JP2006071930A - Image display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image display device capable of suppressing the occurrence of an afterimage phenomenon accompanying power supply shutdown. <P>SOLUTION: The image display device comprises a display part main body 441 having signal lines 441H, scanning lines 441V and display pixels, a display control system 62 which controls the drive of the respective display pixels in accordance with image information and a power supply means 5 which supplies a power to the display part main body 441 and the display control system 62. Among them, the power supply means 5 includes a power source shutdown detection part which outputs a power source shutdown signal to the display control system 62 upon the power supply shutdown and a power retaining part which retains a part of the power from an external power source and supplies the power retained upon the power supply shutdown to the display control system and the display part main body. Further, the the display control system 62 includes a charge uniformizing means which, when the power source shutdown signal is input, uniformizes the charge accumulated in the respective display pixels of the display part main body by the power of the power retaining part. As the result, the remaining of charge according to image information in the display part main body can be suppressed. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an image display device. Specifically, a plurality of signal lines arranged substantially parallel to each other on the substrate, and a plurality of scans arranged in a direction substantially orthogonal to the arrangement direction of the plurality of signal lines so as to intersect each of the plurality of signal lines. And a display unit main body including a plurality of display pixels connected to the respective signal lines and scanning lines, and via the plurality of signal lines and the plurality of scanning lines according to input image information. The present invention also relates to an image display apparatus comprising: a display control system that drives and controls each display pixel; and a power supply unit that supplies power to the display unit main body and the display control system.

  Conventionally, projectors are used for presentations at conferences, academic conferences, exhibitions, and the like. Such a projector includes a light source, a light modulation element that modulates a light beam emitted from the light source according to image information to form an optical image, and a projection that enlarges and projects the optical image formed by the light modulation element. It is configured with a lens.

  In such a projector, a TFT type active matrix liquid crystal panel may be used as a light modulation element. Such a liquid crystal panel includes a pair of transparent substrates and a liquid crystal material hermetically sealed between the pair of substrates. Among these, a plurality of scanning lines and a plurality of signal lines extending in directions orthogonal to each other are formed on the substrate, and pixel electrodes are respectively formed in rectangular regions surrounded by the respective scanning lines and signal lines, This is a display pixel. Each display pixel is connected to a scanning line and a signal line surrounding the display pixel via a TFT (Thin Film Transistor) or a TFD (Thin Film Diode), and is displayed via the scanning line and the signal line. When a voltage is applied to the pixel, the orientation of the liquid crystal material in the display pixel changes according to the voltage, and the transmittance of incident light changes.

  When such a liquid crystal panel is displaying a predetermined image, when the power switch of the projector is turned off, the charge based on the signal written to each display pixel remains as it is, and the power switch is turned on again. When the projector is activated, there is a problem that an afterimage phenomenon occurs due to the previous residual charge. If such a state is repeated, an abnormal voltage due to residual charge may adversely affect the life of the pixel electrode.

  For such a problem, a control unit provided in the apparatus main body detects that the power button has been turned off by the user, and the control unit outputs a power-off signal to each display pixel of the liquid crystal panel. A projector that applies a predetermined voltage is known (see, for example, Patent Document 1). In this projector, a normally white liquid crystal panel is employed, and when the power switch is turned off, each display pixel of the liquid crystal panel is displayed in white to prevent an afterimage phenomenon.

JP 2003-173172 A

However, the projector described in Patent Document 1 cannot remove the residual charge of the display pixel when the connection with the external commercial power supply is disconnected or when the power supply is suddenly cut off during a power failure. There is. That is, since the residual charge is removed only when the power switch is turned off by the user, there is a problem that it is impossible to cope with the case where the power supply is suddenly cut off.
Particularly in recent projectors, a configuration is adopted in which a transmissive region in each display pixel is enlarged in order to improve the utilization factor of light from a light source and improve the luminance of a projected image. For this reason, since the liquid crystal material portion of each display pixel is enlarged and a large amount of voltage based on the video signal is applied, the voltage applied to the pixel electrode tends to remain, and the afterimage phenomenon caused thereby is remarkable. It was cited as a problem.

  The objective of this invention is providing the image display apparatus which can suppress generation | occurrence | production of the afterimage phenomenon accompanying sudden power supply interruption | blocking, such as a power failure.

  In order to achieve the above object, an image display device according to the present invention includes a plurality of signal lines arranged substantially parallel to each other on a substrate, and an arrangement of the plurality of signal lines so as to intersect with each of the plurality of signal lines. A plurality of scanning lines arranged in a direction substantially orthogonal to the direction, and a display unit body including a plurality of display pixels connected to the respective signal lines and scanning lines, and depending on input image information, An image including a display control system that drives and controls each of the display pixels via a plurality of signal lines and the plurality of scanning lines, and a power supply unit that supplies power to the display unit main body and the display control system. In the display device, the power supply means monitors a power supply state from an external power source, and outputs a power cutoff signal to the display control system when the power supply is cut off, and is supplied from the external power source. The A power holding unit that holds a part of the power and supplies the power held when the power supply is cut off to the display control system and the display unit body, and the display control system receives the power cut-off signal And charge equalization processing means for equalizing charges accumulated in each display pixel of the display unit main body based on the power supplied from the power holding unit.

  According to the present invention, the power cutoff detection unit detects the cutoff of the power supply from the external power source, and outputs a power cutoff signal to the display control system for driving and controlling the liquid crystal panel. The electric charge accumulated in each display pixel of the display unit main body is made uniform by using the electric power held in the electric power holding unit. According to this, even when the power supply is suddenly cut off due to a power failure or the like, the charge accumulated in the display unit main body can be made uniform, so that when the power supply is restored, the residual image causes an afterimage of the projected image. It is possible to prevent the phenomenon from occurring. Therefore, even in the case of sudden power supply interruption, the charge of the display unit body can be made uniform and the afterimage phenomenon can be prevented.

In the present invention, the power supply means includes a primary side power supply system that converts an alternating current input from the external power source into a direct current, and a secondary that converts the voltage of the power converted into the direct current into a predetermined voltage. It is preferable that the power holding unit is a circuit element constituting the primary power supply system.
Here, the power holding unit can be configured by a capacitor having a large holding capacity, for example.
According to the present invention, the primary power supply system includes a power holding unit that holds part of the power supplied from the external power supply. Here, the primary power supply system rectifies an alternating current and converts it into a direct current, but the current immediately after the alternating current is rectified is a pulsating current. In order to convert this pulsating current into a stable DC current, it is necessary to smooth the power using a capacitor or the like for storing and discharging electric power. By increasing the power holding capacity of this capacitor, stable DC current conversion can be achieved, and when the power supply from the external power supply is cut off as the power holding unit, the drive power is supplied to the display unit body and the display control system. Can be supplied. Therefore, it is not necessary to separately provide a power holding unit, and the power holding unit can be configured even in a general-purpose power supply unit by increasing the holding capacity of the capacitor.

In the present invention, the power supply means is electrically connected to a light source that illuminates the display unit main body, and when the power supply means detects that the power supply is cut off by the power cut-off detection unit, the light source It is preferable to include power regulation means for regulating power supply to the vehicle.
According to the present invention, when power supply from the outside is interrupted, that is, when power supply interruption is detected by the power interruption detection unit, the power supply to the light source is regulated by the power regulating means. The finite power held in the power holding unit can be prevented from being consumed by the light source having a large power consumption. That is, the power held in the power holding unit can be reliably supplied to the display unit main body and the display control system. Accordingly, it is possible to secure the drive power of the display unit body and the display control system when the power supply is cut off, and to reliably perform the charge equalization process of the display unit body by the charge equalization processing unit.
In addition, since the image display device is provided with a light source that illuminates the display unit main body, an optical image formed by the display unit main body can be projected clearly.

In the present invention, it is preferable that the display control system includes a start adjustment unit for timing the power supply regulation by the light source power regulation unit and the homogenization process by the charge equalization processing unit.
According to the present invention, the electric power held in the electric power holding unit is effectively used by the timing of the electric power supply restriction by the electric power restriction means and the equalization process by the electric charge equalization processing means by the start adjustment means. be able to. In other words, after the power supply to the light source is regulated, the power used in the process can be secured by executing the process that increases the power consumption in the charge equalization process. Can be completed without fail.

