Abstract: Disclosed are improved LiDAR systems and methods that achieve an improved signal-to-noise by interrogating a sub-region of a scene with an optical signal. An instantaneous field-of-view (FOV) of each detector pixel is narrowed along a first direction to reduce detection of solar-generated photons. Instantaneous FOVs of the pixels are compressed along the first direction to provide a composite FOV that is narrower than a total FOV. To sample the total FOV of a scene, the optical signal and composite FOV of the receiver are scanned across the scene along the first direction.

Abstract: An apparatus for determining a distance to a target area, including at least one imaging system configured to provide at least two images of a target area, the images being associated with different imaging axes for forming a stereo image of the target area. The apparatus also includes a Lidar system including at least one laser configured to direct an optical beam to the target area and an optical detection system configured to receive a portion of the optical beam from the target area and establish a distance to the target area based on the received portion.

Abstract: A sensor such as a presence sensor for use in a lighting system or other system that adapts to information from a plurality of active presence sensors. If transmissions from the active sensors are uncoordinated, the overall detection performance may be adversely impacted (e.g. due to potential cross-interference), which may make sensing over the detection coverage area defined by a single presence sensor (or the like) become unreliable. The disclosure presents protocols for coordinating transmissions in active sensing systems. The invention may be applied to various active modalities (e.g. ultrasound, RF), for example that find applications in indoor and outdoor lighting controls.

Abstract: A radar apparatus includes: a transmission processor, which, in operation, transmits first wave signals from inside of the bumper toward outside, the transmission processor being provided inside of the bumper; a reception processor, which, in operation, receives an object-reflected wave signal that is a reflection of the first wave signals by a target in an area around the vehicle, a bumper-reflected wave signal that is a reflection of the first wave signals by the bumper, and a transmission and reception leak signal of the first wave signals and detects the target through the object-reflected wave signal; and a bumper determiner, which, in operation, detects a first reception level of a second wave signal including the bumper-reflected wave signal and the transmission and reception leak signal, compares the first reception level with a threshold, and determines the presence of a bad bumper state in a case where the first reception level is higher than the threshold.

Abstract: Systems and methods for using velocity measurements to adjust Doppler filter bandwidth are provided herein. In certain embodiments, a method for adjusting bandwidth for at least one Doppler filter in a Doppler beam sharpened radar altimeter comprises receiving a velocity measurement; adjusting the bandwidth of the at least one Doppler filter based on the velocity measurement; and transmitting a radar beam, wherein the radar beam is aimed toward a surface. The method further comprises receiving at least one reflected signal, wherein the at least one reflected signal is a reflection of the radar beam being reflected off of at least one portion of the surface; and filtering the at least one reflected signal with the at least one Doppler filter to form at least one Doppler beam.

Abstract: A method operates a counter device for a fluid which can be connected via a connecting device to a meter point having at least one line through which the fluid flows. A control device is configured when connected via at least one operating parameter specific for the meter point and/or a meter point environment. When the counter device is taken into operation, the operating parameters are called up by a communication device on the counter device side communicating wirelessly by radio via a communication link with a passive communication device on the meter point side. The operating parameters are stored in a storage device of the passive communication device.

Abstract: Methods for radar altimeter integrity monitoring are provided.

Abstract: A method for automatic target recognition in synthetic aperture radar (SAR) data, comprising: capturing a real SAR image of a potential target at a real aspect angle and a real grazing angle; generating a synthetic SAR image of the potential target by inputting, from a potential target database, at least one three-dimensional potential target model at the real aspect angle and the real grazing angle into a SAR regression renderer; and, classifying the potential target with a target label by comparing at least a portion of the synthetic SAR image with a corresponding portion of the real SAR image using a processor.

Abstract: There is provided a radar device. A detecting unit is configured to detect a lateral location of a target relative to a vehicle equipped with the radar device, on the basis of reflected waves from the target. A selecting unit is configured to select a predetermined number of detection values from a detection value history including detection values of the lateral location detected by the detecting unit in chronological order. The predetermined number depends on a turning radius of the vehicle. A determining unit is configured to determine a definite value of the lateral location on the basis of the detection values selected by the selecting unit.

