JPH06343178A - Three primary colors time division flash lighting type liquid crystal projection type color picture display device - Google Patents

Abstract

PURPOSE:To provide a liquid crystal projection type picture display device provided with color resolution three to six times as much as a conventional case by one black/ white LCD. CONSTITUTION:Standard color television video signals are converted to 1/4 time- compressed time division three primary color video signals and the three primary color video signals of R, G and B are written to one black/white LCD (1) with equivalent time intervals in a standard field time. Blank time generated for each writing of the primary video signal is intentionally provided, the response time of liquid crystal is supplied, also LCD lighting is synchronously performed by a white flash lamp (3) corresponding to the primary color video pictures for which the writing is completed after the second half of the blank time and color picture display is surface sequentially performed by an electrically controlled three primary color modulator (2). Then, further, the LCD color pictures are shifted to the middle of the lines of odd numbered and even numbered field pictures and complemented by a light deflector (5), are magnified and projected by a projection lens (4) and high resolution color picture display is performed by a low picture element integrated degree LCD.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal projection type color image display device.

[0002]

2. Description of the Related Art A liquid crystal projection type color image display device uses three small black-and-white liquid crystal image display panels (hereinafter abbreviated as black-and-white LCDs), and a continuous white light source to generate red (R), Separation into three primary color lights of green (G) and blue (B) by a three-primary color separation dichroic mirror, and R, G, and B three LCDs are independently illuminated, and the three LCD primary color display images are three primary colors. This is a method in which a single dichroic mirror for synthesis optically matches and synthesizes one three-primary-color LCD image and a projection lens enlarges and projects it on an external screen. A mechanical fine adjustment mechanism is required to match and combine the three LCD primary color images, and the flatness of the composite mirror, and the displacement of the three primary color images due to the curved deformation of the base due to an increase in size and the impact, the three primary color images Due to the above-mentioned distortion of the projection magnification, it is difficult to perfectly match and compose the complete three-primary-color images over the entire projected image, and the size becomes large and the cost becomes high.

A color filter of RGB three primary colors is built in all integrated pixels of one LCD in a dot-sequential manner on a pixel-by-pixel basis, and only the corresponding primary color pixel portion is written and displayed by the three primary color video signals, and the other primary color pixel portions are displayed. To display without
A projection type color image display device using a single-panel color LCD has a drawback that the color display resolution is 1/3. Further, in order to obtain the same color resolution as the method using three LCDs, three times as many pixel integrations are required, and there is a problem that the LCD becomes expensive due to a reduction in manufacturing yield rate. Further, there is a problem that the temperature inside the LCD section rises due to light absorption and heat generation of the three primary color filters built into the LCD, the display contrast deteriorates, and the amount of projected light is limited.

The standard television system in the world divides one complete still image into two even and odd fields and transmits them in a time division manner in order to compress the transmission frequency band to 1/2. A two-to-one interlace method is generally used in which the middle of even and odd field line images are complemented in time and space by utilizing visual afterimages to display images. This is also a method intended for reducing flicker and continuity of moving images. In the case of a cathode ray tube image display, by appropriately selecting the afterimage time when the phosphor emission spontaneously disappears, the natural continuity of a moving subject and the increase in vertical resolution of a still image can be obtained from the visual afterimage characteristic. Was a method that was established because of the CRT image display.

In the case of liquid crystal image display, one liquid crystal pixel itself is an electric capacitance, and the response of the liquid crystal itself is improved by a unique self-capacitive memory action based on the sample-hold writing principle of liquid crystal image display. Even if the speed is reduced to 1 mS or less, in principle, afterimages are displayed until the writing of the next field, and there is a problem of deterioration in resolution due to 2: 1 interlace, which cannot be solved only by increasing the response of the liquid crystal itself. It was

In order to display an image equivalent to that of a cathode ray tube under the 2-to-1 interlacing condition used in a standard television or the like, one high-speed response 240-line LCD capable of displaying 240 lines of image for one field is used. ,
Image information of odd and even fields can be written and displayed alternately in a time-division manner. Interlaced scanning image display corresponding to 2: 1 interlace can be performed optically by scanning line image configurations of odd and even fields. By the minute deflection of the size equivalent to the upper and lower half pixels, 240 for 2 fields
Line configuration It is necessary to interpolate the middle portions of the line pixels of the LCD image with each other in terms of time and space to display the whole line image.
This is a principle problem of LCD image display which cannot be solved by simply making an LCD having 480 lines. The present situation is that the still image vertical resolution is deteriorated due to deterioration due to double display of a moving image and even when a line-speed doubled scan conversion non-interlaced image is displayed, and no substantial improvement is made and it is put to practical use.

[0007]

SUMMARY OF THE INVENTION The first object of the present invention is to obtain the image display with the maximum color resolution by minimizing the number of pixels integrated in the LCD. The high-resolution color display of the conventional LCD has been performed by increasing the total number of pixels of one LCD exclusively, but a high-speed response black and white LCD with a 240-line structure, which is half the standard effective line number of 480 lines, is used. A high light output liquid crystal projection type high resolution color image display device in which the color image display capability is tripled by the three primary color time-division drive display and at the same time there is no color shift of the three primary color images in principle. Based on that, 2 to 1
A second purpose is to display a color image corresponding to 480 lines by interlaced scanning corresponding to interlace, and a high resolution color image display up to about 6 times that of a conventional liquid crystal projection type color image display device by optical minute optical deflection. The present invention is realized by using a single black-and-white LCD having a 240-line structure, and it is an object to provide a liquid crystal projection type color television receiver that is smaller, lighter, cheaper and has higher performance.