In the present invention, an image control unit that performs image output control based on input image information is provided, and the charge equalization processing unit outputs a signal for displaying a monochromatic image on the display unit body to the image control unit. Then, it is preferable to perform the homogenization treatment.
According to the present invention, when the charge equalization processing unit outputs a signal for displaying a single color image on the image control unit, the display unit main body controlled by the image control unit has a voltage for displaying the single color image. Will join. Thereby, since a uniform charge is applied to each display pixel constituting the display unit main body, an afterimage phenomenon of an image can be suppressed.

Alternatively, in the present invention, the display control system is provided on the input side of each of the scanning lines, and a scanning line side driving circuit including a shift register that sets each of the scanning lines to a two-level voltage application state; Each of the signal lines includes a signal line side driving circuit having a two-level voltage application state and another shift register provided on the input side of each of the signal lines. It is preferable to perform the charge equalization process by aligning the voltage application state of one of the shift registers of the scanning line side driving circuit and the signal line side driving circuit.
Here, the shift register provided in the scanning line side driving circuit and the signal line side driving circuit holds a synchronization signal or a video signal based on the image signal in a plurality of registers, shifts each register at a predetermined timing, Based on the synchronization signal and the video signal held in the register, a driving signal for the liquid crystal panel is output to the scanning line or the signal line. The scanning line to which the drive signal is output from the shift register is in a selected state, and an image is formed by inputting a video signal to the display pixel connected to the scanning line through the signal line. Since the voltage application state of the shift register of either the scanning line side drive circuit or the signal line side drive circuit is aligned by the charge equalization processing means of the present invention, a uniform voltage is applied to each register. Thus, it is possible to prevent the charge based on the image information from remaining in the shift register by releasing the charge of each register. Accordingly, the charge held in the shift register can be made uniform so that the charge based on the image information applied from the shift register to the display unit main body does not remain in the shift register and the display unit main body. The afterimage phenomenon of the subsequent image can be suppressed.

In the present invention, the display unit body is configured as a normally white type or a normally black type, and the charge equalization processing means displays white when the display unit body is a normally white type. In the case of a normally black type by applying a voltage, it is preferable to apply a voltage for displaying black.
Here, the normally white type display unit body displays white with the maximum light transmittance when the level of the applied voltage is low. In addition, the normally black display main body displays black with a minimum light transmittance when the applied voltage level is low.
According to the present invention, the charge equalization processing means applies a voltage for displaying white on a normally white display unit body and a voltage for displaying black on a normally black display unit body. Therefore, it is possible to release a charge remaining on the display unit body by applying a low level uniform charge to the display unit body. Therefore, the voltage applied to the display unit main body can be set to the minimum voltage, so that the afterimage phenomenon of the image can be further suppressed.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
(1) External Configuration FIG. 1 is a perspective view of a projector 1 according to the present embodiment as viewed from the upper front side. FIG. 2 is a perspective view of the projector 1 as viewed from the lower front side. FIG. 3 is a perspective view of the projector 1 as viewed from the upper back side.
The projector 1 as an image display device modulates a light beam emitted from a light source in accordance with image information, and enlarges and projects it on a projection surface such as a screen. As shown in FIGS. 1 to 3, the projector 1 includes a substantially rectangular parallelepiped outer case 2 and a projection lens 3 exposed from the outer case 2.
Among these, the projection lens 3 has a function as a projection optical system for enlarging and projecting an optical image modulated and formed by a liquid crystal panel 441 (see FIG. 5) as a display unit body to be described later. The lens holding cylinder 3A is configured as a combined lens in which a plurality of lenses are housed.

The outer case 2 is a synthetic resin casing having a substantially rectangular shape in plan view, and houses an apparatus main body including an optical unit 4 described later of the projector 1. The outer case 2 includes an upper case 21 covering the upper surface portion of the apparatus main body, a lower case 22 covering the lower surface portion of the apparatus main body, a front case 23 covering the front surface portion of the apparatus main body, and a part of a side surface portion of the apparatus main body. And a rear case 25 (see FIG. 3) covering the back portion of the apparatus main body.
Note that the corners of the top surface, front surface, side surface, bottom surface, and back surface of the exterior case 2 are formed in a curved surface.

The upper case 21 includes an upper surface portion 21A having a substantially rectangular shape that covers the upper surface portion of the apparatus main body, a side surface portion 21B that substantially hangs down from one end portion in the long side direction of the upper surface portion 21A, and a long side of the upper surface portion 21A. A side surface portion 21C that substantially hangs down from the front portion of the other end portion in the direction and a back surface portion 21D (see FIG. 3) that hangs down substantially from the rear end portion of the upper surface portion 21A.
As shown in FIGS. 1 and 3, an operation panel 26 that performs startup / adjustment operation of the projector 1 is provided at a substantially central portion on the back side of the upper surface portion 21 </ b> A so as to extend in the horizontal direction. The operation panel 26 is provided with a plurality of operation switches 261 including a power switch. When these operation switches 261 are appropriately pressed, they contact a tact switch mounted on a circuit board (not shown) disposed inside the operation panel 26. The desired operation becomes possible. In addition, an LED (not shown) is attached to the circuit board so as to emit light according to a desired operation.
Furthermore, the operation panel 26 includes a decorative plate 262 disposed so as to surround the operation switch 261, and light from the LED is diffused through the decorative plate 262.

Further, from the front side (the right side in FIG. 1) of the upper surface portion 21A, two dials constituting a projection lens position adjusting mechanism (not shown) for adjusting the position of the projection lens 3 by moving the projection lens 3 up and down and left and right. 311 and 321 are exposed.
When the dial 311 arranged on the left side in FIG. 1 is moved in the Y1 direction (downward), the projection lens 3 moves in the Y3 direction (downward) and the dial 311 moves in the Y2 direction (upward). When the lens is moved to, the projection lens 3 moves in the Y4 direction (upward).
When the dial 321 arranged on the right side in FIG. 1 is moved in the X1 direction (rightward when viewed from the rear of the projector 1), the projection lens moves in the X3 direction (rightward), and the dial 321 is moved in the X2 direction (from the rear of the projector 1). When it is moved in the left direction as viewed, the projection lens 3 moves in the X4 direction (left direction).
Further, although not shown, a rib is provided on the inner surface side of the upper surface portion 21 </ b> A so as to surround the outer periphery of the projection lens 3.

The side surface portion 21 </ b> C is formed with a notch 21 </ b> C <b> 1 in which the louver 71 composed of a plurality of blades 711 is exposed.
Further, as shown in FIG. 3, the back surface portion 21D is formed with a notch 21D1 with which the rear case 25 is engaged.

The lower case 22 includes a bottom surface portion 22A, side surface portions 22B and 22C, a back surface portion 22D, and a front surface portion 22E, as shown in FIGS.
The bottom surface portion 22A has a substantially rectangular plane shape, and a fixed leg portion 22A1 is provided at the center of the bottom surface portion 22A on the back side of the projector 1 and adjustment leg portions 27 are provided at both ends in the long side direction on the front surface side. It has been.
The adjustment leg 27 includes a shaft-like member 271 (see FIG. 4) that protrudes forward and backward from the bottom surface 22 </ b> A so as to be able to move forward and backward. The inclination position of the direction can be adjusted.
In addition, an opening 22A3 that communicates with the inside of the exterior case 2 is formed in the bottom surface portion 22A. The opening 22A3 is an intake port for taking cooling air outside the outer case 2 into the outer case 2, and a cover 22A5 having a plurality of openings is attached to the opening 22A3.

The side surface portion 22B is erected from one end portion of the bottom surface portion 22A in the long side direction, and engages with the side surface portion 21B of the upper case 21 as shown in FIG. Configure the side.
The side surface 22B is formed with a recess 22B1 that is recessed toward the upper case 21. The recess 22B1 is used as a grip when the projector 1 is gripped.
As shown in FIG. 1, the side surface portion 22C is erected from the front side portion of the other end portion in the long side direction of the bottom surface portion 22A, and engages with the side surface portion 21C of the upper case 21, A part of the side surface of the outer case 2 is formed. The upper end of the side surface portion 22C is greatly cut, and the louver 71 is exposed from the notch 22C1. That is, an opening through which the louver 71 is exposed is formed by the notch 21C1 of the side surface portion 21C and the notch 22C1 of the side surface portion 22C. Air that has cooled the inside of the projector 1 is discharged from the opening.

