BG106810A - Computer input system - Google Patents

Abstract

The computer input system (CIS) is used for manual loading of data by an operator to a computer by shifting the operator's hand (25) in the space of the active zone. CIS comprises a computer and at least one input device including sources (12) and photoreceivers (13) of optical radiation, means of conversion (70) converting, reflected from the hand (25) of the operator, optical radiation, control means (71), generating control signal (92) 93) for controlling the movement of a cursor (62) on a computer display (49). CIS contains at least two operating pairs (9, 10, 11), each of them including at least one source (12) and one photoreceiver (13), fitted next to each other and optically insulated from each other, source (12) being supplied by a modulated electric signal (78, 79), means for conversion (70), including electronic active filters (74, 75) - digital or analogue, active zone, part of space, suitably oriented and at some distance, exceeding at least several times the distance between source (12) and the photoreceiver (13) of any one of the operating pairs. For each falling beam (4) from source (12) of any of the operating pairs (9, 10, 11) there is an option for reflecting from the hand (25), found in this active zone, by means of a beam (7), reflected back to the photoreceiver (13) of the same operating pair (9, 10, 11). 10 claims, 9 figures

Description

The invention relates to a computer input system (FAC) for manually entering data from an operator to a computer, by moving the operator's hand to a portion of the space constituting the active area of that FAC.

BACKGROUND OF THE INVENTION

[1] describes a light source irradiating at least two fields, a movable body (PT), partially covering both fields, a means of detecting and comparing the intensity of the two fields partially covered by PT in two mutually perpendicular directions. When the PT is moved, the ratio of the fields covered by the PT is changed, respectively, between the light intensity • · · · · · · · · · · · · · · · · · · · · · · · · · • · · · · t · · · · · · · · · · · · · · · · ·

-2 falling from each of them to the detector. [2] describes a similar device, but including a PT displaced over four fields. The disadvantage of these two structures is that the PT is mechanically coupled to the detector by being mounted underneath a prominent one therein. This reduces the ease of use. Another disadvantage is the inability to enter data by moving the PT in the three dimensions of space.

[3] describes a keyboard containing elements of the emitting and receiving elements, and a reflected beam generated by the approach of a finger to the emitting matrix triggers at least one of the photodetectors on the receiving matrix. The downside is the intricate construction and recognition in two-dimensional space only.

[4] describes a computer input system for controlling a computer display cursor by means of a point reflector attached to the body of the operator. The system includes a detector comprising a source of radiation, a scanner receiving a matrix of photodetectors, and a means for storing and comparing images. The disadvantage is the complex design of the detector due to the large distance to the reflector and the low level of the received reflected signal.

Each of [5] to [7] describes a data input device comprising several photodetectors. A PT containing reflectors or a light source is moved on a plane surface between photodetectors whose values change as they move. A processing tool retrieves information about the database being moved from each photo receiver. The disadvantage is the low resolution, the inability to recognize in the three-dimensional space, respectively the large number of photodetectors, conditioned by the requirement for sufficient recognition accuracy when necessary.

Technical nature

It is an object of the invention to provide a device enabling accurate and fast entry of operator-to-computer data related to the position and at least one operator arm or part thereof (hereinafter referred to as the 'arm') into space. This task is solved with the help of the proposed FAC. It is designed to manually input data from an operator to a computer by converting hand movements into a control signal. The CVC contains a computer and at least one input device. This introductory device includes optical radiation sources, optical radiation receivers (photodetectors), a means of conversion converting optical reflection received from the receiver by the photo receivers into two-dimensional or three-dimensional vector data related to the position of the arm in space, and a control means generating a control signal dependent on this vector data to control the movement of the cursor on a computer display. A KBS, characterized in that it comprises at least two working pairs, each of which includes at least one optical radiation source and at least one photodetector located adjacent to each other at a distance commensurate with their size. The source and the photodetector of optical radiation of each working pair are optically isolated from each other to prevent the direct radiation from entering the photodetector from the source of optical radiation of that or other working pair. The working pairs are spaced apart at least several times the distance between the source and the photodetector of any of the working pairs. It is also a feature that the optical ground cell is powered by a modulated electrical signal to improve signal-to-noise ratio and eliminate post-current fluctuations resulting from subsequent processing of the · ·

- 4 received reflected signal. In addition, the transducer includes electronic active filters, digital or analog, to reduce: the influence of ambient light and its changes; parasitic induced noises; the influence generated by the optical source of another work pair on the received useful signal. Another feature is that the CVC contains an active area, representing a certain part * of the space common to all working pairs. This core is suitably oriented and spaced from the working pairs at a distance exceeding at least several times the distance between the source and the photodetector of any of the working pairs. At the same time, for the incident beam of any working pair to the active zone, the possibility of reflection from the hand located in that active zone is created - by a reflected beam reflected back to the photodetector of the same working pair.

