JPH11194313A - Projector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To display a high brightness color image at a low cost without requiring a high speed operation for display elements in a projector of a rotating filter or a moving filter type. SOLUTION: In a rotating filter liquid crystal projector 10, it is made possible to display a bright projected image by increasing the transmitting quantity of light made incident from a light source in comparison with an RGB (red.green.blue) filter plate and by making a filter plate 12 to be the MYC (magenta-yellow-cyan) type. Moreover, a display speed is decreased by displaying by means of interlaced scanning so that a low speed operating liquid crystal display 14 can be used and thus, the cost is reduced by simplifying the composition of a display control circuit.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a projector for projecting and displaying a color image using a display element.

[0002]

2. Description of the Related Art As a projector for projecting and displaying a color image using a conventional liquid crystal panel, for example, RGB projectors are known.
There is a three-panel liquid crystal projector configured with three liquid crystal panels each. In this three-panel projector, light projected from a lamp, which is a light source, is selectively transmitted / reflected by a dichroic mirror for each wavelength of light, and divided into three primary colors of RGB (red, green, and blue). Each of the divided lights is incident on three liquid crystal panels for each color to form an image for each color. Each image for each color is subjected to RG by a prism.
After B is superimposed, it is incident on the projection lens and is imaged on the screen.

Further, in the case of a single-panel type liquid crystal projector using one liquid crystal panel, the liquid crystal panel does not have a complicated structure as in the above-mentioned three-panel type projector. The RGB color filters are sequentially attached to the pixels arranged in a row, white light is incident from a lamp as a light source, and an image is formed on a screen by a projection lens.

[0004]

However, the conventional three-panel liquid crystal projector has the following problems.

[0005] 1. Since three expensive liquid crystal panels are used, the price of the device increases.

[0006] 2. Since the structure is complicated, miniaturization is difficult.

[0007] 3. The position of the image projected from the three liquid crystals must be strictly adjusted, and assembling accuracy is required at the time of manufacture, which increases the price of equipment. For this reason,
It cannot be applied to portable devices and the like to which vibration is applied.

The single-panel type liquid crystal projector has the following problems.

1. The use efficiency of light projected from the light source is low because the color filter is used. That is, the contrast of the image projected on the screen is lower than that of a CRT projector.

[0010] 2. Since the three primary colors are constituted by the three pixels on the liquid crystal panel, the actual resolution of the image formed on the screen is reduced to 1/3.

As a liquid crystal projector for solving the problems of the conventional three-panel and single-panel liquid crystal projectors, for example, RGB between a light source 1 and an LCD (Liquid Crystal Display) 3 as shown in FIG. The filter plate 2 which is color-coded is provided, and the filter plate 2 is rotated in accordance with the image scanning timing for driving the LCD 3 so that the RGB colored light enters the LCD 3 by the filter plate 2 which rotates the projection light from the light source 1. Let me
A filter-rotating liquid crystal projector that projects a color image formed on the LCD 3 from the projection lens 4 onto a screen (not shown) in accordance with the timing of incidence of the colored light has also been proposed.

However, in this conventional filter rotation type liquid crystal projector, for example, NTSC (National T
elevision System Committee), the image for one field is scanned at 60 Hz.
The colored light from the filter plate 2 divided into three colors of GB is converted into LC
In order to display an image for one field by the shutter operation of D3, it is necessary to rotate the filter plate 2 at a speed of three times or more of the scanning frequency, that is, at a speed of 180 Hz or more. Also needs to be operated in accordance with the rotation speed, and its L
A display element such as a CD3 is required to operate at a high speed, causing a problem of increasing the cost of the device.

In this conventional filter-rotating projector, when displaying, for example, an NTSC video signal, a one-frame image composed of an odd field and an even field is subjected to non-interlace scanning (sequential scanning). However, there is a problem that a display element that can operate at a higher speed is required to increase the cost, and a display image flickers.

An object of the present invention is to make it possible to display a high-luminance color image at low cost without requiring a high-speed operation of a display element in such a filter rotation type (or filter movement type) projector. is there.

[0015]

According to the first aspect of the present invention,
The light emitted from the light source is transmitted through a color-divided rotary color filter to selectively disperse the light, and the spectrum transmitted through the rotary filter is made incident on a display element, and the color input according to the spectral color In a projector that selects an image signal by a display control circuit to drive a display element to form a color display image, and enlarges and projects this color display image by a projection lens, the rotary color filter includes magenta (M) yellow The display control circuit divides the color into three colors of (Y) and cyan (C), and determines each spectral color selected from the rotation position of the rotary color filter, and corresponds to each of the determined spectral colors. A color display image is formed by selecting the input color image signal and driving the display element interlacedly.

According to the first aspect of the present invention, the light emitted from the light source is transmitted through the color-divided rotary color filter to selectively split the light, and the spectrum transmitted through the rotary filter is displayed on the display element. The display control circuit selects a color image signal input according to the spectral color, drives a display element to form a color display image, and enlarges and projects the color display image by a projection lens. , The rotary color filter is a magenta (M)
-The color is divided into three colors of yellow (Y) and cyan (C), and the display control circuit discriminates each spectral color selected from the rotation position of the rotary color filter, and assigns each of the determined spectral colors. The corresponding input color image signal is selected, and the display elements are interlaced to form a color display image.

Therefore, the amount of transmission of the incident light from the light source is larger than that of a color filter which is divided into three primary colors, RGB, so that a bright projected image can be displayed. In addition, to display by interlaced scanning,
The display speed can be reduced, and a display element which is a display device, which operates at a low speed, can be used, so that the configuration of the display control circuit can be simplified and the cost can be reduced.

According to a second aspect of the present invention, the light emitted from the light source is transmitted through a color-divided rotary color filter to selectively split the light, and the spectrum transmitted through the rotary filter is incident on a display element. A display control circuit that selects a color image signal input according to the spectral color, drives a display element to form a color display image, and enlarges and projects the color display image using a projection lens. The control circuit further includes an image memory that stores the input color image signal for each color, stores the input color image signal in the image memory for each color, and selects each of the rotation color filters selected from the rotation position. Spectral colors are determined, a color image signal corresponding to the determined spectral colors is read from an image memory, and the display elements are interlaced to form a color display image. It is characterized in.

According to the second aspect of the present invention, the light emitted from the light source is transmitted through the color-divided rotary color filter to selectively split the light, and the spectrum transmitted through the rotary filter is displayed on the display element. A liquid crystal projector that selects a color image signal input according to the spectral color by a display control circuit, drives a display element to form a color display image, and enlarges and projects the color display image by a projection lens. , The display control circuit further comprises an image memory for storing the input color image signal for each color, storing the input color image signal for each color in the image memory, from the rotation position of the rotary color filter Each of the selected spectral colors is determined, a color image signal corresponding to the determined spectral color is read out from the image memory, and the display element is driven in an interlaced manner to display a color display image. To form.

Therefore, the timing of writing to the image memory does not need to be synchronized with the timing of driving the display element, and an image can be projected without being affected by the scanning frequency of the input color image signal.

According to a fifth aspect of the present invention, light emitted from a light source is transmitted through a color-divided moving color filter to selectively separate the light, and the light transmitted through the moving filter is incident on a display element. A display control circuit that selects a color image signal input according to the spectral color, drives a display element to form a color display image, and enlarges and projects the color display image using a projection lens. The control circuit detects the boundary of the color when the movable color filter moves, determines the irradiation period of each selected spectral color, and synchronizes with the determined irradiation period of each spectral color,
It is characterized in that the input color image signal corresponding to each spectral color is selected and the display element is driven to form a color display image.

According to the fifth aspect of the present invention, the light emitted from the light source is transmitted through the color-divided movable color filter to selectively disperse the light, and the spectrum transmitted through the movable filter is displayed on the display element. The display control circuit selects a color image signal input according to the spectral color, drives a display element to form a color display image, and enlarges and projects the color display image by a projection lens. The display control circuit detects a color boundary when the color filter is moved, determines an irradiation period of each selected spectral color, and synchronizes with each of the determined irradiation periods of each spectral color. The input color image signal corresponding to the spectral color is selected, and the display element is driven to form a color display image.

Therefore, it is possible to control the display period of the color image displayed on the display element in accordance with the color boundary at the time when the movable color filter moves, and it corresponds to the color transition timing of the movable color filter. The display timing of the color image can be matched, and the reproducibility of the color of the projected image can be improved.

According to a seventh aspect of the present invention, the light emitted from the light source is transmitted through a color-divided moving color filter to selectively split the light, and the light transmitted through the moving filter is incident on a display element. The display control circuit selects a color image signal input according to the spectral color, drives a display element to form a color display image, and enlarges and projects the color display image by a projection lens. The color filter sets the ratio of each color according to the spectral distribution of the light source, and the display control circuit detects the boundary of the color when the movable color filter moves, and selects each spectral color to be selected. The input color image signal corresponding to each spectral color is selected and the display element is driven in synchronization with the determined irradiation period of each spectral color to form a color display image. It is characterized in Rukoto.

According to the seventh aspect of the present invention, the light emitted from the light source is transmitted through the color-divided movable color filter to selectively split the light, and the spectrum transmitted through the movable filter is displayed on the display element. The display control circuit selects a color image signal input according to the spectral color, drives a display element to form a color display image, and enlarges and projects the color display image by a projection lens. The movable color filter sets the ratio of each color in accordance with the spectral distribution of the light source, and the display control circuit detects and selects a color boundary when the movable color filter moves. The irradiation period of each spectral color is determined, and the input color image signal corresponding to each spectral color is selected and the display element is driven in synchronization with the determined irradiation period of each spectral color to drive the color display image. To form.

