Abstract: An optical semiconductor device outputting a predetermined wavelength of laser light includes a quantum well active layer positioned between a p-type cladding layer and an n-type cladding layer in thickness direction. The optical semiconductor device includes a separate confinement heterostructure layer positioned between the quantum well active layer and the n-type cladding layer. The optical semiconductor device further includes an electric-field-distribution-control layer positioned between the separate confinement heterostructure layer and the n-type cladding layer and configured by at least two semiconductor layers having band gap energy greater than band gap energy of a barrier layer constituting the quantum well active layer. The optical semiconductor device is applied to a ridge-stripe type laser.

Abstract: An ink jet printer comprises a print misalignment detection sensor having a support member for supporting an LED and a PD. The support member is mounted on a cradle holding a printing head, and is open on its cradle-mounting side. The support member has U-shaped light transmitting and receiving grooves respectively forming a light transmitting path from the LED and a light receiving path to the PD. The cradle has light transmitting and receiving path ribs, each with a semicircular recess formed at its end. The two ends of the two light path ribs are respectively inserted into the two light grooves so as to cause the two light paths at the insertion positions to each have a round shape as seen in cross-sectional view. This reduces irregular reflection of light in the two light paths, thereby reducing noise in an output signal of the print misalignment detection sensor.

Abstract: In an ink jet printer using an ink cartridge having an ink tank for storing ink therein and a recording head for ejecting the ink stored in the ink tank as ink drops and forming an image on a recording paper sheet, the detection accuracy of a displacement detection sensor for detecting a displacement of printing position is improved while reducing manufacturing costs of the displacement detection sensor. The displacement detection sensor is comprised of a light emitting device for emitting diffused light, a first lens for focusing the light emitted from the light emitting device on a recording paper sheet, a second lens for focusing the light reflected by the recording paper sheet and a light receiving device for receiving the light focused by the second lens.

Abstract: The ink receiving cup is provided with a cylindrical top portion, a bearing portion into which the center shaft of rotation is fitted when the ink receiving cup is rotated at the central portion, a black ink accumulating portion where blank ink is sprayed and accumulated, and a plurality of through-holes at the outer-circumferential side and inner-circumferential side of the black ink accumulating portion for causing color inks to flow.

Abstract: An ink jet printer comprises a print misalignment detection sensor having a support member for supporting an LED and a PD. The support member is mounted on a cradle holding a printing head, and is open on its cradle-mounting side. The support member has U-shaped light transmitting and receiving grooves respectively forming a light transmitting path from the LED and a light receiving path to the PD. The cradle has light transmitting and receiving path ribs, each with a semicircular recess formed at its end. The two ends of the two light path ribs are respectively inserted into the two light grooves so as to cause the two light paths at the insertion positions to each have a round shape as seen in cross-sectional view. This reduces irregular reflection of light in the two light paths, thereby reducing noise in an output signal of the print misalignment detection sensor.

Abstract: In an ink jet printer using an ink cartridge having an ink tank for storing ink therein and a recording head for ejecting the ink stored in the ink tank as ink drops and forming an image on a recording paper sheet, the detection accuracy of a displacement detection sensor for detecting a displacement of printing position is improved while reducing manufacturing costs of the displacement detection sensor. The displacement detection sensor is comprised of a light emitting device for emitting diffused light, a first lens for focusing the light emitted from the light emitting device on a recording paper sheet, a second lens for focusing the light reflected by the recording paper sheet and a light receiving device for receiving the light focused by the second lens.

Abstract: The ink receiving cup is provided with a cylindrical top portion, a bearing portion into which the center shaft of rotation is fitted when the ink receiving cup is rotated at the central portion, a black ink accumulating portion where blank ink is sprayed and accumulated, and a plurality of through-holes at the outer-circumferential side and inner-circumferential side of the black ink accumulating portion for causing color inks to flow.

Abstract: Coal pulverized by a mill or crusher is used as a floating agent which is charged into a floating machine, together with wastewater, for example, from a wastewater treatment facility or homes which produce organic substances such as human wastes. The pulverized coal and wastewater are mixed and uniformly stirred by a stirrer in the form of an impeller or a cyclone separator while being aerated. The produced floating floc is discharged from an upper portion of a first floating machine, whereas sedimented materials are discharged from a lower portion of the first floating machine. The same process is repeated in other floating machines connected in series to the above-described first floating machine. The collected floating flocs are dewatered to produce solid cakes which are used as a fuel. The water which has been extracted to form the solid cake, is purified and discharged.