A KB using optical radiation is suitable, representing light from the visible or infrared range. Optical sources of light emitting diodes are also convenient. In this case, the use of photodiodes or phototransistors is appropriate as photodetectors.

In some applications, the CVC is characterized in that it contains an additional recognition means for recognizing the rapid movement of the arm in the core used to generate a signal confirming the activation of an icon indicated by the cursor on the computer display.

In some applications, a CVC is suitable, characterized in that the conversion means includes at least one additional photodetector of the same type as those used in the working pairs. This reduces the influence of ambient light, noise from the induced parasitic electromotive

-5V mains or other voltage, as well as photocurrent in the dark, characteristic of each photodetector.

A KBS construction is suitable, according to which at least the working pairs are mounted in the housing of the computer, computer display or keyboard, in which the active zone is located on or around this housing at a certain distance from it. Applications are useful in which the core comprises a surface for moving the arm in a plane, this surface being able to activate a sensor to confirm the selection of a specified icon from the computer display by pressing on that surface. In some of these applications, the surface is transparent, with at least one working pair located below it.

In other cases, the CVC is characterized by the fact that it contains a surface which is a liquid crystal computer display, which allows the hand to be moved in the plane of this display and positioned on the icons depicted on it. According to other applications involving electronic and computer game controllers, the core comprises an elastic body transparent to the optical radiation used to conveniently position the arm in the core.

A CVC containing a means of converting the movement of the arm at least by determining its position is suitable. It is advantageous for the CVC to include a means of converting the movement of the arm at least by determining its speed. According to another solution, the transducer recognizes the movement of the arm, at least by determining its acceleration. In some cases, the CVS contains radiation sources whose transmitting power varies depending on the level of the surrounding background from parasitic radiation. Other applications provide KBC, characterized in that it contains sources and receivers of · · · · · · · · · · · · · · · · · · · · · ·

-6 radiation from the millimeter or millimeter ranges. An embodiment in which the transducer or control means comprises a means for calculating movement by means of triangulapies using the signals from at least two photodetectors. In some cases, the CVC is characterized by the fact that: it calculates the movement in the first direction; calculates the movement in the second direction perpendicular to the first direction; generates output signals that depend on the calculated motion in the first and second directions. In this case, the output signal level is sequentially determined depending on the movement in the first direction and the movement in the second direction. A solution is possible in which the output signal is composed of at least two parallel signals, at least one of the parallel signals having a level determined depending on the movement in the first direction and at least one of the parallel signals having a level determined depending on the movement in the second direction . It is appropriate when a hand sliding surface is included in the core. Sometimes the surface is transparent to the incident beam and the reflected beam, and it is appropriate that it be flat. In other cases, the surface is a liquid crystal display. It is possible to combine, where this surface is a key on a computer keyboard. It is advantageous for the CVC to further comprise an electric switch that can be switched between at least a first position or a second position by the operator to enable or disable a certain possibility of the computer input system. In the presence of a real keyboard with multiple keys, the electric key can be switched by pressing a predefined key combination. In addition, the transducer recognizes the movement of the hand only when the electric switch is in the first position; in others • 4 ·· Η • 4 4 • 4 444 • · · 4 • 4 ·· e

4444

In some cases, the computer receives the control signal output only when the electrical switch is in the first position. Another suitable construction provides that at least one of the working nuts be positioned below a plane surface that is transparent. In many applications, the plane surface is transparent to the incident beam and the reflected beam. In these examples, the CVC contains a sensor that responds to pressure at any point on the plane surface, making use of a piezoelectric sensor to confirm the selection of an icon. In other cases, this is accomplished by the rapid detection of the reflected beam by the CVC, by the rapid movement of at least one of the fingers. This quick move is arbitrary, but is in the active area of the work pairs. One possible application involves the use of an imaginary keyboard located near a pocket computer, mobile phone or other small device to enter information into that device. In this case, at least one cursor is moved to the display showing an image of the imaginary keyboard, providing the ability to resize this imaginary keyboard. It is advantageous to use amplitude of, frequency, pulse-width, phase-pulse or combined modulation of optical radiation. In some cases, the working pairs include optical filters for optical separation. Another KVS solution involves incorporating at least one polarizer to polarize optical radiation.

