Citizen Watch Company, Ltd.

Citizen Holdings Company, Ltd.

Shinya Kondoh

Shigekazu Takahashi

Mie Ohara

Akira Suguro

Haruki Amakawa

Toshiaki Fukushima

Takashi Ihara

Rintarou Takahashi

Yuuji Yano

A drive circuit has a ferroelectric liquid crystal panel that operates at a given switching angle and response speed, a sensor that measures temperature, a drive circuit that supplies driving voltage to the ferroelectric liquid crystal panel, a waveform generation circuit that supplies a waveform signal to the drive circuit, and a control circuit that controls the waveform generation circuit; and in a first frame of the driving voltage, outputs during a first interval, a first voltage that is positive and outputs during a second interval that is longer than the first interval, a second voltage that is positive, and in a second frame, outputs during the first interval, the first voltage that is negative and outputs during the second interval that is longer than the first interval, the second voltage that is negative. The control circuit varies the first voltage and the second voltage according to the measured temperature.

Liquid crystal apparatus

In a liquid-crystal-display panel () for displaying a barcode that is formed with bars having various widths arranged in parallel at various intervals by an electro-optic effect of liquid crystal, a direction of a transmissive axis (P) of a polarizing film disposed on a side on which light from a barcode reader is irradiated is set to coincides with a direction in which the light is polarized. Moreover, the direction of transmissive axis (P) of the polarizing film is set to be parallel or substantially parallel to a short side or a long side of each of the bars forming the barcode. A direction (M) of a long axis of a liquid crystal molecule (LCM) in a first ferroelectric state or in a second ferroelectric state is set to be parallel or substantially parallel to the direction of transmissive axis (P) of the polarizing film, or set to form an angel of 45 degrees or substantially 45 degrees therebetween.

Liquid-crystal-display panel and barcode reading system using the same

An object of the present invention is to provide a memory-type liquid crystal display device capable of controlling a color to be displayed in a peripheral area without using display data based on which display is achieved in the peripheral area. The memory-type liquid crystal display device having a display area and a peripheral area located on the perimeter of the display area, comprising a memory-type liquid crystal provided between first and second substrates and has a first stable state and a second stable state, a first pixel disposed on the display area, a second pixel disposed on the peripheral area and a control unit that applies a reset pulse to a portion of the memory-type liquid crystal corresponding to the first and second pixel so that the portion of the memory-type liquid crystal corresponding to the first and second pixels becomes one of the first and second stable states at a reset period which resets a state of the memory-type liquid crystal, and controls the memory-type liquid crystal so that a portion of the memory-type liquid crystal corresponding to the second pixel maintains its stable state of the reset period at a frame period after the reset period.

Memory-type liquid crystal display device

The liquid crystal display apparatus according to the present invention includes a first substrate, a second substrate, a reflective polarizer, mounted on the first substrate and having a first transmission axis and a first reflection axis at right angles to each other, for transmitting linearly polarized light vibrating in a plane parallel to the first transmission axis and for reflecting linearly polarized light vibrating in a plane parallel to the first reflection axis, a polarizer, mounted on the second substrate and having a second transmission axis, for transmitting linearly polarized light vibrating in a plane parallel to the second transmission axis, and a liquid crystal layer, provided between the first and second substrates, having a first mode which causes the direction of polarization of incident light to change by utilizing birefringence and a second mode which does not utilize birefringence and therefore does not cause the direction of polarization of incident light to change, wherein a display state is switched between a bright display state and a dark display state by applying a voltage to the liquid crystal layer, and the bright display state is produced by driving the liquid crystal layer in the second mode.

Liquid crystal display apparatus

A substrate for a liquid crystal panel having an alignment film, wherein an evaporated film is formed as the alignment film on the substrate, and wherein a portion of the evaporated film corresponding to each single pixel is split into a plurality of segments, and the evaporated film is formed with a different evaporation angle on each of the segments. The evaporation angle &#x3b8; which is different for each of the plurality of segments is set within a range of 80&#xb0;&#x2266;&#x3b8;&#x2266;88&#xb0; with respect to the layer normal to the substrate, and the plurality of split segments have approximately equal areas.

Liquid crystal panel substrate having alignment film and method for forming alignment film by varied evaporation angle

An antiferroelectric liquid crystal display comprises: an antiferroelectric liquid crystal display element which includes an antiferroelectric liquid crystal that is sandwiched between a pair of substrates having a plurality of scanning electrodes and signal electrodes deposited respectively on the opposing surfaces thereof; and a light source which successively emits a plurality of different colors of light. In the thus constructed antiferroelectric liquid crystal display, a scanning period (TS) during which the light source emits light of one of the plurality of colors is divided into two periods, of which the first period (SC) includes a selection period for determining a display state and a non-selection period for holding therethrough the display state selected during the selection period, and the second period (SC), constituting the remainder of the scanning period, includes a selection period for forcing the display state into a black display state and a non-selection period for holding therethrough the black display state selected during the selection period.

