WO2010035093A2

WO2010035093A2 - Computer input unit suitable for use by right-handed people and left-handed people

Info

Publication number: WO2010035093A2
Application number: PCT/IB2009/006753
Authority: WO
Inventors: Alessandro Pocaterra; Alessio Grotto
Original assignee: Videotec S.P.A.
Priority date: 2008-09-29
Filing date: 2009-09-04
Publication date: 2010-04-01
Also published as: WO2010035093A3; EP2350777A2; ITTO20080710A1

Abstract

An input unit (2) for a computer (1) is described, which is adapted to be used in at least two different modes, in particular one for right-handed people and one for left-handed people. The input unit (2) comprises a plurality of keys (21) and a control unit (400) which detects when the keys (21) are pressed. Each key (21) is associated with a read code which is transmitted to the computer by the control unit (400) when the input unit (2) is operating in a first one of said two modes. The keys (21) are arranged according to a centrally symmetric configuration. When the input unit (2) is operating in the second one of said two modes, as a first key is pressed the control unit (400) will transmit the read code of a second key; the latter is the key which is symmetric to the key actually pressed with respect to the centre of symmetry of the plurality of keys.

Description

COMPUTER INPUT UNIT SUITABLE FOR USE BY RIGHT-HANDED PEOPLE AND LEFT-HANDED PEOPLE

DESCRIPTION

The present invention relates to a computer input unit according to the preamble of claim 1.

As known, in order to interact with a computer a user has to use input units through which he/she can enter data or command signals to be transferred to the computer, where they are then processed. Some examples of input units are keyboards, joysticks, jog-shuttles, mouse devises, optical pens, microphones, etc.

Most manual input units (keyboard, joysticks, mouse devises, etc.) available today have been conceived for right-handed people, though a few product lines actually exist which are dedicated to left-handed people. When a computer is equipped with an input unit for right-handed people, a left-handed user having to use that input unit will not feel comfortable at all, and will be compelled to adapt him/herself to the circumstances or to replace the input unit with another one specifically designed for left-handed people.

Notwithstanding input units can be programmed and customized to some extent, even by exchanging key positions as shown in patent US 6,650,250, the problem of creating one unit which can be comfortably used by both right-handed and left-handed people is still far from being solved.

Input units like the one disclosed by patent US 6,650,250, for example, have a fully customizable keyboard and a fixed part including a display and knobs which (during normal use) always remain on the left of the keyboard, thus getting in the way of a left-handed user operating the computer input unit. hi order to solve this problem, a number of solutions have been conceived for allowing an input unit to be used by both right-handed and left-handed people.

Patent JP4125714 discloses a computer in which the monitor and the keyboard are enclosed within the same structure. The latter has two openings, fitted with respective connectors, in which the keyboard can be inserted and connected. Depending on which opening the keyboard is connected into, the monitor output is rotated so that, by turning the whole structure, a left- handed user can have the keyboard on the left of the monitor and a right-handed user can keep the keyboard on the right without the image appearing upside-down on the monitor. This solution suffers from the drawback that the input unit has not been designed for both right-handed and left-handed people, and therefore rotating the structure does not solve the problem of an uncomfortable use of the input unit.

Patent US 5,023,438 discloses a bar code reader equipped with a display. The reader has a display and means adapted to detect whether the apparatus is being used by a left-handed person or a right-handed person. Depending of the information detected, the image on the display is turned over. This solutions has the drawback that the reader keyboard is fixed, so that a left-handed person using the reader will find an upside-down keyboard.

In the solutions proposed in JP4125714 and US 5,023,438, the keyboard remains unchanged (at both hardware and software levels), and the computer detects that the keyboard is being used by a left-handed person or a right-handed person and then changes the image displayed on the screen accordingly. These solutions do not offer the same comfort of use of the keyboard to both right-handed and left-handed people.

A different approach has been followed by patent US 5,144,302, which discloses a modular keyboard wherein different modules (each comprising a certain fixed number of keys or a trackball) can be connected to one another differently according to whether the keyboard has to be used by a right-handed person or a left-handed person.

