9515 results about "Photodiode" patented technology

When emitted light from LED 31 is incident on photodiodes 32 and 33 with luminance Pa and Pb, currents ia and ib are generated according to luminance Pa and Pb. When outside light is incident through the finger tissues on photodiodes 32 and 33 with luminance Pc, current ic is produced. The current i1 (=ia+ic) generated by photodiode 32, and the current i2 (=-ib-ic) generated by photodiode 33, are added at node X, and the current ic corresponding to outside light is thus cancelled. In addition, photodiodes 32 and 33 are disposed at different distances from LED 31. As a result, the current flowing to opamp 34 is current ia corresponding to luminance Pa because luminance Pb is extremely low. The opamp 34 then applies a current voltage conversion to generate pulse wave signal Vm.

A light-based touch screen, including a housing for a display screen, a plurality of infra-red light emitting diodes (LEDs), fastened on the housing, for generating light beams, at least one LED selector, fastened on the housing and connected with the plurality of LEDs, for controllably selecting and deselecting one or more of the plurality of LEDs, a plurality of photodiode (PD) receivers, fastened on the housing, for measuring light intensity, at least one PD selector, fastened on the housing and connected with the plurality of PD receivers, for controllably selecting and deselecting one or more of the plurality of PD receivers, an optical assembly, fastened on the housing, for projecting light beams emitted by the plurality of LEDs in substantially parallel planes over the housing, and a controller, fastened on the housing and coupled with the plurality of PD receivers, (i) for controlling the at least one LED selector, (ii) for controlling the at least one PD selector, and (iii) for determining therefrom position and velocity of an object crossing at least one of the substantially parallel planes, based on output currents of the plurality of PD receivers.

Illumination devices and related systems and methods are closed that can be used for LCD (Liquid Crystal Display) backlights, LED lamps, or other applications. The illumination devices can include a photo detector, such as a photodiode or an LED or other light detecting device, and one or more LEDs of different colors. A related method can be implemented using these illumination devices to maintain precise color produced by the blended emissions from such LEDs. One application for the illumination devices is backlighting for FSC (Field Sequential Color) LCDs (Liquid Crystal Displays). FSC LCDs temporally mix the colors in an image by sequentially loading the red, green, and blue pixel data of an image in the panel and flashing the different colors of an RGB backlight. Precise and uniform color temperature across such a display can be advantageously maintained by continually monitoring ratios of photodiode currents induced by the different colored LEDs in each illumination device as each color is flashed.

A microcrystalline germanium image sensor array. The array includes a number of pixel circuits fabricated in or on a substrate. Each pixel circuit comprises a charge collecting electrode for collecting electrical charges and a readout means for reading out the charges collected by the charge collecting electrode. A photodiode layer of charge generating material located above the pixel circuits convert electromagnetic radiation into electrical charges. This photodiode layer includes microcrystalline germanium and defines at least an n-layer, and i-layer and a p-layer. The sensor array also includes and a surface electrode in the form of a grid or thin transparent layer located above the layer of charge generating material. The sensor is especially useful for imaging in visible and near infrared spectral regions of the electromagnetic spectrum and provides imaging with starlight illumination.

An imaging device includes an image sensor chip and a package for containing the image sensor chip. Formed in the package is a vent hole that is connected to an air pump. In a light receiving area of the image sensor chip, there are photodiodes and microlenses above them. The microlenses are made of a gel-like transparent material. When the internal air pressure of the package is changed by the air pump, each microlens transforms in response to the change of the internal air pressure, and thereby changes the surface curvature thereof.

The present invention provides a technique for continuous measurement of blood pressure based on pulse transit time and which does not require any external calibration. This technique, referred to herein as the ‘Composite Method’, is carried out with a body-worn monitor that measures blood pressure and other vital signs, and wirelessly transmits them to a remote monitor. A network of body-worn sensors, typically placed on the patient's right arm and chest, connect to the body-worn monitor and measure time-dependent ECG, PPG, accelerometer, and pressure waveforms. The disposable sensors can include a cuff that features an inflatable bladder coupled to a pressure sensor, three or more electrical sensors (e.g. electrodes), three or more accelerometers, a temperature sensor, and an optical sensor (e.g., a light source and photodiode) attached to the patient's thumb.

