MXPA00002823A - Electronic optical target ranging and imaging - Google Patents

Abstract

A system for optically ranging and three dimensionally imaging of an object. For ranging only a single photodetector can detect light reflected from the object when alternately illuminated by a pair of strobed sources or a shutter strobed direct and virtually imaged single source of light. The detector output signal for each illumination has the ambient only light intensity signal subtracted therefrom and the ratio of direct to virtually imaged light computed and the distance of the object determined from the ratio. For imaging an array of detectors is used and the computed distances mapped using the detector coordinates to give a three dimensional image. Light in the range 350 to 14000 nanometers wavelength is preferred. The system is particularly suitable as a vehicle occupancy sensor and the image used to generate an airbag inflation suppression signal if the image indicates non-acceptable occupant characteristics or position.

Description

RANGE MEASUREMENT AND OPTICAL PICTURE ELECTRONIC PICTURE FORMATION BACKGROUND OF THE INVENTION The present invention relates to devices for measuring range and optically mapping a stationary object. The invention has application in devices for determining the presence and position of the human occupant of a seat in a vehicle. In providing protection against collisions to motor vehicle passengers, particularly with inflatable airbags, it has been found necessary to control the amount or rate of inflation of the airbag according to the position of the occupant with respect to the airbag assembly structure in the moment of inflation. It has also been required to determine the physical size and configuration of the occupant in order to prevent bodily injury in the event that the inflation of the airbag is too sudden or too powerful for the size of the occupant. Such problems have been found with the presence of children and small adults of carving in the front passenger seat of the vehicle. Thus, it has been desired to provide a low-cost and reliable way or means to detect the location or range, size and position of an object, and particularly the occupant of a front passenger seat of a vehicle, of t ^ ^^^^^ J íSto¡ * &? j ^^^^ &? i ^^ * ^^^ * 4te ^^^ a way in which sufficient information can be obtained to provide the rate correct of or the suppression of inflation of the airbag to protect the occupant. So far, it has been proposed to use weight sensing devices in the seat to determine the mass of the occupant in the passenger seat and deduct the size of the occupant from the weight. However, such seat weight sensors do not provide any information about the relative position of the occupant with respect to the airbag, nor any direct information about the size and shape of the occupant. Accordingly, it has been desired to provide other ways or means to determine the configuration and relative position of the occupant's body with respect to the air bag at the time of collision. It has been suggested to use a pair of video cameras for three-dimensional monitoring of the position of the occupant in real time during the operation of the vehicle; however, it has been found that such techniques are prohibitively bulky and obstructive for installation in the vehicle and have also been considered prohibitively expensive for mass production, in large volumes, of motor vehicles. In this way, it has been desired to provide a low cost, compact, simple and easy to install sensor to determine the size and position of an object such as a passenger in a motor vehicle in a seating position that is protected by a Inflatable air bag.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a simple, relatively inexpensive system or device for optically measuring the range of an object with a single camera or photo-detector. It is a further object of the present invention to provide optical range measurement and mapping, with a single camera, of a real-time object for dimensional image formation of the object in real time. It is a further object of the invention to provide optical range and mapping measurement and three-dimensional image formation with a single photo-detection device suitably for real-time monitoring of the size and position of the occupant of a motor vehicle in a seating position that is protected by an airbag. It is a further object of the present invention to provide optical range measurement and three-dimensional mapping of images by a plurality of photo-detector pixels arranged in an array in a solid-state device. It is a further object of the present invention to provide optical range measurement and three-dimensional mapping of images by a single camera in real time and provide an electrical signal that can be used to control the inflation of an airbag for occupant protection of the vehicle against collisions. ** - & , M. i ^ i. * J * sA & ¿. ? -. ^ * r; t *. * .. . . . . , * - * ~, *. .. * * s- Z-íWZ 5r * é & *. .