[0008]

In order to achieve the above-mentioned object in an example applied to an existing standard color television system, in order to achieve the above-mentioned object, the total number of integrated pixels for one field is formed by an XY matrix configuration with active transistors. 240 lines x 4
It is necessary to use a black-and-white LCD with 80 dots and a response of the liquid crystal itself of about 1 mS.

The signals were simultaneously transmitted in parallel in RGB and demodulated,
RGB standard color image signals at standard scanning speed are converted into digital video signals at the standard scanning speed in parallel with the three primary colors independently, and once stored in the field memory in standard field time units, the standard one field time is divided into three equal time intervals. RG
A means for converting into a B sequential 1/4 hour compression time division three primary color video signal and reading the signal is provided, and means for writing and displaying the read signal on one high-speed responsive monochrome LCD panel.

At the end of writing of one primary color video signal of each primary color video signal which is written three times at equal time intervals in one field time (about 16.7 mS), the three primary color video signals which have been compressed and converted for 1/4 time described above. By intentionally creating a large blank time for each time-divided primary color video signal that occurs until the start of writing of the next primary color video signal to be written, the rise response time of the liquid crystal is secured, and within that blank time. In the second half of
By means of performing intermittent flash illumination of the same primary color as the written primary color video signal evenly over the entire black and white LCD, three primary color images are combined in a time-sharing manner with one high-speed response black and white LCD, which is three times as large as the conventional one. Realized high resolution color image display,
The high-resolution color original image is basically configured to be enlarged and projected on a screen by a projection lens.

As a means for visually doubling the number of line pixels in the vertical direction by interlaced scanning, which corresponds to 2-to-1 interlace, visually, an RGB time-division color image display device using a 240-line LCD having the above-mentioned projection structure is used. Basically, 2 for the even / odd field display image
240 line LC displayed in odd and even fields, which is fluctuatingly moved up and down by the optical minute deflection means of the value
Pixel complementing the intermediate position of the D image in time and space to display a still image and a moving image with two bodies and one interlace equivalent to the CRT display, and enlarge and project as a color image of all lines on a large screen. Is.

[0012]

Although it is not practical for a direct-viewing type liquid crystal television, it is extremely effective for a magnifying projection type screen-television configuration, and it is possible because of the projection configuration. 1 to 2-3 inch small black and white LCD, RGB time division drive 3
Since it is a method of synthesizing three primary color colors in time and space that can obtain a double color image display resolution, in principle, the color shift of the three primary color images does not occur at all.
Compared to the individual liquid crystal projection color television configuration method, it is possible to simultaneously reduce the number of devices used, make adjustment-free colors, reduce size and weight, and reduce costs. Compared with the conventional built-in color filter method with one LCD, the light absorption and heat generation in the LCD is reduced to 1/3 or less, and the projected light quantity is increased by about 3 times and the color resolution of 3 times is obtained at the same time. There is. For example,
Existing standard 480-line LCD (total number of pixels = 640Hx
480V) and diagonal displacement half-pixel light deflection complementation has more than double resolution (corresponding to 960 RGBX 960 lines)
It can be applied to liquid crystal color projection televisions that are comparable to the high definition televisions of the above, and it is possible to reduce the cost of high definition projection type color television receivers by using a monochrome LCD with a relatively small number of pixels. The advantage is that both high resolution colorization can be achieved.

[0013]

1 is a central sectional view showing the structure of an embodiment of the present invention. One high-speed responsive black-and-white LCD is a standard color TV with RGB simultaneous parallel three primary color video signals.
It is converted into R, G, and B sequential time-division RGB video signals compressed for ¼ hour, and written and displayed at time intervals obtained by dividing the standard one field time into three equal parts. About 0 in the latter half of the blank time and the latter half including the blanking time, which is intentionally provided so as to generate a blank time between the end of writing the video signal in the time-division primary color unit and the start of writing the next primary color video signal. At the time of 0.5 mS, a single xenon flash lamp provided at the rear side intermittently flashes a monochrome LCD through the bandpass filter 32 and the field lens 25.
Of the electric control 3 primary color modulator section, which is provided immediately after the projection lens, so that the entire surface of the
An RGB primary color shown in FIG. 2 is provided with a function of electrically selectively transmitting one primary color, and RG is displayed on one black and white LCD.
B The primary color video signal to be written by time division and the same primary color light are electrically selected and changed in color, and a color image is reproduced and displayed sequentially in RGB in a time division manner, and the color image is projected onto an external screen by a projection lens unit. It is configured so that it is enlarged and projected.

Further, a 45-degree reflection mirror 51, which is provided between the black and white LCD and the projection lens, is provided by being glued to the electric light deflection / decomposer, and the mirror surface is formed into an odd field image and an even field image. Correspondingly, it is possible to electrically shift the half pixel size up and down, optically display a 2: 1 interlaced image, and obtain twice the vertical resolution.