This type of solution however suffer from the drawback that the connectors that allow the various modules to be connected to one another may get damaged over time. It is the object of the present invention to overcome the drawbacks of the computer input units known in the art. In particular, the present invention aims at providing an input unit which can be used comfortably by both right-handed and left-handed people.

These and other objects of the present invention are achieved through a computer input unit incorporating the features set out in the appended claims, which are intended as an integral part of the present description. The present invention is based upon the idea of providing a computer input unit which can be used in at least two modes, one for right-handed people and one for left-handed people. The input unit is equipped with a plurality of keys and a control unit capable of detecting when one or more keys are being pressed. Each key is associated with a read code which is transmitted to the computer by the control unit when the latter is operating in a first one of said two modes, e.g. the one for right-handed people. The keys are arranged in a centrally symmetric configuration, so that when the input unit is used in a second mode different from the first one (e.g. the one for left-handed people) and a key is pressed, the control unit will transmit to the computer the read code of that key which is symmetric to the key actually pressed. Of course, when the key pressed by the user is located at the centre of symmetry of the set of keys, then the code of that key will be transmitted, since it is symmetric to itself. With this solution, by turning the input unit by 180° about the centre of symmetry, those control devices (e.g. a joystick) which were before on the right of the keys (when viewed by a user) will then move to the left, thus becoming more comfortable for a left-handed person, while the positions of the functions associated with the keys will remain apparently unchanged for the user, hi other words, if when the joystick is on the right the key in the upper left corner is associated with a certain read code sent to the computer and interpreted by the latter as controlling a certain function, when the input unit is rotated and the joystick is moved to the left the user will be able to control the same function by pressing the key which will now be in the upper left corner. The control unit knows that it is operating in "left-handed user" mode and therefore, instead of sending the read code of the key actually pressed, it will send the read code of the key located in the lower right corner, corresponding to the one that would be pressed if the keyboard were being used in "right-handed user" mode.

Advantageously, the input unit is provided with control devices, such as a joystick or a jog- shuttle, whose movement is read by the control unit of the input unit. When an operating mode of the input unit (e.g. for right-handed people) is switched to a different mode (e.g. for left-handed people), the control unit reverses the signal sent to the computer. While in the first mode when the control device was moved in a certain direction the control unit sent to the computer a signal corresponding to a movement in that given direction, when the input unit is turned by 180° and used in a different mode the control unit sends to the computer a signal corresponding to a movement of the device in the direction opposite to the one detected, hi this way, if the control device is moved in a given direction (e.g. towards the user), the input unit will always transmit to the computer (whether used in right-handed user or left-handed user mode) a signal corresponding to a movement of the control device in the same given direction (referring to the above example, towards the user) even though, due to the rotation of the input unit, the control unit should detect that the control device has been moved in two opposite directions. Advantageously, the input unit detects the mode in which it has to operate, e.g. right-handed person or left-handed person, automatically.

Preferably, the input unit is equipped with suitable support means, such as feet, which allow the control unit to be tilted for more comfort of use. By detecting (e.g. through sensors) which support means are being used, the input unit can understand whether it is being used by a right-handed person or a left-handed person.

Alternatively, the automatic detection of the operating mode may be obtained through an accelerometer or a mercury switch detecting the slope of the input unit relative to the bearing plane.

Further objects and advantages of the present invention will become more apparent from the following description and from the annexed drawings, which are only supplied by way of non- limiting example, wherein:

- Fig. 1 shows a workstation comprising an input unit according to the present invention;

- Fig. 2 is an exploded view of the input unit of Fig. 1;

- Fig. 3 shows the end-plate of the input unit of Fig. 1; - Fig. 4 is a block diagram of an input unit according to the present invention;

- Fig. 5 is circuit diagram of the input unit of Fig. 1;

- Figs. 6a-6c show the operation of the keys of the input unit of Fig. 1;

- Figs. 7a-7c show each two sectional views of an input unit according to the present invention, the input unit being shown in said two views in two different operating modes; - Fig. 8 is a block diagram of the input unit initialization procedure;

- Fig. 9 shows a matrix of the read codes associated with the keys;

- Figs. 10-15 show different alternative solutions of input units according to the present invention.