When working, the operator moves his or her hand or part of it to the core. It allows the receiving beam to receive from each working pair and reflect the reflected beam back to each of them. In this move, the arm is positioned sequentially at different points in the plane or space of the core, thereby

• Changes the distance between her and the workforce. This causes a change in the amplitude of the signal received by each photodetector, which is a function of the degree of mean distance to the arm. The signals from the receivers are sent to the transducer, where vector data corresponding to the size and direction of the displacement are formed. The vector data enters a control that generates control signals dependent on this vector data to control the movement of the cursor on a computer display.

Advantages of the CVC described in this way are: precise and fast data entry into a computer related to the positioning of the operator arm in a plane or three-dimensional space; high accuracy of positioning and reading, achieved due to the absence of movable mechanical parts and associated flaps; universal use of the same KVS: for moving the cursor, selecting icons and typing using an imaginary keyboard, for mounting into small-sized devices where it is impossible to use another keyboard; the ability to resize such a keyboard; simultaneous use as: a complementary or replacement device for a computer mouse, a joystick, a multimedia means for drawing and sculpting in a plane or three-dimensional space; the ability to execute proportional commands in which the changed parameter changes smoothly, depending on the position of the hand in a plane or three-dimensional space; absence of congestion due to dirt or foreign objects; convenience of use due to its small size; simplified construction. This simplified design avoids the use of: sophisticated optical systems; mechanical, laser or electronic scanning; dies of emitters and receivers of optical radiation; optical histogram converters; Fri.

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-9Expression of the attached figures

FIG. 1 shows an example of the arrangement of three working pairs, conventionally depicted 9, 10, 11, arranged at the vertices of a triangle 14, which include a source 12 and photodetectors 13 of optical radiation, as well as partitions 15. They are of a material opaque to the radiation used and protect the photodetector 13 from direct radiation from the sources 12. The incident rays 4 and the reflected rays 7, respectively, and from the working pairs 9, 10 and 11 are shown.

FIG. 2 shows an example of placement of a source 12 and a photodetector 13 of optical radiation in an opaque body 17. An additional reflector 16 is shown to achieve the desired distribution of optical radiation in the core. It is possible to exchange the locations of the source 12 and the photodetector 13, which achieves the desired sensitivity distribution of the photodetector 13 in the core.

Fig. 3 shows an example of an introductory device, a constituent of the KBC. Shown is housing 1 with three working pairs 9, 10, 11 mounted therein, triangles 14. The upper part of housing 1 is open or transparent, allowing for the movement of the arm 25 and for registering this displacement. in three dimensions of Oxyz space.

Figure 4 shows an example depicting a housing 1 which includes a transparent plane surface 20 movably mounted in a housing 1 by means of three elastic supports 18 and three sensors - electrical switches 19. They are located below the transparent plane surface 20 and are actuated by a vertical force applied at any point on this surface 20.

Figure 5 shows a top view of the example of Figure 4.

- 10 Fig. 6b shows an example of an introductory device, an integral part of the FAC. It includes housing 1, working pairs 9, 10, 11 connected by cables 34 to housing 35 in which conversion certificates and controls are mounted. Additional buttons 39 and 40 are mounted to the housing 1 for additional functions. For clarity, no connecting cables of additional buttons 31, 32 to housing 35 are shown. 36, 37, 38 show the directions of incident and reflected beams. Output cable 41 connects the input device to the computer, the KBC. The ability to replace a computer mouse or joystick has been created.

Fig. 7 refers to the example of Fig. 6b and shows the distances da, db, dc between t.O at the hand of the operator, on the one hand, and points A, B, C at which the working pairs 9, 10 are located, 11, on the other hand. Point O is valid, so the distances shown da, db, dc are only relevant to it.

