JP2000028960A - Projector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make a projector compact by making a three-color successive color filter have rotatable annular structure and providing a reflection mirror whose reflection surface is inclined to incident light from a light source at the center of the color filter. SOLUTION: The red, green and blue filters 2 to 4 are annularly and rotatably connected like a ring as a red, blue and green optical color filter 30 on a belt-like film. Then, the filter 30 is rotated and moved in the frame timing of a video signal. The mirror 5 to which specified inclination is given and which reflects luminous flux from the light source 1 is provided at the center of the filter 30. The direction of the luminous flux transmitted through the filter 30 is changed to a different direction by the mirror 5. A reflection type video element 6 outputs reflected light corresponding to the video signal combined with the filter 30 synchronizing with the frame timing of the video signal to the luminous flux from the light source 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a projector using a frame sequential color filter, and more particularly to a projector using an annular color filter suitable for miniaturization.

[0002]

2. Description of the Related Art In recent years, projectors which project a single-color image of three colors in a frame sequence using a color filter and display the same as a full-color image on a screen have come to be seen.

A first conventional example of these projectors will be described with reference to FIG. In the figure, a light beam emitted from a light source 1 passes through a filter 11 composed of a red filter 8, a green filter 9, and a blue filter 10 rotating at a rotation speed three times as high as the video signal, and is reflected by a mirror 5. The light is reflected by the reflective image element 6 according to each color, enlarged by the lens 7 and projected on a screen (not shown).

In the first prior art, the reflection type picture element 6 displays a red frame image in a liquid crystal dot unit with a degree of reflection in a unit of a frame, and a light beam emitted from the light source 1 is a red filter. 8 illuminates the reflective video element 6 as red monochromatic light, and illuminates the screen with a red frame image. Subsequently, the reflection type image element 6 displays the frame image for green color in a liquid crystal dot unit with a reflection degree, and the luminous flux emitted from the light source 1 irradiates the reflection type image element 6 as green monochromatic light by the green filter 8. Then, a green frame image is projected on the screen. Further, the reflection type image element 6 displays a frame image for blue with a reflection degree for each liquid crystal dot. , A blue frame image is illuminated on the screen. Thus, a frame image three times as large as the video signal can be reflected by the reflective video element 6, and the filter 11 rotating at a triple speed synchronized with the frame image of the video signal results in three-color synthesis on the screen. A color image can be visually recognized.

As a second conventional example of such a projector, Japanese Patent Laid-Open No. 4-54093 discloses a liquid crystal projection display device. According to this publication, a liquid crystal projection display device that uses a transmission type or reflection type matrix panel as a light valve to project a high-quality image, as shown in FIG. The signal is input to the processing and synchronous reproduction circuit 18, is converted into a 3 × video signal, is subjected to phase inversion processing for each field required for driving the liquid crystal, and is input to the liquid crystal driving circuit 19 and the rotation driving circuit 20. The liquid crystal drive circuit 19 performs an X, Y shift register driving the liquid crystal panel as the liquid crystal light valve 22 based on the video signal, and a clock and TV scan to the X, Y shift register based on the synchronization signal from the circuit 18. It is composed of a synchronous control circuit for generating a combined data signal. The X and Y shift registers output X and Y gate signals in synchronization with the horizontal and vertical scanning periods of the video signal according to the data signal, and thereby apply a voltage corresponding to the video signal to the liquid crystal panel.

Further, the rotation drive circuit 20 generates a signal 20a for rotationally driving the color filter 17 based on the synchronization signal from the circuit 18, and rotationally drives the roller 21 with the signal 20a. The color filter 17 is wound around the roller 21, and the color filter 17 is rotated by the rotation of the roller 21. Color filter 17
The red, green, and blue filters 17R and 17G separate red, green, and blue pixels corresponding to the pixels of the transmissive liquid crystal light valve 22 one by one for each pixel of the liquid crystal light valve 22. , And the blue filter portion 17B, and are wound around the roller 21 in the form of, for example, an endless tape. The liquid crystal light valve 2 is almost in contact with the plane of the liquid crystal light valve 22 so that the magnetic head traces the tape.
2 slide on.

