Abstract: Provided is a semiconductor optical device, which has a buried heterostructure structure and is formed in a structure capable of reducing a parasitic capacitance to further improve characteristics thereof, and also provided are an optical transmitter module, an optical transceiver module, and an optical transmission equipment. The semiconductor optical device includes a modulator portion for modulating light input along an emitting direction and radiating the modulated light, the modulator portion including: a mesa-stripe structure, which includes an active layer and extends in the emitting direction; and a buried layer provided adjacent to each side of the mesa-stripe structure, in which a distance between a lower surface of the buried layer and a lower surface of the active layer is 20% or more of a distance between the lower surface and an upper surface of the buried layer.

Abstract: A display apparatus includes a plurality of pixels disposed in a matrix pattern, each of the pixels emitting light, an acquisition unit for acquiring degradation characteristics of an emission luminance of each pixel from a video signal or a signal output from the pixel, and a detection unit for detecting a boundary of pixels showing different degradation characteristics of the plurality of pixels based on the degradation characteristics acquired by the acquisition unit. A calculation unit calculates a correction amount of the video signal to the pixels in a periphery of the boundary such that the emission luminance is gently varied in the periphery of the boundary when the plurality of pixels in the periphery of the boundary detected by the detection unit are caused to emit light with a same video signal. In addition, a correction unit corrects the video signal based on the calculated correction amount, and a video image is displayed by the plurality of pixels based on the corrected video signal.

Abstract: An active-matrix display includes a data line, at least one select line, a control unit supplying a voltage signal and a current signal to the data line, and a pixel circuit receiving the voltage signal and the current signal from the data line to drive a light emitting element, the control unit including a voltage or first current source supplying a voltage or current pulse to the data line in order to make the voltage holding unit hold the voltage signal for making the light emitting element emit light having predetermined brightness in a first selection period in which the first switch is closed, a second current source supplying the current signal for making the light emitting element emit light having the predetermined brightness to the data line in a second selection period in which the first switch and the second switch are closed, a detection circuit detecting potential held in the voltage holding unit in the second selection period, and a correction unit correcting the voltage signal based on a relat

Abstract: A dimming method of an organic EL displaying apparatus having a displaying unit constructed by combining pixels each having a substrate, an organic EL element formed over the substrate, a power supply line for supplying a power source to the organic EL element, and at least one TFT provided on a wiring path from the power supply line to the organic EL element. The TFT has a semiconductor layer which is arranged between a source electrode and a drain electrode and is electrically connected to the source electrode and the drain electrode. A laser beam is irradiated from a downward direction of the substrate to a region which does not overlap a gate electrode, the source electrode, the drain electrode, and the wiring layer when seen as a plan view in a plane region where the semiconductor layer is provided.

Abstract: A display apparatus includes a scanning line, a signal line, and a pixel circuit. The pixel circuit is selected according to a signal applied to the scanning line, and a signal is input to the selected pixel circuit from the signal line. The pixel circuit include a holding capacitor, a first switch which opens and closes connection between one terminal of the light emitting element and the signal line in accordance with a signal applied to the scanning line, and a second switch which opens and closes connection between one terminal of the holding capacitor and the signal line in accordance with a signal applied to the scanning line.

Abstract: Provided is a semiconductor optical device, which has a buried heterostructure structure and is formed in a structure capable of reducing a parasitic capacitance to further improve characteristics thereof, and also provided are an optical transmitter module, an optical transceiver module, and an optical transmission equipment. The semiconductor optical device includes a modulator portion for modulating light input along an emitting direction and radiating the modulated light, the modulator portion including: a mesa-stripe structure, which includes an active layer and extends in the emitting direction; and a buried layer provided adjacent to each side of the mesa-stripe structure, in which a distance between a lower surface of the buried layer and a lower surface of the active layer is 20% or more of a distance between the lower surface and an upper surface of the buried layer.