As shown in FIG. 3, the back surface portion 22D is erected from one end portion in the short side direction of the bottom surface portion 22A, and the back surface portion 22D has a notch 22D1 with which the rear case 25 is engaged. Is formed. In other words, in the present embodiment, the rear portions 21D and 22D and the rear case 25 constitute the rear surface of the outer case 2.
A rectangular opening 22D2 is formed in the back surface portion 22D, and the inlet connector 22D3 is exposed from the opening 22D2. The inlet connector 22D3 is a terminal that supplies power to the projector 1 from an external power supply, and is electrically connected to the power supply unit 5 described later.
Again, as shown in FIG. 1, the front surface portion 22E is erected from the other end portion in the short side direction of the bottom surface portion 22A. The front surface portion 22E engages with the front case 23, and these constitute the front surface of the exterior case 2.

As shown in FIGS. 1 and 2, the front case 23 has a substantially elliptical shape, and an opening 231 for exposing the projection lens 3 is formed on the end portion in the longitudinal direction (right side in FIG. 1).
In addition, a remote control light receiving window 232 is formed at a substantially central portion of the front case 23. Inside the remote control light receiving window 232, a remote control light receiving unit 233 that receives an operation signal from a remote controller (not shown) is exposed.
The remote controller is provided with the same switch as the operation switch 261 provided on the operation panel 26 described above. When the remote controller is operated, an infrared signal corresponding to the operation is output from the remote controller. The signal is received by the remote control light receiving unit 233 through the remote control light receiving window 232, converted into a control signal, and then processed by the control board 6 described later.

As shown in FIGS. 1 and 3, the side case 24 includes an upper surface portion 24A and a side surface portion 24C that is substantially suspended from the upper surface portion 24A. The upper surface portion 24 </ b> A is engaged with the upper surface portion 21 </ b> A of the upper case 21 to constitute the upper surface of the exterior case 2.
The side surface portion 24 </ b> C engages with the side surface portion 21 </ b> C of the upper case 21 and the side surface portion 22 </ b> C of the lower case 22.

As shown in FIG. 3, the rear case 25 is fitted and fixed in an opening formed by a notch 21D1 of the back surface portion 21D of the upper case 21 and a notch 22D1 of the back surface portion 22D of the lower case 22.
The rear case 25 has a substantially rectangular plane shape, and a remote control light receiving window 232 similar to that of the front case 23 is formed in the vicinity of the end in the longitudinal direction.
The rear case 25 is formed with a recess 251 that is recessed toward the inside of the exterior case 2, and a plurality of connection terminals 252 are exposed from the recess 251.
The connection terminal 252 is used to input image signals, audio signals, and the like from an external electronic device. The connection terminal 252 is connected to an interface board (not shown) located inside the rear case 25. Yes.
The interface board is electrically connected to a control board 6 described later, and a signal processed by the interface board is output to the control board 6.

(2) Internal Configuration FIG. 4 is a diagram showing an internal configuration of the projector 1. Specifically, only the lower case 22 of the outer case 2 is left, and the upper case 21, the front case 23, the side case 24, and the rear case 25 are removed.
Inside the exterior case 2 is housed an apparatus main body of the projector 1, and the apparatus main body includes an optical unit 4 extending in the left-right direction along the longitudinal direction of the exterior case 2, a power supply unit 5, and an optical unit 4. And a control board 6 as a control means disposed above.

(3) Structure of Optical Unit 4 FIG. 5 is a schematic diagram showing the configuration of the optical unit 4.
The optical unit 4 modulates the light beam emitted from the light source device according to image information to form an optical image, and forms a projection image on a projection surface such as a screen via the projection lens 3. As shown in FIG. 5, the optical unit 4 includes an integrator illumination optical system 41, a color separation optical system 42, a relay optical system 43, an optical device 44 in which a light modulation device and a color synthesis optical device are integrated, These optical components 41, 42, 43, and 44 are functionally broadly divided into optical component casings (not shown) that house and arrange them.

  The integrator illumination optical system 41 is an optical system for making the luminous flux emitted from the light source uniform in the illumination optical axis orthogonal plane. The integrator illumination optical system 41 includes a light source device 411, a first lens array 412, a second lens array 413, a polarization conversion element 414, and a superimposing lens 415.

The light source device 411 includes a light source lamp 411A as a radiation light source, a reflector 411B, and an explosion-proof glass 411C that covers a light beam emission surface of the reflector 411B. Then, the radial light beam emitted from the light source lamp 411A is reflected by the reflector 411B to become a substantially parallel light beam, and is emitted to the outside.
In the present embodiment, a high-pressure mercury lamp is used as the light source lamp 411A. However, the present invention is not limited to this, and for example, a metal halide lamp or a halogen lamp may be used. Moreover, although the parabolic mirror is employ | adopted as the reflector 411B, you may employ | adopt the structure which has arrange | positioned the collimating concave lens not only to this but to the output surface of the reflector which consists of an ellipsoidal mirror.

The first lens array 412 has a configuration in which small lenses having a substantially rectangular outline when viewed from the illumination optical axis direction are arranged in a matrix. Each small lens splits the light beam emitted from the light source lamp 411A into partial light beams and emits them in the direction of the illumination optical axis.
The second lens array 413 has substantially the same configuration as the first lens array 412, and includes a configuration in which small lenses are arranged in a matrix. The second lens array 413 has a function of forming an image of each small lens of the first lens array 412 on liquid crystal panels 441R, 441G, and 441B described later of the optical device 44 together with the superimposing lens 415.

The polarization conversion element 414 converts the light from the second lens array 413 into approximately one type of polarized light, thereby improving the light use efficiency in the optical device 44.
Specifically, each partial light beam converted into approximately one kind of polarized light by the polarization conversion element 414 is finally substantially superimposed on liquid crystal panels 441R, 441G, 441B, which will be described later, of the optical device 44 by the superimposing lens 415. . In a projector using liquid crystal panels 441R, 441G, and 441B of a type that modulates polarized light, only one type of polarized light can be used, and therefore approximately half of the light flux from the light source lamp 411A that emits randomly polarized light is not used. For this reason, the use efficiency of light in the optical device 44 is enhanced by converting the light beam emitted from the light source lamp 411A into substantially one type of polarized light using the polarization conversion element 414. Such a polarization conversion element 414 is introduced in, for example, Japanese Patent Application Laid-Open No. 8-304739.

The color separation optical system 42 includes two dichroic mirrors 421 and 422 and a reflection mirror 423. A plurality of partial light beams emitted from the integrator illumination optical system 41 are separated into three color lights of red (R), green (G), and blue (B) by two dichroic mirrors 421 and 422.
The relay optical system 43 includes an incident side lens 431, a pair of relay lenses 433, and reflection mirrors 432 and 435. The relay optical system 43 has a function of guiding blue light, which is color light separated by the color separation optical system 42, to a liquid crystal panel 441B described later of the optical device 44.

  At this time, in the dichroic mirror 421 of the color separation optical system 42, among the light beams emitted from the integrator illumination optical system 41, the green light component and the blue light component are transmitted, and the red light component is reflected. The red light reflected by the dichroic mirror 421 is reflected by the reflection mirror 423, passes through the field lens 419, and reaches the red liquid crystal panel 441R. The field lens 419 converts each partial light beam emitted from the second lens array 413 into a light beam parallel to the central axis (principal ray). The same applies to the field lens 419 provided on the light incident side of the other liquid crystal panels 441G and 441B.

Of the blue light and green light transmitted through the dichroic mirror 421, the green light is reflected by the dichroic mirror 422, passes through the field lens 419, and reaches the liquid crystal panel 441G for green light. On the other hand, the blue light passes through the dichroic mirror 422, passes through the relay optical system 43, passes through the field lens 419, and reaches the blue light liquid crystal panel 441B.
Note that the relay optical system 43 is used for blue light because the optical path length of the blue light is longer than the optical path lengths of the other color lights, thereby preventing a decrease in light use efficiency due to light divergence or the like. It is to do. That is, this is to transmit the partial light beam incident on the incident side lens 431 to the field lens 419 as it is. The relay optical system 43 is configured to pass blue light of the three color lights, but is not limited thereto, and may be configured to pass red light, for example.