Abstract: A method for locating an object underwater may involve using a sound transmitter to transmit a sound pulse. The sound pulse may be reflected by the object to be located and then received by a sound receiver. The sound receiver may be spatially distant from the sound transmitter, meaning that the sound receiver is spaced apart from the sound transmitter by an amount that is of a similar order of magnitude as a distance between the sound transmitter and the object or between the sound transmitter and the seafloor. The sound pulse may contain encoded information relating to a time of transmission of the sound pulse and a transmission position of the sound transmitter. The encoded information may then be decoded by the sound receiver to determine the position of the object.

Abstract: A device for sensing a passing athlete. The device has one or more signal sources for irradiating distinct segments of space about the device. One or more sensors are associated with the segments of space, and are arranged to sense a signal reflected off an athlete. The sensor(s) output a sensor signal indicating whether an athlete is present in each segment based on whether a reflected signal is detected from that segment. The segments are angularly positioned about the device so that the sensor(s) signals may be assessed to determine angular progression of the athlete relative to the device.

Abstract: A system for deploying sonar for surveying in deep water includes a submerged movable platform deployed in the deep water at a depth below a thermocline and surface wave action, a propulsion mechanism for moving the platform through the water in a controlled manner, and a multibeam echosounder attached to the platform, wherein the echosounder includes a Mills Cross transmitter and receiver array. A method for deploying sonar for surveying in deep water comprises deploying a submerged movable platform in the deep water at a depth below a thermocline and surface wave action, employing a propulsion mechanism for moving the platform through the water in a controlled manner, and employing a multibeam echosounder attached to the platform, wherein the multibeam echosounder comprises a Mills Cross transmitter and receiver array.

Abstract: Optical systems and methods for object detection and location. One example of an optical system includes a laser radar optical source positioned to emit a pulsed laser beam, a non-mechanical beamsteering device positioned to scan the beam in a linear scan over a first area of a scene, a laser radar detector positioned to receive and integrate a reflection of the beam, a read-out integrated circuit (ROIC) configured to provide a first read-out signal based on the integrated reflection, and a controller configured to receive the first read-out signal, determine a range to the first area based on a time of flight of the pulsed laser beam, and identify a presence of an object within the scene based on a signal level of the first read-out signal, the first signal level corresponding to a reflectivity of a portion of the object within the first area of the scene.

Abstract: An electronic device includes: a memory; a first infrared-ray emitter that emits a first infrared ray; a second infrared-ray emitter that emits a second infrared ray whose wavelength is partially overlapped with a wavelength of the first infrared ray; and a processor that is connected to the memory, the first infrared-ray emitter, and the second infrared-ray emitter. The processor is configured to determine whether an object is located in proximity to a device concerned during a proximity determination period based on a reflected light of the first infrared ray emitted, generate a capture image based on a reflected light of the second infrared ray emitted, conduct biometric authentication during an authentication period by using the capture image generated, and during the proximity determination period, stop emission of the second infrared ray or decrease an emission intensity of the second infrared ray from a reference level.

Abstract: Disclosed herein is an electronic device having a substrate, and an integrated circuit disposed within the substrate and having a top surface. The integrated circuit may be a laser emitting integrated circuit or a reflected light detector. A first interconnect layer is formed on the top surface of the substrate. A first optically transparent layer is formed on the top surface of the substrate and covering the top surface of the integrated circuit. A second interconnect layer is formed on a top surface of the first optically transparent layer. The second interconnect layer is patterned so as to not obstruct light traveling to or from the top surface of the integrated circuit through the first optically transparent layer.

Abstract: A multi-wavelength array lidar system and a method of designing an array lidar system include arranging a plurality of lasers in an array to transmit a respective plurality of beams, arranging a lens to disperse the plurality of beams at a respective plurality of angles, and arranging a band pass filter to filter a plurality of reflections received at a respective plurality of incident angles resulting from the plurality of beams transmitted by the plurality of lasers at a respective plurality of transmit angles. Selecting a transmit wavelength of each of the plurality of beams is based on the respective plurality of transmit angles to ensure that a receive wavelength of each of the plurality of reflections is within a narrower range than a range of the transmit wavelengths.

