Olympus Corporation

Denso Corporation

Yoshio Hagihara

Susumu Yamazaki

Masashi Saito

Yuichi Gomi

Yasunari Harada

Nana Akahane

Seisuke Matsuda

Shigeru Hosokai

Makoto Ono

Hiroshi Itoh

Yusaku Koyama

An imaging device includes a voltage generation circuit and an output circuit. The voltage generation circuit includes a first capacitance element including a fifth terminal. The voltage generation circuit is configured to provide the fifth terminal with a first voltage in accordance with a power source voltage so as to store an electric charge in the first capacitance element. The voltage generation circuit is configured to increase a voltage of the fifth terminal by a second voltage in accordance with the power source voltage so as to generate a control voltage having a greater absolute value than an absolute value of the power source voltage. The output circuit is configured to output the control voltage to at least one of a gate terminal of a reset transistor of a pixel and a gate terminal of a transfer transistor of the pixel.

Imaging device and endoscope system

A booster apparatus includes a voltage conversion control circuit configured to generate second power supply voltage, based on the ground voltage, first power supply voltage, and a driving clock signal. The voltage conversion control circuit includes: a booster circuit configured to generate the second power supply voltage based on an input booster clock signal; a clock buffer configured to generate the booster clock signal and output the generated booster clock signal to the booster circuit; and a voltage comparator that includes: a first voltage generation circuit configured to generate a first signal with a first voltage level; a second voltage generation circuit configured to generate a second signal with a second voltage level; and a comparator configured to compare the first voltage level and the second voltage level and control input of the driving clock signal to be supplied to the clock buffer based on a comparison result.

Booster apparatus, imaging apparatus, endoscope and voltage conversion control method

An AD conversion device includes a comparison circuit, an upper-level DA conversion circuit, a level shift circuit, a lower-level DA conversion circuit, and a correction device. The comparison circuit includes a first terminal and a second terminal. The comparison circuit is configured to compare a first voltage level of a signal input to the first terminal with a second voltage level of a signal input to the second terminal. The upper-level DA conversion circuit includes a plurality of capacitance elements electrically connected to the second terminal. Capacitive values of the plurality of capacitance elements are weighted by binary numbers. The level shift circuit includes one or more capacitance elements electrically connected to the second terminal. The lower-level DA conversion circuit includes a plurality of capacitance elements electrically connected to the second terminal.

Ad conversion device, imaging device, endoscope system, and ad conversion method

In an imaging system, a differential signal transmission circuit is configured to output a first signal to a first signal line in an image output period and is configured to output a second signal to a second signal line in the image output period. The first signal and the second signal are included in a differential signal. A signal output circuit is configured to output a second clock signal to the first signal line in a blanking period different from the image output period and is configured to output a second control signal to the second signal line in the blanking period. In a PLL, connection between a charge pump and a loop filter is controlled on the basis of the second control signal output to the second signal line.

Imaging system and endoscope system

In an AD conversion circuit, a comparator is configured to compare a first voltage of a first input terminal with a second voltage of a second input terminal. A reset circuit is configured to reset a voltage of the first input terminal of the comparator and a voltage of the second input terminal of the comparator when a second analog signal is input to the first input terminal of the comparator. A first signal generation circuit is configured to generate the second analog signal having a third voltage higher or lower than a voltage of a first analog signal. The first analog signal is input to the first input terminal of the comparator after the voltage of the first input terminal of the comparator and the voltage of the second input terminal of the comparator are reset.

AD conversion circuit, imaging device, and endoscope system

An endoscope system includes an imaging element, a voltage-current conversion circuit, a first coaxial cable, and an impedance conversion circuit. The imaging element generates a first voltage. The voltage-current conversion circuit is disposed inside or outside the imaging element and converts the first voltage into a first current. The first coaxial cable has a first conductor and a second conductor. The second conductor is disposed outside the first conductor. The first current is transmitted through the first conductor. The first current transmitted through the first conductor is input to the impedance conversion circuit. The impedance conversion circuit outputs a second current according to the first current. A second voltage according to the first current is input to the second conductor.

Endoscope system

An AD conversion circuit includes a comparison circuit, a first DA conversion circuit including a plurality of resistance elements, and a first voltage output circuit. A comparator of the comparison circuit outputs a signal that represents a result of comparing a first voltage of a first input terminal with a second voltage of a second input terminal. A first combined resistance value of the first DA conversion circuit and the first voltage output circuit seen from a second terminal of the first capacitance element is a first value when the first capacitance element holds a first signal. The first combined resistance value is a second value when the comparator compares the first voltage with the second voltage. The first value is less than the second value.

A signal transmission circuit includes an impedance conversion circuit and a current-voltage conversion circuit. A first current is input to the impedance conversion circuit. The impedance conversion circuit outputs a second current according to the first current. The current-voltage conversion circuit converts the second current output from the impedance conversion circuit into a voltage. The impedance conversion circuit includes a first current source and a current output circuit. The first current source generates a reference current. The current output circuit outputs the second current according to the difference between the first current and the reference current or the sum of the first current and the reference current.

