JP2009204970A - Projection image display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To clearly project vertical and horizontal lines on a screen at the same level. <P>SOLUTION: The projection image display device includes: dichroic mirrors 4a, 4b and 4c provided on an optical axis between a lamp 2 and an image display panel 5, for selectively reflecting red light, green light and blue light of light emitted by the lamp 2; a pixel display part 7 provided in the image display panel 5 and provided with two or more rows of alternately arranged two-color pixel columns for which two image elements among an image element 7a where the red light is made incident, an image element 7b where the green light is made incident and an image element 7c where the blue light is made incident are repeatedly arranged as a unit in a column direction and one-color pixel columns for which the image element other than the two image elements are repeatedly arranged between the two image elements in the two-color pixel column direction; and a microlens array 6 provided in the image display panel 5, for condensing the red light, the blue light and the green light reflected by the dichroic mirrors 4a, 4b and 4c to the image elements 7a, 7b and 7c for the respective colors. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a projection type image display apparatus that projects an image formed by irradiating an image display panel with light including red light, green light, and blue light on a screen.

  Generally, the projection type image display apparatus includes a three-plate type image display apparatus that projects a color image by three image display elements, and a single-plate type image display apparatus that projects a color image by one image display element. is there.

  The three-plate image display device splits white light output from a single light source into three primary colors of red, blue, and green using a dichroic mirror, and each of the three primary light is incident on three liquid crystal display elements. Thus, a color image is obtained, and this color image is enlarged and projected onto the screen using a single projection lens.

  However, the three-plate type image display apparatus has a problem of high cost due to an increase in the size of the apparatus and an increase in the number of parts.

  On the other hand, the single-panel image display device separates white light output from a single light source with a color filter of three primary colors of red, blue, and green, which is configured in a liquid crystal display element, to obtain a color image. The color image is enlarged and projected onto the screen using a single projection lens.

  However, in such a single-plate image display device, about 2/3 of the light emitted from the light source to the liquid crystal display element is absorbed by the color filter provided in the liquid crystal display element, and the remaining about 1 Since only the light from the light source is used, the projected image becomes dark.

Therefore, Patent Document 1 discloses a microlens array corresponding to liquid crystal display elements arranged in a horizontal row as a set of three primary colors of red, blue, and green on a transparent substrate on the light incident side of the liquid crystal display element. And a first optical system having an action of splitting white light from a light source into three primary colors of red, blue, and green between the condenser lens system and the liquid crystal display element, A projection type in which a light beam is incident on a microlens array from different predetermined directions and a liquid crystal display element is irradiated via a second optical system having a function of condensing the light beam at a position corresponding to the pixel arrangement of the liquid crystal display element. Color liquid crystal display devices have been proposed.
JP-A-6-308492

  However, in the projection type color liquid crystal display device described in Patent Document 2, the liquid crystal display elements are arranged in a horizontal row with the three primary colors of red, blue, and green as a set on the transparent substrate on the light incident side. Therefore, the resolution in the horizontal direction is lower than the resolution in the vertical direction, and the vertical line displayed on the screen appears more blurry to the user than the horizontal line displayed on the screen.

  Further, in such a projection type color liquid crystal display device, in order to match the vertical resolution with the horizontal resolution, the horizontal resolution pitch must be arranged to be 1/3 of the vertical direction. Don't be. For this reason, it becomes difficult to manufacture the image display element, and the defective rate in manufacturing increases, resulting in high costs.

  The present invention has been made in view of the above problems, and provides a projection-type image display device that displays the vertical and horizontal lines of an image projected on a screen with the same structure and with the same clarity. Objective.

