Two-way Projection System For Data Input

Abstract

A data input terminal comprising a two-way projection system for the selection of desired input messages from a library of selectable messages. The library of messages is optically displayed in groups on a projection screen and selection of desired messages from the projected group is optically detected to provide electrical output signals representing screen locations corresponding to the selected messages.

Description

FIELD OF THE INVENTION

This invention relates to data input terminals and in particular to terminals for the optical selection of input data from a library of information.

BACKGROUND OF THE INVENTION

With digital information handling systems becoming more commonly used in all fields, increasing demand is being expressed for the provision of efficient data input terminals which permit the selection of input data from a large library of available inputs. In such applications it is necessary to both display for the operator's selection the information from which he is permitted to select predetermined input messages and also to permit simple and foolproof communication to the input terminal of the operator's data selection.

In the rapidly expanding field of medical data systems, instances exist for which it is desirable to provide multiple data input terminals having at low cost, flexibilities and capacities not previously available in the prior art systems. In one such application, information handling systems are provided in hospitals to process the flow of medical and administrative information. In such cases it is necessary to provide a plurality of information input terminals whereby, for example, individual nursing stations can call up orders or services for individual patients and select them from a vast body of possible medical requests.

Exemplary prior systems which employ a switch matrix and overlay system have been found satisfactory for many applications but are limited in the size of the input data library and often use mechanical switches to enable selection of input data. Prior systems which use a projection of selectable input data without switches for data selection require complex and expensive scanning systems to enable electro-optical separation of different portions of the projected image for identifying the image area corresponding to selected data. One prior art attempt to provide this capability is shown in Harris, U.S. Pat. No. 3,534,359.

BRIEF SUMMARY OF THE INVENTION

The feature of rapid selection of input data from a vast library of available input data is provided according to the present invention in an input terminal for use with a medical information handling system. The information input terminal employs a fully optical data display and selection system which permits rapid access to and selection from the whole input data library. The fully optical design is economical in the use of display area to increase the possible library size and provides for input data selection without the use of costly mechanical switches.

In the preferred embodiment the input data library is stored in high density on a plurality of photographic transparencies. The transparency containing a desired repertory of input data is selected from the plurality of stored transparencies and projected by a rear projection system onto a translucent screen for operator viewing. The screen image is projected backward from the illuminated surface of the screen through an optical system onto a photodetector array with predetermined alignment between screen image locations and detectors in the array but at an optical intensity insufficient to activate any detector in the array. When the operator wishes to make a data input selection a light source is applied to the screen at a location corresponding to the selected data to cause an intense spot of light to be focused onto the detector array activating a corresponding detector. The detector array is scanned to determine the activated detector and a digital signal is generated to represent the activated detector. The array scanning and activated detector determination are made with provisions to reject spurious activations. An additional digital signal is generated to indicate which transparency is displayed and together, the two digital signals completely specify selected input information from a very large number of possible choices. The use of projectable transparencies for each repertory further facilitates modifications to the library of selectable inputs by simple replacement of one or more transparencies.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features of the present invention will be more fully understood by reference to the detailed description of preferred embodiments presented below for purposes of illustration, and not by way of limitation, and to the accompanying drawings of which:

FIG. 1 is a pictorial and schematic diagram of a two-way projection system according to the invention;

FIG. 1A is a view of a typical information repertory projected by the system of FIG. 1;

FIG. 2 is a diagrammatic view of the projection portion of the system of FIG. 1;

FIG. 3 is a diagram of a modified projection screen for use in the invention with a reflective pointer for data selection;

FIG. 4 presents a modification of the projection system and reflective pointer for use in the invention; and

FIG. 5 is a pictorial and schematic diagram of a modified detector and imaging system for use in the invention.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT

To provide a flexible, easy to use, and low cost input terminal for selection of multiple choice input data a two-way projection system is shown in FIG. 1. The components indicated could typically be contained within a small console but are shown without reference to the console in FIG. 1 for clarity of understanding. In a rear projection system, a projection screen 12 is positioned to receive light directed from a projector 14 at a focal plane of the projected light. Light eminating from the rear projection surface of the screen 12 is focused by a lens system 16 onto the plane of an array of photodetectors 18.

The projector 14 may typically be any of the several available, externally programmable random access projectors such as, for example, the Kodak Carousel RA-950 or RA-960 projector. The projector 14 has a magazine or tray 20 from which 80, or 140 slides may be selected for projection in response to externally applied control signals to be described below.