Therefore, it is possible to change the color division ratio of the movable color filter so as to correct the spectral distribution of the light source, and control the display period of the color image displayed on the display element in accordance with the color division ratio. In addition, the spectral distribution of the light source can be canceled by the color area ratio of the color filter, and an image with improved color balance can be projected. Further, since the color balance can be corrected only by the color filters, an inexpensive light source can be used, and the cost of the projector can be reduced.

[0027]

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

(First Embodiment) FIGS. 1 to 4 show a filter-rotating liquid crystal projector 10 according to a first embodiment of the present invention.

First, the configuration will be described.

FIG. 1 is a diagram showing a main configuration inside a liquid crystal projector 10 according to the first embodiment. In FIG. 1, a liquid crystal projector 10 includes a light source lamp 11, a filter plate 12, a condenser lens 13, an LCD
14 and a projection lens 15. FIG.
, The light projected from the lamp 11
The light is incident on a filter plate 12 that is driven to rotate in synchronization with an image scanning timing by the filter 6, and is separated into three colors by the filter plate 12 that is divided into three colors. Incident on the LCD 14. The LCD 14 is driven and controlled by a display control circuit 28 and a liquid crystal driver 27, which will be described later, in accordance with the scanning timing of the input image. An image is formed, and a color image is formed and displayed on a screen (not shown) by the projection lens 15.

The filter plate 12 has a MYC
It is formed of a disk-shaped transmissive plate colored in three colors (magenta, yellow, and cyan), and the central portion thereof is connected to the rotating mechanism 16 and driven to rotate. The rotation speed is set in accordance with the scanning timing of the image signal input to the LCD 14. For example, when the image signal input to the LCD 14 is a video signal based on NTSC, the video signal for one field is scanned.
In order to form an image for one field with each color of RGB in synchronization with the scanning timing of Hz, the image is rotated at a speed of 180 Hz which is three times 60 Hz.

Also, in the filter plate 12, every time one rotation, the incident light from the lamp 11 is divided into magenta (M) → yellow (Y) → cyan (C) in the order of three colors. It is assumed that the light is incident on the condenser lens 13.

A circuit configuration of a control system in the liquid crystal projector 10 will be described with reference to a block diagram shown in FIG. In FIG. 2, the same components as those shown in FIG. 1 are denoted by the same reference numerals. In FIG.
The control system of the liquid crystal projector 10 includes a motor control circuit 16a, a motor 16b, an image data interface 21, image memories 22 to 24, which are the rotation mechanism 16 in FIG.
It comprises a memory control circuit 25, a D / A converter 26, a liquid crystal driver 27, a display control circuit 28, a display timing control circuit 29, a rotary encoder 30, a CPU 31, a program ROM 32, and a storage medium interface 33.

The motor control circuit 16a controls the rotation speed of the motor 16b in accordance with the scanning timing of the image signal input to the LCD 14 based on the basic clock timing input from a control unit (not shown).
The filter plate 12 is rotated by 6b.

The image data interface 21 has an image input terminal 21a for connecting to an image input device (not shown) such as a video camera or a digital camera (not shown), and an external image input device is connected via the image input terminal 21a. The color image data input from C is converted to Y (luminance) data and C
(Color) data, and further separates the separated color data into RGB color data, and converts these color data RGB into image memories 2 corresponding to RGB.
A memory write signal for writing to 2 to 24 is output to the memory control circuit 25, and in accordance with the write control signal output from the memory control circuit 25 to each of the image memories 22 to 24,
The separated color data RGB is output to each of the image memories 22 to 24 corresponding to RGB, and the color data RGB for one screen is stored.

The image memory 22 is for storing red color data R, the image memory 23 is for storing green color data G, and the image memory 24 is for storing blue color data B. Memory for Each of the image memories 22 to 24 has a memory area for storing each color data of one screen, and writing / reading of each color data RGB is controlled by the memory control circuit 25.

The memory control circuit 25 outputs a memory write control signal to each of the image memories 22 to 24 in response to a memory write signal input from the image data interface 21, and the image data interface 21 To 24, respectively, to control the writing of each color data RGB output to the display control circuit 2.
8 outputs a memory read control signal to each of the image memories 22 to 24 in response to the memory read signal input from the memory 8, and outputs the color data RG stored in each of the image memories 22 to 24.
B are sequentially read and output to the D / A converter 26 sequentially.

The D / A converter 26 includes a display control circuit 2
Each of the color data RGB sequentially read out from each of the image memories 22 to 24 in synchronism with the clock timing of the clock signal input from the D.A.
The data is converted and sequentially output to the liquid crystal driver 27 as an analog image signal for each of RGB.

The liquid crystal driver 27 is a D / A converter 2
The display control circuit 28 generates an image signal to be applied to each liquid crystal element in the LCD 14 based on each of the RGB analog image signals sequentially input from the LCD 6, and synchronizes with the scanning timing of the scanning timing signal input to the LCD 14 by the display control circuit 28. The image signal is output to the LCD 14.

The display control circuit 28 outputs a memory read signal for reading each color data RGB from the image memories 22 to 24 to the memory control circuit 25 according to the color selection signal RGB input from the display timing control circuit 29. Then, a clock signal for controlling the D / A conversion timing is output to the D / A converter 26 in accordance with the display start signal input from the display timing control circuit 29, and a clock signal for controlling the scanning timing is output to the LCD 14. .

The display timing control circuit 29 is a color signal for selecting image memories 22 to 24 from which each color data RGB is read, based on an encode signal 2 input from a rotary encoder 30 for detecting a rotation angle of the filter plate 12. A selection signal RGB is output to the display control circuit 28, and a display start signal indicating a D / A conversion start timing and a scan start timing is sent to the display control circuit 28 based on the encode signal 1 input from the rotary encoder 30. Output.

The display timing control circuit 29 sets the output pattern of the memory selection signal RGB each time the encode signal 1 is input from the rotary encoder 30. That is, every time the encode signal 1 is output, the filter plate 12 separates the lamp 1 in the order of magenta (M) → yellow (Y) → cyan (C) in three colors.
Since the incident light from 1 is split, the display timing control circuit 29 sets the selection condition of the image data RGB read from the image memories 22 to 24 according to the changing order of the split. Hereinafter, this display timing control circuit 2
9, the selection conditions of the image data RGB are
This is shown in relation to the scanning lines on the LCD 14. In addition, since the display of the LCD 14 alternately displays the odd lines and the even lines, R, G, and B are displayed in the order of FIG.

That is, the filter plate 12 selects magenta (M) → the R image on the odd and even lines of the LCD 14 The filter plate 12 selects yellow (Y) → the G image on the odd / even lines of the LCD 14 The cyan (C) ) → B image is selected on odd and even lines of LCD 14.

The rotary encoder 30 detects the rotation angle of the filter plate 12 and outputs the encode signals 1 and 2 to the display timing control circuit 29. The rotary encoder 30 outputs an encode signal 1 every time the filter plate 12 detects that the filter plate 12 has rotated 360 °,
Each time it is detected that 2 has been rotated by 120 °, which is one divided color, an encode signal 2 is output. Therefore, the rotary encoder 30 outputs the encode signal 1 every time the filter plate 12 divided into three colors rotates 120 ° in the order of magenta (M) → yellow (Y) → cyan (C). And

CPU (Central Processing Unit) 31
Executes a process of controlling a display control operation in each control block in the liquid crystal projector 10 based on a control program stored in the program ROM 32. A program ROM (Read Only Memory) 32 stores a control program for a control process executed by the CPU 31.

The storage medium interface 33 is connected to a storage medium 34 in which programs, data, and the like are stored in advance, and the storage medium 34 is constituted by a magnetic or optical recording medium or a semiconductor memory. The storage medium 34 is fixedly provided on the storage medium interface 33 or is detachably mounted.
The storage medium 34 stores data processed by the control program and the like.

The program, data, and the like stored in the storage medium 34 may be configured to be received and stored from another device connected via a communication line or the like. A storage device having the storage medium may be provided on the other connected device side, and the program and data stored in the storage medium 7 may be used via a communication line.

Next, the operation of the first embodiment will be described.

The operation of the control system in the liquid crystal projector 10 shown in FIG. 2 will be described with reference to the timing chart shown in FIG. In the first embodiment, as shown in FIG. 4, an odd line (interlaced scanning) is displayed every other line in the horizontal direction from the upper left to the lower right of the display screen of the LCD 14 using a display method called interlaced scanning. A display operation of scanning one screen of input image data in field units for each of the even lines (broken lines in the figure) and the even lines (dashed lines in the figure) is performed, and input to the image interface 21 from an external image input device. Image data to be
The case of displaying on the CD 14 will be described.

In FIG. 3, (a) shows the filter plate 1
2 shows a change in the color of the incident light split by the encoder 2. FIG. 2B shows an encode signal 1 output from the rotary encoder 30, and FIG. 2C shows an encode signal output from the rotary encoder 30. 2D shows the output timing of the memory selection signal R output from the display timing control circuit 29, and FIG. 2E shows the memory selection signal G output from the display timing control circuit 29. (F) of FIG.
Shows the output timing of the memory selection signal B output from the display timing control circuit 29, and FIG.
FIG. 4 shows a change in color of an image signal output to an odd line of the CD 14, and FIG. 6H shows a change in color of an image signal output to an even line of the LCD 14.