  In order to achieve the above object, a first feature of the projection-type image display device according to the present invention is an image formed by irradiating the image display panel (5) with light including red light, green light, and blue light. Is a projection type image display device (1) for projecting the light onto the screen (13), the light emitting means (2) for emitting the light, and between the light emitting means (2) and the image display panel (5) A first optical system (4a, 4b, 4c) which is provided on the optical axis and selectively reflects red light, green light and blue light among the emitted light, and the image display panel (5) Of the image element (7a) to which the red light is incident, the image element (7b) to which the green light is incident, and the image element (7c) to which the blue light is incident. A two-color pixel row arranged repeatedly in the column direction in units of A pixel display section (7) in which a one-color pixel column in which image elements other than the two image elements are repeatedly arranged between the two image elements in the color pixel column direction is alternately arranged in a plurality of rows; and the image display The image light (7a, 7b, 7c) is provided for each color of red light, blue light, and green light provided in the panel (5) and reflected by the first optical system (4a, 4b, 4c). And a second optical system (6) for condensing the light.

  In order to achieve the above object, a second feature of the projection-type image display device according to the present invention is provided on the optical axis between the image display panel (5) and the screen (13), and the image display A reflection plate (9) for reflecting the image light transmitted through the section (7), and the image for one frame is divided into two, and the first sub-frame image and the second sub-frame image divided into two are An image signal generator (12) for generating a sub-frame image signal to be projected on the screen (11) at a frequency twice the frequency corresponding to the image for one frame; and the second sub When the sub-frame image signal for projecting the frame image is supplied, the vertical scanning on the screen (11) is performed with respect to the position of the first sub-frame image projected on the screen (11). The second sub-frame image is projected to a position moved in the horizontal and / or horizontal scanning direction by a distance approximately half the distance between the adjacent image elements of the same color on the screen (11). And a reflector control unit (10) for controlling the reflector (9).

  According to the projection type image display apparatus of the present invention, the vertical and horizontal lines of the image projected on the screen can be displayed as clearly as possible with a simple structure.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

<Configuration of Projection Type Image Display Device>
FIG. 1 is a configuration diagram showing a configuration of a projection type image display apparatus according to the present embodiment.

  The projection type image display apparatus 1 according to the present embodiment includes a lamp 2, a field lens 3, three dichroic mirrors 4a to 4c, an image display panel 5, an image signal generation unit 8, a reflecting plate 9, A controller 10, a drive unit 11, projection lenses 12a and 12b, and a projection screen 13 are provided.

  The lamp 2 emits white light including red light, green light, and blue light, and the field lens 3 refracts the white light emitted from the lamp 2 into parallel light.

  The dichroic mirrors 4a to 4c selectively reflect red light, green light, and blue light according to the wavelength of light out of the white light converted into parallel light by the field lens 3. The dichroic mirrors 4 a to 4 c are fixed at such angles that the reflected red light, green light, and blue light are incident on the microlens array 6.

  The image display panel 5 includes a microlens array 6 and an image display unit 7, and the microlens array 6 is fixed to the red light, green light, and blue light incident sides of the image display unit 7.

  In the microlens array 6, microlenses 6a having a convex shape are regularly arranged on the incident side of red light, green light, and blue light reflected by the dichroic mirrors 4a to 4c. The microlens array 6 is provided in the image display unit 7 for each color of red light, blue light, and green light reflected by the dichroic mirrors 4a to 4c by refraction of light by the microlens 6a. The light is condensed on the image elements of the respective colors.

  The image display unit 7 collects the image element that receives the red light collected by the microlens array 6, the image element that receives the green light collected by the microlens array 6, and the microlens array 6. The image elements on which the emitted blue light is incident are regularly arranged.

  FIG. 2 is a front view of the image display panel 5.

  As shown in FIG. 2, the image element 7a to which the red light condensed by the microlens 6a is incident and the image element 7b to which the green light condensed by the microlens 6a is incident are set as one set. A set of image elements 7a and 7b is repeatedly and regularly arranged as a two-color pixel array.

  In addition, the image element 7c on which the blue light condensed by the microlens array 6 is incident is repeatedly and regularly arranged as a one-color pixel array between the image element 7a and the image element 7b in the two-color pixel array direction. Yes.

