Fingerprint Time Clock

Overview

A fingerprint time clock is the terminal employees punch in and out on. Instead of a card or signature, it identifies each person by a fingerprint, so attendance records cannot be passed to a coworker. It mounts on a wall by the entrance and pushes every punch to payroll or HR software over the network.

The biometric front end is the Optical Fingerprint Sensor: a finger pressed on a glass prism is lit from beneath and imaged by a small camera, capturing the ridge pattern for matching. For staff whose prints read poorly, or for visitors, the terminal also accepts a badge at the RFID Reader or a PIN on the Numeric Keypad. A small touch Touch Display shows each person's name and punch status, and the Speaker confirms with a voice prompt.

All of this runs on the Main Logic Board, a Linux SoC that holds the enrolled-template database, runs the matching engine, timestamps punches against a battery-backed clock, and syncs records over Ethernet or Wi-Fi. An Backup Battery Pack keeps the clock and logs alive through power cuts, and the whole unit hangs on a steel Wall Mount Bracket.

How it works

When a worker presses a finger on the Optical Fingerprint Sensor, the LED lights the fingertip through the prism and the imager captures the ridges. The Main Logic Board extracts the print's minutiae, the ridge endings and bifurcations, into a compact template and compares it against every enrolled template in its database (1:N matching). A match in under a second identifies the employee.

The board then timestamps the punch against its real-time clock, writes the record to flash, and shows the name and in/out status on the Touch Display while the Speaker announces the result. The same record is queued for upload to the attendance server over the network. If the fingerprint fails, the worker can badge at the RFID Reader or enter an ID on the Numeric Keypad instead, both of which feed the same punch logic. Should mains power drop, the Backup Battery Pack keeps the clock running and protects buffered punches until the terminal can sync again.