Honda Giken Kogyo Kabushiki Kaisha

Other

Honda Giken Kabushiki Kaisha

Honda Giken Koygo Kabushiki Kaisha

Katsuhiko Takebe

Sukeyuki Shinotsuka

Satoshi Hiyama

Yasushi Okada

Masanobu Urabe

Mizuho Doi

Toshiaki Tanaka

Jiro Kurita

Hiroyasu Takehara

Hiroshi Abe

Jun Ashihara

Hiroyuki Ando

Nobuhiro Fueki

Makoto Furukawa

Atsushi Inaba

Shigeki Kato

Yamato Ishikawa

Tsuyoshi Hano

Katsuki Ichinose

Yuitsu Hayashikura

Toshio Imai

Disclosed is a light sensor circuit which works by producing in a photoelectric converting element a photo current proportional to a quantity of incident light falling thereon, converting the photo current into a voltage signal by using a threshold region characteristic of a transistor with a logarithmic output characteristic in a weak inverse state and producing a sensor output corresponding to the voltage signal. The light sensor circuit is provided with an initializing means for removing an electric charge remaining in a parasite capacitor of the photoelectric converting element before detecting light by the same element, thereby achieving a wide dynamic range and obtaining a sensor signal with no afterglow even if it works with a small quantity of incident light.

Light sensor circuit having source/drain voltage changing-over circuit to minimize afterglow

An output compensating device capable of optimally compensating output signals of an image sensor composed of a number of light-sensor circuits, each of which represents a unit pixel and is capable of producing in a photoelectric converting element a sensor current proportional to a quantity of light falling thereon, converting the current into a voltage signal by a MOS type transistor with a logarithmic output characteristic in a weak inverse state, initializing itself by removing a charge accumulated in a parasitic capacitor of the photoelectric converting element by changing a drain voltage of the transistor to a value lower than a normal value for a specified time and outputting a pixel signal having a logarithmic characteristic at a large quantity of the sensor current and a pixel signal having a non-logarithmic characteristic at a small quantity of the sensor current. This device has a means for compensating each pixel signal from the image sensor for an offset value and outputting a resulting signal if said signal has an output characteristic within a logarithmic response region or a non-logarithmic region depending on the output condition and, if not, further compensating the offset-compensated signal for its gain and outputting a resulting signal, thus ensuring the optimal compensation of each pixel signal of the image sensor in accordance with its output state.

Output-compensating device for image sensor

Disclosed is an image sensor consisting of light sensor circuits arranged to form an array of pixels, each of which produces in a photoelectric converting element a sensor current proportional to the quantity of light falling thereon and converts the sensor current into a voltage signal by a MOS type transistor with a logarithmic output characteristic in a weak inverse state, wherein a means for changing over a drain voltage of the transistor for each light sensor circuit to a value lower than a normal value for a specified time to remove a charge accumulated in a parasitic capacity of the photoelectric converting element to initialize the circuit before detecting a light signal. The image sensor can obtain a voltage signal corresponding to the quantity of incident light even if the sensor current was rapidly changed, thereby eliminating the possibility of occurrence of afterglow of each pixel even at a small quantity of incident light.

Image sensor with a voltage switching circuit for low afterglow

A photo-sensor circuit according to an embodiment of the present invention comprises a photo-detecting element (PD) for detecting a light signal and converting the same signal into an electric signal, a first MOS transistor (QT) for charging and discharging parasitic capacitance (C), a capacitor (C) for accumulating a terminal voltage of the photo-detecting element as a pixel signal, a second MOS transistor (Q) for transferring a parasitic capacitance charge from the photo-detecting element to the capacitor (C), a third MOS transistor (Q) for amplifying the terminal voltage of the capacitor and a fourth MOS transistor (Q) for selectively outputting an amplified pixel signal. In the above structure, the first MOS transistor and the second MOS transistor are turned ON for a certain period of time before accumulation of a pixel signal to equalize terminal voltages of the photo-detecting element and the capacitor by charging and discharging the parasitic capacitance of the photo-detecting element and the capacitor, the second MOS transistor is turned OFF and the capacitor is open after a certain period of time of accumulation of the pixel signal and then the fourth MOS transistor is switched ON. This photo-sensor circuit offers an advantageous feature of producing a pixel signal having high reproducibility.

Photo-sensor circuit with shutter function and operating method

In a solid-state image pick-up device having a photoelectrical conversion element cell array with a matrix arrangement of cells, between either a first or second signal line and a prescribed selection circuit that drives the signal line are provided a multiple signal line received light amount value storage means that includes a amount of received light detection means that separately reads out the amount of received light data for a plurality of photoelectrical conversion element cells connected to a plurality of selected signal lines in the other signal group, and a switching means that selectively transmits this detected amount of received light information to an output means.

