Abstract: To develop optical discs stored while being stacked and to load them to a plurality of recording/reproducing devices simultaneously. Trays for mounting optical discs are stacked to configure an optical disc transportation body, and the portions being exposed without overlapping when the stacked trays are viewed from the stacking direction are utilized as tray operation portions for handling. Supporting portions abutting against the tray operation portions inherent to respective trays in one to one correspondence are fixed with an interval in the vertical direction to the frames configuring a tray distributing/holding portion. The tray operation portion of each tray is held by the supporting portion at each position by moving the optical disc transportation body downward along the frames, and intervals corresponding to the arrangement pitch of recording/reproducing devices are formed between respective trays.

Abstract: A semiconductor laser device has a semiconductor laser diode structure made of group III nitride semiconductors having major growth surfaces defined by nonpolar planes or semipolar planes. The semiconductor laser diode structure includes a p-type cladding layer and an n-type cladding layer, a p-type guide layer and an n-type guide layer held between the p-type cladding layer and the n-type cladding layer, and an active layer containing In held between the p-type guide layer and the n-type guide layer. The In compositions in the p-type guide layer and the n-type guide layer are increased as approaching the active layer respectively. Each of the p-type guide layer and the n-type guide layer may have a plurality of InxGa1-xN layers (0?x?1). In this case, the plurality of InxGa1-xN layers may be stacked in such order that the In compositions therein are increased as approaching the active layer.

Abstract: A semiconductor laser device is made of a group III nitride semiconductor having a major growth surface defined by a nonpolar plane or a semipolar plane. The semiconductor laser device includes a cavity having an active layer containing In and distributed Bragg reflectors coating both cavity end faces of the cavity respectively. In each of the distributed Bragg reflectors, a central wavelength ?c of a reflectance spectrum satisfies the relation ?SP?10 nm??c??SP+10 nm with respect to an emission peak wavelength ?SP of spontaneous emission in the active layer.

Abstract: A position-error-signal calculation circuit (105) calculates a relative position error between a laser-focused-beam spot (103) and an information recording layer (102), and generates a focus error signal (106). A filter (108) amplifies and passes therethrough a signal component in the vicinity of the natural resonance frequency of at least one mode among the natural vibration modes of the optical disc medium (101). A drive amplifier receives through a stabilizing compensator (109) and a D/A converter (110) the focus error signal (106) passed by the filter (108), to drive an objective lens (113), thereby allowing the laser-focused-beam spot (103) to track the information recording layer (102).

Abstract: A semiconductor light emitting device is made of a group III nitride semiconductor having a major growth surface defined by a nonpolar plane or a semipolar plane, and has a quantum well layer containing In in a light emitting layer. A strain compensation layer made of a group III nitride semiconductor containing Al and having a lattice constant smaller than the lattice constant of the quantum well layer in a strain-free state is interposed in the light emitting layer of a quantum well structure having the quantum well layer and a barrier layer or in an adjacent layer adjacent to the light emitting layer.

Abstract: A nitride semiconductor laser diode has a quantum well layer consisting of a mixed crystal of Alx1Iny1Ga1-x1-y1N (x1?0.5, y1?0 and 1?x1?y1?0.5) in a group III nitride semiconductor multilayer structure having a major growth surface defined by a nonpolar plane. A cavity direction of the laser diode is perpendicular to a c-axis. The major growth surface of the group III nitride semiconductor multilayer structure may be defined by an m-plane. In this case, the cavity direction may be along an a-axis.

Abstract: Optical information recording and reproducing medium 10 has two recording layers of first and second recording layers 12 and 14, from a laser beam incident surface side. In each control area 21, recording layer management information containing at least information indicating recording states of a plurality of areas into which the inside of data recording area 22 of each recording layer is divided is recorded. When recording or reproducing is performed on the second recording layer 14, the recording layer management information is checked, and a laser beam output is changed based on a recording state of an area corresponding to the first recording layer 12.