First, in FIG. 2, the motor control circuit 16
a controls the rotation speed of the motor 16b in accordance with the scanning timing of the image signal input to the LCD 14 based on the basic clock timing input from a control unit (not shown), and rotates the filter plate 12 by the motor 16b. . By this rotation control, the filter plate 12
As shown in FIG. 3A, each time one rotation is made (T1 to T3 in FIG. 3).
During the period T4 to T6), the incident light from the lamp 11 is divided into magenta (M) → yellow (Y) → cyan (C) in the order of the three colors, and the condensing lens 13
Incident on

The rotation angle of the filter plate 12 is detected by the rotary encoder 30. Every time the filter plate 12 is rotated by 120 °, which is one color, the rotation angle of FIG.
(C) is output to the display timing control circuit 29, and every time it detects that the filter plate 12 has rotated 360 °, the encode signal 2 shown in FIG.
Is output to the display timing control circuit 29.

In the image data interface 21, Y (luminance) data and C (color) data are separated from image data input from an external image input device connected to the image input terminal 21a. The color data is further separated into RGB color data. In the image data interface 21, a memory write signal for writing each of the color data RGB into each of the image memories 22 to 24 corresponding to RGB is output to the memory control circuit 25. In accordance with the write control signals output to the memories 22 to 24, the separated color data RGB are output to the image memories 22 to 24 corresponding to RGB, and the color data RGB for one screen is stored. .

The operation timing of writing each color data into the image memories 22 to 24 by the image data interface 21 may be asynchronous with the operation timing of each unit shown in FIG. Is set to a level that does not cause

On the other hand, in the display timing control circuit 29,
When the encode signal 1 is input from the rotary encoder 30 at a timing before the period T1 shown in FIG. 3 starts, a display start signal indicating a D / A conversion start timing and a scan start timing is output to the display control circuit 28. You. In the display control circuit 28, the display timing control circuit 2
When a display start signal is input from 9, a clock signal for controlling D / A conversion timing is output to the D / A converter 26, and a clock signal for controlling scanning timing is output to the LCD 14.

After outputting the display start signal in the display timing control circuit 29, since the position of the filter color with respect to the condenser lens 13 of the filter plate 12 is magenta M in the period T1 shown in FIG. Data RG
As shown in the selection condition of B, the filter plate 12 selects the R image with magenta (M) → odd line of the LCD 14 (T
At 1 but at T4 it is an even line. 3), the color selection signal R (active “Hi” level) is output to the display control circuit 28 in the pattern shown in FIG. In the display control circuit 28, the display timing control circuit 2
The memory read signal R is output to the memory control circuit 25 in accordance with the color selection signal R input from 9. In the memory control circuit 25, an operation of reading out the color data R from the image memory 22 that stores the color data R is performed according to the memory readout signal R input from the display control circuit 28, and the read out color data R Output to the D / A converter 26.

In the D / A converter 26, the color data R read from the image memory 22 is D / A (digital / analog) converted in synchronization with the clock timing of the clock signal input from the display control circuit 28. Then, it is output to the liquid crystal driver 27 as an analog image signal R. In the liquid crystal driver 27, an image signal R to be applied to the liquid crystal element of each line in the LCD 14 is generated based on the analog image signal R input from the D / A converter 26, and the scanning input to the LCD 14 by the display control circuit 28. The image signal R is output to the LCD 14 in synchronization with the scanning timing of the timing signal, and an image of the R (red) component is displayed on the screen of the LCD 14. At this time, the filter plate 12 responds to the incident light emitted from the light source lamp 11.
3 is the position of magenta M, and the color component of magenta M is R + B.
, The color ratio of the display image formed on the odd lines of the screen of the LCD 14 is R: G: B = 1: 0: 1.

Next, the filter plate 12 is further rotated, and the boundary between magenta M and yellow Y before the transition to the period T2 in FIG. 3 is detected by the rotary encoder 30 and the encode signal 2 is sent to the display timing control circuit 29. When output, the display timing control circuit 29 outputs the period T
2 and the color for the incident light of the filter plate 12 shifts to yellow Y, so that the filter plate 12 changes from yellow (Y) to G in the even line of the LCD 14 as shown in the selection condition of the image data RGB. To select an image, a color selection signal G (active “Hi” level) is output to the display control circuit 28 in the pattern shown in FIG. In the display control circuit 28, the display timing control circuit 2
The memory read signal G is output to the memory control circuit 25 in response to the color selection signal G input from 9. In the memory control circuit 25, an operation of reading the color data G from the image memory 23 that stores the color data G is performed according to the memory read signal G input from the display control circuit 28, and the read color data G is Output to the D / A converter 26.

In the D / A converter 26, the color data G read from the image memory 22 is D / A (digital / analog) converted in synchronization with the clock timing of the clock signal input from the display control circuit 28. Then, it is output to the liquid crystal driver 27 as an analog image signal G. In the liquid crystal driver 27, an image signal G to be applied to the liquid crystal elements of each line in the LCD 14 is generated based on the analog image signal G input from the D / A converter 26, and the scanning input to the LCD 14 by the display control circuit 28. The image signal is output to the LCD 14 in synchronization with the scanning timing of the timing signal, and the image of the G (green) component is displayed on the screen of the LCD 14. At this time, since the rotation angle of the filter plate 12 is at the position of yellow Y with respect to the incident light emitted from the light source lamp 11, the yellow Y
Is R + G, the color ratio of the display image formed on the even lines of the screen of the LCD 14 during the period T2 shown in FIG. : G: B = 1: 1: 1: 0.

When the filter plate 12 is further rotated, FIG.
When the rotary encoder 30 detects the boundary between the yellow Y and the cyan C before the transition to the period T3, the encoded signal 2 is output to the display timing control circuit 29, and the display timing control circuit 29 proceeds to the period T3. Then, the color of the filter plate 12 with respect to the incident light shifts to cyan C, so that the filter plate 12 becomes cyan (C) → LCD as shown in the selection condition of the image data RGB.
As shown in FIG. 3, the B image is selected by the 14 odd lines.
In the pattern shown in FIG.
i ”level) is output to the display control circuit 28. In the display control circuit 28, a memory read signal B is output to the memory control circuit 25 according to the color selection signal B input from the display timing control circuit 29. In the memory control circuit 25, the memory read signal B input from the display control circuit 28
The operation of reading out the color data B from the image memory 24 that stores the color data B is performed according to the above, and the read out color data B is output to the D / A converter 26.

In the D / A converter 26, the color data B read from the image memory 22 is D / A (digital / analog) converted in synchronization with the clock timing of the clock signal input from the display control circuit 28. Then, it is output to the liquid crystal driver 27 as an analog image signal B. In the liquid crystal driver 27, an image signal B to be applied to the liquid crystal elements of each line in the LCD 14 is generated based on the analog image signal B input from the D / A converter 26, and the scanning input to the LCD 14 by the display control circuit 28. The image signal B is output to the LCD 14 in synchronization with the scanning timing of the timing signal, and an image of the B (blue) component is displayed on the screen of the LCD 14. At this time, the filter plate 12 responds to the incident light emitted from the light source lamp 11.
Is the position of cyan C, and since the color component of cyan C is B + G, the rotation angle of the image of the LCD 14 during the period T3 shown in FIG. The color ratio of the display image formed on the odd-numbered line is R: G: B = 0: 1: 1.

As described above, in the period T1, a display image having a color ratio of R: G: B = 1: 0: 1 is projected on an odd line, and in a period T2, a color ratio of R: G: B = on an even line.
A display image of 1: 1: 0 is projected, and in the period T3, a display image with a color ratio of R: G: B = 0: 1: 1 is projected on odd lines.

Then, after the filter plate 12 rotates in the order of magenta M → yellow Y → cyan C, one rotation (360 °)
When the rotation is detected by the rotary encoder 30, the encode signal 1 shown in FIG. 3B is output to the display timing control circuit 29. Then, similarly to the above, the image memories 22 to 22 through the image data interface 21 are used.
The writing operation of each color data RGB into the pixel 24 is performed, and every time the period shifts from the period T4 to T6 shown in FIG.
When rotated in the order of yellow Y → cyan C, the rotation angle is similarly detected by the rotary encoder 30, and the encode signal 2 is output to the display timing control circuit 29.

In a period T4 in FIG. 3, the display timing control circuit 29 outputs a color selection signal R (active "Hi" level) to the display control circuit 28 in the pattern shown in FIG. The display control circuit 28 outputs a memory read signal R to the memory control circuit 25 in accordance with the input color selection signal R, and the memory control circuit 25 stores the color data R in accordance with the input memory read signal R. The read operation of the color data R to the image memory 22 is performed, and the read color data R is output to the D / A converter 26.

The color data R read from the image memory 22 is D / A (digital / analog) converted by the D / A converter 26 in synchronization with the clock timing of the clock signal input from the display control circuit 28. , Is output to the liquid crystal driver 27 as an analog image signal R. In the liquid crystal driver 27, an image signal R to be applied to the liquid crystal element of each line in the LCD 14 is generated based on the analog image signal R input from the D / A converter 26, and the scanning input to the LCD 14 by the display control circuit 28. The image signal R is output to the LCD 14 in synchronization with the scanning timing of the timing signal, and an image of the R (red) component is displayed on the screen of the LCD 14. At this time, the filter plate 12 responds to the incident light emitted from the light source lamp 11.
Is the position of magenta M, and the color component of the magenta M is R + B. Therefore, the rotation angle is the same as the color component of the image signal R applied to the LCD 14 during the period T4 shown in FIG.
, The color ratio of the display image formed on the even lines of the screen of the LCD 14 is R: G: B = 1: 0: 1.