Fig. 8 shows an example embodiment of a PIC comprising a pocket computer (DC). A liquid crystal display 49 depicting icons 51 and a keyboard 50 is installed in front of the housing 48 of the remote control. It corresponds to an imaginary keyboard 54 located in the space in front of the remote control. A cursor 62 corresponding to the position of the arm 25 is shown. The housing includes a stand 53, and two working pairs containing emitters 12 and photodetectors 13.

Fig. 9 shows a block diagram of an exemplary introduction device constituting a KBC. It controls the movement of the cursor on a computer display, depending on the movement of the arm 25 in the plane Ohu - control signals X, Y. In addition, the input device recognizes the rapid movement of the arm 25 or part of it in the active zone as a trigger signal indicated by cursor icon - control signal B ("virtual button").

- 10 Fig. 6b shows an example of an introductory device, an integral part of the FAC. It includes housing 1, working pairs 9, 10, 11 connected by cables 34 to housing 35 in which conversion certificates and controls are mounted. Additional buttons 39 and 40 are mounted to the housing 1 for additional functions. For clarity, no connecting cables of additional buttons 31, 32 to housing 35 are shown. 36, 37, 38 show the directions of incident and reflected beams. Output cable 41 connects the input device to the PC computer. The ability to replace a computer mouse or joystick has been created.

Fig. 7 refers to the example of Fig. 6b and shows the distances da, db, dc between t.O at the hand of the operator, on the one hand, and points A, B, C at which the working pairs 9, 10 are located, 11, on the other hand. Point O is valid, so the distances shown da, db, dc are only relevant to it.

Fig. 8 shows an example embodiment of a PIC comprising a pocket computer (DC). A liquid crystal display 49 depicting icons 51 and a keyboard 50 is installed in front of the housing 48 of the remote control. It corresponds to an imaginary keyboard 54 located in the space of the front door. A cursor 62 corresponding to the position of the arm 25 is shown. The housing includes a stand 53, and two working pairs containing emitters 12 and photodetectors 13.

FIG. 9 shows a block diagram of an exemplary introduction device constituting a KBC. It controls the movement of the cursor on the computer display, depending on the movement of the arm 25 in the plane Ohu - control signals X, Y. In addition, the input device recognizes the rapid movement of the arm 25 or part of it in the core, as a trigger signal and is indicated cursor icon - control signal B ("virtual button").

Example of implementation

One embodiment of an IR operating with infrared incident and reflected beams 4, 7 containing a pocket computer is shown in FIGS. 8 and 9. The PSC includes a plastic housing 48 in which the computer and an input device are mounted. It recognizes the movement of the arm 25 in the Oxy plane, as well as the rapid movement, for example, of a finger tapping on the Ohu surface, used to confirm the selection of icon 51 or key from the display 50 on the display 49, which is an image of an imaginary keyboard 54 located in the space in front of the handheld computer (for short only - selecting icon 51). The input device comprises a converter 70 and a control 71. The converter 70 has two channels, comprising two working pairs mounted at the bottom of the housing, each of the working pairs containing an infrared LED iodine as a source of optical radiation, and infrared photo diode used as photodetector 13. Working pairs include opaque barrier 15, directing light from the LED to the photodiode. The transducer 70 includes a generator 76 for generating and supplying periodic electrical pulses 78, 79 to the light emitting diodes - source of optical radiation 12. This generator 76 is capable of clocking 77 to synchronize the operation of the entire input device. The infrared photo diodes - photodetectors 13 are connected to the inputs of preamplifiers 72, 73. They are connected to electronic band active filters, one for each of the channels 74 and 75, respectively, and the filtered and detected signals are received in devices 80 and 81. They are analog-to-digital converters 80, 81, and their output is the output of the conversion device 70 and represents vector data - size and direction,

- 12corresponding to the movement performed on x and y. Conversion device 71 comprises two devices 82, 83 for correcting the disproportion between the x and y displacements and the vector data transmitted from the outputs of the analog-to-digital converters 80, 81. The output of each of the devices 82, 83 is fed to: a device for summing 84 the digital signals from the two channels; and a device 85 for subtracting these signals. The outputs of the summation device 84 are connected to: register 86; recognition means 88 for recognizing the rapid movement of the impulse-producing arm 89 to confirm the selection of icon 51; and apparatus 90 for forming. output impulse 92 along y-axis. The outputs of the digital signal extraction device 85 are connected to: register 87; a device 91 for generating an output pulse 93 along the x-axis. The output pulses 93, 92, and 89 represent the output signals X, Y, and B of the input device and are connected to the computer and KVS to control the cursor 62 and confirm the selection of icon 51.

