Time clocks or attendance time recorders are used extensively in industry as a means for automatically stamping the entrance and exit times on an employee's record card. The time record is used as a basis for calculating the pay due to hourly employees and as a record of the employee's tardiness, lunch breaks and departure time.
While the time clock automatically positions the record card and embosses the time stamps therein to preclude overstrikes and fraudulent alteration, no means is provided to establish that the time card was actually stamped or punched by the employee identified on the card, i.e., it is possible for one employee to punch in and/or out for another, thereby permitting the other employee to arrive late, leave early or even miss a day without detection by the time clock system.
While it is possible to prevent such abuses by assigning an attendant to the time clock, such is expensive and is only as reliable as the attendant.
Other proposals have been made to prevent time clock fraud but these are unsatisfactory because they require that the modern expensive time clocks, which are now in widespread use because of their reliability, be replaced with different clocks which may be less reliable and which involve additional expense. For example, U.S. Pat. No. 47,266 relates to a revolving time chart which must be signed when the time is recorded, while U.S. Pat. No. 1,395,400 relates to system in which the employee's fingerprint is recorded with the punch time.