| 摘要 |
The present invention is to reduce the change of the position of a picture screen due to the magnification/reduction of the picture screen and occurrence of losing a part of the picture screen. The picture screen signal of a main picture screen is switched to the picture screen signal of a sub or slave picture screen to be described later when the picture screen signal of the main picture screen is supplied to a change-over switch (2) from an input terminal (1). This picture screen signal is supplied to an image receiving tube (4) through an RGB drive circuit (3). The picture screen signal of the slave picture screen is supplied to a slave picture screen signal forming circuit (6) from an input terminal (5), reduced to an arbitrary size, taken out at the timing of an arbitrary position and the picture screen signal of the slave picture screen is formed. Further, a command signal from an command means is supplied to a microcomputer 9 through an input terminal (8). In the microcomputer (9), if the command signal mentioned above is supplied to a central processing unit (CPU) (10), a display size control signal is formed by a display size change processing means (11) (software) and at the same time a display position control signal is formed by a display position change processing means (12) (software). |