Abstract: Methods and systems for performing three dimensional LIDAR measurements with multiple illumination beams scanned over a three dimensional environment are described herein. In one aspect, illumination light from each LIDAR measurement channel is emitted to the surrounding environment in a different direction by a beam scanning device. The beam scanning device also directs each amount of return measurement light onto a corresponding photodetector. In some embodiments, a beam scanning device includes a scanning mirror rotated in an oscillatory manner about an axis of rotation by an actuator in accordance with command signals generated by a master controller. In some embodiments, the light source and photodetector associated with each LIDAR measurement channel are moved in two dimensions relative to beam shaping optics employed to collimate light emitted from the light source. The relative motion causes the illumination beams to sweep over a range of the three dimensional environment under measurement.

Abstract: A time synchronization method that is capable of selecting whether synchronization, by a timepiece unit that generates a time signal synchronized with a standard time and outputs it to an exterior, with the time is performed by time information obtained by receiving a radio wave including information relating to the time, or is performed by means of a holdover performed using a clock signal from an internal or external clock source. A schedule having a first time period in which the above-mentioned time information is used, and a second time period by means of the holdover is determined according to temporal reception characteristics of the radio wave at a reception location of the radio wave, and according to the schedule, supplying the timepiece unit with the time information or supplying the timepiece unit with the clock signal from the internal or external clock source.

Abstract: A method, system and apparatus are claimed for receiving, blindly despreading, and determining geo-observables, of true civil Global Navigation Satellite Systems (GNSS) navigation signals generated by any of the set of satellite vehicles and ground beacons, amongst false echoes and malicious GNSS signals from spoofers and repeaters; for identifying malicious GNSS signals, and preventing those signals from corrupting or capturing Pointing, Navigation, and Timing tracking operations; and for geolocating malicious GNSS signals. The invention also provides time-to-first-fix over much smaller time intervals than existing GNSS methods and can operate both in the presence of signals with much wider disparity in received power than existing techniques, and in the presence of arbitrary multipath.

Abstract: A positioning system having an onboard positioning device and a roadside device is provided. The onboard positioning device receives a plurality of first positioning signals and records a positioning moving locus of a vehicle according to the first positioning signals. The roadside device detects a real moving locus of the vehicle. The onboard positioning device obtains the real moving locus from the roadside device, and calculates a positioning calibration value according to coordinates of the positioning moving locus and coordinates of the real moving locus. Furthermore, the onboard positioning device receives a plurality of second positioning signals and calculates and outputs a plurality of calibrated positioning coordinates according to the second positioning signals and the positioning calibration value.

Abstract: A wireless device includes a wireless antenna, a power supply, and a movement sensor, the wireless device configured for triggered sending of wireless signals to one or more receiving devices to determine location of the wireless device, and the wireless device comprising a connection for external power, a connection for programming, and a connection for self-charging.

Abstract: A small-sized state calculating device which may acquire a highly-precise state calculation value is provided. The state calculating device may include antennas, receiving parts, a phase difference calculating part and an operation part. The receiving parts may calculate carrier phase measurements PYA, PYB and PYC of GNSS signals received by the antennas, respectively. The phase difference calculating part may set the antennas to be switched between a master antenna and a slave antenna, and calculate the plurality of inter-antenna phase differences ??AB, ??BC and ??CA, for every combination of the master antenna and the slave antenna, using the carrier phase measurements PYA, PYB and PYC. The operation part may calculate an attitude angle AT using the plurality of inter-antenna phase differences ??AB, ??BC and ??CA.

Abstract: A radiation dosimetry gel is excellent in heat resistance, and a radiation dosimeter includes the radiation dosimetry gel as a material for measuring a radiation dose. A radiation dosimetry gel includes a water-soluble organic polymer (A) having an organic acid salt structure or an organic acid anion structure, a silicate (B), and a dispersant (C) for the silicate, and a radiation dosimeter includes the radiation dosimetry gel as a material for measuring a radiation dose.

Abstract: A method for photon counting for pixels in a pixelated detector is disclosed, wherein for each of the pixels, one or more neighbouring pixels are defined. The method comprises receiving a charge in one or more of the pixels and comparing for each of the pixels the charge with a trigger threshold. If the charge in a pixel is above the trigger threshold, the charge is registered in the pixel after a registration delay, wherein the registration delay is dependent on the level of the charge received in the pixel in such a way that a registration delay decreases with increasing charge. A counter for a pixel is incremented when the charge is registered and an increment of a counter of the neighbouring pixels is inhibited. Pixelated semiconductor detectors are also disclosed.

