JPH1039240A - Color picture display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To miniaturize a color picture display device by using a single deformable mirror device(DMD), and using a small optical thin film having a color analysis function so as to obtain desired display color. SOLUTION: Parallel white light emitted from a parallel white light source 13 is made incident on each mirror of the DMD 11 at an angle of α1 with the horizontal surface. The mirror 12 whose address is specified by an address signal from a signal separation circuit based on a picture signal is controlled by a mirror inclining operation control circuit in terms of an inclining angle and an inclining holding time by every field cycle. The mirror 12 is inclined at a mirror angle θ for a specified time, so that the parallel white light from the light source 13 is reflected by the mirror 12 and made incident on the optical thin film 14 at the incident angle ϕ=50 deg., the thin film 14 transmits light having a red component, and the red transmitted light passes through an image formation lens 15 and is image-formed on a screen 18 for a specified time.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The deformable mirror device (D)
MD: Deformable Mirror Device or Digital Mi
(Cromirror Divice) is a semiconductor device, which has a small mirror (size: for example, a square and about 16 to 20 μm on one side) on the surface of a device irradiated with incident light for display.
Are two-dimensionally arranged, and each mirror is tilted by electrostatic force according to an image signal to selectively reflect incident light. An image is formed based on reflected light from each tilted mirror of the device. The present invention relates to a color image display device that displays a color image using a deformable mirror device.

[0002]

2. Description of the Related Art Conventionally, as a color image display technique using a deformable mirror device (hereinafter referred to as DMD), a document "O plus E, No. 179 (October 1994)
Mon.), pp. 90-94, "DMD and its application to displays", the following prior arts 1 and 2 are introduced.

FIG. 8 is a diagram showing a configuration of a color image display device as the prior art 1. As shown in FIG. In the figure,
51 is a DMD having a number of mirrors two-dimensionally arranged on the device surface, 52 is a white light source for color display, 53 is a rotating color filter disk rotated by a driving motor (not shown), 54 is a projection lens, 55 is a screen, 56 is a light absorbing plate. The rotating color filter disk 53 is formed in a fan shape with three color filters transmitting only the red, green, and blue components of light, each having a central angle of 120 °. The square mirrors made of the aluminum alloy of the DMD 51 are two-dimensionally arranged to form 768 × 576 pixels in this example.

[0004] The DM of the color image display device having the above-described structure is used.
In D51, a mirror (generally a plurality) at a position corresponding to a display image pattern is specified from all mirrors arranged two-dimensionally based on an image signal in each field cycle (one control cycle). The designated mirror is tilted at a constant angle に 対 し て with respect to the device horizontal surface of the DMD 51, and the rotating color filter disk 53 is tilted.
The tilt holding time of the tilted mirror is controlled to obtain a desired display color using the three primary color lights of red, green, and blue sequentially incident through the mirror. First, the red light radiated by the color display white light source 52 and passed through the red component transmitting filter of the rotating color filter disk 53 is radiated to the DMD 51 and is reflected by each of the inclined mirrors. The red reflected light from each mirror tilted at this angle を 通 is projected onto the screen 55 for the mirror tilt holding time tR through the projection lens 54 to form red component image information in one field cycle.

Next, the rotary color filter disk 53 is rotated in a counterclockwise direction by 120 ° by a driving motor, and is radiated by a white light source 52 for color display.
The green light passing through the green component transmission filter of No. 3 is DM
The light is applied to D51 and is reflected by each of the inclined mirrors. The green reflected light from each mirror tilted at this angle を 通 is projected through the projection lens 54 onto the screen 55 for the mirror tilt holding time tG, and green component image information in one field cycle is formed. Further, the rotating color filter disk 53 is rotated in the counterclockwise direction by 120 °, and the blue light passing through the blue component transmitting filter is applied to the DMD 51 and reflected by the inclined mirrors. The blue reflected light from each mirror tilted at this angle ψ passes through the projection lens 54 to the screen 55 and the mirror tilt holding time t
B is projected to form blue component image information in one field cycle.