As described above, in the present projection apparatus, the liquid crystal light valve 22 forms an image for three fields in one field period. The color filter 17 moves so that the red filter portion 17R, the green filter portion 17G, and the blue filter portion 17B are positionally synchronized with the image formation for three fields of the liquid crystal light valve 11.
Thus, three pieces of color information are projected on one pixel of the liquid crystal light valve 22 in one field period, and the pixel density of the liquid crystal light valve 22 is not reduced.
It is stated that an image can be projected on the screen 16 via the magnifying lens 15 and the image quality is equivalent to that of a three-plate type projector.

[0008]

However, these projectors use a circular color filter as shown in FIG. 2 and an endless tape-like filter as shown in FIG. There is a problem that is difficult.

Particularly, in the conventional example shown in FIG. 3, since the light source, the transmissive liquid crystal light valve and the projection lens are formed in a straight line, even if a tape-shaped color filter is used, the thickness can be reduced to some extent. Due to the optical path length on a straight line, miniaturization was limited.

In order to achieve the miniaturization of the projector, the present invention uses a ring-shaped color filter, forms a monochromatic image of three colors in frame sequence, and arranges the reflecting mirror inclined at the center thereof. It is an object of the present invention to provide a reflection type image element receiving the reflected light of the above and a projection lens to project the light onto a projection screen.

[0011]

According to the present invention, a light beam emitted from a light source is color-selected by a color filter, and the selected color light beam is projected on a reflection type image element to be applied to the reflection type image element. In a projector, a reflected color light beam according to a signal is enlarged by a lens and combined with a screen, the color filter is a frame-sequential color filter, and has a rotatable annular structure including red, green, and blue filters. Is provided with a reflecting mirror at the center of which is inclined with respect to the incident light from the light source.

Further, in the above projector, the reflection type image element and the red, green and blue filters of the color filters are driven in frame synchronization at three times the speed of the image signal.

In the above projector, the reflective image element is driven by dividing the image signal into three frames of three primary color signals of red, green and blue, and the red, green and blue filters of the color filters are It is characterized in that the video signal is rotated and moved for each frame at a frame synchronization rate of 3 times the video signal.

The present invention also provides a light source, a rotatable annular color filter, and a reflecting mirror disposed at the center of the color filter and having a reflecting surface inclined with respect to incident light from the light source. It is characterized by comprising a reflection type image element for receiving the light emitted from the reflection mirror, and a projection lens for projecting a reflection image signal from the reflection type image element.

[0015]

Embodiments of the present invention will be described in detail with reference to the drawings.

[Configuration of the Embodiment] An embodiment of the present invention will be described in detail with reference to FIG.

In FIG. 1, reference numeral 1 denotes a light source which emits white light. A xenon lamp, a metal halide lamp, and the like are accommodated in a parabolic reflecting mirror to secure a strong amount of parallel light. To make the linear lamp emit light like a point light source so that this parallel light is emitted in the color filter direction,
A parabolic parabolic reflector may be provided on the back of the lamp, or a hyperbolic or elliptical reflector may be used. Reference numeral 2 denotes a red filter, reference numeral 3 denotes a green filter, and reference numeral 4 denotes a blue filter. The red, blue, and green optical color filters 30 on the belt-like film are connected to each other in an annularly rotatable manner. The optical color filter 30 is rotated and moved in accordance with the frame timing of the video signal.

Reference numeral 5 denotes an annular optical color filter 3.
A mirror arranged at the center of 0 to reflect the light beam from the light source 1 and has a predetermined inclination to change the light beam transmitted through the color filter 30 in a different direction. Reference numeral 6 denotes a reflection type image element, which outputs reflected light corresponding to the image signal with respect to the light beam from the light source 1 in cooperation with the optical color filter 30 in synchronization with the frame timing of the image signal. In this case, by arranging the reflective image element 6 above the annular color filter 30, the size can be further reduced. Reference numeral 7 denotes a magnifying projection lens which projects the reflected light of the video signal formed by the reflective video element 6 onto a flat screen (not shown). The magnifying projection lens 7 may use a non-linear lens in order to correct distortion particularly at the peripheral portion of the screen.

[Operation of the Embodiment] The operation of the embodiment will be described with reference to FIG.

Light emitted from the light source 1 passes through the red filter 2 in a certain frame, is reflected by the mirror 5, is reflected as a red image by the reflective image element 6, and is projected through the lens 7.
During this time, the annular color filter 30 is moving, and a green image is projected in the next frame, and a blue image is projected in the next frame.