Abstract: An ultra-thin radiation detector includes a radiation detector gas chamber having at least one ultra-thin chamber window and an ultra-thin first substrate contained within the gas chamber. The detector further includes a second substrate generally parallel to and coupled to the first substrate and defining a gas gap between the first substrate and the second substrate. The detector further includes a discharge gas between the substrates and contained within the gas chamber, where the discharge gas is free to circulate within the gas chamber and between the first and second substrates at a given gas pressure. The detector further includes a first electrode coupled to one of the substrates and a second electrode electrically coupled to the first electrode. The detector further includes a first discharge event detector coupled to at least one of the electrodes for detecting a gas discharge counting event in the electrode.

Abstract: An X-ray detector and an X-ray image system using the same are disclosed. The X-ray image system comprises an X-ray generator irradiating X-rays to an object to be photographed; an X-ray detector including a first photoelectric converter receiving X-rays transmitted the object and converting the X-rays in to a first electric signal and a second photoelectric converter converting the X-rays in to a second electric signal; a first image processor processing a first image of the object on the basis of the first electric signal of the X-ray detector; a second image processor processing a second image of the object on the basis of the second electric signal of the X-ray detector; a display module displaying the first and second processed images of the object; and a controller controlling the X-ray generator, the X-ray detector, the first and second image processors and the display module.

Abstract: A method is provided including, acquiring detection events with a radiation detector including a semiconductor plate and configured to produce electrical signals in response to absorption of ionizing radiation in the semiconductor plate, wherein electrons and holes are generated responsive to absorption of the ionizing radiation. The semiconductor plate includes a first surface opposed to a second surface, with sidewalls interposed between the first surface and the second surface. A cathode electrode is disposed on the first surface and pixelated anode electrodes are disposed on the second surface. The method also includes optically coupling infrared (IR) radiation into a first portion of at least one of the sidewalls of the semiconductor plate of the radiation detector, and not coupling IR radiation into a second portion of the at least one of the sidewalk.

Abstract: A radiation imaging apparatus has a sensor that converts irradiated radiation into a charge in accordance with a radiation dose, a switching power supply for supplying power to at least the sensor, and a readout unit that reads out a signal corresponding to the charge from the sensor. The radiation imaging apparatus synchronizes the imaging synchronization signal and a control clock for a switching operation of the switching power supply, causes a readout of signal from the sensor by the readout unit to be executed, and adjusts the phase of the control clock in each cycle of the imaging synchronization signal so that a timing of the imaging synchronization signal that occurs cyclically is at the same phase of the control clock.

Abstract: A method for calibrating an ionising radiation detector, with the aim of determining a correction factor in order to establish an amplitude-energy correspondence. The invention first relates to a method for calibrating a device for detecting ionising radiation, the detector comprising a semiconductor or scintillator detection material capable of generating a signal S of amplitude A upon interaction between ionising radiation and the detection material, the method including the determination of a weighting factor at the amplitude A.

Abstract: A seismic source system uses at least one seismic source, a screw in piling ground anchor installed into the earth/ground and means of coupling the energy from the seismic source to the screw in piling ground anchor.

Abstract: A measure of structural growth of subsurface geological formations layers or intervals is obtained to investigate and analyze layer structure development history. The measure or indication can be considered a structural growth index (SGI) and is used to evaluate for possible presence of hydrocarbons in the layers or strata in a structure of concern. The structural growth measure or index for a given geologic interval of interest is defined as the ratio of the layer thickness difference measured at two selected locations, one at a structural high and the other at a structural low of layer or interval, over the larger number of the paired-thickness measurements. The structural growth measure is determined for a series of sequentially layered geologic formations of interest and displays of determined measures are formed as functions of geologic time for the formations. Based on the structural growth measure, the geologic growth history of the given oil field structure is revealed quantitatively.

Abstract: A system for surveying the structure beneath the seabed, comprising: a survey vessel; a streamer comprising a cable, a first set of N1 sensor groups positioned at a first end portion of the cable, the sensor groups of the first set being spaced from each other by a group interval, and a second set of N2 sensor groups positioned at a second end portion of the cable, the sensor groups of the second set being spaced from each other by the group interval; a sound source; wherein, when the system is in use, the survey vessel travels at a predetermined speed, towing the streamer and the sound source such that the sound source is positioned adjacent an intermediate portion of the cable between the first and second end portions of the cable; the sound source sends acoustic pulses at a predetermined period between pulses towards the seabed such that reflections are produced towards both the first set of sensor groups and the second set of sensor groups; and the speed of the survey vessel and the predetermined period o

Abstract: A downhole installation comprises: a first pipe layer 8, a second pipe layer 10 about the first pipe layer 8, an annulus 12 between the first pipe layer 8 and the second pipe layer, and a geological formation out-side of the second pipe layer 10.

