| 摘要 |
<p>When a manufacturer or a user desires to adjust a Braun tube, it is required to display a test pattern satisfying setting conditions of display modes on the Braun tube. To set the display modes of the test pattern, a plurality of horizontal synchronizing signals and a vertical synchronizing signal are generated by a timer circuit for each field. Also, display modes (for example, shape, position, size, color and luminance) of a type of characters having the same shape are set in an OSD circuit to set the display modes of the test pattern composed of the characters having the same shape. Thereafter, a composite video signal of the test pattern satisfying the display modes is produced on the basis of the horizontal synchronizing signals and the vertical synchronizing signal in the OSD circuit, and the test pattern is displayed on the Braun tube according to the composite video signal. Accordingly, because the composite video signal of the test pattern satisfying the display modes can be produced without using any private circuit, the video signal producing apparatus can be produced in a small size and at a low cost. <IMAGE></p> |
