초록 ▼

The distance and external contour of objects are imaged using time domain measurement. An array of pixel cells receives a time-varying waveform (e.g., a ramp voltage) time synchronized to a transmitted light pulse. Each pixel cell senses light from the pulse that is reflected from objects in the fie

The distance and external contour of objects are imaged using time domain measurement. An array of pixel cells receives a time-varying waveform (e.g., a ramp voltage) time synchronized to a transmitted light pulse. Each pixel cell senses light from the pulse that is reflected from objects in the field of view of the apparatus, and stores the value of the ramp voltage at the time the reflected light pulse is detected at that pixel cell. The ramp voltage at any time is known and therefore serves as a measure of the combined transmission and reflection times of the light pulse for each pixel cell. The speed of light is also known, therefore the stored voltage level at each pixel cell represents the distance between the apparatus of a portion of the object from which the light pulse is reflected. The stored pixel cell voltages can be delivered sequentially to a monochrome video monitor pursuant per any suitable video standard. The imaging technique of the present invention does not record or display the intensity of the reflected and received light; instead, the invention provides an output signal that is an x-y representation of the distance of the distance of viewed objects from the sensor pixel cells. The resulting scene on the display represents distances and external shapes of viewed objects, not patterns, shadings or textures.

대표청구항 ▼

1. A method for imaging objects located within a predetermined range from a sensor having multiple individual energy wave detectors disposed in a predetermined array, said method comprising the steps of:(a) transmitting a pulse Of said energy in the general direction of said objects; (b) in time syn

