Victor Company of Japan, Limited

Other

Takahiro Kaneko

Minoru Ohyama

Takayoshi Hiraga

Toshinari Hayashi

An optical pickup includes a first laser beam light sourcefor emitting a light flux of a first wavelength, a diffraction gratingand an optical devicehaving a second laser beam light sourcefor emitting a light flux of a second wavelength and a hologram element. In operation, the diffraction gratingdiffracts the backward light of the first wavelength at a predetermined angle. The hologram elementdiffracts the backward light of the second wavelength by a first areaand also diffracts the backward light of the first wavelength at a reversed-polarity angle to the first areaby a second area

Optical pickup and optical device

An optical-pickup hologram element has six regions on an x-y plane, divided as follows: the first region with a first line (an x-axis) and a second line that connects points (&#x2212;xa, 0) and (&#x2212;xb, yb); the second region with the first and second lines and a third line connecting points (xa, 0) and (xb, yb); the third region with the first and third lines; the fourth region with the first line and a fourth line connecting the point (xa, 0) and a point (xb, &#x2212;yb); the fifth region with the first and fourth lines and a fifth line connecting the point (&#x2212;xa, 0) and a point (&#x2212;xb, &#x2212;yb); and the sixth region with the first and fifth lines (xa&#x3c;xb and &#x2212;xb&#x3c;&#x2212;xa). The second and fifth, and the other regions are given astigmatism at different angles to the second line.

Optical pickup

In a photo pickup device, an incident areafor a reflection light of a light spot is divided into four areasby parting linesmaking axial-symmetrical angles with a direction Y of a projected track on an optical disc. In these areas, the so-divided areasare formed so as to diffract the light in one or more directions in a range of 90 degrees&#xb1;20 degrees to the direction Y and impress misalignment on each diffraction light. In each diffraction light, two focal lines produced due to the astigmatism make approx. 45 degrees with the direction Y of the projected track. Further, the divided areasare characterized by diffracting the light in one or more directions in a range of 90 degrees&#xb1;20 degrees to the direction Y.

Optical pickup device

The display re-imaging system comprises a monitor ( ) for display re-imaging and a television camera ( ) having a display of the monitor for display re-imaging in a part of a field of view of the television camera. The monitor ( ) consists of an LCD monitor comprising a back light ( ) including cold cathode fluorescent lamps ( - to - ) as a light source having a prescribed color temperature, and a non-self-light-emitting-display panel ( ) for selectively transmitting light emitted from the back light according to an image signal. The, color temperature of the cold cathode fluorescent lamps ( - to - ) is adjusted to a level corresponding to a reddish color to match with the color temperature of the re-imaging environment. According to such a monitor ( ) for display re-imaging and a display re-imaging system, because the color temperature correction is performed on the back light itself, there is no problem of reduced brightness as was the case with the conventional RGB and filter adjustment methods that were used in connection with the conventional monitors for display re-imaging and display re-imaging systems using LCD panels. As a result, the monitor has a thin profile, consumes little power, and provides a bright display as compared to the conventional CRT display.

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Yokohama, Japan

Takahiro Kaneko