Abstract: An image data generating device has a photoelectric sensor including an array of pixel generating units, each of which has one photoelectric conversion element and one floating diffusion. The photoelectric sensor includes a matrix of pixel sets, each of which includes a matrix of pixel generating units on two rows and two columns. To generate plane image data, the image data generating device finds a pixel value on a pixel basis from an output value for each pixel generating unit. To generate distance image data, the image data generating device finds a distance to a subject for each pixel set from an output value for each pixel generating unit belonging to the pixel set and calculates a pixel value per pixel set.

Abstract: A light beam is detected/localized by multisector detector—quad-cell, or 5+ sectors handling plural beams. Preferences: Beams focus to diffraction limit on the detector, which reveals origin direction by null-balance—shifting spots to a central sector junction, and measuring shifts to reach there. One or more MEMS reflectors, and control system with programmed processor(s), sequence the spot toward center: following a normal to an intersector boundary; then along the boundary. One afocal optic amplifies MEMS deflections; another sends beams to imaging optics. After it's known which sector received a spot, and the beam shifts, source direction is reported. The system can respond toward that (or a related) direction. It can illuminate objects, generating beams reflectively. Optics define an FOR in which to search; other optics define an FOV (narrower), for imaging spots onto the detector. The FOR:FOV angular ratio is on order of ten—roughly 180:20°, or 120:10°.

Abstract: A method for calculating a distance to an object is provided. In this method, whether luminances received by at least one light receiving elements of a plurality of light receiving elements are equal to or higher than a predetermined value is determined. When luminances received by at least one light receiving elements are equal to or higher than a predetermined value, whether the luminances change in a time-series manner or not is determined. When the luminances change in a time-series manner, information is acquired from the time-series change. Then, a size of a light receiving region is detected based on a ratio of a light receiving element having received luminance with a predetermined value or more to the plurality of light receiving element. Based on the size of the light receiving region and the acquired information, the distance to the object is calculated.

Abstract: Device and process for determining a distance to an object. The device includes a low coherence light source, at least one lens arranged to focus light from the low coherence light source onto the object and to collect light reflected and scattered from the object, and a window arranged between the lens and the object. An apertured element includes a circular aperture structured and arranged to form a circular light beam from the reflected and scattered light, and a detector system is structured and arranged to receive the circular light beam. The detector system is sensitive to light beam diameter. Further, a determining device is structured and arranged to determine a distance to the object based upon signals from the detector system.

Abstract: A focusing method is provided for the high speed digitalization of microscope slides using an imaging device, wherein the slide is divided into fields of view according to the imaging device and focusing is performed. During rough focusing, several images are captured within the focus range using large focus steps. On the basis of this set of images the position of the best contrast is determined. Fine focusing is performed by adjusting the focus according to the focus distance already determined for another field of view and by focusing with fine steps. A slide displacing device is provided, which enables the displacement of a slide parallel to the optical axis. The slide displacing device includes slide holding elements affixed to one side of a supporting member having two parallel sides, which are connected by stiffening elements defining at least two parallel planes.

Abstract: A distance measuring apparatus includes a detecting unit which detects a distance to an object located in a predetermined detection range; an imaging unit which generates an image signal group corresponding to a predetermined imaging field; a calculating unit which calculates the distance to the object located in the imaging field based on the image signal group; and an interpolating unit which either interpolates a detection result by the detecting unit by using a calculation result by the calculating unit, or interpolates the calculation result by the calculating unit by using the detection result by the detecting unit.

Abstract: A surveying instrument performs tracking of a target by controlling an orientation of a measuring unit relative to the target in two different angular directions. The control in one angular direction is based on detected light intensities which are modulated according to a first time pattern, and control of the orientation in the other angular direction is based on detected light intensities modulated according to a second time pattern just different from the first time pattern.

Abstract: A compact, power-saving laser distance finder with high accuracy is disclosed having a laser generating device, a collimating lens in an emitting end direction of the laser generating device, a receiving lens, an optoelectronic detector, a reflective member rotatably mounted on an optical path of the collimating measuring beam via a rotating shaft and being capable of rotating to a blocking position and an non-blocking position. There is a transmission part on one end of the reflective member, the transmission part has an interval apart from an axis of the rotating shaft and engages with teeth of a worm driven by motor. When the reflective member reaches a predetermined position, it can be kept at that position through self-locking of the engagement between the worm's teeth and the transmission part without supplying power to the motor continuously, and a distance measuring is carried out and accuracy ensured.

