Abstract: A device for producing a shape model used for a matching process of an object to be worked in a robot system. The shape-model producing device includes a shape-data obtaining section for obtaining three-dimensional shape data of the object; a viewpoint setting section for setting, in a coordinate system to which the three-dimensional shape data obtained by the shape-data obtaining section belongs, a plurality of virtual viewpoints permitting the object placed in the coordinate system to be observed in directions different from each other; and a shape-model generating section for generating, as a plurality of shape models, a plurality of two-dimensional image data of the object, based on the three-dimensional shape data, the plurality of two-dimensional image data being estimated when the object is observed in the coordinate system from the plurality of virtual viewpoints set by the viewpoint setting section.

Abstract: A robot controller capable of automatically preparing a job program for a workpiece configured of a plurality of job elements is disclosed. A plurality of teaching programs for teaching the job for each job element making up the workpiece are stored in advance. Each teaching program has registered therein attribute information including the item number (identification information) and the sequence of application of the teaching program to each workpiece. The robot controller retrieves teaching programs having registered therein, as attribute information, the same item number as the input item number of the workpiece and prepares a main program such that the retrieved teaching programs are called sequentially as subprograms in accordance with the application sequence specified by the attribute information. Further, commands for moving to the job starting position and the job end position are added before and after the main program thereby to complete the main program.

Abstract: A programming device for making a program for returning a robot to its waiting position when the robot is stopped by an error. A robot control device is connected to the programming device via a network line. When the robot during operation is stopped by the error, information including data of a position where the robot is stopped is transferred to the programming device. The programming device makes the returning program, based on layout data, the received information and data including teaching positions and attribute data of the positions, by which the robot may be returned from the stop position to the waiting position without interfering with peripheral devices. The returning program is executed by using an offline simulation function of the programming device. The program is transferred to the robot control device after it is judged that interference will not occur. The robot may be safely returned to the waiting position by executing the returning program.

Abstract: A spot welding system including first and second spot welding robots, and a communication line connecting the first and second spot welding robots with each other so as to permit communication therebetween. The first spot welding robot includes a data transmitting section for transmitting welding data defining welding operations of the first and second spot welding robots through the communication line to the second spot welding robot, and a first control section for causing the first spot welding robot to perform a welding operation based on the welding data. The second spot welding robot includes a data receiving section for receiving the welding data transmitted from the data transmitting section of the first spot welding robot through the communication line, and a second control section for causing the second spot welding robot to perform a welding operation based on the welding data received by the data receiving section.

Abstract: An offline programming device in which a path for preventing interference may be automatically inserted such that a welding robot does not interfere with a jig clamping a workpiece to be welded. The models of the robot, the workpiece and the clamp jig are indicated on a display for determining the path for preventing interference. A simulation is carried out to judge that interference with the jig may occur. When it is judged that interference will occur, data of the preventing path suitable for a straight path passing through the jig are read out from a library including registered preventing paths corresponding to shapes of various jigs. The data of the preventing path includes the three-dimensional data of each point of the path as the incremental value in relation to a reference point of the path. Also, the orientation of a welding torch is registered.

Abstract: A gain-coupled DFB laser diode includes a multiple quantum well active layer and a pair of cladding layers sandwiching the multiple quantum well active layer vertically, wherein the multiple quantum well active layer includes a plurality of gain regions aligned in a direction of propagation of a laser beam and repeated periodically, each of the gain regions having a multiple quantum well structure, and a buried layer fills a gap between a pair of adjacent gain regions, wherein the buried layer includes a plurality of high-refractive index layers and a plurality of low-refractive index layers, each of the high-refractive index layers is formed of a first semiconductor material having a first bandgap, while each of the low-refractive index layers is formed of a second semiconductor material having a second, larger bandgap.

Abstract: A method of manufacturing a distributed feedback semiconductor laser, has the steps of: growing on a semiconductor substrate a lamination of alternately stacked lower barrier layer and lower well layer having a band gap narrower than the lower barrier layer, to form a lower quantum well structure; growing an intermediate layer on an uppermost lower well layer, the intermediate layer having a band gap broader than the lower well and a thickness thicker than the lower barrier layer; growing on the intermediate layer a lamination of alternately stacked upper well layer and upper barrier layer having a band gap broader than the upper well layer and a thickness thinner than the intermediate layer, to form an upper quantum well structure; forming a mask on the upper quantum well structure, the mask having periodical pattern; by using the mask as an etching mask, etching the upper quantum well structure in a periodical shape by using the intermediate layer as an etching margin layer; and removing the mask.

Abstract: A lower quantum well structure is formed extending along a resonator direction, the lower quantum well structure being formed by alternately stacking lower barrier layers and lower well layers having a band gap narrower than a band gap of the lower barrier layers. An intermediate layer is disposed over the lower quantum well structure. The intermediate layer has a band gap broader than the band gap of the lower barrier layers. An upper quantum well structure is periodically disposed over the intermediate layer along the resonator direction. The upper quantum well structure is formed by alternately stacking upper well layers and upper barrier layers having a band gap broader than a band gap of the upper well layers. A distributed feedback semiconductor laser is provided which is not likely to oscillate in the mode at a shorter wavelength and is likely to oscillate in the mode at a longer wavelength.

Abstract: A gain-coupled DFB laser diode includes a multiple quantum well active layer and a pair of cladding layers sandwiching the multiple quantum well active layer vertically, wherein the multiple quantum well active layer includes a plurality of gain regions aligned in a direction of propagation of a laser beam and repeated periodically, each of the gain regions having a multiple quantum well structure, and a buried layer fills a gap between a pair of adjacent gain regions, wherein the buried layer includes a plurality of high-refractive index layers and a plurality of low-refractive index layers, each of the high-refractive index layers is formed of a first semiconductor material having a first bandgap, while each of the low-refractive index layers is formed of a second semiconductor material having a second, larger bandgap.

