Liquid Discharge Head Offset Flow Paths for Thermal Uniformity

The discharge port array is divided into multiple discharge port groups (first discharge port group, second discharge port group, etc.) arranged in the first direction. Each group has its own supply opening and collecting opening positioned at different locations in the second direction, segmenting the flow path to distribute temperature effects across multiple zones rather than creating a single temperature gradient.

Different discharge port groups are positioned at different locations in the second direction relative to the supply and collecting openings. This creates local variations in flow path characteristics, where discharge port groups closer to supply openings receive fresher ink while those closer to collecting openings receive ink that has circulated longer, thereby distributing temperature non-uniformity across the array rather than concentrating it.

The supply openings and collecting openings are positioned asymmetrically in the second direction relative to the discharge port groups. Specifically, the first supply opening is positioned at a different location than the second supply opening, and similarly for collecting openings. This asymmetric arrangement creates different flow path lengths and characteristics for different discharge port groups, balancing the temperature distribution across the array.

The patent introduces a second direction (orthogonal to the first direction where discharge ports are lined up) as a new dimension for positioning supply and collecting openings. By arranging openings at different positions in this second direction, the patent creates a two-dimensional flow path configuration that distributes temperature effects more evenly across the discharge port array, preventing concentration of temperature non-uniformity in a single location.