  The optical device 44 modulates an incident light beam according to image information to form a color image. The optical device 44 includes three incident-side polarizing plates 442 on which the respective color lights separated by the color separation optical system 42 are incident, and a liquid crystal panel 441 as a light modulation device disposed at the subsequent stage of the incident-side polarizing plate 442. (441R, 441G, 441B), an exit-side polarizing plate 444, and a cross dichroic prism 445 as a color synthesizing optical device.

  The liquid crystal panels 441 (441R, 441G, 441B) are configured as the display unit main body of the present invention. Specifically, the liquid crystal panel 441 includes a plurality of signal lines arranged substantially parallel to each other on the substrate, a plurality of scanning lines arranged orthogonal to each of the plurality of signal lines, and the respective signals. A plurality of pixel electrodes arranged in the vicinity of the lines and the scanning lines and connected to the signal lines via the switching elements, a common electrode arranged opposite to the plurality of pixel electrodes, and the respective pixel electrodes and common electrodes And a plurality of liquid crystal materials that are filled and held in between. As such a liquid crystal panel, a normally white TFT liquid crystal panel using a polysilicon TFT as a switching element is employed in the present embodiment. The liquid crystal panels 441R, 441G, and 441B modulate and emit the light beam incident through the incident side polarizing plate 442 according to image information input through the scanning line and the signal line.

The incident side polarizing plate 442 transmits only polarized light in a certain direction out of each color light separated by the color separation optical system 42 and absorbs other light beams. A polarizing film is attached to a substrate such as sapphire glass. It has been done.
The exit side polarizing plate 444 is also configured in substantially the same manner as the incident side polarizing plate 442, and transmits only polarized light in a predetermined direction among the light beams emitted from the liquid crystal panels 441R, 441G, and 441B, and transmits the other light beams. The polarization axis of the polarized light that is absorbed and transmitted is set to be orthogonal to the polarization axis of the polarized light that is transmitted by the incident-side polarizing plate 442.

The cross dichroic prism 445 forms a color image by synthesizing optical images emitted from the emission-side polarizing plate 444 and modulated for each color light. In the cross dichroic prism 445, a dielectric multilayer film that reflects red light and a dielectric multilayer film that reflects blue light are provided in a substantially X shape along the interfaces of four right-angle prisms. Three color lights are synthesized by the dielectric multilayer film.
The liquid crystal panels 441R, 441G, 441B, the exit-side polarizing plate 444, and the cross dichroic prism 445 described above are integrally configured as a unit.

(4) Configuration of Power Supply Unit 5 FIG. 6 is a block diagram showing the overall configuration of the power supply unit 5 and a control board 6 described later. FIG. 7 is a block diagram showing a detailed configuration of the power supply unit 5.
As shown in FIGS. 6 and 7, the power supply unit 5 supplies power to the light source lamp 411 </ b> A of the light source device 411 and a control board 6 to be described later.
4, 6, and 7, the power supply unit 5 includes a power supply block 51 as power supply means and a lamp drive block 52 disposed below the power supply block 51 (not shown in FIG. 4). And a power regulating unit 53 (not shown in FIG. 4) that regulates the power supplied to the lamp driving block 52.
Moreover, the power supply unit 5 is arrange | positioned along the longitudinal direction of the front case 23 of the exterior case 2, as shown in FIG. Among these, the power supply block 51 is covered with a cylindrical member 5A as a shield member, and the cylindrical member 5A is made of aluminum and is formed in a substantially box shape with both ends opened.

  As shown in FIG. 4, an exhaust fan 72 is installed on the side of such a power supply unit 5, and air that has cooled the power supply unit 5 is discharged from an opening in which the louver 71 is attached. Yes. Further, a duct 73 is installed between the power supply unit 5 and the optical component casing (not shown), and the air that has cooled the light source device 411 is drawn by the exhaust fan 72, and the duct 73 is And is discharged from the opening.

(4-1) Configuration of the Power Supply Block 51 The power supply block 51 uses the power supplied from the external power supply to the electronic components such as the lamp drive block 52 and the control board 6 via the power cable connected to the inlet connector 22D3. Supply.
The power supply block 51 is divided into a primary power supply system 511 and a secondary power supply system 512, as shown in FIGS.

As illustrated in FIG. 7, the primary power supply system 511 includes a power supply monitoring unit 5111, a rectifier circuit 5112, a smoothing circuit 5113, and a booster circuit 5114 in the order in which the power supplied from the external power source flows. It is configured.
The power supply monitoring unit 5111 constitutes a power cutoff detection unit according to the present invention. The power supply monitoring unit 5111 monitors the supply state of power supplied from an external power source. A signal indicating that the power supply is cut off is output to a signal input unit 5122 constituting the supply system 512. Such a power supply monitoring unit 5111 can be configured by a light emitting element such as a photodiode. That is, the power supply monitoring unit 5111 outputs a signal to the signal input unit 5122 (described later) as a signal that light is emitted in the power supply state and not lighted in the power supply cutoff state.

The rectifier circuit 5112 generates a pulsating current from an alternating current of power supplied via the power supply monitoring unit 5111. Such a rectifier circuit 5112 can be configured by a diode bridge or the like configured by combining four diodes.
The smoothing circuit 5113 smoothes the pulsating current generated by the rectifying circuit 5112 into a direct current. Such a smoothing circuit 5113 includes a capacitor, and a stable direct current is supplied by the capacitor. In addition, this capacitor is a capacitor having a large power holding amount so that power can be supplied to the control board 6 and the like when the power supply from the external power source is cut off. The power holding unit 5113A of the invention is used. According to this, it is not necessary to separately provide an electronic component corresponding to the power holding unit 5113A in the power supply unit 5 which is a power supply unit. Therefore, it can be constituted by a general-purpose power supply unit, and the configuration of the power supply unit 5 can be simplified.
The booster circuit 5114 is composed of a transformer or the like, and boosts the voltage of the DC-converted current. A part of the power boosted through the booster circuit 5112 is supplied to the lamp drive block 52 via the power regulating unit 53 described later, and the other part is supplied to the transformer circuit 5121 of the secondary power supply system 512. The

The secondary power supply system 512 supplies the power supplied from the primary power supply system 511 to each electronic component constituting the projector 1. The secondary power supply system 512 includes a transformer circuit 5121, a signal input unit 5122, and a cutoff signal output unit 5123.
Among these, the transformer circuit 5121 transforms and supplies the voltage of the power supplied from the booster circuit 5114 of the primary-side power supply system 511 according to the electronic components constituting the projector 1.

The signal input unit 5122 and the cutoff signal output unit 5123 constitute the power cutoff detection unit of the present invention together with the power supply monitoring unit 5111 of the primary side power supply system 511.
Among these, the signal input unit 5122 receives a signal indicating that the power supply has been cut off from the power supply monitoring unit 5111 when the power supply is cut off. When this signal is input to the signal input unit 5122, the signal input unit 5122 outputs a predetermined signal to the cutoff signal output unit 5123.

  In the case where the power supply monitoring unit 5111 described above is configured by a light emitting element, the signal input unit 5122 can be configured by a light receiving element such as a phototransistor that receives light from the light emitting element. With the power supply monitoring unit 5111 configured with such a light emitting element, a change in the power supply state can be represented by a change in the light emission intensity of the light emitting element, and with the signal input unit 5122 configured with the light receiving element, A change in the power supply state can be detected by detecting the light emission intensity. Therefore, by configuring the power supply monitoring unit 5111 and the signal input unit 5122 with light emitting elements and light receiving elements, the power supply state can be detected quickly and with a simple configuration.

