Abstract: An optical transceiver includes an attenuation mechanism capable of attenuating the electromagnetic waves in an intermediate space of the interior space. The interior space is continuous in a first direction between the photoelectric device and the optical connector, the interior space being surrounded with a conductive surface from every direction perpendicular to the first direction. The attenuation mechanism is a post structure including some conductive posts electrically continuous to the conductive surface, the conductive posts extending in a second direction perpendicular to the first direction, the conductive posts being arranged at some points in a plan view along the second direction, the points being at vertices of some quadrangles, adjacent quadrangles of which share one side with each other, the quadrangles being arranged in the first direction, the optical fiber passing through at least one adjacent pair of the quadrangles in the first direction.

Abstract: An optical module includes at least one optical sub-assembly; at least one control circuit configured to control the at least one optical sub-assembly; and a housing including a first case and a second case, wherein the optical module is configured to be plugged in and unplugged from an optical transmission equipment including a heat sink provided at a joining portion with the first case, wherein, through fitting of the first case and the second case, the housing accommodates the at least one optical sub-assembly and the at least one control circuit inside the housing, and wherein a material of the first case has a thermal conductivity higher than a material of the second case.

Abstract: A gas engine drive system includes: a gas engine including combustion chamber; a turbocharger including a compressor and turbine; a fuel injection system that injects fuel gas into intake air that is supplied from compressor to combustion chamber via an intake passage; a pressure detector detecting a charge air pressure; a temperature detector detecting the intake air's temperature; and controller controlling the fuel injection system. The controller: when required output decreases, determines the charge air pressure's lean limit based on target injection amount corresponding to required output that has decreased; if the charge air pressure is lower than or equal to the lean limit, decreases fuel injection amount to target injection amount; if the charge air pressure is higher than lean limit, brings fuel injection amount to zero. When the charge air pressure becomes lower than or equal to the lean limit, increases fuel injection amount to target injection amount.

Abstract: An optical module includes at least one optical sub-assembly; at least one control circuit configured to control the at least one optical sub-assembly; and a housing including a first case and a second case, wherein the optical module is configured to be plugged in and unplugged from an optical transmission equipment including a heat sink provided at a joining portion with the first case, wherein, through fitting of the first case and the second case, the housing accommodates the at least one optical sub-assembly and the at least one control circuit inside the housing, and wherein a material of the first case has a thermal conductivity higher than a material of the second case.

Abstract: A gas engine system controller: calculates a delay calculation value of a knocking occurrence ratio; determines a primary target ignition timing; sets the primary target ignition timing as a current ignition timing if the occurrence ratio difference is positive and an ignition timing does not exceed a converted value of a first advance rate; determines whether a rapid advance condition is satisfied if the occurrence ratio difference is positive and the ignition timing difference exceeds the converted value of the first advance rate; sets a secondary target ignition timing as the current ignition timing if the rapid advance condition is not satisfied, the secondary target ignition timing obtained by adding the converted value of the first advance rate to the previous ignition timing; and determines the current ignition timing so as to achieve a second advance rate greater than the first advance rate if the rapid advance condition is satisfied.

Abstract: A method of controlling a gas engine that is operated under lean-burn conditions, the method adjusting ignition timing such that a delay calculation value of an actual knocking occurrence ratio becomes a target occurrence ratio, the method comprising: when a delay calculation value of a maximum pressure in a cylinder of the gas engine is greater than or equal to a reference value, converting the delay calculation value into a virtual knocking occurrence ratio greater than or equal to a value greater than the target occurrence ratio; and either adding the virtual knocking occurrence ratio to the delay calculation value of the actual knocking occurrence ratio and then comparing the resulting delay calculation value of the actual knocking occurrence ratio with the target occurrence ratio, or comparing the virtual knocking occurrence ratio instead of the delay calculation value of the actual knocking occurrence ratio with the target occurrence ratio.