A typical slide repertory is indicated in FIG. 1A wherein an image 22 is shown to contain a plurality of selectable input messages 24 associated with selection points 26. The repertory of slide 22 might find typical application in a hospital input terminal where it may be desired to provide to the hospital data system selected pharmacy or test orders pertinent to a particular patient. This selection is made directly from a projected list of possible pharmacy or service instructions presented in the format 22. It is to be noted that more or less messages may be provided in the same repertory.

A selector switch system 28 is provided adjacent to the projection screen 12 for example when mounted in a console to enable the terminal operator to manually select which of the 80 or 140 slides is desired for display and accordingly for selection of particular information contained thereon. The output of the switch operates through the projector 14 to cause the magazine 20 to be appropriately positioned for displaying that slide.

Selection of desired information from a displayed image 22 is achieved by illuminating a point 26 with the light spot from a small light source such as pen light 30. The projection screen 12 will normally be of a translucent material which is sufficiently light dispersive to provide a clear image of slides projected by projector 14 onto screen 12 and also sufficiently transmissive of light to transmit significant portions of illumination provided by the pen light 30 from the operator's side of screen 12 to the reverse side facing the projector 14 and lens system 16. The pen light 30 and screen 12 are adapted to provide radiation of light from the back of screen 12 toward the lens system 16 in a quantity substantially greater than diffused illumination from the projector 14 or from ambient room light. This may be facilitated by not subjecting the points 26 to illumination from the projector and by employing a size for point 26 which corresponds to the detector size.

Typically the array 18 will contain a matrix of photosensitive transistors 32. The lens system 16 and array 18 are placed adjacent to the projector 14 but slightly off axis from each other due to physical placement requirements. The photosensitive detector array 18 is positioned with the lens system 16 so that light from each selection point 26 is imaged onto a corresponding photosensitive transistor 32. The number of selection spots 26 which can be placed on a single slide will be generally limited by the abilities of the individual projector 14 to consistently position the projected image.

As indicated in FIG. 1, the collectors of all transistors 32 in a single row are tied together and biased through a single resistor 34. All resistors 34 are supplied from a single voltage source 36. Electrical connections are fed from each row at the point of junction with the collectors of transistors 32 to row output terminals of the array 18 which are in turn connected to a sampling, multiplexer circuit 38. Multiplexer circuit 38 provides at its output, each of the output signals specified by digital signals from a counter 40.

The emitters of all phototransistors 32 in a column are joined together and electrically connected externally of array 18 to a decoder circuit 42 which sequentially grounds the emitters a column at a time in response to a control input from counter 40. The counter 40 continuously cycles through a predetermined count in response to clocking signals from an oscillator 44. Typically most significant bits from the counter 40 correspond to column addresses and are applied as the control signal to the decoder circuit 42 which, for each binary state in the most significant bits, grounds a corresponding column of emitters from the array 18. The least significant bits from the counter 40 are applied to the sampling circuit 38 to connect to a DATA output line 46 a corresponding one of its row inputs depending upon the binary state of the least significant bits.

The total binary count of the counter 40 is applied to an address storage register 48. The register 48 is caused to respond to and store the digital contents of the counter 40 by a LOAD input from an AND circuit 50. The AND circuit 50 receives the output of the multiplexer circuit 38 as well as a NOT HOLD input signal on a line 52. The NOT HOLD signal will be subsequently described, but generally indicates a system preparedness to accept new information. When both signals occur, the counter 40 is at a binary count which connects signals at the decoder 42 and sampler 38 to the row and column of an illuminated photosensitive transistor. The register 48 is loaded with the digital contents of the counter 40 at that time, this digital signal indicating which photodetector is illuminated. A comparator 54 responds to the stored data in register 48 and the output of the counter 40 to provide an address output on a line 56 (ADR) in response to digital equality between its two inputs. As is apparent, circuit 54, according to conventional digital clocking techniques, will make its comparison of the previously stored counter signal with the about to be stored counter signal.