Signal transmission circuit and endoscope system

An imaging device includes a plurality of pixels, a reference current generation circuit, a differential current generation circuit, a reference voltage generation circuit, a conversion circuit, and an output circuit. The differential current generation circuit generates a differential current according to a difference between a pixel current and a reference current. The conversion circuit converts the differential current into an output voltage on the basis of a first reference voltage. A second reference voltage is higher than the tint reference voltage when the output voltage at the time of resetting of the pixels is higher than the output voltage at the time of exposure of the pixels. The second reference voltage is lower than the first reference voltage when the output voltage at the time of resetting of the pixels is lower than the output voltage at the time of exposure of the pixels.

An encoding circuit includes a clock generating unit having a delay circuit in which n (n is a power of 2) delay units are connected together a latch unit configured to latch the plurality of delayed signals; and an encoding unit configured to encode state of each of the plurality of delayed signals, wherein the encoding unit encodes the state of each of the plurality of delayed signals by performing: a first operation of determining a position at which logic states of two or more delayed signals in a signal group change from High to Low, a second operation of determining a position at which logic states of two or more delayed signals in the signal group change from Low to High, and a third operation of determining that logic states of two or more signals including at least one delayed signal in the signal group are predetermined states.

Encoding circuit, ad conversion circuit, imaging device, and imaging system including a delay circuits having opposite polarity output terminals

An imaging device includes an imaging unit, a reference signal generation unit, m (m is an integer of 3 or more) number of column delay units, and a plurality of column AD conversion units. The plurality of column delay units is arranged so as to correspond to two or more and less than m of the column AD conversion units. Each of the plurality of column delay units includes a first delay circuit. The first delay circuit generates a plurality of first delay clocks. The column AD conversion unit includes a comparison unit, a latch unit, and a counter unit. The comparison unit compares a pixel signal with a reference signal, and outputs a control signal corresponding to a comparison result. The latch unit includes a plurality of latch circuits that latches the plurality of first delay clocks on the basis of a state change of the control signal.

Imaging device and imaging system

A first voltage line supplies a constant first voltage in column circuits of an imaging device. A second voltage line supplies a second voltage that is lower than the first voltage and is constant. A third voltage line supplies a constant third voltage. A fourth voltage line supplies a fourth voltage that is lower than the third voltage and is constant. The first voltage line is electrically connected to a drain of an NMOS transistor, and the third voltage line is electrically connected to a gate of the NMOS transistor. The second voltage line is electrically connected to a drain of a PMOS transistor, and the fourth voltage line is electrically connected to a gate of the PMOS transistor.

An imaging device includes: an imaging section in which a plurality of pixels each having a photoelectric conversion element are arranged in a matrix shape; a clock generator that generates a plurality of phase signals having different phases; a reference signal generator that generates a reference signal which increases or decreases with a lapse of time; a comparator that is disposed to correspond to each column of an array of the plurality of pixels, performs a comparing process of comparing a pixel signal output from each pixel with the reference signal, and outputs a first comparison result signal and a second comparison result signal indicating a result of the comparing process; a latch section that is disposed to correspond to the comparator and latches logic states of the plurality of phase signals; and a latch controller.

Imaging device for reducing deterioration of A/D conversion accuracy

An image sensor includes: photoelectric conversion elements configured to receive light and accumulate a charge corresponding to an amount of received light; an imaging signal generating unit that converts the charge accumulated in each photoelectric conversion element into a voltage to generate an imaging signal; and a reference signal generating unit that generates a reference signal having a fluctuation component with a same phase as the imaging signal. The imaging signal generating unit includes: a conversion circuit that converts the charge accumulated in each photoelectric conversion element into the imaging signal; a noise eliminating circuit that eliminates a noise component included in the imaging signal; and an output circuit that outputs the imaging signal from the conversion circuit. The reference signal generating unit includes a circuit having a same structure as that of at least one of the conversion circuit, the noise eliminating circuit, and the output circuit.

Image sensor, imaging device, endoscope, and endoscopic system

An image capturing device includes: an image capturing section having a plurality of pixels disposed in a matrix and configured to output a pixel signal via a first signal line connected to pixels arranged in a first direction among the plurality of pixels; a plurality of calculators including: a comparator configured to compare a magnitude of a first analog signal with a threshold value to generate a digital value according to a comparison result; an amplification section configured to amplify the first analog signal by multiplying the first analog signal by an amplification degree &#x3b2; (1&#x3c;&#x3b2;&#x3c;2) and output a second analog signal by executing computation according to the digital value; and a switching section configured to output one of the pixel signal and a &#x3b2; estimation signal as the first analog signal when a most significant bit of a first digital value sequence is computed.

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Tokyo, Japan

Yoshio Hagihara