The present invention uses a single camera having at least one photo-detector for range measurement. For image formation, an arrangement of photo-detectors of solid-state pixels is preferably used to receive and electronically map as a three-dimensional image the light reflected from an object sequentially illuminated by a pair of light sources. The solid state photo-detectors provide electrical signals that can be employed by an electronic computer for a multiplicity of purposes, particularly to provide a signal to suppress the inflation of a protective airbag of the vehicle occupant. In the presently preferred practice of the invention, the light sources emit light, the spectrum having a wavelength in the range of about 350 to 14,000 nanometers. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a perspective view of a module containing the light sources and for illuminating and detecting reflected light from an object, as embodied in the present invention; Figure 2 is a top view of the arrangement of Figure 1; Figure 3 is an enlarged sectional view of a portion of the camera array of Figure 1; Figure 4 is a side view of a seat of í. i a a * iÁ, f3 & z? i? i-z *? ~ passenger of motor vehicle having an occupant, having the invention installed as an occupant position detector; Figure 5 is a top view of the occupant seat portion of the vehicle of Figure 4; Figure 6 is a view similar to Figure 4 showing the alternative location for the lighting module and camera of the present invention, as used in a vehicle for detecting the position of the occupant; Figure 7 is an optical diagram for creating a virtual image of a light source further from the location of the actual light source using a lens, as embodied in the present invention; Figure 8 is an optical diagram showing the creation of a virtual image of the remote light source from the physical location of the light source incorporating a mirror; Fig. 9 is an optical diagram of another embodiment of the present invention employing a single light source and a rotating shutter to alternately direct light from a spherical mirror and a reflection mirror to create a virtual image of the source of light at a distance from the object greater than the actual location of the light source; Fig. 10 is an enlarged detail of the rotary plug of the embodiment of Fig. 9; Figure 11 is a perspective view of an alternate embodiment of the invention, employing a rotary shutter with a lens and an aperture; Figure 12 is an amplified view of an active CMOS pixel array employed for the photo-detector of the present invention; Figure 13 is a view similar to Figure 12 of a passive CMOS pixel array; Figure 14 is a block diagram of the algorithm of the system of the present invention for range measurement and for mapping and three-dimensional image formation of an object 10 with dual light sources and a single photo-detector array; Fig. 15 is a block diagram of the system algorithm as used for a vehicle occupant position sensor; and Figure 16 is a block diagram of the functions 15 of the electrical circuits for the system of the present invention, used for detection of the vehicle occupant and suppression of the air bag. Detailed Description of the Invention Referring to Figure 1, the system of the present invention is generally indicated at 10 and includes a camera module 12 disposed at a predetermined distance L from an object 14 whose range will only be measured or measured and formed in pictures. The module 12 includes a plurality of illuminated illumination sources Ll, L2, arranged preferentially in spaced relationship on opposite sides of a chamber 16 that ^^ gr ^^ j ^^ '- ^^^^^ ^^ r ^^^^^^^^^^^^^^^^ MM || MM ^^^ 1¿M ^ t¡H ^ ^ M ^^ M in the presently preferred practice of the invention uses at least one photo-detector for range measurement only and for imaging of a plurality of photo-detectors, generally indicated at 18, and which will be described in greater detail subsequently, and a focusing lens 20 for range measurement and mapping for three-dimensional image formation of the object 14. Although the illumination sources Ll, L2 are illustrated in the embodiment 10 of FIGS. 1 and 2 as disposed in FIG. a common station or distance L of the object 14, it will be understood that this is done for convenience and compact reason, which is the case for an automotive vehicle occupancy sensor application of the present invention. It will be understood, however, that the sources Ll, L2 can be located at different distances from the object for other applications, where space allows. In the presently preferred practice of the invention, the system 10 of the present invention, which is of the type intended for an automotive vehicle occupancy sensor application, a lens 22 is disposed adjacent to the source L2 and located between the source L2 and the object 14 to provide a virtual image of the source L2 to the objects, as will be described later. It will be understood that for applications where the sources Ll and L2 are located at different distances from the object, the lens 22 is not needed.

