Hamamatsu-photonics K.k.

Haruhiro Funakoshi

Seiichiro Mizuno

Tetsuya Taka

Shinya Ito

A photodetecting deviceincludes a photodiode PD and an integrating circuit. The integrating circuitincludes an amplifier circuit, a capacitive element C, a first switch SW, and a second switch SW. The second switch SWis provided between a reference potential input terminal to which a reference potential Vref is input and a terminal of the capacitive element C on the inverting input terminal side of the amplifier circuit, and the second switch is opened or closed according to the level of a second reset signal Reset, and is capable of applying the reference potential Vref to the terminal of the capacitive element. Thus, an integrating circuit and a photodetecting device capable of achieving both low power consumption and high speed can be realized.

Integrating circuit and light-detection device

A photodetecting deviceincludes a photodiode PD and an integrating circuit. The integrating circuitincludes an amplifier circuit, a capacitive element C, and a second switch SW. The amplifier circuithas a driving section including a PMOS transistor Tand an NMOS transistor T, the respective drain terminals thereof being connected to each other. A first switch SWcomprising a PMOS transistor Tis opened or closed according to the level of a first reset signal Resetinput to the gate terminal. When the first reset signal Resetis at a low level, the first switch SWis closed to apply a power supply potential VDD to the gate terminal of the PMOS transistor T, thereby turning off the PMOS transistor T. Thus, an amplifier circuit, an integrating circuit and a photodetecting device capable of achieving both low power consumption and high speed can be realized.

Amplifier circuit, integrating circuit, and light-detection device

A solid-state imaging deviceincludes photodiodes PDto PD, charge-voltage converting circuitsto, pre-holding circuitsto, a transimpedance amplifier, a peak holding circuit, and a post-holding circuit. The charge-voltage converting circuitinputs charges generated at the photodiode PDand outputs a voltage value corresponding to the input charge quantity. The pre-holding circuitholds the output voltage value from the charge-voltage converting circuitand outputs the output voltage value as a current. The transimpedance amplifierinputs voltage values successively output form the pre-holding circuitstoas currents and outputs voltage values converted based on a transimpedance from the currents flowing in accordance with change quantities to the input voltage values from a reference voltage value. The peak holding circuitholds and outputs a peak hold voltage of the output voltage values from the transimpedance amplifier

Solid-state imaging device having transimpedance amplifier

A solid-state imaging deviceincludes N pixel sectionsto, transimpedance circuitsand, integrating circuitsand, and a difference arithmetic circuit. Each pixel sectionincludes a photoelectric converting circuit including a photodiode, and a first holding circuit and a second holding circuit which hold an output voltage of the photoelectric converting circuit. A voltage held by the first holding circuit of each pixel sectionis input into the difference arithmetic circuitthrough a common wire, the transimpedance circuit, and the integrating circuit. A voltage held by the second holding circuit of each pixel sectionis input into the difference arithmetic circuitthrough a common wire, the transimpedance circuit, and the integrating circuit. A voltage corresponding to a difference between the voltages output from the integrating circuitsand, respectively, is output from the difference arithmetic circuit

Solid-state imaging device with transimpedance and integrating circuits

The present invention relates to a sensor apparatus having a structure capable of obtaining digital values of signal components with a high accuracy using an A/D conversing circuit with the outputted digital value thereof having a small number of expressive bits. In the sensor apparatus, a voltage value corresponding to the amount of incident light to a photodiode is held by a holding circuit through an integrating circuit and a CDS circuit. Meanwhile, a voltage value corresponding to the amount of incident light to an adjacent photodiode is held by another holding circuit through an integrating circuit and a CDS circuit. The voltage values held by the respective different holding circuits are inputted to a subtracting circuit through different paths. The subtracting circuit outputs a voltage value corresponding to the difference between the two inputted voltage values. In an A/D converting section, the difference voltage outputted from the subtracting circuit is converted into a digital value.

Sensor apparatus

A photodetector of a wide dynamic range of incident light amount detection and low temperature dependence is provided. A first signal processing unitincludes an integrating circuit, a first holding circuit, a comparing circuit, a second holding circuit, and a latching circuit. The integrating circuithas a variable capacitor unit that is selectively set to a capacitance value among a plurality of capacitance values, accumulates charges, output from the photodiode, into the variable capacitor unit over an accumulating period that is in accordance with the capacitance value set at the variable capacitor unit, and outputs a voltage Vthat is in accordance with the amount of the accumulated charges. The comparing circuitinputs the voltage Voutput from the integrating circuit, performs a quantitative comparison of the voltage Vwith a reference voltage V, outputs a compared signal Sexpressing the result of comparison, and, when the voltage Voutput from the integrating circuitat the end of an accumulating period is less than the reference voltage V, instructs the first holding circuitto hold the voltage.

Photodetector having wide dynamic range and low temperature dependence

A signal current corresponding to an incident light intensity is output from a photodiode PD, the signal current is converted into a signal voltage by an integration circuit, and the amount of a change in signal voltage in a predetermined time is output from a CDS circuit. The difference between two voltage values output from the CDS circuitis obtained by a difference arithmetic circuitand held by a S-H circuit. In addition, the maximum value of voltage values obtained by the difference arithmetic circuitsof respective unitsis obtained by comparison circuitsof the respective units 100, a reference signal voltage generation circuit, a final coincidence determination circuit, and a reference voltage hold circuit, and on the basis of the maximum value, the A/D conversion range of an A/D conversion circuitis set.

Solid-state imaging device and distance measuring device

The signal current corresponding to an incident light intensity is output from a photodiode, and the integrating circuit stores an electric charge according to the signal current and outputs a signal voltage corresponding to the amount of the stored electric charge. The first CDS circuit stores in the integrating capacitor an electric charge corresponding to a change in the signal voltage output from the integrating circuit. Similarly, the second circuit stores in the integrating capacitor an electric charge corresponding to a change in the signal voltage output from the integrating circuit. The difference calculation circuit determines a difference between the amount of charge stored in the integrating capacitor of the first CDS circuit and the amount of charge stored in the integrating capacitor of the second CDS circuit, and outputs a signal voltage corresponding to the difference.

Photo-detecting apparatus

A drive circuit having a differential amplifier a current controller formed from an n-channel MOSFET, and a drive ability control circuit sets its output drive ability in a high state only in a signal read, and otherwise sets the output drive ability in a low state to reduce power consumption. Thus, a solid-state image sensing device which can perform a high-speed read while ensuring low power consumption and wide dynamic range can be implemented. As the drive ability control circuit, for example, a current source formed from an n-channel MOSFET and voltage switching by a drive change-over switch can be used.

Growing community of inventors

Hamamatsu, Japan

Haruhiro Funakoshi