  Further, the two-color pixel column and the one-color pixel column are alternately arranged in a plurality of rows.

  Then, the image display unit 7 determines the amounts of red light, green light, and blue light transmitted through the image elements 7a, 7b, and 7c based on a sub-frame image signal supplied from an image signal generation unit 8 described later. By adjusting, image light is generated.

  As shown in FIG. 2, the microlens array 6 includes a microlens 6a so as to cover the image elements 7a, 7b, and 7c, and the red light and blue light reflected by the dichroic mirrors 4a to 4c. Light and green light are condensed on the image elements 7a, 7b, and 7c provided in the image display unit 7 for each color.

  As described above, the red light, the green light, and the blue light reflected by the dichroic mirrors 4a to 4c are condensed on the image elements 7a, 7b, and 7c for each color by the microlens array 6, and the condensed red light is collected. The light, green light, and blue light are transmitted by the image display unit 7 so that the amount of light transmitted is adjusted, and image light to be projected onto the screen 13 described later is generated.

  The image signal generation unit 8 divides the image for one frame into two, and the two divided first subframe image and second subframe image are double the frequency corresponding to the image for one frame. A sub-frame image signal to be projected on the screen is generated at a frequency of. Then, the image signal generation unit 8 alternately generates a subframe image signal for projecting the first subframe image and a subframe image signal for projecting the second subframe image. 10 and supply.

  Here, the sub-frame image signal for projecting the first sub-frame image and the sub-frame image signal for projecting the second sub-frame image are equal to half the number of data of one frame image. Is generated as follows. For example, an odd-numbered image of a one-frame image may be a first sub-frame image, and an even-numbered image of a one-frame image may be a second sub-frame image. Alternatively, the first sub-frame image or the second sub-frame image may be alternately divided and generated.

  The reflection plate 9 is driven at a high frequency by the drive unit 11 described later, and reflects the image light transmitted through the image display unit 7.

  Based on the sub-frame image signal supplied from the image signal generation unit 8, the controller 10 sends a control signal for driving the reflecting plate 9 to the reflecting plate position 9 a or the reflecting plate position 9 b to the driving unit 11. Supply.

  The drive unit 11 drives the reflector 9 based on the control signal supplied from the controller 10.

  FIG. 3 is a perspective view showing the reflector 9 and the drive unit 11.

  As shown in FIG. 3, a reflecting plate support shaft 9 c is attached in a diagonal direction of the reflecting plate 9, and the reflecting plate support shaft 9 c rotates about the axis P as a rotating shaft. Also, the axis P is rotated about the rotation axis.

  The drive unit 11 includes a drive unit main body 11 a and a drive shaft 11 b, and one end of the drive shaft 11 b is fixed to the reflection plate 9.

  The drive unit body 11a drives the drive shaft 11b back and forth with respect to the direction of the drive shaft Q based on the control signal supplied from the controller 10, and the reflector 9 fixed to the drive shaft 11b is It rotates about the axis P as a rotation axis. Thereby, the drive part 11 can drive the reflecting plate 9 so that it may become the reflecting plate position 9a or the reflecting plate position 9b.

  The projection lenses 12 a and 12 b are lenses for enlarging the image light reflected by the reflecting plate 9 in accordance with the size of the screen projected onto the projection screen 13.

  The projection screen 13 is a screen for displaying the image light enlarged by the projection lenses 12a and 12b.

<Operation of Projection Type Image Display Device>
Hereinafter, the operation of the projection type image display apparatus 1 which is Embodiment 1 of the present invention will be described with reference to FIG.

  White light including red light, green light, and blue light emitted from the lamp 2 as the outgoing optical axis R enters the field lens 3 while spreading. The incident white light is refracted by the field lens 3 so as to be parallel to the outgoing optical axis R, and transmitted or reflected by the dichroic mirrors 4a to 4c.

