Holographic display apparatus and method

Abstract

The present invention relates generally to an optical element (OE) which can serve as an optical analogue to digital converter (OADC) and/or an optical digital to analogue converter (ODAC), and uses therefor. The OE can be usefully employed in a variety of applications to transform analogue information present in a light wave front into digital light signals and/or to transform digital information into analogue information in the form of the physical parameters of a light wave front.

1 . An optical element having the capacity to transform information contained in a light wave front into a 1D, 2D or 3D array of light signals and/or to transform the information contained in a 1D, 2D or 3D array of light signals into a light wave front.  
     
     
         2 . The optical element of  claim 1  wherein the information contained in the light wave front is contained in the radius of curvature of the light wave front.  
     
     
         3 . The optical element of  claim 1  wherein the information contained in the light wave front is contained in the direction vector of the light wave front.  
     
     
         4 . The optical element of  claim 1  wherein the information contained in the light wave front is contained in both the radius of curvature and the direction vector of the light wave front.  
     
     
         5 . The optical element of  claim 1  wherein the information contained in the light wave front is not contained in the intensity of the light wave.  
     
     
         6 . The optical element of  claim 1  wherein the optical element is a hologram.  
     
     
         7 . The optical element of  claim 1  wherein the optical element is an imposed hologram.  
     
     
         8 . The optical element of  claim 1  wherein the optical element is an imposed hologram which has been recorded using a series of masks with apertures corresponding to the codes to be generated by the hologram.  
     
     
         9 . The optical element of  claim 1  wherein the optical element is a computer generated hologram.  
     
     
         10 . The optical element of  claim 1  wherein the optical element is a kinoform.  
     
     
         11 . The optical element of  claim 1  wherein the optical element is a spatial light modulator.  
     
     
         12 . The optical element of  claim 1  wherein the signals are in the form of light shapes.  
     
     
         13 . The optical element of  claim 12  wherein the light shapes are spots.  
     
     
         14 . The optical element of  claim 1  wherein the array of light signals is one of a set of all possible codes of a binary code system.  
     
     
         15 . The optical element of  claim 14  wherein the binary code has 1-100 binary digits.  
     
     
         16 . The optical element of  claim 14  wherein the binary code has 1-50 binary digits.  
     
     
         17 . The optical element of  claim 14  wherein the binary code has 1-20 binary digits.  
     
     
         18 . The optical element of  claim 14  wherein the binary code is a hexadecimal code.  
     
     
         19 . The optical element of  claim 14  wherein the binary code is a 1D code.  
     
     
         20 . The optical element of  claim 14  wherein the binary code is a 2D code.  
     
     
         21 . The optical element of  claim 14  wherein the binary code is a 3D code.  
     
     
         22 . An optical analogue-to-digital converter comprising: 
 (a) a light source for directing light to the optical element;    (b) an optical element positioned in a receiving relationship to light emitted from the light source and having the capacity to transform information contained in a light wave front of the emitted light into a 1D, 2D or 3D array of light signals; and    (c) a means for reading the array of light signals produced by the optical element.    
     
     
         23 . The optical analogue-to-digital converter of  claim 22  wherein the optical element is a hologram.  
     
     
         24 . The optical analogue-to-digital converter of  claim 22  wherein the optical element is an imposed hologram.  
     
     
         25 . The optical analogue-to-digital converter of  claim 22  wherein the optical element is an imposed hologram which has been recorded using a series of masks with apertures corresponding to the codes to be generated by the hologram.  
     
     
         26 . The optical analogue-to-digital converter of  claim 22  wherein the optical element is a computer generated hologram.  
     
     
         27 . The optical analogue-to-digital converter of  claim 22  wherein the optical element is a kinoform.  
     
     
         28 . The optical analogue-to-digital converter of  claim 22  wherein the optical element is a spatial light modulator.  
     
     
         29 . The optical analogue-to-digital converter of  claim 22  wherein the information contained in the light wave front is contained in the radius of curvature of the light wave front.  
     
     
         30 . The optical analogue-to-digital converter of  claim 22  wherein the information contained in the light wave front is contained in the direction vector of the light wave front.  
     
     
         31 . The optical analogue-to-digital converter of  claim 22  wherein the information contained in the light wave front is contained in both the radius of curvature and the direction vector of the light wave front.  
     
     
         32 . The optical analogue-to-digital converter of  claim 22  wherein the information contained in the light wave front is not contained in the intensity of the light wave.  
     
     
         33 . The optical analogue-to-digital converter of  claim 22  wherein the signals are in the form of light shapes.  
     
