Abstract: An optical system comprises a first lens group G1 disposed in a most object side and having positive refractive power, a stop member ST disposed at an image side of the first lens group G1, and a second lens group G2 disposed at an image side of the stop member ST. A predetermined conditional expression is satisfied, whereby light beyond the maximum angle of view collected on the focal point position of a most object side lens group having positive refractive power is reduced, so that heat generated by a member in the vicinity of the focal point position is reduced.

Abstract: Provided is an optical system comprising a first lens group G1 disposed in a most object side and having positive refractive power, a stop member ST disposed at an image side of the first lens group G1, a second lens group G2 disposed at an image side of the stop member ST, and predetermined conditional expression being satisfied, whereby light outside of an effective light flux (beyond the maximum angle of view) collected on the focal point position of a most object side lens group having positive refractive power is reduced, so that heat generated by a member in the vicinity of the focal point position being reduced, thereby it being possible to prevent deformation or deterioration of the member and reduce influence on the imaging performance. An optical apparatus equipped with the optical system is also provided.

Abstract: An optical device comprises: a first holding frame holding an optical system; a second holding frame holding the first holding frame and having a groove provided on a face opposing the first holding frame; an elastic member provided between the first holding frame and the second holding frame; a position determining portion capable of determining a position of the first holding frame towards the elastic member, and provided to sandwich, with the elastic member, the first holding frame; a fixing portion is capable of fixing the first holding frame towards the position determining portion so that the first holding frame is fixed, and which is provided to sandwich, with the position determining portion, the first holding frame; and a protruding portion which has a first end fixed to the first holding frame, and another end which differs from the first end and which is inserted into the groove.

Abstract: An optical device comprises: a first holding frame holding an optical system; a second holding frame holding the first holding frame and having a groove provided on a face opposing the first holding frame; an elastic member provided between the first holding frame and the second holding frame; a position determining portion capable of determining a position of the first holding frame towards the elastic member, and provided to sandwich, with the elastic member, the first holding frame; a fixing portion is capable of fixing the first holding frame towards the position determining portion so that the first holding frame is fixed, and which is provided to sandwich, with the position determining portion, the first holding frame; and a protruding portion which has a first end fixed to the first holding frame, and another end which differs from the first end and which is inserted into the groove.

Abstract: A belt conveyor having two rollers supported at opposite ends of a support frame and a belt stretched between the rollers, in which a cylinder having an operating rod reciprocatable in a moving direction of the belt is mounted on the support frame; a drum including a one way clutch mechanism therein and having a sprocket wheel fixed therearound is fitted around a transmission shaft integral with one of the rollers; a chain is wound around the sprocket wheel mounted around the drum including the one way clutch mechanism therein; and the chain is connected to the operating rod of the cylinder.When the operating rod of the cylinder reciprocates, the chain is reciprocated by the operating rod. This reciprocatingly rotates the sprocket wheel mounted on the drum in which the one way clutch mechanism is installed. The rotation in a predetermined direction is transmitted, through the one way clutch mechanism, to the transmission shaft of the roller around which the belt is wound.

Abstract: A ratchet type quick feeding mechanism for an automobile pantograph jack including a round bar having a ratchet screw portion, a pawl member for engaging the teeth of the ratchet screw portion, a connecting block carrying a horizontal shaft on which the pawl member is pivotally supported, and pantograph link assemblies for changing the height of the jack by horizontal shift of the connecting block.