is characterized by including the.

The drum is disposed on an optical path and has sidewalls for blocking incident light and at least one opening for transmitting the light.

It is provided in the inner space of the side wall of the drum and further comprises a mirror for converting the optical path of the incident light so that the light travels toward the side wall and the opening of the drum.

Other objects and features of the present invention in addition to the above object will be apparent from the description of the embodiments with reference to the accompanying drawings.

Hereinafter, exemplary embodiments of the present invention will be described with reference to FIGS. 3 to 7.

3 illustrates an optical system of a single plate display device including a color scrolling device according to an exemplary embodiment of the present invention.

Referring to FIG. 3, an optical system of a display device according to an exemplary embodiment may include a light source 32 generating light and first and second light sources disposed on an optical path between the light source 32 and the condenser lens 38. 2 FELs 34, 36, PBS array 37, first to fourth dichroic mirrors 40, 42, 54, 56 for transmitting and reflecting light of a specific wavelength band, and rotation angles. First to third scrolling devices 46, 48, and 50 for changing the optical path, and a first total reflection mirror 44 positioned between the second dichroic mirror 42 and the third scrolling device 50. And a second total reflection mirror 52 positioned between the first scrolling device 50 and the third dichroic mirror 54, and positioned between the fourth dichroic mirror 56 and the LCD 60. PBS 58 and projection lens 62 are provided.

The first and second FELs 34 and 36 divide the white light emitted from the light source 32 into units of cells to be focused on a specific portion of the PBS array 37. The PBS array 37 separates incident light into linearly polarized light having one optical axis, that is, P wave and S wave, so that the S wave is emitted as it is, and the P wave is half-wave plate partially attached to the rear surface of the PBS array 37 ( (Not shown) is converted into an S wave to be emitted. The condenser lens 38 prevents light from being emitted from the PBS array 37 and incident on the first dichroic mirror 40.

The first dichroic mirror 40 reflects and transmits incident light according to the wavelength band to separate the incident light. For example, the first dichroic mirror 40 reflects blue and red light of incident light and transmits green light. The green light separated by the first dichroic mirror 40 proceeds to the first scrolling device 46.

The green light transmitted through the first scrolling device 46 passes through the second total reflection mirror 52 and passes through the third and fourth dichroic mirrors 54 and 56 and enters the PBS 58.

The second dichroic mirror 42 transmits blue light and reflects red light among the blue and red light that are reflected and incident from the first dichroic mirror 40. The red light separated by the second dichroic mirror 42 is directed to the second scrolling device 48. The red light transmitted through the second scrolling device 48 is reflected by the third dichroic mirror 54, passes through the fourth dichroic mirror 56, and enters the PBS 58.

The first total reflection mirror 44 reflects the blue light incident through the second dichroic mirror 42 and proceeds to the third scrolling device 50. The blue light transmitted through the third scrolling device 50 is reflected by the fourth dichroic mirror 56 and is incident on the PBS 58.

The PBS 58 reflects the blue, red, and green light of the incident S-wave component to the LCD 60. The LCD 60 is a reflective LCD that converts the light reflected by the PBS 58 and incident to P-polarized light according to an image signal to be emitted. The projection lens 62 enlarges and projects the light emitted from the PBS 58 onto the screen to implement an image.

As shown in FIG. 4, the first to third scrolling devices 46, 48, and 50 may include a drum 50A, a motor unit 50B for driving the drum 50A, and total reflection for changing a traveling direction of light. It consists of the mirror 50C. The drum 50A is rotated by the motor unit 50B and positioned on the optical path to block or advance the light. Here, the structure of the drum 50A viewed from various angles is as shown in FIGS. 5A to 5C. In this case, the drum 50A will have at least one or more openings 68. For example, four openings are formed as shown in FIGS. 5A-5C. The drum 50A consists of a circular rotating plate 64 and an annular side wall 66 extending vertically from the rotating plate 64. The rotating plate 64 is connected to the rotating shaft of the motor unit 50B to rotate by the rotational force from the motor unit 50B. At this time, when the openings 68 of the drum 50A are positioned on the optical paths of green, red, and blue light, the light proceeds. The total reflection mirror 50C is provided at the center of the drum 50A so that light travels to each opening of the drum 50A.

The operation principle of the scrolling device according to the present invention is as follows.