To provide a verification of the illumination of a photosensitive transistor 32 a verification counter 58 is provided to cause several sequential rapid samplings of the same photosensitive transistor 32 before acceptance of that indication as a valid input of data. To accomplish this an AND gate 60 receives the ADR signal from the line 56 and the DATA output on line 46 of multiplexer circuit 38 as well as the NOT HOLD signal on line 52 and a NOT CHAR signal to be explained. Coincidence of all four signals causes application of a signal to the count-up input of counter 58 causing it to advance one digital count. A further AND gate 62 receives the ADR address output the HOLD signal, a NOT DATA signal derived from line 52 and the NOT CHAR signal. Coincidence of all signals causes the counter 58 to count down a digital step in response to a signal applied to its count-down input from the gate 62. The counter 58 is preset through an OR gate 64 when either a signal is received from an AND gate 66 of an AND gate 68. The AND gate 66 receives a NOT ADR signal derived from the address signal on line 56 and the DATA signal on line 46, the NOT HOLD signal and the NOT CHAR signal. The AND gate 68 receives the same last two mentioned signals and ADR address signal on line 56 and the NOT DATA signal derived from line 46.

The indicated NOT signals may be derived from any of the known techniques including inverting outputs or inputs, or separate inverters.

It can be seen that the counter 58 is preset through the OR gate 64 if the DATA signal from the multiplexer circuit 38 is received at a time when the stored address in the register 48 is different from the state of the counter 40 as indicated by the NOT ADR signal and if the NOT HOLD and NOT CHAR conditions exist. Similarly, if an ADR signal is preset with NOT DATA and the NOT HOLD and NOT CHAR signals exist, the counter 58 will be preset.

The counter 70 is caused to count up when both the ADR and the DATA signals are present provided that NOT HOLD and NOT CHAR exist. After a sufficient digital count, the counter 58 provides a count-up complete signal to a hold register 70 and a new character register 72. This count-up complete signal will cause the hold register 70, typically a bistable memory circuit, to provide the HOLD signal on an output 52. This signal is applied as indicated above in the system. At the same time the new character register 72 responds to the count-up complete signal 74 to produce a new character output signal CHAR on line 74 to indicate that the digital number in the register 48 represents the message selected for input through the terminal. This digital representation is available at output line 76 of register 48.

The CHAR signal and data on line 76 are applied to a utilization device 78 which may be a data processing system for a hospital. After receiving the data on line 76, the utilization device 78, returns a clear signal to reset the new character register 72. For purposes of understanding this invention the utilization device 72 may be viewed as providing a delayed clear output in response to the CHAR signal to reset the register 72.

When the HOLD signal is present and after the register 72 is cleared to provide the NOT CHAR signal, the AND gate 62 will respond to the ADR address signal and the NOT DATA signal to cause counter 58 to count down a predetermined number of digital steps until a count-down complete signal is generated and applied as a reset to the hold circuit 70 to remove the HOLD signal and establish the NOT HOLD signal. This count-down function provides a predetermined delay after the acceptance of information and after the removal of the light spot as produced by the pen light 30 from the surface of the screen 12 to prevent acceptance of the same information twice unless it is purposely desired.

Along with the CHAR signal on line 74, a SLIDE KEY signal on line 80 from the switches 28 indicating the particular slide displayed on the screen 12 is applied to the utilization device 80. The slide and selection inputs on lines 76 and 80 to the utilization device 78 provide complete information on the specific message selected by the operator from the vast library available from all slides in the magazine 20.

Referring now to FIG. 2 a diagrammatic view of the two-way projection system is indicated showing the adjacent relationship of the projection optics with the detector and imaging optics. In particular a lamp 82 is provided to direct light through a condenser system 84 and a slide transparency 86 to a lens system 88. Light from the lens system 88 is imaged on a translucent projection surface or screen 90. The projection surface 90 may be a glass or plastic plate constructed as indicated above to provide the necessary degree of translucence for presenting an image of the slide as well as transmitting light from the pen light 30. Preferably, the screen 90 is marked to indicate the locations of the selection points 26. This may be achieved with an opaque surface coating 92 which is perforated with transparent portions 94 in areas corresponding to the selection points 26 and has translucent regions 96 in the area of projection for message selections 24.

The light from the pen light 30 is imaged through transparent portions 94 by an optics system 98 onto a photosensitive detector array 100 which is in turn sampled by electronics 102 as indicated in FIG. 1.

In FIG. 3 a modification of the screen and pen light is indicated in sectional and pictorial views. A screen 104 has on the rear side facing the projector a Fresnel lens 106 and on the opposite side a dispersive coating 108 which is open at portions 110 corresponding to the selection points 26 to provide greater transparency. In place of pen light 30 a mirror 112 may be placed on the coating 108 at the transparent portions 110 to reflect back illumination from the projector with a high specular characteristic and by employing the qualities of the Fresnel lens to direct it toward the optical system 98 and the detector array 100 as shown in FIG. 2. By placing the mirror 112 on the plane coated surface 108 of the screen 90 proper axial alignment of the mirror 112 is insured. As is apparent for the FIG. 3 embodiment, the slides will be designed to provide illumination through points 26 to portions 110.