In this case, assuming that the video signal is displayed in units of one frame and the reflection type video element 6 is a reflection type liquid crystal video element, one frame of the video signal is separated into three frames of red, green and blue at high speed. Drive. In synchronization with the video signals of the three frames of red, green and blue, one of the three frames
The red, green, and blue light fluxes selected by the red filter 2, green filter 3, and blue filter 4 of each color filter for each frame are reflected three-dimensionally by the reflecting mirror 5, and are reflected by the reflective video element 6. Is projected to Reflective image element 6
In the case where the projected light beam is red, it is driven by a red video signal, so that the reflected light quantity of the reflective liquid crystal video element 6 is output at a level corresponding to the red luminance level.

The amount of light reflected by the reflective liquid crystal image element 6 is enlarged by a projection lens 7 and combined on a screen. The other green and blue colors are similarly combined on the screen, and three frames of three colors are combined in one frame period of the video signal. A color image can be visually recognized regardless of whether it is an image or a moving image.

Here, since the optical path from the light source 1 to the projection lens 7 forms a three-dimensional Z-shaped optical path which is not on a plane, a reflection type liquid crystal image is formed in an annular column of a small annular color filter 30. By accommodating the element 6 and the projection lens 7, it is possible to significantly reduce the size.

The reflection type liquid crystal image element 6 may be a reflection type liquid crystal panel provided with a micro lens of a TFT type, or a liquid crystal panel using a micro reflection mirror for each TFT type TFT element. May have been used.

In order to reduce the size of the projector, the above embodiment shows an example in which the optical path from the light source to the projection lens has a three-dimensional Z shape instead of a planar Z shape. Further, by giving an optical path to the M shape to which a reflecting mirror is added, it is possible to further reduce the three-dimensional shape.

[0026]

According to the present invention, since the color filters are formed in a ring shape, the size of the main body can be reduced as compared with a conventional circular filter as shown in FIG. Also,
Since the reflection mirror that forms the optical path is used by using a reflection type image element such as a liquid crystal, the optical structure is small and simple, and the overall structure is small and simple.

[Brief description of the drawings]

FIG. 1 is a conceptual configuration diagram of an embodiment according to the present invention.

FIG. 2 is a conceptual configuration diagram of a projector according to a conventional example.

FIG. 3 is a conceptual configuration diagram of a projector according to a conventional example.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 light source 2, 8 red filter 3, 9 green filter 4, 10 blue filter 5 mirror 6 reflective image element 7 lens 11, 17, 30 filter 12 light source 16 screen 20 rotation drive device 22 liquid crystal light valve

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H04N 9/31 H04N 9/31 CB F-term (Reference) 2H048 AA01 AA12 AA19 AA26 5C060 AA07 BA03 BA09 BB13 BC05 BD02 BE05 BE10 EA01 GA01 GB06 HC01 HC16 HC19 HD02 HD05 JB00 5C065 AA07 BB42 CC01 EE02 EE06 EE11 EE20 FF02 5G435 AA18 BB12 BB16 BB17 CC12 DD02 DD04 GG02 GG08 GG12 LL15

Claims (5)

[Claims] 1. A light beam emitted from a light source is color-selected by a color filter, and the selected color light beam is projected on a reflection type image element to generate a reflection color light beam corresponding to an image signal applied to the reflection type image element. In a projector which is magnified by a lens and coupled to a screen, the color filter is a frame-sequential color filter and has a rotatable annular structure including red, green and blue filters, and a reflection surface is provided at the center of the color filter. A projector provided with a reflecting mirror that is arranged to be inclined with respect to incident light from the light source and reflects in the direction of the reflective image element. 2. The reflection-type image element and the red, green and blue filters of the color filters are driven at a frame synchronization rate of 3 times the video signal.
The projector according to 1. 3. The reflection type image element is driven by dividing the image signal into three frames of three primary color signals of red, green and blue, and the red, green and blue filters of the color filter are
3. The projector according to claim 1, wherein the projector is rotated and moved for each frame at a frame synchronization rate of 3 × of the video signal. 4. 4. A light source, a rotatable annular color filter, and a reflecting mirror disposed at the center of the color filter and having a reflecting surface inclined with respect to incident light from the light source.
A projector, comprising: a reflective video element that receives light emitted from the reflector; and a projection lens that projects a reflected video signal from the reflective video element. 5. The projector according to claim 4, wherein an optical path from the light source to the projection lens is a Z-shaped optical path.