Abstract: A voltage supplied from a power supply is boosted by a boosting circuit unit to generate a direct-current voltage, and the pulse-shape direct-current voltage is applied to LED while a constant-voltage control unit controls the direct-current voltage. The operation of LED is controlled by a control unit and a PWM unit. When the current is passed through LED, the constant-voltage control unit obtains information on the current passed through LED from a potential difference between both ends of a resistor, and on-and-off control of the voltage applied to LED from the boosting circuit unit is performed at a high frequency based on the information. Therefore, the voltage applied to LED can be controlled to keep the current passed through LED constant.

Abstract: The display unit of the present invention includes a metal reinforcing component that reinforces a handle portion that is formed integrally with a rear surface side of a synthetic resin housing and has a finger insertion space provided on a bottom side thereof. As a result, strength can be secured without the thickness of the handle plate portion being made thicker.

Abstract: A projector has an acceleration sensor for detecting a tilt angle of the projector, a manual controller for manually setting a correction amount for a keystone distortion correction, an auto/manual switch, an upper edge basis corrector for determining parameters for an upper edge basis keystone distortion correction, a lower edge basis corrector for determining parameters for a lower edge basis keystone distortion correction, and an image processor for performing a keystone distortion correction on the image on the basis of the upper edge or lower edge in accordance with parameters applied thereto from the upper edge basis corrector or lower edge basis corrector to display the corrected image on a liquid crystal panel or the like. As the auto/manual switch selects an automatic adjustment, the acceleration sensor and upper edge basis corrector are connected to the image processor. As a manual adjustment is selected, the manual controller and lower edge basis corrector are connected to the image processor.

Abstract: A noise suppressor for an apparatus having a cooling fan and cooling duct includes a muffler including a reflection plate for reflecting sound from the cooling fan, the reflection plate being provided at a position in the cooling duct confronting the intake plane of the cooling fan and formed substantially parallel to the intake plane. A sound-absorbing part of the muffler is provided on the reflection plate, and a distance d between the reflection plate and the intake plane is set such that d<c/(2×f) where f is the sound-absorption frequency of the muffler and c is the speed of sound.

Abstract: A distance measuring system comprising: a transmitter that simultaneously emits an infrared radiation and an ultrasonic wave; and a receiver that include a table showing a relationship between an arrival time, indicative of a period from detection of the received infrared radiation to detection of the received ultrasonic wave, and a required received signal strength of the ultrasonic wave corresponding to the arrival time when the ultrasonic wave is directly received, that compares the received signal strength of the ultrasonic wave with a required received signal strength corresponding to the arrival time retrieved from the table, and that calculates the distance to the transmitter based on the arrival time when the received signal strength of the ultrasonic wave is higher than the required received signal strength corresponding to the arrival time retrieved from the table.

Abstract: An image display apparatus has an A/D converter for sampling an analog video signal whose signal level changes at a frequency higher than the frequency of a synchronizing signal, based on a reproduced dot clock, and converting the sampled analog video signal into a digital video signal, a clock adjusting circuit for generating a clock in synchronism with the synchronizing signal, delaying the phase of the clock according to set delays, and outputting the delayed clock as the reproduced dot clock, a controller for dividing an area of an image displayed based on the converted digital video signal, into a plurality of image areas defined by display lines in a horizontal direction, and establishing different delays for the divided image areas, and a delay evaluating circuit for converting differential data between adjacent signal levels on the display lines for the respective image areas, into absolute values and accumulatively adding the absolute values, thereby producing accumulated sums.

Abstract: An object of the present invention is to provide illumination optics that enables improvement in brightness and reestablishment of an irradiation state which is provided with illumination light and which corresponds with a display area, and is to provide illumination optics including a first fly-eye lens and a second fly-eye lens where emission light from the first fly-eye lens enter, wherein at least one of lens elements configuring the second fly-eye lens covers an irradiation area smaller than an irradiation area provided by the second fly-eye lens.

Abstract: In a projection display device that is provided with a relay lens for converting flux that is emitted from a light source to a parallel flux for illuminating an image display element (DMD), and a total internal reflection prism for both directing flux that is emitted from the relay lens to the DMD and directing flux that is reflected by the DMD toward a projection lens, the relay lens is unified with the prism as a lens-integral prism by bonding the relay lens to the total internal reflection surface of the prism.

Abstract: An image displaying device with an image cache data storage unit, including: an image cache identifier generating unit that obtains a hash value of a fixed length from sampling data of original image data and generates an image cache identifier unique to said original image data based on the hash value of a fixed length; an image cache searching unit that checks whether image cache data to which the generated image cache identifier is added is stored in said image cache memory or not; and an image cache generating unit that, when the image cache data has been not stored in said image cache memory, generates image cache data by adding the image cache identifier generated by said image cache identifier generating unit to the original image data and stores the image cache data in said image cache memory.

Abstract: A liquid crystal display device includes a liquid crystal panel including a plurality of liquid crystal cells, a common voltage generation circuit that supplies a common voltage to the liquid crystal panel, a liquid crystal drive circuit that implements control for supplying said plurality of liquid crystal cells with voltage that accords with a video signal to display an image on the liquid crystal panel, and for reversing a polarity of the voltage supplied to the plurality of liquid crystal cells, and an adjustment module that stores characteristics data for correcting fluctuations in brightness and, based on said characteristics data, adjusts the brightness of the image displayed on the liquid crystal panel.

Abstract: The present invention is addresses to the conventional problem that when the distortion of a projected image that is obliquely projected onto a screen is corrected, an imaging device that is installed near a projection lens for performing an electronic blackboard function directly captures the distortion-corrected image but fails to perform the electronic blackboard function. According to the present invention, an image which is distorted from a rectangular shape into a horizontal and trapezoidal shape in a direction opposite to the direction of the distortion on the screen is displayed on a light bulb and projected through the projection lens. The distortion of the image displayed on the screen is corrected, and the image is visually perceived as a corrected projected image having a rectangular profile. At this time, the imaging device which has captured the corrected projected image outputs a captured image.

Abstract: A projector having a focusing lens comprises a position detector for detecting the position of the focusing lens, an image forming element for modulating light based on a video signal to form an image, a data recording unit having stored therein a correlation table indicative of a relationship between the position of the focusing lens and the amplitude of the video signal applied to the image forming element, a processing unit for calculating the amplitude of the video signal that corresponds to the position of the focusing lens detected by the position detector with reference to the correlation table stored in the data recording unit, and an image control unit for adjusting the amplitude of the applied video signal to the amplitude calculated by the processing unit, and supplying the adjusted amplitude to the image forming element.