Similarly, in the period T5 in FIG.
, A color selection signal G is output from the display timing control circuit 29 to the display control circuit 28, and the color data G is read from the image memory 23 and output to the D / A converter 26. A converter 2
The signal is converted into an analog image signal G by 6 and output to the liquid crystal driver 27. Then, an image signal G to be applied to the liquid crystal elements of each line in the LCD 14 is generated by the liquid crystal driver 27 based on the analog image signal G.
, The G (green) component image is displayed on the LCD
14 is displayed on the screen. At this time, since the rotation angle of the filter plate 12 is at the position of the yellow Y with respect to the incident light emitted from the light source lamp 11, the color component of the yellow Y is R + G. In the period T5 shown in FIG.
The color ratio of the display image formed on the odd lines of the screen of the LCD 14 is R: G: B = 1: 1: 0.

Similarly, during period T6 in FIG. 3, (f) in FIG.
The color selection signal B is output from the display timing control circuit 29 to the display control circuit 28 in accordance with the memory selection signal B shown in (1), and the color data B is read out from the image memory 23 and output to the D / A converter 26. A converter 2
The signal is converted into an analog image signal B by 6 and output to the liquid crystal driver 27. Then, an image signal B to be applied to each liquid crystal element in the LCD 14 is generated by the liquid crystal driver 27 based on the analog image signal B and applied to the LCD 14, whereby an image of the B (blue) component is displayed on the screen of the LCD 14. Is done. At this time, the rotation angle of the filter plate 12 with respect to the incident light emitted from the light source lamp 11 is cyan C
, The color component of cyan C is B + G, so that it is formed on the even lines of the screen of the LCD 14 in the period T6 shown in FIG. The color ratio of the displayed image
R: G: B = 0: 1: 1.

As described above, in the period T4, a display image having a color ratio of R: G: B = 1: 0: 1 is projected on even-numbered lines, and in the period T5, a color ratio of R: G: B = on an odd-numbered line.
A display image of 1: 1: 0 is projected, and in the period T6, a display image with a color ratio of R: G: B = 0: 1: 1 is projected on even-numbered lines.

As described above, the input image data for each field is sequentially selected from the color memories RGB read out from the image memories 22 to 24 in accordance with the rotational position of the filter plate 12, whereby the LCD 14 screen is displayed. Of the color image R in the order shown in FIG.
GB are formed by interlaced scanning, and color images RGB are formed by interlaced scanning on even-numbered lines in the order shown in FIG.

The liquid crystal projector 1 according to the first embodiment
At 0, a display image is formed by interlaced scanning for both odd and even lines, so that the period T1 + T2,
A color image of a pair of periods T3 + T4 and T5 + T6 is used as a color image for projection, and the color ratio of the image projected together with the color position of the filter plate 12 in each pair period is as follows.

In the period T1 + T2, the filter plate 12
(R + B) + Y (R + G), the display image is an odd line R
+ R and even lines B + G, so that 2R +
1G + 1B, and the color ratio is R: G: B = 2:
1: 1.

In the period T3 + T4, the filter plate 12
(B + G) + M (R + B), display image is odd line B
+ B and even lines G + R, so that a total of 1R +
1G + 2B, and the color ratio is R: G: B = 1:
1: 2.

In the period T5 + T6, the filter plate 12
(R + G) + C (B + G), the display image is an odd line G
+ G, even line R + B, so that 1R +
2G + 1B, and the color ratio is R: G: B = 1:
2: 1.

Therefore, when the relationship between the actually displayed color and the display period is calculated based on the color ratio of the projected image, the actual display color ratio and the division of the filter plate 12 in the first embodiment are calculated. The relationship with the color ratio of the projected image when the color is MYC is as follows.

Display white (R: G: B = 1: 1: 1) → Projected image R: G: B = 1: 1: 1 Display pure red (R: G: B = 1: 0: 0) → Projected image R: G: B = 2: 1: 1 Display pure green (R: G: B = 0: 1: 0) → Projected image R: G: B = 1: 2: 1 Display pure blue ( R: G: B = 0: 0: 1) → Projected image R: G: B = 1: 1: 2 Magenta is displayed (R: G: B = 1: 0: 1) → Projected image R: G: B = 3: 2: 3 Yellow is displayed (R: G: B = 1: 1: 0) → Projected image R: G: B = 3: 3: 2 Cyan is displayed (R: G: B = 0: 1: 1) → Projected image R: G: B = 2: 3: 3 As described above, in the liquid crystal projector 10 according to the first embodiment, pure red, pure green, pure blue, magenta, and yellow other than white display are used. For each color display of cyan and cyan, white is added. Therefore, the brightness of the projected image is improved and the same color is displayed.
In addition, the MYC filter plate 12 has two colors of each of the three primary colors of RGB each of MYC compared to a conventional RGB filter plate. Double brightness can be obtained.

Therefore, in the filter rotation type liquid crystal projector 10 according to the first embodiment, since the filter plate 12 is of the MYC type, the amount of transmission of incident light incident from the light source is larger than that of the RGB type filter plate. , A bright projected image can be displayed. Further, since the display is performed by interlaced scanning, the display speed can be reduced, the LCD 14 serving as the display device can be operated at a low speed, and the configuration of the display control circuit can be simplified and the cost can be reduced.

In the filter rotating type liquid crystal projector 10 according to the first embodiment, a case where a transmissive LCD is used as the LCD 14 has been described.
D may be used, or another display device using a filter plate may be used.

(Second Embodiment) In the first embodiment, the portion connected to an external image input device is shown as the image data interface 21 in FIG.
In the second embodiment, a case will be described in which a television signal such as NTSC can be input.

FIG. 5 is a diagram showing a circuit configuration of an image data interface 40 according to the second embodiment. Other circuit configurations of the liquid crystal projector are the same as those shown in FIG.
Since the configuration is the same as that of the filter rotating type liquid crystal projector 10 shown in FIG.

In FIG. 5, the image data interface 40 includes a Y / C separation circuit 41, an RGB decode circuit 4
2. Clock generation circuit 43 and A / D converter 44
To 46.

The Y / C separation circuit 41 separates a luminance signal Y, a chrominance signal C, and a synchronizing signal from a television signal input from an input terminal 40a connected to an external video deck or the like via a cable. The signal Y and the color signal C are output to the RGB decoding circuit 42, and the synchronization signal is output to the clock generation circuit 4
Output to 3.

The RGB decoding circuit 42 decodes an analog RGB signal from the luminance signal Y and the chrominance signal C input from the Y / C separation circuit 41, outputs an analog R signal to the A / D converter 44, and outputs an analog G signal. Is output to the A / D converter 45, and the analog B signal is output to the A / D converter 46.

The clock generation circuit 43 generates a clock signal for controlling the A / D conversion operation timing in the A / D converters 44 to 46 based on the synchronization timing of the synchronization signal input from the Y / C separation circuit 41. A /
The memory control circuit shown in FIG. 2 outputs to the D converters 44 to 46 and generates a memory write signal for controlling the write timing of the image data RGB in the image memories 22 to 24 shown in FIG. 25.

A / D converters 44 to 46 receive analog RGB signals inputted from RGB decode circuit 42, respectively.
The signal is synchronized with the clock signal input from the clock generation circuit 43 to A / D (analog / digital)
The data RGB is converted to generate data RGB, and each of the data RGB is output to the image memories 22 to 24 in synchronization with a write timing according to a memory write signal output from the clock generation circuit 43 to the memory control circuit 25. RGB is written.

Next, the operation of the second embodiment will be described.

In the image data interface 40 of FIG. 2, when a television signal is input to the Y / C separation circuit 41 from an input terminal 40a connected to an external video deck or the like via a cable, a luminance signal is converted from the television signal. The Y signal, the color signal C, and the synchronization signal are separated, and the luminance signal Y and the color signal C are output to the RGB decoding circuit 42, and the synchronization signal is output to the clock generation circuit 43.

The RGB decode circuit 42 decodes an analog RGB signal from the luminance signal Y and the chrominance signal C input from the Y / C separation circuit 41, and converts the analog R signal to A / C signal.
The analog G signal output to the D converter 44 is A / D
The analog B signal is output to the A / D converter 46 while being output to the converter 45.

In the clock generation circuit 43, Y / C
Based on the synchronization timing of the synchronization signal input from the separation circuit 41, the A / D converters 44 to 46
A clock signal for controlling the D conversion operation timing is generated and output to each of the A / D converters 44 to 46, and also controls the write timing of the image data RGB in the image memories 22 to 24 shown in FIG. Is generated and output to the memory control circuit 25 shown in FIG.

Then, in the A / D converters 44 to 46, the analog RGB signals input from the RGB decode circuit 42 are converted into A / D (analog / digital) signals in synchronization with the clock signals input from the clock generation circuit 43, respectively. The data RGB are converted to generate data RGB, and each of the data RGB is output to the image memories 22 to 24 in synchronization with a write timing according to a memory write signal output from the clock generation circuit 43 to the memory control circuit 25. Data RGB is written.

The image memories 22 to 24 and the memory control circuit 25 in the liquid crystal projector 10 shown in FIG.
The control operation by the D / A converter 26, the liquid crystal driver 27, the display control circuit 28, and the display timing control circuit 29 is the same as that of the first embodiment, and the description is omitted.

