1249 results about "Large dynamic range" patented technology

Electronic self-test and/or self-diagnostic systems particularly useful with emergency lighting fixtures, including exit signage having light emitting diodes as light sources and unit emergency fixtures powered with lead-acid batteries, the systems perform testing and diagnostic functions on the circuitry, power supply, charger and lamping of such fixtures either by manual or automatic initiation. Testing functions are provided through use of a programmable microprocessor, the diagnostic circuitry not only monitoring operation of charger/transfer circuitry but also controlling the charger/transfer circuitry to enable alternate strategies for alleviation of a given failure. In emergency mode of a light emitting diode exit sign, a microprocessor-controlled two-stage inverter is employed not only to power the LED light source, but also to efficiently power the microprocessor. Power to the microprocessor is controlled by the microprocessor itself and can therefore be discontinued after appropriate operation until mains power is restored, thereby effectively reducing power consumption to zero. System operation can be flexibly configured through use of a two-wire serial link between modular elements of the system. Incandescent emergency unit fixtures due to high drain rates and output loads require emergency mode operation through use of lead-acid batteries, thereby requiring voltage controlled charging and relay transfer, the self-test and/or self-diagnostic circuitry of the invention used with emergency unit fixtures thus differing in various respects from the circuitry employed for the LED exit signage fixtures and primarily in the need to measure both charge and discharge currents, the circuitry having a larger dynamic range in addition to a capability of measuring both positive and negative currents.

A method for displaying an image includes receiving an image having a first luminance dynamic range and modifying the image to a second luminance dynamic range free from being based upon other images, where the second dynamic range is greater than the first dynamic range. The modified image is displayed on a display.

Example embodiments of a large dynamic range sequential wavefront sensor for vision correction or assessment procedures are disclosed. An example embodiment optically relays a wavefront from an eye pupil or corneal plane to a wavefront sampling plane in such a manner that somewhere in the relaying process, the wavefront beam from the eye within a large eye diopter range is made to reside within a desired physical dimension over a certain axial distance range in a wavefront image space and/or a Fourier transform space. As a result, a wavefront beam shifting device can be disposed there to fully intercept and hence shift the whole beam to transversely shift the relayed wavefront.

An imaging apparatus appropriately captures a large dynamic range image of even a scene including a backlit person with a blue sky background in a manner that the person's face has an appropriate luminance level without saturating the background sky. In the imaging apparatus, an imaging unit obtains analogue image signals through exposure control that prevents a highlight from being saturated, an A/D converter converts the analogue image signals to digital image signals, and a signal processing unit linearly increases the dynamic range of the digital image signals. The image signals with the increased dynamic range are nonlinearly compressed to have a dynamic range of 100% or less through nonlinear dynamic range compression that intensively compresses a highlight portion. The imaging apparatus with this structure first increases the dynamic range of an image and efficiently compresses the increased large dynamic range of the image.

An image detecting device has a large dynamic range that deals with a plurality of image detecting modes. The image detecting device is composed of pixels e (i, j) arranged in a matrix array. Each pixel has a photoelectric element. In each pixel, a capacitor 102 and a protecting diode 103 are disposed. The capacitor 102 stores electric charge corresponding to the intensity of penetrated light to the relevant pixel. The protecting diode limits the capacitance. A bias voltage is supplied to the protecting diode 103 through a bias line Bias. The bias voltage is adjusted by a bias voltage controlling system 133 corresponding to the frame rate. Thus, the influence of a leak current in the off-state of the protecting diode 103 can be alleviated against electric charge stored in the capacitor 102. Consequently, an image with a high S/N ratio can be obtained regardless of the frame rate.

The invention relates to the field of mobile communication terminals, and discloses a mobile phone camera-based latitude realization method and a mobile phone. In the mobile phone camera-based latitude realization method and the mobile phone provided by the invention, two cameras are adopted, one camera performs photometry and simultaneously changes the exposure of the second camera, the two cameras simultaneously perform shooting, and shot images are synthesized in a baseband chip by a software synthesis algorithm to obtain a photo with a large dynamic range. Therefore, the mobile phone has a new latitude shooting function and a better shooting effect, and the shot photos are clearer.

The invention discloses an infared nonuniformity correction method for removing temperature shift. In the method, the correction gain and offset of a two-point correction algorithm are solved first, and then correction offset of a one-point correction algorithm is solved; and image data during the solving of offset parameters of the one-point correction algorithm is from the data solved after two-point correction. The method has the advantages of low cost, wide correction dynamic range, good effect, and simple principle and the characteristics of high efficiency, accuracy and the like, can be easily implemented in the aspect of hardware, and is suitable to be used in a focal plane imaging system. The technology is technical improvement on uniformity of an infared focal plane and contributes to promoting the good performance of an infared focal plane system.