Fig. 1 shows a workstation comprising a computer 1, an input unit 2 and a monitor 3. In the example of Fig. 1, input unit 2 is a keyboard comprising a plurality of keys 21, a joystick 22 and a jog-shuttle 23. Input unit 2 is connected to computer 1 by means of a cable 24 through which it sends and receives information. Preferably, cable 24 is a USB (Universal Serial BUS) cable; it follows that input unit 2 also receives power through cable 24. As an alternative, input unit 2 may be connected to computer 1 by means of another type of connection, e.g. a serial or wireless connection, and be powered separately, e.g. by batteries. The workstation shown in Fig. 1 is particularly suitable for video surveillance systems, where the traverse of the video cameras can be controlled by means of joystick 22 and parts of video sequences can be viewed by means of jog-shuttle 23.

In the example of Fig. 1, input unit 2 is used in a mode which is comfortable for a right- handed operator 4: in fact, joystick 22 is located on the right side for an operator 4 using the input unit while watching the monitor.

Fig. 2 is an exploded view of input unit 2 of Fig. 1.

Input unit 2 comprises a lower shell 200 and an upper shell 201, preferably made of plastic material.

Upper shell 201 has a plurality of holes 202 in which keys 21, provided with a body 203, preferably made of plastic, are inserted and can slide.

Reference numeral 204 designates the printed circuit comprising the electronics of input unit 2, in particular the control unit that allows to detect when keys 21 are pressed or the movements of joystick 22 and jog-shuttle 23. Cable 24 is a USB cable of the A-B type, connector B thereof being connected to printed circuit 204 through a connector not shown in Fig. 2. Cable 24 is secured to one of the two plastic shells (200 and 201) by means of small pins which form an anti-tear winding path such that cable 24 cannot be disconnected when pulled.

This solution is different from those known solutions wherein the connector is external to the body of the input unit (so that it can be easily disconnected accidentally), as well as from those known solutions wherein the cable is soldered to the printed circuit (and therefore cannot be replaced easily).

The presence of the internal connector in the body of the input unit allows the installer to replace the cable with another one of the same type but having a different length, easily available on the market. However, the winding path makes it difficult to extract cable 24 from its seat, thus preventing the cable from being accidentally disconnected from the input unit. A punched sheet 205 (preferably made of polycarbonate) with the key labels and a protective panel 206 (preferably made of a transparent plastic material) are removably coupled to upper plastic shell 201, e.g. through snap-in means. Punched sheet 205 may be printed by the installer in order to customize the keyboard.

Below plastic shell 200 there are feet 207 which allow input unit 2 to be tilted relative to the bearing surface thereof. When not in use, feet 207 are preferably folded into suitable housings obtained in the end-plate of shell 200.

Fig. 3 shows the end-plate of input unit 2; from this perspective, four feet 207 are visible which are arranged in pairs along two sides of the input unit, thus allowing either long side

(208 or 209) of the input unit to be raised. Four feet 207 may possibly be replaced with other support elements, such as support bars extending on two opposite sides of the input unit. In particular, if the input unit has a substantially rectangular shape, then the two support bars will be arranged parallel to the two major sides of the rectangle.

Fig. 4 is a block diagram of a preferred embodiment of an input unit according to the present invention.

The core of the system is the control unit, which in the example described below is microcontroller 400 that directly controls the operation of input unit 2. Alternatively, the control unit may be manufactured by using multiple electronic devices in communication with one another. From USB cable 24, a power circuit 401 extracts power voltage having a maximum current of

500 mA, in accordance with the specifications of USB standard.

Microcontroller 400 is also connected to a reset circuit 402 which handles the start-up process when the USB connector is plugged into a computer 1 and the input unit receives power through the USB cable. Microcontroller 400 can communicate with computer 1 through a communication channel 404 which, in the example of Fig. 4, is a USB channel.

Through channel 404, the microcontroller receives and sends data, e.g. it sends to the computer the read codes (or scan codes) of the keys being pressed.