1. A method for imaging objects located within a predetermined range from a sensor having multiple individual energy wave detectors disposed in a predetermined array, said method comprising the steps of:(a) transmitting a pulse Of said energy in the general direction of said objects; (b) in time synchronization with transmission of said energy pulse in step (a), initiating a global time-varying measurement signal having a predetermined duration and a specified parameter with a value that both varies with time and is non-repetitive throughout said predetermined duration; (c) receiving respective reflections of said energy pulse from said objects at detectors in said array; (d) at each detector, storing the value of said global measurement signal parameter at the time of reception of said reflection in step (c); and (e) representing said objects as a function of the parameter values stored at said detectors. 2. The method of claim 1 wherein step (e) comprises generating an output signal with a waveform corresponding to the stored measurement parameter values at each detector arranged in a predetermined sequence related to the positions of the detectors in said array.3. The method of claim 1 wherein said array is a generally rectangular array of rows and columns of said detectors and wherein said predetermined sequence is the row by row positioning of said detectors in said array.4. The method of claim 1 wherein step (a) comprises transmitting a pulse of light energy having a known frequency, wherein said detectors are photodetectors responsive to light energy at said known frequency.5. The method of claim 4 wherein said global measurement signal is a ramp voltage with a voltage amplitude that varies linearly with time throughout said predetermined duration; andwherein step (e) comprises representing said objects in a visibly perceptible format. 6. The method of claim 5 wherein said detectors are arranged in a rectangular array of columns and rows, each detector corresponding to a pixel of light energy received in step (c).7. The method of claim 1 wherein step (b) comprises generating said global measurement signal as a time varying voltage signal, and wherein said specified parameter is the amplitude of the voltage signal.8. The method of claim 7 wherein said voltage signal is a ramp function with a voltage amplitude that varies linearly with time throughout said predetermined duration.9. Apparatus for imaging objects located within a predetermined range, comprising:a sensor having multiple individual energy wave detectors disposed in a predetermined array; a transmitter for transmitting a pulse of said energy in the general direction of said objects; a measurement signal generator for generating a global time-varying measurement signal in time synchronization with transmission of said energy pulse by said transmitter, said global time-varying measurement signal having a predetermined duration and a specified parameter with a value that both varies with time and is non-repetitive throughout said predetermined duration; wherein said multiple detectors receive respective reflections of said energy pulse from said objects as a function of the position of the detectors in said array relative to the object; at each detector, a storage circuit for storing the value of said global measurement signal parameter at the time of reception of said reflection by that detector; and output means for providing an output signal having a waveform corresponding to the stored values of said measurement signal parameter at said multiple detectors. 10. The apparatus of claim 9 wherein said transmitter comprises a transmitter of a pulse of light energy having a known frequency, wherein said detectors are photodetectors responsive to light energy at said known frequency.11. The apparatus of claim 10 wherein said global measurement signal is a ramp voltage with a voltage amplitude that varies linearly with time throughout said predetermined duration; and further comprising means responsive to said output signal for representing said objects in a visibly perceptible format.12. The apparatus of claim 11 wherein said detectors are arranged in a rectangular array of columns and rows, each detector corresponding to a pixel of light energy received by said photodetectors.13. The apparatus of claim 9 wherein said measurement signal generator includes means for generating said global measurement signal as a time varying voltage signal, and wherein said specified parameter is the amplitude of the voltage signal.14. The apparatus of claim 13 wherein said voltage signal is a ramp function with a voltage amplitude that varies linearly with time throughout said predetermined duration.15. A time of flight measurement system used with a generator outputting at least a first light pulse to determine a distance between said system and a target within a system field of view comprising:an array of pixel detectors optically enveloping said system field of view, wherein said pixel detectors detect, in parallel, generated light pulse energy returned from said target; for each of said pixel detectors, an associated charge collector to collect charge in accordance with detected optical energy reflected from said target resulting from said first pulse, wherein each pixel detector is associated with a different charge collector, and for each pixel detector an associated trigger coupled to said charge collector associated with that pixel detector to control ability of said associated charge collector to collect charge; and an evaluation unit for evaluating accumulated charge accumulated in each said collector to obtain a measure of actual time of flight for each said pixel detector to said target; wherein said distance to said target may be determined. 16. The system of claim 15, further including:a measurement signal generator for generating a time-varying measurement signal in time synchronization with transmission of said first pulse, said time varying measurement signal having a predetermined duration and a specified parameter with a value that both varies with time and is non-repetitive throughout said predetermined duration, wherein said measurement signal is supplied to each said charge collector to enable said charge collector to accumulate charge. 17. The system of claim 16, wherein said measurement signal generator includes means for generating said measurement signal as a time varying voltage signal, and wherein said specified parameter is the amplitude of the voltage signal.18. The system of claim 17, wherein said voltage signal is a ramp function with a voltage amplitude that varies linearly with time throughout said predetermined duration.19. A method to determine a distance between a detector array and a target within a field of view comprising the steps of:(a) disposing said array so as to detect optical energy reflected from said target, the array comprising a plurality of pixel detectors optically enveloping said field of view and detecting, in parallel, said reflected optical energy, and for each pixel detector providing an associated charge collector, wherein each pixel detector is associated with a different charge collector, and for each pixel detector an associated trigger coupled to said charge collector associated with that pixel detector to control ability of said associated charge collector to collect charge; (b) illuminating said target with a first pulse of optical energy and enabling each said charge collector to collect charge in accordance with detected optical energy reflected from said target resulting from said pulse; (c) beginning at said target illumination to accumulate charge in each said collector; (d) disabling each said associated collector from accumulating further charge via an associated trigger; and (e) evaluating charge accumulated in each said collector to obtain a measure of actual time of flight for each said pixel detector to said target; wherein said distance to said target may be determined. 20. The method of claim 19, wherein step (c) further includes:(c.1) in time synchronization with transmission of said first pulse of optical energy, initiating a time-varying measurement signal having a predetermined duration and a specified parameter with a value that both varies with time and is non-repetitive throughout said predetermined duration, wherein said measurement signal is supplied to each said charge collector to enable said charge collector to accumulate charge. 21. The method of claim 20, wherein step (c.1) further includes:(c.1.1) generating said measurement signal as a time varying voltage signal, and wherein said specified parameter is the amplitude of the voltage signal. 22. The method of claim 21, wherein said voltage signal is a ramp function with a voltage amplitude that varies linearly with time throughout said predetermined duration.