Thus, a color image for one field period is obtained. That is, each mirror at a position corresponding to the shape of the image to be displayed is tilted based on the address information of the image signal, and the mirrors for the three primary colors red, green and blue are determined based on the color information of the image signal. The display color is obtained by controlling the ratio of the tilt holding time (tR: tG: tB), and the magnitude (absolute) of each mirror tilt holding time of the three primary color lights based on the luminance information (brightness / darkness information) of the image signal. Value) is controlled to determine the luminance of the image. Since the three primary colors are sequentially reflected at minute time intervals to obtain a display color by color mixture, the field cycle is set to several tens ms or less so as to be sufficiently shorter than the response time of human eyes. . Hereinafter, a series of color images based on the image signals are displayed by repeating the above-described operation for each field cycle.

Next, as a conventional technique 2, there is a technique for displaying a color image using three DMDs. FIG. 9 is a diagram for explaining a schematic configuration of a color image display device as the second related art. As shown in FIG. 1, this conventional color image display device includes a first DMD 61 for emitting red light from a light source 64 for red light, a second DMD 62 for emitting green light from a light source 65 for green light, And a third DMD 63 for allowing blue light to be incident from a light source 66 for blue light, and combining images reflected by the three DMDs 61, 62, and 63 into a single image by an image combining means 67. A color image provided with a desired display color is projected on a screen 68 via a projection optical system (not shown).

[0008]

However, the device of the prior art 1 described above has a disadvantage that the whole device becomes large because a rotating color filter disk and a drive motor for rotating the disk are required. there were. Conventional technology 2
In the device of the prior art, the driving motor as in the device of the prior art 1 is unnecessary, but three sets of a combination of a DMD and a light source for color expression are required, and a large space is required for their arrangement. There is a drawback that the entire device becomes large.

Accordingly, an object of the present invention is to reduce the size of a color image display device that displays a color image using a deformable mirror device (DMD).

[0010]

To achieve the above object, a first color image display device according to the present invention comprises a plurality of mirrors capable of tilting operation to selectively reflect incident light in accordance with an image signal. A color image display device that displays a color image based on the image signal using the deformable mirror device, wherein at least three color stimulus values are applied to each mirror of the deformable mirror device. A light irradiating means for irradiating incident light having a plurality of wavelength components including the wavelength components of the three primary colors to be given; A position corresponding to a display image pattern based on the image signal, with respect to an optical thin film that generates transmitted light, and each mirror of the deformable mirror device. In addition to addressing a mirror, the tilt angle and the tilt holding of the addressed mirror are set so that the incident light is sequentially incident on the optical thin film after the mirror reflection at a specific incident angle according to a display color for each predetermined time. Mirror control means for controlling time, and image formation in which the light reflected by the addressed mirror forms an image of transmitted light from the optical thin film incident at the specific incident angle and displays a color image thereof. And a display means.

A second color image display apparatus according to the present invention includes a deformable mirror device having a plurality of mirrors that can be tilted to selectively reflect incident light in accordance with an image signal, and that the deformable mirror device includes a deformable mirror device. In a color image display device that displays a color image based on the image signal using a mirror device, the deformable mirror device, as each mirror, reflects reflected light of a specific wavelength corresponding to an incident angle on a mirror body surface. A mirror with a thin film formed by forming an optical thin film to be generated, wherein each of the mirrors with a thin film of the deformable mirror device is provided with a plurality of wavelength components including wavelength components of three primary colors giving at least tristimulus values of colors. Light irradiating means for irradiating the incident light having a color, and a mirror with each thin film of the deformable mirror device, based on the image signal While addressing the thin-film mirror at a position corresponding to the display image pattern, the specified thin-film mirror is sequentially irradiated with the incident light at a specific incident angle in accordance with a display color for each predetermined time, Mirror control means for controlling the tilt angle and tilt holding time of the addressed mirror with thin film; and imaging display means for forming an image of the reflected light from the addressed mirror with thin film and displaying a color image thereof. , Are provided.