As described above, in the liquid crystal projector 10 according to the second embodiment, since a television signal input from the outside can be projected and displayed by the image data interface 40, a single-panel low-cost type capable of displaying a television image is provided. Type liquid crystal projector can be provided. Further, since the television image is projected in synchronization with the rotating filter plate 12, a clear image without flicker can be displayed even if the input signal frequency is low.

In the liquid crystal projector 10 according to the second embodiment, the image data interface 40
Are temporarily stored in the image memories 22 to 2
After the data is stored in the LCD 4, the liquid crystal display element in the LCD 14 is driven. Therefore, the timing of writing to the image memories 22 to 24 does not need to be synchronized with the timing of driving the liquid crystal display element. An image can be projected without being affected by frequency.

(Third Embodiment) In the first embodiment, a portion connected to an external image input device is shown as an image data interface 21 in FIG. 2, and in the second embodiment, an NTSC In the third embodiment, an image signal input from a data processing device such as an external personal computer via a communication line can be input. The configuration will be described.

FIG. 6 is a diagram showing a circuit configuration of a main part of a filter rotation type liquid crystal projector 50 according to the third embodiment. 6, the same components as those of the liquid crystal projector 10 shown in FIG. 2 are denoted by the same reference numerals, and the description thereof will be omitted. In addition, the circuit configuration of the other liquid crystal projector will be the same as that of the liquid crystal projector shown in FIG. Projector 10
Since the configuration is the same as that of FIG.

In FIG. 6, the liquid crystal projector 50 is
Image memories 22 to 24, memory control circuit 25, CPU3
1, a program ROM 32, a storage medium interface 33, a storage medium 34, a communication interface 51, and a buffer memory 52.
1. The program ROM 32, the storage medium interface 33, the communication interface 51, and the buffer memory 52 are connected to a data bus BD and an address bus AB. The image memories 22 to 24 are connected to a data bus DB, and the memory control circuit 25 is connected to an address bus AB.

The communication interface 51 is a USB (Universal Serial Interface) for connecting to a data processing device such as a personal computer (not shown) via a communication line.
al Bus), IEEE1394, or the like, and has a communication terminal 51a for data communication. The communication terminal 51a performs data communication processing with an external data processing device via the communication terminal 51a, and an image input from the data processing device. Data is transferred to data bus DB
Is transferred to and stored in the buffer memory 52.

When the image data is stored in a storage medium 34 such as a floppy disk, the image data is transmitted / received via a storage medium interface 33 so that the liquid crystal projector 50 of the third embodiment can be used. It can be carried independently of the data processing device.

The buffer memory 52 forms a memory area for temporarily storing image data transferred via the data bus DB by the communication interface 51.

The CPU 31 analyzes the image data stored in the buffer memory 52 based on the image forming processing program stored in the program ROM 32 to form RGB display color data, and synchronizes with the display timing. A write address instruction signal for designating a write destination address is output to the memory control circuit 25 via the address bus AB, and in accordance with the write control signal output from the memory control circuit 25 to each of the image memories 22 to 24, The color data RGB are output to the image memories 22 to 24 corresponding to RGB, and the color data RGB for one screen is stored.

The program ROM 32 stores an image forming processing program executed by the CPU 31 and the like.

Next, the operation of the third embodiment will be described.

In the liquid crystal projector 50 shown in FIG. 6, a data communication process is executed between the communication interface 51 and a data processing device such as an external personal computer connected to the communication terminal 51a via a communication line. When image data is transmitted from the device, the image data is received by the communication interface 51 and is stored in the buffer memory 52.
Is stored in

The image data stored in the buffer memory 52 is subjected to image forming processing by the CPU 31 based on the image forming processing program stored in the program ROM 32, whereby the data contents are analyzed and the RGB data is analyzed. Display color data is formed. When the CPU 31 outputs a write address instruction signal for designating a write destination address to the memory control circuit 25 via the address bus AB in synchronization with the display timing, the memory control circuit 25 sends the image memories 22 to 24 to each other. Of each color data RG in accordance with the write control signal
B is output to the image memories 22 to 24 corresponding to RGB, and the color data RGB for one screen is stored.

The liquid crystal projector 50 shown in FIG.
The control operations by the image memories 22 to 24, the memory control circuit 25, and the D / A converter 26, the liquid crystal driver 27, the display control circuit 28, and the display timing control circuit 29 which are the same components shown in FIG. Since the third embodiment is the same as the first embodiment, the description thereof is omitted.

As described above, in the liquid crystal projector 50 according to the third embodiment, the communication interface 5
1 allows image data input from an external data processing device to be projected and displayed.
The digital interface 1 can accurately project image data generated by a personal computer or the like without loss.

The communication interface 51 eliminates the need to carry a device such as a personal computer as an image data source together with the liquid crystal projector 50, so that the portability of the liquid crystal projector 50 can be improved.

Therefore, by using the communication interface 51, a filter rotating type liquid crystal projector 50 that can be directly connected to information equipment can be configured. In addition, by connecting the communication interface to a portable terminal having a built-in communication function, it is possible to configure a filter-rotating liquid crystal projector 50 that downloads and uses image data from a remotely located information device at the time of projection. .

Further, by making the communication interface 51 exchangeable and connecting a communication interface corresponding to various information devices, the cost of the communication interface can be reduced.
Portability can be further improved.

Although the third embodiment has been described with reference to the case where the communication interface 51 and the storage medium interface 33 are provided, any one of them may be provided.

The configuration of the image data interface 40 according to the second embodiment and the configuration of the communication interface 51 according to the third embodiment differ depending on the form of the input image data. If the image memory interface portion (image data decoding portion) for decoding and outputting to the image memories 22 to 24 can be replaced, the cost of the liquid crystal projector can be reduced.
Portability can be improved.

(Fourth Embodiment) Filter-rotating liquid crystal projectors 10 and 50 according to the first to third embodiments.
Has shown the case where the configuration of the filter plate 12 is three colors of magenta M, yellow Y, and cyan C. However, the filter rotation type liquid crystal projector 60 according to the fourth embodiment is described.
In the following, a case will be described in which the filter plate 61 is set to three colors of RGB and the rotation angle of the filter plate 61 is controlled so as to match the display start timing of each color data RGB.

FIG. 7 is a block diagram showing the configuration of a control system of a filter rotation type liquid crystal projector 60 according to the fourth embodiment. The liquid crystal projector 10 shown in FIG. 2 of the first embodiment and FIG. The same components are denoted by the same reference numerals, and description of the configuration will be omitted.

In FIG. 7, the liquid crystal projector 60 is
A motor control circuit 16a, which is the rotation mechanism 16 in FIG.
Motor 16b, image data interface 21, image memories 22 to 24, memory control circuit 25, D / A converter 26, liquid crystal driver 27, display control circuit 28, rotary encoder 30, CPU 31, program ROM
32, storage medium interface 33, filter plate 6
1 and a display timing control circuit 62.

The filter plate 61 is made of RGB each of 120 °.
It is formed of a disk-shaped transmissive plate colored in three colors (red, green, and blue), and its center is connected to the rotating mechanism 16 and driven to rotate. The rotation speed of the LCD 14
Is set in accordance with the scanning timing of the image signal input to. For example, if the image signal input to the LCD 14 is N
In the case of a video signal based on TSC, in order to form an image for one field in each color of RGB in accordance with a 60 Hz scanning timing at which the video signal for one field is scanned, the frequency is three times 60 Hz. It is rotated at a speed of 180 Hz.

In the filter plate 61, every time the filter plate 61 makes one rotation, the incident light from the lamp 11 is divided into red (R) → green (G) → blue (B) in that order. The light is incident on the condenser lens 13.

The display timing control circuit 62 includes an inverter circuit INV, flip-flop circuits FF1 to FF4, an EXOR gate circuit G1, and an OR gate circuit G2, as shown in FIG.

The flip-flop circuit FF1 repeats the inversion process at the timing of the encode signal 1 input from the rotary encoder 30, and resets the set state of the flip-flop circuit FF2 connected to its output stage. The output of the flip-flop circuit FF1 and the output of the flip-flop circuit FF2 are input to the EXOR gate circuit G1, and the EXOR operation generates a color selection signal R to output to the display control circuit.

The color selection signal R output from the EXOR gate circuit G1 is also input to the flip-flop circuit FF3.
The flip-flop circuit FF2 generates a color selection signal G at the timing of the encode signal 2 input from the rotary encoder 30 based on the color selection signal R, and outputs the color selection signal G to the display control circuit 28.

The color selection signal G, which is the output of the flip-flop circuit FF2, is also input to the flip-flop circuit FF4.
, A color selection signal B is generated at the timing of the encode signal 2 input from the rotary encoder 30 and output to the display control circuit 28.

The OR gate circuit G2 generates a display start signal by performing an OR operation on the encode signals 1 and 2 input from the rotary encoder 30, and outputs the signal to the display control circuit.

Next, the operation of the fourth embodiment will be described.

First, the rotation operation of the filter plate 61 will be described with reference to FIG. FIG. 9 is a diagram showing a rotating state of the filter plate 61, and a light spot in the drawing indicates a position of incident light incident on the filter plate 61 from the light source 11 shown in FIG.

FIG. 14A shows that the boundary between red (R) and green (G) of the rotating filter plate 61 touches the outer edge of the light spot incident from the light source, and the rotation angle at this time is θ0. I do.
FIG. 11B shows that the filter plate 61 further rotates from θ0,
This is a state in which the boundary between red (R) and green (G) has moved to the opposite side of the light spot, and the rotation angle at this time is θ1. FIG. 9C shows a state in which the filter plate 61 is further rotated so that the boundary between green (G) and blue (B) has reached the outer edge of the light spot, and the rotation angle at this time is θ2.