FIG. 3 is a diagram showing waveforms and timing relationships of the respective parts according to the above-mentioned basic structure. (A) is NTS
C standard composite color video signal, (b, c, d) are standard RG
B3 primary color video signal, (e) odd / even field discrimination output signal, (f) standard vertical sync signal, (g) triple speed vertical sync signal, (h, i, j) RGB time division time division standard The signal and the color change timing signal of the electric three primary color modulator, (k) shows the 1/4 hour compression time-division RGB video signal waveform, and (l) shows the timing of flash illumination of the flash lamp.

The black-and-white LCD is required on the premise that it has an XY matrix structure of an active type thin film polysilicon transistor in which a high-speed response liquid crystal material of about 1 mS is enclosed, and the transistor portion is schematically shown by a black dot. However, in the case of NTSC standard color television system,
It is possible to display a color image with horizontal resolution of about 320 RGB lines and vertical resolution of about 480 lines. In a standard television transmission, one complete frame image is transmitted in time division in even and odd two fields, and effective 240 scan line images of odd and even fields are woven exactly in the middle of each other, and it is temporal and spatial. The line pixel is complemented and the frame image corresponding to 480 lines is visually observed. In order to obtain still image resolution and moving image resolution faithful to standard television broadcasting, a half line LCD with a total LCD integrated pixel count of 480 pixels in the horizontal direction and 240 pixels in the vertical direction is used, and two pairs of even and odd field images are used. Interlaced scanning corresponding to 1 interlace is 480 RGB in the horizontal direction due to the slight optical deflection of the upper and lower binary values in the optical line direction.
It is desired to display full-color X480 lines and full-color full-color images.

A common method for time-division driving three primary color video signals to display a color image is to convert standard analog RGB video signals demodulated in parallel and simultaneously into video signals compressed in RGB order for 1/3 hour and display them on a cathode ray tube. This is a method that is established in the case of luminescence responsiveness in which luminescence is spontaneously extinguished in a few mS after stimulation with an electron beam, such as phosphor luminescence.

In the case of a liquid crystal image display panel, one liquid crystal pixel itself has the function of a capacitor having a liquid crystal layer as a dielectric in principle, and the sampling writing voltage of the video signal is stored until the next sampling writing. It exhibits retained characteristics, and the optical response rises depending on the liquid crystal response, and is maintained in principle until the next rewriting. Actually, it self-discharges due to the intrinsic resistance of the liquid crystal itself and the blocking resistance of the pixel TFT, but even if the response of the liquid crystal is as fast as 1 mS, about 100 mS shows a unique optical response that is stored without rewriting. Degradation due to double image display caused by using a 480-line LCD is also caused by this, and image display faithful to 2: 1 interlace cannot be performed.

In the RGB time-division image display by the liquid crystal image display panel, in consideration of the light response characteristic of the liquid crystal image display device, ¼ hour compression time-division RGB video signal conversion is performed and divided into three equal parts in a standard one field time. By writing and displaying the RGB primary color image signals on the LCD three times at predetermined time intervals, a blank time is created between the writing end time of a certain primary color video signal and the writing start time of the next primary color video signal, and at least, A liquid crystal response time of 1 mS and a flash illumination time of about 0.5 mS are obtained, and the response time of liquid crystal molecules is longer than that in the case of 1/3 hour compression time-division RGB video signal conversion to display an image with good contrast. The circuit must be pre-configured so that

FIG. 4 shows that one black-and-white LCD writes and displays the time-division RGB color video signals compressed for ¼ hour.
In the latter half of the above blank time, xenon with synchronized flash illumination
It is a drive circuit of a flash lamp. A main AC power supply, which is a commercial AC power supply converted to a DC voltage of about 250 V by a double-wave voltage doubler rectification circuit, is connected to a xenon flash lamp in parallel via a current suppressing resistor R _Y. After fully charging the discharge capacitor C _F , the flash lamp is induced to discharge by applying a trigger voltage of several thousand volts to the trigger electrode provided in close contact with the outer wall of the glass tube of the flash lamp, causing a flash of about 0.5 mS. It is used as a light source for LCD lighting by producing a typical white light emission. The emission timing circuit is 25
The 0V DC voltage is resistance-divided by R ₁ and R ₂ to charge the trigger capacitor C _T , the positive potential side thereof is connected to one end of the primary winding of the trigger transformer T _T , and the other end is MO.
Connected to the drain side of the S transistor T _R, and connect the source to the common ground line, the gate terminal of the MOS transistor, a 3-speed vertical synchronizing signal 3f _V a flash timing pulse which is delayed until the second half of the idle time When you type. The electric charge of the trigger capacitor C _T is rapidly discharged through the primary winding of the trigger transformer, and a high voltage pulse of several thousand volts is induced and generated on the secondary side of the trigger winding, and the electric charge C _F of the heavy discharge capacitor is generated in the flash lamp. (1/2 CV _F ² single-shot energy is about 0.5 Joule) is instantly discharged and emitted,
This is repeated 180 times per second to perform the flash illumination of the black and white LCD, and the projection light amount substantially equal to the white illumination light equivalent to about 90 watts can be obtained.