In the interference of light by an optical thin film having a parallel plane, light having a different refractive index from the surroundings (for example, the atmosphere) and having a multi-wavelength component, such as white light, is applied to an optical thin film made of a dielectric. Is incident at an incident angle φ, the transmitted light and the reflected light from the optical thin film each become light having a specific wavelength (color) corresponding to the value of the incident angle φ. In other words, the optical thin film having a parallel plane shape (parallel flat thin layer) performs a color separation function of extracting transmitted light or reflected light of a specific wavelength from white light.

In the first color image display device, an optical thin film having a parallel plane shape is disposed at a predetermined position with respect to the DMD, and the mirror of the DMD is tilted at a predetermined angle to be incident on the optical thin film. By controlling the incident angle of white light and thereby changing the wavelength component of the transmitted light from the optical thin film, transmitted light having a desired wavelength (color) can be obtained. it can. Further, in the second color image display device, each mirror of the DMD itself has an optical thin film forming a parallel plane, and the mirror with the thin film is inclined at a predetermined angle to make the mirror with the white light incident on the mirror with the thin film. By controlling the incident angle of light and thereby changing the wavelength component of the reflected light from the tilted mirror with a thin film, reflected light having a desired wavelength (color) can be obtained. Color display.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic configuration diagram showing an example of the first color image display device according to the present invention, FIG. 2 is a schematic diagram showing the configuration of the optical thin film shown in FIG. 1, and FIG.
4 is a block diagram showing a mirror control unit of the first color image display device shown in FIG. 4, and FIG. 4 is a diagram for explaining an example of control by the mirror control unit shown in FIG.

In FIG. 1, reference numeral 11 denotes a deformable mirror device (DM) having a mirror 12 two-dimensionally arranged on the surface.
D). Each mirror 12 of the DMD 11 is a thin mirror having a rectangular shape and made of an aluminum alloy, and is a minute mirror capable of tilting operation by electrostatic force.

Numeral 13 denotes a parallel white light source provided with a tungsten lamp (not shown). The parallel white light source 13 as a light irradiating means for expressing colors has an angle formed by an optical axis thereof with the DMD horizontal surface at an angle α1. It is arranged to be. Therefore, the parallel white light from the parallel white light source 13 is incident on each mirror 12 of the DMD 11 at an angle α1 with the horizontal surface of the DMD, that is, when the mirror 12 is in a horizontal state, 12 at an angle .alpha.1.

Numeral 14 denotes an optical thin film having a parallel plane shape disposed above the DMD 11 in the figure, and receives parallel white light reflected by the mirror 12 tilted by a command from a mirror control means 20, which will be described later. , For generating transmitted light of a specific wavelength corresponding to the incident angle φ. The optical thin film 14 has a dielectric parallel plane 1 having a thickness h and a refractive index n.
Metal film 1 having high reflectance of 95% or more on both surfaces of 4a
4b is deposited very thinly (see FIG. 2). In this example, the thickness of the dielectric parallel plane 14a made of transparent glass is h = 0.4 nm, and the refractive index is n =
1.25, and the metal film 14b is a metal film made of aluminum.

Reference numeral 15 denotes an imaging lens, and reference numeral 16 denotes a screen. The transmitted light of a specific wavelength (color) described later transmitted through the optical thin film 14 is guided to the screen 16 through the imaging lens 15, and An image is formed thereon to form a color image. The imaging lens 15 and the screen 16 form an image of the transmitted light transmitted through the optical thin film 14,
The image display means 17 for displaying the color image is constituted.

In FIG. 3, reference numeral 18 denotes a signal separation circuit (decoder), and 19 denotes a mirror tilt operation control circuit.
The signal separation circuit 18 decodes the input image signal,
For each field period T, an address signal designating a mirror at a position corresponding to a required pixel, that is, a mirror at a position corresponding to a display image pattern, in order to create an image shape,
The color information signal and the luminance information signal included in the image signal are supplied to the DMD 11 and the mirror tilt operation control circuit 19.