Next, the liquid crystal projector 6 shown in FIG.
The operation of the control system within 0 will be described with reference to the timing chart shown in FIG.

FIG. 10A shows a change in the color of the incident light dispersed by the filter plate 61, and FIG. 10B shows an encode signal 1 output from the rotary encoder 30. (C) shows the encode signal 2 output from the rotary encoder 30, (d) shows the output state of the flip-flop circuit FF1 of FIG. 8, and (e) shows the flip-flop circuit of FIG. FIG. 6F shows an output state of the circuit FF2, and FIG. 6F shows a color selection signal R output from the display timing control circuit 62;
FIG. 7G shows a color selection signal G output from the display timing control circuit 62, and FIG. 7H shows a color selection signal B output from the display timing control circuit 62. ) Shows a display start signal output from the display timing control circuit 62, FIG. 7J shows a display period based on the rotation angle of the display filter plate 61, and FIG.
The display state of a color image on the LCD 14 is shown.

First, in FIG. 7, the motor control circuit 16
a controls the rotation speed of the motor 16b in accordance with the scanning timing of the image signal input to the LCD 14 based on a basic clock timing input from a CPU 31 (not shown), and rotates the filter plate 61 by the motor 16b. By this rotation control, the filter plate 61
As shown in (a), every time a 1/3 rotation is made, the incident light from the lamp 11 is divided into red (R) → green (G) → blue (B) in the order of three colors, and collected. The light enters the optical lens 13.

The rotation angle of the filter plate 61 is detected by the rotary encoder 30, and each time the filter plate 61 is rotated by 120 °, which is one color, as shown in FIG.
The encode signal 2 shown in FIG. 3C is output to the display timing control circuit 62, and every time it detects that the filter plate 61 has rotated 360 °, the encode signal 1 shown in FIG.
Is output to the display timing control circuit 62.

In the image data interface 21, Y (luminance) data and C (color) data are separated from image data input from an external image input device connected to the image input terminal 21a. The color data is further separated into RGB color data. In the image data interface 21, a memory write signal for writing each of the color data RGB into each of the image memories 22 to 24 corresponding to RGB is output to the memory control circuit 25. In accordance with the write control signals output to the memories 22 to 24, the separated color data RGB are output to the image memories 22 to 24 corresponding to RGB, and the color data RGB for one screen is stored. .

The operation timing of writing each color data to the image memories 22 to 24 by the image data interface 21 may be asynchronous with the operation timing of each unit shown in FIG. Is set to a level that does not cause

On the other hand, in the display timing control circuit 62,
When the encode signal 1 is input from the rotary encoder 30 at a timing before the start of the R image display shown in FIG. 10, a display start signal indicating a D / A conversion start timing and a scan start timing (see FIG. 10 (i)). ) Is output to the display control circuit 28. In the display control circuit 28, when a display start signal is input from the display timing control circuit 62, a clock signal for controlling D / A conversion timing is output to the D / A converter 26 and a clock signal for controlling scanning timing. Is output to the LCD 14.

After the display timing control circuit 62 outputs the display start signal, the position of the filter color with respect to the condenser lens 13 of the filter plate 12 is red R during the R image display period shown in FIG. As shown in FIG. 10F, an R image is selected as a display image to be displayed on the LCD 14.
The color selection signal R (active "Hi" level) is output to the display control circuit 28 in the pattern shown in FIG. In the display control circuit 28, a memory read signal R is output to the memory control circuit 25 according to the color selection signal R input from the display timing control circuit 62. In the memory control circuit 25, an operation of reading out the color data R from the image memory 22 that stores the color data R is performed according to the memory readout signal R input from the display control circuit 28, and the read out color data R Output to the D / A converter 26.

In the D / A converter 26, the color data R read from the image memory 22 is D / A (digital / analog) converted in synchronization with the clock timing of the clock signal input from the display control circuit 28. Then, it is output to the liquid crystal driver 27 as an analog image signal R. In the liquid crystal driver 27, an image signal R to be applied to the liquid crystal element of each line in the LCD 14 is generated based on the analog image signal R input from the D / A converter 26, and the scanning input to the LCD 14 by the display control circuit 28. The image signal R is output to the LCD 14 in synchronization with the scanning timing of the timing signal, and the image of the red (R) component is displayed on the screen of the LCD 14.

In displaying the R image, the relationship with the rotation angle of the filter plate 61 shown in FIG.
As shown below the color image display state on the CD 14, the time when the rotation angle θ0 of the filter plate 61 is the time t0 in FIG. 9A and the time t1 when the rotation angle θ1 of the filter plate 61 is the time t1 in FIG. 9B. 9C, the rotation angle θ2 of the filter plate 61
Is the time t2, the display period of the actual R image is
As shown in FIG. 10 (j), the filter plate 61 has a rotation angle θ1.
From time t1 to time t2.

That is, in the liquid crystal projector 60 according to the fourth embodiment, the rotation angle θ of the filter plate 61
In the display timing control circuit 62, the rotation angle of the filter plate 61 is determined by the encode signals 1 and 2 input from the rotary encoder 30 so that the display start signal and the color selection signal RGB are equal to 0, θ1, and θ2. By controlling the output timing, the memory read signal RG output from the display control circuit 28 to the memory control circuit 25 is output.
B, a clock signal output to the D / A converter 26,
The output timing of each clock signal output to the LCD 14 is controlled.

In the display state of the LCD 14 shown in FIG. 10 (k), the memory of the color data GB similarly selected in synchronization with the rotation angle of the filter plate 61 in each of the display states of the G image and the B image. The readout process, the D / A conversion process, and the image display process are performed, and the display operation of the image GB is performed in synchronization with the period t1 → t2 in which the filter plate 61 moves from the rotation angle θ1 to θ2.

Therefore, in the liquid crystal projector 60 according to the fourth embodiment, the color image R displayed on the LCD 14 in accordance with the rotation angle of the RGB type filter 61 is set.
Since the GB display period is controlled, the rotation color timing of the filter plate 61 and the display timing of the corresponding color image can be matched, and the color reproducibility of the projected image can be improved.

In the filter rotating type liquid crystal projector 60 according to the fourth embodiment, the filter plate 61
If the position is set at an appropriate distance from the focal point of the light source, R and G become light separated vertically, so that rewriting of display and synchronization can be achieved, and color reproducibility of a projected image is further improved. be able to.

In the filter rotating type liquid crystal projector 60 according to the fourth embodiment, the case where the RGB type filter plate 61 and the transmission type LCD 14 are used has been described. The MYC type filter plate described in the third embodiment may be used, or a reflection type LCD may be used.

(Fifth Embodiment) In each of the above-described fourth embodiments, the liquid crystal display element, the LCD 1, is used as the display element.
4, the liquid crystal has a characteristic that the display response speed changes under the influence of the ambient temperature. For this reason, in each of the above-described fourth embodiments, even when the rotation speed of the filter plate is constant, the rotation angle of the filter plate and the display operation timing are synchronized. When the speed changes, synchronization may be disrupted and the color reproducibility of the projected image may be reduced.

In the fifth embodiment, the function of setting the display timing so as to change the display response speed of the LCD 14 in response to the change of the ambient temperature will be described in the case where the circuit configuration of the display timing control circuit is changed. I do.

FIG. 11 is a diagram showing a circuit configuration of a display timing control circuit 70 according to the fifth embodiment.
The same circuit components as those of the display timing control circuit 62 shown in FIG. In addition, circuit configurations of other liquid crystal projectors are as follows.
The filter rotation type liquid crystal projector 60 shown in FIG.
Since the configuration is the same as that of FIG.

In FIG. 7, the display timing control circuit 7
0 is the inverter circuit INV and the flip-flop circuit F
F1 to FF4, an EXOR gate circuit G1, an OR gate circuit G2, a temperature sensor 71, a conversion table 72, and a delay circuit 73.

The temperature sensor 71 measures the temperature inside the liquid crystal projector, and converts the measured temperature data into a conversion table 72.
Output to

The conversion table 72 is constituted by a ROM, and a predetermined delay value for changing the display response speed of the LCD 14 based on the temperature (for example, the delay value is set small at a low temperature, and the delay value is set at a high temperature). Is set, and a corresponding delay value is read from the table based on the temperature data input from the temperature sensor 71 and output to the delay circuit 73.

The delay circuit 73 delays the display start signal input from the OR gate circuit G2 according to the delay value input from the conversion table 72 and outputs the delayed signal to the display control circuit 28 in FIG.

Next, the operation of the fifth embodiment will be described.

Display timing control circuit 7 shown in FIG.
The operation within 0 will be described with reference to the timing chart shown in FIG.

In FIG. 12, (a) shows the encoded signal 1 output from the rotary encoder 30 in FIG.
11B shows an encode signal 2 output from the rotary encoder 30, and FIG. 11C shows an output state of the flip-flop circuit FF1 in FIG.
11D shows the output state of the flip-flop circuit FF2 of FIG. 11, and FIG. 11E shows the color selection signal R output from the EXOR gate circuit G1 of FIG. 11 shows a color selection signal G output from the flip-flop circuit FF3 in FIG. 11, and FIG. 11G shows a color selection signal B output from the flip-flop circuit FF4 in FIG. Shows a display start signal output at a low temperature from the delay circuit 73 in FIG. 11, and FIG.
12 illustrates a display start signal output from the delay circuit 73 of FIG. 11 at a high temperature.