When the signal input from the signal input unit 5122 continues for a predetermined period, the cutoff signal output unit 5123 generates a power cutoff signal and power that mediates between the booster circuit 5114 of the primary power supply system 511 and the lamp drive block 52. The power cutoff signal is output to the regulation unit 53 and the charge equalization processing unit 622 constituting the display control system 62 of the control board 6 described later. In the present embodiment, the interruption signal output unit 5123 has a signal input duration from the signal input unit 5122 of 25 msec or more so that the interruption of one cycle or more of the alternating current supplied from the external commercial power supply can be detected. In addition, a power cutoff signal is generated and output. Thereby, the interruption signal output unit 5123 can prevent the instantaneous power failure from being regarded as a continuous power failure, and the projector 1 can be driven stably.
In the present embodiment, it is assumed that the power supply is interrupted when the signal input duration is 25 msec or more. However, the signal input duration for which it is considered that the power supply is continuously interrupted may be 25 msec or more. It may be set appropriately.

  Of these power supply monitoring unit 5111, signal input unit 5122 and cutoff signal output unit 5123, the power supply monitoring unit 5111 can detect the power supply state prior to current conversion in the primary power supply system 511. Further, the signal input unit 5122 and the cutoff signal output unit 5123 generate and output the power cutoff signal using the power supplied from the power holding unit 5113A when the power supply is cut off based on the signal from the power supply monitoring unit 5111. can do. Therefore, the power cutoff signal can be output to the power regulation unit 53 and the display control system 62 of the control board 6 quickly and reliably.

(4-2) Configuration of Lamp Drive Block 52 The lamp drive block 52 rectifies and transforms a direct current input from the power supply block 51 via the power regulating unit 53 to generate an alternating current rectangular wave current. The rectangular wave current is supplied to the light source lamp 411A of the light source device 411.
As shown in FIG. 7, the lamp drive block 52 includes a down converter 521, an inverter bridge 522, and an igniter 523 in the order in which the current supplied from the power supply block 51 flows.

  The down converter 521 removes high frequency noise and steps down the supplied direct current. Specifically, the DC voltage input at about 300 to 400 V is stepped down to about 50 to 150 V suitable for lighting the light source lamp 411A. Although not shown in detail, the down converter 521 includes a coil element and a diode that are connected in series, and a transistor and a capacitor that are branched and connected from these circuit elements.

  The inverter bridge 522 converts a direct current into an alternating current rectangular wave current. Although not shown in the figure, the inverter bridge 522 is configured as a bridge circuit including a pair of two transistors and a total of four transistors. The bridge circuit receives a direct current that has been stepped down through the down converter 521 and applies a pulse signal to each of the transistors. A path including one pair of transistors and a path including the other pair of transistors are provided. The current flows by short-circuiting alternately. Thereby, an alternating current rectangular wave current can be generated.

The igniter 523 is configured as a circuit that performs a dielectric breakdown between the electrodes of the light source lamp 411A and prompts the start of the light source lamp 411A.
Although not shown, the igniter 523 includes a high voltage pulse generation circuit and a pulse transformer connected to the primary side of the high voltage pulse generation circuit. The high voltage pulse generated by the high voltage pulse generation circuit is supplied to the pulse transformer. By boosting the voltage on the secondary side and applying the boosted power to the light source lamp 411A, the insulation between the electrodes of the light source lamp 411A is broken, electrical conduction is ensured, and the light source lamp 411A starts lighting.

  The down converter 521 and the inverter bridge 522 that constitute such a lamp drive block 52 are electrically connected to a light source drive controller 612 that constitutes a main control system 61 of the control board 6 described later. The main control system 61 outputs a voltage signal for determining the voltage level to the down converter 521, and outputs a pulse signal to the transistor of the inverter bridge 522. As a result, the voltage applied to the light source lamp 411A changes, and the light emission luminance of the light source lamp 411A is controlled.

(4-3) Configuration of Power Regulator 53 The power regulator 53 corresponds to the power regulator of the present invention, and includes a booster circuit 5114 that constitutes the primary power supply system 511 of the power supply block 51, and the lamp drive block 52. And relays the electric power supplied from the booster circuit 5114 to the lamp driving block 52. The power regulating unit 53 is electrically connected to a cutoff signal output unit 5123 that constitutes a power cutoff detection unit, and receives a power cutoff signal generated and output by the cutoff signal output unit 5123. Based on the input, power supply to the lamp drive block 52 is restricted.
Specifically, since the power cutoff signal is not input from the cutoff signal output unit 5123 in a state where the power supply is normally performed, the power regulation unit 53 uses the power supplied from the booster circuit 5114 as the lamp driving block 52. To supply. On the other hand, when the power supply is cut off, that is, when a power cut-off signal is input from the cut-off signal output unit 5123 to the power regulation unit 53, the power regulation unit 53 transmits the voltage from the booster circuit 5114 to the lamp drive block 52. Shut off the power supply. Accordingly, it is possible to prevent the finite power held in the power holding unit 5113A from being supplied to the lamp driving block 52 and consumed.

(5) Configuration of Control Board 6 The control board 6 is disposed above the optical unit 4 as shown in FIG. The control board 6 is configured as a circuit board on which an arithmetic processing device such as a CPU (Central Processing Unit) is mounted, and is a control means for controlling the entire projector 1.

FIG. 8 is a block diagram showing a detailed configuration of the control board 6.
As shown in FIGS. 6 and 8, the control board 6 includes a main control system 61 that performs drive control of the entire projector 1 and a liquid crystal panel 441 (441R, 441G, 441B) according to image information input from the outside. A display control system 62 for driving control and a memory 63 for reading / writing image display setting information such as a liquid crystal panel 441 by the display control system 62 are provided.
Of these, the memory 63 is configured by a flash memory in the present embodiment, but may be any recording medium that can be electrically read, written, and erased, and may be configured by an EEPROM or the like.

(5-1) Configuration of Main Control System 61 The main control system 61 includes a drive information output unit 611 and a light source drive control unit 612.
As shown in FIGS. 6 and 8, the drive information output unit 611 and the light source drive control unit 612 are based on the operation signals input from the operation switches 261 of the operation panel 26 and the remote control light receiving unit 233. The control signal is output as appropriate.
Among these, the drive information output unit 611 outputs the image display setting information of the liquid crystal panel 441 changed by the operation of the operation switch 261 and the remote controller by the user to the image control unit 623 of the display control system 62 described later. .
The light source drive control unit 612 outputs a control signal to the down converter 521 and the inverter bridge 522 of the lamp drive block 52 based on the luminance information of the light source lamp 411A according to the user's operation.

(5-2) Configuration of Display Control System 62 The display control system 62 is used to display image information input from the external connection device connected to the projector 1 through the interface board described above and the image display recorded in the memory 63. The liquid crystal panels 441R, 441G, 441B are driven and controlled based on the setting information.
As shown in FIG. 8, the display control system 62 includes an image conversion unit 621, a charge equalization processing unit 622, an image control unit 623, a scan driver 624, a signal driver 625, a start adjustment unit 626, A clock generation unit 627 and an information reading / writing unit 628 are provided.
Among them, the information reading / writing unit 628 reads the image display setting information stored in the memory 63 based on the control signal of the image control unit 623 or writes the image display setting information in the memory 63. save.

The image conversion unit 621 extracts a horizontal synchronization signal, a vertical synchronization signal, and a composite synchronization signal from image information input from the interface board, for example, a composite video signal. The image conversion unit 621 generates a horizontal synchronization signal, a vertical synchronization signal (also referred to as a synchronization signal) and a video signal in accordance with the specifications of the image control unit 623 based on the extracted signals. And output to the image control unit 623.
Note that the clock generator 627 generates a pulse signal having a predetermined frequency based on the synchronization signal.

  The charge equalization processing unit 622 corresponds to the charge equalization processing means of the present invention. The charge equalization processing unit 622 is electrically connected to the cutoff signal output unit 5123 of the secondary power supply system 512 that constitutes the power supply block 51 of the power supply unit 5. When the power cut-off signal is input to the charge equalization processing unit 622 from the cut-off signal output unit 5123, the charge equalization processing unit 622 first outputs an interrupt signal to the image control unit 623, Wait until there is a response signal from the image control unit 623. After receiving the response signal from the image control unit 623, the charge equalization processing unit 622 generates a new synchronization signal and video signal and outputs them to the image control unit 623.

In this embodiment, the synchronization signal and the video signal generated and output by the charge equalization processing unit 622 are a synchronization signal and a video signal for displaying a monochromatic image on the liquid crystal panel 441. Specifically, since the liquid crystal panel 441 is a normally white liquid crystal panel, a synchronization signal and a video signal for displaying the liquid crystal panel 441 in white are newly generated and output to the image control unit 623.
Note that when the liquid crystal panel 441 is configured as a normally black liquid crystal panel, a synchronization signal and a video signal for black display may be output to the image control unit 623.

