US5371361A — Optical processing system

Claim 1

Independent Claim 159 words

A scanner comprising: an opto-mechanical system for providing a moving beam of light having a beam axis, directing said beam along an outgoing optical path toward a target situated within a scan volume, and scanning said beam over the target in a predetermined pattern; a collection system for collecting light reflected from or scattered off the target, the collected light having a given intensity; and an electrical system operatively coupled to said collection system for forming a signal having an amplitude at least partly determined by the given intensity of the collected light; wherein said opto-mechanical system is configured to direct said beam into the scan volume such that at least one parameter associated with said opto-mechanical system, which would otherwise vary over the scan volume, remains approximately constant along the beam axis within the scan volume, thereby improving the capability of said electrical system to properly compensate for unwanted variations in the amplitude modulation depth of said signal.

Claim 2

Dependent Claim 159 words

A scanner comprising: an opto-mechanical system for providing a moving beam of light having a beam axis, directing said beam along an outgoing optical path toward a target situated within a scan volume, and scanning said beam over the target in a predetermined pattern; a collection system for collecting light reflected from or scattered off the target, the collected light having a given intensity; and an electrical system operatively coupled to said collection system for forming a signal having an amplitude at least partly determined by the given intensity of the collected light; wherein said opto-mechanical system is configured to direct said beam into the scan volume such that at least one parameter associated with said opto-mechanical system, which would otherwise vary over the scan volume, remains approximately constant along the beam axis within the scan volume, thereby improving the capability of said electrical system to properly compensate for unwanted variations in the amplitude modulation depth of said signal.

Claim 3

Dependent Claim 14 words

The scanner of claim 1 wherein said beam of light comprises a laser beam.

Claim 4

Dependent Claim 46 words

The scanner of claim 1 wherein said opto-mechanical system has a time domain impulse response width, and is configured such that said time domain impulse response width of said opto-mechanical system is the parameter which remains approximately constant along the beam axis within the scan volume.

Claim 5

Dependent Claim 49 words

The scanner of claim 3 wherein said opto-mechanical system is configured to produce a beam waist along said optical path, and to position said beam waist such that said time domain impulse response width of the opto-mechanical system remains approximately constant along the beam axis within the scan volume.

Claim 6

Dependent Claim 40 words

The scanner of claim 4 wherein said opto-mechanical system has a scanning mirror with an optical center of rotation, and said opto-mechanical system is configured to position said beam waist at said optical center of rotation of said scanning mirror.

Claim 7

Dependent Claim 46 words

The scanner of claim 4 wherein said opto-mechanical system has a scanning mirror with a center of rotation, and said opto-mechanical system is configured to position said beam waist at a position between said optical center of rotation of said scanning mirror and the scanner window.

Claim 8

Dependent Claim 22 words

The scanner of claim 6 wherein said opto-mechanical system is configured to position said beam waist at the window of the scanner.

Claim 9

Dependent Claim 27 words

The scanner of claim 7 wherein said opto-mechanical system is configured to position said beam waist within 1/2 inch (1.27 cm) of the window of the scanner.

Claim 10

Dependent Claim 54 words

The scanner of claim 3 wherein said beam, in cross-section, has a spot size, and is directed to move at a linear spot velocity, and said opto-mechanical system is configured such that said spot velocity and said spot size of said beam both increase approximately linearly along the beam axis within the scan volume.

Claim 11

Dependent Claim 30 words

The scanner of claim 3 wherein said time domain impulse response width is maintained throughout the scan volume to within ±25% of its value at a window of the scanner.

Claim 12

Dependent Claim 30 words

The scanner of claim 3 wherein said time domain impulse response width is maintained throughout the scan volume to within ±10% of its value at a window of the scanner.

Claim 13

Dependent Claim 61 words

The scanner of claim 1 wherein said beam, in cross-section, has a spot size and is directed to move at a linear spot velocity, and said opto-mechanical system is configured such that said parameter which remains approximately constant along the beam axis within the scan volume is the ratio of the spot size of the beam to the linear spot velocity.

Claim 14

Dependent Claim 36 words

The scanner of claim 12 wherein the ratio of said spot size of the beam to the linear spot velocity is maintained to a value within ±25% of its value at a window of the scanner.