Abstract: This invention relates to a ranging apparatus capable of ranging simultaneously to a three dimensional scene. An illumination means (22) illuminates a scene with a two dimensional array of spots (12). A detector (6) is located near to the illumination means (22) and arranged to look toward the scene. A processor (7) responds to the output from the detector (6) and, from the location of a spot in the image of the scene, determines the range to that spot. A variety of techniques are used to resolve ambiguity in determining which projected spot is being considered.

Abstract: A data processing system, computer implemented method, and computer program product code determines distances to an object. Computer generated environments can be calculated therefrom. A light source is focused on an object at an unknown distance from an imaging device, creating a point-of-light. The imaging device, focused on a focal plane at a second location, records an out-of-focus image of the point-of-light at the first distance. From the out-of-focus image, the diameter of a circle of confusion for the point-of-light is identified. The distance between the object and the imaging device is then calculated from the circle of confusion.

Abstract: A pedestrian detection device, a related method, an air bag system and a vehicle are disclosed. The pedestrian detection device 20 includes an infrared ray sensor 30A, which detects a temperature of a detection object approaching to or in contact with the vehicle 10 to provide a temperature signal, an impact sensor 27a to 27c, which generate impact signals when the vehicle encounters a collision, and an impact collision generation unit 21 operative to generate a pedestrian collision signal upon discrimination that the detection object is a pedestrian, discrimination that the impact signal is being outputted, and discrimination that a direction in which the pedestrian is present and a direction in which the impact is applied to the vehicle falls in a substantially same direction.

Abstract: A system comprising an imaging device and a passive-optical range-finder to focus, on the imaging device, a magnified image of a target positioned in a focal plane of the passive-optical range-finder. The system receives information indicative of a target type and generates information indicative of an absolute geographic location for the target based on at least the target type and information output by the imaging device.

Abstract: A data processing system, computer implemented method, and computer program product code determines distances to an object. Computer generated environments can be calculated therefrom. A light source is focused on an object at an unknown distance from an imaging device, creating a point-of-light. The imaging device, focused on a focal plane at a second location, records an out-of-focus image of the point-of-light at the first distance. From the out-of-focus image, the diameter of a circle of confusion for the point-of-light is identified. The distance between the object and the imaging device is then calculated from the circle of confusion.

Abstract: An appropriate adjustment can be made on the basis of a gradation amplitude obtained from a photographing image even when the zoom position of a zoom lens is changed. According to exemplary embodiments a CPU obtains a zoom amount transmitted from a zoom lens position detecting section, and derives the width of a stripe element in a pattern image to be formed on a liquid crystal light valve on the basis of the obtained zoom amount by referring to a stripe element width table stored to a stripe element width table storing section. The CPU corrects the pattern image for an adjustment on the basis of the derived stripe element width and rewrites the contents of a pattern image memory and gives instructions of image projection to an image processing section, a liquid crystal light valve driving section, etc. Thus, the pattern image corrected with respect to the stripe element width is formed on the liquid crystal light valve.

Abstract: A method and system for determining range to a target are provided. A beam of electromagnetic energy is transmitted through an aperture in an opaque screen such that a portion of the beam passes through the aperture to generate a region of diffraction that varies as a function of distance from the aperture. An imaging system is focused on a target plane in the region of diffraction with the generated image being compared to known diffraction patterns. Each known diffraction pattern has a unique value associated therewith that is indicative of a distance from the aperture. A match between the generated image and at least one of the known diffraction patterns is indicative of a distance between the aperture and target plane.

Abstract: A storage unit is configured to store beforehand a table that shows a relation between spread parameters and command values supplied to a control unit to acquire a focused image of an object, and information that designates a command value corresponding to an inflection point on an approximated curve showing the relation that the spread parameters have with the command values, the control unit being configured to control a state of an optical system in accordance with an input command value. The luminance information about the object that lies at a distance falling within a range over which focusing should be detected is acquired, at the position of the optical system, which is obtained by the command value corresponding to the inflection point shown in the table.

Abstract: A system to determine the distance to an object includes one or more aberrating elements to introduce aberration into light from the object. Image data is obtained at two different focus conditions, and used to determine the object distance.