The image control unit 623 is an image read from the memory 63 based on the image display setting information input from the drive information output unit 611 of the main control system 61 according to the operation of the operation switch 261 by the user. Based on the display setting information, the synchronization signal and the video signal input from the image conversion unit 621 are adjusted and output to the scanning driver 624 and the signal driver 625.
Further, when an interrupt signal is input from the charge equalization processing unit 622, the image control unit 623 outputs a timing signal to the start adjustment unit 626 and waits until a response signal is input from the start adjustment unit 626. . When a response signal is input from the start adjustment unit 626, a response signal for the interrupt signal is output to the charge equalization processing unit 622, and the synchronization input from the charge equalization processing unit 622 to the image control unit 623. The signal and the video signal are output to the scanning driver 624 and the signal driver 625 in place of the synchronization signal and the video signal input from the image conversion unit 621.
Further, the image control unit 623 receives the control signal for storing the image display setting information input from the drive information output unit 611 of the main control system 61 in the memory 63, and the image display setting information stored in the memory 63. A control signal to be read is output to the information reading / writing unit 628.

  The scanning driver 624 and the signal driver 625 correspond to the scanning line side driving circuit and the signal line side driving circuit of the present invention. The scanning driver 624 and the signal driver 625 are connected to the scanning line 441V and the signal line 441H of the liquid crystal panel 441, respectively, and based on the synchronization signal and the video signal output from the image control unit 623, drive signals for the liquid crystal panel 441 are transmitted. The data is output to the scanning line 441V and the signal line 441H.

The scan driver 624 includes a shift register 6241. The shift register 6241 includes a plurality of registers that hold vertical synchronization signals input from the image control unit 623. By shifting these registers in synchronization with the pulse signal generated by the clock generator 627, the drive signal of the liquid crystal panel 441 is sequentially output to the scanning line 441V.
The signal driver 625 includes a shift register 6251 and a sample / hold circuit 6252. Among these, the shift register 6251 is configured to include a plurality of registers that hold horizontal synchronization signals input from the image control unit 623, similarly to the shift register 6241. Each of these registers is shifted in synchronization with the pulse signal generated by the clock generator 627 so that the sample / hold circuit 6252 holds the video signal and sequentially outputs the held video signal to the signal line 441H.

That is, the shift register 6241 of the scan driver 624 applies a voltage of either high / low level to the scan line 441V. Specifically, the shift register 6241 applies a high level voltage to the scanning line 441V determined based on the vertical synchronization signal among the scanning lines 441V, thereby setting the scanning line 441V in a selected state. A low level voltage is applied to the other scanning line 441V to make it non-selected.
In addition, the shift register 6251 of the signal driver 625 outputs a video signal to the display pixels connected to the selected scanning line 441V via the signal line 441H, so that the video signal is held at the timing of holding the video signal. A high level voltage is applied to the sample and hold circuit 6252, and a low level voltage is applied during other periods.
The sample and hold circuit 6252 is a buffer that temporarily holds a video signal in accordance with a signal output from the shift register 6251, and supplies a video signal to the signal line 441 H of the liquid crystal panel 441.

Here, a case where the synchronization signal and the video signal generated by the charge equalization processing unit 622 are input to the scan driver 624 and the signal driver 625 via the image control unit 623 will be described.
When a synchronization signal and a video signal for displaying white on the liquid crystal panel 441 from the charge equalization processing unit 622 are input to the scanning driver 624 and the signal driver 625, the video signal output from the signal driver 625 is a voltage for displaying white. Fixed to. That is, the voltages output to the signal line 441H are all at the same level, and the charges applied to the display pixels of the liquid crystal panel 441 are almost uniformized. Thereby, when the power supply is cut off, it is possible to prevent charges from remaining in the display pixels of the liquid crystal panel 441 and causing an afterimage phenomenon.
Note that when the charge equalization process is performed, the voltage application state of the shift register 6251 may be fixed at a high level. According to this, all the display pixels connected to the scanning line 441V in the selected state of the liquid crystal panel 441 are in a writable state, and the writing time of each display pixel becomes long, so that uniform charge is surely performed. It will be.

The start adjustment unit 626 corresponds to the start adjustment unit of the present invention, and temporarily waits for processing in the image control unit 623. Specifically, when a timing signal is input from the image control unit 623, the start adjustment unit 626 receives the image control after the standby period stored in the memory 63 and read by the information reading / writing unit 628 has elapsed. A response signal is output to the unit 623. The waiting time elapsed by the start adjustment unit 626 is counted by counting the pulse signals generated by the clock generation unit 627.
The standby period of the memory 63 is the same as the period from when the power cutoff signal is input to the power regulation unit 53 until the power regulation unit 53 shuts off the power supply to the lamp drive block 52. Or more than that. Thereby, the start adjustment unit 626 can wait for the charge equalization processing by the charge equalization processing unit 622 and the image control unit 623 until the power supply to the lamp driving block 52 is cut off. It is possible to secure the power of the finite power holding unit 5113A used in the above.

(6) Processing at the time of power supply interruption FIG. 8 is a diagram showing a processing flow of processing at the time of power supply interruption.
Here, when the power supply to the projector 1 is suddenly interrupted when the connection with the external power source is disconnected or during a power failure, the power supply interruption process S (S13 to S17, S22 to S3) performed by the projector 1 is performed. S23, S32 to S33) will be described.
As shown in FIG. 8, in the power supply state, the projector 1 converts and transforms an alternating current supplied from an external power source into a direct current by the power supply block 51 of the power supply unit 5, and then controls the power regulating unit 53 and the control board. 6 is supplied to electronic components such as 6 (process S11). At this time, part of the power supplied from the external power source is held by the power holding unit 5113A.
Further, along with the start of the power supply by this processing S11, the power regulating unit 53 and the charge equalization processing unit 622 constituting the display control system 62 of the control board 6 are supplied from the cutoff signal output unit 5123 of the power supply block 51. Are monitored (steps S21 and S31).

The power supply state by this process S11 is monitored by the power supply monitoring unit 5111 constituting the power interruption detection unit (process S12), and the power supply state determination process is performed (process S13).
Here, when the power supply interruption is not detected, that is, when the power supply is normally performed, the power supply by the process S11 is continued.
On the other hand, when the power supply interruption is detected, that is, when the power supply monitoring unit 51 detects the power supply interruption, the power supply is interrupted from the power supply monitoring unit 5111 to the signal input unit 5122. A predetermined signal indicating that is output (step S14). Further, the power held in the power holding unit 5113A is automatically released due to the decrease in the applied voltage level to the power holding unit 5113A due to the power supply cutoff (processing S15). The power of the power holding unit 5113A released by this processing S15 is supplied to the booster circuit 5114 of the primary side power supply system 511, and then supplied to the power regulation unit 53 and also passes through the secondary side power supply system 512. , And supplied to a control board 6 and the like configured to include a main control system 61 and a display control system 62. Thereby, even when the power supply from the external power supply is interrupted, the processes S16 to S18 by the power supply block 51, the processes S22 to S23 by the power regulation unit 53, and the processes S32 to S33 by the display control system 62 are executed. Can do.

A signal from the power supply monitoring unit 5111 is input to the cutoff signal output unit 5123 via the signal input unit 5122, and the cutoff signal output unit 5123 determines an input duration period of this signal (processing S16). In this process S16, when it is determined that the signal input period is less than 25 msec, the cutoff signal output unit 5123 regards that the interruption of the power supply is an instantaneous power failure, returns to the process S11, and continues to monitor the power supply state again. Is done.
On the other hand, when it is determined that the signal input period is 25 msec or more, the cutoff signal output unit 5123 regards that the power supply is continuously cut off, generates a power cutoff signal, and generates the power regulation unit 53 and the display control system 62. The power cutoff signal is output to the charge equalization processing unit 622 (step S17).
By determining the signal input continuation period in the processing S16 as described above, it is considered that the power supply is cut off for a short-time power failure such as a momentary power failure that occurs when a device that supplies external commercial current or a transmission line is switched. The projector 1 can be driven stably without any problems.

