Abstract: A honeycomb sandwich panel having an absolute value of thermal expansion coefficient smaller than an absolute value of thermal expansion coefficient obtained by using carbon fiber reinforced plastic (CFRP) is provided. The honeycomb sandwich panel includes: a first skin being a plate material made of a low expansion metal being a metal having an absolute value of thermal expansion coefficient smaller than an absolute value of thermal expansion coefficient of CFRP; a second skin being a plate material made of the low expansion metal and arranged to face the first skin; and a core made of CFRP or the low expansion metal, being bonded to the first skin and the second skin and including a plurality of tubular cells each having a hexagonal cross section, the tubular cells being formed adjacently to each other.

Abstract: An optical device can deal with a relative difference in thermal expansion coefficient between a reflecting mirror and a mirror supporting member, and can also support the reflecting mirror with a simpler structure than the conventional one. The optical device includes: a reflecting mirror including a reflecting surface to reflect light, and a supported portion disposed on a rear surface and having three supported surfaces arranged with rotational symmetry of 120 degrees around an optical axis, the rear surface being a surface of the reflecting mirror existing on the contrary side to the reflecting surface; a structural member provided on a rear side of reflecting mirror; and three supporting members, each of the three supporting members including a mirror supporting portion connected to and supporting each of the three supported surfaces, and having two ends connected to the structural member.

Abstract: A honeycomb sandwich panel having an absolute value of thermal expansion coefficient smaller than an absolute value of thermal expansion coefficient obtained by using carbon fiber reinforced plastic (CFRP) is provided. The honeycomb sandwich panel includes: a first skin being a plate material made of a low expansion metal being a metal having an absolute value of thermal expansion coefficient smaller than an absolute value of thermal expansion coefficient of CFRP; a second skin being a plate material made of the low expansion metal and arranged to face the first skin; and a core made of CFRP or the low expansion metal, being bonded to the first skin and the second skin and including a plurality of tubular cells each having a hexagonal cross section, the tubular cells being formed adjacently to each other.

Abstract: An optical device can deal with a relative difference in thermal expansion coefficient between a reflecting mirror and a mirror supporting member, and can also support the reflecting mirror with a simpler structure than the conventional one. The optical device includes: a reflecting mirror including a reflecting surface to reflect light, and a supported portion disposed on a rear surface and having three supported surfaces arranged with rotational symmetry of 120 degrees around an optical axis, the rear surface being a surface of the reflecting mirror existing on the contrary side to the reflecting surface; a structural member provided on a rear side of reflecting mirror; and three supporting members, each of the three supporting members including a mirror supporting portion connected to and supporting each of the three supported surfaces, and having two ends connected to the structural member.

Abstract: Provided is an insertion guide that performs accurate rotation correction between a shaft and a hole and phase correction between the shaft and hole. The shaft includes: a first guide portion at a distal end of the shaft having a diameter smaller than a diameter of the hole; a second guide portion, provided on a base end side of a first narrow cylindrical portion, and having a diameter smaller than the diameter of the hole and larger than a diameter of the first narrow cylindrical portion; and a third guide portion, provided at the distal end of the shaft, and is a recessed portion to be engaged with a protruding portion formed in the hole. The shaft being inclined with respect to the hole, is brought into contact with the hole at two points or less before the third guide portion is brought into contact with the protruding portion.

Abstract: A mirror replacement device includes a gripping mechanism to grip a segment mirror, a fine drive mechanism to change a position and a posture of the gripping mechanism, a lift mechanism for the segment mirror, a first detector to detect a relative position and a relative posture between a comparison object and a target object, a second detector to detect a bend of the fine drive mechanism, and a mirror replacement controller to replace the segment mirror based on detection signals output from the above-mentioned detectors. The controller determines whether the first detector can successfully perform a measurement. When it is determined that the measurement can be successfully performed, the control is performed based on the detection signal output from the first detector. When it is determined that the measurement cannot be successfully performed, the control is performed based on the detection signal output from the second detector.

Abstract: Provided is an insertion guide that performs accurate rotation correction between a shaft and a hole and phase correction between the shaft and hole. The shaft includes: a first guide portion at a distal end of the shaft having a diameter smaller than a diameter of the hole; a second guide portion, provided on a base end side of a first narrow cylindrical portion, and having a diameter smaller than the diameter of the hole and larger than a diameter of the first narrow cylindrical portion; and a third guide portion, provided at the distal end of the shaft, and is a recessed portion to be engaged with a protruding portion formed in the hole. The shaft being inclined with respect to the hole, is brought into contact with the hole at two points or less before the third guide portion is brought into contact with the protruding portion.

Abstract: A mirror replacement device includes a gripping mechanism to grip a segment mirror, a fine drive mechanism to change a position and a posture of the gripping mechanism, a lift mechanism for the segment mirror, a first detector to detect a relative position and a relative posture between a comparison object and a target object, a second detector to detect a bend of the fine drive mechanism, and a mirror replacement controller to replace the segment mirror based on detection signals output from the above-mentioned detectors. The controller determines whether the first detector can successfully perform a measurement. When it is determined that the measurement can be successfully performed, the control is performed based on the detection signal output from the first detector. When it is determined that the measurement cannot be successfully performed, the control is performed based on the detection signal output from the second detector.