Movable White Reference Plate and Black Shield for Color Measurement
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The color measurement accuracy of image forming apparatuses is affected by variations in the separation position of a white reference plate, leading to inconsistent measurement values due to changes in the distance between the color sensor and the white reference plate, which can cause color reproducibility issues.
Innovation Solution
An image forming apparatus with a movable white reference plate and a black member that shields light from the white reference plate during measurement, allowing the sheet to pass between the measurement unit and the black member, thereby stabilizing the measurement value by using a black backing to eliminate variations in light reflection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the white reference plate is fixed at the target position, then measurement accuracy is improved, but sheet jamming occurs due to contact between the sheet and white reference plate
Solution Approach 1:
The white reference plate is made movable between a first position (opposite the color sensor) and a second position (retracted), allowing it to be dynamically positioned based on operational requirements. This resolves the contradiction by enabling the plate to be in the measurement position only when needed, while being retracted during sheet conveyance to prevent jamming.
2Measurement precision
If the white reference plate is moved to the target position for measurement, then measurement accuracy is improved, but the device complexity increases due to attaching/detaching mechanism
Solution Approach 1:
The white reference plate is configured to be movable between positions, allowing simple attachment and detachment operations. This provides an elegant solution that improves measurement accuracy while keeping the mechanism relatively simple, avoiding the need for complex attaching/detaching mechanisms.
3Ease of operation
If the separation position of the white reference plate varies, then device operation becomes simpler, but measurement value consistency deteriorates due to distance variations
Solution Approach 1:
The white reference plate is made movable to a predetermined first position opposite the color sensor during measurement, ensuring consistent separation distance. This resolves the contradiction by providing both ease of operation (simple positioning) and measurement consistency (fixed distance control).
Solution Approach 2:
A black member is introduced as an intermediary between the color sensor and the white reference plate during sheet measurement. This black member shields light from the white reference plate, preventing it from affecting measurements and enabling consistent measurement values regardless of the white reference plate's separation position.
4Measurement precision
If the white reference plate is positioned opposite the color sensor, then light reflection measurement is improved, but light interference occurs during sheet measurement
Solution Approach 1:
The white reference plate is dynamically positioned - placed opposite the color sensor only when needed for white reference measurement, and retracted to a second position during sheet measurement to prevent light interference.
Solution Approach 2:
A black member is positioned between the color sensor and the white reference plate during sheet measurement to shield and absorb light from the white reference plate, preventing it from interfering with sheet measurements while allowing the white reference plate to remain in its measurement position.
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 suppresses the influence of differences in the separation position of the white reference plate, ensuring accurate and consistent color measurement values, thereby enhancing color reproducibility and reducing the risk of sheet jamming.
Implementation Method 1
a measurement unit configured to irradiate light on the measurement image and measure reflected light from the measurement image
Implementation Method 2
a black member provided to be movable to a third position where the black member shields light that is irradiated on the white reference plate from the measurement unit
Data Source
AI summary
An image forming apparatus includes an image forming unit configured to form a measurement image on a sheet, a measurement unit configured to irradiate light on the measurement image and measure reflected light from the measurement image, a white reference plate provided to be movable to a first position and a second position, a black member provided to be movable to a third position where the black member shields light that is irradiated on the white reference plate and to a fourth position that is retracted from the third position, and a control unit configured to, in a state in which the white reference plate is at the second position and the black member is at the third position, cause the sheet, on which the measurement image has been formed, to pass between the measurement unit and the black member and cause the measurement unit to measure the measurement image.