Thermal Printer Head Pressurization Mechanism
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Solution Overview
Problem
Existing thermal printer configurations face challenges in maintaining desired contact pressure between the thermal head and platen roller, affecting print quality and operability, as both functions are often handled by a single urging member, leading to inadequate force distribution and increased operational complexity.
Innovation Solution
The solution involves using separate urging members for platen holding and head pressurization, with the urging member acting on the lock mechanism to provide a predetermined platen holding force and additional head pressing members ensuring a desired head pressurizing force, reducing the number of components and improving operability while maintaining print quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single urging member is used for both platen holding and head pressurization, then the number of components is reduced, but the desired urging force for each function cannot be applied independently
Solution Approach 1:
The patent divides the single urging member into two separate urging members: a first urging member for platen holding and a second urging member for head pressurization. This segmentation allows independent control of urging forces for each function, resolving the contradiction between component reduction and force control reliability.
Solution Approach 2:
The first urging member is designed to serve dual purposes: it provides both platen holding function and contributes to head pressurization. This multi-functionality approach maintains component efficiency while enabling independent force control through the addition of a dedicated second urging member for head pressurization.
2Stress or pressure
If the urging force of the urging member is increased to secure head pressurization, then contact pressure is improved, but operability of mounting/removing platen roller is lowered
Solution Approach 1:
By separating the urging functions into two independent urging members, the patent allows the first urging member to provide only the necessary platen holding force, while the second urging member provides the additional head pressurization force. This segmentation ensures that the platen roller can be mounted and removed easily without requiring excessive force to overcome high spring pressure.
Solution Approach 2:
The patent applies different urging forces locally to different functions: a moderate holding force for platen security and a stronger pressurization force for print quality. This localized force application optimizes both operability and print quality without compromise.
3Ease of operation
If the urging force of the urging member is reduced to improve operability, then mounting/removing platen roller becomes easier, but head pressurization becomes insufficient
Solution Approach 1:
The patent resolves this contradiction by segmenting the urging functions: the first urging member provides sufficient holding force for secure platen mounting with manageable operation force, while the second urging member independently provides the additional force needed for adequate head pressurization and contact pressure.
Solution Approach 2:
The patent combines the holding function and pressurization function in a coordinated manner where the first urging member handles platen security and the second urging member enhances head pressurization. This combination allows both operability and contact pressure requirements to be satisfied simultaneously.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This configuration allows for independent adjustment of head pressurizing force, enhances operational stability, and reduces the number of components, thereby improving print quality and operability while maintaining design flexibility and cost-effectiveness.
Implementation Method 1
an urging member configured to urge the lock mechanism toward a lock position at which the platen roller is rotatably held and configured to urge the head support body toward a direction in which the thermal head comes closer to the platen roller
Implementation Method 2
springs configured to press the platen roller and the thermal head toward a direction in which the platen roller and the thermal head are brought into contact with each other
Data Source
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AI summary
A printing unit comprises: a main body frame; a platen roller removably mounted to the main body frame; a lock mechanism pivotably supported by the main body frame between a lock position at which the platen roller is rotatably held by the main body frame and an unlock position at which the platen roller is removable from the main body frame; a thermal head to be brought into pressure contact with an outer circumferential surface of the platen roller; a head support body configured to support the thermal head, the head support body being pivotably supported by the main body frame in such directions that the thermal head and the platen roller are brought closer to and away from each other; an urging member interposed between the lock mechanism and the head support body, the urging member being configured to urge the lock mechanism toward the lock position and urge the head support body in such a direction that the thermal head is brought closer to the platen roller; and a head pressing member configured to press the head support body in such a direction that the thermal head is brought closer to the platen roller.