A non-invasive near infrared spectrophotometric monitoring transducer assembly includes a housing member, which is adhered directly on a patient's skin. The housing member contains a prism coupled to a flexible and lightweight single core optical light guide, which provides a means of transferring narrow spectral bandwidth light from multiple distant laser diodes of different wavelengths by use of a multi-fiber optic light combining assembly. Different wavelengths are needed to monitor the level of blood oxygenation in the patient. The assembly also contains a planar light guide mounted on the prism located in the housing member, which light guide contacts the patient's skin when the housing member is adhered to the patient's skin. The light guide controls the spacing between the prism and the patient's skin, and therefore controls the intensity of the area on the patient's skin which is illuminated by the laser light. The housing member contains a photodiode assembly, which detects the infrared light at a second location on the skin to determine light absorption. The photodiode assembly is preferably shielded from ambient electromagnetic interference (EMI) by an optically transparent EMI attenuating window. This rigid window placed over the photodiode also provides a planar interface between the assembly and the skin, improving optical coupling and stability as well as reducing the capacitive coupling between skin and the photodiode resulting in further EMI attenuation. The housing may be associated with a disposable sterile hydrogel coated adhesive envelope, or pad, which when applied to the patient's skin will adhere the housing to the patient's skin. The transducer assembly will thus be reusable, and skin-contacting part of the device, i.e., the envelope or pad can be discarded after a single use. The assembly also includes a laser safety interlock means, which is operable to turn off the laser light output in the event that the assembly accidentally becomes detached from the patient's skin.

A wireless X-ray detector for a digital radiography system with remote detection of impinging radiation from the system X-ray source onto a sensor panel having amorphous or crystalline silicon photodiodes or metal insulated semiconductor (MIS) sensors. Changes in current in the photodiode bias supply circuit is sensed to generate a signal indicating presence of radiation. Improved detection of X-ray cessation is achieved either by leaving at least one line of sensors connected between the bias supply circuit to a virtual ground during charge accumulation or by using an X-ray presence detector circuit that increases the sensitivity of the detector circuit to bias circuit current changes occurring after onset of the radiation.

With small dimensional optics, small photovoltaic cells have heat distribution surfaces, very high concentrations and subsequently high utilization of the semiconductors can be achieved. Discrete photodiodes can be formed as spherical and other geometric shaped, cells with high performance characteristics, precision dimensions, and low cost. This invention positions discrete photovoltaic cells by using their geometric shape, elastic electrical mounts, couples them to small optical concentrator systems of refractory and or reflective optics and makes electrical network connections to those photodiodes, reliably, adjusting for thermal expansion, and at low cost to form low cost and reliable electrical power arrays. The electrical connectors and network can form part of the reflective optics and heat removal system. The electrical interconnection system can also form a reliable network that is self-correcting and tolerant of point failures.

A single integrated-circuit color camera chip is color sensitive by grouping closely-adjoining light-detecting cells in a photodiode array into triplets. Each pixel of the sensor includes both a read transistor and a write transistor. Each cells in the triplet is similar, but each cell is associated with a color filter of a different color, with red, green or blue cells in an R-G-B system. The proximity and small size of the cells in a triplet allows accurate color differentiation each pixel. Color information is adjusted on-chip for color, brightness and contrast before being sent to an external read device or display device. The color filter is a series of passive layers formed on the integrated circuit surface permitting the selective transmission of light or electromagnetic radiation of certain frequency ranges. The filter may be coated onto a semiconductor wafer after the latter has undergone conventional MOS process steps.

A display device includes a pixel which includes a first photosensor portion having a first photodiode for detecting visible light, which is provided together with a display element portion; and a pixel which includes a second photosensor portion having a second photodiode for detecting infrared rays, which is provided together with another display element portion. The second photosensor portion detects infrared rays included in external light, and selects an imaging element and adjusts sensitivity in accordance with the amount of infrared rays detected by the second photosensor portion.