Computer optometry unit

Abstract

The invention relates to a computer optometry unit which is characterized by comprising a base assembly, a control assembly, a screen assembly, a head support assembly, a three-dimensional translation assembly and a monitoring assembly. The control assembly comprises an electrical control hardware portion and an electrical control algorithm software portion, the electrical control hardware portion drives a stepping motor by subdivision driving of an integrated chip through a high-performance microcontroller and a constant current chopping two-phase stepping motor, the microcontroller inputs pulse and level signals to control the running step number and the direction of the stepping motor, the electrical control software algorithm simulates acceleration and deceleration S-shaped curves by an S-shaped curve acceleration and deceleration control method, simulates a corresponding speed change step curve and calculates the frequency and the execution step number of each discrete point, a PWM (pulse width modulation) functional module inside the microcontroller is configured according to frequency parameters to output square-wave signals under corresponding frequency, the execution step number of the motor is accumulated in the output process, and the stepping motor reaches a specified position after all frequency pulses are outputted.

Description

technical field [0001] The invention relates to an eye measuring device, in particular to a computer optometry instrument. Background technique [0002] The current computer refractor adopts an objective measurement method, which projects an infrared image onto the fundus of the human eye, generates a scattering image on the retina of the human eye, and calculates the diopter of the eye objectively by analyzing the measurement image collected by the CCD. [0003] During the measurement, the operator gently controls the front, back, left, right, up and down movement of the instrument, captures the pupil of the subject's eye, aligns it with the pupil of the eye, presses the measurement button, and the measurement result will be displayed immediately on the screen. [0004] The accuracy of the computer refractometer is affected by many factors, such as poor coordination between the head and eyes of the subject, moving around, and not focusing enough on the target in the refrac...

AI Technical Summary

Problems solved by technology

[0004] The accuracy of the computer refractometer is affected by many factors, such as poor coordination between the head and eyes of the subject, moving around, and not focusing enough on the target in the refractor, resulting in insufficient relaxation and adjustment, which will inevitably affect the accuracy of the diopter test results Sex, and even the difference in the degree of repeated inspection is large, especially for children, the error of the computer optometry test is large, and the diopter cannot even be checked.

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