Abstract: A calculating unit of a master apparatus that comes first in a transmission sequence calculates coordinates of a plurality of video display apparatuses on a multiscreen on the basis of arrangement information and the transmission sequence. The calculating unit an identification number on the basis of an identification setting rule. A setting unit performs a processing for setting the identification number of each of the video display apparatuses with the calculated coordinates to the video display apparatus concerned.

Abstract: In a multi-screen display apparatus according to the present invention, a master image display apparatus acquires determination results obtained by an input detector and acquires a video signal of which channel is selected by a selector from each of a plurality of image display apparatuses including the master image display apparatus. In a case where the selector of any of the image display apparatuses selects a video signal of a channel that is not input to the video receiver, the master image display apparatus controls the selector of the image display apparatus to select a video signal of another channel that is input to the video receiver and controls the selector of at least one of the others of the image display apparatuses to select a video signal of the other channel.

Abstract: A light source control device includes a constant-current circuit that collectively supplies a current to a plurality of LEDs, a current detection circuit that divides the plurality of LEDs into groups and detects a current amount of a current supplied to each of the groups, and a microcomputer that detects an open fault in the LEDs on the basis of a ratio of the current amount in each of the groups and controls a current supplied from the constant-current circuit to be reduced in a case where an open fault is detected in the LEDs.

Abstract: A projection type video display includes a light source including light source parts, which are the LED arrays each including six LEDs, for every predetermined colors; a light source controller time-division driving each of the light source parts at a timing based on an input video signal to be input from the outside; and a video display device modulating light emitted from each of the light source parts based on the input video signal and projecting the modulated light onto a screen, wherein the light source controller controls only three LEDs among the six LEDs to turn on in each driving of the time-division driving of each of the light source parts.

Abstract: A video display device drives LEDs to emit light by light source driving circuits, detects maximum signal levels for the respective colors from video signals for an amount of n screens (n is an integer equal to or larger than one), and calculates amplification factors for the respective colors based on the detected maximum signal levels. In addition, the video display device amplifies the signal levels of the video signals based on the amplification factors for the respective colors calculated in a power saving mode for reducing power consumption, and controls drive current values of the LEDs to be respectively supplied to the light source driving circuits so as to cancel amplification amounts of brightnesses of the LEDs that correspond to amplification amounts of the signal levels of the video signals amplified.

Abstract: A microcomputer of a light source control device specifies an LED belonging to LEDs and subjected to a short-circuit failure based on a result of determination by a short-circuit failure detecting circuit and current amounts sensed by current sensing circuits respectively. The microcomputer makes corresponding one of switching elements interrupt supply of a current to the specified LED. The microcomputer makes a constant current circuit supply an LED not specified with a current not exceeding a current responsive to the number of such LEDs not specified.

Abstract: A microcomputer calculates a target brightness per brightness mode. Each projection video image display device specifies a target control current value corresponding to a calculated target brightness corresponding to a brightness mode set to the projection video image display device. Each projection video image display device supplies a current indicating the specified control current value to a light source of the projection video image display device.

Abstract: A microcomputer of a light source control device specifies an LED belonging to LEDs and subjected to a short-circuit failure based on a result of determination by a short-circuit failure detecting circuit and current amounts sensed by current sensing circuits respectively. The microcomputer makes corresponding one of switching elements interrupt supply of a current to the specified LED. The microcomputer makes a constant current circuit supply an LED not specified with a current not exceeding a current responsive to the number of such LEDs not specified.

Abstract: An image data processing apparatus of the present invention includes: a base clock output circuit for outputting a base clock; a plurality of image processors; and a plurality of external PLL circuits provided for each one of the plurality of image processors. The plurality of external PLL circuits each synchronize an output clock given from a corresponding one of the plurality of image processors with the base clock.

Abstract: There has been a problem of displacement of luminance and chromaticity among multiple screens due to a temperature change and a temporal change of a light source of the screen.