For this purpose, the microcontroller 400 is connected to the matrix 405. The latter consists of the whole set of electric lines and connections carrying the pressure signals from keys 21 to microcontroller 400. Said lines and connections are arranged according to a row-column scheme as described below with reference to Fig. 5, which shows the circuit diagram of key matrix 405 and the connection thereof to microcontroller 400.

Key matrix 405 comprises a plurality of lines R1,R2,...RM, used for reading the matrix rows, and a plurality of lines C1,C2,...CN, used for reading the matrix columns. Each key 21 is essentially equivalent to a switch 501 with a diode 502 connected in series, and is connected to microcontroller 400 through a row line and a column line. Diode 502 is used for preventing ghosting, i.e. that phenomenon according to which, when certain keys are pressed simultaneously, the signals generated on the matrix interfere with one another and the microcontroller detects the actuation of keys that have not been pressed. The use of diodes also allows for multi-key handling: any key combination can be recognized correctly. At any simultaneous change of state of multiple keys (pressed or released), the input unit sends several individual messages to the computer, one for each switched key. The lines making up the rows and columns of key matrix 405 are connected to different inputs ICl,...ICN, IRl,...IRM of microcontroller 400. Figs. 6a and 6b show the actuation of a key 21 of input unit 2. Key 21 is provided in the form of an internally hollow cylindrical rubber piece 203. At the base of key 21 there is a circular crown 600 made of conductive material, and so sized as to lie over two concentric conductive crowns provided on the printed circuit. One crown is connected to a row line of the key matrix, whereas the other crown is connected to a column line of the key matrix. When the key is pressed (as shown by the arrow in Fig. 6b), crown 600 shorts the row and column lines, so that microcontroller 400 detects that the key has been pressed. Internally, microcontroller 400 comprises a scanner module 4001 capable of scanning the lines afferent thereto in order to detect when one or more keys 21 are being pressed. The scanner handles a matrix of M rows by N columns, where M and N are chosen according to the desired number and arrangement of keys.

Although the scanner can detect pressure on MxN keys (e.g. 9x8=72 keys), it is not necessary that all keys are installed.

By changing the number of rubber keys 203, it is therefore possible to customize the keyboard of input unit 2. Punched sheet 205 allows to cover those areas of the printed circuit which correspond to unavailable keys, thus making them invisible to the operator. Plastic panel 206, which is transparent and has a shape similar to that of the punched sheet, prevents any pressure exerted by the user onto areas corresponding to holes in upper shell 201 where there are no keys from deforming or damaging punched sheet 205 with the labels.

Preferably, as shown in Figs. 6a-6c, each key 21 has an independent LED (Light Emitting Diode) 601 handled by LED array 406. The LED is preferably located inside the circular crowns forming the key detection zone. This provides optimum centering of the LED relative to key 21; it is however possible to use one or more LEDs in different positions, e.g. outside the circular crowns forming the key detection zone.

According to messages received by microcontroller 400 through the USB channel 404 the LED may be turned on, turned off or may be blinking. The LEDs are controlled directly by the microcontroller, or alternatively by a set of serial-parallel shift register integrated circuits, should the number of available control pins not be sufficient.

The on and off signals are supplied to the LEDs by means of lines arranged on the side of printed circuit 204 opposite to the LED's emission side. In this manner, the LED control lines will not interfere with the lines of key matrix 405.

The light emitted by the LED crosses rubber body 203 of key 21 as shown by the arrows in

Fig. 6c, and then scatters into the outer environment.

The LEDs of uninstalled keys can be used for indicating special events. To this end, punched sheet 205 comprises a transparent area arranged over these LEDs. The input unit is equipped with a two-axis or three-axis joystick 22 and a jog-shuttle 23. The joystick is directly connected to the ADCs (Analog to Digital Converters) of microcontroller

400. On the contrary, the jog-shuttle requires a control electronics 407, e.g. an encoder, capable of reading the movement of the jog-dial and shuttle-ring (which make up the jog- shuttle) and of transferring the detected data to microcontroller 400. When instructed to do so by computer 1 , microcontroller 400 may activate a warning buzzer

408.

