Optically activated keyboard for digital system

Abstract

An optically activated keyboard provides inputs to a digital computer or the like. The keyboard includes a key housing having formed therein a wave guide matrix of intersecting columns and rows with light emitting diodes (LED's) installed in one end of each column and photo transistors installed in one end of each row. A plurality of keys are mounted at the top surface of the housing, each key having a plunger which projects through a corresponding aperture in the housing, when the key is depressed. The intersections of the columns and rows are located directly beneath the apertures so that when a key is depressed, its plunger intrudes into the volume at the intersection. Each plunger, in concert with the wave guide intersection, forms a light polarizing system. In the preferred embodiment, each plunger has a reflecting face that is angled to reflect light from the LED in the corresponding column into the corresponding row, finally impinging against the appropriate photo transistor. In this preferred embodiment, when the button is fully depressed, the plunger provides space between the bottom of the plunger and the bottom of the wave guide so that light traveling in the column or row is permitted to pass and thereby to detect any other keys that have been depressed in the particular column or row.

I claim: 
     
       1. Manual input apparatus having scanning means, for providing inputs to data handling apparatus, comprising: (a) key housing means having a matrix of apertures formed through the top surface thereof;   (b) wave guide means formed in the key housing means in a matrix configuration of columns and rows with the intersections of the columns and rows aligned below the apertures;   (c) light source means connected to each column, each light source means being turned on and off in a predetermined order by the scanning means;   (d) light detecting means connected to each row, activated by impinging light to provide a signal indicative of detection;   (e) key means resiliently mounted over each aperture and having a plunger for passing through the aperture when a key means is selected and depressed; and   (f) polarizing means formed by each plunger to reflect light, from a light source means that is turned on at a scanned column when the key means has been depressed, through the row at that intersection to the light detecting means associated with that row wherein each plunger is dimensioned so that when the associated key means is depressed, the plunger intrudes into the wave guide means a predetermined distance, defining a volume between the bottom of each plunger and the bottom of the wave guide means to permit light to pass through the volume in the scanned column to allow detection of other depressed keys in the scanned column and associated rows.   
     
     
       2. The apparatus of claim 1 further comprising optical fiber means for connecting each light source means to each column and for connecting each light detecting means to each row. 
     
     
       3. The apparatus of claim 1 wherein each plunger has a reflecting surface formed at a desired angle to the rows and columns to reflect light into the row at the intersection of a depressed key means. 
     
     
       4. The apparatus of claim 2 wherein each plunger has a reflecting surface formed at a desired angle to the rows and columns to reflect light into the row at the intersection of a depressed key means. 
     
     
       5. The apparatus of claim 3 wherein the light source means comprises a light emitting diode for each column and the light detecting means comprises a photo transistor for each row. 
     
     
       6. The apparatus of claim 4 wherein the light source means comprises a light emitting diode for each column and the light detecting means comprises a photo transistor for each row. 
     
     
       7. Digital apparatus comprising: (a) data handling means; and   (b) manual input means operatively connected to supply input signals to the data handling means, the manual input means comprising:   key housing means having a matrix of apertures formed through the top surface thereof,   wave guide means formed in the key housing means in a matrix configuration of columns and rows with the intersections of the columns and rows aligned below the apertures,   light source means connected to each column, each light source means being turned on and off in a predetermined order by the scanning means,   light detecting means connected to each row, activated by impinging light to provide a signal indicative of detection;   key means resiliently mounted over each aperture and each key means having a plunger for passing through the aperture when a key means is selected and depressed, and   polarizing means formed by each plunger to reflect light, from a light source means that is turned on at a scanned column when the key means has been depressed, through the row at that intersection to the light detecting means associated with that row wherein each plunger is dimensioned so that when the associated key means is depressed, the plunger intrudes into the wave guide means a predetermined distance, defining a volume between the bottom of each plunger and the bottom of the wave guide means to permit light to pass through the volume in the scanned column to allow detection of other depressed keys in the scanned column and associated rows.   
     