Claim 15

Dependent Claim 48 words

The scanner of claim 1 wherein the parameter which remains approximately constant along the beam axis within the scan volume is selected from the group consisting of time domain impulse response width, ratio of said spot size of the beam to the linear spot velocity, and beam power.

Claim 16

Dependent Claim 68 words

The scanner of claim 1 wherein the opto-mechanical system includes a rotating scan mirror and control means for controlling rotational velocity of the rotating scan mirror, said control means adjusting the velocity of the rotating scan mirror to correspond to a given linear spot velocity at any distance between the scanner and the target within the scan volume to maintain approximately constant linear spot velocity on the target.

Claim 17

Dependent Claim 21 words

The scanner of claim 15 wherein said opto-mechanical system further comprises means for holding spot size constant over the scan volume.

Claim 18

Dependent Claim 36 words

The scanner of claim 15 wherein said opto-mechanical system includes an optical element positioned in the outgoing optical path to maintain spot size of said beam approximately constant along the beam axis within the scan volume.

Claim 19

Dependent Claim 12 words

The scanner of claim 17 wherein said optical element is an axicon.

Claim 20

Dependent Claim 31 words

The scanner of claim 1 wherein said electrical system is further configured to equalize the signal for unwanted variations in amplitude modulation depth along the beam axis within the scan volume.

Claim 21

Dependent Claim 32 words

The scanner of claim 19 wherein said electrical system is further configured to equalize the signal in such a way that variation in group delay response over the spectral passband is minimized.

Claim 22

Dependent Claim 137 words

A scanner comprising: an opto-mechanical system for providing a moving beam of light having a beam axis, directing said beam along an outgoing optical path toward a target situated within a scan volume, and scanning said beam over the target in a predetermined pattern, said opto-mechanical system being configured to have an impulse response which is approximately constant within the scan volume; a collection system for collecting light reflected from or scattered off the target, the collected light having a given intensity; and an electrical system operatively coupled to said collection system for producing a signal having an amplitude determined at least partly by the intensity of the collected light, said electrical system including a filter configured to limit the spectral response of said signal, said filter having approximately constant group delay over the filter spectral passband.

Claim 23

Dependent Claim 137 words

A scanner comprising: an opto-mechanical system for providing a moving beam of light having a beam axis, directing said beam along an outgoing optical path toward a target situated within a scan volume, and scanning said beam over the target in a predetermined pattern, said opto-mechanical system being configured to have an impulse response which is approximately constant within the scan volume; a collection system for collecting light reflected from or scattered off the target, the collected light having a given intensity; and an electrical system operatively coupled to said collection system for producing a signal having an amplitude determined at least partly by the intensity of the collected light, said electrical system including a filter configured to limit the spectral response of said signal, said filter having approximately constant group delay over the filter spectral passband.

Claim 24

Dependent Claim 26 words

The scanner of claim 21 wherein a maximum value of the group delay is held to within 15% over its minimum value through the scan volume.

Claim 25

Dependent Claim 27 words

The scanner of claim 21 wherein the maximum value of the group delay is held to within about 6-8% over its minimum value through the scan volume.

Claim 26

Dependent Claim 35 words

The scanner of claim 21 wherein said electrical system is further configured to equalize said signal for unwanted variations in amplitude modulation depth and/or group delay response along the beam axis within the scan volume.

Claim 27

Dependent Claim 228 words

A scanner comprising: an opto-mechanical system for providing a moving beam of light having a beam axis, directing said beam along an outgoing optical path toward a target situated within a scan volume, and scanning said beam over the target in a predetermined pattern; a collection system for collecting light reflected from or scattered off the target, the collected light having a given intensity; and an electrical system operatively coupled to said collection system for producing a signal having an amplitude determined at least partly by the intensity of the collected light, said electrical system including a filter configured to limit the spectral response of said signal, said electrical system being further configured to equalize said signal for unwanted variations in amplitude modulation depth and/or group delay response along the beam axis within the scan volume, said filter having approximately constant group delay over the filter spectral passband and said filter further comprising an equalizing signal processing subsystem which includes a low pass filter having an output, a high pass filter in parallel with said low pass filter and also having an output, and a summation stage having at least two inputs, wherein said output of said low pass filter is coupled to a first input of said summation stage, and said output of said high pass filter is coupled to a second input of said summation stage.