The rotation angle of the filter plate 61 shown in FIG.
Each time the rotation of 120 °, which is the color component, is detected, FIG.
(B) is output to the display timing control circuit 70, and every time it detects that the filter plate 61 has rotated 360 °, the encode signal 2 shown in FIG.
Is output to the display timing control circuit 70.

In the image data interface 21, Y (luminance) data and C (color) data are separated from image data input from an external image input device connected to the image input terminal 21a. The color data is further separated into RGB color data. In the image data interface 21, a memory write signal for writing each of the color data RGB into each of the image memories 22 to 24 corresponding to RGB is output to the memory control circuit 25. In accordance with the write control signals output to the memories 22 to 24, the separated color data RGB are output to the image memories 22 to 24 corresponding to RGB, and the color data RGB for one screen is stored. .

The display timing control circuit 70 controls the rotary encoder 30 at a timing before the image display starts.
When the encode signal 1 shown in FIG. 12A is input from the CPU, the display start signal shown in FIG. 12H or FIG. Output to the circuit 28.

At this time, in the display timing control circuit 70, the temperature inside the liquid crystal projector 60 is detected by the temperature sensor 71, and the detected temperature data is output to the conversion table 72. In the conversion table 72, a corresponding delay value is read from a built-in table based on the temperature data input from the temperature sensor 71 and output to the delay circuit 73.

The delay circuit 73 does not delay the display start signal input from the OR gate circuit G2 according to the delay value input from the conversion table 72 when the temperature is low, as shown in FIG. The signal is output to the display control circuit 28 with a delay as shown in FIG. Therefore, when the temperature inside the liquid crystal projector 60 becomes higher than the predetermined temperature, the response operation speed of the LCD 14 becomes faster than at the time of low temperature, and the rotation speed of the filter plate 61 in FIG. The output timing of the display start signal to the display control circuit 28 is delayed so as to delay the minutes.

In the display control circuit 28, the color selection signals RGB input from the display timing control circuit 62
The memory read signals RGB are output to the memory control circuit 25 according to (see FIGS. 12E to 12G). In the memory control circuit 25, an operation of reading the color data RGB from the image memories 22 to 24 storing the color data RGB is performed in accordance with the memory read signal RGB input from the display control circuit 28. RG
B is output to the D / A converter 26.

In the D / A converter 26, the color data RG read from the image memories 22 to 24 is synchronized with the clock timing of the clock signal input from the display control circuit 28 in accordance with the input timing of the display start signal.
B is D / A (digital / analog) converted and output to the liquid crystal driver 27 as an analog image signal RGB. The liquid crystal driver 27 controls the LCD 1 based on the analog image signal RGB input from the D / A converter 26.
Image signals RGB to be applied to the liquid crystal elements of each line in 4 are generated, and are synchronized with the scanning timing of the scanning timing signal input to the LCD 14 by the display control circuit 28.
The image signal RGB is output to the LCD 14, and an image of each color component of red (R) green (G) B (blue) is displayed on the LCD 14.
Will be displayed on the screen.

As described above, in the liquid crystal projector 60 according to the fifth embodiment, the display timing control circuit 70 changes the ambient temperature (low or high) according to the change in ambient temperature.
It has a function of delaying the output timing of the display start signal for setting the start timing of the display operation. Even when the ambient temperature becomes high and the response operation speed of the liquid crystal display element in the LCD 14 increases, the rotation of the filter plate 61 is started. The output timing of the display start signal to the display control circuit 28 is delayed so as to delay the faster time so that the speed can be synchronized with the speed.
Can always be synchronized with the display timing of the color image.

Therefore, it is possible to perform stable image projection while eliminating the influence of a change in the ambient temperature inside and outside the liquid crystal projector 60, and it is possible to improve the reliability of the filter rotation type liquid crystal projector.

(Sixth Embodiment) In each of the above-described first to fifth embodiments, the type of the light source into which the light separated by the filter plate 12 or 61 is incident is not specified.
Depending on the type of light source, the ratio (spectral distribution) of RGB colors contained in the generated light is not uniform but different. For example, if the light source is a halogen lamp,
Low in ingredients. For this reason, there is a possibility that the reproducibility of white displayed when RGB is evenly combined is reduced. Therefore, in the sixth embodiment, a filter plate configured to correct different spectral characteristics depending on the type of the light source will be described.

FIG. 13 is a diagram showing a configuration of a filter plate 80 according to the sixth embodiment. Other circuit configurations of the liquid crystal projector are the same as those of the fifth embodiment shown in FIG. Since the configuration is the same as that of the liquid crystal projector 60, illustration and description of the configuration are omitted.

Referring to FIG. 13, the filter plate 80
It is B type, but the ratio of each color is not 120 °,
The area of R is small, the area of G is medium, and the area of B is large. When a halogen lamp is used as the light source, this division ratio has a spectral distribution in which the R component is large and the B component is small, so that the R area is reduced in the filter plate 80 so as to correct the spectral distribution, The area is large.

If the encoding mark detected by the rotary encoder 30 is cut in the filter plate 80 so as to reflect the changed RGB ratio, the filter plate 80 shown in FIG. Can be projected without changing the configuration of the filter rotation type liquid crystal projector 60 shown in FIG.

Next, the operation of the sixth embodiment will be described.

The operation in liquid crystal projector 60 shown in FIG. 7 will be described with reference to a timing chart shown in FIG.

FIG. 14A shows an encoded signal 1 output from the rotary encoder 30 shown in FIG.
FIG. 7B shows the rotary encoder 3 shown in FIG.
FIG. 3C shows an encoded signal 2 output from the signal 0.
8 shows a color selection signal R output from the EXOR gate circuit G1 in FIG. 8, and FIG. 8D shows a color selection signal G output from the flip-flop circuit FF3 in FIG. 8 shows the color selection signal B output from the flip-flop circuit FF4 in FIG. 8, and FIG.
7A shows a display start signal output from the gate circuit G2, and FIG. 7G shows a display period on the LCD 14 in FIG.

First, in FIG. 7, the motor control circuit 16
a controls the rotation speed of the motor 16b in accordance with the scanning timing of the image signal input to the LCD 14 based on a basic clock timing input from a CPU 31 (not shown), and rotates the filter plate 80 by the motor 16b. By this rotation control, the filter plate 61
As shown in (a), every time a 1/3 rotation is made, the incident light from the lamp 11 is divided into red (R) → green (G) → blue (B) in the order of three colors, and collected. The light enters the optical lens 13.

The rotation angle of the filter plate 80 is determined by the encoding signal 2 shown in FIG. 14 (b) each time the encoding mark is detected by the rotary encoder 30 and the rotation of the filter plate 61 by one color is detected. The signal is output to the display timing control circuit 62 and the filter plate 80
毎 Every time rotation is detected, the encode signal 1 shown in FIG.

In the image data interface 21, Y (luminance) data and C (color) data are separated from image data input from an external image input device connected to the image input terminal 21a. The color data is further separated into RGB color data. In the image data interface 21, a memory write signal for writing each of the color data RGB into each of the image memories 22 to 24 corresponding to RGB is output to the memory control circuit 25. In accordance with the write control signals output to the memories 22 to 24, the separated color data RGB are output to the image memories 22 to 24 corresponding to RGB, and the color data RGB for one screen is stored. .

On the other hand, in the display timing control circuit 62,
When the encode signal 1 is input from the rotary encoder 30 at a timing before the start of the R image display shown in FIG. 14, a display start signal indicating a D / A conversion start timing and a scan start timing (see FIG. 14F). ) Is output to the display control circuit 28. In the display control circuit 28, when a display start signal is input from the display timing control circuit 62, a clock signal for controlling D / A conversion timing is output to the D / A converter 26 and a clock signal for controlling scanning timing. Is output to the LCD 14.

After the display timing control circuit 62 outputs the display start signal, the position of the filter color with respect to the condenser lens 13 of the filter plate 12 is red R during the R image display period shown in FIG. As shown in FIG. 10F, an R image is selected as a display image to be displayed on the LCD 14.
The color selection signal R (active "Hi" level) is output to the display control circuit 28 in the pattern shown in FIG. In the display control circuit 28, a memory read signal R is output to the memory control circuit 25 according to the color selection signal R input from the display timing control circuit 62. In the memory control circuit 25, an operation of reading out the color data R from the image memory 22 that stores the color data R is performed according to the memory readout signal R input from the display control circuit 28, and the read out color data R Output to the D / A converter 26.

In the D / A converter 26, the color data R read from the image memory 22 is D / A (digital / analog) converted in synchronization with the clock timing of the clock signal input from the display control circuit 28. Then, it is output to the liquid crystal driver 27 as an analog image signal R. In the liquid crystal driver 27, an image signal R to be applied to the liquid crystal element of each line in the LCD 14 is generated based on the analog image signal R input from the D / A converter 26, and the scanning input to the LCD 14 by the display control circuit 28. The image signal R is output to the LCD 14 in synchronization with the scanning timing of the timing signal, and the image of the red (R) component is displayed on the screen of the LCD 14.

In displaying the R image, the relationship between the rotation angle of the filter plate 80 shown in FIG. 13 and the rotation position of the filter plate 80 as shown below the image display period on the LCD 14 in FIG. Assuming that the time when moves from B to R is time t0 → t1 and the time when the rotational position of the filter plate 80 is in the R area is time t1 → t2, the actual R image display period is shown in FIG. Thus, the period during which the filter plate 80 rotates is changed from t1 to t2.

