| 摘要 |
<p>PURPOSE:To facilitate an easy operation and to prevent the generation of an error when a switching operation is performed among plural CRTs by means of a light pen and a keyboard, by picking a part of the desired CRT screen with the light pen and switching it automatically. CONSTITUTION:CRT displays 1a and 1b and CRT screens 1c and 1d are switched by means of a keyboard 10 and a light pen 3. The displays 1a and 1b are connected to controllers 2a and 2b respectively via connection lines 11 and 14. A mark *, for example, is displayed at a part of the CRT screen which is connected presently. When the display 1a is connected to the CRT screen, an area of the sceen 1d is picked up with the pen 3. Thus a signal is supplied to a light pen interruption detecting circuit 6a within the controller 2a and then sent back to a detecting circuit 6b after detecting the signal is not sent from the own side. The circuit 6b drives switching devices 5a and 5b to switch the pen 3 and the keyboard 10. This facilitates the switching operation and prevents the generation of errors.</p> |
