In a facsimile apparatus, a recording head and a reading head are mounted on a carriage and the carriage is reciprocated in the main scanning direction so that recording and reading of image information are performed and furthermore, a detector is mounted on the carriage for tracing and detecting slits formed in a scale plate, which is fixed to the facsimile apparatus along the movable path of the carriage, whereby the position of the carriage is determined and the moving speed and reciprocating movement of the carriage are controlled.

A copier provides output signals corresponding to subject matter on material being copied. The copier includes a light source which provides light pulses that impinge upon the material. The material provides light pulses to a light sensitive sensor in accordance with the subject matter on the material. The sensor provides electrical pulses on a one-for-one basis with the received light pulses from the material. An output circuit provides the output signals in accordance with the electrical pulses from the sensor.

A facsimile system includes a transmitter having a light source, which provides pulses of light, scans an original copy. The pulses of light impinge on the copy during each scan. A light responsive device spacially related to the copy receives pulses of light from the copy in accordance with the copy, and provides electrical pulses. A circuit in the transmitter provides output signals in accordance with the electrical pulses from the device. A pulse source in the transmitter provides synchronization pulses. The system also includes a receiver which has a network receiving the output signals and the synchronization pulses. The network provides electrical data pulses in accordance with the received output signals and electrical synchronization pulses in accordance with the received synchronization pulses. A control circuit connected to the network provides a control signal in accordance with the data pulses from the network. A laser in the receiver scans light sensitive material and provides pulses of light which strike the material in accordance with the control signal. The receiver further includes apparatus for developing material so as to provide a printed copy of the original copy.

In an optical scanning system the position of a scanning beam is determined by a grating across which the beam is traced and then retraced to start again. The first grate is detected by first filtering the relatively low frequency input signals generated as the beam traces across the grating and the relatively high frequency signals generated as the beam retraces across the grating. The filter passes the low frequency signals, excludes the high frequency signals and accentuates the changes between high and low frequency signals which occur as the beam reaches either end of the grating. By applying the filtered signal to a gating arrangement, it is possible to eliminate one plurality of the signals generated as the beam falls upon the end of the grating. The remaining plurality of signals is further applied to a gate which detects the first grate signal to the exclusion of all others for providing an accurate indication of the start of scan of the optical system.

A light beam scanner having an optical deflector which can repeatedly scan one surface to be scanned in a predetermined direction with a light beam and can start each scan at a desired time instant. A drive mechanism moves the surface to be scanned, in a direction substantially perpendicular to the direction of scanning lines formed on said surface. A signal is outputted whenever the surface to be scanned is moved a predetermined distance and a mechanism is employed for operating the optical deflector in synchronization with the output signal.