     
       8. The apparatus of claim 7 further comprising optical fiber means for connecting each light source means to each column and for connecting each light detecting means to each row. 
     
     
       9. The apparatus of claim 7 wherein each plunger has a reflecting surface formed at a desired angle to the rows and columns to reflect light into the row at the intersection of a depressed key means. 
     
     
       10. The apparatus of claim 8 wherein each plunger has a reflecting surface formed at a desired angle to the rows and columns to reflect light into the row at the intersection of a depressed key means. 
     
     
       11. The apparatus of claim 9 wherein the light source means comprises a light emitting diode for each column and the light detecting means comprises a photo transistor for each row. 
     
     
       12. The apparatus of claim 10 wherein the light source means comprises a light emitting diode for each column and a light detecting means comprises a photo transistor for each row. 
     
     
       13. The apparatus of claim 7 wherein the data handling means comprises a digital computer. .Iadd. 
     
     
       14.  Manual input apparatus for providing inputs to data handling apparatus, comprising: (a) key housing means having a matrix of apertures therein extending to the top surface thereof;   (b) plural light transmitting channels of predetermined cross-sectional dimension disposed in the key housing means in a matrix configuration of columns and rows with each intersection of a column and row aligned with an associated one of said apertures;   (c) light source means for providing a light beam along each of said columns;   (d) light detecting means disposed in each said row and responsive to the impingement of said light thereon to provide a signal indicative of said impingement; and   (e) plural key members, each said key member mounted for reciprocal movement within one said aperture and having a reflective surface of smaller cross sectional area than the cross sectional area of said light beam in a direction normal to the axis of travel of said light beam along said column, said key member responsive to predetermined said key member movement within said aperture to reflect into the associated row the portion of any light beam travelling along the associated column and impinging upon said reflective surface, said key member permitting the remainder of said light beam to continue travel along said column. .Iaddend. .Iadd.   
     
     
       15.  The apparatus of claim 14 wherein said reflective surface extends across only a portion of said column and a portion of the path of travel of said light beam along said column. .Iaddend. .Iadd.16. The apparatus of claim 14 wherein said light source means further includes a separate light source associated with each said column and scanning means to sequentially turn on and off each said light source in a predetermined order. .Iaddend. .Iadd.17. The apparatus of claim 15 wherein said light source means further includes scanning means and a light source for each said column, said scanning means turning said light source in each said column on and off sequentially in said predetermined order. .Iaddend. .Iadd.18. The apparatus of claim 14 further including optical fiber means for connecting each light source means to each column and for connecting each light detecting means to each row. .Iaddend. .Iadd.19. The apparatus of claim 14 wherein each said reflective surface is disposed at a predetermined angle to reflect light from the row associated therewith into the column associated therewith. .Iaddend. .Iadd.20. The apparatus of claim 16 wherein each said light source is a light emitting diode and each said light detecting means comprises a phototransistor. .Iaddend. .Iadd.21. The apparatus of claim 17 wherein each said light source is a light emitting diode and each said light detecting means comprises a phototransistor. 
     
     
        .Iaddend. .Iadd.22.  Manual input apparatus for providing inputs to data handling apparatus, comprising: (a) key housing means having a matrix of apertures therein extending to the top surface thereof;   (b) plural light transmitting channels disposed in a matrix configuration of columns and rows with each intersection of a column and row aligned with an associated one of said apertures;   (c) light source means for providing a light beam along each of said columns including plural light sources each said light source providing a light beam along an associated one of said columns and scanning means for turning said light sources on and off sequentially in a predetermined order;   (d) light detecting means disposed in each said row responsive to the impingement of said light thereon to provide a signal indicative of said impingement;   (e) plural key members, each said key member mounted for reciprocal movement within one said aperture; and   (f) polarizing means disposed at the end of each said key member in the associated aperture and responsive to predetermined said key member movement within said aperture to reflect into the associated row light travelling along the associated column and impinging upon said reflective surface. .Iaddend. .Iadd.23. The apparatus of claim 22 further including optical fiber means for connecting each light source means to each column and for connecting each light detecting means to each row. .Iaddend.   
     