     
         34 . The optical analogue-to-digital converter of  claim 33  wherein the light shapes are spots.  
     
     
         35 . The optical analogue-to-digital converter of  claim 22  wherein the light source is a laser.  
     
     
         36 . The optical analogue-to-digital converter of  claim 35  wherein the laser emits light in the red or infrared spectra.  
     
     
         37 . The optical analogue-to-digital converter of  claim 35  wherein the laser is an He—Ne laser.  
     
     
         38 . The optical analogue-to-digital converter of  claim 22  wherein the means for reading the array of light signals is a visual observation means whereby a person can visually observe the digital signal.  
     
     
         39 . The optical analogue-to-digital converter of  claim 22  wherein the means for reading the array of light signals is a multi-element photodetector.  
     
     
         40 . The optical analogue-to-digital converter of  claim 22  wherein the means for reading the array of light signals is a 1D multi-element photodetector.  
     
     
         41 . The optical analogue-to-digital converter of  claim 22  wherein the means for reading the array of light signals is a 2D multi-element photodetector.  
     
     
         42 . The optical analogue-to-digital converter of  claim 39  further comprising a comparator operationally coupled via an electrical circuit to the multi-element photodetector wherein the comparator is configured to interpret a signal from the multi-element photodetector exceeding a predetermined threshold as a digital one and to interpret a signal not exceeding such predetermined threshold as a digital zero.  
     
     
         43 . The optical analogue-to-digital converter of  claim 39  further comprising a computer processor operationally coupled to the multi-element photodetector.  
     
     
         44 . The optical analogue-to-digital converter of  claim 42  further comprising a computer processor operationally coupled to the comparator.  
     
     
         45 . An apparatus for determining the distance from the apparatus to an object comprising an OADC of  claim 22 .  
     
     
         46 . A key and lock system comprising the converter of  claim 22 , and further comprising a circuit operationally connecting the comparator to the means for monitoring the light signals, and a lock mechanism operationally connected to the comparator and configured such that when an optical element, having the capacity to transform light from the light source into a predetermined digital code, is inserted in the optical path between the light source and the multi-element photodetector, the multi-element photodetector receives the predetermined digital code and sends a signal to the lock mechanism, thereby causing the lock mechanism to disengage.  
     
     
         47 . A method of making a hologram having the capacity to transform analogue information contained in a light wave front into digital information in the form of a 1D, 2D or 3D coded array of light shapes, and/or the capacity to transform digital information in the form of a 1D, 2D or 3D coded array of light shapes into analogue information contained in a light wave front, said method comprising: 
 (a) providing: 
 (i) a means for forming various parameters of light;  
 (ii) a means for forming a set of light codes, each code comprising one or a 1D, 2D or 3D series of light wave fronts;  
 (iii) a holographic recording material located in a receiving relationship to the light wave fronts;  
   (b) exposing the holographic material to a first light code; and    (c) repeating step (b) using another light code from the set of light codes until every light code in the set has been recorded on the holographic recording material.    
     
     
         48 . The method of  claim 47  further comprising the step of developing the recording material after every light code in the set has been recorded.  
     
     
         49 . The method of  claim 47  wherein the means for forming a set of light codes is a set of masks, wherein each mask has one or a series of apertures corresponding to a member of the set of light codes.  
     
     
         50 . The method of  claim 49  wherein the set of masks consists of a mask corresponding to every number in a binary code.  
     
     
         51 . The method of  claim 47  wherein the light code has 1-100 binary digits.  
     
     
         52 . The method of  claim 47  wherein the light code has 1-50 binary digits.  
     
     
         53 . The method of  claim 47  wherein the light code has 1-20 binary digits.  
     
     
         54 . The method of  claim 47  wherein the light code is a hexadecimal code.  
     
     
         55 . The method of  claim 47  wherein the light code is a 1D code.  
     
     
         56 . The method of  claim 47  wherein the light code is a 2D code.  
     
     
         57 . The method of  claim 47  wherein the light code is a 3D code.  
     
     
         58 . The method of  claim 47  wherein the information contained in the light wave front is contained in the radius of curvature of the light wave front.  
     
     
         59 . The method of  claim 47  wherein the information contained in the light wave front is contained in the direction vector of the light wave front.  
     
     
         60 . The method of  claim 47  wherein the information contained in the light wave front is contained in both the radius of curvature and the direction vector of the light wave front.  
     
     
         61 . The method of  claim 47  wherein the information contained in the light wave front is not contained in the intensity of the light wave.  
     
