Abstract: A display system includes a host apparatus having a video interface circuit and a display apparatus operated by feed of a video image and power from the host apparatus, and also has a communication function for receiving and transmitting data between the host apparatus and the display apparatus. In the display system, the display apparatus transmits power consumption data thereof stored in an EEPROM to the host apparatus and processes the power consumption data thereof which is received by the host apparatus, thus controlling power of the display system including the host apparatus and the display apparatus.

Abstract: Element fixing mounting portions are formed in the shape of bridge beams on both the side surfaces or the like of the first optical surface, which is disposed in confrontation with an image display element, of a Free-Form-Surface prism 61 acting as an optical element, the side surfaces being located externally of the effective light beam range of the first optical surface. Then, the optical element can be mounted on a cabinet making effective use of a space by projecting positioning bosses or the like from the mounting portions, the bosses being used when optical element is mounted on the cabinet.

Abstract: Element fixing mounting portions are formed in the shape of bridge beams on both the side surfaces or the like of the first optical surface, which is disposed in confrontation with an image display element, of a Free-Form-Surface prism 61 acting as an optical element, the side surfaces being located externally of the effective light beam range of the first optical surface. Then, the optical element can be mounted on a cabinet making effective use of a space by projecting positioning bosses or the like from the mounting portions, the bosses being used when optical element is mounted on the cabinet.

Abstract: A head mounted display system connects a portable information terminal and a head mounted display device to each other through a PC card. To the PC card is provided a second connector for supplying power and a signal from the outside which are different from power and a signal from an internal bus of the PC card, separately from a first connector of the PC card, and power and a signal to the head mounted display device are collectively supplied by a main cable connected to the first connector.

Abstract: A display system includes a host apparatus having a video interface circuit and a display apparatus operated by feed of a video image and power from the host apparatus, and also has a communication function for receiving and transmitting data between the host apparatus and the display apparatus. In the display system, the display apparatus transmits power consumption data thereof stored in an EEPROM to the host apparatus and processes the power consumption data thereof which is received by the host apparatus, thus controlling power of the display system including the host apparatus and the display apparatus.

Abstract: The present invention is directed to an apparatus using an integrated type pickup as an optical head for writing and reading optical information and capabling of writing data at high speeds. The apparatus includes a laser diode having an active layer at its intermediate position and having one area side held over a surface of a semiconductor substrate with an insulating layer interposed between the semiconductor substrate and the laser diode relative to the active layer. The laser diode has two areas with the active layer as a boundary and a constant potential is applied from a power supply to the insulating layer side of the laser diode and a transistor (laser diode drive unit) is provided to apply a modulation signal to the other area of the laser diode so that the laser diode is driven to modulate its output.

Abstract: In an optical data recording/reproducing apparatus for performing write and read operations of data by irradiating laser light onto an optical data recording medium, in order to reduce noise of a semiconductor laser, an HF oscillator is provided to superpose an HF current on a drive current to be applied to the semiconductor laser. The HF oscillator is housed in a conductive shield case together with the semiconductor laser. An LC low-pass filter is also provided in a signal line connecting the components inside and outside the shield case to prevent undesired radiation of the HF current. A write drive line and a read drive line of the semiconductor laser are separated in the shield case, and the write drive line is disconnected from the HF oscillator in at least a read mode.

Abstract: This semiconductor laser driving apparatus for driving a semiconductor laser and to be used for an optical information recording and reproducing apparatus doing at least one of recording and reproducing information in an information recording medium by using a light from the semiconductor laser comprises an emitted light amount detecting device for detecting the emitted light amount of the semiconductor laser, an output controlling device for controlling the output of the semiconductor laser on the basis of the detected output of the emitted light amount detecting device so as to be kept constant, a driving device for feeding said semiconductor laser with an operating direct current, a high frequency superimposing device for superimposing a high frequency current on the operating direct current from the driving means, a measuring device for measuring the variation of the emitted light amount of the semiconductor laser with the variation of the operating current of the semiconductor laser in the absence of the