Another method of the three primary color flash illumination shown in FIG.
Three xenon flash lamps dedicated for each of the G and B primary colors, and an R reflection dichroic mirror (RD)
M) 28 and B reflection dichroic mirror (B / DM) 2
This is a method of combining 7 in the form of X, illuminating three white xenon flash lamps provided behind it in a cyclic manner in a cyclic manner, and illuminating the three primary colors through a three primary color separation cross dichroic mirror. This method has an advantage that the amount of illumination light can be increased by about 3 times or the lighting life can be extended by about 3 times compared with the case of one unit, and further, the electro-optical three primary color modulator described above can be omitted.

A method of displaying an image of 480 lines which has been interlaced and scanned by one 240 line LCD is as follows. The odd field image and the even field image are synchronized with the 2: 1 interlace of the standard television and the 45 degree reflection mirror 51 is used.
Or reciprocally rotate by a small angle of 0.1 degree, or, as in the embodiment of FIG. 1, the 45 degree reflection mirror 51 is placed at the center of the movable part of the electric light deflection decomposer similar to the structure of the electromagnetic speaker. The 45-degree reflecting mirror surface provided by gluing is oscillated up and down in a binary manner by about 0.05 mm, and the LCD center position with respect to the projection lens optical axis center is set to about 0.06 mm for a half pixel size pitch. It becomes possible by the method of optically shifting and magnifying and projecting on a screen. 45 degree reflection mirror 5
The transition timing of 1 is 1 for each standard odd / even field.
A time-division R primary color video signal compressed for / 4 hours, the transition is completed within about 4 mS from the start to the end, and white flash illumination of about 0.5 mS can be performed in the latter half of the blank time for each primary color video signal. For example, an interlaced scanning color image display equivalent to a cathode ray tube can be displayed.

The structure of the electric optical deflector decomposer / decomposer is such that a small disc-shaped white 45-degree reflecting mirror 51 is bonded at three points to the central portion of a leaf spring disc 52, which is formed by radial holes, to form a leaf spring disc 52. A cylindrical permanent magnet 54 and a sliding central shaft are integrally fixedly provided on the coaxial center portion on the opposite surface to form a movable mirror portion. It has a structure similar to that of an electromagnetic speaker, in which a movable mirror portion is fixedly integrated with a spacer 59 so that the movable mirror portion can slide up and down in a soft magnetic iron plate cylindrical magnetic path 56 having a bearing and an exciting coil 57 in the center. The electromagnetic coil 57 is 2: 1
The mirror surface is driven by a maximum of 0.1 mm by driving with a binary current corresponding to interlace. In addition, the movable cylindrical permanent magnet 54 and the fixed soft magnetic iron plate cylindrical magnetic path 56.
Is bonded via a transient vibration absorbing damper rubber 55 to limit the movable range and absorb the transient vibration.

The electrically controlled three-primary-color modulator section shown in the embodiment of FIG. 1 is an electrically-controlled three-primary color filter that instantaneously changes the color by optical rotation due to the electro-optical effect. The principle is that an optical retardation plate (21, 22) having a birefringence index inserted between polarizing plates (23, 26) under a light-shielding condition causes two orthogonal polarization components E _X , E _Y of a light wave. Causes a difference in the propagation speed inversely proportional to the square root of the square of the refractive index of the wavelength order,
The color is changed by the interference effect of light appearing on the output side.

Usually, it is an electrical application of a method called a current color polarized light (Iwanami Zensho / Applied Optics P201 / Kubota) by optical rotation. In short, a unidirectionally stretched plastic or the like is placed between two polarizing plates under light shielding conditions. It is based on the same principle as that of inserting and obtaining various kinds of color development in proportion to its thickness. The optical retardation plate is made of plastic and is approximately 900 nm.
Fixed optical retardation plate 22 of about 0 to 400 nm electrically
The electro-optical degree adjusting phase difference plate 21 for controlling the optical phase difference of is superposed. FIG. 2 shows the spectral transmission characteristics of the RGB three primary colors of the embodiment showing the degree of color development due to the optical rotation.

The spectral transmission characteristic of optical rotation by the optical retardation plate 21 is I _OUT = I _IN · sin ² · [πΓ / λ]
When the optical phase difference Γ nm is changed by the theoretical formula of, the maximum transmittance I _OUT can be generated for every odd multiple of 1/2 of the desired wavelength λnm. For example, G (green, λ = 5
40 nm), Γ _G (270 nm, 810 nm,
The maximum transmittance is 1350 nm. B (blue, λ = 4
40 nm is Γ _B (220 nm, 660 nm, 110
0 nm). At R (red, λ = 620 nm), Γ _R (3
10 nm, 930 nm, 1550 nm). It shows a maximum transmittance of 100% due to constructive interference, but low-order constructive interference shows a broader spectral distribution band and higher-order constructive interference shows a characteristic that it is practically used as a three-primary color image display. The obtained optical phase difference Γ nm is Γ _R = 9
It is limited to 3 points near 30 nm, Γ _G = 1350 nm, and Γ _B = 1100 nm. Spectral transmission characteristics of the three primary colors of the current-color polarized light that are naturally obtained by optical rotation show a characteristic of increasing again at the skirt as shown by the dotted line, and the color purity decreases due to color mixing of unnecessary light. Red part 660nm
The band limiting filter 32 that cuts off the above unnecessary light is provided on the light source lamp side for correction, and is used to obtain the spectral transmission characteristics of the three primary color lights that pose no practical problems.