Abstract: A method is disclosed for measuring distance from a camera to parts of a scene using a characterization of perspective distortion in a photograph of the scene. In one example embodiment, a first distance measurement is obtained from the camera to a first point in the scene, the perspective distortion is characterized, and the distance to at least one other point on a plane in the scene is computed based on the first distance measurement and the perspective characterization.

Abstract: A method of inhibiting a subject's eyes from being exposed to projected light when the subject is positioned in front of a background on which an image is displayed comprises capturing an image of the background including the displayed image, processing the captured image to detect the existence of the subject and to locate generally the subject and masking image data used by the projector to project the image corresponding to a region that encompasses at least the subject's eyes, the image data masking compensating for differing camera and projector viewpoints.

Abstract: An auto focusing mechanism is provided in a surveying instrument, such as an electronic level, that is capable of automatically focusing a telescope on a sighted staff. As a focusing lens (21b) is moved by a motor (41) along the optical axis of a telescope (20), the image of a staff (1) sighted by the telescope (20) is converted into an electrical signal by a line sensor (24). The output signal of the line sensor (24) is converted into a digital signal by an A/D converter (27) and stored in a RAM (28). Based on the data stored in the RAM (28), a microcomputer (3) monitors frequencies of the component signals, or wavelets, contained in the output signal of the line sensor (24) stored in the RAM (28). When a particular frequency of the output signal associated with the position of the focusing lens (21b) is detected a determination is made that the focusing lens (21b) is located at a focusing position, and the distance from the telescope (20) to the staff (1) is calculated.

Abstract: A radiometer includes a sighting system that generates a digital image of an object surface having an area that is to be imaged onto the IR detector. A shape outline is overlaid on the digital image of an object surface to indicate the extent of the energy zone that is imaged onto the IR detector. A distance entering interface is used to enter distance data indicating the distance between the radiometer and the object surface and the distance data is utilized to determine the size of the overlaid shape.

Abstract: A system for automatic mapping of a walled structure includes at least one mobile unit, preferably worn by a user. The mobile unit has a position tracking system for tracking a current position of the mobile unit, a wall detection system including a sensor arrangement for measuring range data from the mobile unit to at least four points, and a mapping processor associated with both the position tracking system and the wall detection system. The mapping processor processes the range data and, if the at least four points lie on a common plane according to a defined criterion, maps a wall in corresponding spatial relation to the current position. The mobile unit preferably also includes a wireless communication link for transmitting and receiving data indicative of the mapped walls to other mobile units and to a remote command control unit.

Abstract: A system to determine the distance to an object includes one or more aberrating elements to introduce aberration into light from the object. Image data is obtained at two different focus conditions, and used to determine the object distance.

Abstract: A distance measuring device is disclosed which can measure the distance to an object located within a known range. The device uses beam splitters and lenses to focus and direct energy reflected from an object onto at least two bi-sensors. The bi-sensors each have an inner sensing area and an outer sensing area. When the device has been properly calibrated, the reflected energy will be focused such that almost all of it will fall into the inner sensing area of one be-sensor when the object is at the minimum distance in the known range and when the object it at the maximum distance almost all of the energy will fall onto the inner sensing area of the other sensor. The distance to an object is calculated by comparing the ratio of the energy on the inner sensing areas of the two sensors with a table of known ratio verses distance values.

Abstract: A method and an apparatus for real-time calculation of receive focusing parameters for beamforming are provided. The apparatus is coupled to the signal input end of the receive beamforming module of an ultrasound imaging system as an independent accessory, including a first accumulator and a second accumulator for calculating a quantified focus coordinate (Fx,Fz); a distance determination circuit for calculating the distance between the quantified focus coordinate (Fx,Fz) and quantified coordinate (Elexj,Elezj) of the j-th array element of a probe; a third accumulator for accumulating the value of i*N/2; and a third summator for reading the output results of the third accumulator and the distance determination circuit, adding both output results up and outputting the added-up result as a reading address of echo data calculated in real time. With the present invention, the system memory resource required is reduced, the circuit is simpler, and the parameter loading is faster.

Abstract: A surveying instrument for projecting a distance measuring light to an object to be measured and for measuring a distance from a reflected light, comprising at least an image pickup unit for picking up an image of a spreading range of the distance measuring light, and a control unit for performing edge extraction from the image captured by the image pickup unit and for judging whether there is an edge or not within the spreading range.

