| 摘要 |
PURPOSE:To enable the application of printers of both an erecting type and an inverted type by executing a printing process in plural lens positions including the origin position of a lens, then selecting the lens position where an optimum focus is obtainable. CONSTITUTION:A prescribed magnification is first selected and the lens is focused to the calculated position obtd. by an AF curve. With this focal position as the origin position, the lens is moved to the plural lens positions within the prescribed range including this origin position and the printing process is carried out with respect to each of these positions. The AF curve is corrected in accordance with the lens position and magnification in and at which the optimum focus is obtd. among the positions and magnifications in and at which the printing process is carried out. This stage is repeated and the AF curve at the point of the time when the selected lens position and origin position coincide is determined as the true AF curve. The printing process can then be executed in the state of obtaining the optimum focus if the lens is moved in accordance with the true AF curve even when other magnifications are selected. |