Input unit 2 may optionally be fitted with a graphic display 409; microcontroller 400 will thus be able to display information associated with the pressed keys.

When a key or a key combination is pressed, microcontroller 400 will read memory 403 and retrieve the information (e.g. text strings and/or images) to be displayed on display 409.

Advantageously, input unit 2 can receive information to be displayed on display 409 from computer 1. Said information is received through communication channel 404 (a USB channel in the example of Fig. 4) and is then displayed on display 409 under control of microcontroller 400.

Two examples of input units equipped with a graphic display are shown in Figs. 10 and 15. In the example of Fig. 4, input unit 2 is also provided with a biometric sensor, in particular a fingerprint reader 410, which allows to verify the identity of the user of the input unit. As an alternative, the biometric sensor may recognize other parameters, such as voice, retina shape, etc. Using a biometric sensor is particularly advantageous for video surveillance stations, where it is important to ensure that unauthorized people cannot take control of the system.

If the biometric sensor provides voice recognition, unconventional control functions will also be possible, such as voice control of the input unit. Because a biometric sensor with voice recognition includes a microphone, the latter can be used in operation in order to issue voice commands to the input unit. Such commands will be interpreted by microcontroller 400 as key actuations or additional special commands.

This solution appears to be particularly advantageous for video surveillance systems, where handling a plurality of video cameras can be a complex task. Through a voice command it will be possible to turn on a video camera, e.g. by issuing the "CAMERA ON" command followed by a number identifying that video camera (e.g. "5"), also expressed as a voice command or by pressing a corresponding key.

In the example of Fig. 4, input unit 2 is equipped with a slope indicator 411 which allows microcontroller 400 to know the orientation of the input unit and therefore to automatically detect the operating mode of input unit 2. The slope indicator is preferably provided as a mercury switch or an accelerometer, and allows to automatically recognize the orientation of the keyboard (straight or reversed).

In the example of Fig. 7a, input unit 2 is equipped with a mercury switch 701 mounted on printed circuit 204.

Mercury switch 701 allows to recognize a slope greater than a certain characteristic angle (called differential angle), and is of the open/closed type: when a certain slope angle relative to a reference axis is exceeded, the state of the switch changes from closed to open and vice versa. This switch therefore allows to recognize two states: input unit in a first "normal" position (corresponding, for example, to the operating mode for right-handed people), and input unit in a position other than "normal" (e.g. flat or reversed, corresponding to a second operating mode for left-handed people). Angle α of mercury switch 701 relative to the horizontal plane, in fact, allows to determine the slope of the input unit: depending on the value of α, the switch will return an open contact signal (Fig.7a on the left) or a closed contact signal (Fig.7a on the right) to the microcontroller. Thus, microcontroller 400 can deduce whether the input unit is being used in "left-handed user" mode or in "right-handed user" mode. In fact, when the input unit is used with the joystick on the operator's right a first pair of feet is used for raising the input unit, whereas when the joystick is kept on the operator's left a second pair of feet is used instead, opposite to the first one, thus obtaining an opposite tilt.

As an alternative to a mercury switch, it is also possible to use an accelerometer as shown in Fig. 7b, which is a sectional view of input unit 2 used in two different modes, one for right- handed people and one for left-handed people. Accelerometer 702, being of the three-axis type, recognizes the spatial direction of the force of gravity G.

Gravity vector G is subdivided into three orthogonal vectorial components X, Y (not shown) and Z, where X is a component which is parallel to the plane of printed circuit 204 in which the accelerometer lies. The latter returns three analog values dependent on the module and on the direction of each vector. By analyzing these values, microcontroller 400 determines with great accuracy the inclination in space of the accelerometer and, consequently, of the input unit. Depending on the direction of component X, microcontroller 400 knows the tilt of input unit 2 and detects the mode in which it is being used, i.e. for either right-handed or left-handed people.