Claim 28

Dependent Claim 228 words

A scanner comprising: an opto-mechanical system for providing a moving beam of light having a beam axis, directing said beam along an outgoing optical path toward a target situated within a scan volume, and scanning said beam over the target in a predetermined pattern; a collection system for collecting light reflected from or scattered off the target, the collected light having a given intensity; and an electrical system operatively coupled to said collection system for producing a signal having an amplitude determined at least partly by the intensity of the collected light, said electrical system including a filter configured to limit the spectral response of said signal, said electrical system being further configured to equalize said signal for unwanted variations in amplitude modulation depth and/or group delay response along the beam axis within the scan volume, said filter having approximately constant group delay over the filter spectral passband and said filter further comprising an equalizing signal processing subsystem which includes a low pass filter having an output, a high pass filter in parallel with said low pass filter and also having an output, and a summation stage having at least two inputs, wherein said output of said low pass filter is coupled to a first input of said summation stage, and said output of said high pass filter is coupled to a second input of said summation stage.

Claim 29

Dependent Claim 18 words

The scanner of claim 25 wherein said first and second inputs of said summation stage have opposite polarity.

Claim 30

Dependent Claim 15 words

The scanner of claim 21 wherein said filter is of the transitional-Gaussian family of filters.

Claim 31

Dependent Claim 48 words

The scanner of claim 21 wherein said filter is selected from the group consisting of: a transversal filter, a tapped-delay line filter, a finite impulse response digital filter, a Bessel filter, a Linear Phase with Equiripple Error filter, a delay-equalized filter, a matched filter, and a correlation filter.

Claim 32

Independent Claim 94 words

A method for scanning a target comprising the steps of: locating a target within a desired scan volume; providing a beam having a beam axis; directing said beam along an outgoing optical path toward the target; scanning said beam over the target in a predetermined pattern; collecting light reflected from or scattered off the target, the collected light having an intensity; forming a signal having an amplitude determined, at least in part, by the intensity of the collected light; and improving the capability of equalizing said signal for unwanted variations in amplitude modulation depth.

Claim 33

Independent Claim 94 words

A method for scanning a target comprising the steps of: locating a target within a desired scan volume; providing a beam having a beam axis; directing said beam along an outgoing optical path toward the target; scanning said beam over the target in a predetermined pattern; collecting light reflected from or scattered off the target, the collected light having an intensity; forming a signal having an amplitude determined, at least in part, by the intensity of the collected light; and improving the capability of equalizing said signal for unwanted variations in amplitude modulation depth.

Claim 34

Dependent Claim 53 words

The method of claim 29 further comprising the steps of: holding at least one parameter, which would otherwise vary along the beam axis within the scan volume, approximately constant over the scan volume, thereby improving the equalizing capability; and equalizing said signal, at least in part, for unwanted variations in amplitude modulation depth.

Claim 35

Dependent Claim 43 words

The method of claim 30 further comprising: producing a beam waist along said optical path; and positioning said beam waist such that the time domain impulse response width is said parameter being held approximately constant along the beam axis within the scan volume.

Claim 36

Dependent Claim 24 words

The method of claim 30 wherein said parameter which is held approximately constant is the time domain impulse response width of said opto-mechanical system.

Claim 37

Dependent Claim 48 words

The method of claim 32 wherein said beam provided has, in cross-section, a spot size, and said beam is scanned over the target at a linear spot velocity, further comprising: approximately linearly increasing said linear spot velocity and said spot size of said beam over the scan volume.

Claim 38

Dependent Claim 54 words

The method of claim 29 wherein said beam has, in cross-section, a spot size, and said beam is scanned over the target at a linear spot velocity, further comprising: holding the ratio of said spot size of said beam to said linear spot velocity approximately constant along the beam axis within the scan volume.

Claim 39

Dependent Claim 51 words

The method of claim 29 wherein said beam has, in cross-section, a spot size, and said beam is scanned over the target at a linear spot velocity, further comprising: holding said linear spot velocity and said spot size of said beam approximately constant along the beam axis within the scan volume.

