Printhead Encoder Counter Reset via Carriage Stop
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Solution Overview
Problem
Inkjet printing apparatuses face challenges in stabilizing the encoder counter reset operation due to unstable encoder signals, leading to inconsistent carriage reference positions across multiple printhead control ICs, which affects image quality.
Innovation Solution
A printing apparatus generates first and second pulse signals with a phase shift, allowing multiple control units to count and control printhead movements based on these signals, and includes a stopping unit to stabilize the count value before resetting the encoder counter, ensuring simultaneous reset across all units.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a common encoder counter reset signal is connected to each printhead control IC to reset the encoder counter, then the reset operation can be performed simultaneously across all control units, but internal skew differences in manufacturing cause the reset timing to be non-simultaneous, resulting in inconsistent carriage reference positions
Solution Approach 1:
The patent applies preliminary action by stopping the carriage movement before resetting the encoder counter. This ensures that the encoder signal is stable and not changing during the reset operation, eliminating the issue of non-simultaneous reset timing caused by internal skew differences. The carriage is stopped at a predetermined position, the encoder counter is reset while the signal is stable, and then the carriage is restarted, ensuring consistent reference positions across all printhead control ICs.
2Productivity
If the encoder counter is reset while the carriage is moving, then the reset operation can be performed without stopping, but the encoder signal becomes unstable due to chattering, causing inconsistent count values across multiple control units
Solution Approach 1:
The patent applies preliminary action by stopping the carriage movement before resetting the encoder counter. This ensures that the encoder signal is stable and not changing during the reset operation, eliminating the issue of non-simultaneous reset timing caused by internal skew differences. The carriage is stopped at a predetermined position, the encoder counter is reset while the signal is stable, and then the carriage is restarted, ensuring consistent reference positions across all printhead control ICs.
3Adaptability or versatility
If sequential reset operations are performed for each printhead control IC via CPU bus, then the reset can be performed individually, but it is extremely difficult to reset all encoder counters using the same timing, leading to registration shifts and image quality deterioration
Solution Approach 1:
The patent applies preliminary action by stopping the carriage movement before resetting the encoder counter. This ensures that the encoder signal is stable and not changing during the reset operation, eliminating the issue of non-simultaneous reset timing caused by internal skew differences. The carriage is stopped at a predetermined position, the encoder counter is reset while the signal is stable, and then the carriage is restarted, ensuring consistent reference positions across all printhead control ICs.
Solution Approach 2:
The patent merges the reset operation with the carriage stop condition. By requiring the carriage to be stopped at a predetermined position before resetting the encoder counter, the patent ensures that all reset operations occur under the same stable conditions, eliminating timing differences and ensuring consistent reference positions across all control units.
Data Source
AI summary
An encoder sensor is mounted on a printhead and optically reads an encoder film. And a number of pulses of a pulse signal proportional to a moving amount of a printhead is counted and stored as a count value in a memory within multiple ICs. The count value stored in the memories is reset while the pulse signal outputted from the encoder sensor is blocked by a gate or while a region other than near a boundary between a penetration region and a non-penetration region of the encoder film is being read.