The mirror tilting operation control circuit 19 obtains a display color specified by the color information signal and the luminance information signal by using the three primary color transmitted lights R, G, and B extracted by the optical thin film 14. A signal for commanding the mirror tilt angle and a signal for commanding the mirror tilt holding time are provided to the DMD 11 for each field period T.

That is, with respect to the addressed mirror, in order to extract the red transmitted light R from the optical thin film 14, the mirror tilt angle θ1 for allowing the parallel white light to enter the optical thin film 14 at an incident angle φ1 after the mirror reflection and the holding thereof. Time t
1. In order to extract the green transmitted light G from the optical thin film 14, the mirror tilt angle .theta.2 and the holding time t2 for allowing the parallel white light to enter the optical thin film 14 at an incident angle .phi.2 after the mirror reflection from the mirror.
And a signal for instructing the DMD 11 a mirror tilt angle .theta.3 and a holding time t3 for allowing the parallel white light to enter the optical thin film 14 at an incident angle .phi.3 after the mirror reflection in order to extract the blue transmitted light B from the optical thin film 14. (See FIG. 4). The display color is determined by the ratio of the three mirror tilt holding times (t1: t2: t3), and the luminance is determined by the magnitude of the mirror tilt holding times t1, t2, and t3.

The signal separation circuit 18 and the mirror tilt operation control circuit 19 address the mirror 12 at the position corresponding to the display image pattern based on the image signal, and the tilt angle and tilt holding time of the addressed mirror 12. Of the mirror control means 20 for performing the above control.

As described above, in this example, the thickness h =
An optical thin film 14 having a refractive index of n = 1.25 is used. The wavelength λ at which the intensity of light transmitted through such an optical thin film 14 becomes maximum is given by the following equation. Here, in the formula, m is an integer (1, 2, 3,...).

[0024]

(Equation 1)

From the relationship between the incident angle φ obtained from the equation and the wavelength λ of the transmitted light, in the visible region, the incident angle φ of the parallel white light =
When the light is transmitted through the optical thin film 14 at 50 °, the wavelength λ =
A red transmitted light R of 0.643 nm is obtained. Also, φ =
At 60 °, green transmitted light G of λ = 0.5 nm is obtained,
It can be seen that when φ = 65 °, blue transmitted light B of λ = 0.423 nm is obtained. These lights correspond to the three primary colors of light that are the color tristimulus values.

The operation of the first color image display device having the above configuration will be described with reference to FIGS. The parallel white light from the parallel white light source 13 is incident on each mirror of the DMD 11 at an angle α1 with respect to the horizontal surface of the DMD. Then, the mirror tilt operation control circuit 19 controls the tilt angle and the tilt holding time of the mirror 12 addressed by the address signal from the signal separation circuit 18 based on the image signal in each one-field period T.

First, the mirror 12 is tilted at the mirror tilt angle θ1 for the time t1 to reflect the parallel white light from the parallel white light source 13, and the parallel white light reflected by the mirror 12 is reflected at an incident angle φ1 = 50 °. When the light enters the optical thin film 14, light having a red component is transmitted through the optical thin film 14, and this red transmitted light R passes through the imaging lens 15 and passes through the screen 16.
It is imaged only during time t1.

Next, the mirror 12 is moved to the mirror inclination angle θ2.
When the parallel white light from the parallel white light source 13 is reflected by inclining the optical thin film 14 by the time t2, and the parallel white light reflected by the mirror 12 is incident on the optical thin film 14 at an incident angle φ2 = 60 °, the optical thin film 14 The light having a green component is transmitted, and the green transmitted light G passes through the imaging lens 15 and passes through the screen 1.
6 is imaged only for a time t2. In addition, mirror 1
2 is tilted at a mirror tilt angle .theta.3 for a time t3 to reflect the parallel white light from the parallel white light source 13, and the parallel white light reflected by the mirror 12 is incident on the optical thin film 14 at an incident angle .phi.3 = 65.degree. And light having a blue component is transmitted through the optical thin film 14, and the blue transmitted light B is transmitted through the imaging lens 1.
5 and is imaged on the screen 16 only for a time t3.