Claim 40

Dependent Claim 13 words

The method of claim 29 wherein said beam provided is a laser beam.

Claim 41

Independent Claim 90 words

A method for scanning a target comprising: locating a target within a desired scan volume; providing a beam having a beam axis; directing said beam along an optical path to the target; scanning said beam over the target in a predetermined pattern; collecting light reflected from or scattered off the target, the collected light having an intensity; producing a signal having an amplitude determined at least partly by the intensity of the collected light; and band-limiting said signal with a filter exhibiting approximately constant group delay response within its passband.

Claim 42

Independent Claim 90 words

A method for scanning a target comprising: locating a target within a desired scan volume; providing a beam having a beam axis; directing said beam along an optical path to the target; scanning said beam over the target in a predetermined pattern; collecting light reflected from or scattered off the target, the collected light having an intensity; producing a signal having an amplitude determined at least partly by the intensity of the collected light; and band-limiting said signal with a filter exhibiting approximately constant group delay response within its passband.

Claim 43

Dependent Claim 29 words

The method of claim 37 further comprising: equalizing said signal, at least in part, for unwanted variations in amplitude modulation depth along the beam axis within the scan volume.

Claim 44

Dependent Claim 163 words

A scanner comprising: an opto-mechanical system for providing a beam having a beam axis, directing said beam along an optical path to a target situated within a desired scan volume, and scanning said beam over the target in a predetermined pattern, wherein said beam in cross-section, has a spot size, and said opto-mechanical system is configured to increase said spot size of said beam such that depth of focus is increased and the effects of noise on the target are averaged out; a collection system for collecting light reflected from or scattered off the target, the collected light having an intensity; and an electrical system operatively coupled to said collection system for producing a signal having an amplitude determined at least partly by the intensity of the collected light and for equalizing said signal, at least in part, for unwanted variations in the amplitude modulation depth of said signal caused by the increased spot size along the beam axis within the scan volume.

Claim 45

Dependent Claim 163 words

A scanner comprising: an opto-mechanical system for providing a beam having a beam axis, directing said beam along an optical path to a target situated within a desired scan volume, and scanning said beam over the target in a predetermined pattern, wherein said beam in cross-section, has a spot size, and said opto-mechanical system is configured to increase said spot size of said beam such that depth of focus is increased and the effects of noise on the target are averaged out; a collection system for collecting light reflected from or scattered off the target, the collected light having an intensity; and an electrical system operatively coupled to said collection system for producing a signal having an amplitude determined at least partly by the intensity of the collected light and for equalizing said signal, at least in part, for unwanted variations in the amplitude modulation depth of said signal caused by the increased spot size along the beam axis within the scan volume.

Claim 46

Independent Claim 121 words

A method for scanning a target comprising: locating a target within a desired scan volume; providing a beam which has a beam axis, and, in cross-section, a spot size; directing said beam along an optical path to the target; scanning said beam over the target in a predetermined pattern; increasing said spot size of said beam to average out the effects of target noise; collecting light reflected from or scattered off the target, the collected light having an intensity; producing a signal having an amplitude determined at least partly by the intensity of the collected light; and equalizing said signal, at least in part, for unwanted variations in the amplitude modulation depth of said signal caused by the increased spot size.

Claim 47

Independent Claim 121 words

A method for scanning a target comprising: locating a target within a desired scan volume; providing a beam which has a beam axis, and, in cross-section, a spot size; directing said beam along an optical path to the target; scanning said beam over the target in a predetermined pattern; increasing said spot size of said beam to average out the effects of target noise; collecting light reflected from or scattered off the target, the collected light having an intensity; producing a signal having an amplitude determined at least partly by the intensity of the collected light; and equalizing said signal, at least in part, for unwanted variations in the amplitude modulation depth of said signal caused by the increased spot size.

Claim 48

Dependent Claim 76 words

A scanner comprising: an electro-optical system for capturing an image of a target situated within a desired scan volume and providing a signal having an amplitude determined at least partly by the intensity of said image; wherein said electro-optical system includes an optical element to introduce an aberration into said image, thereby improving the capability of said electro-optical system to compensate for unwanted variations in the amplitude modulation depth of said signal over the scan volume.