Solid-state image pick-up device and drive method for same

A photosensor signal processing apparatus is used in combination with an image sensor comprised of a matrix of pixels or photosensors capable of producing an output as a linear function and a logarithmic function of incident illumination. The apparatus includes a correction data storage device which stores therein a set of data about the respective photosensors for the correction of individual outputs of the photosensors, and a correcting device for correcting the respective output values of the photosensors on the basis of the correction data. Thus, even when the individual outputs of the photosensors generate have different characteristics, the output characteristic variation between the photosensors are corrected such that the output characteristics of all the photosensors agree with a reference output characteristic. A fixed pattern noise resulting from the pixel-to-pixel output characteristic variation can be suppressed.

Photosensor signal processing apparatus

A solar cell comprising a substrate of insulating material, a bottom side electrode layer formed on one surface of the substrate, a semiconductor photoelectric conversion layer formed on the bottom side electrode layer, a transparent top side electrode layer formed on the semiconductor photoelectric conversion layer and a non-transparent electrode comprising a plurality of strips of non-transparent conductive layers disposed separately from each other on the top side transparent electrode layer. The solar cell further comprises an additional bottom side electrode layer formed on the opposite surface of the substrate and a plurality of conductive paths connecting the bottom side electrode layer to the additional bottom side electrode layer through holes or slits formed to penetrate the substrate.

Solar cell

An on-board vehicle display arrangement of a computer graphics device and two video cameras for generating left-viewpoint image and right-viewpoint image of vehicle guiding information, an image synthesizer for synthesizing the left-viewpoint image and right-viewpoint image by alternately arranging their elements by pixel, and a stereoscopic display for separately displaying a left-viewpoint image and a right-viewpoint image of the synthesized image, which images are provided inside the vehicle to display a stereoscopic image with outside information taken through the video cameras, vehicle travel guiding information generated by the computer graphics device according to navigation data, presumed travelling information generated by the computer graphics device according to a prospective running condition estimated from the results of detection of current driving conditions of the vehicle.

Information display device for vehicle

A photosensor circuit comprises a photoelectric transducer, an n-channel MOS transistor and an initial setting unit for precluding the occurrence of a residual image phenomenon. When an optical signal is generated by the photoelectric transducer, the initial setting unit sets the gate voltage of the n-channel MOS transistor at a high value for a predetermined time to lower the drain-source impedance of the n-channel MOS transistor to thereby control charge or discharge of a capacitor connected to a source terminal.

Photosensor circuit having an initial setting unit

A radar system is designed to allow switched use of a pulse radar mode for detecting a target at a long distance away and a phase-difference radar mode for detecting a target at a short distance away, whereby target detection can be performed from a very close range to a long range with high accuracy. Also, the pulse radar mode enables detection of a plurality of targets in different ranges.

Radar system

A plurality of radar devices are provided on and along the periphery of a vehicle for monitoring in different directions. While sequentially switching the radar device to be used for the monitoring operation in response to a transmission-enable signal, a processing device detects, for each direction, presence of and distance to an obstacle or object on the basis of a phase difference (time difference) between signals transmitted and received via the corresponding radar device. Thus, the processing device causes an image display device to show the detected conditions around the vehicle and also causes a sound synthesizer to output a sound message to call the vehicle operator's attention.

Vehicle-surroundings monitoring apparatus

This invention relates to a semiconductor sensor for detecting external physical forces, such as acceleration, contact pressures, air pressures, mechanical vibrations, etc. The semiconductor sensor according to this invention is characterized by the use of compound semiconductors of high piezoelectricity, such as GaAs, etc. Conventionally sensors of the cantilever type, diaphragm type, etc. are made of silicon. These prior art sensors have low detection sensitivity, and their characteristics tend to deteriorate. The sensor according to this invention is made of GaAs, which has high piezoelectricity and can retain good characteristics of the semiconductor even at high temperatures and includes a field-effect transistor formed on the GaAs for sensing a stress. The FET is driven by a constant current or a constant voltage so as to detect a change of an electrical characteristic (e.g., threshold characteristic) due to a stress. The structure of the sensor according to this invention enables the sizes of the sensors not only to be diminished but also to reduce the fabrication costs. When a stress is applied to the FET, the transconductance changes, and the temperature changes, consequently the I-V characteristic changes. An a.c. signal biased by a direct current is supplied to the gate of the FET, and a drain current is detected in an a.c. component and a d.c. component so as to detect a temperature concurrently with a detection of a stress.

Semiconductor sensor

A semiconductor sensor includes a field-effect transistor for detecting a physical quantity such as pressure, strain, acceleration or the like. The field-effect transistor is disposed on an elastically deformable portion of a cantilevered semiconductor substrate. A detected signal generator generates a signal representing a change in a drain current of the field-effect transistor in response to a stress which is applied to the field-effect transistor due to elastic deformation of the semiconductor substrate. The field-effect transistor may be supplied with a fixed gate bias voltage and an integrator may generate a signal representing an integral of the drain current for temperature compensation. Alternatively, an integrator may generate a signal representing an integral of the drain current, and a gate bias voltage may be applied to the field-effect transistor so that the signal generated by the integrator will be of a predetermined value for automatic temperature compensation. As a further alternative, a self-bias circuit may be connected between the field-effect transistor and the detected signal generator for applying a gate self-bias voltage to the field-effect transistor for automatic temperature compensation.

Growing community of inventors

Saitama, Japan

Katsuhiko Takebe