Optometry Apparatus Cross Cylinder Test Initial Value Setting
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Solution Overview
Problem
The existing optometry apparatuses for cross cylinder tests face challenges in efficiently determining the astigmatic state of the eye due to unclear differences between appearance states, leading to increased examination time and potential excessive measurement precision, which hinders the smooth progression of the test.
Innovation Solution
An optometry apparatus that includes an optical system for projecting a cross cylinder test index, a cross cylinder lens to form projection images with varying astigmatic axial angles, and initial value setting means to ensure one image is clearly visible while the other is blurred, based on pre-measured astigmatic power and axial angle values, allowing for integrated training and examination, and error determination to maintain permissible measurement errors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If training screens with exaggerated differences are used for cross cylinder test training, then understanding of test contents and operating method is promoted, but examination time increases due to training duration and potential forgetting of training content
Solution Approach 1:
The patent combines the training function and examination function into a single integrated process. The initial stage of the cross cylinder test itself serves as training by presenting projection images with clearly distinguishable appearance states, allowing the examinee to understand the test methodology while performing the actual test, thereby eliminating separate training time
Solution Approach 2:
The apparatus performs preliminary setup by automatically determining appropriate astigmatic axial angles that create clearly distinguishable projection images before the examination begins. This preliminary configuration ensures that the examinee can immediately understand the test differences without requiring separate training sessions
2Speed
If clear visual differentiation of projection images is achieved in cross cylinder test, then determination speed increases, but measurement precision may become excessive leading to test progression delays
Solution Approach 1:
The apparatus dynamically adjusts the astigmatic axial angle parameter during the test to optimize the balance between visual differentiation and measurement precision. By automatically determining and changing the axial angle to appropriate values, the system ensures clear image differentiation for rapid determination while preventing excessive precision that would delay test progression
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 solution enables a more efficient cross cylinder test by allowing clear visual differentiation of projection images, reducing examination time, and preventing excessive measurement precision, thus ensuring a smoother and more accurate astigmatic axial angle measurement.
Implementation Method 1
an optical system for projecting an index for cross cylinder test to an eye to be examined
Implementation Method 2
a cross cylinder lens for forming a pair of projection images of the index by a change in astigmatic axial angle
Data Source
AI summary
The optometry apparatus includes an index projecting optical system for projecting an index for cross cylinder test to an eye for shortening examination time, a variable cross cylinder lens disposed on an optical axis of the index projecting optical system, for forming one pair of projection images of the index by switching of an astigmatic axial angle while predetermined astigmatic power is set, a joystick lever and a button used to input a result of comparison between appearance states of the pair of projection images of the index, and an initial value setting unit for determining an astigmatic axial angle of the variable cross cylinder lens to cause one of the pair of projection images of the index visually recognized and to cause the other thereof in a blurred state based on objective values of astigmatic power and an astigmatic axial angle of the eye, measured in advance, and for setting the determined astigmatic axial angle as an initial value for astigmatic axial angle measurement.