Hitachi, Ltd.

Hitachi Video Eng. Inc.

Hitachi Video and Information System, Inc.

Junichi Ikoma

Koji Hirata

Masahiko Yatsu

Hidehiro Ikeda

Akio Nakashima

Nobuaki Kabuto

Mitsuo Nakajima

Yoshihisa Ooishi

Mutsumi Suzuki

Toshimitsu Watanabe

Hidenao Kubota

Keizo Shimizu

Tokinori Furuichi

Atsushi Kaneko

Masao Oguri

Nobuo Masuoka

Takashi Kimura

Tetsu Ohishi

Hideaki Ohki

Ryo Hasegawa

Yoshio Miura

Yoshie Kodera

Sadayuki Nishimura

Akinori Maeda

Yoshihisa Hosoe

Nobutaka Ohnuki

Akira Okamoto

Katunobu Takeda

Masahiro Nako

Tatsumi Hasebe

Masayuki Abe

Yasutoshi Nakashima

Kenzi Abiko

The present invention reduces smears arising from voltage decreases caused by the wiring resistance of scan lines for electron emission device selection. The display unit includes an FED panel in which scan lines, data lines, and electron supply devices are positioned at the intersections of the data lines and scan-lines. A scan driver for supplying a selection signal to the scan lines, and a data driver for supplying a drive signal to the data lines are provided. Electron emission devices selected by the selection signal are driven by the drive signal. A signal corrector circuit individually corrects the drive signal to be supplied to each data line to compensate for a voltage decrease caused by the wiring resistance in each column of the scan lines.

Display unit

A back substrate has a plurality of electron emission elements. A display substrate comprises an optically transparent substrate disposed opposite to the back substrate; an accelerating electrode formed on the inner face of the optically transparent substrate for accelerating electron beams emitted from the electron emission elements; and luminescent materials excited by the electron beams to emit light toward the outer face of the optically transparent substrate. A frame member supports the back substrate and display substrate on their peripheries. A vacuum chamber is defined by the back substrate, display substrate, and frame member. A conductor electrically connected to the accelerating electrode is drawn out to the outside of the vacuum chamber. A high voltage connector for supplying an accelerating voltage to the conductor is removably connected to the conductor.

Display device

To improve luminance uniformity in a panel plane, for example, there is set an amplitude of a pixel driving voltage which is an anode current in the neighborhood of a threshold value of electron emission of one pixel and the amplitude is kept as a threshold value correction value for each pixel, and to correct the luminance variation in the high-luminance emission between the pixels, there is set an amplitude of a pixel driving voltage which is an anode current in the neighborhood of a maximum value of electron emission of one pixel and the amplitude is kept as a gain correction value for each pixel. In the configuration, when a video image is displayed, the input video signal is corrected using the threshold correction value and the gain correction value for each pixel.

Display device having luminance correcting function

A projection type image display apparatus having an image display element outputting an image ray, a projection lens apparatus for performing overhead projection of the image ray from the image display element, the projection lens apparatus having a plurality of lens elements, a reflection mirror reflecting the image ray from the projection lens apparatus, and a screen on which the image ray reflected by the reflection mirror is projected.

Projection lens apparatus and projection type image display apparatus

A projection type image display apparatus having an image display element outputting an image ray, a projection lens apparatus for performing overhead projection of the image ray from the image display element, the projection lens apparatus having a plurality of lens elements, a reflection mirror reflecting the image ray from the projection lens apparatus, and a screen on which the image ray reflected by the reflection mirror is projected. An optical axis of the projection lens apparatus is decentered from a center of the screen.

An image display device for displaying images by using the digital signal processing and by making use of the sight emission of the phosphor. An static image is detected from an image signal data, and when the luminance level of the static image is high, the luminance level of the specific area is lowered, and when the luminance level of the static image is low, the luminance level of the specific area is increased. In this manner, it is possible to reduce image retention of the static image when the static image is displayed for a long time.

Image display device and method of displaying images with static image detection

A color display apparatus for a video information system includes an input for receiving at least one externally applied color component signal, a display device having predetermined color characteristics, and a compensating unit responsive to the at least one externally applied color component signal from the input for compensating at least a portion of the at least one externally applied color component signal in accordance with the predetermined color characteristics of the display device. The display device is responsive to the input and the compensating unit for displaying a color image of the externally applied color component signal.