As an alternative, a two-axis accelerometer may also be used which, though not providing the module of vector Z, still allows to detect component X and hence to determine the slope of the input unit. Another possible method for automatically detecting the operating mode of the input unit is shown in Fig. 7c, which is a sectional view of the input unit used in two different modes, one for right-handed people and one for left-handed people. On printed circuit 204 there are proximity sensors 703 a and 703 b, preferably being of the on/off type in order to keep production costs low. Sensors 703 a and 703 b are preferably at least two and may be capacitive, magnetic, inductive, etc. It is however possible to use a single proximity sensor which detects the state of one foot. In any case, the proximity sensor recognizes the proximity of a target based on magnetic field variations or on fluctuations of an emitted radiation reflected by the target.

At least two feet 207, which are to fold near respective proximity sensors, are provided with a target (704a, 704b) intended for being detected by one of sensors 703a and 703b.

The signal returned by the sensor pair, once analyzed by a suitable control electronics, allows the microcontroller to obtain the orientation of the input unit: depending on the slope, one foot will be folded and the other will be unfolded, as shown in Fig. 7c.

When the input unit is connected to a computer 1, an initialization procedure is carried out as described below with reference to Fig. 8.

As soon as the input unit is connected to a computer (step 800), microcontroller 400 is reset by th reset circuit 402 (step 801). After the hardware and software have been initialized (step

802), microcontroller 400 checks for the presence of one or more signals for starting the configuration of the input unit (step 803). Such signals may be generated by the user by pressing one or more keys, or else be generated by one or more sensors which, as explained above with reference to Figs. 7a-7c, allow to detect whether the input unit is being used in right-handed user mode or left-handed user mode.

If the microcontroller detects one or more configuration signals, then a configuration procedure dependent on the detected signals will start (step 804) as described below.

Otherwise, if no configuration signals are detected at start-up, microcontroller 400 will read

(step 805) the configuration stored in rewritable memory 403. When the input unit is started for the first time (step 806) and no configuration is stored in memory 403, then microcontroller 400 will write a default configuration into the memory 403

(step 807).

The microcontroller will thus start the configuration procedure by reading the configuration parameters from memory 403 (step 808). Preferably but not necessarily, the input unit can communicate with the computer according to several protocols, thus being more versatile, hi the preferred solution, the input unit can communicate with computer 1 in "virtual com port", "joystick emulation" or "mouse emulation" modes.

While the "virtual com port" mode allows a full native utilization of the input unit, the "joystick emulation" and "mouse emulation" modes provide backward compatibility for applications installed in the computer which already use standard USB Human Interface Device control systems such as joysticks and mouse devises.

Based on the configuration stored in memory 403, microcontroller 400 will then set USB channel 404 (step 809) in accordance with one of the available communication protocols. The configuration procedure also takes into account the operating mode of the input unit (for right-handed people or left-handed people).

According to the slope signal or to the key pressed by the user when the input unit is connected, the microcontroller determines if the latter is being used in right-handed user mode or left-handed user mode, and sets a flag into an appropriate memory area. Said flag will then determine the output of the input unit in response to a key being pressed in operation. The configuration procedure is preferably specific for the number and position of the available keys, and may use blinking LEDs or the display, if present. For example, according to the key being pressed, the microcontroller will decide which type of configuration must be started. Thus, there will be one key for setting up the input unit as a "virtual com port" in right-handed user mode, another key for setting up the input unit as a "virtual com port" in left-handed user mode, and so on. At most, there may be as many configuration keys as the number of possible configurations.

Of course, if the input unit is equipped with slope or proximity sensors as described with reference to Figs. 7a-7c, then the signals generated by these sensors will be used by microcontroller 400 in combination with the signals received from key matrix 405. hi other words, it will be possible to provide one key for instructing microcontroller 400 about the communication protocol to be used by the input unit for communicating with the PC, while the operating mode will be detected automatically by the tilt sensor.

The configuration procedure may be started upon verification that the operator is an authorized user. Said verification may be obtained through biometric sensor 410 or by requiring the user to enter a password or press a sequence of keys.

