Abstract: A temperature control device for controlling temperature variable devices disposed near a grating of a variable dispersion equalizer including an optical waveguide having the grating. The temperature variable devices control temperatures independently of each other. The temperature control device includes a controller for controlling the temperature variable units, and a storage device which stores temperature control patterns including combinations of control signals for the respective temperature variable units. The controller controls the temperature variable devices with a control signal of at least one of the temperature control patterns selected from the storage device.

Abstract: In a polarization mode dispersion compensating apparatus for controlling polarization mode dispersion of an optical signal, a first optical monitor detects and outputs, based on an optical signal outputted from a first optical transmission line having a grating, a first detection signal indicating magnitude of waveform distortion thereof, and a second optical monitor detects and outputs, based on an optical signal outputted from a second optical transmission line having a grating, a second detection signal indicating magnitude of waveform distortion thereof: A calculator circuit performs a predetermined calculation about the first and second detection signals, and outputs an output signal indicating a result of the calculation. A controller controls a polarization controller based on the output signal from the calculator circuit.

Abstract: A variable dispersion compensator comprises a substrate, a fiber grating, and a plurality of heater elements. Main heater elements are arranged in a grating range of the fiber grating. A sub-heater element is arranged within the grating range of the fiber grating. Heat from the sub-heater element is used to correct a temperature distribution produced by the main heater elements in the fiber grating to achieve a linear temperature distribution.

Abstract: An optical dispersion compensator comprises a heater unit for heating a fiber grating, a heater controller and a Peltier controller. The fiber grating heater unit includes heater elements formed in line on a quartz substrate and a fiber grating arranged on the heater elements. The fiber grating is secured on the quartz substrate using a cap. A step is formed in the quartz substrate to position the cap relative to the heater elements. The fiber grating is inserted into a groove in the cap to position the fiber grating relative to the heater elements.

Abstract: A waveguide grating device controlling Bragg wavelength after manufacture of the device includes an optical waveguide on a substrate. A variable stress is applied to a waveguide grating in part of the waveguide to bend at least the portion of the substrate including the waveguide grating, changing the Bragg wavelength.

Abstract: A backlight provides uniform emanating light for a liquid crystal display. In the backlight, light emitted from a light source is incident on a receiving end surface of a light guide plate and emanates through a top surface toward a liquid crystal panel. A bottom surface includes a reflecting hollow wedge extending along the receiving end surface and varying in depth, as measured from the bottom surface, in correspondence with distance from the end surface. A dividing flat portion orthogonal to the reflecting hollow wedge divides the reflecting hollowed portion, and an output surface includes a prism having parallel ridges extending in a direction orthogonal to the receiving end surface.

Abstract: This invention provides a temperature control device for controlling a plurality of temperature variable devices disposed near a grating of a variable dispersion equalizer including an optical waveguide having the grating. The temperature variable devices are able to control the temperatures independently of each other. The temperature control device includes a controller for controlling the temperature variable units, and a storage device which stores a plurality of temperature control patterns includes combinations of control signals of the respective temperature variable units. The controller controls the temperature variable devices by a control signal of at least one of the temperature control patterns selected from the storage device.

Abstract: A method of manufacturing a grating in an optical waveguide that includes a core and a cladding covering the core. The method includes the steps of providing the optical waveguide and scanning a laser beam along an optical axis of the optical waveguide to form modulation of refractive index of radiation in the core. The core is made of a material having the refractive index that is changeable by irradiation of radiation. In addition, on the step of scanning, in the core, the irradiation range of the laser beam is controlled and the laser beam is scanned a plurality of times. Therefore, predetermined distribution of irradiation amount is obtained in a direction of the optical axis of the grating.

Abstract: A liquid crystal panel module includes a liquid crystal panel unit on a backlight unit. The backlight unit preferably has a holding member for holding the liquid crystal panel unit in a specific position on the backlight unit with no gap therebetween. Preferably, the backlight unit comprises a light guide; a lamp for emitting illumination from one side of the light guide; and a reflector for collecting light from the lamp on the light guide. The reflector has a polygonal cross section, a thickness greater than the thickness of the light guide, and is open to only the thickness of the light guide on the light guide side of the reflector.

Abstract: A display panel with a reduced capacitive coupling. The panel includes a transmission type liquid crystal panel. A lamp is provided adjacent at least one side of a light guide plate to guide the light to the crystal panel. A high frequency current supply is used to power the light. A reflective plate encircles the lamp so as to introduce the light to the light guide plate. A housing is made of a thin metal plate. Each portion of the housing is connected with a common electrical potential. Part of the housing extends away from the reflective plate around the lamp or contains an opening in the same location. By this arrangement, the capacitance between the reflective plate and the housing is made smaller thus reducing the leakage current.