     
        .Iadd.4.  The apparatus of claim 22 wherein each said reflective surface is disposed at a predetermined angle to reflect light from the row associated therewith into the column associated therewith. .Iaddend. .Iadd.25. The apparatus of claim 22 wherein each said light source is a light emitting diode and each said light detecting means comprises a phototransistor. .Iaddend. .Iadd.26. The apparatus of claim 24 wherein each said light source is a light emitting diode and each said light 
     
     
        detecting means comprises a phototransistor. .Iaddend. .Iadd.27.  Digital apparatus, comprising: (a) data handling means; and   (b) manual input means operatively connected to supply input signals to the data handling means, the manual input means comprising:   (c) key housing means having a matrix of apertures therein extending to the top surface thereof;   (d) plural light transmitting channels of predetermined cross-sectional dimension disposed in the key housing means in a matrix configuration of columns and rows with each intersection of a column and row aligned with an associated one of said apertures;   (e) light source means for providing a light beam along each of said columns;   (f) light detecting means disposed in each said row and responsive to the impingement of said light thereon to provide a signal indicative of said impingement; and   (g) plural key members, each said key member mounted for reciprocal movement within one said aperture and having a reflective surface of smaller cross sectional area than the cross sectional area of said light beam in a directional normal to the axis of travel of said light beam along said column, said key member responsive to predetermined said key member movement within said aperture to reflect into the associated row the portion of any light beam travelling along the associated column and impinging upon said reflective surface, said key member permitting the remainder of said light beam to continue travel along said column. .Iaddend. .Iadd.28. The apparatus of claim 27 wherein said reflective surface extends across only a portion of said column and a portion of the path of travel of said light beam along said column. .Iaddend. .Iadd.29. The apparatus of claim 27 wherein said light source means further includes a separate light source associated with each said column and scanning means to sequentially turn on and off each said light source in a predetermined order. .Iaddend. .Iadd.30. The apparatus of claim 28 wherein said light source means further includes scanning means and a light source for each said column, said scanning means turning said light source in each said column on and off sequentially in said predetermined order. .Iaddend. .Iadd.31. The apparatus of claim 27 further including optical fiber means for connecting each light source means to each column and for connecting each light detecting means to each row. .Iaddend. .Iadd.32. The apparatus of claim 27 wherein each said reflective surface is disposed at a predetermined angle to reflect light from the row associated therewith into the column associated therewith. .Iaddend. .Iadd.33. The apparatus of claim 29 wherein each said light source is a light emitting diode and each said light detecting means comprises a phototransistor. .Iaddend.   
     
     
        .Iadd.     The apparatus of claim 30 wherein each said light source is a light emitting diode and each said light detecting means comprises a phototransistor. .Iaddend. .Iadd.35. Digital apparatus, comprising: (a) data handling means; and   (b) manual input means operatively connected to supply input signals to the data handling means, the manual input means comprising:   (c) key housing means having a matrix of apertures therein extending to the top surface thereof;   (d) plural light transmitting channels disposed in a matrix configuration of columns and rows with each intersection of a column and row aligned with an associated one of said apertures;   (e) light source means for providing a light beam along each of said columns including plural light sources each said light source providing a light beam along an associated one of said columns and scanning means for turning said light sources on and off sequentially in a predetermined order;   (f) light detecting means disposed in each said row responsive to the impingement of said light thereon to provide a signal indicative of said impingement;   (g) plural key members, each said key member mounted for reciprocal movement within one said aperture; and   (f) polarizing means disposed at the end of each said key member in the associated aperture and responsive to predetermined said key member movement within said aperture to reflect into the associated row light travelling along the associated column and impinging upon said reflective surface. .Iaddend. .Iadd.36. The apparatus of claim 35 further including optical fiber means for connecting each light source means to each column and for connecting each light detecting means to each row. .Iaddend. .Iadd.37. The apparatus of claim 35 wherein each said reflective surface is disposed at a predetermined angle to reflect light from the row associated therewith into the column associated therewith. .Iaddend. .Iadd.38. The apparatus of claim 35 wherein each said light source is a light emitting diode and each said light detecting means comprising a phototransistor. .Iaddend. .Iadd.39. The apparatus of claim 37 wherein each said light source is a light emitting diode and each said light   
     
