Abstract:
An image sensor in which a plurality of pixels having at least a photodiode, a reset transistor, and source follower transistor are formed, wherein each pixel comprises an electrical-charge transfer gate transistor between the photodiode and reset transistor, and a floating diffusion region constituting a node connecting the reset transistor and transfer gate transistor is connected to the gate of the source follower transistor. Further, a photodiode region is embedded below a well region in which the reset transistor and source follower transistor of each pixel are formed. In addition, the photodiode region is not formed below at least a partial region of the floating diffusion region.
Abstract:
The present invention can be applied to a CMOS image sensor in which each pixel circuit of an active pixel sensor array includes a photoelectric conversion element for converting input light into electricity and a switch transistor for controlling the supply of a reset voltage for resetting the photoelectric conversion element to a predetermined voltage, to the photoelectric conversion element. The CMOS image sensor comprises a control circuit for assigning a control signal applied to a control electrode of the switch transistor. The control circuit outputs a first voltage much higher than a supply voltage of the CMOS image sensor so as to make an ON resistance of the switch transistor sufficiently small in the first part of a reset period of the photoelectric conversion element and outputs a second voltage lower than a supply voltage of the CMOS image sensor in the latter part of a reset period of the photoelectric conversion element.
Abstract:
A light output control circuit to update light output synchronously with input data in burst signal transmission system is disclosed. The circuit has a function of issuing light deterioration warning unerringly, which includes: a monitoring portion to detect light output emitted from a light emission element driven in accordance with transmission data; a level comparator to compare a monitoring signal outputted from the monitoring portion with a reference signal; a data detection portion to detect the existence of the transmission data; and an output controller to determine whether a light output deterioration warning is to be issued using an output signal of the data detection portion and an output signal of the level comparator.
Abstract:
An optical transmitter circuit including a light receiving element, such as a photodiode, which monitors the optical output of a light emitting element such as a semiconductor laser. A current-voltage converting circuit supplies a drive current from a drive circuit to the light emitting element and converts the output voltage of the light receiving element into voltage. An APC amplifier compares the converted output signals and a reference signal, and a hold circuit holds the output signal of the APC amplifier and uses the output signal as a current control signal of the drive circuit. A “1” continuous signal detecting circuit detects the continuation of “1” in a specified number of bits in the input data (DATA) and updates the hold value in the hold circuit.
Abstract:
A light emitting element driving circuit for high speed modulation includes an electric current source for generating a constant electric current for driving a light emitting element and an electric current switch for switching a portion of a path for an electric current flowing into the electric current source to one of a path including the light emitting element and another path excluding the light emitting element, in accordance with a data signal. The driving circuit further includes a capacitor that is charged by the application of a supply voltage to thereby boost the supply voltage, and a boost switching part. The boost switching part switches another portion of the path for an electric current flowing into the electric current source to one of a path for charging the capacitor and another path for applying the supply voltage boosted by the capacitor to the light emitting element, in accordance with a control signal corresponding to the data signal.