Referring to Figures 2 and 3, the camera 16 preferably employs a suitable optical filter 21 in front of the lens 20, to improve the signal to noise ratio of the reflected light of the object 14. Referring to Figure 7, the lens 22 has a focal point denoted by the reference characters FP, which is more distant from the lens 22 than the source L2, which is indicated as a distance DL2 from the lens 22. The rays of the source L2 that pass through the lens they would be observed by an observed located in the object 14 as emanating from the virtual image having a location in IL2, as shown in figure 7, and denoted as a distance DIL2 from the lens 22. The virtual image IL2 is located at a distance dd from the source L2 and a distance D02 from the object 14. In this way, the lens 22 creates the effect that the object 14 is illuminated by the source L2 as if L2 were physically located at the distance D02 of object 14 (DIL2 from lens 22), unlike the distance DI (L in figures 1 and 2) to which both sources Ll, L2 are physically located. As will be understood by those skilled in the art, the illumination of an object by a light source is inversely proportional to the square of the distance from the source and directly proportional to the intensity of the source. In this way, if the sources Ll and L2 are of the same intensity and wavelength, the object 14 will be illuminated in the arrangement of the 2 as if the source Ll were at a distance L and the source L2 at a distance D02 from the object 14. It will be further understood that the illumination of the object 14, at any instant in time or frame, is a sum of the light environmental and the light of either the Ll or L2 source, which are illuminated sequentially or alternately. The present invention obtains range and image information by recording the intensity of illumination of the object 14 with ambient light only and records the signal output of the photo-detectors 18. Subsequently, the sources Ll, L2 are energized alternately for a brief moment; in the current practice of the invention, a range of 10 milliseconds has been found satisfactory; and the output of the photo-detectors 18 for illumination by each of the sources Ll, L2 is converted to digital form and stored in memory. The output of the photo-detectors 18 previously obtained with ambient light can only then be subtracted from each of the photo-detector outputs for illumination by the sources Ll., L2, respectively. The ratio of the squares of the value for the signals obtained by the subtraction of each source illumination can be calculated. This relationship can then be used to calculate the distance of the object from the photo-detectors while the relation of the illumination will vary according to the distance of the object from the photo-detectors. The calculations for a given pixel are established as follows. Referring to Figure 7, for a given lens 22 having the focal point FP located at a distance FL from the lens and the source L2 located at a distance DL2 from the lens, the distance of the virtual image IL2 from the lens DL2 is DIL2 = | FLx DL2 / FL-DL2 | If L12 is the same real distance DI from the object, the difference in the virtual distance is calculated as dD = DIL2 - DL2 The light received in a given photo-detector or pixel can be described by the following expression: Ipx = Ia + K / d2, while Ia is the intensity of the light received without any of the sources Ll, L2, and the term K / d2 is a function of a light source at a distance d from the object. The K factor is an empirically determined function, known, of the intensity of the illumination and the reflectivity of the object. Re-fixing the above, you have to K K I "=" "c2 J '(lpx ~) Given the two sources Ll, IL2 at distances DI and D02, respectively, from the object, the actual distance to the object can be calculated if the sequential lighting measurements (pictures) are taken and the distances between Ll and IL2 are known: The relation is then taken to eliminate the term of reflectivity From figure 7, it is observed that dD = D02 - Di or Di = D02 - dD 10 Therefore, substituting so that distance D02 can be written in terms of dD: In current practice, for a vehicle occupant sensor where mapping and imaging is desired, the photo-detectors are preferably an array of pixels, comprising either an active solid-state array 18, shown in Figure 12 , or a passive solid state array 18 ', shown in Figure 13, arranged in a solid state CMOS device. Each of the pixels shown in the arrangements illustrated in Figures 12 and 13 in this manner has a pair of Cartesian coordinates X, Y, which can be used to create a map of the reflected light intensities of object 14 in the coordinates particulars for each pixel. The intensity of the reflected light HBi¡- > - * «* • '- • * • - • * * ^^ -' • lUj aa¡iiMH ^ IHla? JmUuta ***. ..- A ..,., * ** ^ of object 14 will vary for each pixel, depending on the shape of the object and the distance of the discrete point in the object corresponding to the X coordinate, and for a given pixel. In this way, the distance determined from the calculated value of the ratio of the intensities for a given pixel, being a function of the distance of the portion of the object from which the reflected light pixel is received, can be mapped, using the coordinates of the pixel, to give a three-dimensional image of the object. The present invention in this manner provides a simple and relatively inexpensive technique for measuring the range of an object using alternately energized sources of illumination and at least one photo-detector which may comprise one or a plurality of pixels in a solid state device common. Additionally, if a plurality of photo-detectors are used, preferably in an array, three-dimensional imaging of the object can be achieved. Referring to Figure 8, an alternate array of the virtual source IL2 is illustrated, where the lens 22 is replaced by a concave mirror 24 having the source L2 disposed between the focal point of the mirror FP '; and a shield 26 is provided to prevent light from the source L2 from directly illuminating the object 14. The mirror 24 has