Abstract: Conventional I-form crystals of 5-hydroxy-1-methylhydantoin contain, remaining therein in a considerable amount, the organic solvent used in a purification step. In contrast, in II-form crystals, the amount of the organic solvent remaining therein is smaller than the detection limit. Namely, the II-form crystals contain substantially no residual organic solvent. The novel II-form crystals of 5-hydroxy-1-methylhydantoin obtained through recrystallization from water not only contain substantially no residual organic solvent, but also have a high bulk density and are hence advantageous for pharmaceutical preparation. They further have properties advantageous for production, such as low adhesion. The crystals are significantly useful as a material for medicines required to have high safety, such as drugs for renal insufficiency.

Abstract: A method of manufacturing semiconductor laser device capable of reducing ?L, with manufacturing restrictions satisfied, is provided. In a distributed-feedback or distributed-reflective semiconductor laser device, immediately before burying regrowth of a diffraction grating, halogen-based gas is introduced to a reactor, and etching is performed on the diffraction grating so that each side wall has at least two or more crystal faces and a ratio of length of an upper side in a waveguide direction to a bottom side parallel to a (100) surface is 0 to 0.3. And, a reactive product formed on side surfaces of the diffraction grating and in trench portions between stripes of the diffraction grating at an increase of temperature for regrowth is removed. Therefore, the diffraction grating with reduced height and a sine wave shape is obtained, thereby ?L of the device is reduced. Thus, an oscillation threshold and optical output efficiency can be improved.

Abstract: A method of reproducing multilevel information using a light spot. The multilevel information is recorded by defining virtual cells at regular intervals on tracks of an optical information recording medium and varying sizes of information pits in the cells. The method includes the steps of obtaining cell boundary values, each of the cell boundary values being obtained by performing sampling when the center of the light spot reaches a boundary between adjacent cells, calculating cell boundary value metrics on the basis of the cell boundary values and prestored reference values for the cell boundary values, calculating path metrics on the basis of the cell boundary value metrics, selecting a path metric having a minimum value of the path metrics, and reproducing the multilevel information on the basis of the path metric having the minimum value of the path metrics.

Abstract: An optical information reproducing method of reproducing multivalued information recorded on a track of an optical information medium having a recording/reproducing region, which has virtual cells arranged thereon at regular spacings, the multivalued information being recorded thereon by changing a length of an information pit in a track direction or an area of the information pit in a cell with the use of a light spot, and the multivalued information being reproduced by detecting the level of a multistage reproduced signal from the information pit.

Abstract: An optical information reproducing method of reproducing multivalued information recorded on a track of an optical information medium having a recording/reproducing region, which has virtual cells arranged thereon at regular spacings, the multivalued information being recorded thereon by changing a length of an information pit in a track direction or an area of the information pit in a cell with the use of a light spot, and the multivalued information being reproduced by detecting the level of a multistage reproduced signal from the information pit.

Abstract: In three consecutive cells consisting of a preceding cell, a center cell, and a subsequent cell, a possible change rate of the amplitude of a reproduced signal for the center cell with respect to the sum of the multiple values of the preceding and subsequent cells is obtained in advance. Then, for reproduction, the sum of the multiple values of the adjacent preceding and subsequent cells is obtained with respect to each cell. The amplitude of the reproduced signal obtained at the center cell is corrected to be closer to a reference value on the basis of the obtained change rate and sum.

Abstract: An optical information recording/reproducing apparatus is adapted to record and/or reproduce multilevel information on/or from an optical information recording medium. The multilevel information is recorded in the form of pits in cells virtually formed at regular intervals on a track. The respective levels are represented by varying the length or the area of information pits such that a reproduced signal has a different amplitude level depending on the length or the area of information pits. A reproduced signal correction circuit corrects a reproduced signal obtained by performing sampling at the center of each cell. An error power calculation circuit calculates error power on the basis of the difference between the corrected reproduced signal and an ideal value of each level of the cell. A decoder performs decoding on the basis of the calculated error power values.