Color display apparatus having compensating unit

There is provided the construction of a multiprojection apparatus composed of a plurality of projection units arranged in the vertical and horizontal directions, in which a transparent holding strip having an H-shaped cross section is inserted between screens each composed of a lenticular sheet and a Fresnel lens, and the right and left ends of a multiscreen are supported by elastic support members, or in which a receive member for receiving the screen in the direction of the optical axis and a screen holding device are provided, the receive member has such a shape as not to block projection light corresponding to an image on the screen and is located near a joint of the screen and another screen, and the holding device is disposed on a black stripe of the lenticular sheet and always pulled by an elastic member toward the receive member. Therefore, according to the present invention, it is possible to restrict the missing of information due to joints of the screens.

Multiprojection apparatus

A light emitted from a laser diode is reflected by a video disc which is rotated by a spindle motor. The reflected light is modulated by video information recorded on the video disc and converted to an electrical signal by a photodiode array. A signal generated by a trapezoidal generator is sampled with a horizontal synchronizing signal separated from the video information signal. The sampled signal is supplied to the spindle motor for correcting a time base error. A zero crossing point of the trapezoidal waveform is detected and is utilized for controlling the start of a rise portion of the trapezoidal waveform for compensating a DC offset. The trapezoidal waveform is controlled so as to vary an average power supplied to the spindle motor in accordance with a detected rotational speed difference so as to compensate a rotational speed of the spindle motor.

System for correcting time base error of information reproducing

In an apparatus for reproducing information recorded on a disk having a tracking servo device for an actuator which directs a read beam to a track of the disk, a first power product is applied to the actuator upon turn-off of the tracking servo system, a velocity of the actuator is detected based on an error signal from the tracking servo device, the velocity of the actuator detected immediately after the start of movement of the actuator is stored, on the basis of the detected result, the subsequent velocity of the actuator is sequentially compared with the initial velocity and the velocity is controlled at a constant value until the actuator reaches a predetermined track.

Apparatus for reproducing information recorded on a disk

A disc positioning device for positioning a disc having a center opening with respect to a spindle for driving the disc for rotation by bringing the center axes thereof into alignment with each other. An adapter in the form of a hemispherical body of a diameter greater than that of the center opening of the disc is mounted on the spindle in such a manner that the center of a spherical body from which the hemispherical body of the adapter is severed coincides with the center axis of the spindle at all times. The adapter is urged by a spring to be biased with the center thereof serving as the center of rotation.

Disc positioning device

A skip/arm servo system for a video disc player comprises a device adapted to skip a signal sensing element, such as a stylus for detection of information recorded on a disc, in a direction crossing a recording track, a stylus position detector adapted to detect the relative position of the stylus to a cartridge movably mounting the stylus, a comparator comparing the detected relative position with a reference relative position to produce an error output, a cartridge driver responsive to the error output to move the cartridge so as to maintain the stylus in the reference relative position. A setting device is adapted to variably set the reference relative position in accordance with a reproduction mode selected by the operator, whereby a special mode reproduction can readily be accomplished or the stylus can be readily released from a locked groove in the disc.

Skip/arm servo system for a video disc player

A frequency detector comprising first, second and third conductive patterns. The first conductive pattern includes an even number of first straight conductive pieces which are disposed radially at regular intervals and sequentially connected in series alternately through first inner periphery conductive pieces and first outer periphery conductive pieces. The second conductive pattern includes an even number of second straight conductive pieces disposed radially at predetermined intervals between the adjacent two first straight conductive pieces at the outer periphery sides of the respective first inner periphery conductive pieces and connected in series. The third conductive pattern includes an even number of third straight conductive pieces disposed radially at predetermined intervals between the adjacent two first straight conductive pattern at the inner periphery sides of the respective first outer periphery conductive piece and connected in series. A first and a second terminal are provided at both ends of the first conductive pattern. The first, second and third conductive patterns are connected in series between the first terminal and a third terminal provided at an end of the second or third conductive pattern.

Frequency detector

A stylus position detecting apparatus in use for a video disc player using a disc of the groove type, detecting plates for detecting leakage components of a high frequency signal supplied from a high frequency signal source and flowing through a flylead, and for reading out a recorded signal in a disc are provided on both sides of the flylead. The leakage signal components detected by the detecting plates are detected to positive and negative directions with respect to a reference voltage. These voltages obtained by the detections are added by an adder, to find a stylus position.

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Yokosuka, Japan

Junichi Ikoma