Liquid crystal display and method of driving the same

An antiferroelectric liquid crystal panel, having an antiferroelectric liquid crystal between a pair of substrates, which comprises a driving circuit adapted to output a layer structure controlling voltage waveform having a frequency of 1 Hz to 100 Hz and a voltage in the range of +10 V to +50 V or &#x2212;10 V to &#x2212;50 V, for an optional length of time.

Antiferroelectric liquid crystal display and method of driving the same

Disclosed is a liquid crystal optical device which produces a color display by using a light source mounted behind a liquid crystal panel and capable of emitting a plurality of different colors, wherein the period from the time the light source mounted on the back emits one color to the time the light source switches to the next color is set as a scanning period, and the scanning period comprises a selection period (Se), a non-selection period (NSe), and a reset period (Rs), the length of the reset period being equal to one half the scanning period, and wherein a black display state is effected in the reset period (Rs).

Liquid crystal optical device

Disclosed is a liquid crystal shutter that uses as a shutter a liquid crystal panel constructed by sandwiching DHF liquid crystal between a pair of substrates provided with one or more pixel electrodes and one or more counter electrodes, wherein a driving waveform for the panel has a write period comprising two subfields. In each of the subfields, a single pulse is applied to a pixel, the single pulse applied in one subfield being opposite in polarity to the single pulse applied in the other subfield. On the other hand, a constant voltage of 0 V or close to 0 V is applied to the pixel during a period in which neither of the single pulses is applied.

Liquid crystal shutter

The invention relates to a ferroelectric liquid crystal display in which the trailing phenomenon is eliminated by providing an optimum reset period. The ferroelectric liquid crystal display has a reset period for resetting the ferroelectric liquid crystal to a black display state before starting the scanning period, and includes a mechanism for adjusting the length of the reset period in accordance with the display data, thus setting an optimum reset period corresponding to the display data. The reset period is provided for each pixel. Also, the reset period can be provided at the same timing so that all the pixels may be reset at the same time. The ferroelectric liquid crystal panel includes a backlight, which is turned off during the reset period and turned on during the remaining period. A mechanism is provided for adjusting the brightness of the backlight in accordance with the length of the reset period.

Ferroelectric liquid crystal display

An antiferroelectric liquid crystal display, which is equipped with an antiferroelectric liquid crystal panel having an antiferroelectric liquid crystal sandwiched between a pair of substrates, performs at least one scanning period when carrying out a display based on one set of display data, wherein the scanning period comprises a selection period for determining the state of the antiferroelectric liquid crystal, a non-selection period for holding the state determined in the selection period, and a reset period for resetting pixels to a black display state before initiating the selection period. The length of the reset period is adjusted according to the speed of change in the display data. Alternatively, the pixels are reset to a white display state in the reset period and, during that period, the backlight is turned off.

Antiferroelectric liquid crystal display

A ferroelectric liquid crystal display element holds a ferroelectric liquid crystal between a pair of substrates. A driving scheme includes a reset period having a switching period and a non-switching period which precede application of a selection pulse. During the switching period, a voltage exceeding a threshold voltage required to switch the ferroelectric liquid crystal is applied irrespective of the display data to be written to a pixel, and during the non-switching period, an ion electric field in the ferroelectric liquid crystal is aligned in such a direction that cancels the direction of an electric field produced by spontaneous polarization of the liquid crystal molecules. A voltage not exceeding the threshold voltage of the ferroelectric liquid crystal, preferably a voltage of 0 V, that is, no voltage, is applied during the non-switching period.

Ferroelectric liquid crystal device and driving method to prevent threshold voltage change

A ferroelectric liquid crystal display comprises: a ferroelectric liquid crystal display element which includes a ferroelectric liquid crystal that is sandwiched between a pair of substrates having a plurality of scanning electrodes and signal electrodes deposited respectively on the opposing surfaces thereof; and a light source which successively emits a plurality of different colors of light. In the thus constructed ferroelectric liquid crystal display, a scanning period (TS) during which the light source emits light of one of the plurality of colors is divided into two periods, of which the first period (SC ) includes a selection period for determining a display state and a non-selection period for holding therethrough the display state selected during the selection period, and the second period (SC ), constituting the remainder of the scanning period, includes a selection period for forcing the display state into a black display state and a non-selection period for holding therethrough the black display state selected during the selection period.

Ferroelectric liquid crystal display and method of driving the same

An antiferroelectric liquid crystal display comprises: an antiferroelectric liquid crystal display element which includes an antiferroelectric liquid crystal that is sandwiched between a pair of substrates having a plurality of scanning electrodes and signal electrodes deposited respectively on the opposing surfaces thereof; and a light source which successively emits a plurality of different colors of light. In the thus constructed antiferroelectric liquid crystal display, a scanning period (TS) during which the light source emits light of one of the plurality of colors is divided into two periods, of which the first period (SC ) includes a selection period for determining a display state and a non-selection period for holding therethrough the display state selected during the selection period, and the second period (SC ), constituting the remainder of the scanning period, includes a selection period for forcing the display state into a black display state and a non-selection period for holding therethrough the black display state selected during the selection period.

Growing community of inventors

Nishitokyo, Japan

Shinya Kondoh