Abstract: A multi-screen display apparatus is a multi-screen display apparatus in which screens of a master apparatus and slave apparatuses are arranged. Each of the master apparatus and the slave apparatuses includes a light source for three primary colors formed of a semiconductor light emitting element, and a memory circuit for storing a brightness corresponding to a control current that is specific to each of the primary colors of the light source. The master apparatus determines a common target brightness based on the brightness outputtable by the master apparatus itself and the brightnesses outputtable by other apparatuses. Each of the master apparatus and the slave apparatuses reads, as a target control current, the control current corresponding to the target brightness from the memory circuit, and supplies the target control current to the light source.

Abstract: A multi-display system includes: a video window arrangement and display unit that arranges and displays all the video windows, which should be displayed, only on some displays in a multi-display constructed by arraying a plurality of displays; and a power supply controller that controls power of the display in which the video window is not displayed.

Abstract: A video display device drives LEDs to emit light by light source driving circuits, detects maximum signal levels for the respective colors from video signals for an amount of n screens (n is an integer equal to or larger than one), and calculates amplification factors for the respective colors based on the detected maximum signal levels. In addition, the video display device amplifies the signal levels of the video signals based on the amplification factors for the respective colors calculated in a power saving mode for reducing power consumption, and controls drive current values of the LEDs to be respectively supplied to the light source driving circuits so as to cancel amplification amounts of brightnesses of the LEDs that correspond to amplification amounts of the signal levels of the video signals amplified.

Abstract: A projection type video display includes: a light source including light source parts, which are the LED arrays each including six LEDs, for every predetermined colors; a light source controller time-division driving each of the light source parts at a timing based on an input video signal to be input from the outside; and a video display device modulating light emitted from each of the light source parts based on the input video signal and projecting the modulated light onto a screen, wherein the light source controller controls only three LEDs among the six LEDs to turn on in each driving of the time-division driving of each of the light source parts.

Abstract: An object of the present invention is to provide a position detecting device that allows simultaneous use by a plurality of users by recognizing positional information about a plurality of pointers and associating the pointers and the users. A position detecting device of the invention includes a rear projector that projects an image, a projection screen that displays the image projected from the rear projector, imaging means that is located near the rear projector and that takes an image of light rays emitted from pointers, from the rear of the projection screen, and coordinate calculating means that analyzes the image taken by the imaging means to detect the two-dimensional positions in the detection areas where the light rays from the pointers are detected.

Abstract: In the case where luminance of light to be irradiated onto a multi-screen is not homogenized over the entire multi-screen, each of an image display apparatus and image display apparatuses carries out a homogenizing process of light to be irradiated onto a multi-screen over the entire multi-screen.

Abstract: A multi-screen display apparatus is a multi-screen display apparatus in which screens of a master apparatus and slave apparatuses are arranged. Each of the master apparatus and the slave apparatuses includes a light source for three primary colors formed of a semiconductor light emitting element, and a memory circuit for storing a brightness corresponding to a control current that is specific to each of the primary colors of the light source. The master apparatus determines a common target brightness based on the brightness outputtable by the master apparatus itself and the brightnesses outputtable by other apparatuses. Each of the master apparatus and the slave apparatuses reads, as a target control current, the control current corresponding to the target brightness from the memory circuit, and supplies the target control current to the light source.

Abstract: A position detecting device and method implemented therein that is able to accurately detect an indicated position even when a water droplet or the like is formed upon the position-detecting-device's surface. The device includes: a light-guide plate placed upon a displaying surface of a displaying device; an emitting unit for emitting light beams that are totally reflected thickness-wise within the light-guide plate, so as to scan along the sides of the light-guide plate in an X-axis and a Y-axis direction under the control of an emission-control unit; an indicating device; and a coordinate calculating unit. In the indicating device, a light-guiding part guides light traveling within the light-guide plate into a detection unit, which detects the guided light in order to output a detection signal. The coordinate calculating unit calculates a coordinate position by deriving a scanned position from the detection signal and the emission-control unit.

Abstract: There has been a problem of displacement of luminance and chromaticity among multiple screens due to a temperature change and a temporal change of a light source of the screen.

Abstract: In a high-efficiency encoder which performs motion-compensation prediction, an intra-field is set every n fields. The presence of a scene change is detected. When a scene change occurs, a reference picture of motion-compensation prediction is switched, or the field immediately after the scene change is set as an intra-field.