Abstract: A gas engine drive system includes: a gas engine; a turbocharger including a compressor and a turbine connected to the gas engine; a fuel injection valve provided on the gas engine; a fuel supply line leading a fuel gas to the fuel injection valve, the fuel supply line having a pressure regulating valve; a first pressure meter detecting an intake air pressure; a second pressure meter detecting a fuel supply pressure being a pressure at a pressure regulating valve downstream side; and a controller controlling the pressure regulating valve such that a pressure difference between the fuel supply pressure and the intake air pressure is a target value. The controller changes the target value from a first to a second setting value higher than the first when a load on the gas engine increases rapidly or when a calorific value of the fuel gas is less than a threshold.

Abstract: A method of controlling a gas engine connected to a turbocharger including a compressor and a turbine includes: performing a knocking control operation of optimizing an ignition timing as a steady operation; and in a case where a load of the gas engine increases during the steady operation, when a degree of increase in the load is relatively small, gradually increasing an actual fuel injection amount while keeping the ignition timing, and when the degree of increase in the load is relatively great, retarding the ignition timing and then gradually increasing the actual fuel injection amount.

Abstract: A gas engine drive system includes: a gas engine including combustion chamber; a turbocharger including a compressor and turbine; a fuel injection system that injects fuel gas into intake air that is supplied from compressor to combustion chamber via an intake passage; a pressure detector detecting a charge air pressure; a temperature detector detecting the intake air's temperature; and controller controlling the fuel injection system. The controller: when required output decreases, determines the charge air pressure's lean limit based on target injection amount corresponding to required output that has decreased; if the charge air pressure is lower than or equal to the lean limit, decreases fuel injection amount to target injection amount; if the charge air pressure is higher than lean limit, brings fuel injection amount to zero. When the charge air pressure becomes lower than or equal to the lean limit, increases fuel injection amount to target injection amount.

Abstract: A method of controlling a gas engine connected to a turbocharger including a compressor and a turbine includes: performing a knocking control operation of optimizing an ignition timing as a steady operation; and in a case where a load of the gas engine increases during the steady operation, when a degree of increase in the load is relatively small, gradually increasing an actual fuel injection amount while keeping the ignition timing, and when the degree of increase in the load is relatively great, retarding the ignition timing and then gradually increasing the actual fuel injection amount.

Abstract: A gas engine system controller: calculates a delay calculation value of a knocking occurrence ratio; determines a primary target ignition timing; sets the primary target ignition timing as a current ignition timing if the occurrence ratio difference is positive and an ignition timing does not exceed a converted value of a first advance rate; determines whether a rapid advance condition is satisfied if the occurrence ratio difference is positive and the ignition timing difference exceeds the converted value of the first advance rate; sets a secondary target ignition timing as the current ignition timing if the rapid advance condition is not satisfied, the secondary target ignition timing obtained by adding the converted value of the first advance rate to the previous ignition timing; and determines the current ignition timing so as to achieve a second advance rate greater than the first advance rate if the rapid advance condition is satisfied.

Abstract: A gas engine drive system includes: a gas engine; a turbocharger including a compressor and a turbine connected to the gas engine; a fuel injection valve provided on the gas engine; a fuel supply line leading a fuel gas to the fuel injection valve, the fuel supply line having a pressure regulating valve; a first pressure meter detecting an intake air pressure; a second pressure meter detecting a fuel supply pressure being a pressure at a pressure regulating valve downstream side; and a controller controlling the pressure regulating valve such that a pressure difference between the fuel supply pressure and the intake air pressure is a target value. The controller changes the target value from a first to a second setting value higher than the first when a load on the gas engine increases rapidly or when a calorific value of the fuel gas is less than a threshold.

Abstract: A method of controlling a gas engine that is operated under lean-burn conditions, the method adjusting ignition timing such that a delay calculation value of an actual knocking occurrence ratio becomes a target occurrence ratio, the method comprising: when a delay calculation value of a maximum pressure in a cylinder of the gas engine is greater than or equal to a reference value, converting the delay calculation value into a virtual knocking occurrence ratio greater than or equal to a value greater than the target occurrence ratio; and either adding the virtual knocking occurrence ratio to the delay calculation value of the actual knocking occurrence ratio and then comparing the resulting delay calculation value of the actual knocking occurrence ratio with the target occurrence ratio, or comparing the virtual knocking occurrence ratio instead of the delay calculation value of the actual knocking occurrence ratio with the target occurrence ratio.

