Nippon Oil Company

Kunihiko Sato

Kazuo Morohashi

Hidetoshi Takahashi

Hidetoshi Takagi

This invention is to provide a lightweight, inexpensive reflecting mirror. A reflecting layer is formed on the front surface of a carbon fiber-reinforced plastic substrate. An reflecting mirror includes a first substrate consisting of a carbon fiber-reinforced plastics, a reflecting layer formed on the front surface of the first substrate, a second substrate formed on the rear surface of the first substrate, an edge member formed at edges of the first and second substrates, and a foamed body filled in a space defined by the first and second substrates and the edge member. The second substrate and the edge member preferably consist of a carbon fiber-reinforced plastics.

Reflecting mirror

The present invention provides a CFRP-made optical cylinder comprising, as the main CFRP layers, (a) CFRP layers containing a carbon fiber arranged in a direction substantially parallel to the cylinder axial direction and (b) CFRP layers containing a carbon fiber arranged in a direction making an angle of substantially.+-.(40.about.50) degree to the cylinder axial direction, in which cylinder at least 50% by weight of the carbon fiber arranged in a direction substantially parallel to the cylinder axial direction has a linear expansion coefficient of -1.times.10.sup.-6 /.degree.C. or less and at least 50% by weight of the carbon fiber arranged in a direction making all angle of substantially.+-.(40.about.50) degree to the cylinder axial direction has a linear expansion coefficient of -1.times.10.sup.-6 /.degree.C. or less, and which cylinder has a linear expansion coefficient of -0.5.times.10.sup.-6 /.degree.C. to 0.5.times.10.sup.-6 /.degree.C. in the axial direction. In the present optical cylinder, the influence by the change in atmospheric temperature is very small. Further, in the production of the present optical cylinder, it has no distortion when subjected to heating and subsequent cooling to room temperature for molding, because it is well balanced in rigidity and strength.

CFRP-made optical cylinder

The present invention provides a CFRP-made optical cylinder comprising (a) CFRP layers containing a carbon fiber arranged in a direction substantially parallel to the cylinder axial direction and (b) CFRP layers containing a carbon fiber arranged in a direction nearly orthogonal to the cylinder axial direction, in which cylinder the carbon fiber arranged in a direction substantially parallel to the cylinder axial direction has a minus thermal expansion coefficient and the cylinder axial direction has a thermal expansion coefficient of -0.5.times.10.sup.-6 /.degree.C. to 0.5.times.10.sup.-6 /.degree.C. In the present optical cylinder, a sharp image can be maintained without making the correction of the optical axis even when the atmospheric temperature changes largely.

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Yokohama, Japan

Kunihiko Sato