Other

Hitachi, Ltd.

Canon Kabushiki Kaisha

Japan Display Inc.

Hitachi Displays, Ltd.

Hitachi Video and Information Systems, Inc.

Masahisa Tsukahara

Toshimitsu Watanabe

Kazuhiko Yoshizawa

Yukimi Saiki

Nobuaki Kabuto

Hiroyuki Nitta

Takeshi Mochizuki

Toshifumi Ozaki

Makoto Kitamura

Hajime Akimoto

Naruhiko Kasai

Shoji Yamamoto

Norihiro Nakamura

Junichi Yokoyama

Takahiro Ichikawa

Provided is an image display device including: a pixel circuit; a power supply line; a data line for supplying a data signal to the pixel circuit; and a current path control unit. The pixel circuit includes: a light emitting element; a drive transistor for controlling a current flowing to the light emitting element; a storage capacitor provided between the data line and a gate electrode of the drive transistor, for storing a potential difference; and a data line connection switch for connecting one end of the storage capacitor on the gate electrode side of the drive transistor and the data line. Before the data line supplies the data signal, the data line connection switch is turned ON, and the current path control unit interrupts a current path from the power supply line to the one end of the storage capacitor.

Image display device

An image display device includes: a first power supply line; a second power supply line; a plurality of pixel circuit; a driving circuit for supplying a data signal and a scanning signal; and a switch unit. Each pixel circuit includes: a driving transistor between the first power supply line and the second power supply line; a light emitting element controlled by the driving transistor; and a storage capacitor for storing the data signal and controlling the driving transistor. The driving circuit causes the storage capacitor to store the data signal and controls an intensity of light emission based on the data signal. The switch unit is provided at one of one end of the first power supply line and one end of the second power supply line to control whether or not to allow a current to flow from the first power supply line to the second power supply line.

Scan electrode potential detected by a feedback switch is inputted into a negative-phase input terminal of an amplifier, reference selection potential from a reference-selection-potential-signal generation circuit is inputted into a positive-phase input terminal of the amplifier, and the reference-selection-potential-signal generation circuit delays reference potential of a reference voltage source, thereby scan electrode potential without overshooting components can be achieved.

Display device and driving method of the same

A display device driver constructed of scanning selection switches corresponding to a plurality of scanning wiring lines, a non-selection switch which brings the scanning wiring line into a non-selected state, a feedback switch which detects a scanning electrode potential and a negative feedback amplifier which sets the scanning electrode potential to a predetermined potential every electrode based on the scanning electrode potential detected by the feedback switch, and a time constant formed of a combined capacitance of a capacitance of the feedback switch and a wiring line capacitance and a feedback switch resistance is set to be smaller than that of a display panel capacitance and a scanning selection switch resistance.

Display device and method for driving a display device

A high definition display unit which demodulates, decodes, and processes in relation to chroma and displays a television signal in which a PI (picture) signal and an SI (service information) signal are mixed. A changeover switch connected to an image quality adjusting circuit in a video chroma processing circuit is opened or closed according to an on-off signal S showing the superposed period of both signals detected by a decoder . If the above on-off signal S is on, the changeover switch is opened and the adjustment of image quality is disabled. Therefore, SI display never disappears due to the adjustment of image quality, and the quality of an image can be also adjusted according to an ambient status. Other approaches are also disclosed from preventing image quality adjustment of at least portions of a displayed image containing an information image.

High definition display unit and high definition display method

A high definition display unit which demodulates, decodes, and processes in relation to chroma and displays a television signal in which a PI (picture) signal and an SI (service information) signal are mixed. A changeover switch connected to an image quality adjusting circuit in a video chroma processing circuit is opened or closed according to an on-off signal S showing the superposed period of both signals detected by a decoder If the above on-off signal S is on, the changeover switch is opened and the adjustment of image quality is disabled. Therefore, SI display never disappears due to the adjustment of image quality, and the quality of an image can be also adjusted according to an ambient status. Other approaches are also disclosed from preventing image quality adjustment of at least portions of a displayed image containing an information image.

A digital television signal receiver includes a decoder, capable of decoding digital television signals having a plurality of different formats, which outputs video information in which image fields having mutually different numbers of scanning lines appear aperiodically when the decoder decodes a digital television signal having a specific one of the different formats; a display device which displays an image based on the video information output from the decoder; and an image controller which sets respective display start positions for the image fields having mutually different numbers of scanning lines to a same display start position in a vertical direction when the display device displays an image based on the video information output from the decoder when the decoder decodes the digital television signal having the specific format.