Further, the monitoring of the power supply state by the power supply monitoring unit 5111 is also performed after the power cut-off signal is output by the cut-off signal output unit 5123 in the process S17. If it is determined that the power supply has been restored by determining whether the power supply has been restored (step S18), a signal indicating that the power supply has been cut off is not input to the signal input unit 5122. The output of the power cutoff signal from the signal output unit 5123 is stopped (process S19), the process returns to process S11, the power supply is restarted, and the projector 1 is normally operated. On the other hand, when the power supply is not restored, the processing in the power supply block 51 is terminated.
Note that in the case where the power supply monitoring unit 5111 is configured to include a light emitting element and the signal input unit 5122 is configured to include a light receiving element that receives light emitted from the light emitting element, light emission is performed along with restoration of power supply. Since the element emits light and this light emission can be automatically detected by the light receiving element, the determination process in step S18 can be performed easily and automatically.

In the power regulating unit 53, input monitoring of the power cutoff signal from the cutoff signal output unit 5123 is performed by the above-described process S21.
Here, in the input determination of the power shutdown signal by the power regulation unit 53 (processing S22), when the input of the power shutdown signal is not detected, the power regulation unit 53 returns to the process S21 and inputs the power shutdown signal. Continue monitoring.
On the other hand, when an input of a power cutoff signal is detected by the power regulation unit 53, the power regulation unit 53 is connected to the lamp drive block 52 from the booster circuit 5114 constituting the primary power supply system 511 of the power supply unit 5. The power supply is cut off (process S23), and the process ends while waiting until the power supply is restored.
As a result, the finite power held in the power holding unit 5113A constituting the smoothing circuit 5113 constituting the primary power supply system 511 is prevented from being consumed by the light source lamp 411A having a large amount of power consumption and reliably controlled. The electric power used for the process at the time of the electric power supply interruption | blocking in the board | substrate 6 is securable.

The charge equalization processing unit 622 of the display control system 62 performs input monitoring of the power cutoff signal from the cutoff signal output unit 5123 by the above-described process S31.
Here, when the input of the power cutoff signal from the cutoff signal output unit 5123 is not detected in the input judgment of the power cutoff signal by the charge equalization processing unit 622 (processing S32), the process returns to the processing S31 and the power cutoff signal is returned. Continue input monitoring for.
On the other hand, when the input of the power cutoff signal is detected, the charge equalization processing unit 622 starts the charge equalization processing (processing S33).

FIG. 10 is a diagram showing a processing flow of charge equalization processing.
The charge equalization processing (S331 to S339) is started when a power cut-off signal is input to the charge equalization processing unit 622. That is, when the power cut-off signal is input from the cut-off signal output unit 5123 to the charge equalization processing unit 622, the charge equalization processing unit 622 sends an interrupt signal to the image control unit 623 as shown in FIG. Output (processing S331). Thereafter, the charge equalization processing unit 622 stands by until a response signal is input from the image control unit 623.
In the power supply state, the image control unit 623 outputs a synchronization signal and a video signal to the scan driver 624 and the signal driver 625 according to the image information from the externally connected device input from the image conversion unit 621 described above. When an interrupt signal is input from the equalization processing unit 622, a time measurement signal is output to the start adjustment unit 626 (processing S332). Thereafter, the image control unit 623 stands by until a response signal is input from the start adjustment unit 626.

The start adjusting unit 626 to which the time signal is input measures the time corresponding to the standby period read from the memory 63 by the information reading / writing unit 628 (processing S333). Specifically, the start adjustment unit 626 counts a pulse signal generated by the clock generation unit 627 of the display control system 62 and corresponding to the standby period, and elapses the time corresponding to the standby period.
In the standby period recorded in the memory 63, as described above, after the power cut-off signal is output to the power regulating unit 53 by the process S16, the power regulating unit 53 sends the lamp driving block 52 to the lamp driving block 52 in the process S23. The period is the same as or longer than the period until the power supply is cut off. Thus, after the power supply to the lamp driving block 52 is cut off, white display on a liquid crystal panel 441 described later in the charge equalization process is performed to secure power used in the charge equalization process. The charge equalization process can be executed reliably. In addition, since no power is supplied to the light source device 411 and illumination of the liquid crystal panel 441 by the light source device 411 is stopped, a white display image formed by the liquid crystal panel 441 is not projected, which is uncomfortable for the user. Can be prevented.

In process S333, the start adjustment unit 626 which has timed the standby period outputs a response signal indicating that the standby period has elapsed to the image control unit 623 in the standby state (process S334).
The image control unit 623 released from the standby state upon receiving this response signal outputs a response signal indicating that the time for the standby period has elapsed to the charge equalization processing unit 622 in the standby state (processing) S335).

  The charge equalization processing unit 622, which receives a response signal from the image control unit 623 and is released from the standby state, displays a synchronization signal for causing the liquid crystal panel 441 to display white in order to make the charge of each display pixel of the liquid crystal panel 441 uniform. A video signal is generated (processing S336). In this process S336, the charge equalization processing unit 622 generates a video signal having a voltage corresponding to the white level voltage that the signal driver 625 applies to the signal line 441H of the liquid crystal panel 441. Thereafter, the charge equalization processing unit 622 outputs the generated synchronization signal and video signal to the image control unit 623 (processing S337), and the image control unit 623 outputs the synchronization signal and video signal to the scanning driver 624 and the signal driver. It outputs to 625 (process S338).

  The scan driver 624 and the signal driver 625 output drive signals to the scan line 441V and the signal line 441H of the liquid crystal panel 441 based on the synchronization signal and the video signal input from the image control unit 623 in step S338, and the liquid crystal panel 441 is displayed in white (processing S339).

In this process S339, a synchronization signal and a video signal for displaying white on the liquid crystal panel 441 configured as a normally white type are input to the scanning driver 624 and the signal driver 625. As a result, the uniform charge is applied to each display pixel of the liquid crystal panel 441, thereby preventing the charge based on the image information output from the image conversion unit 621 from remaining on the liquid crystal panel 441. The afterimage phenomenon of an image can be suppressed.
As a result of the completion of the process S339, the charge equalization process is completed, and accordingly, the power supply cutoff process is completed.

The projector 1 configured as described above can provide the following effects.
That is, when the power supply from the external power source to the projector 1 is cut off, the power cut-off detection unit configured by the power supply monitoring unit 5111, the signal input unit 5122, and the cut-off signal output unit 5123 of the power supply block 51 Supply interruption is detected and a power interruption signal is output. Based on the power cutoff signal, the display control system applies a uniform charge to the liquid crystal panel 441 by the holding power of the power holding unit 5113A, whereby the charge based on the image information output from the external device to the liquid crystal panel 441. Can be prevented, and the afterimage phenomenon can be suppressed.

  The power shutdown detection unit includes a power supply monitoring unit 5111 of the primary power supply system 511, a signal input unit 5122 and a shutdown signal output unit 5123 of the secondary power supply system 512, and the power shutdown signal The signal is input from the signal output unit 5123 to the display control system 62. According to this, since the power supply monitoring unit 5111 is provided in the primary side power supply system 511, it is possible to quickly detect the interruption of the power supply. In addition, a signal input unit 5122 and a cutoff signal output unit 5123 that receive a signal from the power supply monitoring unit 5111 and generate and output a power cutoff signal based on this signal are provided in the secondary power supply system 512. Thus, when the power supply is cut off, a power cut-off signal can be output using the power held in the power holding unit 5113A. Therefore, it is possible to reliably output a power cutoff signal to the display control system 62 and the like.

Further, the power cutoff signal is input to the display control system 62 that controls the liquid crystal panel 441, and the display control unit 62 performs the charge equalization process. Compared with the case where the power shutoff signal is input to the control system 61 and the charge equalization process is performed under the control of the main control system 61, the charge equalization process can be executed more quickly. Therefore, the charge equalization process can be quickly performed before the entire power held in the power holding unit 5113A is consumed.
In addition, the power cutoff signal is output to the power regulation unit 53, and the power regulation unit 53 cuts off the power supply to the lamp driving block 52. Therefore, the power held in the power holding unit 5113A is changed to the light source lamp 411A. It is possible to prevent consumption by lighting up. Therefore, the finite power held in the power holding unit 5113A can be effectively used. In addition, since the liquid crystal panel 441 during the above-described charge equalization process is not illuminated by the light source lamp 411A, it is possible to prevent the white display screen from being projected, and to prevent the user from feeling uncomfortable. can do.