     
         62 . The method of  claim 47  wherein the means for forming a series of light spots comprises a laser.  
     
     
         63 . The method of  claim 62  wherein the laser emits light in the red or infrared spectra.  
     
     
         64 . The method of  claim 62  wherein the laser is a He—Ne laser.  
     
     
         65 . A hologram made by a process comprising: 
 (a) providing: 
 (i) a means for forming various parameters of light;  
 (ii) a means for forming a set of light codes, each code comprising one or a 1D, 2D or 3D series of light wave fronts;  
 (iii) a holographic recording material located in a receiving relationship to the light wave fronts;  
   (b) exposing the holographic material to a first light code; and    (c) repeating step (b) using another light code from the set of light codes until every light code in the set has been recorded on the holographic recording material.    
     
     
         66 . The hologram of  claim 65  further comprising the step of developing the recording material after every light code in the set has been recorded.  
     
     
         67 . The hologram of  claim 65  wherein the means for forming a set of light codes is a set of masks, wherein each mask has one or a series of apertures corresponding to a member of the set of light codes.  
     
     
         68 . The hologram of  claim 65  characterized in that the hologram has the capacity to transform analogue information contained in a light wave front into digital information.  
     
     
         69 . The hologram of  claim 68  wherein the information contained in the light wave front is contained in the radius of curvature of the light wave front.  
     
     
         70 . The hologram of  claim 68  wherein the information contained in the light wave front is contained in the direction vector of the light wave front.  
     
     
         71 . The hologram of  claim 68  wherein the information contained in the light wave front is contained in both the radius of curvature and the direction vector of the light wave front.  
     
     
         72 . The hologram of  claim 65  characterized in that the hologram has the capacity to transform analogue information contained in a series of light shapes into analogue information contained in a light wave front.  
     
     
         73 . The hologram of  claim 72  wherein the information contained in the light wave front is contained in the radius of curvature of the light wave front.  
     
     
         74 . The hologram of  claim 72  wherein the information contained in the light wave front is contained in the direction vector of the light wave front.  
     
     
         75 . The hologram of  claim 72  wherein the information contained in the light wave front is contained in both the radius of curvature and the direction vector of the light wave front.  
     
     
         76 . An apparatus for determining the distance from the apparatus to an object comprising an optical element having the capacity to transform information contained in a light wave front from the object into a 1D, 2D or 3D array of light signals.  
     
     
         77 . The apparatus of  claim 76 , further comprising a light source for impinging light upon the object.  
     
     
         78 . The apparatus of  claim 76  wherein the light source comprises a laser.  
     
     
         79 . The apparatus of  claim 78  wherein the laser emits light in the red or infrared spectra.  
     
     
         80 . The apparatus of  claim 78  wherein the laser is an He—Ne laser.  
     
     
         81 . The apparatus of  claim 76  further comprising a dim glass positioned in a receiving relationship to the light signals formed by the optical element.  
     
     
         82 . The apparatus of  claim 76  further comprising a means for monitoring the light signals.  
     
     
         83 . The apparatus of  claim 82  wherein the means for monitoring the light signals is a means which permits human observation of the light signals.  
     
     
         84 . The apparatus of  claim 82  wherein the means for monitoring the light signals is a multi-element photodetector.  
     
     
         85 . The apparatus of  claim 82  wherein the means for monitoring the light signals is a 1D multi-element photodetector.  
     
     
         86 . The apparatus of  claim 82  wherein the means for monitoring the light signals is a 2D multi-element photodetector.  
     
     
         87 . The apparatus of  claim 84  further comprising a comparator operationally coupled to the multi-element photodetector, wherein the comparator is configured to interpret a signal from the multi-element photodetector exceeding a predetermined threshold as a digital one and to interpret a signal not exceeding such predetermined threshold as a digital zero.  
     
     
         88 . The apparatus of  claim 87  further comprising a computer processor operationally coupled to the comparator.  
     
     
         89 . An apparatus for determining the distance from the apparatus to multiple three dimensionally arranged points on a surface comprising one or more optical elements having the capacity to transform information contained in a light wave front into a 2D or 3D array of light signals.  
     
     
         90 . The apparatus of  claim 89  further comprising a light source which can be directed at the surface, and wherein the optical element is in a receiving relationship to light reflected from the surface.  
     
     
         91 . The apparatus of  claim 89  wherein the light source is a laser.  
     
     
         92 . The apparatus of  claim 91  wherein the laser emits light in the red or infrared spectra.  
     