Abstract: The present invention relates to a surveying instrument for measuring the distance to a target to be measured, a horizontal angle, and a vertical angle by use of reflected light. An imager can be connected to the surveying instrument. In addition, an arithmetic processing means can determine a three-dimensional position of a plane part by determining from at least three measuring points an equation that includes the plane part as the target to be measured, and then by associating digital image data to which the plane part belongs with the equation so that the plane part is identified.

Abstract: A distance-measuring optical apparatus for measuring a distance to an object as a target comprises an imaging optical system; an image sensor; a driving section for moving at least the imaging optical system substantially perpendicular to an optical axis; an image sensor control section for outputting a periodical timing signal for designating a timing at which the image sensor takes an object image; and a driving control section for controlling the driving section to reciprocate the imaging optical system. The timing signal is periodically output when the imaging optical system is located near two positions away from each other in a direction substantially perpendicular to the optical axis. The distance-measuring optical apparatus further comprises an image processing operation section for finding, through an operation, a distance from the imaging optical system to the object using the image signal when the imaging optical system is at each of the two positions.

Abstract: A distance measuring apparatus and method in which a target subject is detected from image data obtained through imaging, the distance to the object is calculated based on the size of the target subject, and the distance to the target subject is further measured using a distance measuring sensor. Then, a subject distance is determined according to the size of the detected target subject, and based on the distance to the target subject calculated based on the size of the target subject and/or the distance to the target subject obtained by the distance measuring sensor.

Abstract: A distance measuring method simultaneously measures a distance between a distance measurement system (10A) and a measurement object (M), and a relative speed therebetween. In the method, the distance measurement system sends an electromagnetic wave toward the measurement object as a traveling wave while changing a frequency thereof. The measurement object reflects the traveling wave to produce a reflected wave. The traveling wave and the reflected wave interfere with each other to produce a standing wave. The distance measurement system detects the amplitude of the standing wave and produces an amplitude signal representing the amplitude of the standing wave. Based on the produced amplitude signal, the distance measuring system derives the distance and the relative speed between the distance measurement system and the measurement object.

Abstract: An environment recognition system recognizes a substance moving in relative thereto, with using a modulated beam. A beam emitting means emits a beam. A beam scanning means scans the beam. A beam receiving means detects the beam reflected from the substance. Upon basis of the signal received by the beam receiving means, a distance measuring means obtains a distance image. Comparing plural numbers of the images obtained by the distance measuring means, a distortion removal means removes distortion of the substance contained within the distance image.

Abstract: A system and method are provided for determining a distance to a target. The method includes sending light, at a first time, to a light reflector mounted in a reflector device, receiving light reflected from the light reflector at a second time, and determining the distance to the reflector device using the difference between the first time and the second time. The reflector device has a first lateral surface, a second lateral surface parallel to the first lateral surface, and a rod surface extending from the first lateral surface to the second lateral surface. The reflector device includes sockets arranged in the rod surface with a light reflector mounted in each socket. The sockets may be arranged in a plurality of rows with possibly a plurality of sockets in each row. The reflector device may be mounted as an insert to or at the top of a target to determine the distance to the target.

Abstract: An integrated system generates a model of a three-dimensional object. A scanning laser device scans the three-dimensional object and generates a point cloud. The points of the point cloud each indicate a location of a corresponding point on a surface of the object. A first model is generated, responsive to the point cloud, that generates a first model representing constituent geometric shapes of the object. A data file is generated, responsive to the first model, that can be inputted to a computer-aided design system.

Abstract: Disclosed is a LADAR system and a method for operating same. The LADAR system includes circuitry for generating the electrical signal with an optical signal detector using N discrete samples; a bank of M parallel sample/hold circuit unit cells individual ones of which operate with an associated sample/hold clock, where each sample/hold clock is shifted in time by a fixed or programmable amount ?t relative to a sample/hold clock of an adjacent sample/hold circuit unit cell; and further includes circuitry for sequentially coupling a sampled value of the electrical signal from a first output of individual ones of at least some of the M parallel sample/hold circuit unit cells to an analog to digital converter circuit. Each of the M parallel sample/hold circuit unit cells has a second output for outputting a digital signal for indicating the state (low or high) during a time that the associated sample/hold clock allowing for time of arrival determination.