  As described above, since the dichroic mirrors 4a to 4c selectively reflect red light, green light, and blue light in accordance with the wavelength of the light among the white light, the red light is reflected by the dichroic mirror 4a. , Enters the microlens array 6. The green light transmitted through the dichroic mirror 4 a is reflected by the dichroic mirror 4 b and enters the microlens array 6. Further, the blue light transmitted through the dichroic mirror 4 b is reflected by the dichroic mirror 4 c and enters the microlens array 6.

  The red light, green light, and blue light incident on the microlens array 6 are refracted by the microlens 6a provided on the surface of the microlens array 6, and the image elements 7a, 7b, 7c.

  The image display unit 7 is based on the subframe image signal for projecting the first subframe image supplied from the image signal generation unit 8, and the image element 7 a for incident red light, green light, and blue light. , 7b, 7c are adjusted so that they are transmitted as image light for projecting the first sub-frame image. Similarly, the image display unit 7 receives incident red light, green light, and blue light based on the subframe image signal for projecting the second subframe image supplied from the image signal generation unit 8. The amount of light transmitted through the image elements 7a, 7b, and 7c is adjusted and transmitted as image light for projecting the second sub-frame image.

  The image light transmitted from the image display unit 7 is reflected by the reflecting plate 9 driven by the driving unit 11 and enters the projection lens 12a.

  When the controller 10 is supplied with a subframe image signal for projecting the second subframe image, the controller 10 controls the position of the first subframe image projected on the projection screen 13 on the projection screen 13. In the vertical scanning direction and the horizontal scanning direction, with respect to a distance that is half the distance between adjacent image elements of the same color on the projection screen 13, that is, the position of the first sub-frame image projected on the projection screen 13. The reflector 9 is controlled so that the second sub-frame image is projected to a position moved by the distance between the adjacent image elements arranged in the two-color pixel row on the projection screen 13.

  Specifically, the controller 10 determines whether the supplied subframe image signal is a subframe image signal for projecting the first subframe image or a subframe image for projecting the second subframe image. While the sub-frame image signal for determining the signal and projecting the first sub-frame image is supplied, the reflector 9 is controlled to be the reflector position 9a, and the first sub-frame image is controlled. While the sub-frame image signal for projecting is supplied, control is performed so that the reflection plate position 9b is obtained.

  Then, the image light reflected by the reflection plate 9 controlled in this way is magnified by the projection lenses 12 a and 12 b and projected onto the screen 13.

  FIG. 4 is a diagram showing an example of an image projected on the screen 13. 4A shows a first subframe image, FIG. 4B shows a second subframe image, and FIG. 4C shows a one-frame image. Yes.

  As shown in FIG. 4A, the first subframe image is projected on the projection screen 13, and as shown in FIG. 4B, the first subframe shown in FIG. A second sub-frame image is projected at a position shifted from the image by one pixel in the vertical scanning direction and the horizontal scanning direction.

  Then, as shown in FIG. 4C, the first sub-frame image and the second sub-frame image are synthesized on the screen 13, thereby projecting one frame image.

  In the first sub-frame image shown in FIG. 4A, the centers of the red light R1, the green light G1, and the blue light B1 are equally spaced in the vertical scanning direction and the horizontal scanning direction on the projection screen 13. In other words, the second sub-frame image shown in FIG. 4B is projected in the same manner in the vertical scanning direction, and the resolution pitch in the vertical scanning direction and the horizontal scanning direction is the same. The projection is performed so that the resolution pitch in the horizontal scanning direction is the same.

  In this way, the first sub-frame image and the second sub-frame image shifted by one pixel in the vertical scanning direction and the horizontal scanning direction are combined, so that the resolution of the projected image is reduced to the original 1 The resolution of the frame image can be increased by a factor of four.

  As described above, according to the projection-type image display apparatus 1 that is Embodiment 1 of the present invention, the vertical and horizontal lines of the image projected on the projection screen 13 are clearly displayed to the same extent with a simple structure. be able to.