     
         93 . The apparatus of  claim 91  wherein the laser is an He—Ne laser.  
     
     
         94 . The apparatus of  claim 91  further comprising a dim glass positioned in a receiving relationship to the light signals from the optical element.  
     
     
         95 . The apparatus of  claim 91  further comprising a means for monitoring the light signals.  
     
     
         96 . The apparatus of  claim 95  wherein the means for monitoring the light signals is a means which permits human observation of the light signals.  
     
     
         97 . The apparatus of  claim 96  wherein the means which permits human observation of the light signals is a dim glass.  
     
     
         98 . The apparatus of  claim 95  wherein the means for monitoring the light signals is a multi-element photodetector.  
     
     
         99 . The apparatus of  claim 95  wherein the means for monitoring the light signals is a 1D multi-element photodetector.  
     
     
         100 . The apparatus of  claim 95  wherein the means for monitoring the light signals is a 2D multi-element photodetector.  
     
     
         101 . The apparatus of  claim 98  further comprising a comparator operationally coupled to the multi-element photodetector, wherein the comparator is configured to interpret a signal from the multi-element photodetector exceeding a predetermined threshold as a digital one and to interpret a signal not exceeding such predetermined threshold as a digital zero.  
     
     
         102 . The apparatus of  claim 98  further comprising a computer processor operationally coupled to the comparator.  
     
     
         103 . The apparatus of  claim 95  wherein the surface is on an article of manufacture.  
     
     
         104 . The apparatus of  claim 103  wherein the surface is on an article of manufacture on a production line.  
     
     
         105 . The apparatus of  claim 104  wherein the computer is programmed to control a reject mechanism on the production line, rejecting all articles which do not satisfy specified three-dimensional criteria.  
     
     
         106 . A manufacturing line quality control system comprising the apparatus of  claim 89  and further comprising: 
 (a) a circuit operationally connecting the comparator to the means for monitoring the light signals; and  
 (b) a computer processor operationally connected to the comparator, and operationally connected to a reject gate, wherein the computer processor is programmed to activate or deactivate a reject gate upon the receipt or non-receipt of a predetermined code.  
 
     
     
         107 . The apparatus of  claim 106  wherein the computer processor is programmed to adjust upstream processing parameters based receipt or non-receipt of a predetermined code.  
     
     
         108 . An optical digital-to-analogue converter comprising: 
 (a) a light source comprising an array of two or more light sources; and    (b) an optical element positioned in a receiving relationship to the array of two or more light sources and having the capacity to transform information contained in the array of two or more light sources into information contained in a light wave front.    
     
     
         109 . The optical digital-to-analogue converter of  claim 108  wherein the optical element is a hologram.  
     
     
         110 . The optical digital-to-analogue converter of  claim 108  wherein the optical element is an imposed hologram.  
     
     
         111 . The optical digital-to-analogue converter of  claim 108  wherein the optical element is a computer generated hologram.  
     
     
         112 . The optical digital-to-analogue converter of  claim 108  wherein the optical element is a kinoform.  
     
     
         113 . The optical digital-to-analogue converter of  claim 108  wherein the optical element is a spatial light modulator.  
     
     
         114 . The optical digital-to-analogue converter of  claim 108  wherein the information contained in the light wave front is contained in the radius of curvature of the light wave front.  
     
     
         115 . The optical digital-to-analogue converter of  claim 108  wherein the information contained in the light wave front is contained in the direction vector of the light wave front.  
     
     
         116 . The optical digital-to-analogue converter of  claim 108  wherein the information contained in the light wave front is contained in both the radius of curvature and the direction vector of the light wave front.  
     
     
         117 . The optical digital-to-analogue converter of  claim 108  wherein the information contained in the light wave front is not contained in the intensity of the light wave.  
     
     
         118 . The optical digital-to-analogue converter of  claim 108  wherein the signals are in the form of light shapes.  
     
     
         119 . The optical digital-to-analogue converter of  claim 118  wherein the light shapes are light spots.  
     
     
         120 . The optical digital-to-analogue converter of  claim 108  wherein the light source comprises a laser.  
     
     
         121 . The optical digital-to-analogue converter of  claim 120  wherein the laser emits light in the red or infrared spectra.  
     
     
         122 . The optical digital-to-analogue converter of  claim 120  wherein the laser is a He—Ne laser.  
     