The reason for separating the fixed optical phase difference plate 22 and the electrically variable optical phase difference plate 21 in the three primary color modulator part of FIG. 1 is that each current color is selected from all the optical phase differences Γnm necessary for the three primary color development. This is because the stretched plastic plate is allowed to share about 900 nm, which is common to the above, and the electrically variable amount is set to 0 to 350 nm to lower the driving voltage. The perspective reference diagram shown in FIG. 1 (A) shows the conceptual structure of the electrodes of the electrically variable optical phase difference plate 21.
Using an electro-optic ceramic material plate called LZT21, and the drive electrodes 21 _d of the comb on its surface, the ground electrode 2
1 _e is formed by vapor deposition, and a voltage is applied between both electrodes to perform PLZ.
The electric field generated in the lateral direction in the T material causes a difference in refractive index n + Δn in the direction of the electric field and a refractive index n in the direction perpendicular to the electric field to generate an optical phase difference. The variable optical phase difference is shared among them. Furthermore, the actual configuration for lowering the drive voltage is as follows: electrode pitch 0.5 mm, electrode width 0,05 m
m, depth 0, 1 mm, which is composed of comb-shaped electrodes similar to the conceptual diagram of a groove-embedded electrode structure, and RGB color development has a variable optical phase difference of 30 nm (R), 200 nm (B),
By selecting a ternary supply voltage of 350 nm (G), it is possible to instantly change the color to one of the three primary colors of 0.1 mS or less and select the primary color.

FIG. 5 shows the video signal of a standard color television.
It is a block circuit diagram for explaining an electric circuit for converting into a double speed time division RGB video signal. FIG. 6 shows an output waveform and timing relationship diagram of the main block circuit corresponding to the electric circuit of FIG. 5 to explain the operation.

In the example in which the composite video signal input of the NTSC standard color television system is applied to the video input terminal 60 of FIG. 5, it is added to the YC separation circuit 62 via the buffer video amplifier 61. The luminance video signal Y and the carrier chromaticity signal C are separated, the delay times of both are matched, and then both are input to a standard RGB color demodulator 70,
First, several cycles of a reference phase tone carrier wave horizontally inserted in the blanking section are extracted, and a continuous constant amplitude 3.58 M _Z (f _SC ) reference color subcarrier wave synchronized with phase matching is generated. The reference color subcarrier and the color subcarrier chromaticity signals that have been subjected to quadrature modulation and band compression transmission by suppressing the color subcarrier are subjected to synchronous product detection, and RY and BY color difference signals are demodulated, and a built-in arithmetic circuit. The brightness signal Y is calculated and amplified by
Standard NTSC video signal, G video signal, B video signal
The color demodulator 70 demodulates.

In order to convert the standard three-primary-color video signals of standard scanning speed, which are simultaneously demodulated in parallel in RGB, into serial time-division RGB video signals compressed for ¼ time, three independent quantization numbers are used. Parallel 8-bit analog-digital converter (abbreviated as A / D converter hereinafter) 81R, 81G, 8
By 1B, it is converted into a digital three-primary-color video signal of standard scanning speed. The analog-digital conversion clock signal is
It is generated and supplied by a 3f _SC phase control synchronous oscillator 71 which triples the continuous reference color subcarrier f _SC .

The digital three-primary color video signal converted into the three primary colors in parallel is temporarily stored and stored in the three frame memory units 81R, 81G and 81B provided in parallel independently in the order of scanning time. Standard odd field three primary color video signals are odd field memory _{81R O,} 81G _O, 81B
_The standard even field 3 primary color video signal is temporarily stored in the even field memories 81 _RE , 81 _GK and 81 _BE .

The conversion reading for converting the 1/4 hour compression conversion and the RGB video signal in time division is performed by the R once stored and stored.
GB3 one of the odd field memory _81R O, 81
G _O, conducted from 81B _O, delayed by one standard speed field time from the time of storage, to the following standards even field time, the read clock reads at _{12f SC} is performed by increasing to four times the write clock _{3f SC.} Reading of the odd field memory and the even field memory is alternately repeated, and the quadruple speed clock is 3f.
Based on the _{SC, 12f SC} phase synchronously controlled oscillator 72
Generated and supplied by.

The generation and timing of the continuous pulse of the 1 / 4-hour compressed digital RGB time-division video signal from the frame memory temporarily stored are synchronized with the rising phase of the standard vertical synchronizing signal f _V and tripled. The rising phase of the triple speed vertical synchronization signal 3f _V is used as a starting point, and steering control is performed by a ternary ring counter 76 described later,
RG is divided into 3 equal parts of the standard 1 field time.
Frame memory 81R, 81 temporarily stored in sequence B
The data is read from the G and 81B at 12 f _SC clock.

Three frame memories 8 to be read
1R, 81G, and 81B, each of which has the same quantization terminal of 8 outputs, is connected in parallel, and is connected to the subsequent one digital-analog converter 83 to the same quantization input terminal of 8 bits. It is converted into a 4-hour compression time-division RGB video signal, further analog-complemented by a low pass filter 84 in the next stage, and via a polarity inversion video amplifier 85.
It is supplied and driven to the video input terminal of the high-speed responsive monochrome LCD. The standard odd-numbered and even-field three-primary-color video signals are alternately repeated by repeating the above-described conversion process.

