초록 ▼

The position of a rear lens group at the time power is turned off is stored in a memory as a relative value on the basis of the positions of the rear lens group focusing on a subject at a near point and at an infinity point, respectively, with respect to the position of a zoom lens group at power of

The position of a rear lens group at the time power is turned off is stored in a memory as a relative value on the basis of the positions of the rear lens group focusing on a subject at a near point and at an infinity point, respectively, with respect to the position of a zoom lens group at power off. When power is turned on, the rear lens group is moved to the reference position by a pulse motor, and the position of the zoom lens group is detected by an encoder. After the position detection operation, the rear lens group is moved to a position calculated according to the current position of the zoom lens group and the relative value stored in the memory.

대표청구항 ▼

[ What is claimed is:] [1.] A camera apparatus including a rear focus system lens unit having a zoom lens group and a rear lens group for carrying out a focusing operation by moving said rear lens group, comprising:memory means for storing a relative value as the position of said rear lens group whe

[ What is claimed is:] [1.] A camera apparatus including a rear focus system lens unit having a zoom lens group and a rear lens group for carrying out a focusing operation by moving said rear lens group, comprising:memory means for storing a relative value as the position of said rear lens group when power is turned off on the basis of the position of said rear lens group focusing on a subject at a near point and the position of said rear lens group focusing on a subject at an infinity point with respect to said zoom lens group located at a position identical to a position of said zoom lens group when power was turned off, wherein said relative value is a ratio of: (a) a distance (Y') between an actual position of said rear lens group and another position of said rear lens group focusing on a subject at an infinity point to (b) another distance (Y) between yet another position of said rear lens group focusing on said subject at a near point and said another position of said rear lens group focusing on said subject at an infinity point,first transfer means for transferring said rear lens group to a reference position when power is turned on,position detection means for detecting the position of said zoom lens group, andsecond transfer means for transferring said rear lens group to a position calculated on the basis of the position of said zoom lens group detected by said position detection means and said relative values stored in said memory means.