Abstract: Data obtained with an electromagnetic energy transmitter in borehole to surface electromagnetic (BSEM) transmitter is processed. The processed data provides measures of detected electromagnetic fields, induced polarization and electromagnetic well logging information of interest for surveying and mapping of subsurface formations.

Abstract: Example computer-implemented methods, computer-readable media, and computer systems are described for accurate localization of wireless sensor devices in underground oil reservoirs. In some aspects, every sensor measures respective received magnetic field strengths (RMFSs) on a plurality of respective magnetic induction (MI) links and transmits the measured respective RMFSs to at least one anchor devices. A set of distances is determined from the measured respective RMFSs. The set of distances is processed through an ordered sequence of algorithms, namely weighted maximum likelihood estimation (WMLE), semi-definite programming (SDP) relaxation, alternating direction augmented Lagrangian method (ADM), and conjugate gradient algorithm (CGA), to generate accurate localization of the wireless sensor devices in underground oil reservoirs.

Abstract: An embodiment of a nuclear magnetic resonance (NMR) apparatus for estimating properties of an earth formation includes an NMR measurement device including a transmitting assembly configured to emit a pulse sequence and a receiving assembly configured to detect an echo train based on the pulse sequence, and a processor. The processor is configured to perform receiving input parameters including an axial speed of the NMR measurement device and a T1 value associated with a selected formation fluid, analyzing polarization data associated with the T1 value, the polarization data describing a dependency between polarization and axial speed, determining a wait time for the pulse sequence based on the polarization data, applying the pulse sequence with the determined wait time to the transmitting assembly, and estimating a property of the earth formation based on the echo train detected by the receiving assembly in response to the pulse sequence.

Abstract: A neutron detector system for discriminating fissile material from non-fissile material wherein a digital data acquisition unit collects data at high rate, and in real-time processes large volumes of data directly to count neutrons from the unknown source and detecting excess grouped neutrons to identify fission in the unknown source. The system includes a Poisson neutron generator for in-beam interrogation of a possible fissile neutron source and a DC power supply that exhibits electrical ripple on the order of less than one part per million. Certain voltage multiplier circuits, such as Cockroft-Walton voltage multipliers, are used to enhance the effective of series resistor-inductor circuits components to reduce the ripple associated with traditional AC rectified, high voltage DC power supplies.

Abstract: In accordance with embodiments of the present disclosure, a rotary steerable tool and a gamma sensor assembly are provided. These systems may include scintillation detection sensors mounted in a pressure sleeve assembly coupled to a rotating drive shaft and/or an electronics insert of the rotary steerable tool. The sensors may each be mounted in an atmospheric pressure environment within a respective pressure sleeve. The pressure sleeves may each rotate with the drive shaft and the electronics insert. The sonde-based arrangement of the systems may facilitate relatively high sensitivity measurements taken at a rotating portion of the rotary steerable tool. This may allow directional gamma measurements and bulk gamma measurements to be determined at the rotating section of rotary steerable tool.

Abstract: A system and method for computing radar based precipitation estimates using inverse distance weighting is provided. In an embodiment, an agricultural intelligence computer system receives first electronic digital data comprising a first plurality of values representing precipitation gauge measurements at a plurality of gauge locations. The agricultural intelligence computer system obtains second electronic digital data comprising a second plurality of values representing radar based precipitation estimates at the plurality of gauge locations.

Abstract: Methods, systems, and computer program products for cloud coverage estimation by dynamic scheduling of a distributed set of cameras are provided herein.

Abstract: A method for producing an optical element having a main body with a first side surface, which has a first optical coating, and at least one second side surface, which is not plane-parallel to the first side surface and has a second optical coating, is proposed. The method includes the steps of: determining the stress induced in the optical element by the first optical coating of the first side surface; determining a counter-stress, so that the resultant overall stress induced in the optical element is as small as possible; determining the second optical coating while taking into account the determined counter-stress and the optical parameters of the second optical coating; applying the first optical coating on the first side surface; and, applying the second optical coating on the at least one second side surface.