Abstract: A method of driving a plasma display panel for generating picture or image with high quality while suppressing luminance to a low level in the display in black. One field for image display is composed of at least two different types of subfields first and second subfields.

Abstract: In the gas discharge image display of this invention, the peak value of a write pulse supplied to one of two electrodes of each of fluorescent lamps aligned in a matrix form is substantially equal to the peak value of a sustain pulse supplied to that electrode. Therefore, when a row line drive circuit or a column line drive circuit supplies, in a sustain period of a fluorescent lamp to be discharged, a write pulse to another fluorescent lamp aligned in the same row or column of the matrix form, a voltage at the fluorescent lamp to be discharged can be made constant in the sustain period.

Abstract: The present invention provides a rare gas discharge fluorescent lamp device which is long in life and high in brightness and efficiency. The lamp device basically comprises a rare gas discharge fluorescent lamp wherein rare gas is enclosed in the inside of a glass bulb which has a fluorescent layer formed on an inner face thereof and has a pair of electrodes at the opposite ends thereof. In one embodiment, it further comprises a dc power source and a resonance circuit for generating pulse-like voltage across the pair of electrodes having the time rate of energization time to a period higher than 5% but lower than 70% and the energization time within a period shorter than 150 .mu.

Abstract: A display fluorescent lamp comprises; a dielectric cylindrical container having a large-diameter portion in which rare gas is sealed and a small-diameter portion which is almost coaxially connected with the large-diameter portion at one end of the large-diameter portion, the outside diameter thereof being smaller than that of the large-diameter portion; a light emitting portion which is formed at the other end of the large-diameter portion and has permeability; an internal electrode which is inserted into the cylindrical container from the other end of the small-diameter portion which is not connected with the large-diameter portion; a fluorescent substance layer formed on the inside face excluding that in which the light emitting portion is formed, of the large-diameter portion of the cylindrical container; and an external electrode formed on the outside face of the large-diameter portion excluding a portion in which the light emitting portion of the cylindrical container is formed, the length in the axial d

Abstract: A discharge lamp having a large light output and a stable discharge. On an external surface of a cylindrical glass bulb enclosing a rare gas such as xenon, a pair of beltlike electrodes are mounted so as to face each other. A light output part is provided between the electrodes, and the electrodes are situated close to each other on the opposite side to the light output part. An image display device is constituted by arranging a plurality of the discharge lamps.

Abstract: A gas discharge image display is formed by disposing a plurality of fluorescent lamps 1 each comprising a glass bulb 2 within which a rare gas is sealed, one or more pairs of external electrodes 5a and 5b located on the outer wall of the glass bulb 2, and a fluorescent layer 3 formed on the inner wall of the container facing the external electrodes 5a and 5b. An alternating voltage pulse is applied between the paired external electrodes 5a and 5b by an X drive circuit 9 and a Y drive circuit 10 for discharge light emission, thereby displaying an image. The pressure and alternating voltage in the fluorescent lamp 1 are changed in response to the type of fluorescent material, thereby making near light emission and discharge characteristics of the discharge lamps which differ in electric characteristics.

Abstract: A surface luminous lighting unit has a light panel comprising a plurality of light guiding plates laminated in different lengths. The longer side of the light panel is made shorter than the distance between filaments of a lamp, and longer than the distance between the portions where a luminance of the lamp is equal to 75% of the maximum luminance of the lamp. The surface luminous lighting unit comprises a light guide which comprises a plurality of light guiding plates in different length laminated in such a manner that the sides of those plates where light enters are made level with each other, where the other sides thereof are arranged in a step-like. A linear light source is affixed to the light entering side of the light guide, and a reflector is affixed to the light exiting side of the light guide in such a manner as to extend thereover.

Abstract: The present invention provides a rare gas discharge fluorescent lamp device which is long in life and high in brightness and efficiency. The lamp device basically comprises a rare gas discharge fluroescent lamp wherein rare gas is enclosed in the inside of a glass bulb which has a fluorescent layer formed on an inner face thereof and has a pair of electrodes at the opposite ends thereof. In one embodiment, it further comprises a dc power source and a resonance circuit for generating pulse-like voltage across the pair of electrodes having the time rate of energization time to a period higher than 5% but lower than 70% and the energization time within a period shorter than 150 .mu.