(7) Modification of Embodiment The best configuration for carrying out the present invention has been disclosed above, but the present invention is not limited to this. That is, the invention has been illustrated and described primarily with respect to particular embodiments, but may be configured for the above-described embodiments without departing from the scope and spirit of the invention. Various modifications can be made by those skilled in the art in terms of materials, quantity, and other detailed configurations.
Therefore, the description limiting the shape, material, etc. disclosed above is an example for easy understanding of the present invention, and does not limit the present invention. The description by the name of the member which remove | excluded the limitation of one part or all of such is included in this invention.

In the above embodiment, the projector 1 is taken as an example of the image display device. However, the present invention is not limited to this, and the present invention is applied to a liquid crystal display and a display-integrated personal computer such as a notebook computer. Also good.
Further, although an example of the front type projector 1 that projects an optical image from the direction of observing the screen has been given, the present invention also applies to a rear type projector that projects an optical image from the side opposite to the direction of observing the screen. Applicable.
Further, in the present embodiment, a TFT liquid crystal panel is employed as the display unit body, but a TFD liquid crystal panel may be employed.

  In the embodiment, the normally white liquid crystal panel 441 is employed as the display unit body. However, the present invention is not limited to this, and a normally black liquid crystal panel may be employed. In this case, by applying a voltage for displaying the liquid crystal panel in black, that is, by applying a minimum voltage to each display pixel of the liquid crystal panel, it is possible to achieve the same effect as when a normally white liquid crystal panel is employed. . That is, the voltage applied to each display pixel can be a minimum uniform voltage that causes the liquid crystal panel to display black, and the charge accumulated in the liquid crystal panel is thereby uniformized. The afterimage phenomenon can be suppressed.

Similarly, the signal generated by the charge equalization processing unit 622 is not limited to a signal that causes the liquid crystal panel 441 to display white, and may be another color as long as it is a single color. That is, any signal that applies a uniform charge to each display pixel of the liquid crystal panel 441 may be used.
Note that if the liquid crystal panel 441 is a normally white type or a normally black type and each is a signal for displaying white or black, the applied voltage can be set to a minimum low voltage. Can be prevented from remaining.

  In the embodiment, when the charge equalization process is performed, voltage application to the shift register 6251 of the signal driver 625 is performed so that all display pixels connected to the scanning line 441V in the selected state of the liquid crystal panel 441 can be written. Although the state is set to the high level, the voltage application state of the shift register 6241 of the scan driver 624 may be set to the high level. For example, when all the scanning lines 441V are selected by the uniform drive signal from the shift register 6241, the video signal applied to the signal line 441H is applied to the display pixels connected to the scanning lines 441V. Thus, it is possible to prevent the charge based on the image information from remaining in each display pixel of the liquid crystal panel 441.

  In the above embodiment, the capacitor constituting the smoothing circuit 5113 is the power holding unit 5113A. However, the present invention is not limited to this, and an auxiliary power source such as a battery may be provided as the power holding unit. If the capacitor constituting the smoothing circuit 5113 is used as the power holding unit 5113A, the power holding unit can be constructed by increasing the holding capacity of the capacitor constituting the smoothing circuit of the general-purpose power supply unit. Not only can the unit be used, but also the number of members can be reduced and the configuration can be simplified.

In the above-described embodiment, the configuration in which the optical unit 4 has a substantially L shape in plan view has been described. However, the configuration is not limited thereto, and for example, a configuration having a substantially U shape in plan view may be employed.
In the above-described embodiment, the transmissive liquid crystal panel 441 having a different light beam incident surface and light beam emission surface is used. However, a reflective liquid crystal panel having the same light incident surface and light emission surface may be used.

  The present invention can be used not only for a projector but also for an image display device that has a liquid crystal panel in which a liquid crystal material is hermetically sealed and obtains electric power from an external power source and is driven.

The perspective view which looked at the projector which concerns on one Embodiment of this invention from the upper front side. The perspective view which looked at the projector in the said embodiment from the downward front side. The perspective view which looked at the projector in the said embodiment from the upper back side. The perspective view which shows the internal structure of the projector in the said embodiment. The schematic diagram which shows the optical unit in the said embodiment. The block diagram which shows the whole structure of the power supply unit and control board in the said embodiment. The block diagram which shows the detailed structure of the power supply unit in the said embodiment. The block diagram which shows the detailed structure of the control board in the said embodiment. The figure which shows the processing flow of the process at the time of the electric power supply interruption | blocking in the said embodiment. The figure which shows the processing flow of the charge equalization process in the said embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Projector (image display apparatus), 5 ... Electric power unit (electric power supply means), 53 ... Electric power control part (electric power control means), 62 ... Display control system, 441 (441R, 441G, 441B) ... Liquid crystal panel (display part) Main body), 511... Primary power supply system, 512. Secondary power supply system, 622. Charge equalization processing unit (charge equalization processing means), 623... Image control unit, 624. Circuit), 625... Signal driver (signal line side drive circuit), 626... Start adjustment unit (start adjustment means), 411A... Light source lamp (light source), 441H. (Power cutoff detection unit), 6241... Shift register, 6251... Shift register, 5113A.

Claims (7)

A plurality of signal lines arranged substantially parallel to each other on the substrate, a plurality of scanning lines arranged in a direction substantially orthogonal to the arrangement direction of the plurality of signal lines so as to intersect with each of the plurality of signal lines, and A display unit body including a plurality of display pixels connected to the respective signal lines and scanning lines, and the plurality of signal lines and the plurality of scanning lines, respectively, in accordance with input image information. An image display device comprising: a display control system that drives and controls the display pixels; and a power supply unit that supplies power to the display unit main body and the display control system,
The power supply means
A power cut-off detection unit that monitors a power supply state from an external power source and outputs a power cut-off signal to the display control system when the power supply is cut off;
A part of the power supplied from the external power source is held, and the power holding unit that supplies the power held when the power supply is cut off to the display control system and the display unit main body is provided,
The display control system is
Charge equalization processing means is provided for equalizing charges accumulated in the display pixels of the display unit main body based on the power supplied from the power holding unit when the power cutoff signal is input. An image display device characterized by the above. The image display device according to claim 1,
The power supply means
A primary power supply system for converting alternating current input from the external power source into direct current;
A secondary power supply system that converts the voltage of the power converted into a direct current into a predetermined voltage;
The image display apparatus, wherein the power holding unit is a circuit element constituting the primary power supply system. The image display device according to claim 1 or 2,
The power supply means is electrically connected to a light source that illuminates the display unit body,
The image display apparatus according to claim 1, wherein the power supply unit includes a power regulation unit that regulates power supply to the light source when it is detected that the power supply is cut off by the power cut-off detection unit. The image display device according to claim 3.
The image display apparatus according to claim 1, wherein the display control system includes a start adjustment unit for timing the power supply regulation by the light source power regulation unit and the homogenization process by the charge uniformization unit. The image display device according to any one of claims 1 to 4,
An image control unit that performs image output control based on input image information,
The image display apparatus according to claim 1, wherein the charge equalization processing means outputs a signal for displaying a monochromatic image on the display unit main body to the image control unit to perform a uniformization process. The image display device according to any one of claims 1 to 4,
The display control system is
A scanning line side drive circuit including a shift register provided on the input side of each of the scanning lines and configured to apply a voltage of two levels to each of the scanning lines;
A signal line side drive circuit provided on the input side of each of the signal lines, each of the signal lines having a two-level voltage application state and another shift register;
The charge equalization processing means performs charge equalization processing by aligning the voltage application state of one of the shift registers of the scanning line side driving circuit and the signal line side driving circuit. Display device. The image display device according to any one of claims 1 to 6,
The display unit body is configured as a normally white type or a normally black type,
The charge equalization processing means applies a voltage for displaying white when the display unit body is a normally white type, and applies a voltage for displaying black when the display unit body is a normally black type. An image display device characterized by the above.

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