Claim 49

Dependent Claim 76 words

A scanner comprising: an electro-optical system for capturing an image of a target situated within a desired scan volume and providing a signal having an amplitude determined at least partly by the intensity of said image; wherein said electro-optical system includes an optical element to introduce an aberration into said image, thereby improving the capability of said electro-optical system to compensate for unwanted variations in the amplitude modulation depth of said signal over the scan volume.

Claim 50

Dependent Claim 16 words

The scanner of claim 41 wherein said electro-optical system is configured to capture a one-dimensional image.

Claim 51

Dependent Claim 16 words

The scanner of claim 41 wherein said electro-optical system is configured to capture a two-dimensional image.

Claim 52

Dependent Claim 19 words

The scanner of claim 41 wherein said optical element is configured to introduce a spherical aberration into said image.

Claim 53

Dependent Claim 13 words

The scanner of claim 41 wherein said optical element is a soft-focus lens.

Claim 54

Dependent Claim 12 words

The scanner of claim 41 wherein said optical element is an axicon.

Claim 55

Dependent Claim 28 words

The scanner of claim 41 wherein said optical element is configured to introduce a chromatic aberration into said image, and wherein the target is illuminated with polychromatic light.

Claim 56

Dependent Claim 29 words

The scanner of claim 41 wherein said electro-optical system is further configured to compensate for unwanted variations in the amplitude modulation depth of said signal over the scan volume.

Claim 57

Dependent Claim 16 words

The scanner of claim 41 wherein said electro-optical system includes a CCD for capturing said image.

Claim 58

Dependent Claim 17 words

The scanner of claim 41 wherein said electro-optical system includes a video camera for capturing said image.

Claim 59

Dependent Claim 49 words

The scanner of claim 41 wherein said electro-optical system includes a CCD-like imaging device comprising an array of photodetectors, for capturing and representing said image in pixels, and wherein said pixels are individually addressable, providing for sensing of said image by reading out said pixels in a predetermined pattern.

Claim 60

Independent Claim 63 words

A method for scanning a target comprising: scanning an image of a target situated within a desired scan volume; producing a signal having an amplitude determined at least partly by the intensity of said image; and improving the capability for equalizing for variations in the amplitude modulation depth of said signal over the scan volume by introducing an optical aberration into said image.

Claim 61

Independent Claim 63 words

A method for scanning a target comprising: scanning an image of a target situated within a desired scan volume; producing a signal having an amplitude determined at least partly by the intensity of said image; and improving the capability for equalizing for variations in the amplitude modulation depth of said signal over the scan volume by introducing an optical aberration into said image.

Claim 62

Dependent Claim 14 words

The method of claim 52 further comprising capturing a one-dimensional image of the target.

Claim 63

Dependent Claim 14 words

The method of claim 52 further comprising capturing a two-dimensional image of the target.

Claim 64

Dependent Claim 14 words

The method of claim 52 further comprising introducing a spherical aberration into said image.

Claim 65

Dependent Claim 14 words

The method of claim 52 further comprising introducing a chromatic aberration into said image.

Claim 66

Dependent Claim 29 words

The method of claim 52 further comprising: equalizing said signal, at least in part, for unwanted variations in the amplitude modulation depth of said signal over the scan volume.

Claim 67

Dependent Claim 125 words

A scanner comprising: an opto-mechanical system for providing a beam, directing said beam along an optical path to a target situated within a desired scan volume, and scanning said beam over the target in a predetermined pattern; wherein said beam has a power which otherwise varies as said beam is scanned over the target in said predetermined pattern, and said system includes a beam power control means for holding power of said beam approximately constant within the scan volume over said pattern; a collection system for collecting light from the target, the collected light having an intensity; and an electrical system operatively coupled to said collection system for forming a signal having an amplitude determined at least partly from the intensity of the collected light.

Claim 68

Dependent Claim 125 words

A scanner comprising: an opto-mechanical system for providing a beam, directing said beam along an optical path to a target situated within a desired scan volume, and scanning said beam over the target in a predetermined pattern; wherein said beam has a power which otherwise varies as said beam is scanned over the target in said predetermined pattern, and said system includes a beam power control means for holding power of said beam approximately constant within the scan volume over said pattern; a collection system for collecting light from the target, the collected light having an intensity; and an electrical system operatively coupled to said collection system for forming a signal having an amplitude determined at least partly from the intensity of the collected light.