In this way, a color image for one field period in which a desired display color is colored is obtained. By repeating such an operation for each field period, a series of color images based on the image signal is displayed on the screen 16. Can be displayed. Since the three primary color lights R, G, and B are sequentially imaged at minute time intervals to obtain a display color by color mixture, the field period T is set to several tens so as to be sufficiently shorter than the response time of human eyes. ms or less.

Next, the second color image display device will be described. FIG. 5 is a diagram schematically showing the entire configuration of the second color image display device according to the present invention, FIG. 6 is a diagram schematically showing the configuration of the thin-film mirror of the deformable mirror device shown in FIG. 5, and FIG. FIG. 6 is a diagram for explaining an example of control by the mirror control unit shown in FIG.

In FIG. 5, reference numeral 31 denotes a deformable mirror device (DMD) having thin film mirrors 32 two-dimensionally arranged on the surface. Each of the mirrors 32 that can be tilted by the electrostatic force has a light absorber 32b on a square mirror body 32a made of an aluminum alloy in order from the surface,
It is formed by laminating an optical thin film 32c having a parallel plane shape (see FIG. 6). In this example, the optical thin film 32c
1 has a thickness h = 0.4 nm and a refractive index n = 1.25 as in the case of FIG. 1, and a light absorber 32b for absorbing the transmitted light transmitted through the optical thin film 32c is a dielectric multilayer. It consists of a film.

Reference numeral 33 denotes a parallel white light source provided with a tungsten lamp (not shown). The parallel white light source 33 as a light irradiating means for expressing colors has an angle formed by the optical axis thereof with the horizontal surface of the DMD at an angle α1. It is arranged to become. 3
4 is an imaging lens, 35 is a screen, DMD31
Wavelength (color) from mirror 32 with thin film
Is guided to a screen 35 through an imaging lens 34, and forms an image on the screen 35 to form a color image. Imaging lens 34 and screen 3
Reference numeral 5 forms an image display means 36 which forms an image of the reflected light from the mirror 32 with a thin film and displays the color image.

Reference numeral 37 denotes mirror control means. The mirror control means 37 has substantially the same configuration as that shown in FIG. 3 described above. For each mirror 32 with a thin film of the DMD 31, based on an image signal, every one field cycle T,
The mirror with the thin film at the position corresponding to the display image pattern is addressed, and the specified thin-film mirror is sequentially irradiated with the parallel white light from the parallel white light source 33 at a specific incident angle δ according to the display color. The tilt angle and the tilt holding time of the addressed mirror with the thin film are controlled so that the light is incident only for the time.

The operation of the second color image display device having the above configuration will be described with reference to FIGS. As described above, the thin film mirror at the position corresponding to the display image pattern is addressed every one field cycle T, and the tilt angle and the tilt holding time of the addressed thin film mirror 32 are controlled. Done.

First, the parallel white light source 3 is tilted by tilting the mirror 32 with a thin film at the mirror tilt angle η1 for a time t1.
When the parallel white light from No. 3 is incident on the mirror 32 with a thin film at an incident angle δ1 = 50 °, light having a complementary color of red is reflected from the mirror 32 with a thin film. Time t on the screen 35 through the imaging lens 34
Imaged only during 1

Next, by inclining the mirror 32 with the thin film at the mirror tilt angle η2 for the time t2, the parallel white light from the parallel white light source 33 is made incident on the mirror 32 with the thin film at an incident angle δ2 = 60 °. Light having a complementary color of green is reflected from the mirror 32, and the reflected light of the complementary color of green is imaged on the screen 35 through the imaging lens 34 for a time t2. Further, a mirror 32 with a thin film
Is tilted by the mirror tilt angle η3 for the time t3, so that the parallel white light from the parallel white light source 33 is incident at an incident angle δ3 = 6.
When the light enters the mirror 32 with the thin film at 5 °, light having a complementary color of blue is reflected from the mirror 32 with the thin film. An image is formed only during t3.