A new measurement system, with two receiver channels per measurement port, has been developed that provides absolute magnitude and absolute phase relationship measurements over wide bandwidths. Gain ranging is used at RF to provide optimum noise performance and a swept YIG preselector filter is used to avoid spurious signals. A new absolute vector error correction method is used to calibrate the measurement system in order to allow for absolute vector measurements, and it also removes the time-varying responses caused by the swept YIG preselector filters. A quasi-reciprocal mixer with a characterized non-reciprocal ratio is used to provide the absolute calibration standard. The two receiver channels can be adapted to a wide variety of applications, including wide bandwidth vector signal analyzer measurements, mixer measurements, and harmonic measurements. The two-channels can also be used as an absolute calibrated transmitter/reflectometer.

Time-of-flight mass spectrometer instruments are disclosed for monitoring fast processes with large dynamic range using a multi-threshold TDC data acquisition method or a threshold ADC data acquisition method. Embodiments using a combination of both methods are also disclosed.

The invention discloses a microwave photonic transceiver based on coherent optical frequency combs. A signal optical frequency comb and a local oscillator optical frequency comb which are coherent are generated through a seed light source module and are each divided into two paths through two beam splitters; for a transmitting module, one path of the signal optical frequency comb is taken and each comb tooth is separated through a de-multiplexing module, a to-be-transmitted intermediate frequency signal is loaded through electro-optical modulation, the modulated signal optical frequency comb and one path of the local oscillator optical frequency comb are combined, and a high-frequency transmitting signal is obtained through photo-electric detection; for a receiving module, the other path of the signal optical frequency comb directly loads a receiving signal through an electro-optical modulator and sends the receiving signal to a signal light input end of an optical mixer, the other path of the local oscillator optical frequency comb is input into a local oscillator light input end of the same optical mixer, and two paths of orthogonal output light signals of the optical mixer are taken to carry out channel cut and coherent detection respectively. The microwave photonic transceiver disclosed by the invention has large real-time processing bandwidth and large dynamic range, and the system consumption is effectively reduced.

The present invention relates to a semiconductor photosensitive unit and a semiconductor photosensitive unit array thereof, including a floating gate transistor, a gating MOS transistor and a photodiode that are disposed on a semiconductor substrate. An anode or a cathode of the photodiode is connected to a floating gate of the floating gate transistor through the gating MOS transistor, and the corresponding cathode or anode of the photodiode is connected to a drain of the floating gate transistor or connected to an external electrode. After the gating MOS transistor is switched on, the floating gate is charged or discharged through the photodiode; and after the gating MOS transistor is switched off, charges are stored in the floating gate of the floating gate transistor. Advantages like a small unit area, low surface noise, long charge storage time of the floating gate, and large dynamic range of an operating voltage are achieved.

The invention provides a high-precision and high-integrality time-digital converter based on an FPGA (Field Programmable Gate Array), and an implementation method. The time-digital converter comprises a fine time measuring unit, wherein the fine time measuring unit consists of a time alternate sampling unit, a multi-stage sampling data buffering unit and a snapshot and encoding unit. The invention aims to provide the high-integrality precision time-digital converter based on an FPGA. Innovation points lie in that: a fine time measuring part adopts a technology of a latch snapshot and rapid encoding combined architecture based on phase splitting clock alternate sampling, multi-stage sampling data caching and cached multi-stage sampling data. The high-precision and high-integrality time-digital converter has the characteristics of simple structure, design flexibility, high portability, short measuring dead time, large dynamic range, low cost, flexible interface and the like, and can be applied to the fields of aerospace, space research, communication, biomedicine, earth dynamics, relativity research and the like.

A general method is provided for electronically reconfiguring the internal structure of a solid to allow precision control of the propagation of wave energy. The method allows digital or analog control of wave energy, such as but not limited to visible light, while maintaining low losses, a multi-octave bandwidth, polarization independence, large area and a large dynamic range in power handling. Embodiments of the technique are provided for large-angle beam steering, lenses and other devices to control wave energy.

The invention discloses a long-distance distributed optical fiber vibration sensing system and a method thereof. The system comprises an induction system for inducting outside vibration events and a detecting and controlling system for detecting and controlling vibration signals; the induction system is connected with the detecting and controlling system. The induction system comprises a light source, a pulse modulator, an optical fiber circulator, a first optical fiber amplifier, and a light switch of a first optical fiber filter. The detecting and controlling system comprises a plurality of optical-electrical converters and a system control unit; the system control unit collects output light of the converters, analyzing the collected signals and judges whether the alarm is needed according to the analysis result. The invention adopts the optical switch technology to adopt time-division processing on backward Rayleigh scattering light which is reflected back, the dynamic range of the system is large, and the sensible distance can be tens of kilometers as high as possible, even hundreds of kilometers; and the invention adopts phase detecting technology and optical time domain reflection technology and can greatly improve detecting sensibility of the system and positioning precision.