The generation circuit and control of various timing pulses necessary for the above-mentioned 1/4 time compression time division RGB video signal conversion will be described with reference to FIG. The composite luminance video signal Y from which the color subcarrier component has been removed from the output of the Y-C separation circuit 62 is input to the sync separation circuit 63, and the standard composite sync signal obtained by slicing and amplifying the composite sync portion is output to the sync separation circuit 63. Get first from The vertical synchronizing signal obtained by integrating and separating this by the integrating circuit 65 is input to the vertical pulse amplifier 67, and the standard vertical synchronizing signal pulse f _V is obtained from the output thereof. Further, the horizontal synchronizing signal differentiated and separated by the differentiating circuit 64 is amplified and added to the horizontal phase control synchronizing oscillator 65 to obtain the standard horizontal synchronizing signal pulse f _{H from} which the equivalent pulse has been removed. Based on the standard sync signal generated by the same process as standard TV,
Various timing pulses are produced for the quarter time compression conversion, as described below.

The generation of a standard odd and even field determination signal, as usually carried out, from the rise of the standard vertical synchronizing signal pulses, about 10H (635μS) odd-even of 60H _Z pulse width of about 20μS delayed A field determination window pulse is generated every field by an odd / even discrimination window signal pulse generator 68 in which two monostable multivibrators are connected in cascade. The output and the output f _H of the standard horizontal phase control oscillator 65 from which the equivalent pulse is removed are set to 2
In addition to the input logical product circuit 69, the judgment is made based on the presence / absence of the AND gate output. It can be determined from the 2: 1 interlace relationship of standard television that the odd field is present when present and the even field when not present. The odd and even field determination signal, since the horizontal sync signal pulse of the pulse width 10μS of 30H _Z is output, the standard vertical synchronizing pulse f
_V is input to the set terminal of a flip-flop (FF) 73 that operates as a clock input, forcibly converting the odd field to a logical H level and the even field to a rectangular wave with a 50% duty specified as a logical L level. Then, it is supplied as a write steering control signal of the odd / even field memory of the frame memory and a drive input signal of the optical interlace scanning optical deflector.

Generation of a steering control signal for time-division RGB sequential reading of three field memories of RGB provided in each odd / even field of a standard television. 60H
_Z and rising phase the leading edge of the standard vertical synchronizing signal pulses f _V of, and feedback control by comparing the leading edge rising phase of the output of the 3f _v phase locked oscillator 74 of 180H _Z,
Frequency and, firstly to generate a consistent and accurate 3-speed vertical synchronizing signal pulses 3f _v phase, the 3-speed vertical synchronizing signal pulses 3f _V, 3 pieces of JK · flip-flop (F ·
F) RGB ternary ring counter circuit 7 composed of circuits
Input to each clock terminal of 6. Further, in order to forcibly determine the reading order of RGB, the standard vertical synchronizing signal f _V is set to the set terminal of R (F · F) by G
In addition to the reset terminal of (F ・ F), the reset terminal of B (F ・ F). The initial conditions are determined by forcibly setting [Q _R = H, Q _G = L, Q _B = L] for the Q outputs of the three F · Fs with the standard vertical synchronization signal f _V , and the following 2 In synchronization with the rising of the clock of the third triple speed vertical synchronization signal 3f _V ,
The H level of the three F · Fs is shifted by one stage, and [Q _R = L,
Q _G = H, Q _B = L], and the next third 3f
_At the rising edge of the _V clock, [Q _R = L, Q _G = L, Q
Changes to _B = H], further comprising a repeat _{[Q R = H, Q G} = L, Q B = L] , and the operation to return to the initial state at the rising edge of the fourth 3f _V clock. The output of the RGB ternary ring counter 76 is repeatedly circulated in the order of H level QR _R , Q _G , and Q _B in the odd and even fields, and is shown in FIGS. The waveform is obtained. This signal is supplied as a control signal that determines the reading order and reading section of the 1/4 hour compression conversion RGB frame memory (81R81G81B) and a color change timing control signal of the electrical three primary color modulator.

The timing pulse signals necessary for driving the monochrome LCD by converting it into a 1/4 hour compressed RGB time-division video signal are the start timing of the LCD horizontal scanning shift register 12 and the shift of the LCD vertical scanning shift register 4. The 4 × horizontal synchronizing signal 4f _H used as a clock and the 3 × vertical synchronizing signal 3f for the start timing of the LCD vertical scanning shift register 13
_V. The 4 × speed horizontal synchronizing signal 4f _H is generated and supplied by a 4f _H phase control synchronizing oscillator 75 which is controlled to coincide with the rising phase of the standard horizontal synchronizing signal f _H and oscillates synchronously.

In an example in which the number of horizontal pixels of the LCD section is 480 points, in the effective video signal time (13.3 μS) in one primary color horizontal scanning time compressed for ¼ hour, 480 points (sample frequency) about 32.2MH _Z) video sampling points are provided, the horizontal shift register 12 of 480 bits corresponding is provided. Based on the rising phase of the 4x horizontal sync signal 4f _H , the phase control oscillator built in the LCD section is used to sample 32.2 MHz _Z
When a clock pulse is generated and a 480-bit shift register is driven, only one bit of the 480 bits becomes H level, and an image sampling pulse for each pixel is sequentially transferred from the first in synchronization with the sampling clock. . An effective image section in the horizontal scanning line that has been compressed and converted for 1/4 hour is sampled and held dot-sequentially at equal intervals of 480 points by the image sampling pulse in units of pixels, and an electric signal is provided for each 480 horizontal pixels. The data is temporarily stored in the capacitor in a dot-sequential manner and converted into a static DC video signal. Further, through the 480 sampling amplifiers provided for each horizontal pixel, they are collectively transferred in parallel to the 480 data lines of the LCD substrate during the next horizontal retrace time and supplied.