Abstract: A method and system for detecting a target which uses composition correlation filters with score reaffirmation post processing for acquiring a target. The method and system uses target decision rules that are based on comparing the dot products, or peaks, of three score reaffirmation filters and their registered LADAR image to detect a target.

Abstract: A distance-measuring system, which comprises a light source unit for emitting a distance-measuring light, a photodetection optical system having a photodetection optical axis, a projecting optical system having a projecting light optical axis and for projecting the distance-measuring light from the light source unit to an object to be measured and for guiding the distance-measuring light reflected from the object to be measured toward the photodetection optical system, and an internal reference optical system for guiding the distance-measuring light from the light source unit to the photodetection optical system as an internal reference light, wherein the light source unit can emit two distance-measuring lights with different spreading angles, and one of the light source unit and the projection optical system has a decentering member for decentering the distance-measuring light with respect to the projecting light optical axis.

Abstract: Two light beams from respective light-emitting devices (e.g., lasers or lamps) cross each other and strike a surface (e.g., of a fluid) at respective oblique orientations relative to the surface (e.g., oblique but nearly vertical orientations that are equal and opposite to each other). A camera captures the surface scattering of the beams in a photographic “double-beam” image containing two respective photographic forms corresponding to the two respective surface scattering locations. The measured distance between the two photographic forms is trigonometrically indicative of the height and slope of the surface in the vicinity of the two surface scattering locations. Some inventive embodiments effect “single-beam” images that are trigonometrically indicative of height only. Plural (e.g.

Abstract: Method and device for light signal reception. This device can selectively execute a comparison mode or a gain mode. In the device, a transmitter transmits a light beam to a target. A receiver receives the light beam reflected from the target and outputs a corresponding received signal. In the comparison mode, it is determined whether a pulse in the received signal is higher than a reference voltage level. When the pulse is higher the reference voltage level, the pulse is outputted. The gain mode is executed and the received signal is amplified and output when no pulse is higher than the reference voltage level in the received signal. The method and device of the present invention can be applied to range finders, the comparison mode is executed during short-distance measurement and the gain mode is executed during long-distance measurement thereby measuring the target distance from several meters to a thousand meters.

Abstract: An improved technique for a laser rangefinder includes a pulsed laser sending out a repetition of light pulses and the received signal (light pulse and noise components combined) being analyzed by continuous averaging of successive received signal discrete time sequences, each sequence beginning with the onset of transmitted laser light. Also, a circuit generates high potentials for the laser diode driving circuitry that simultaneously drives the laser diode, having at least one of several beneficial characteristics: It is conveniently synchronous with the light pulse send/receive process to reduce the effects of noise on the receive section. It is energy efficient in converting low battery potentials to higher voltages. Finally, it utilizes a minimized number of components, leading to high product economy.

Abstract: A multifunction rangefinder capable of measuring distance, compass location and altitude. A distance measurement unit capable of long and short distance measurements transmits a light beam to a target, receives a reflected light from the target and outputs a distance measurement signal. A compass measurement unit measures terrestrial magnetism and outputs a compass measurement signal. An altitude measurement unit measures atmospheric pressure to generate an altitude measurement signal. A microprocessor calculates a distance between the target and the multifunction rangefinder, altitude and the compass location of the target according to the distance, altitude and compass measurement signals respectively.

Abstract: A ranging apparatus which determines distances to objects by using planar positions of the objects in images which are obtained by cameras which take the images, plural distortion correction tables used to correct distortion of images taken by the cameras wherein the distortion correction are made for progressively determined ranging distances of a target object, a corrective computer which generates corrected images using the distortion correction tables, being corrected for eliminating distortion caused by optical systems of the cameras, corresponding to the progressively determined ranging distances in which the images are taken by the cameras, a selector which selects a most appropriately corrected image among the corrected images and a ranging computer which computes a distance to the object viewed in the selected corrected image.

Abstract: A radiometer includes a sighting system that generates a digital image of an object surface having an area that is to be imaged onto the IR detector. A shape outline is overlaid on the digital image of an object surface to indicate the extent of the energy zone that is imaged onto the IR detector. A rangefinder measures the distance between the radiometer and the object surface and the measured distance is utilized to determine the size of the overlaid shape.