Claim 69

Dependent Claim 35 words

The scanner of claim 58 wherein said electrical system is configured with a reduced dynamic range than otherwise would be required if said power of said beam were not held approximately constant over said pattern.

Claim 70

Dependent Claim 99 words

The scanner of claim 58 wherein said opto-mechanical system further comprises: a rotating scanning mirror, with one or more reflective segments around its periphery, having an angular position with respect to an origin; and, a wheel, having a periphery which is mounted in the path of said outgoing beam, cooperative with said rotating scanning mirror, in which the transmissivity of said wheel periphery varies with the angular position of said scanning mirror in such a way as to cause said power of said outgoing beam, as measured in the scan volume, to remain approximately constant regardless of beam position.

Claim 71

Dependent Claim 83 words

The scanner of claim 58 wherein said opto-mechanical system further comprises: a rotating scanning mirror, with one or more reflective segments around its periphery, having an angular position with respect to an origin which varies as said mirror rotates; a laser for providing said beam; and means for producing a driving signal for said laser which varies according to said angular position of said scanning mirror, in such a way as to maintain said power of said beam approximately constant over said pattern.

Claim 72

Dependent Claim 114 words

The scanner of claim 61 wherein said producing means comprises: an optical encoding wheel cooperative with said rotating scanning mirror, having on its periphery an identification means identifying one to n--where n is the number of pattern repetitions per rotation--angular positions of said rotating scanning mirror; means for converting said identification means into electrical pulses which indicate said angular position of said scanning mirror; means for multiplying the rate of said electrical pulses; means for producing a digital signal having a value related to said angular position of said scanning mirror; and a look-up table coupled to and addressable by said digital signal for identifying an appropriate value for use as said driving signal.

Claim 73

Dependent Claim 14 words

The scanner of claim 62 wherein said identification means comprises at least one mark.

Claim 74

Dependent Claim 14 words

The scanner of claim 62 wherein said identification means comprises at least one hole.

Claim 75

Dependent Claim 19 words

The scanner of claim 62 wherein said digital signal is produced from a clock generated by said multiplying means.

Claim 76

Dependent Claim 47 words

The scanner of claim 61 wherein said producing means comprises: an optical encoding wheel, cooperative with said rotating scanning mirror, having, on its periphery, identification means associated with any given angular position of said scanning mirror; and means for converting said identification means into said driving signal.

Claim 77

Dependent Claim 14 words

The scanner of claim 66 wherein said identification means comprises at least one mark.

Claim 78

Dependent Claim 14 words

The scanner of claim 66 wherein said identification means comprises at least one hole.

Claim 79

Independent Claim 99 words

A method for scanning a target comprising: locating a target within a scan volume; providing a beam having a beam axis; directing said beam along an optical path to the target; scanning said beam over the target in a predetermined pattern, wherein said beam has a power; holding said power of said beam within the scan volume, which would otherwise vary, approximately constant over said pattern; collecting light reflected from or scattered off the target, the collected light having an intensity; and forming a signal having an amplitude determined at least partly from the intensity of the collected light.

Claim 80

Independent Claim 99 words

A method for scanning a target comprising: locating a target within a scan volume; providing a beam having a beam axis; directing said beam along an optical path to the target; scanning said beam over the target in a predetermined pattern, wherein said beam has a power; holding said power of said beam within the scan volume, which would otherwise vary, approximately constant over said pattern; collecting light reflected from or scattered off the target, the collected light having an intensity; and forming a signal having an amplitude determined at least partly from the intensity of the collected light.

Claim 81

Dependent Claim 49 words

The method of claim 69 wherein said signal is formed by an electrical system having a dynamic range, further comprising the step of: reducing said dynamic range from a level that would otherwise be required if said power of said beam were not held approximately constant over said pattern.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1997-12-05	1998-06-06	1998-12-06	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	2001-12-05	2002-06-06	2002-12-06	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	2005-12-05	2006-06-06	2006-12-06	$7700.00	Window Closed / Lapsed

Optical processing system

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