Referring to FIG. 6, in the first scrolling device 46, first to fourth openings 68, 70, 72, and 74 are formed in the annular side wall of the drum. The first scrolling device 46 positioned on the light path of the green light arranges the first to fourth openings 68, 70, 72, and 74 in the green area G. Accordingly, the green light incident on the first scrolling device 46 travels to the LCD 60 via the first and second openings 68 and 70 of the annular side wall.

The second scrolling device 48 has first to fourth openings 76, 78, 80, 82 formed in the annular side wall of the drum. The second scrolling device 48 positioned on the optical path of red light arranges the first to fourth openings 76, 78, 80, and 82 in the red region R. FIG. Accordingly, the red light incident on the second scrolling device 48 is incident on the LCD 60 via the first and second openings 76 and 78.

Similarly, the third scrolling device 50 has first to fourth openings 84, 86, 88, and 90 formed in the annular side wall of the drum. The third scrolling device 50 positioned on the optical path of blue light arranges the first to fourth openings 84, 86, 88, and 90 in the blue area B. FIG. Accordingly, the blue light incident on the third scrolling device 50 is incident on the LCD 60 via the first and second openings 84 and 86.

As a result, as shown in FIG. 5, green, red, and blue light are sequentially formed on the LCD 60 by the first to third scrolling devices 46, 48, and 50 at equal intervals.

The motor unit rotates the first to third scrolling devices 46, 48, and 50 simultaneously in the same direction. As the first scrolling device 46 rotates in the direction in which the motor unit rotates, the green light formed on the LCD 60 also moves in the rotation direction. As a result, as the first scrolling device 46 rotates, the area of the green light formed in the LCD 60 is reduced by the first opening 68, and the green light proceeds by the third opening 72. On 60, a green light region appears below the blue light. Similarly, as the second and third scrolling devices 48 and 50 rotate, the positions of the red light and the blue light formed on the LCD 60 are rotated in the direction in which the second and third scrolling devices 48 and 50 rotate. Will move. In other words, as shown in FIG. 6, as the motor unit rotates counterclockwise, the area of the green light formed on the LCD 60 is reduced, and the positions of the red and blue light move upwards, and the area of the green light is below the blue light. Will be created. As such, as the first to third scrolling devices 46, 48, and 50 rotate, green, red, and blue light are sequentially scrolled in any pixel cell of the LCD 60. The same may be applied to the case where a display element other than the LCD 60 is used.

As described above, the color scrolling device of the single plate display device according to the present invention can improve the light efficiency than when using a conventional rotating prism. In addition, the manufacturing cost can be reduced, and the optical arrangement can be easily performed to achieve color implementation. The color scrolling device of the single display device according to the present invention does not need to consider the problem of the prism effect that has been a problem using the conventional rotating prism. Furthermore, the rotation angle of the color scrolling device and the position of the color formed on the LCD may be linearly changed to facilitate color implementation.

Those skilled in the art will appreciate that various changes and modifications can be made without departing from the technical spirit of the present invention. Therefore, the technical scope of the present invention should not be limited to the contents described in the detailed description of the specification but should be defined by the claims.

Claims (7)

A light source for generating light, An optical separation optical system for separating the light source into red, green, and blue light; First to third drums for scrolling the red, green, and blue light by transmitting and blocking the red, green, and blue light while rotating on the optical path of the red, green, and blue light; And a photosynthetic optical system for synthesizing the scrolled red, green, and blue light. The method of claim 1, The first to third drums A side wall disposed on the optical path and configured to block incident light; And at least one opening for transmitting the light, wherein the projector is a color scrolling device using a single plate display device. The method of claim 2, And a mirror installed in the inner space of the sidewalls of the first to third drums to convert an optical path of the incident light so that light travels toward the sidewalls and the openings of the first to third drums. Color scrolling device of a projector using a display element. The method of claim 1, And a rotation driving part connected to the first to third drums to rotate the first to third drums. The method of claim 2, And the first to third drums are rotated such that the openings have different positions. The method of claim 1, The optical separation optical system A first mirror unit positioned between the light source and the first drum to separate the red light; A second mirror unit positioned between the light source and the second drum to separate the blue light; And a third mirror unit disposed between the light source and the third drum to separate the green light. The method of claim 5, The photosynthetic optical system A fourth mirror unit positioned between the first drum and the liquid crystal panel to synthesize red light; A fifth mirror unit positioned between the second drum and the liquid crystal panel to synthesize blue light; A sixth mirror unit positioned between the third drum and the liquid crystal panel to synthesize green light; And a prism for synthesizing the red, green, and blue light from the fourth to sixth mirror parts.