a virtual image IL2 'which is a considerable distance behind the mirror from the physical location of the source L2, thus creating a greater apparent distance D02 'of the source L2 from the object 14. Referring to Figures 4 and 5, the present invention is shown to be applied as an occupant position sensor for range measurement and imaging of an occupant, denoted generally at 28, sitting in the front seat 30 of a motor vehicle 32 with the camera module 12 disposed in the vehicle in front of the occupant and on the windshield. In a further alternative arrangement, the module 12 may be located at the head of the vehicle on the seat of the occupant 30 ', as shown in figure 6. In the arrangement of figure 6, the light sources Ll, L2 are arranged alternately on one side of the photo-detector 18 '. Referring to Figures 9 to 11, an alternative arrangement of the invention is shown using a single light source L3 with a rotary shutter assembly, indicated generally at 38, which includes a motor 40 connected to rotate the wheel 42, which it has a blackened, non-reflecting, generally curved shield 44 thereon, and a flattened reflecting mirror 46 aligned on a common radius of the wheel 42 and on the same side of the center of the wheel. The source L3 has a stationary shield 48 arranged to prevent direct illumination of the target 14 by L3; and a concave mirror 50 is disposed on the opposite side of L3 from the shield 48 such that upon energization of the source L3 occurs, the object 14 is A ^^ S illuminated by reflected rays from the concave mirror 50. The object 14 in the arrangement of Figure 9 is illuminated as if the source L3 were located at the virtual image point IL3, which is considerably further from the object 14 than the physical location of L3. This is the condition of the system with the wheel 42 shown in the solid profile position in Figure 9, where the mirror 46 and the shield 44 are rotated behind the concave mirror 50. With the wheel 42 rotated to a position where the shield 44 and the mirror 46 are located in the position shown in dotted profile in Figure 9, the mirror 50 is isolated from the source L3 by the shield 44; and the light of L3 reflected from the flattened mirror 46 to illuminate the object 14 in a manner that is almost direct illumination. In this way, the rotation of the shutter wheel 42 produces alternating illumination of the object 14 from the physical location of the single source L3 and from the virtual location in IL3. Referring to Figure 11, there is illustrated another alternative arrangement of the single source illumination from a lamp L3 ', where a lens 52 is mounted on a rotating sealing wheel 42' driven by the motor 40 ', with the lens 52 arranged diametrically opposite on the wheel 42 'from an aperture 54. The rotation of the wheel 42' in this manner allows illumination of the object 14 alternately by direct illumination through the aperture 54 and by the light passing through the lens 52 and that has a virtual image point IL3 'to a «You fete% > - * at a considerable distance behind the lens 52, such that the illumination intensity of the object 14 is substantially different through the lens 52 and aperture 54 of the single source L3 '. Referring to Figure 14, the operation of the system is shown in block diagram form, where the intensity of the illumination of the object 14 with only ambient light is detected by the photo-detectors 18 in step 60. The ambient light is then filtered in step 62 for intensities known to be optically insignificant. The system then proceeds to the strobe or energizing source Ll by a range selected in step 64, which may be chosen short enough to ensure that no significant movement of the object occurs during illumination. In the current practice of the invention, a period of ten milliseconds for a vehicle occupant sensor application has been found satisfactory; however, other periods of time may be used, as the application justifies. The system then proceeds to step 66 and records the intensity of the reflected light received from the object for each pixel in array 18. Referring to FIG. 14, the system proceeds to step 68 and performs a digital filtering operation to remove the effects of ambient light for the values of the signals produced by each of the pixels. The system then proceeds to step 70 and energizes or submits to stroboscope the source L2 to illuminate the object 14 and with the source Ll off. The system then proceeds to step 72 and stores in memory digital signals formed from the output signals of each of the pixels during the illumination of step 70 for the source L2. The system then proceeds to step 74 and performs a digital filtering operation to subtract or remove the stored value of the signal for ambient light for each of the pixels to thereby produce the stored values of the signal representative only of the lighting source L2. The system then proceeds to step 76 and performs calculations to calculate the distance ratio D02 of the stored signals for each pixel for illumination with respectively Ll, L2 and proceeds to step 78 to map the distances determined in step 76 using the coordinates for each pixel, thereby creating a three-dimensional image of the object in step 80. The system in performing the operations in step 78 compares the calculated values with calibrated data stored in memory from manufacturing operations, which are shown in Figure 14 as data obtained from the calibration data stored in memory in step 79. Referring to Figure 15, the operation of the system is shown in a flow diagram for the application of the present invention in a position sensing application of the motor vehicle seat occupant, wherein the system in the vehicle responds to the starting of the vehicle in step 100 to carry out an adjustment in step 102 in the sources Ll, L2 with based on the environmental data recorded in step 60. The system then proceeds to carry out the depth mapping operation 60 to 80 of FIG. 14 in step 104, and proceeds to step 106 and performs a test of a condition in risk based on the entry of data into the system from memory in step 106. If the test in step 106 is