Abstract: A projector (image display apparatus) having enhanced visual mute or A/V mute functions includes a light modulation element for displaying an image, a lamp for illuminating the light modulation element, and a fan for cooling the lamp; the image display apparatus further includes a visual mute means for setting a visual mute mode in which no image or a predetermined image is displayed on a display screen thereof, and a lamp output luminance adjusting means for adjusting the output luminance of the lamp in response to the setting and canceling of the visual mute mode by the visual mute means.

Abstract: A projector (image display apparatus) having enhanced visual mute or A/V mute functions includes a light modulation element for displaying an image, a lamp for illuminating the light modulation element, and a fan for cooling the lamp; the image display apparatus further includes a visual mute means for setting a visual mute mode in which no image or a predetermined image is displayed on a display screen thereof, and a lamp output luminance adjusting means for adjusting the output luminance of the lamp in response to the setting and canceling of the visual mute mode by the visual mute means.

Abstract: The present invention provides an image processing circuit having a D/A converter that converts input image data Da to an analog signal to generate an image signal VID. The output range of the D/A converter is controlled by an output-range control signal CTLout having a different signal level according to the type of a liquid-crystal display panel used. Therefore, a range where the signal level of the image signal VID is changed can be adjusted according to the type of the liquid-crystal display panel. Consequently, even when an image-signal processing circuit is used with one of a plurality of types of liquid-crystal display panels having different V-T characteristics, since the data values of input image data Da can be assigned to a desired applied-voltage range, high-definition images can be displayed.

Abstract: A liquid crystal device having multiple pixels includes an input terminal that receives a display signal including multiple pixel signals to be supplied to the multiple pixels. The display signal has a predetermined signal embedded therein for generating a common signal, which is to be commonly supplied to the multiple pixels, during a predetermined period that does not include the pixel signals in the display signal. The liquid crystal device further includes: a common signal line that is commonly connected to the multiple pixels; and a common signal line driving circuit that generates the common signal in response to the predetermined signal included in the display signal input from the input terminal and supplies the generated common signal to the common signal line. Such arrangement desirably enhances the reliability of the liquid crystal device.

Abstract: When a video signal is inputted to a projector (10) through a video input terminal, a luminance peak value of an image of the video signal is detected by an image-analyzing circuit (61) to be outputted to a CPU (71). A gain-adjusting circuit (63) adjusts a luminance signal in the video signal based on a command from the CPU (71). The CPU (71) determines a gain adjustment amount based on the luminance peak value of the image obtained by the image-analyzing circuit (61) and outputs the result to the gain-adjusting circuit (63). For instance, when the luminance peak value (Ip) of the image is 50% of the upper limit (Imax) thereof, a gain-adjusting amount AG is doubled. In this case, an illuminating light volume of a light valve (44a) has to be reduced to 50%, which is achieved by light-attenuation by a light-source lamp (21) and an open/close light shield (23).

Abstract: When a video signal is inputted to a projector (10) through a video input terminal, a luminance peak value of an image of the video signal is detected by an image-analyzing circuit (61) to be outputted to a CPU (71). A gain-adjusting circuit (63) adjusts a luminance signal in the video signal based on a command from the CPU (71). The CPU (71) determines a gain adjustment amount based on the luminance peak value of the image obtained by the image-analyzing circuit (61) and outputs the result to the gain-adjusting circuit (63). For instance, when the luminance peak value (lp) of the image is 50% of the upper limit (Imax) thereof, a gain-adjusting amount AG is doubled In this case, an illuminating light volume of a light valve (44a) has to be reduced to 50%, which is achieved by light-attenuation by a light-source lamp (21) and an open/close light shield (23).