Once the input unit has been configured, it will be ready for communicating with computer 1 ; in particular, microcontroller 400 can provide the computer's operating system with the information necessary for recognizing and installing the input unit. When installation is completed (step 810), the input unit is fully operational. When in operation, the microcontroller executes a cyclic algorithm in order to check if the positions of the keys have changed and if the joystick and the jog-shuttle have been moved. If the position of a key has changed (e.g. it has been pressed or released), this variation is communicated to the computer. Likewise, if the joystick or the jog-shuttle have been moved, then the corresponding information is sent to computer 1. In order to decide which piece of information is to be sent to the computer, microcontroller 400 checks which mode (right-hander or left-hander) was chosen during the input unit configuration procedure.

If the right-handed user mode was selected, then upon pressing a key occupying a certain position (expressed as row/column) of the key matrix, the microcontroller will transmit to the computer a read code (or scan code) preferably identifying the position of that key on the key matrix. Said code is preferably made up of two juxtaposed numbers: the first number corresponds to the number of the row acted upon by the key, whereas the second number corresponds to the number of the column acted upon by the key.

Upon pressing a key occupying the first row and the first column of the key matrix (i.e. the key in the position (1,1) of the key matrix), the microcontroller will send code '11' to computer 1.

Fig. 9 shows the read code matrix, i.e. the matrix of the codes sent by microcontroller 400 to the computer as keys 21 of the input unit are pressed when the latter is being used in right- handed user mode, hi the example of Fig. 9 it has been assumed that the key matrix includes seventy-two elements (8x9 matrix), corresponding to a read code matrix with seventy-two elements. hi the preferred embodiment, the read code matrix described above is not stored in any memory area, being only the result of a logic operation executed by microcontroller 400. The microcontroller is programmed at firmware level in a manner such that it scans the lines forming the rows and columns of the key matrix by internally implementing the functions of scanner module 4001. This is done by reading the voltages being present at inputs Rl... RM and C 1... CN. When the microcontroller detects a signal at inputs IRl and IC 1 and detects that it is operating in right-handed user mode, then it will generate numerical code '11', which can then be sent to computer 1.

On the contrary, if the microcontroller detects that the input unit is being used in left-handed user mode, then it will send to the computer the read code of that key which is symmetrical to the one actually pressed.

This is achieved by the microcontroller by using the following algorithm: the first element of the code to be transmitted (row) is given by: number of rows of key matrix (M) plus one, minus the row number of the pressed key, the second element of the code to be transmitted (column) is given by: number of columns of the key matrix (N) plus one, minus the column number of the pressed key.

Assuming, for example, an 8x9 key matrix like the one shown in the example of Fig. 9, if the key located in the position (1,1) of the key matrix is pressed, then the read code sent to the computer by the microcontroller 400 will be the numerical code '89': the first element being calculated as 8+1-1=8, and the second element being calculated as 9+1-1=9. Alternatively, another function that allows to return the code of the key being symmetrical to the one actually pressed is the following:

- a preset value equal to the sum of the read codes of the keys occupying the positions (1,1) and (M₃N) of an MxN key matrix is first calculated;

- the read code to be returned is calculated by subtracting the read code of the pressed key from the previously calculated preset value.

If, for example, the key in the position (1,1) is pressed, the code '11' is first calculated as if the input unit were operating in right-handed user mode, and then the preset value is obtained which, with reference to the example of Fig. 9, is equal to 11+89=100. The code to be transmitted is finally calculated as: 100-11=89. Of course, the preset value to be used in this embodiment may be calculated once during the input unit configuration procedure, or else it may be stored in a memory area during the production process or simply be set as a constant of the calculation algorithm executed by microcontroller 400. Since keys 21 are arranged in a centrally symmetric configuration, when the keyboard is turned by 180° and the joystick is moved from the operator's right side to the operator's left side, the key configuration will appear unchanged to the user. Any labels affixed near the keys will appear reversed, but a removable punched sheet 205, protected by transparent plastic panel 206, can be lifted and turned by 180° as well, thus orienting the key labels in a manner such that they become readable by the user. Although in the preferred embodiment described above the numerical code generated by microcontroller 400 is sent to the computer as a read code, according to an alternative solution said code may be used as a pointer to a memory area of the input unit (e.g. of memory 403) storing other codes or 'labels' consisting of alphanumerical strings.