affirmative, the system proceeds to step 108 and generates a signal to the airbag inflator control system, recommending suppression of the air bag. The system then returns to step 104. However, if the determination in step 106 is negative, the system is recycled to step 104. Referring to FIG. 16, the function of the electrical system of the present invention, as embodied in FIG. A vehicle occupancy sensor application is illustrated in block diagram form and will be described later. The system captures images of a pre-defined area within a vehicle passenger compartment, stores the image data in memory and processes the image data using programmed software in electronic circuit devices such as a microprocessor. The image data processing provides a passenger-side occupant classification in the front seat of the vehicle and a determination of whether an object in this seat is in the "at-risk zone". If this is the case, the system will instruct an external device to suppress or enable the activation of the air bag inflator on the passenger side. During the manufacturing process, specific information to the vehicle is programmed in the non-volatile memory 224. When the system is activated, the occupant classification processor 230 reads the contents of the non-volatile memory 224 and sets the system operating parameters in the processor 230 and in the field-at-risk (FPGA) programmable gate array 210. The FPGA 210 instructs camera 220 to take "photographs". The photography data is routed from the camera 220 through the FPGA 210 and stored in the internal RAM memory of the FPGA and the image RAM OC 218. When a frame or complete frames of photographs have been stored in the RAM memory of OC 218, the FPGA 210 notifies the optical coupler (OC) 230. The OC 230 processes the photo data in the image RAM OC 218 and determines the occupant classification of the passenger side. The image RAM data OC 218 is routed through the FPGA 210 and the data link bar OC during OC data processing.

The FPGA 210 processes photo data from its internal RAM to determine if an object is in the area at risk. As a result of OC and FPGA image data processing, the system will send a message to an external device via an on-board transceiver 232 and the processor card connector 234, recommending whether to suppress or enable activation of the airbag inflator the size of the passenger. The system contains lighting circuits to illuminate the passenger compartment of the car, consisting of IR 208 LED exciters, near intensity control 200, far intensity control 202, near infrared LEDs 204 and infrared LEDs far 206. It will be understood that the LEDs 204 and 206 correspond to the light sources Ll, L2 described in the foregoing. The far-control signal turns on / off the far-infrared LEDs 206 by connecting the appropriate IR LED exciters 208 in gate. The near-control signal turns on / off the near infrared LEDs 206 by connecting in gate the appropriate IR LED exciters 208. An internal register within the FPGA 210 controls the logical state of these signals. The OC 230 writes the contents of this record. The intensity-control and intensity-data signals are used to control the magnitude of the current connected in the gate to the infrared LEDs. An internal register within the FPGA 210 controls the logical state of these signals. The OC 230 writes the contents of this record. - * - '' --'- k ~ '-tMI-tt *. *****. *** *. > **,, "?,? «Tw? * * **** 2, ^ * The FPGA 210 controls the state of the (external) status LEDs 214. An internal register within the FPGA 210 controls the logic state of these signals. The OC 230 updates the contents of this record. The FPGA 210 generates the appropriate timing and control signals during read or write accesses of the OC 230 to the peripheral devices. The image data processing software programs of the OC 230 and other software programs reside in flash ROM 226. The extra RAM memory space required by the OC is provided in the OC 228 user RAM. of the clock required by the internal circuits of the FPGA and the OC are derived from the oscillator circuits 212 and 236, respectively. The non-volatile memory 224 is also used to store system fault codes. The on-board power source 222 generates the 5.0 and 3.3 volt power signals required by the components of the various circuits of the system. The present invention in this way provides, in its simplest form, a unique and novel system for measuring the optical range of an object using a single photo-detector with alternately stroboscopic sources of illumination and calculates the ratio of the light received in the detector and makes a determination as to the range of the object that is reflected to the detector. In another embodiment, a plurality of photo-detectors are used; and the alternate stroboscope of the light source *. . * *: * í. , *, * - • ^. ** ¡h *** - **. ** l -. ~ < m a *? ** ?? t **? ** - '- - - > • »> * - * - * * *? * n? *. ~ allows the system to digitally map the calculated distances from the ratio of the light received by each detector when stroboscopied in this way to allow mapping to create a three-dimensional image of the object . The system of the present invention can be operated with the lighting sources physically spaced at different distances from the illuminated object or co-located with reflecting lenses or mirrors used to create a virtual image of one of the sources to induce the effect of the differences in the distance of the sources from the illuminated object. In an alternative embodiment, a single light source with shutter is used for alternate transmission of light from the source, either through a lens or a mirror to the object, to create a virtual distance other than the physical location of the light source. the source and through a simple opening for direct lighting. Light in the range of about 350 to 14,000 nanometers in wavelength is preferably used from sources Ll, L2, L3. Although the invention has been described above with respect to the illustrated embodiments, it will be understood that The invention is capable of modifications and variations and is limited only by the following claims.