Abstract: A projector has an illuminating optical system for irradiating white light, a color switching optical system for dividing the white light irradiated by the illuminating optical system into color lights in a time-division manner, a DMD™ for modulating the respective color lights in accordance with an image signal, a projection optical system for projecting the light beam modulated by the DMD, a light-composite optical system for getting the light beam not incident on the projection optical system to be incident again on the DMD and a device controller for controlling the operation of the projector, where the light beam irradiated by the DMD and not incident on the projection optical system is irradiated as a light beam of uniform illuminance distribution by the light-composite optical system and is again introduced on an illumination optical axis to be incident on the DMD, thus enhancing peak luminance of the projected image and achieving high contrast ratio.

Abstract: An image display apparatus including an image correction section, a data storage device, and an image forming section. The image correction section corrects levels of given image data in accordance with the correction data stored in the data storage device. The image forming section is provided with a plurality of pixels each transmitting image-forming light responsive to corrected image data supplied from the image correction section, and the image-forming light reproduces a displayed image. The correction data are determined by obtaining data-correction values based on input-output characteristics of the image forming section. The data-correction values represent correction amounts of the image data needed to bring, closer to a predetermined reference level, the output levels of light at a plural locations of a displayed image which is displayed responsive to uniform image data representing a specific uniform image.

Abstract: A projector capable of setting and storing usage environment data peculiar to each user in a selectable manner is provided, thereby facilitating reduction of trouble and time of resetting when reusing. The liquid crystal projector samples and reproduces image signals input from a computer in accordance with display pixels. This liquid crystal projector selectably stores usage environment data peculiar to each user, selects the stored usage environment data the next time the liquid crystal projector is used, and reproduces image signal input based on the selected usage environment data.

Abstract: A projector in which the effect of functions of visual mute or A/V mute are enhanced is provided. A image display apparatus includes a light modulation element for displaying an image, a lamp for illuminating light modulation element, and a fan for cooling a lamp, and the image display apparatus further includes a visual mute means for setting a visual mute mode in which no image or a predetermined image is displayed on a display screen thereof, and a lamp output luminance adjusting means for adjusting the output luminance of the lamp in response to the setting and canceling of the visual mute mode by the visual mute means.

Abstract: A projector has an illuminating optical system for irradiating white light, a color switching optical system for dividing the white light irradiated by the illuminating optical system into color lights in a time-division manner, a DMD™ for modulating the respective color lights in accordance with an image signal, a projection optical system for projecting the light beam modulated by the DMD, a light-composite optical system for getting the light beam not incident on the projection optical system to be incident again on the DMD and a device controller for controlling the operation of the projector, where the light beam irradiated by the DMD and not incident on the projection optical system is irradiated as a light beam of uniform illuminance distribution by the light-composite optical system and is again introduced on an illumination optical axis to be incident on the DMD, thus enhancing peak luminance of the projected image and achieving high contrast ratio.

Abstract: A display device in which brightness and contrast in an electro-optical device are improved, and gain adjustment and brightness adjustment are not necessary. The present invention provides a device which drives a liquid crystal device in which light transmittance ratio changes based on applied voltage. Furthermore, a digital picture signal is gamma-corrected in a digital gamma correction circuit, and subsequently converted into an analog signal in a D/A conversion block and supplied to the liquid crystal device. The digital gamma correction circuit converts an 8-bit digital picture signal into a 10-bit digital picture signal based on gamma correction characteristics predetermined by applied voltage-transmittance characteristics inherent in the liquid crystal device in the entire transmittance range of 0% and 100%.

Abstract: A display device in which brightness and contrast in an electro-optical device are improved, and gain adjustment and brightness adjustment are not necessary. The present invention provides a device which drives a liquid crystal device in which light transmittance ratio changes based on applied voltage. Furthermore, a digital picture signal is gamma-corrected in a digital gamma correction circuit, and subsequently converted into an analog signal in a D/A conversion block and supplied to the liquid crystal device. The digital gamma correction circuit converts an 8-bit digital picture signal into a 10-bit digital picture signal based on gamma correction characteristics predetermined by applied voltage-transmittance characteristics inherent in the liquid crystal device in the entire transmittance range of 0% and 100%.

