| 摘要 |
PURPOSE:To provide a recording head which enables a high-quality image to be available by providing plural split current amplification circuits for individual recording elements and adjusting a current supply to the recording element through the selection of a split current amplification circuit in accordance with the output efficiency of each recording element. CONSTITUTION:A light emitting signal S is entered into an electric current control circuit 3 through a memory circuit 5 and 'AND' circuit 9 to enable an electric current amplification circuit 2 to be driven. A split current amplification circuit 21 is connected to LED 1 via an electric current detection resistor R2, whilst other circuits 22-24 are directly connected to LED 1. In addition, the split current amplification circuit 21 is driven by a light emitting signal Sn, whilst others 22-24 are subject to the optional selection of their drives by drive selection signals an, bn and cn so that LED 1 may reach a prearranged range of light emitting output. An output current from the electric current amplification circuit 2 transmits to the electric current control circuit 3 a detection value of a voltage applied to the both ends of a current value detection resistor R2 after the detection of said voltage by a voltage comparison circuit 4 so so as to allow a supply current to LED 1 to be constant. Furthermore, an output signal from a temperature sensor 10 is transmitted to each electric current control circuit 3 so that the electric current amplification circuit 2 may be controlled to obtain an output current according to temperatures. |