  Note that the controller 10 of the projection type image display apparatus 1 that is Embodiment 1 of the present invention projects the projection onto the projection screen 13 when the subframe image signal for projecting the second subframe image is supplied. A position moved by a half of the distance between adjacent image elements on the projection screen 13 in the vertical scanning direction and the horizontal scanning direction on the projection screen 13 with respect to the position of the first sub-frame image. In addition, the reflector 9 is controlled so as to project the second sub-frame image, but the second sub-frame image is projected to a position moved on the projection screen 13 in the vertical scanning direction or the horizontal scanning direction. In this manner, the reflector 9 may be controlled.

  In this case, by synthesizing the first subframe image and the second subframe image, the resolution of the projected image is artificially doubled relative to the resolution of the original one frame image. be able to.

  In addition, the microlens 6a of the microlens array 6 of the projection type image display apparatus 1 that is Embodiment 1 of the present invention is circular, and has red light, green light, and blue light reflected by the dichroic mirrors 4a to 4c. Although it has a configuration having a convex shape on the incident side, it is rectangular, and has a convex shape on the incident side of red light, green light, and blue light reflected by the dichroic mirrors 4a to 4c. Also good. In other words, the microlens 6a has red light, blue light, and green light reflected by the dichroic mirrors 4a to 4c, and the image elements 7a for each color provided in the image display unit 7 for each color due to light refraction. , 7b, and 7c may be used.

It is the block diagram which showed the structure of the projection type image display apparatus which is this embodiment. It is a front view of the image display panel which comprises the projection type image display apparatus which is this embodiment. It is the perspective view which showed the reflecting plate and drive part which comprise the projection type image display apparatus which is this embodiment. (A) has shown the 1st sub-frame image, (b) has shown the 2nd sub-frame image, (c) has shown the image of 1 frame.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Projection type image display apparatus 2 ... Lamp (light emission means)
3 ... Field lenses 4a to 4c ... Dichroic mirror (first optical system)
5. Image display panel 6. Micro lens array (second optical system)
6a ... micro lens 7 ... pixel display unit 7a, 7b, 7c ... image element 8 ... image signal generation unit 9 ... reflecting plate 10 ... controller (reflecting plate control unit)
DESCRIPTION OF SYMBOLS 11 ... Drive part 12a, 12b ... Projection lens 13 ... Projection screen

Claims (2)

A projection image display device that projects an image formed by irradiating an image display panel with light including red light, green light, and blue light on a screen,
A light emitting means for emitting the light;
A first optical system provided on an optical axis between the light emitting means and the image display panel and selectively reflecting red light, green light, and blue light among the emitted light;
Among the image elements that are provided in the image display panel and receive the red light, the image elements that receive the green light, and the image elements that receive the blue light, two image elements are used as a unit. A two-color pixel column arranged in the direction and a one-color pixel column in which image elements other than the two image elements are repeatedly arranged between the two image elements in the two-color pixel column direction are alternately arranged in a plurality of rows. A pixel display unit,
A second optical system that is provided in the image display panel and collects red light, blue light, and green light reflected by the first optical system on the image element for each color;
A projection-type image display device comprising: A reflection plate provided on an optical axis between the image display panel and the screen and reflecting image light transmitted through the image display unit;
The image for one frame is divided into two, and the first sub-frame image and the second sub-frame image divided into two are divided at a frequency twice the frequency corresponding to the image for one frame. An image signal generator for generating a sub-frame image signal to be projected on the screen;
When the sub-frame image signal for projecting the second sub-frame image is supplied, the vertical scanning direction on the screen with respect to the position of the first sub-frame image projected on the screen And / or the reflector so as to project the second sub-frame image at a position moved in the horizontal scanning direction by a distance approximately half of the distance between the adjacent image elements of the same color on the screen. A reflector control unit for controlling
The projection type image display apparatus according to claim 1, further comprising:

Images