Printer Control Unit Velocity and Standby Management
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Solution Overview
Problem
In serial printers, the 'kicking phenomenon' causes sheet position accuracy issues due to increased paper feed, leading to density unevenness in printing results as the paper feed velocity is slowed to mitigate this effect, resulting in region-by-region differences in ink drying times.
Innovation Solution
A printing apparatus and method that employs a control unit to manage paper feed velocity and standby times across multiple passes, slowing the paper feed when the trailing end passes through a low-velocity region and adjusting standby times to minimize density unevenness by gradationally changing drying times across printed regions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the paper feed velocity is slowed to suppress the kicking phenomenon, then the sheet position accuracy is improved, but the drying time of ink becomes different region by region causing density unevenness
Solution Approach 1:
The printing medium is divided into multiple regions (first region where trailing end passes through first transport member, second region, third region) and the paper feed velocity is controlled differently for each region. The control unit sets slower velocity for the first region and normal velocity for the third region, creating region-specific feed control to manage drying times and prevent density unevenness while maintaining position accuracy.
Solution Approach 2:
The paper feed velocity is made variable rather than constant. The control unit dynamically adjusts the feed velocity based on the current printing region and pass number. In the first region, slower velocity is applied; in the third region, normal velocity is applied. This dynamic adjustment allows the system to optimize both position accuracy and drying time uniformity across different zones.
2Object-affected harmful factors
If the paper feed velocity is slowed for a certain period of time, then the kicking phenomenon is suppressed, but the drying time of ink becomes different region by region causing density unevenness
Solution Approach 1:
Different paper feed velocities are applied to different regions of the printing medium. The first region (where the trailing end passes through the first transport member) receives slower feed velocity to suppress kicking, while the third region receives normal velocity. This local differentiation ensures that the harmful kicking effect is suppressed where needed without causing widespread density unevenness.
Solution Approach 2:
The control unit changes the paper feed velocity parameter based on the printing region and pass number. By adjusting this critical parameter dynamically, the system suppresses the kicking phenomenon in the first region while maintaining normal drying characteristics in the third region, thereby preventing density unevenness.
3Reliability
If multi-pass printing is performed with region-specific velocity control, then density unevenness is reduced, but the printing time increases
Solution Approach 1:
The control unit applies slower paper feed velocity only partially - specifically only during the first region printing period - rather than throughout the entire printing process. This partial application of velocity control suppresses kicking and manages drying times without unnecessarily extending the overall printing cycle time.
Solution Approach 2:
The printing process is divided into periodic phases (first period for first region, second period for second region, third period for third region), and the control unit applies different velocity control strategies to each phase. This periodic differentiation allows efficient time management while ensuring density uniformity where required.
Data Source
AI summary
A control unit configured to perform multi-pass printing provided that a region of a printing medium including a first region, a region downstream of the first region is a second region, and a region downstream of the second region is a third region, in a first period in which the first region is a target of printing, causes a velocity of paper feed to be slower than in a third period in which the third region is a target of printing; in the first period, causes a standby time of the printing head to be longer than in the third period; and in a second period in which the second region is a target of printing, changes the standby time so that the standby time approaches the standby time in the first period from the standby time in the third period as the first region approaches the printing head.