Abstract: This semiconductor light emitting device includes an optical cavity made of a group III nitride semiconductor having a major growth surface defined by a nonpolar plane and including a pair of cavity end faces parallel to c-planes, and a reflecting portion made of a group III nitride semiconductor having a major growth surface defined by a nonpolar plane and having a reflective facet opposed to one of the pair of cavity end faces and inclined with respect to a normal of the major growth surface. The optical cavity and the reflecting portion may be crystal-grown from the major surface of the substrate. The substrate is preferably a group III nitride semiconductor substrate having a major surface defined by a nonpolar plane.

Abstract: Optical information recording and reproducing medium 10 has two recording layers of first and second recording layers 12 and 14, from a laser beam incident surface side. In each control area 21, recording layer management information containing at least information indicating recording states of a plurality of areas into which the inside of data recording area 22 of each recording layer is divided is recorded. When recording or reproducing is performed on the second recording layer 14, the recording layer management information is checked, and a laser beam output is changed based on a recording state of an area corresponding to the first recording layer 12.

Abstract: A positioning control device and method in which the relative position error in tracking is reduced by using the periodicity of position shift. The positioning control device comprises a position detecting unit for measuring the relative position error between the desired position of an objective member and a moving member, an adding unit for adding a position error signal output from the position detecting unit and a delay signal, a signal delay unit for outputting the delay signal which is obtained by delaying an output of the adding unit at a period corresponding to the position shift of the objective member, a drive unit for moving a moving member, and an inputting unit for inputting the signal of the sum of the position error signal and the delay signal to the drive unit and addition-inputting the delay signal to the drive unit through a filter having a predetermined frequency characteristic in a specific frequency range.

Abstract: A positioning control apparatus for controlling a moving member to trace the position of a target member which almost equally repeats the position shift at a predetermined period comprises a position detector for detecting a relative position error, a first adder for adding a delay signal and a position error signal, a signal delay unit for outputting the delay signal which is obtained by delaying an output signal of the first adder at a period corresponding to the position shift of the target member, a second adder for adding the position error signal and the delay signal, a third adder for adding an output of the second adder and the delay signal via a filter, a compensating unit for performing the compensation for offset and/or the compensation for stabilization of the positioning control apparatus based on an output of the third adder, a drive unit for driving the moving member based on an output of the compensating unit, and a delay-amount setting unit for setting the amount of delay of a signal delayed

Abstract: Optical information recording and reproducing medium 10 has two recording layers of first and second recording layers 12 and 14, from a laser beam incident surface side. In each control area 21, recording layer management information containing at least information indicating recording states of a plurality of areas into which the inside of data recording area 22 of each recording layer is divided is recorded. When recording or reproducing is performed on the second recording layer 14, the recording layer management information is checked, and a laser beam output is changed based on a recording state of an area corresponding to the first recording layer 12.

Abstract: A positioning control device and method in which the relative position error in tracking is reduced by using the periodicity of position shift. The positioning control device comprises a position detecting unit for measuring the relative position error between the desired position of an objective member and a moving member, an adding unit for adding a position error signal output from the position detecting unit and a delay signal, a signal delay unit for outputting the delay signal which is obtained by delaying an output of the adding unit at a period corresponding to the position shift of the objective member, a drive unit for moving a moving member, and an inputting unit for inputting the signal of the sum of the position error signal and the delay signal to the drive unit and addition-inputting the delay signal to the drive unit through a filter having a predetermined frequency characteristic in a specific frequency range.

Abstract: In case of pulling a focusing servo in a recording surface 2 of an optical disk 1, the focusing servo is pulled in a substrate surface 3 of the optical disk 1, thereafter, a focusing servo pull-in position is allowed to transfer to the recording surface 2 of the optical disk 1 by means of a focusing jump control circuit 12, whereby a focusing servo pull-in operation is made upon the recording surface 2, while an objective lens retreating control circuit 14 outputs a control signal in a direction along which the objective lens 4 is allowed to go away from the optical disk 1 for a predetermined time, and then, another control signal in a direction along which the objective lens 4 is allowed to be close to the optical disk 1 for a predetermined time in the case when an abnormal focusing servo pull-in operation was detected.