Application of the invention

In the considered example of FIGS. 8 and FIG. 9, two working pairs are used as light sources, infrared LEDs, are uniform and have a uniform distribution of light power in the core. Each of the photodetectors 13 of the infrared photodiodes used has a linear relationship between the illumination and the photocurrent generated by it, which is inversely proportional to the square of the doubled average distance to the arm 25. Then all possible positions of the arm 25 in the active zone generating the measured photocurrent by the photodetector 13 of one working pair form a geometric spot of points representing a hemisphere.

Example of implementation

An example of an embodiment of a KB operating with infrared incident and reflected beams 4.7 which contains a pocket computer is shown in Figures 8 and 9. The PSC includes a plastic housing 48 in which the computer and an input device are mounted. It recognizes

movement of the arm 25 in the Oxy plane, as well as rapid movement such as a finger tapping on the Ohu surface used to confirm the selection of icon 51 or key from the display keypad 49 shown on the display 49, which is an image of an imaginary keyboard 54 located in space in front of Pocket PC (for short only - select icon 51). The input device comprises a converter 70 and a control 71, the converter 70 has two channels, comprising two working pairs mounted in the lower private housing. Each of the working pairs contains an infrared LED as a source 12 of optical radiation, and infrared photo the diode used as the photoreceptor 13. The working pairs include an opaque barrier 15 to prevent direct light from the LED to the photo diode. The conversion means 70 includes a generator 7 € for generating and supplying periodic electrical impulses 78, 79 to the LEDs emitting optical radiation 12. This generator 76 is capable of delivering clock pulses 77 to synchronize the operation of the entire input device . The infrared photo diodes - photodetectors 13 are connected to the inputs of preamplifiers 72, 73. They are connected to electronic band active filters, one for each of the channels 74 and 75, respectively, and the filtered and detected signals are received in devices 80 and 81. They are analog-to-digital converters 80, 81, their output being the output of the conversion device 70 and representing vector data - size and direction,

-I ········· ··· ··· ·· ·· ·· ····

-12 corresponding to the movement performed on x and y. Conversion device 71 comprises two devices 82, 83 for correcting the disproportionality between the displacements performed and the vector data received from the outputs of the analog-to-digital converters 80, 81. The output of each of the devices 82, 83 is fed to: a device for summing 84 the digital signals from the two channels; and a device 85 for subtracting these signals. The outputs of the summation device 84 are connected to: register 86; recognition means 88 for recognizing the rapid movement of the hand producing impulse 89 for confirming the selection ia icon 51; and a device 90 for generating an output impulse 92 along the y axis. The outputs of the digital signal extraction device 85 are connected to: register 87; a device 91 for generating an output pulse 93 along the x-axis. The output pulses 93, 92, and 89 represent the output signals X, Y, and B of the input device and are connected to the PC at the cursor control 62 and confirm icon selection 51.

Application of the invention

In the considered example of FIG. 8 and 9, two working pairs are used, the light sources being infrared LEDs being the same and having a uniform distribution of light power in the core. Each of the photodetectors used, 13 infrared photodiodes, has a linear relationship between the illumination and the photocurrent generated by it, which is inversely proportional to the square of twice the average distance to the arm 25. Then all possible positions of the arm 25 in the active zone generating the measured photocurrent by the photodetector 13 of one working pair form a geometric spot of points representing a hemisphere.

- 13 Accordingly, all possible positions of the arm in the active zone, giving rise to the measured fayut (illumination) of the photodetector of the second working pair, form a geometric location of points representing the second hemisphere. The intersection of the two hemispheres is an arc of a circle, and placing the arm at any point of that arc causes the measured values of the photocurrent in the photodetectors of the two working pairs to be mentioned. This arc pierces the Ohu plane where the operator's hand is moved at a single point, so that the hand coordinates can be uniquely determined based on the measured values of the photocurrent (illumination) of each photodetector.