Abstract: A system and method for automated and/or semi-automated analysis of video for discerning patterns of interest in video streams. In a preferred embodiment, the present invention is directed to identifying patterns of interest in indoor settings. In one aspect, the present invention deals with the change detection problem using a Markov Random Field approach where information from different sources are naturally combined with additional constraints to provide the final detection map. A slight modification is made of the regularity term within the MRF model that accounts for real-discontinuities in the observed data. The defined objective function is implemented in a multi-scale framework that decreases the computational cost and the risk of convergence to local minima. To achieve real-time performance, fast deterministic relaxation algorithms are used to perform the minimization. The crowdedness measure used is a geometric measure of occupancy that is quasi-invariant to objects translating on the platform.

Abstract: An object of the present invention is to determine a kind of a passenger, e.g., adult or child, without executing a complicated image processing, thereby controlling an unfolding of an air bag. The safety apparatus for an automobile crash extracts a head ellipse from an image outputted from an area sensor. The apparatus stores beforehand reference head ellipses of every possible kind of passenger's heads. The extracted head ellipse of the present passenger is selected among the references. Then, a region including the extracted head ellipse is designated to a future processing region for searching the same passenger's head at a time to come. Thus, the passenger's head is recognized simply and rapidly, even when the passenger has moved outside the future processing region.

Abstract: A range finder includes a package, a semiconductor chip, an optical casing, a lens holder, a first lens, and a second lens. The first and second lenses are attached to the lens holder. The lens holder is formed of a material having a thermal expansion coefficient equal or close to that of the semiconductor chip. The range finder is constructed such that a distance between the two lenses and a distance between two light detecting sections on the semiconductor chip do not change significantly relative to each other due to the thermal expansion or contraction.

Abstract: Disclosed is a method that utilizes optics to measure a hole depth in a workpiece. The method involves placing a light recording apparatus and a light source apparatus proximate a hole. Light is then emitted from the light source apparatus and is directed into the hole. This illumination of the hole allows an image of the side surface of the hole that is at the greatest distance from the light recording apparatus to be recorded. Then, the apparent diameter of the image is calculated. The apparent diameter of the image, in turn, is compared to the known diameter of the hole in order to calculate the distance between a reference datum in the light recording apparatus and the far side surface of the hole. Once this distance is determined, the hole depth is calculated by accounting for the distance between the reference datum and the workpiece surface.

Abstract: Laser optical sensing systems and methods for detecting object characteristics are disclosed. The system includes a laser source with at least two emission apertures from which laser signals are emitted. The system also includes at least one detector, which is operationally responsive to the laser source. The system can also include a microprocessor that is operationally coupled to the detector(s) for processing signal data, a memory accessible by the microprocessor for storing object characteristics (e.g., unique signals), and a software module accessible by the microprocessor for enabling system training and detection operations. The laser source emits into an environment at least two laser signals, one from each emission aperture. The detector detects the laser signals after the signals pass through the environment, which is occupied by an object, and the microprocessor determines object characteristics based on the matching of laser signals received by the detector(s) and characteristics stored in memory.

Abstract: An integrated system generates a model of a three-dimensional object. A scanning laser device scans the three-dimensional object and generates a point cloud. The points of the point cloud each indicate a location of a corresponding point on a surface of the object. A first model is generated, responsive to the point cloud, that generates a first model representing constituent geometric shapes of the object. A data file is generated, responsive to the first model, that can be inputted to a computer-aided design system.

Abstract: A method and apparatus for optical odometry are disclosed which inexpensively facilitate diverse applications including indoor/outdoor vehicle tracking in secure areas, industrial and home robot navigation, automated steering and navigation of autonomous farm vehicles, shopping cart navigation and tracking, and automotive anti-lock braking systems. In a preferred low-cost embodiment, a telecentric lens is used with an optical computer mouse chip and a microprocessor. In a two-sensor embodiment, both rotation and translation are accurately measured.

Abstract: Disclosed is an optical measurement apparatus for a living body to provide a means for measuring blood flow activity within a short time inside the body, even if the test subject cannot distinguish between the active task period and the rest period. An optical measurement apparatus for a living body comprises a light irradiating section, and a light detecting section for detecting light transmitting through or reflected from the interior of the body. The concentration of carbon dioxide gas taken into the body is controlled by the respiration of the test subject and the resulting change in output from the light detecting section is then evaluated.