Methods and apparatuses for the determination of an attribute of the tissue of an individual use non-invasive Raman spectroscopy. For example, the alcohol concentration in the blood or tissue of an individual can be determined non-invasively. A portion of the tissue is illuminated with light, the light propagates into the tissue where it is Raman scattered within the tissue. The Raman scattered light is then detected and can be combined with a model relating Raman spectra to alcohol concentration in order to determine the alcohol concentration in the blood or tissue of the individual. Correction techniques can be used to reduce determination errors due to detection of light other than that from Raman scattering from the alcohol in the tissue. Other biologic information can be used in combination with the Raman spectral properties to aid in the determination of alcohol concentration, for example age of the individual, height of the individual, weight of the individual, medical history of the individual and his/her family, ethnicity, skin melanin content, or a combination thereof. The method and apparatus can be highly optimized to provide reproducible and, preferably, uniform radiance of the tissue, low tissue sampling error, depth targeting of the tissue layers or sample locations that contain the attribute of interest, efficient collection of Raman spectra from the tissue, high optical throughput, high photometric accuracy, large dynamic range, excellent thermal stability, effective calibration maintenance, effective calibration transfer, built-in quality control, and ease-of-use.

The invention provides a high-speed large dynamical range digital automatic gain control circuit, comprising a variable gain amplifier, a high-speed peak retainer, a lowpass filter, an A/D converter and a digital signal range judging and gain controller; the gain of an externally input pulse voltage signal is controlled by the variable gain amplifier and sent to the high-speed peak retainer which widens the peak of the received signal and sends the signal to the lowpass filter so as to carry out analog filtration; the output signal of the lowpass filter is converted by the A/D converter and then sent to the digital signal range judging and gain controller which compares the received digital signal with a valve value arranged in advance and controls the amplification multiple of the variable gain controller according to the comparison result. The AGC circuit has simple structure and high control precision.

A pixel for the detection of electromagnetic radiation or impinging high energy particles, in particular for detecting X-ray photons, comprises a radiation receptor for converting the electromagnetic radiation or impinging high energy particles into a radiation signal, a converter for converting the radiation signal into a pulse train, and an analog accumulator for accumulating the pulses of a pulse train to an analog signal for readout. The analog accumulator is adapted such that the analog signal is non-linearly proportional to the pulse count. Such non-linear analog accumulator has the advantage of an large dynamic range.

The invention discloses a relay transmitting system used for an unmanned helicopter, which rises the height of the unmanned helicopter to promote the transmission quality of signals in a spatial channel, and can transmit the relay with a weak signal even in the distance, thus increasing the communication distance; the invention is characterized by high sensitivity, wide dynamic range, broad transmitting band and good anti-interference performance. The invention comprises two main parts of an airborne part and a ground part, wherein, the airborne part is carried with a relay transmitting subsystem and consists of four modules of an airborne receiving antenna, an airborne relay transmitting module, a broad band filter and an airborne transmitting antenna; and the ground part comprises a ground receiving subsystem including three modules of a ground receiving antenna, a vehicle low noise amplifier and a ground receiving module. The system of the invention is simple, high-efficient and reliable and has low cost. By combining with the flexibility and mobility of the unmanned helicopter, the system of the invention can be applied in the fields of television and broadcasting, etc.

Radio frequency transmission systems often suffer from the problem of co-site interference, where the frequency band of a strong radio transmitter overlaps with the frequency band of a co-located and/or remote radio receiver, such that the transmitter interferes with the ability of the receiver to detect a weak signal of interest. There is a need for a device that can process both the transmitted radio signal and the received radio signal to eliminate such interference. Previous attempts to solve this problem have been unable to cancel in-band interference in excess of 20 to 40 dB stronger than the signal of interest over a broad bandwidth, with large dynamic range, and with a high degree of linearity. Disclosed is a robust system and method for cancelling broadband in-band RF interference that operates in a dynamically changing multipath environment.

The invention relates to a programmable beam forming network on the basis of an optical wavelength division multiplexing technology, which structurally comprises a wavelength division multiplexer, an electrooptic modulator, a 1*2 optical switch, a 2*2 optical switch, an optical amplifier, a circulator, a Faraday rotatormirror and an optical fiber true-time delay line. According to the invention, coherent microwave carrier signals with different phase delays can be generated, so that a function of an electric phase shifter in a conventional electric-control phase-control array radar is replaced and an aperture effect in the conventional phase-control array radar is greatly eliminated; and the programmable beam forming network has the advantages of ultra wide band, large dynamic range, programmable control and the like.