Capacitive digital caliper with separated sensor and digital circuit and manufacturing method thereof

Abstract

The invention discloses a capacitive grating-type digital caliper with a sensor and a digital circuit separated and a making method thereof. The capacitive grating-type digital caliper comprises a caliper blank, a moving grating assembly and an integrated circuit assembly, wherein the moving grating assembly comprises an ITO moving grating sensor and a flexible circuit board; the caliper blank comprises an ITO static grating and a caliper frame capable of moving on the ITO static grating; the integrated circuit assembly comprises a digital integrated circuit board, a display and a battery; the ITO static grating, the ITO moving grating sensor, the digital integrated circuit board and the display are sequentially and fixedly sleeve the caliper frame; a gap is preserved between the ITO static grating and the ITO moving grating sensor; the battery is electrically connected with the digital integrated circuit board; the ITO moving grating sensor is electrically connected with an input port of the digital integrated circuit board via a flexible circuit board; and the output port of the digital integrated circuit board is electrically connected with the display. After the ITO moving grating sensor collects caliper frame moving signals, the signals are transferred to the digital integrated circuit board, and after processed by the digital integrated circuit board, the signals are displayed via the display.

Description

technical field [0001] The invention relates to the technical field of measuring instruments, in particular to a capacitive digital caliper with a sensor separated from a digital circuit and a manufacturing method thereof. Background technique [0002] A digital caliper is usually composed of a ruler blank, a fixed grid, and a digital display moving grid. The digital display moving grid is usually composed of a moving grid sensor circuit, a digital digital integrated circuit board, and a display assembly. In order to achieve a simple structure, the moving grid sensor circuit and the digital digital integrated circuit board are usually designed and realized on the same PCB. The PCB board is usually made of copper clad laminate FR4 made of glass fiber and epoxy resin, and the fixed grid is generally made of PCB is made. For a caliper as a measuring instrument, accuracy and stability are the most important characteristics of a caliper. The precision of the existing digital ca...

AI Technical Summary

Problems solved by technology

[0004] 1. Due to the limitation of the PCB manufacturing process, the manufacturing accuracy of the fixed grid and the moving grid sensor is limited, so that the accuracy of the digital caliper is usually around 0.03mm;

[0005] 2. The PCB will usually deform with the change of ambient temperature and humidity, which will easily affect the measurement accuracy and the service life of the digital caliper;

[0006] 3. Since the moving grid sensor circuit and the digital digital integrated circuit board are designed on the same PCB board, after being fixed with the shell to form a digital display moving grid part, and then fixed on the ruler frame, it depends entirely on the machining of the ruler blank and the PCB board Precision to ensure the assembly gap between the fixed grid, not only the PCB board will be deformed during the two installation processes, but also the size of the assembly gap between the fixed grid will affect the final accuracy of the digital caliper;

[0007] 4. Since the moving grid sensor circuit and the digital digital integrated circuit board are designed on the same PCB board, the circuit layout is limited, which will inevitably lead to interference of various signals on the measurement signal, thus causing possible system errors

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