Abstract: There is provided with a cylinder apparatus comprising: a cylinder; a piston; a piston rod, one end of which is connected to the piston and the other end of which is extended outside; an external cylinder provided at an outer periphery of the cylinder so as to form a reservoir in which to seal the hydraulic liquid and gas therebetween; a base valve dividing the second chamber and the reservoir; a first check valve provided with the piston so as to allow flow of the hydraulic liquid only from the second chamber side to the first chamber side; a second check valve provided with the base valve so as to allow flow of the hydraulic liquid only from the reservoir side to the second chamber side; a flow passage connecting the first chamber with the reservoir; and an opening and closing valve opening and closing the flow passage.

Abstract: There is provided with a cylinder apparatus comprising: a cylinder; a piston; a piston rod, one end of which is connected to the piston and the other end of which is extended outside; an external cylinder provided at an outer periphery of the cylinder so as to form a reservoir in which to seal the hydraulic liquid and gas therebetween; a base valve dividing the second chamber and the reservoir; a first check valve provided with the piston so as to allow flow of the hydraulic liquid only from the second chamber side to the first chamber side; a second check valve provided with the base valve so as to allow flow of the hydraulic liquid only from the reservoir side to the second chamber side; a flow passage connecting the first chamber with the reservoir; and an opening and closing valve opening and closing the flow passage.

Abstract: A lens apparatus for moving one or more moving lenses of a lens system up to the end position of movement by a servomotor. The lens apparatus limits the moving speed of the moving lens or lenses to a value under a predetermined level. Also, the lens apparatus gradually reduces the moving speed as the moving lens or lenses approach the end position so that the moving lens element or elements can be stopped precisely at the end position.

Abstract: This specification discloses a color television camera having a test pattern projecting device. This test pattern projecting device projects a test pattern image of a desired color temperature onto an image pickup device. The color temperature of the test pattern image is adjustable.