Sheet Supply Device Speed Control for Noise Reduction
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Solution Overview
Problem
Conventional sheet supply devices generate excessive sheet expansion noise due to large back tension caused by increasing speed differences between registration rollers and primary sheet supply rollers during the assistant operation, which is not adequately reduced by existing noise reduction methods.
Innovation Solution
A sheet supply device with a controller that starts the rotation of the registration rollers after the primary sheet supply rollers have stopped, and maintains a constant speed difference between the feed speeds of the registration rollers and the sheet supply rollers until the slack is flattened, preventing the speed difference from increasing and thereby reducing back tension and noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If the speed difference between registration rollers and sheet supply rollers is increased to flatten the slack of the print sheet, then the slack flattening effect is improved, but the back tension applied to the print sheet becomes excessively large causing sheet expansion noise
Solution Approach 1:
The patent applies dynamics by making the feed speed of the sheet supply rollers variable during the assistant operation. The feed speed is dynamically adjusted in multiple stages: initially set at a first feed speed to flatten the slack, then reduced to a second feed speed (lower than the first) to reduce back tension and noise, and finally stopped. This dynamic speed adjustment resolves the contradiction between achieving slack flattening and preventing excessive back tension.
Solution Approach 2:
The patent implements periodic action through multi-stage speed control of the sheet supply rollers during the assistant operation. The feed speed is periodically changed from the first feed speed to the second feed speed, and then to stopping. This periodic adjustment of operating parameters allows the system to achieve slack flattening while controlling back tension and reducing sheet expansion noise.
2Reliability
If the assistant operation is completed before the trailing edge of the print sheet passes through the sheet supply rollers, then erroneous pickup of the next sheet is prevented, but the noise reduction effect is insufficient due to large back tension
Solution Approach 1:
The patent uses dynamic speed adjustment to resolve this contradiction. The sheet supply rollers are stopped before the trailing edge passes through to prevent erroneous pickup (maintaining reliability), but the feed speed is reduced to a second speed (lower than the initial first speed) during the process to reduce back tension and minimize sheet expansion noise.
Solution Approach 2:
The patent changes the operating parameters (feed speed) of the sheet supply rollers during the assistant operation. The feed speed is changed from a first speed to a second speed (lower than the first) and then to stopping. This parameter change allows the system to maintain reliability by stopping before erroneous pickup while reducing noise through lower feed speeds.
Data Source
AI summary
A sheet supply device includes registration rollers for feeding a print sheet, a sheet supply roller for feeding a print sheet to the registration rollers, and a controller configured to control the registration rollers and the sheet supply roller. The controller is operable to start first rotation of the sheet supply roller to contact a leading edge of the print sheet to a nip between the registration rollers to form a slack of the print sheet, stop the first rotation after the slack is formed, start rotation of the registration rollers after the first rotation is stopped, start second rotation of the sheet supply roller after the rotation of the registration rollers is started, and keep a speed difference between a feed speed of the registration rollers and a feed speed of the sheet supply rollers until the slack is flattened. According to the device, noises can be reduced.