     
        detecting means comprises a phototransistor. .Iaddend. .Iadd.40.  Manual input apparatus for providing inputs to data handling apparatus, comprising: (a) key housing means having a matrix of apertures therein extending to the top surface thereof;   (b) plural light transmitting channels disposed in a matrix configuration of columns and rows with each intersection of a column and row aligned with an associated one of said apertures, each said light transmitting channel defined by walls having a reflectivity of about that of a polycarbonate with a refractive index of 1.5 to a wavelength of 0.651 microns;   (c) light source means for providing a light beam along each of said columns including plural light sources each said light source providing a light beam along an associated one of said columns and scanning means for turning said light sources on and off sequentially in a predetermined order;   (d) light detecting means disposed in each said row responsive to the impingement of said light thereon to provide a signal indicative of said impingement; and   (e) plural key members, each said key member mounted for reciprocal movement within one said aperture and having means disposed at the end of each said key member in the associated aperture and responsive to predetermined said key member movement within said aperture to reflect into the associated row a portion of light travelling along the associated column and impinging upon said reflective surface and permitting the remainder of said light to continue travel along said column. .Iaddend.   
     
     
        .Iadd.41.  The apparatus of claim 40 further including optical fiber means for connecting each light source means to each column and for connecting each light detecting means to each row. .Iaddend. .Iadd.42. The apparatus of claim 40 wherein each said reflective surface is disposed at a predetermined angle to reflect light from the row associated therewith into the column associated therewith. .Iaddend. .Iadd.43. The apparatus of claim 40 wherein each said light source is a light emitting diode and each said light detecting means comprises a phototransistor. .Iaddend. .Iadd.44. The apparatus of claim 42 wherein each said light source is a light emitting diode and each said light detecting means comprises a 
     
     
        phototransistor. .Iaddend. .Iadd.45.  Digital apparatus, comprising: (a) data handling means; and   (b) manual input means operatively connected to supply input signals to the data handling means, the manual input means comprising:   (c) key housing means having a matrix of apertures therein extending to the top surface thereof;   (d) plural light transmitting channels disposed in a matrix configuration of columns and rows with each intersection of a column and row aligned with an associated one of said apertures, each said light transmitting channel defined by walls having a reflectivity of about that of a polycarbonate with a refractive index of 1.5 at a wavelength of 0.651 microns;   (e) light source means for providing a light beam along each of said columns including plural light sources each said light source providing a light beam along an associated one of said columns and scanning means or turning said light sources on and off sequentially in a predetermined order;   (f) light detecting means disposed in each said row responsive to the impingement of said light thereon to provide a signal indicative of said impingement;   (g) plural key members, each said key member mounted for reciprocal movement within one said aperture and having means disposed at the end of each said key member in the associated aperture and responsive to predetermined said key member movement within said aperture to reflect into the associated row a portion of light travelling along the associated column and impinging upon said reflective surface and permitting the remainder of said light to continue travel along said column. .Iaddend. .Iadd.46. The apparatus of claim 45 further including optical fiber means for connecting each light source means to each column and for connecting each light detecting means to each row. .Iaddend. .Iadd.47. The apparatus of claim 45 wherein each said reflective surface is disposed at a predetermined angle to reflect light from the row associated therewith into the column associated therewith. .Iaddend. .Iadd.48. The apparatus of claim 45 wherein each said light source is a light emitting diode and each said light detecting means comprises a phototransistor. .Iaddend. .Iadd.49. The apparatus of claim 47 wherein each said light source is a light emitting diode and each said light detecting means comprises a phototransistor. .Iaddend.