| 摘要 |
PURPOSE:To enable improvement of variations in resistance at the time of energization, by a construction wherein switching elements are divided into a plurality of groups, and the elements in each of the groups are led to a single adjusting resistance element. CONSTITUTION:For each of driver IC chips 1, 2..., a variable adjusting resistance element Ra is connected in series with a plurality of switching transistors Tr in the group corresponding to the relevant chip, whereby variations in resistance at the time of energization can be absorbed, and a heating voltage VH2 can be made constant. Accordingly, the need for an operation for measuring the resistance at the time of energization and sorting the chips prior to mounting the driver IC chips 1, 2... can be eliminated, the problem of density variations in a sub-scanning direction in halftone full-area printing is solved, and image quality of gradated images is enhanced. Further, the potentials of bases and gates of the switching elements relative to the ground potential are raised, so that malfunction under the effects of noises or the like can be prevented from occurring. |
