Abstract: A driving circuit of a plasma display panel is provided in which a display cell including a first electrode and a second electrode is selected to light up, for applying a first voltage Vs1 to the first electrode and a second voltage Vs2 to the second electrode adjacent to the first electrode to cause a sustain discharge between the first and second electrodes. The driving circuit generates a sustain discharge voltage such that, during the sustain discharge between the first and second electrodes, an applied voltage Vc to a third electrode adjacent to the first electrode opposite to the second electrode falls within a range Vs2≦Vc<Vs1, and, in this case, when a display cell including the third electrode is selected to light up, the polarity of a wall charge formed on the third electrode becomes positive.

Abstract: A plasma display panel having a high power efficiency by reducing parasitic capacitances comprises first and second substrates disposed facing each other, a plurality of address lines formed on the first substrate and extending along a first direction and a plurality of X and Y electrodes formed on the second substrate and extending along a second direction crossing the first direction. A first dielectric layer covers the X and Y electrodes formed on the second substrate, the first dielectric layer having a dielectric constant higher than a dielectric constant of the second substrate, and a trench formed at least through the first dielectric layer in an area between two adjacent X and Y electrodes, the trench extending along the second direction.

Abstract: A practical optical waveguide circuit is provided which includes many intersections but is low loss. The width of a waveguide core is w1 at input and output terminal sections and w2 at an intersecting section, where w2>w1. The core width of the intersecting section is made different from that of the input and output terminal sections, or the core height of the intersecting section is made different from that of the input and output terminal sections. The core width is smoothly varied between the intersecting section and the input and output terminal sections by a tapered section. When the number of the waveguides intersecting with the intersecting section is 100, the intersection loss is 5.8 dB for the conventional device where w2=w1=5 &mgr;m, but is 1.8 dB when w2=12 &mgr;m, thereby being able to reduce the intersection loss sharply.

Abstract: A method for driving a plasma display panel applies, within a subfield among the n subfields, a narrow-width pulse having a pulse width equal to or less than 2 &mgr;s to first electrodes in order to cause an erase discharge while terminating a discharge caused between the first and second electrodes, and applies a voltage pulse to third electrodes so that the voltage pulse falls at the same time as the narrow-width pulse falls.

Abstract: A capacitive-load driving circuit has a configuration in which a driving power supply source is connected to an output terminal via a driving device. The capacitive-load driving circuit has a power distributing circuit inserted between the driving power supply source and the driving device. Therefore, temperature rise (power consumption) in the capacitive-load driving circuit can be distributed.

Abstract: A method of driving a plasma display is disclosed, in which the deterioration of the display quality which otherwise might be caused by the light emission due to a reset pulse is prevented thereby to improve the display quality. The voltage of the reset pulse is set taking the voltage due to the accumulated charge into consideration in accordance with a specific display. In this way, the self-erasure discharge is not caused in all the cells but only in the cells involved in display. The display brightness is set also for the self-erasure discharge as a discharge involved in display like the sustaining discharge.

Abstract: A guided-wave optical branching device having optical waveguides disposed on a substrate. The waveguides are partially arranged to be close to each other to form a tapered directional coupler in which the waveguides are point symmetrical or line symmetrical. Alternatively, the waveguides are neither line symmetrical nor point symmetrical. The tapered directional coupler reduces the wavelength dependence of the coupling ratio of the output power derived from the branching device. The widths of the waveguides in the parallel coupling region, the length of the coupling region in the symmetrical or asymmetrical directional coupler, the asymmetrical parameters or the like are set at values determined in accordance with the wavelength range used, so that the wavelength dependence of the coupling ratio of the power between the input port and the output port is reduced in a desired wavelength range, for example, 1.2 .mu.m-1.8 .mu.m.

Abstract: A guided-wave optical branching component is composed of a Mach-Zehnder interferometer having two or more directional couplers. A slight difference .DELTA.L in the optical-path length is provided in two or more optical waveguides connecting the two or more directional couplers. The difference of the optical-path length is less than the shortest wavelength in the operational wavelength region of the guided-wave optical branching component, and the coupling ratio of each of the two directional couplers monotonically increases with wavelength in the operational wavelength region. By using the optical branching components thus constructed (i.e., Mach-Zehnder interferometer type 3-dB optical coupler) in conjunction with a phase shifter, a Mach-Zehnder interferometer type optical switch can be achieved.

Abstract: A recording and reproducing apparatus for a disk-type recording medium including an erase head and a record head which are arranged with a certain rotational angular spacing. The apparatus includes a controller for generating a first signal to operate the erase head and a second signal to operate the record head, and a timing adjusting circuit for delaying either one of the first and second signals to compensate for an error of the angular spacing.

Abstract: Apparatus for reproducing recorded information applies a linearly polarized light beam to a recording medium having first and second recorded information tracks. The recording medium is formed so that the intensity of reflected light relative to the incident light varies in accordance with the information recorded in one of the tracks, and the plane of polarization of the reflected light relative to the linearly polarized incident light varies in accordance with the information recorded in the other track. The reflected light is divided into two components having different planes of polarization. A recorded magnetooptic signal is reproduced from the difference in intensity between the two components, and a recorded light intensity signal is reproduced from at least one of the two components.

Abstract: An apparatus for recording and/or reproducing a signal by using an opto-magnetic disc including an erasing and reproducing opto-magnetic head unit having outer and inner opto-magnetic heads, a recording and reproducing opto-magnetic head unit having outer and inner opto-magnetic heads, a first slider mechanism for moving the erasing and reproducing opto-magnetic head unit in a radial direction of the opto-magnetic disc, and a second slider mechanism for moving the recording and reproducing opto-magnetic head unit in the radial direction of the opto-magnetic disc, the erasing and reproducing opto-magnetic head unit being separated from the recording and reproducing opto-magnetic head unit by substantially 180.degree..

Abstract: In an apparatus for irradiating a magnetooptical recording medium with a linearly polarized light beam and detecting the light from the medium, the light from the magnetooptical recording medium is divided, depending on the degree of the plane of polarization, into two light beams of different intensities which are respectively converted into electrical signals for supply to a differential amplifier, wherein an electrical signal corresponding to a light beam is amplified in order to eliminate the noise component in the output signal of the differential amplifier. In addition, the apparatus is so constructed that the amplification of the electrical signal corresponding to a divided light beam is controlled in response to the electrical signals corresponding to the divided light beams.

Abstract: The invention provides a method for resolving a data packet collision in a local network where a plurality of nodes which respectively comprise processors and terminal equipment utilize a single transmission line in accordance with a contention system.A contention phase is initiated unless a collision occurs. When a collision occurs, a resolution phase is initiated. The nodes which have been performing transmission immediately stop transmission. They discriminate their positions on the transmission line before a time interval (2.times.maximum transmission delay time interval) elapses from the start of transmission. If no signal is received by a given node from the left, the given node is regarded as the leftmost node among the conflicting nodes. The leftmost node immediately starts transmitting a packet. Other nodes except for the leftmost node stop retransmitting the packets. The nodes which have performed retransmission are stopped until the resolution phase is completed.