Abstract: The present invention provides an anti-glare film for touch-mode displays, which has good blackness and touch feel, and a polarizing plate and an image display device comprising the same.

Abstract: Provided is a sheet-form transparent molding for use for a transparent screen, satisfying both visibilities of a projected light and a transmitted light by anisotropically scattering and reflecting the projected light emitted from a light source. A sheet-form transparent molding according to the present invention comprises a transparent light scattering layer comprising a resin and bright flake-form microparticles.

Abstract: Provided are a light diffusion film having a single-layered light diffusion layer, in which the uniformity of the intensity of diffused light in the light diffusion angle region can be increased, or the light diffusion angle region can be expanded effectively, by regulating the combination of the angles of inclination of pillar-shaped objects in plural columnar structure regions, and a method for manufacturing a light diffusion film. Disclosed is a light diffusion film having a single-layered light diffusion layer, the light diffusion film having a first columnar structure region and a second columnar structure region, in which plural pillar-shaped objects having a relatively high refractive index are arranged to stand close together in a region having a relatively low refractive index, sequentially from the lower part of the film along the film plane.

Abstract: A multilayer polymeric reflector is provided which comprises: a) a plurality of first optical layers, each first optical layer comprising a polyester having terephthalate comonomer units and ethylene glycol comonomer units, the polyester having a glass transition temperature, where each first optical layer is oriented, and b) a plurality of second optical layers disposed in a repeating sequence with the plurality of first optical layers, each second optical layer comprising a blend of polymethyl methacrylate (PMMA) and polyvinylidene fluoride (PVDF), where the blend has a glass transition temperature less than the glass transition temperature of the polyester comprising the first optical layers, and where the amount of PVDF in the PMMA/PVDF blend is greater than and not equal to about 40% and not more than about 65%. Articles comprising the multilayer polymeric reflector are also provided.

Abstract: An imaging method includes receiving electromagnetic radiation with a plurality of qualities from a scene to be captured at a mask and passing a first portion of the received electromagnetic radiation having the plurality of qualities present in the received electromagnetic radiation through the mask. One or more qualities of the received electromagnetic radiation is removed from a second portion of the received electromagnetic radiation, and the second portion of the received electromagnetic radiation absent the one or more removed qualities is passed through the mask.

Abstract: Disclosed herein are systems, methods, and apparatus for forming low emissivity panels. In some embodiments, a partially fabricated panel may be provided that includes a substrate, a reflective layer formed over the substrate, and a barrier layer formed over the reflective layer such that the reflective layer is formed between the substrate and the barrier layer. The barrier layer may include a partially oxidized alloy of three or more metals. A first interface layer may be formed over the barrier layer. A top dielectric layer may be formed over the first interface layer. The top dielectric layer may be formed using reactive sputtering in an oxygen containing environment. The first interface layer may prevent further oxidation of the partially oxidized alloy of the three or more metals when forming the top dielectric layer. A second interface layer may be formed over the top dielectric layer.

Abstract: To provide a near-infrared absorption composition capable of forming a film having excellent visible transparency and near-infrared shieldability, a cured film, a near-infrared absorption filter, a solid-state imaging device, and an infrared sensor. A near-infrared absorption composition includes a compound represented Formula (1) and a resin, the compound has a maximum absorption wavelength in a wavelength range of 750 to 830 nm in a film in a case where the film is formed using the near-infrared absorption composition, and a value obtained by dividing an absorbance at a wavelength of 555 nm by an absorbance at the maximum absorption wavelength is 0.10 or less.

Abstract: A process of forming a polymer with a blue light absorber chemically bonded to a polymeric backbone of the polymer includes mixing one or more olefin monomers with one or more functionalizedp-vinylstyrylanthracene monomers to form a mixture of reactants. The mixture includes less than 10 percent by weight of the one or more functionalizedp-vinylstyrylanthracene monomers. The process also includes polymerizing the mixture to produce a polymer with one or more blue light absorption characteristics.

Abstract: According to an embodiment a device comprises: an image sensor, an optical system comprising at least one lens, and an infrared, IR cut-off filter, transmission characteristics of the IR cut-off filter comprising a ripple with low transmission between wavelengths corresponding to blue and green.