In this manner, a color image for one field cycle in which a desired display color is colored by the complementary color system is obtained. By repeating such an operation for each field cycle, a series of color images based on the image signal is obtained. An image can be displayed on the screen 35.

[0038]

According to the first color image display device of the present invention, a color image display device using a deformable mirror device (DMD) uses a single DMD and has a color separation function. Since a desired display color is obtained by using a small optical thin film, a large-sized rotating color filter disk with a driving motor is not required, and the apparatus can be downsized compared to the conventional apparatus. . According to the second color image display apparatus of the present invention, a desired display color can be obtained by using a single DMD having a mirror with an optical thin film having a color separation function. A large-sized rotating color filter disk with a driving motor is not required, and the size of the apparatus can be reduced.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing an example of a first color image display device according to the present invention.

FIG. 2 is a diagram schematically showing a configuration of an optical thin film shown in FIG.

FIG. 3 is a block diagram showing a mirror control unit of the first color image display device shown in FIG.

FIG. 4 is a diagram for explaining an example of control by a mirror control unit shown in FIG. 3;

FIG. 5 is a diagram schematically showing an overall configuration of a second color image display device according to the present invention.

6 is a diagram schematically showing a configuration of a mirror with a thin film of the deformable mirror device shown in FIG. 5;

FIG. 7 is a diagram for explaining an example of control by the mirror control unit shown in FIG.

FIG. 8 is a diagram showing a configuration of a color image display device as Conventional Technique 1.

FIG. 9 is a diagram for explaining a schematic configuration of a color image display device as Conventional Technique 2.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 11 ... Deformable mirror device (DMD) 12 ... Mirror 13 ... Parallel white light source 14 ... Optical thin film 15 ... Imaging lens 16 ... Screen 17 ... Image display means 18
... Signal separation circuit 19 ... Mirror tilt operation control circuit 20
... mirror control means 31 ... deformable mirror device (D
MD) 32: mirror with thin film 33: parallel white light source
34: imaging lens 35: screen 36: image display means 37: mirror control means

Claims (2)

[Claims] 1. A color image based on an image signal using a deformable mirror device having a plurality of mirrors that can be tilted to selectively reflect incident light according to an image signal. A color image display device for displaying color light, which irradiates each mirror of the deformable mirror device with incident light having a plurality of wavelength components including wavelength components of three primary colors giving at least three stimulus values of a color. Irradiating means, an optical thin film disposed at a predetermined position with respect to the deformable mirror device to generate transmitted light of a specific wavelength corresponding to an incident angle, and for each mirror of the deformable mirror device, On the basis of addressing the mirror at the position corresponding to the display image pattern, the optical thin film,
Mirror control means for controlling a tilt angle and a tilt holding time of the addressed mirror so that the incident light is sequentially incident at a specific incident angle according to a display color for each predetermined time after mirror reflection; and Image display means for forming an image of transmitted light from the optical thin film, at which the light reflected by the designated mirror is incident at the specific incident angle, and displaying a color image thereof. Color image display device. 2. A color image based on the image signal using a deformable mirror device having a plurality of mirrors that can be tilted to selectively reflect incident light according to an image signal. In the color image display device that displays, the deformable mirror device, as each mirror thereof,
A mirror with a thin film formed on the surface of the mirror body to generate a reflected light of a specific wavelength corresponding to the incident angle, wherein each thin film mirror of the deformable mirror device has at least a color Light irradiating means for color expression for irradiating incident light having a plurality of wavelength components including wavelength components of three primary colors giving tristimulus values, and mirrors with thin films of the deformable mirror device, based on the image signal Addressing the mirror with the thin film at a position corresponding to the display image pattern, and in order to make the incident light incident on the specified mirror with the thin film at a specific incident angle in accordance with the display color for each predetermined time sequentially, Mirror control means for controlling a tilt angle and a tilt holding time of the addressed mirror with a thin film; The light imaged, the color image display apparatus characterized by comprising an imaging display means for displaying the color image.