Abstract: A rod acceleration reducing mechanism is provided in a bottom-side oil chamber in an inner tube. The rod acceleration reducing mechanism includes a housing having a cylindrical accommodating casing screwed onto a fastening bolt of a bottom valve and a cap, a free piston displaceably fitted in the housing to define variable chambers at vertically opposite sides thereof, and elastic disks applying an elastic resistance to the displacement of the free piston. The variable chambers formed in the housing are variable in volume in response to pressure changes in the bottom-side oil chamber and the reservoir chamber. Thus, rod vibration can be generated by the rod acceleration reducing mechanism to reduce generation of rapping noise during running of the vehicle.

Abstract: An object of the present invention is to provide a damping force adjustable hydraulic shock absorber, in which response delay of a pressure control valve and self-excited vibration of a valve body can be prevented. A damping force is generated by controlling an oil flow between an annular oil passage 21 and a reservoir 4 generated by a sliding movement of a piston in a cylinder with use of a back-pressure type main valve 27 and a pressure control valve 28. The damping force is directly generated by the pressure control valve 28, and a valve-opening pressure of the main valve 27 is adjusted by adjusting an inner pressure of a back-pressure chamber 53. In the pressure control valve 28, a valve spring 57 is disposed between a valve body 56 and a plunger 34. A mass of the valve body 56 is sufficiently less than that of a plunger 34, and a spring stiffness of the valve spring 57 is higher than that of a plunger spring 36.

Abstract: The present invention provides a new arrangement of the stem and the cap resistance-welded to the stem, in which the deformation induced by the welding in a portion adjacent to the projection does not cause the failure for the assembly of the module. The cap and the stem of the present module provided first and second portions. The diameter of the second portion is greater than that of the first portion such that, even the welding deforms the first portions of the cap and the stem; the deformed portion is inside of respective second portions.

Abstract: The present invention provides a receiving optical subassembly (ROSA) with a co-axial shape and a stem for mounting semiconductor devices thereon that improves the high frequency performance of the ROSA. The ROSA mounts a photodiode (PD) and a pre-amplifier on a stem and the stem has a hollow the PD and the pre-amplifier are mounted therein. Since the hollow has a depth substantially equal to a thickness of the pre-amplifier, the bonding wire from the pre-amplifier to the surface of the stem may become shortest to reduce the parasitic inductance of the bonding wire and to enhance the high frequency performance of the ROSA.

Abstract: The present invention provides a new arrangement of the stem and the cap resistance-welded to the stem, in which the deformation induced by the welding in a portion adjacent to the projection does not cause the failure for the assembly of the module. The cap and the stem of the present module provided first and second portions. The diameter of the second portion is greater than that of the first portion such that, even the welding deforms the first portions of the cap and the stem; the deformed portion is inside of respective second portions.

Abstract: The object of the present invention is to provide an optical module for the WDM communication system, in which the oscillation wavelength is on the grid of the WDM regulation, moreover the optical output power and the oscillation wavelength can be controlled independently. The present module comprises a semiconductor light-emitting device, a wedge shaped etalon device and two light-receiving devices. The etalon device contains a first portion, on which the anti-reflection films are coated, and a second portion. One of the receiving devices detects light transmitted through the first portion of the etalon device, while the other device detects light through the second portion. Signal from the former device controls the output power of the light-emitting device, while the signal from the latter receiving device controls the oscillation wavelength of the laser.

Abstract: An optical assembly of the present invention comprises a package installing a semiconductor optical device therein, a metal sleeve attached to the package, and the resin holder disposed between package and the sleeve member. When this optical assembly is installed within the optical transceiver and even the metal sleeve extrudes into the optical receptacle and is exposed to the outside there, the EMI noise can be prevented from importing into the transceiver and radiating to the outside, because the resin holder made of substantially insulating material is disposed between the sleeve and the package.

Abstract: The present invention provides a receiving optical subassembly (ROSA) with a co-axial shape and a stem for mounting semiconductor devices thereon that improves the high frequency performance of the ROSA. The ROSA mounts a photodiode (PD) and a pre-amplifier on a stem and the stem has a hollow the PD and the pre-amplifier are mounted therein. Since the hollow has a depth substantially equal to a thickness of the pre-amplifier, the bonding wire from the pre-amplifier to the surface of the stem may become shortest to reduce the parasitic inductance of the bonding wire and to enhance the high frequency performance of the ROSA.

Abstract: An optical assembly of the present invention comprises a package installing a semiconductor optical device therein, a metal sleeve attached to the package, and the resin holder disposed between package and the sleeve member. When this optical assembly is installed within the optical transceiver and even the metal sleeve extrudes into the optical receptacle and is exposed to the outside there, the EMI noise can be prevented from importing into the transceiver and radiating to the outside, because the resin holder made of substantially insulating material is disposed between the sleeve and the package.

