Print Head Control Circuit Footer Null Data for Residual Charge

The control circuit performs preliminary action by adding null image data (footer data) after the original image data. This footer data contains information that causes the light emitting elements to turn off, which is done in advance before the actual image formation completes. By preparing this turn-off command beforehand through the footer data, the system ensures that residual electric charge in capacitors does not cause unintended light emission, while keeping the control logic relatively simple.

The patent replaces the mechanical laser optical system (which requires high-speed rotating polygon mirrors and moving components) with a solid-state print head using light emitting elements such as LEDs or OLEDs. This substitution eliminates the need for mechanical scanning components, thereby reducing energy consumption and eliminating operation sounds while maintaining exposure functionality. The light emitting elements can be precisely controlled based on image data without requiring high-speed mechanical movement.

The patent replaces the bulky mechanical laser optical system including scanning mechanisms and lens groups with a compact solid-state print head. The print head uses an array of light emitting elements (LEDs or OLEDs) that can be directly positioned close to the photoconductive drum, eliminating the need for complex optical paths, scanning mirrors, and focusing lenses. This substitution dramatically reduces the physical size of the exposure system while maintaining full exposure functionality through direct light emission onto the drum surface.