Also, during the display period of the LCD 14 shown in FIG. 14 (g), in each display state of the G image and the B image, the color data GB selected similarly in synchronization with the encoding mark of the filter plate 80 is also displayed. Memory read processing,
Period in which the D / A conversion processing and the image display processing are performed, and the rotation position of the filter plate 80 moves from R to G, from t1 to t
2, and the display operation of the image GB is performed in synchronization with the period t1 → t2 in which the image moves from G to B.

That is, in the liquid crystal projector 60 according to the sixth embodiment, the display timing control circuit 62 changes the RGB division ratio of the filter plate 80 so that the RGB division ratio matches the color division ratio. The rotation color of the filter plate 80 is determined based on the encoding signals 1 and 2 input from the CPU, and the output timing of the display start signal and the color selection signal RGB is controlled, so that the display control circuit 28 outputs the color to the memory control circuit 25. The output timings of a memory read signal RGB, a clock signal output to the D / A converter 26, and a clock signal output to the LCD 14 are controlled.

Therefore, in the liquid crystal projector 60 according to the sixth embodiment, the R-
The GB color division ratio is changed so as to correct the spectral characteristics of the light source, and the display period of the color image RGB to be displayed on the LCD 14 is controlled in accordance with the color division ratio. , And an image with an improved color balance can be projected. Further, since the color balance can be corrected only by the filter plate 80, an inexpensive light source can be used, and the cost of the filter-rotating liquid crystal projector can be reduced.

In each of the first to sixth embodiments, a case has been described in which a rotary filter plate is used. However, it is also possible to use a trackless moving filter that is color-divided. In this case, the moving position of the moving filter is detected by the position detecting sensor, the spectral color is determined based on the detected moving position, and the color RGB of the color data for driving the LCD 14 is selected. The liquid crystal projector described in each of the first to sixth embodiments can be configured.

In each of the first to sixth embodiments, the case where the transmissive LCD 14 is used has been described. However, a reflective LCD may be used, or other display elements may be used. For example, a DMD (digital micromirror device) or the like may be used.

[0177]

According to the projector of the first aspect of the present invention, the amount of transmission of incident light incident from the light source is increased as compared with a color filter which is divided into three primary colors, RGB, so that a bright projected image can be formed. Can be displayed. In addition, since display is performed by interlaced scanning, the display speed can be reduced, a display element that is a display device that operates at a low speed can be used, and the configuration of a display control circuit can be simplified and cost can be reduced.

According to the projector of the second aspect, the timing of writing to the image memory does not need to be synchronized with the timing of driving the display element, and depends on the scanning frequency of the input color image signal. The image can be projected without the need.

According to the projector of the third aspect of the invention, it is possible to configure a projector which can be directly connected to an information device for processing digital data, and to connect the image data interface to a portable terminal having a built-in data communication function. By doing so, it is possible to configure a projector that downloads and uses image data from an information device installed at a distant place during projection.

According to the projector of the fourth aspect, the cost of the projector can be reduced and portability can be improved.

According to the projector of the present invention, the movable color filter can control the display period of the color image displayed on the display element in accordance with the color boundary at the time of movement. The transition timing of the color of the color filter can be matched with the display timing of the corresponding color image, and the color reproducibility of the projected image can be improved.

According to the projector of the sixth aspect of the present invention, it is possible to perform stable image projection while eliminating the influence of a change in the display response speed of the display element due to a change in the ambient temperature inside and outside the projector. Performance can be improved.

According to the projector of the present invention, the color division ratio of the movable color filter is changed so as to correct the spectral distribution of the light source, and the color displayed on the display element in accordance with the color division ratio. The display period of the image can be controlled, the spectral distribution of the light source can be canceled by the color area ratio of the color filter, and an image with improved color balance can be projected. Further, since the color balance can be corrected only by the color filters, an inexpensive light source can be used, and the cost of the projector can be reduced.

[Brief description of the drawings]

FIG. 1 is a diagram showing a main configuration of a filter rotation type liquid crystal projector 10 according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing a circuit configuration of a control system in the liquid crystal projector 10 of FIG.

FIG. 3 is a timing chart showing the operation of each unit in the liquid crystal projector 10 of FIG.

4 is a diagram illustrating an interlacing operation when displaying an image on the LCD 14 of FIG. 2;

FIG. 5 is a block diagram showing a circuit configuration of an image data interface used in a filter rotation type liquid crystal projector according to a second embodiment of the present invention.

FIG. 6 is a block diagram illustrating a circuit configuration of a main part of a filter rotation type liquid crystal projector 50 according to a third embodiment of the present invention.

FIG. 7 is a block diagram showing a circuit configuration of a filter rotation type liquid crystal projector 60 according to a fourth embodiment of the present invention.

8 is a diagram showing a circuit configuration of a display timing control circuit 62 in FIG.

9A and 9B are diagrams showing a rotation state of the filter plate 61 of FIG. 7, and FIG. 9A shows a case where the rotation angle is θ0;
FIG. 3C shows that the rotation angle is θ2 when the rotation angle is θ1.
Is shown.

FIG. 10 is a timing chart showing the operation of each unit in the liquid crystal projector 60 of FIG.

FIG. 11 is a diagram showing a circuit configuration of a display timing control circuit used in a filter rotation type liquid crystal projector according to a fifth embodiment of the present invention.

12 is a timing chart showing the operation of each unit in the display timing control circuit 70 of FIG.

FIG. 13 is a diagram illustrating a configuration of a filter plate 80 used in a filter rotation type liquid crystal projector 60 according to a sixth embodiment of the present invention.

FIG. 14 shows a display timing control circuit 62 in a filter rotation type liquid crystal projector 60 according to the sixth embodiment.
5 is a timing chart showing the operation of each unit in FIG.

FIG. 15 is a diagram showing a configuration of a main part of a conventional filter rotation type liquid crystal projector.

[Explanation of symbols]

 10, 50, 60 Liquid crystal projector 11 Lamp 12, 61, 80 Filter plate 13 Condenser lens 14 LCD 15 Projection lens 21, 40 Image data interface 22 Image memory (for R) 23 Image memory (for G) 24 Image memory (B 25) Memory control circuit 26 D / A converter 27 Liquid crystal driver 28 Display control circuit 29, 62, 70 Display timing control circuit 30 Rotary encoder 31 CPU 32 Program ROM 33 Storage medium interface 34 Storage medium 41 Y / C separation circuit 42 RGB Decoding circuit 43 Clock generation circuit 44-46 A / D converter 51 Communication interface

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI G09G 3/36 G09G 3/36 H04N 9/31 H04N 9/31 C

Claims (7)

[Claims] A light emitted from a light source is transmitted through a color-divided rotary color filter to selectively separate the light, and the light transmitted through the rotary filter is made incident on a liquid crystal display element to be converted into a spectral color. A color image signal is input by a display control circuit to drive the display element to form a color display image, and the color display image is enlarged and projected by a projection lens. The color is divided into three colors of magenta (M), yellow (Y), and cyan (C), and the display control circuit determines each spectral color selected from the rotation position of the rotary color filter, and determines this. A projector characterized in that the input color image signal corresponding to each of the spectral colors is selected, and the display elements are interlacedly driven to form a color display image. 2. The method according to claim 1, wherein the light emitted from the light source is transmitted through a color-divided rotary color filter to selectively separate the light, and the light transmitted through the rotary filter is incident on a display element. A display control circuit that selects a color image signal to be input by a display control circuit, drives a display element to form a color display image, and enlarges and projects the color display image by a projection lens. Further comprising an image memory for storing a color image signal for each color, storing an input color image signal for each color in the image memory, and determining each spectral color selected from a rotation position of the rotary color filter; A color image signal corresponding to the determined spectral color is read out from an image memory, and the display elements are interlaced to form a color display image. Kuta. 3. The image processing apparatus according to claim 2, wherein the display control circuit further includes a digital-compatible image memory interface that enables digital image data to be stored in the image memory as the input color image signal. Item 2. The projector according to Item 2. 4. The projector according to claim 2, wherein said image memory interface is replaceable. 5. A light emitted from a light source is transmitted through a color-divided moving color filter to selectively split light, and the light transmitted through the moving filter is made incident on a display element, and the light is emitted according to the spectral color. A display control circuit for selecting a color image signal to be input by a display control circuit, driving a display element to form a color display image, and enlarging and projecting the color display image by a projection lens. The type color filter detects a color boundary at the time of movement, determines an irradiation period of each spectral color to be selected, and synchronizes with the determined irradiation period of each spectral color to synchronize the input period corresponding to each spectral color. A projector characterized by selecting a color image signal and driving the display element to form a color display image. 6. The display control circuit further includes a temperature detection circuit for detecting an ambient temperature, and a delay circuit for delaying a drive start timing for driving the display element based on the detected temperature. The projector according to claim 5, wherein: 7. A light emitted from a light source is transmitted through a color-divided moving color filter to selectively split light, and the light transmitted through the moving filter is incident on a display element, and the light is emitted according to the spectral color. A color image signal is selected by a display control circuit to drive a display element to form a color display image, and the color display image is enlarged and projected by a projection lens. The ratio of each color is set according to the spectral distribution of the light source, and the display control circuit detects a color boundary when the movable color filter moves, and determines an irradiation period of each selected spectral color. Synchronizing with the determined irradiation period of each spectral color, selecting the input color image signal corresponding to each spectral color and driving the display element to form a color display image. Projector.