Abstract: The light-emitting module includes a semiconductor light-emitting device, a first optical detector for monitoring the magnitude of light emitted from the semiconductor device, a second optical detector for monitoring an oscillation wavelength of the semiconductor device, and an Etalon. The first detector is located in a position where the wavelength variation of the transmitted light from the Etalon is relatively small, while the second detector is located in a position where the wavelength variation of the transmitted light is relatively large. The geometrical size of the second detector along the first direction is wider than that along the second direction normal to the first direction; this thus enhances the efficiency of wavelength sensitivity.

Abstract: The object of the present invention is to provide an optical module for the WDM communication system, in which the oscillation wavelength is on the grid of the WDM regulation, moreover the optical output power and the oscillation wavelength can be controlled independently. The present module comprises a semiconductor light-emitting device, a wedge shaped etalon device and two light-receiving devices. The etalon device contains a first portion, on which the anti-reflection films are coated, and a second portion. One of the receiving devices detects light transmitted through the first portion of the etalon device, while the other device detects light through the second portion. Signal from the former device controls the output power of the light-emitting device, while the signal from the latter receiving device controls the oscillation wavelength of the laser.

Abstract: The object of the present invention is to provide an optical module for a WDM communication system, in which the oscillation wavelength is on the grid of the WDM regulation. The optical output power and the oscillation wavelength can be controlled independently. The present module includes a semiconductor light-emitting device, a wedge shaped etalon device and two light-receiving devices. The etalon contains a second portion, on which anti-reflection films are coated, and a first portion. One of the receiving devices detects light transmitted through the second portion of the etalon, while the other device detects light through the first portion. A signal from the former device controls the output power of the light-emitting device, while a signal from the latter receiving device controls the oscillation wavelength of the laser.

Abstract: A system display apparatus detects a display scale by which a distribution line system diagram fits in a display range from the relationship between coordinates of four points of a rectangle in which a distribution line system to be displayed falls and the display range of the screen, and displays the distribution line system to be displayed with an adequate size on a display section.

Abstract: A main portion 10 of an optical module 1 includes a thermoelectric cooler 21, and a chip carrier 22b placed on the cooler 21. A semiconductor light-emitting device 31, a lens 32, photodetectors 33a, 33b, and an etalon 34 are directly or indirectly mounted on the chip carrier 22b. Supporting members 36a and 36b are also fixed on the chip carrier 22b. A roof 35 is supported by the supporting members 36a, 36b and positioned above the etalon 34. The roof 35, supporting members 36a, 36b and chip carrier 22b are maintained at substantially equal temperatures by the cooler 21. As a result, the temperature of the etalon 34 is stabilized, and therefore the variation in the lock wavelength is suppressed.

Abstract: A main portion 10 of an optical module 1 includes a thermoelectric cooler 21, and a chip carrier 22b placed on the cooler 21. A semiconductor light-emitting device 31, a lens 32, photodetectors 33a, 33b, and an etalon 34 are directly or indirectly mounted on the chip carrier 22b. Supporting members 36a and 36b are also fixed on the chip carrier 22b. A roof 35 is supported by the supporting members 36a, 36b and positioned above the etalon 34. The roof 35, supporting members 36a, 36b and chip carrier 22b are maintained at substantially equal temperatures by the cooler 21. As a result, the temperature of the etalon 34 is stabilized, and therefore the variation in the lock wavelength is suppressed.

Abstract: Present invention relates to a light-emitting module used in the WDM optical source. The module comprises a semiconductor light-emitting device, an Ethalon, a plurality of optical detectors, and a switching element for selecting one of detectors. The detectors monitor light transmitted through individual potions where the transmittance of the Ethalon has a peculiar periodic behavior with almost same period, and generate outputs reflecting the periodic behavior. By selecting one of outputs from detectors by switching element and by feeding it back to temperature of the light-emitting device, the oscillation wavelength locks to the value of the WDM standard. In the present module, it is not necessary to use a thicker Ethalon to obtain the wavelength interval of the WDM standard.

Abstract: The light-emitting module 1a comprises a semiconductor light-emitting device 16, a first optical detector 20a for monitoring magnitude of light emitted from the semiconductor device, a second optical detector 20b for monitoring a oscillation wavelength of the semiconductor device, and an Ethalon. The first detector 20a locates in the position where the wavelength variation of the transmitted light from the Ethalon is relatively small, while the second detector locates in the position where the wavelength variation of the transmitted light is relatively large. The geometrical size of the second detector along the first direction is wider than that along the second direction normal to the first direction, thus enhances the efficiency of the sensitivity for the wavelength.

Abstract: The object of the present invention is to provide an optical module for the WDM communication system, in which the oscillation wavelength is on the grid of the WDM regulation, moreover the optical output power and the oscillation wavelength can be controlled independently. The present module comprises a semiconductor light-emitting device, a wedge shaped Ethalon device and two light-receiving devices. The Ethalon contains a first portion, on which the anti-reflection films are coated, and a second portion. One of the receiving devices detects light transmitted through the first portion of the Ethalon, while the other device detects light through the second portion. Signal from the former device controls the output power of the light-emitting device, while the signal from the latter receiving device controls the oscillation wavelength of the laser.