This operation is performed in a standard field time of 1/4 of 262.5 scanning lines similar to a standard television.
As a time-compressed RGB video signal, it is rewritten 480 for each scanning line for each of the three primary color fields.
Supplied on the data line of the book.

The vertical scanning of a 240 line LCD is 24
It is driven by providing a 0-bit vertical scanning shift register 13. Start timing of the vertical scanning, paddle uses the rising phase of the 3-speed vertical synchronizing signal 3f _V, clock after 4x horizontal synchronizing signal 4f _H waiting counted 20H content, to start the shift register 13 from 21H th The operation of stopping at the 260th H is repeated. Each output of all 240 bits is synchronized with the quadruple speed horizontal synchronizing signal, only one bit from the 1st bit to the 24th bit becomes H level, and is sequentially transferred from the first in synchronization with the clock signal. This vertical scan shift register 1
Outputs of all 240 bits of 3 are connected and supplied corresponding to 240 gate lines (horizontal direction) corresponding to 240 effective vertical scanning lines of the LCD.

The vertical 480 data lines of the black-and-white LCD and the horizontal 240 gate lines are insulated and orthogonally wired on the transparent glass substrate of the black-and-white LCD, and 480 × 240 thin films are formed at the intersections. A field effect transistor (hereinafter abbreviated as TFT) is integrated and arranged. TFT gate for the gate line and TF for the data line
Although the T train is connected and the TFT source is connected to the transparent pixel electrode individually and independently, the TFT portion is simply represented by a black dot, which is shown in FIG. 3 as a conceptual diagram of the LCD.

The 480 data lines are supplied with a video signal obtained by sampling and holding at 480 points an effective video signal portion for each horizontal scanning line of the R, G, B and 3 primary color fields, which is compressed for ¼ hour. The gate line 1
480 for one line when the line becomes H level
The pixel transistors are turned on at the same time and T
It is driven by being resampled and written in the pixel capacitance parasitic on the independent transparent electrodes of the 480 horizontal liquid crystal pixels connected to the source of the FT. This operation is sequentially written from the 21st line to the 260th line in the horizontal scanning order, and the display of the field image for one primary color is completed. This write operation is performed in the order of R, G, B in the standard 1 field time by 1/4 hour compression time division RGB video signal.
The entire surface D is divided into three primary color fields at equal time intervals and rewritten, and the color image display for one standard field is completed.

This operation is performed in the same manner by dividing it into a standard odd field and an even field and repeating them alternately. After providing a liquid crystal response time by providing a blank time each time writing of one primary color field is completed. Colorless transparent black and white LCD by irradiating the same primary color light with flash
A color image is displayed on. The light output response of the liquid crystal pixel is a time-integrated response corresponding to the hold voltage charged in the pixel capacitance and is the same as that of a normal liquid crystal image display panel, but the integrated response time after writing is 240 Since a time difference of several mS occurs in the second line, it is necessary to provide a blank time after writing and to use a high-speed liquid crystal response of about 1 mS or less in accordance with the shortest response time.

[0045]

The present invention is configured as described above and has the effects described below.

With a single black-and-white LCD having an arbitrary line configuration, image display with three times the color resolution of the conventional one can be displayed, and cost reduction and reduction in size and weight can be achieved.

In principle, there is no mismatch between the three primary color images, and RGB is displayed in white at the same location on one pixel in a time-sharing manner, so that the mosaic pattern of the three primary color pixels looks inconspicuous and natural.

With a 240 line LCD, interlaced image display faithful to 2: 1 interlacing of television broadcasting can be performed by combining an LCD having integrated pixels for one field and an optical deflector for complementing pixels between lines. Therefore, it is possible to effectively display an image with about twice the vertical line resolution.
Double color image display is possible.

Even with a 480-line LCD in which pixels of odd-numbered and even-numbered fields are integrated, a slight deterioration in vertical line resolution can be tolerated and a single LCD can display a time-division color image. We can provide products that take advantage of features such as non-registration, small size, light weight, and low cost.

A high quality color image display equivalent to 960 lines can be displayed by sharing one line 480 line LCD and line intermediate complement between odd and even fields by light deflection.

[Brief description of drawings]

FIG. 1 is a central cross-sectional view showing a configuration of an embodiment of a time-division flash illumination type liquid crystal projection type color image display device configured by one flash lamp.

2 is a 3 obtained by the electrically controlled 3 primary color modulator of FIG.
It is a primary color spectral transmission characteristic diagram.

FIG. 3 is a block circuit diagram of an electric circuit for driving the time division flash illumination type liquid crystal projection type color image display device of FIG.

FIG. 4 is a timing chart of output waveforms of respective parts of the electric circuit block diagram of FIG.

FIG. 5 is an explanatory diagram of an electric circuit of a flash lamp and light emission timing.

FIG. 6 is a central cross-sectional view showing an embodiment of a time-division flash illumination type liquid crystal projection color image display device composed of three flash lamps.

