Projector Focus Adjustment via Evaluation Value Feedback
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Solution Overview
Problem
Projectors face challenges in displaying the sharpness of focus during focus adjustment, making it difficult for users to determine the focusing state, as the visibility of the focus is not sufficient, unlike in camera systems where focus evaluation values are clearly displayed.
Innovation Solution
A projector system that includes a projection section, focus adjustment section, evaluation value calculation section, and control section to calculate and display the contrast of shot images, projecting images representing the difference in evaluation values before and after focus adjustment, using storage to obtain maximum values, and outputting sounds to indicate focus achievement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If focus adjustment is performed manually in a projector, then the user can adjust the focus, but the visibility of the image representing sharpness is insufficient to determine the focusing state
Solution Approach 1:
The patent implements a feedback mechanism by displaying the evaluation value (sharpness metric) during focus adjustment. The control section calculates the evaluation value based on the shot image and displays it, allowing the user to see real-time feedback about the focusing state. This resolves the contradiction by providing the necessary information about sharpness while maintaining ease of manual focus adjustment.
Solution Approach 2:
The patent introduces an intermediary element - the evaluation value display - that mediates between the focus adjustment operation and the user's perception. Instead of directly showing the image sharpness (which is difficult to perceive), the system displays an evaluation value that represents sharpness, making the focusing state information available to the user during manual adjustment.
2Loss of information
If the image itself is used to represent sharpness of focus, then focus information can be displayed, but the visibility of the image representing sharpness is not sufficient when focus is not achieved
Solution Approach 1:
The patent creates a copy of the focus information in the form of an evaluation value display. Instead of relying on the image itself to convey sharpness information (which has insufficient visibility), the system displays a separate evaluation value that copies and represents the sharpness information in a more visible and easily perceivable format.
3Productivity
If focus adjustment is performed without visual feedback, then the operation is simple, but the user cannot determine when focus is achieved
Solution Approach 1:
The patent implements feedback by displaying the evaluation value during focus adjustment, enabling users to determine when focus is achieved. The control section continuously calculates and displays the evaluation value, providing real-time information about the focusing state. This allows users to quickly identify the focused state without unnecessary delays.
Solution Approach 2:
The patent utilizes visual changes in the evaluation value display to indicate focus achievement. When the evaluation value reaches its maximum (indicating optimal focus), the display shows this through visual changes such as the evaluation value becoming full brightness or changing color, providing clear feedback to the user about focus achievement.
Data Source
AI summary
A projector includes a projection optical system adapted to project an image on a screen, a lens drive section adapted to perform a focus adjustment in accordance with an operation, a shooting section adapted to shoot the screen, an evaluation value calculation section adapted to calculate an evaluation value used to evaluate contrast of a shot image of the shooting section, and a display control section adapted to make the projection lens project an image, which corresponds to a difference between the evaluation value calculated by the evaluation value calculation section after the focus adjustment and a maximum value of the evaluation values having been calculated by the evaluation value calculation section before the focus adjustment, on the screen in a case in which the lens drive section has performed the focus adjustment in accordance with the operation.