Claims (37)

1. CLAIMS 1. A method of measuring the range and optically forming an object, comprising: (a) arranging a first light source at a certain distance from said object and illuminating said object with said first light source; (b) arranging a second source of light at a distance from said object that is virtually different from said certain distance and illuminating said object with said second source; 10 (c) arranging a plurality of photo-detectors in an array to detect light reflected from said object, and generating an electrical signal indicative of the intensity of the reflected light detected by said detectors; (d) alternately energizing said first and second second sources and focusing the reflected light from the object to said detector; (e) storing the values of said generated electrical signals when said object is first illuminated with one of said first and second sources and then with the other of said 20 first and second sources; and (f) calculating the ratio of said signal values generated for the detector when it is illuminated with said one and then the other of said sources and calculating from said relation the distance of the object from said detector and mapping 25 said distances calculated as an image of said object.
2. 2. The method defined in claim 1, wherein said step of illuminating said object includes illuminating with light having a wavelength in the range of about 350 to 14,000 nanometers. The method defined in claim 1, wherein said step of arranging photo-detectors includes arranging said plurality of detectors in any arrangement. The method defined in claim 1, wherein said step of arranging said photo-detectors includes arranging an array of pixels in an integrated solid-state device. The method defined in claim 1, wherein said step of virtually providing said second source at a virtually different predetermined distance includes disposing a lens between said second source and said object. The method defined in claim 1, wherein said mapping step includes converting said electrical signals from analog to digital form. The method defined in claim 1, wherein said step of arranging photo-detectors includes arranging said arrangement of detectors between said first and second sources. The method defined in claim 1, wherein said focusing step includes passing said reflected light through a lens. The method defined in claim 1, wherein said focusing step includes reflecting said light from said **.: i .... .. < > *** - < ** * -, * -. ,. ^ ** **. *** i.-u * ^. ***** ^ ** ** ". * ** a * .M. . ,. *. * * ^ m ^ ám,. * .. Object with a mirror. The method defined in claim 1, wherein said focusing step includes passing said reflected light through an aperture. 11. The method defined in claim 1, wherein said step of illuminating includes reflecting light from one of said first and second sources with a mirror. 12. The method defined in claim 1, wherein said step of arranging said photo-detectors includes arranging a 10 arrangement of pixels in a solid-state device selected from the group consisting of (a) a load-coupled device and (b) a CMOS device. The method defined in claim 1, wherein said step of arranging said photo-detectors includes arranging a 15 solid-state device selected from the group consisting of (a) an active pixel array sensor and (b) a passive pixel array sensor. 14. A system for measuring range and optically forming an object, comprising: (a) a first light source arranged at a certain distance from said object and operative to illuminate said object; (b) a second light source disposed at a distance from said object that is virtually different from said certain distance and operative to illuminate said object; 25 (c) operable means to energize alternately said first and second sources; (d) a plurality of photo-detectors and means for focusing reflected light from said object on said detectors, each operating detector for providing an electrical signal indicative of 5 the intensity of the light received in it; (e) operating means for storing the values of said signal for each detector for each illumination; (f) operating means for calculating the ratio of said values of said signal for illumination by said sources 10 first and second for each detector; (g) operating means for calculating the distance of the object from each of said detectors for each of said calculated signal ratios; and (h) operating means for mapping said calculated distances and forming images of said object. The system defined in claim 14, wherein said first and second sources emit light in the visible spectrum. 16. The system defined in claim 14, wherein said first and second sources emit light in the infrared spectrum. The system defined in claim 14, wherein said first and second sources emit light in the range of about 350 to 14,000 nanometers wavelength. 18. The system defined in claim 14, wherein ^? This arrangement of photo-detectors comprises pixels in a solid-state silicon device. The system defined in claim 14, wherein said array of photo-detectors comprises pixels in a CMOS solid state device. The system defined in claim 14, wherein said operating means for storing include an analog-to-digital converter. The system defined in claim 14, wherein said second light source has a lens disposed between said second source and said object for effecting said virtual distance different from said certain distance. 22. The system defined in claim 14, wherein said array of detectors is disposed between said first and second sources. 2