In FIG. 4 a further modification is indicated wherein a screen 114 is provided with a dispersive coating 116 similar to coating 108 and transparent portions 118 aligned with the points 26. A corner reflector 120 is provided for placement over the transparent portions 118 to reflect light from the projector backwards along its path of incidence. The complete optical system is shown in FIG. 4 to include a beam splitter mirror 122 in the path of illumination from projector 14 to screen 114. Mirror 122 passes light from the projector 14 but reflects light returned by retroreflector 120 through a lens system 124 to a detector array 126 for electronic sampling as indicated above. The screen 104 and mirror 112 of FIG. 3 may also be used in the FIG. 4 embodiment to replace screen 114 and retroreflector 120.

In FIG. 5 a further modification is indicated to provide operation with fewer number photosensitive detectors than in array 18, 100 or 126 and without a focusing lens 16, 98 or 124. This makes higher sensitivity more practical in the detectors. The imaging system comprises a mask 128 having crossed slits 130 and 132 in respective vertical and horizontal orientations. These slits cooperate with an array 138 of detectors arranged in a single vertical column 134 and a single horizontal row 136. No detector is in both column 134 and row 136. Vertical slit 130 will cause a vertical bar of light to fall on array 138 for each selection, and that bar will illuminate a detector in row 136 corresponding to the column on the displayed repertory containing the selected message. Similarly, horizontal slit 132 causes a horizontal bar of light which illuminates a detector in column 134 corresponding to the displayed row containing the selected message.

A counter 140 has its most significant bits applied through a multiplexer 142 to sample the state of each of the photodetectors in the horizontal row 136. A multiplexer 144 is provided to sample the photodetectors in the column 134 in response to the least significant bits in counter 140. The multiplexers 142 and 144 detect illumination of a detector in the row 136 and column 134 and apply respective signals indicative thereof to an AND gate 146. Gate 146 also receives the NOT HOLD signal as provided by the FIG. 1 circuitry. The gate 146 operates similarly to gate 50 in FIG. 1 and provides a load signal to a storage register 148 when its three input conditions are met. Register 148 is similar to register 48 of FIG. 1 and stores the digital state of counter 140. The remaining circuitry may follow the pattern of FIG. 1.

In place of slits 130 and 132 in mask 128, discrete holes may be employed. Additionally, slits which do not cross may be employed and may be made wide to accept cylindrical lenses to increase the intensity of the bars of light.

With the above indicated projection and electronic detection system it is possible to provide a library of selectable information for multiple choice question and answer purposes or selection of input data from a vast library of possible inputs by providing a raster of selectable data on each of a plurality of transparent images. A particular image and the corresponding selection from that image are encoded to provide an output indication of the desired information and to provide verification for each selection. The terminal furthermore provides rapid entry of a vast amount of data with selections from a plurality of different slides by using a random access projector. Moreover, the problems of switch contact bounce are eliminated by using an optical system and multiple scan verification for responding to the selection of individual data from each display raster.

The library of selectable input information is easily altered by providing new transparencies and by changing the recognized information in the utilization device as for example by altering addressable look-up tables. The selection sequence may be made adaptive as by employing data processing to define the repertory to display on the basis of past selections.

It will occur to those skilled in the art that in addition to the system disclosed above, further modifications and alternatives can be devised to implement the spirit of the invention and accordingly it is intended to limit the scope of the invention only as indicated in the following claims.

Claims

What is claimed is:

1. A two-way projection system for presentation of and selection from repertories of selectable information said system comprising:

a projection surface;

means for projecting a repertory of selectable information on said projection surface in predetermined alignment;

a light reflector for placement at selected positions on said projection surface to reflect light provided by said projecting means from the selected positions on said projection surface associated with selectable information; and

means responsive to light from said light reflector emanating by reflection from said projection surface for detecting the relative position of said selected position on said projection surface thereby to provide an indication of the location on said projected image of said selected position;

said projection surface including means for providing a visible display of said selectable information in the projected repertory for viewing and for transmitting a portion of the light projected onto said surface and reflected by said light reflector at said selected position for reradiation toward said detecting means in a magnitude substantially greater than other light emanating from said surface.