Abstract: An optical information reproducing method of reproducing multivalued information recorded on a track of an optical information medium having a recording/reproducing region, which has virtual cells arranged thereon at regular spacings, the multivalued information being recorded thereon by changing a length of an information pit in a track direction or an area of the information pit in a cell with the use of a light spot, and the multivalued information being reproduced by detecting the level of a multistage reproduced signal from the information pit.

Abstract: An optical information reproducing method of reproducing multivalued information recorded on a track of an optical information medium having a recording/reproducing region, which has virtual cells arranged thereon at regular spacings, the multivalued information being recorded thereon by changing a length of an information pit in a track direction or an area of the information pit in a cell with the use of a light spot, and the multivalued information being reproduced by detecting the level of a multistage reproduced signal from the information pit.

Abstract: An optical information reproducing method of reproducing multivalued information recorded on a track of an optical information medium having a recording/reproducing region, which has virtual cells arranged thereon at regular spacings. The multivalued information is recorded thereon by changing a length of an information pit in a track direction or an area of the information pit in a cell with the use of a light spot. The multivalued information is reproduced by detecting the level of a multistage reproduced signal from the information pit. The method includes sampling a reproduced signal in the multivalued information recorded in one cell with an M-value (M<N), which is arranged at each of the plurality of cells recorded with an N-value (N?3) on the track, and detecting a cell center value.

Abstract: An optical information reproducing method capable of determining multi-level information with high precision, and an apparatus for the method. Specifically, a cell having a reduced multi-level is provided in a portion of a data region to perform the level correction or automatic gain control. For example, a cell recorded with an M-value for each group including a plurality of cells, each of which is recorded with an N-value (N>3, M<N), is provided. A reproduction signal level of a cell recorded with the N-value, which follows the cell recorded with the M-value, is corrected based on a difference between a cell center value of a reproduction signal sampled when a center of a light spot is moved to a center of the cell recorded with the M-value and a reference value obtained from learning information.

Abstract: In an optical semiconductor device that emits or receives light substantially perpendicularly to or in parallel to an active surface formed on a semiconductor substrate, the optical semiconductor device, an electrode that is formed on the active surface side and connected to the active surface is stepped or tapered at an end of the electrode. The electrode of the optical semiconductor device is formed of three layers including an adhesive layer, a diffusion prevention layer, and an Au layer, and the stepped configuration or the taped configuration is formed by a difference of the thickness of the Au layer or the thickness of the adhesive layer/diffusion prevention layer/Au layer.

Abstract: In a mesa type PIN-PD formed using a heavily doped semiconductor material, a high frequency response is degraded as slow carriers occur in a heavily doped layer when light incident into a light receiving section transmits through an absorbing layer and reaches the heavily doped layer on a side near the substrate. In a p-i-n multilayer structure, a portion corresponding to a light receiving section of a heavily doped layer on a side near a substrate is previously made thinner than the periphery of the light receiving section by an etching or selective growth technique, over which an absorbing layer and another heavily doped layer are grown to form the light receiving section of mesa structure. This makes it possible to form a good ohmic contact and to realize a PIN-PD with excellent high frequency response characteristics.

Abstract: An active-matrix display includes a data line, at least one select line, a control unit supplying a voltage signal and a current signal to the data line, and a pixel circuit receiving the voltage signal and the current signal from the data line to drive a light emitting element, the control unit including a voltage or first current source supplying a voltage or current pulse to the data line in order to make the voltage holding unit hold the voltage signal for making the light emitting element emit light having predetermined brightness in a first selection period in which the first switch is closed, a second current source supplying the current signal for making the light emitting element emit light having the predetermined brightness to the data line in a second selection period in which the first switch and the second switch are closed, a detection circuit detecting potential held in the voltage holding unit in the second selection period, and a correction unit correcting the voltage signal based on a relat