Abstract: A positioning control apparatus for controlling a moving member to trace the position of a target member which almost equally repeats the position shift at a predetermined period comprises a position detector for detecting a relative position error, a first adder for adding a delay signal and a position error signal, a signal delay unit for outputting the delay signal which is obtained by delaying an output signal of the first adder at a period corresponding to the position shift of the target member, a second adder for adding the position error signal and the delay signal, a third adder for adding an output of the second adder and the delay signal via a filter, a compensating unit for performing the compensation for offset and/or the compensation for stabilization of the positioning control apparatus based on an output of the third adder, a drive unit for driving the moving member based on an output of the compensating unit, and a delay-amount setting unit for setting the amount of delay of a signal delayed

Abstract: An aspect ratio converter converts a still image signal having an aspect ratio of 4:3 to a still image signal having a predetermined wide aspect ratio. A both-end pixel extractor extracts predetermined amounts of both left and right end images of a horizontal scanning period of the still image signal having an aspect ratio of 4:3. A both-wing image data preparing unit and a both-wing extrapolator use the extracted images to extrapolate a region of from both left and right ends of the horizontal scanning period of the still image signal having an aspect ratio of 4:3 to both left and right ends of the horizontal scanning period of the still image signal having the wide aspect ratio.

Abstract: In case of pulling a focusing servo in a recording surface 2 of an optical disk 1, the focusing servo is pulled in a substrate surface 3 of the optical disk 1, thereafter, a focusing servo pull-in position is allowed to transfer to the recording surface 2 of the optical disk 1 by means of a focusing jump control circuit 12, whereby a focusing servo pull-in operation is made upon the recording surface 2, while an objective lens retreating control circuit 14 outputs a control signal in a direction along which the objective lens 4 is allowed to go away from the optical disk 1 for a predetermined time, and then, another control signal in a direction along which the objective lens 4 is allowed to be close to the optical disk 1 for a predetermined time in the case when an abnormal focusing servo pull-in operation was detected.

Abstract: A still picture transmission system has a transmitter and a receiver. The transmitter includes a still picture generator for generating video data of a plurality of still pictures, an entry number generator for generating an entry number for each still picture, and a picture information generator for generating a picture information to each still picture. A list data is generated containing the entry numbers and corresponding picture informations. An encoder encodes the video data with the entry number inserted in a predetermined position correspondingly to each still picture. A multiplexer multiplexes and transmits the encoded video signal with the list data. The receiver separates the encoded video signal and list data. The list data is displayed. Looking at the list data, a particular entry number is selected. A still picture with the particular entry number is extracted from the encoded video signal and displayed.

Abstract: According to the present invention, a method for switching programs in a digital broadcasting is provided. In this method, on a transmission side, a physical channel number for transmitting a program having a program number therethrough is assigned to a part of the program number. On a receiving side, in changing program numbers from a first program number to a second program number, a second physical channel number, for transmitting a second program having the second program number therethrough, is identified based on the second program number; wherein it is determined whether or not the identified second physical channel number is the same as a first physical channel number which is now being received; and wherein if it is determined that the first and the second physical channel numbers are not the same, switching is performed for receiving the physical channel having the identified second physical channel number.

Abstract: A video signal format conversion apparatus, includes a memory for writing an input data by a first clock equal to a sampling rate of the input data and reading the input data by a second clock which is different from the first clock; a shift register for shifting the data read by the memory by the second clock; a multiplication and summation circuit for multiplying each of a plurality of data output from the shift register by a factor corresponding thereto among the plurality of factors and outputting a sum of values obtained by the multiplication by the second clock.