Method and inkjet printer with automatic compensation of the thickness of a printable substrate

What is this patent about?

’062 is related to the field of inkjet printing, specifically addressing the mechanical challenges of printing on three-dimensional or variable-thickness items like garments, ceramics, or industrial parts. In traditional digital printing, maintaining a precise and consistent distance between the print head and the substrate surface is critical for image clarity. However, when substrates vary in thickness, operators are often forced to perform time-consuming manual height adjustments or use complex motorized sensors to prevent the print head from crashing or losing focus.

The underlying idea behind ’062 is a passive, mechanical thickness compensation mechanism that uses a spring-loaded support surface to automatically align the top of any substrate with a fixed printing plane. Instead of moving the print head to match the object, the invention utilizes a floating table that is biased upward. By using a rigid frame to press the substrate down against this upward force, the top surface of the object—regardless of its internal thickness—is trapped at exactly the same height every time.

The claims of ’062 focus on a carriage assembly comprising a slidable tray with fixed reference edges, a vertically movable support table, and a biasing means that pushes the table toward a raised position. The system is defined by the interaction between this spring-loaded table and a removable stop frame. When the frame is clamped onto the tray, it forces the table and the substrate downward until the frame seats against the reference edges, ensuring the printable surface is perfectly flush with the predefined printing plane.

In practice, the system works by allowing an operator to place an item on the table while it is in a fully raised, accessible position above the tray edges. As the operator snaps the stop frame into place, the articulated cross journals or gas springs underneath the table compress. This action effectively sandwiches the substrate between the table and the frame. Because the frame’s position is fixed relative to the tray, the top surface of the substrate is always held at the same distance from the inkjet nozzles, whether the material is a thin silk sheet or a thick sweatshirt.

This approach differs from prior solutions by eliminating the need for electronic sensors or manual screw adjustments to calibrate height. By utilizing a removable carriage that can be prepared away from the printer, the invention also enables a continuous workflow where one tray is being loaded while another is inside the machine. The mechanical simplicity of the clamping frame ensures that the substrate is not only at the correct height but also held in a stretched, flat state, which significantly reduces the risk of registration errors or print artifacts caused by fabric wrinkles.