Abstract: A liquid crystal device having multiple pixels includes an input terminal that receives a display signal including multiple pixel signals to be supplied to the multiple pixels. The display signal has a predetermined signal embedded therein for generating a common signal, which is to be commonly supplied to the multiple pixels, during a predetermined period that does not include the pixel signals in the display signal. The liquid crystal device further includes: a common signal line that is commonly connected to the multiple pixels; and a common signal line driving circuit that generates the common signal in response to the predetermined signal included in the display signal input from the input terminal and supplies the generated common signal to the common signal line. Such arrangement desirably enhances the reliability of the liquid crystal device.

Abstract: The present invention provides an image processing circuit having a D/A converter that converts input image data Da to an analog signal to generate an image signal VID. The output range of the D/A converter is controlled by an output-range control signal CTLout having a different signal level according to the type of a liquid-crystal display panel used. Therefore, a range where the signal level of the image signal VID is changed can be adjusted according to the type of the liquid-crystal display panel. Consequently, even when an image-signal processing circuit is used with one of a plurality of types of liquid-crystal display panels having different V-T characteristics, since the data values of input image data Da can be assigned to a desired applied-voltage range, high-definition images can be displayed.

Abstract: An image display apparatus comprises an image correction section, a data storage device, and an image forming section. The image correction section corrects levels of given image data in accordance with the correction data stored in the data storage device. The image forming section is provided with a plurality of pixels each emitting image-forming light responsive to corrected image data supplied from the image correction section, and the image-forming light reproduces a displayed image. The correction data are determined by obtaining data-correction values on the basis of input-output characteristics of the image forming section. The data-correction values represent correction amounts of the image data needed to bring, closer to a predetermined reference level, the output levels of light at a plural locations of a displayed image which is displayed responsive to uniform image data representing a specific uniform image.

Abstract: A display device performs various types of adjustment by canceling luminance dispersion caused by a light source at the time of optical illumination from the light source and correctly sets a gamma correction characteristic even when optical power from the light source varies or is abnormal. In luminance measurement of a display device, an adjustment method includes measuring transmitted light using a sensor and a reference sensor, calculating correction values on the basis of fluctuation values of reference data derived from measured data by the sensor and the reference data by the reference sensor, correcting the measured data, and thereafter converting the data into gradation values.

Abstract: Methods and apparatus for using more effectively the front side area of a rear projection display as a screen positioning area disclosed. Almost all of the p-polarized light beams emitted from an image projector are reflected by a polarizing selection element, and almost all of the reflected light beams are converted into s-polarized light beams by a polarizing conversion mirror as the light beams are reflected towards a screen. Of the s-polarized light beams produced as the light beams are reflected by the polarizing conversion mirror, those that are not incident upon the polarizing selection element strike the screen in order to form an image. On the other hand, those that are incident upon the polarizing selection element pass through the polarizing selection element and strike the screen in order to form an image thereon.

Abstract: To provide an image display apparatus in which, even if pixel data is phase-expanded, the influence of differences in circuit characteristic can be dispersed between frames. The apparatus has a phase expansion circuit 380 to which are input a first video signal A1 having pixel data for driving pixels with positive voltages and a second video signal A2 having pixel data for driving pixels with negative voltages. The phase expansion circuit 380 forms six phase-expanded signals V1 to V6 from the first and second video signals A1 and A2. The phase-expanded signals are expanded into pixel data by extending the data length of items of the pixel data corresponding to some of the pixels periodically selected. The phase expansion circuit 380 outputs the phase-expanded signals to phase-expanded signal output lines in parallel with each other.

Abstract: A projection-type video display in which the entire input video signal is first digitally corrected through digital gamma correction. Then, a subset of the corrected video signal is corrected again through analogue correction techniques. In particular this portion of the digitally corrected video signal corresponds to the subject where slopes of applied voltage-transmissivity characteristic curve (V-T curve) of liquid crystal changes relatively rapidly. The result is a more accurate gamma correction which is also less expensive than conventional, purely digital gamma correction systems.