3. 3. The system defined in claim 14, wherein said first and second sources comprise light emitting diodes. The system defined in claim 14, wherein said operating means for calculating the ratio includes operable means for removing the effects on said signals from the ambient light on said detectors. 25. A system for determining the presence and position of the occupant of a seat in a vehicle and providing an electrical indication thereof, comprising: (a) a first source of light disposed in said vehicle at a certain distance from said seat and operative to illuminate said seat and an occupant therein; (b) a second light source disposed at a distance 5 from said seat virtually different from said certain distance and operative to illuminate said seat and occupant; (c) a plurality of photo-detectors arranged to receive, each, reflected light from said occupant and operative to generate an electrical signal indicative of the intensity of 10 said received light; (d) operable means for alternately energizing said first and second sources; (e) operating means for storing the values of said signal generated from each detector for each illumination; 15 (f) operating means for calculating the ratio of said stored values of said signals for illumination of said first and second sources for each detector; (g) operating means for calculating said distance of the occupant from each of said detectors for each of said calculated signal ratios; and (h) operating means for mapping said calculated and operating distances to provide said electrical indication of the presence of the occupant and an image of said position. 26. The system defined in claim 25, wherein said second light source includes means that form an image. virtual of said second source, said means selected from the group consisting of a lens and a mirror. 27. A method for determining the presence and position of the occupant of a seat in a vehicle and providing an electrical image thereof, comprising: 28. The method defined in claim 27, further comprising generating a suppression signal when said image shows a position of the occupant out of tolerance and applies said suppression signal to prevent energization of an airbag inflator. 29. The method defined in claim 27, wherein said step of storing sequentially includes converting from analog to digital. 30. A system for measuring the optical range of an object, comprising: (a) at least one photo-detector arranged to receive light reflected from said object and operable to generate an electrical indication of the intensity of said received light; (b) a first light source disposed at a certain distance from said object and operable upon energization to illuminate said object) a second source of light disposed at a virtually different distance from said certain distance from said object and operable upon energization for illuminate said object; l I I l I I I - I II i i • 1 (d) operable means for storing the value of said electrical indication for each illustration of said object by said first and second light sources; and (e) operable means to calculate the ratio of said stored values of said electrical indication and operable to calculate the range of said objective from said relation. 31. The system defined in claim 30, wherein said at least one photo-detector includes a plurality of photo-detectors. 32. The system defined in claim 30, wherein said first and second light sources emit light selected from the group consisting of wavelengths in the range of about 350 to 14,000 nanometers. 33. A method of measuring the range and optically shaping an object, comprising: (a) arranging a plurality of photo-detectors to receive the reflected light from said object and generating an electrical signal indicative of the intensity of the received light; (b) providing a light source and directing and framing the light of said source to said object alternately from a real source and a virtual source at a significantly different distance from said object than said actual source; (c) storing values of said electrical signal for each photo-detector of said plurality of photo-detectors; g ^ ^ ^ ¿»H UiMi.i.?.11 (d) calculate the relationship of these values for sets of real and virtual tables and calculate the object range for each relation; (e) mapping the calculated object ranges for each photo-detector of said plurality of photo-detectors and forming images of said object. 3
4. 4. The method defined in claim 33, wherein said framing step includes obturating. 3
5. 5. The method defined in claim 33, wherein said step of stepping alternately includes reflecting light from a mirror. 3
6. 6. The method defined in claim 33, wherein said stepping step alternately includes passing light through a lens. 3
7. 7. The method defined in claim 33, wherein said step of framing includes rotating a shutter.