Abstract: A DFB laser in which a thickness of an active layer changes periodically and a greater part of current injected from external sides is selectively injected into the thick regions (projected regions) of the active layer. Therefore, the ratio of the gain coupling to the refractive index coupling can be further increased, and a threshold current can be lowered, and stability of single mode oscillation can also be improved.

Abstract: There is provided a semiconductor laser which comprises a first cladding layer formed of compound semiconductor having first conductivity type impurity and having a mesa-shaped projection, an active layer formed on the projection like a stripe and having side surfaces which are inclined at an angle of more than 70 degrees but less than 90 degrees relative to an upper surface of the first cladding layer, buried layers formed on both sides of the projection and having second conductivity type impurity, current blocking layers each having one end which contacts a virtual surface obtained by extending upward a side surface of the active layer and having a first facet which extends downward from the one end and is inclined by about 55 degrees relative to the upper surface of the first cladding layer and formed on each buried layer and having the first conductivity type impurity, and second cladding layers formed on the current blocking layers and the active layer and having the second conductivity type impurity.

Abstract: There is provided a semiconductor laser which comprises a first cladding layer formed of compound semiconductor having first conductivity type impurity and having a mesa-shaped projection, an active layer formed on the projection like a stripe and having side surfaces which are inclined at an angle of more than 70 degrees but less than 90 degrees relative to an upper surface of the first cladding layer, buried layers formed on both sides of the projection and having second conductivity type impurity, current blocking layers each having one end which contacts a virtual surface obtained by extending upward a side surface of the active layer and having a first facet which extends downward from the one end and is inclined by about 55 degrees relative to the upper surface of the first cladding layer and formed on each buried layer and having the first conductivity type impurity, and second cladding layers formed on the current blocking layers and the active layer and having the second conductivity type impurity.

Abstract: In a semiconductor light-emitting device including an MQW diffraction grating structure mainly used in a gain-coupled DFB laser, the ratio of the gain coupling coefficient to the index coupling coefficient is increased by making each well layer in MQW-A thicker than that in MQW-B. Each well layer and each barrier layer in the MQW structure are made of different compositions of GaInAsP. This implements a semiconductor light-emitting device with high wavelength stability, which does not induce any mode hop even during modulation with high output power or even when external optical feedback is present.

Abstract: A DFB laser in which a thickness of an active layer changes periodically and a greater part of current injected from external sides is selectively injected into the thick regions (projected regions) of the active layer. Therefore, the ratio of the gain coupling to the refractive index coupling can be further increased, and a threshold current can be lowered, and stability of single mode oscillation can also be improved.

Abstract: A method of manufacturing a distributed feedback semiconductor laser, has the steps of: growing on a semiconductor substrate a lamination of alternately stacked lower barrier layer and lower well layer having a band gap narrower than the lower barrier layer, to form a lower quantum well structure; growing an intermediate layer on an uppermost lower well layer, the intermediate layer having a band gap broader than the lower well and a thickness thicker than the lower barrier layer; growing on the intermediate layer a lamination of alternately stacked upper well layer and upper barrier layer having a band gap broader than the upper well layer and a thickness thinner than the intermediate layer, to form an upper quantum well structure; forming a mask on the upper quantum well structure, the mask having periodical pattern; by using the mask as an etching mask, etching the upper quantum well structure in a periodical shape by using the intermediate layer as an etching margin layer; and removing the mask.

Abstract: In a semiconductor light-emitting device including an MQW diffraction grating structure mainly used in a gain-coupled DFB laser, the ratio of the gain coupling coefficient to the index coupling coefficient is increased by making each well layer in MQW-A thicker than that in MQW-B. Each well layer and each barrier layer in the MQW structure are made of different compositions of GaInAsP. This implements a semiconductor light-emitting device with high wavelength stability, which does not induce any mode hop even during modulation with high output power or even when external optical feedback is present.

Abstract: An optical semiconductor device of the present invention is provided with a core layer having a quantum well layer in that film thickness gets thinner from a inner region to an end portion in an optical waveguide region.

Abstract: The present invention relates to a robot path planning method for determining the path of a robot, taking into consideration the bending effect of the robot path when heavy tools are load onto the robot. Specifically, straight line P'-Q' to be actually drawn by the distal end of the robot tool is calculated by using the positions P and Q of the distal end of the tool at the start point and at the end point of the straight line recognized by the robot controller. And, the interpolation points H1', H2', H3', . . . are set on this line P'-Q'. Then, the bending amount .DELTA..theta.pj and .DELTA..theta.qj at the start point P' and at the end point Q' of this line P'-Q' are respectively determined. And, the bending amount at each interpolation point H1', H2', . . . are calculated from these bending amounts .DELTA..theta.pj and .DELTA..theta.qj, and the position on the line P'-Q' of each interpolation point. Then, the values obtained by subtracting from each interpolation point H1', H2', . . .

Abstract: A fabricating method of compound semiconductor device is proposed which has a step of varying selective growth ratio of crystal by changing either a mean free path of material gas in gas atmosphere for use in crystal growth or a thickness of a stagnant layer of the material gas, using selective growth mask having opening portion consisting of first region having a narrow width and second region having a wide width.

Abstract: An optical semiconductor device of the present invention is provided with a core layer having a quantum well layer in that film thickness gets thinner from a inner region to an end portion in an optical waveguide region.