Display device also compatible with digital broadcasts

When a video signal is double-speed processed by the first device, a slight vertical deflection process is performed for redundant similar scan lines by the second device, and any slight deflection in the second device is controlled by the first device to enable setting so as to display images with excellent resolution. The first device generates a discrimination signal to designate interlaced scanning and flag a need for vertical scan-line deflection, and such signal is provided to the second device such that the second device can always appropriately determine need for vertical scan-line deflection. Through monitoring for the discrimination signal, an image display apparatus can prevent vertical resolution from deteriorating when video signals possibly requiring vertical line-shifting are inputted from an external source, and can prevent vertical resolution from deteriorating when displaying images of video signals having different systems within different areas on the same screen.

Image display apparatus and personal computer for displaying personal computer signals and broadcast signals

A high definition display unit which demodulates, decodes, and processes in relation to chroma and displays a television signal in which a PI (picture) signal and an SI (service information) signal are mixed. A changeover switch connected to an image quality adjusting circuit in a video chroma processing circuit is opened or closed according to an on-off signal S , showing the superposed period of both signals detected by a decoder . If the above on-off signal S is on, the changeover switch is opened and the adjustment of image quality is disabled. Therefore, SI display never disappears due to the adjustment of image quality, and the quality of an image can be also adjusted according to an ambient status. Other approaches are also disclosed from preventing image quality adjustment of at least portions of a displayed image containing an information image.

Image display apparatus, and method to prevent or limit user adjustment of displayed image quality

A display device which displays an image on a cathode-ray tube screen based on video information decoded from a signal-compressed digital broadcast signal. The video information contains fields having a number of scanning lines which may change from field to field, potentially causing vertical jitter in the displayed image. A circuit prevents the vertical jitter by setting a same vertical scanning start position of an electron beam on the screen for all of the fields regardless of the number of scanning lines. The circuit may be a clamp circuit which clamps a vertical ramp waveform; or a control circuit which controls a direct current level of the vertical ramp waveform when the number of scanning lines in a current field is different from a reference number of scanning lines; or an amplitude control circuit which performs feedback control of an amplitude of the vertical ramp waveform.

When a video signal is double-speed processed by the first device, a slight vertical deflection process is performed for redundant similar scan lines by the second device, and any slight deflection in the second device is controlled by the first device to thereby enable setting so as to always display images with excellent resolution. More particularly, a discrimination signal is generated by the first device to designate interlaced scanning and flag a need for vertical scan-line deflection, and such discrimination signal is provided to the second device such that the second device can always appropriately determine the need for vertical scan-line deflection. Through monitoring for the discrimination signal, an image display apparatus is capable of preventing vertical resolution from being deteriorated when video signals possibly requiring vertical line-shifting are inputted from an external source. Further, an image display apparatus is capable of preventing the vertical resolution from being deteriorated when images of video signals having different systems are displayed within different areas on a same screen.

A raster distortion correction and deflection circuit arrangement includes a deflection coil adapted to be mounted on a cathode ray tube, a horizontal deflection coil driving circuit for passing a current of saw-tooth waveform of a horizontal deflection period through a horizontal deflection coil constituting the deflection coil, a flyback transformer the primary winding of which is connected between a power supply and an output terminal of the horizontal deflection coil driving circuit, an S-correction capacitor connected in series with the horizontal deflection coil, and an anode voltage detection circuit for detecting variations in an anode voltage of the cathode ray tube which is a secondary winding output of the flyback transformer. A raster distortion correction current based on an output voltage of the anode voltage detection circuit is injected into a connection point of the horizontal deflection coil and the S-correction capacitor. A signal from a signal detection circuit for ABL connected to the flyback transformer can be employed together with an output of the anode voltage detection circuit or in substitution for it for generating the raster distortion correction current.

Raster distortion correction and deflection circuit arrangement

A display device for suppressing focus dislocation due to high voltage fluctuation and realizing a dynamic focus circuit with large output at low power consumption and low cost, in which a circuit for detecting high voltage fluctuation is provided, and the dynamic focus waveform is clamped, and the waveform of horizontal cycle is clipped during the retrace time, and a boot strap circuit including an emitter follower, DC feedback circuit, and capacitor is provided as an output circuit.

Growing community of inventors

Fujisawa, Japan

Masahisa Tsukahara