7 is a spectral transmission characteristic diagram of three primary color lights obtained by the three primary color separation cross dichroic mirror shown in FIG.

[Explanation of reference signs] Liquid crystal image display panel (LCD) Electric control 3 Primary color modulator section Flash lamp section Projection lens section Light deflector section 11 Black and white LCD 12 Horizontal scanning shift register / sample holder 13 Vertical scanning shift register 21 Electro-optics Materials (PLZT) 21 _e Ground electrode 21 _d Drive electrode 22 Glass substrate 23 Deflection plate (polarizer) 24 Plastic / optical retarder 25 Field lens 26 Deflection plate (analyzer) 27 B Reflective dichroic mirror (B DM) 28 R reflection dichroic mirror (R / DM) 31 reflector 32 visible band filter 51 white reflection mirror 52 leaf spring disk 54 cylindrical permanent magnet 56 soft magnetic iron plate cylindrical magnetic path 57 excitation coil 58 transient vibration absorption rubber damper 59 spacer 61 Buffer image amplifier 62 Y C separation circuit 63 sync separator 64 horizontal synchronization generator circuit 65 the horizontal phase-locked oscillator 66 vertical sync generator 67 vertical pulse amplifier 68 even-odd discrimination window pulse generator 69 a logic AND circuit 70 standard RGB color demodulator 71 3f _SC phase synchronization Oscillator 72 12f _SC Phase-locked oscillator 73 Even / odd discrimination F / F output circuit 74 3f _V Phase-locked oscillator 75 4f _HD Phase-locked oscillator 76 Tertiary ring counter 80 Low-pass filter 81 A / D converter (R, G) , B) 82 Frame memory (R, G, B) 83 D / A converter 84 Low-pass filter 85 Polarity inversion amplifier 86 Polarity inversion F / F (a) standard Television color composite video signal (b) standard R video signal (c) Standard G video signal (d) Standard B video signal (e) Odd / even field discrimination output Signal (f) standard vertical synchronizing signal _f V (g) 3-speed vertical synchronizing signal _3f V (h) when R · division time division reference signal (i) G · time division time division reference signal (j) B · time division time Classification reference signal (k) 1/4 hour compression / time division RGB video signal (l) Flash illumination timing D ₁ , D ₂ DC power supply diodes C _d1 , C _d2 DC power supply capacitor C _T trigger capacitor C _{F For} heavy discharge Capacitor R _S Power supply overcurrent limiting resistor R ₁ , R ₂ voltage dividing resistor R _Y Charging current suppressing resistor R _G Gate grounding resistor T _T Trigger transformer T _R MOS · Power transistor

[Procedure amendment]

[Submission date] March 30, 1994

[Procedure Amendment 1]

[Document name to be corrected] Drawing

[Correction target item name] All drawings

[Correction method] Change

[Correction content]

[Figure 1]

[Fig. 2]

[Figure 5]

[Figure 6]

[Figure 7]

[Figure 3]

[Figure 4]

Claims (4)

[Claims] 1. A red, green and blue primary color video signal is about 60H.
_The three primary color video signals of the television transmitted simultaneously in parallel in the _Z field time unit are simultaneously converted into digital video signals of the three primary colors independently in parallel, and digital signals are provided independently in red, green, blue and parallel. After temporarily storing in the field memory, red at the time interval that divides the field time into three equal parts,
Time-sharing RG that is compressed in time for green and blue in order of less than 1/3
Scanning time is converted into B video signal and read out, digital-analog conversion is performed according to the reading order, and time-compressed three primary color video signals are written and displayed on the monochrome liquid crystal image display panel. At the end of writing for each primary color video signal, Provide a means for generating a vacant time until the start of writing the next primary color signal, and illuminating the same primary color light corresponding to the primary color video signal for which writing has been completed in a time division plane sequential intermittent flashing manner in the latter half of the vacant time. A three-primary time-division flash lighting type liquid crystal projection type color image display device. 2. The black and white liquid crystal image display panel according to claim 1, wherein the means for illuminating the three primary color intermittent flashes is provided with one white flash lamp and an electrically controlled three primary color modulator, and R,
A three-primary time-division flash illumination type liquid crystal projection type color image display device which is configured to be decomposed into G and B primary color lights and selectively transmit R, G and B primary color lights in a time division manner. 3. The black-and-white liquid crystal image display panel according to claim 1, wherein the three primary color intermittent flash light illuminating means is used for separating the three primary colors.
A 5 degree cross dichroic mirror and 3 flash lamps are provided, and the lights are cyclically lit in a time-sharing manner, and the R, G, and B primary color lights are selected in a time-sharing manner and illuminated. Liquid crystal projection type color image display device. 4. A black-and-white liquid crystal display panel having a number of pixels for one field, which is about half the number of vertical effective scanning lines, and a projection lens for enlarging and projecting the same, to a half of the vertical pixel pitch size. An optical deflector that shifts to a corresponding binary value is provided, and the middle of the line pixels of the odd field display image and the even field display image is complemented by driving the optical deflector temporally and spatially, and visually doubling. 3 primary color time division flash illumination type liquid crystal projection type color image, characterized in that it is provided with means for projecting and displaying a television image which is interlaced and scanned by the number of lines and displaying with high vertical resolution corresponding to 2: 1 interlace Display device.