In the example considered, the generator produces rectangular electrical pulses 78 and 79 of frequency f which are in counter-phase. They alternatively activate the infrared LEDs of each working pair, such that when the upper emits, the lower does not emit, and vice versa. Initially, an impulse is applied to the first (eg, upper a of Fig. 9) work pair. A falling beam 25 on the arm 25 induces a reflected beam 4, which generates illumination and photocurrent in the photodetector 13 of this working pair. The current pulse is amplified in a preamplifier 72, which is connected by a circuit of a voltage differential converter. The amplified signal is fed into an analog bandpass filter 74, which amplifies only the useful signal with frequency f. The following is an analog-to-digital conversion performed in device 80. Its operation is synchronized with clock pulses with frequency a 77 generated by the generator 76. This eliminates the possibility of penetration of a parasitic signal at a time when the own LED of this operating the couple does not broadcast. In the same way, the process in the lower channel of the conversion means 70 proceeds through devices 73, 75 and 81. The two digital signals from the analog-to-digital converters 80 and 81 • 4 4 4 · 4 4 · 44 4 4 44444

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Claims (10)

1. A computer input system (CVS) for manually inputting data from an operator to a computer by converting hand movements into a control signal comprising a computer and at least one input device, which input device includes: optical radiation sources; optical radiation receivers (photodetectors); a means of conversion converting optical reflection from the operator's hand received by the photodetectors into two- or three-dimensional vector data related to the position of the hand in space; a control means generating a control signal dependent on this vector data for controlling the cursor movement on a computer display, characterized in that it contains: at least two working pairs (9, 10, 11), each comprising at least one optical radiation source (12) and at least one photodetector (13) adjacent to each other at a distance commensurate with their size, wherein the working pairs (9, 10, 11) a are spaced apart from each other at least several times the distance between the source (12) and the photodetector (13) of any of the working pairs (9, 10, 11); a source (12) and a photodetector (13) of optical radiation from each working pair (9, 10, 11), which are optically isolated from each other, to prevent direct radiation from entering the photodetector (13) from the source (12) of optical transmission of this or any other working unit; an optical radiation source (12) powered by a modulated electrical signal (78, 79) for improving signal-to-noise ratio and eliminating direct current fluctuations; · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · (70) incorporating electronic active filters (74, 75) - digital or analogue, to reduce: the influence of ambient light and its changes; parasitic induced noises; the influence caused by the source (12) of optical radiation from another operating unit on the received useful signal; an active area representing a portion of the space common to all working pairs (9, 10, 11), oriented appropriately, at a distance greater than at least several times the distance between the source (12) and the receiver (13) of any one of in which the incident beam (4) from the source (12) of any working pair (9, 10, 11) to the core is capable of being reflected by the arm (25) located in that core by a reflected beam (7) received by the photodetector (13) of the same working pair. 2. The KBS according to claim 1, characterized in that the optical radiation is a light of the imium type or infrared. A KBS according to claim 2, characterized in that the optical radiation sources (12) are LED iodine and the photodetectors (13) are photodiode or phototransistors. A KBS according to claim 1, characterized in that it contains an additional recognition means (88) for recognizing the rapid movement of the arm (25) in the active zone used to generate a signal (89) confirming the activation of the cursor specified (62) icon (50, 51) on computer display (49). 5. The KBS according to claim 1, characterized in that the conversion means (70) includes at least one additional photodetector of the same type as used in the working pairs (9, 10, 11), to reduce the influence of at least one of the following: ambient light; noise induced by parasitic electric motors with mains or other frequency; photocurrent in the dark. A KBS according to claim I, characterized in that at least the working pairs (9, 10, 11) are mounted in the housing (48) of the computer, the computer display (49) or the keyboard, wherein the core is located: on or around this enclosure at a certain distance from it. 7. KBS according to claim 1 or 6, characterized in that the active zone comprises a surface (20) for moving the arm in a plane, this surface being capable of activating a sensor (19) for confirming the selection of said icon ( 50, 51) from the computer display (49) by pressing on this surface (20). A KBS according to claim 7, characterized in that the surface (20) is transparent, with at least one working pair (9, 10, 11) disposed below it. 9. The KBS according to claim 1 or claim 7, characterized in that it comprises a surface (20) representing a liquid crystal computer display (49) for moving the arm in a plane and positioning it on depicted icons (50, 51). 10. The KBS according to claim 1, characterized in that the core comprises an elastic body transparent to the optical radiation used, intended to conveniently position the arm (25) in that core.