Abstract: Provided are a printed circuit board configured to achieve reduction in impedance of a differential transmission line extending in a stacking direction, and an optical module. The printed circuit board includes a stacking-direction differential transmission line extending in the stacking direction, including: a differential signal via pair including a first signal via and a second signal via; and a plurality of conductor plate pairs each including a first conductor plate expanding outward from the first signal via, and a second conductor plate expanding outward from the second signal via. With respect to a perpendicular bisector of a center-of-gravity line segment connecting centers of gravity of the first and second signal vias, in each of the plurality of conductor plate pairs, centers of gravity of contours of the first and second conductor plates are located on inner sides of the centers of gravity.

Abstract: The optical module includes a housing having a first opening for inputting or outputting a first electric signal, a second opening for inputting or outputting a second electric signal, and an optical signal port, one or more substrates disposed in the housing, to/from which the first electric signal is input/output and to/from which the second electric signal is input/output, an optical subassembly disposed in the housing and optically connected to the optical signal port, and a control circuit disposed in the housing and mounted on the substrate for controlling the optical subassembly, wherein the first electric signal is an electric signal input to or output from the optical subassembly, the second electric signal is an electric signal input to or output from the control circuit, and the second opening is provided on one side different from other side of the housing on which the first opening is provided.

Abstract: An optical module includes: a housing including an optical port in one of side surfaces opposite each other and an electric port in the other; an optical fiber disposed inside the housing and connected to the optical port; and an optical subassembly disposed inside the housing, optically connected to the optical fiber, and electrically connected to the electric port. The optical fiber is disposed so as to wind around the optical subassembly at least one turns in a plan view.

Abstract: The optical module includes a housing having a first opening for inputting or outputting a first electric signal, a second opening for inputting or outputting a second electric signal, and an optical signal port, one or more substrates disposed in the housing, to/from which the first electric signal is input/output and to/from which the second electric signal is input/output, an optical subassembly disposed in the housing and optically connected to the optical signal port, and a control circuit disposed in the housing and mounted on the substrate for controlling the optical subassembly, wherein the first electric signal is an electric signal input to or output from the optical subassembly, the second electric signal is an electric signal input to or output from the control circuit, and the second opening is provided on one side different from other side of the housing on which the first opening is provided.

Abstract: Provided are a printed circuit board configured to achieve reduction in impedance of a differential transmission line extending in a stacking direction, and an optical module. The printed circuit board includes a stacking-direction differential transmission line extending in the stacking direction, including: a differential signal via pair including a first signal via and a second signal via; and a plurality of conductor plate pairs each including a first conductor plate expanding outward from the first signal via, and a second conductor plate expanding outward from the second signal via. With respect to a perpendicular bisector of a center-of-gravity line segment connecting centers of gravity of the first and second signal vias, in each of the plurality of conductor plate pairs, centers of gravity of contours of the first and second conductor plates are located on inner sides of the centers of gravity.

Abstract: An optical transceiver is configured to use, as an electric signal, a digital modulation signal having a predetermined bit rate. The optical transceiver includes a case having a space for storing a component therein and a resistor being arranged between upper and lower surfaces of the space and having conductance of from 1 S/m to 1,000 S/m. The space has a height equal to or less than a wavelength in a free space of an electromagnetic wave of a frequency corresponding to the predetermined bit rate. At least a part of the height of the space is larger than a half of the wavelength. The height of the space is smaller than a width of the space. The width of the space is smaller than a depth of the space.

Abstract: An optical module is attachable to and detachable from a cage. The optical module includes a module case, a slider attached to the outside of the module case for releasing coming-off prevention from the cage, and a leakage reducing layer intervening between the module case and the slider to reduce leakage of an electromagnetic wave.