2. The two-way projection system of claim 1 wherein said detecting means further includes:

an array of photosensitive detectors;

means for imaging light from said selected position onto said photosensitive detector array with predetermined alignment between each detector in the array and predetermined positions of said selected position on said projection surface; and

means for sampling the photosensitive detectors in said array to determine which of said detectors is receiving illumination from said light reflector at a selected position.

3. The two-way system of claim 2 wherein:

said imaging means includes means for producing on said detector array a generally focused image of said projection surface;

said detector array includes a two dimensional matrix of said photosensitive detectors; and

said sampling means includes means for scanning the rows and columns of said matrix of detectors to provide a digital indication of the position of a detector illuminated by light from said light reflector at said selected position.

4. The two-way projection system of claim 3 wherein said scanning means further includes:

means for providing a plurality of scans of said detector array and corresponding indications of the position of an illuminated detector;

means for determining that the indicated detector during adjacent scans remains the same for a predetermined number of adjacent scans to provide a verified detector indication; and

means responsive to the verified detector indication for providing an output representation of the corresponding detector after said predetermined number of adjacent scans.

5. The two-way projection system of claim 2 wherein

said imaging means includes a mask with apertures therethrough in a two dimensional arrangement providing a pattern of light on said detector array in response to light emanating from a selected position on said projection surface; and

said detector array includes a two dimensional arrangement of detectors positioned for selective illumination by said pattern of light.

6. The two-way projection system of claim 1 wherein said projecting means further includes:

a projector containing a plurality of selectable information repertories for projection;

means for advancing said projector from one selectable repertory for projection to a different selectable repertory for projection; and

means for providing an output indication of the repertory projected from said plurality of selectable repertories.

7. The two-way projection system of claim 1 wherein said projection surface further includes:

a light diffusing coating; and

a plurality of apertures through said light diffusing coating at predetermined points thereby to more readily transmit light from said light director for radiation to said detecting means when said selected position coincides with one of said apertures.

8. The two-way projection system of claim 1 wherein said projection surface includes a Fresnel lens.

9. The two-way projection system of claim 1 further including:

a beam-splitter in the path of and transmissive to light from said projecting means to said projection surface;

said beam-splitter responding to light emanating from said projection surface to redirect the emanating light; and

means for imaging the redirected light on said detecting means.

10. The two-way projection system of claim 9 wherein said light reflector includes a retro-reflector.

11. A two-way projection system for an input terminal and providing for the display of a repertory of selectable input information and for the identification of selected input information, said system comprising:

a projection surface formed to include a surface which provides a forwardly viewable image of a rear projected information repertory and to provide substantial transmission of light from front to rear for backward emanation of said light in at least a plurality of predetermined portions;

means for rear projecting a repertory of selectable information for display on said surface;

said repertory including a plurality of information selections and selection points projected in alignment with said predetermined portions;

light director means for providing a rear emanation of light from said surface at one of said predetermined portions;

a two-dimensional array of light sensitive detectors arranged in a row and column pattern;

means for forming on said array a light pattern in response to light emanating from said one of said predetermined portions of said projection surface, said pattern activating one or more detectors;

a counter cycling through a predetermined total count with each count state designating a row and column combination;

means responsive to the count cycling of said counter for scanning said array of detectors to provide a first signal when the row and column combination designated by the count state identifies an activated detector;

means for storing the count state corresponding to said first signal;

means for comparing the stored count state for a prior first signal with the current count state of said counter to provide a second signal in response to identity in the count states compared;

means for counting sequential second signals coincident with said first signal toward a predetermined total count;

means for reinitiating the counting of said counting means prior to its predetermined total count in response to one of said first and said second signals without the other; and

means responsive to the predetermined total count of said counting means for providing an output indication to indicate that the stored count state represents input information.

12. The two-way projection system of claim 11 further including:

means responsive to said output indication, said second signal and the absence of said first signal for counting toward a further predetermined total count; and

means responsive to said further predetermined total count for removing said output indication.

13. The two-way projection system of claim 11 wherein:

said projection surface includes translucent portions for forming an image and transparent portions;

said projection means includes a random access projector for transparencies containing said repertories and means for selecting a transparency for projection;

said forming means including a lens; and

said array is a generally rectangular arrangement of detectors.

14. The two-way projection system of claim 11 wherein:

said forming means includes a mask having a pattern of angled light transmissive slits; and

said detector array includes a single row of detectors and a single column of detectors.