     
         123 . A holographic display unit comprising an optical digital-to-analogue converter comprising: 
 (a) a light source comprising an array of two or more light sources; and    (b) an optical element positioned in a receiving relationship to array of two or more light sources and having the capacity to transform information contained in the array of two or more light sources into information contained in a light wave front.    
     
     
         124 . The holographic display unit of  claim 123  wherein the optical element is a hologram.  
     
     
         125 . The holographic display unit of  claim 123  wherein the optical element is an imposed hologram.  
     
     
         126 . The holographic display unit of  claim 123  wherein the optical element is a computer generated hologram.  
     
     
         127 . The holographic display unit of  claim 123  wherein the optical element is a kinoform.  
     
     
         128 . The holographic display unit of  claim 123  wherein the optical element is a spatial light modulator.  
     
     
         129 . The holographic display unit of  claim 123  wherein the information contained in the light wave front is contained in the radius of curvature of the light wave front.  
     
     
         130 . The holographic display unit of  claim 123  wherein the information contained in the light wave front is contained in the direction vector of the light wave front.  
     
     
         131 . The holographic display unit of  claim 123  wherein the information contained in the light wave front is contained in both the radius of curvature and the direction vector of the light wave front.  
     
     
         132 . The holographic display unit of  claim 123  wherein the information contained in the light wave front is not contained in the intensity of the light wave.  
     
     
         133 . The holographic display unit of  claim 123  wherein the array of two or more light sources produces light shapes.  
     
     
         134 . The holographic display unit of  claim 133  wherein the light shapes are spots.  
     
     
         135 . The holographic display unit of  claim 123  wherein the array of two or more light sources comprises a laser.  
     
     
         136 . The holographic display unit  135  wherein the laser emits light in the visible spectrum.  
     
     
         137 . The holographic display unit  135  wherein the array of two or more light sources comprises a laser which emits light in the red spectrum, a laser which emits light in the green spectrum and a laser which emits light in the blue spectrum.  
     
     
         138 . An optical digital decoder comprising: 
 (a) a light source comprising an array of two or more light sources;    (b) an optical element positioned in a receiving relationship to array of two or more light sources and having the capacity to transform information contained in the array of two or more light sources into an array of two or more light spots; and    (c) a means for reading the array of light signals produced by the optical element.    
     
     
         139 . The optical digital decoder of  claim 138  wherein the optical element is a hologram.  
     
     
         140 . The optical digital decoder of  claim 138  wherein the optical element is an imposed hologram.  
     
     
         141 . The optical digital decoder of  claim 138  wherein the optical element is a computer generated hologram.  
     
     
         142 . The optical digital decoder of  claim 138  wherein the optical element is a kinoform.  
     
     
         143 . The optical digital decoder of  claim 138  wherein the optical element is a spatial light modulator.  
     
     
         144 . The optical digital decoder of  claim 138  wherein the information contained in the light wave front is contained in the radius of curvature of the light wave front.  
     
     
         145 . The optical digital decoder of  claim 138  wherein the information contained in the light wave front is contained in the direction vector of the light wave front.  
     
     
         146 . The optical digital decoder of  claim 138  wherein the information contained in the light wave front is contained in both the radius of curvature and the direction vector of the light wave front.  
     
     
         147 . The optical digital decoder of  claim 138  wherein the information contained in the light wave front is not contained in the intensity of the light wave.  
     
     
         148 . The optical digital decoder of  claim 138  wherein the array of two or more light sources comprises a laser.  
     
     
         149 . The optical digital decoder of  claim 148  wherein the laser emits light in the red or infrared spectra.  
     
     
         150 . The optical digital decoder of  claim 148  wherein the laser is an He—Ne laser.  
     
     
         151 . The optical digital decoder of  claim 138  wherein the means for reading the digital signal is a visual observation means whereby a person can visually observe the digital signal.  
     
     
         152 . The optical digital decoder of  claim 138  wherein the means for reading the digital signal is a multi-element photodetector.  
     
     
         153 . The optical digital decoder of  claim 138  wherein the means for reading the digital signal is a 1D multi-element photodetector.  
     
     
         154 . The optical digital decoder of  claim 138  wherein the means for reading the digital signal is a 2D multi-element photodetector.  
     
     
         155 . The optical digital decoder of  claim 138  further comprising a comparator operationally coupled to the multi-element photodetector, wherein the comparator is configured to interpret a signal from the multi-element photodetector exceeding a predetermined threshold as a digital one and to interpret a signal not exceeding such predetermined threshold as a digital zero.  
     
     
         156 . The optical digital decoder of  claim 155  further comprising a computer processor operationally coupled to the comparator.