In this latter embodiment, such codes or labels form the read code which is then transmitted. Instead of sending the numerical code generated by its own internal algorithm, the microcontroller will thus transmit to computer 1 the codes or labels contained in the aforementioned memory area. The use of labels makes it easier to program applications to be executed on the computer, but requires a larger memory area than the preferred solution previously described. As far as joystick 22 is concerned, when the input unit is used in left-handed user mode microcontroller 400 detects a movement of the joystick and sends to computer 1 a piece of information relating to a movement in the direction opposite to the one detected. This is due to the fact that, when the input unit is rotated by 180° in order to move the joystick from the operator's right hand to the operator's left hand, the joystick is upside-down and the microcontroller detects a movement which is opposite to the one desired by the operator. This problem does not affect the jog-shuttle, since even when the input unit is rotated there will be no change in the direction of rotation of the jog-shuttle, and therefore in the output of encoder 407. As far as the jog-shuttle is concerned, when the input unit is reversed microcontroller 400 will keep sending the same signal to computer 1, regardless of the active mode. It is clear that many changes may be made to the above-described preferred solution by those skilled in the art.

For example, the above-described electronic components may be combined or arranged differently without modifying the functions and features of the input unit according to the present invention. Likewise, the keys may be arranged in different configurations, provided that such configurations still ensure central symmetry. Some examples of alternative examples of centrally symmetric arrangements are shown in Figs. 10 to 15, wherein different aesthetical solutions are presented.

In the solution of Fig. 10, input unit 2 is equipped with a buzzer 408 which, as aforementioned, under control of microcontroller 400 can generate noise in response to signals sent by computer 1. In this solution, the input unit has a graphic display 409 located at the centre of keys 21, which are arranged on all four sides of the display, thus surrounding it. In the solution of Fig. 11, input unit 2 is equipped with a fingerprint reader 410. The solution of Fig. 15 appears to be particularly advantageous because it does not require the use of a removable punched sheet to be rotated when the operating mode of the input unit is changed. It comprises a graphic display 409 and eight keys 21 arranged on two rows on both sides of the display. The number of keys is not to be understood as limiting. In the solution of Fig. 15, the labels of keys 21 are not printed on a punched sheet removably applied to the upper shell of the input unit (as shown in Fig. 2), but are obtained through images displayed on display 409. In the solution of Fig. 15, within the display area there are eight areas 4090 alongside the eight keys.

In areas 4090, images or characters describing the function of the adjacent key are displayed (under control of microcontroller 400). When the keyboard is rotated, e.g. for being used in left-handed user mode, microprocessor 400 detects the mode change and rotates the images on the display. In particular, the images on the display are changed in a manner such that each key is associated with the image previously associated with the key symmetrical thereto, with reference to the centre of symmetry of the keys, when the input unit was being used in the other mode, e.g. the right- handed user mode. An effect equivalent to the rotation of the punched sheet of Fig. 2 is thus obtained. Of course, further variants of the solution of Fig. 15 may still be obtained through aesthetic modifications, e.g. by distributing the two rows of keys over circular sectors arranged on both sides of the display. This will still allow the displayed labels to be visually associated with the various keys, but the aesthetic appearance will be different.

Claims

CLAlMS

1. Input unit (2) for a computer (1), adapted to be used in at least two different modes, in particular one for right-handed people and one for left-handed people, comprising a plurality of keys (21), and a control unit (400) adapted to detect when a key (21) of said plurality is being pressed, and wherein each key (21) of said plurality is associated with a read code which is transmitted to said computer (1) by said control unit (400) when the input unit (2) is operating in a first one of said two modes, characterized in that said plurality of keys (21) is arranged according to a centrally symmetric configuration, and that, when said input unit (2) is operating in the second one of said two modes, as a first key is pressed said control unit (400) is adapted to transmit the read code of a second key, said second key being symmetric to the key being pressed with respect to the centre of symmetry of said plurality of keys.

2. Input unit according to claim 1, wherein each key acts upon one pair of lines (Rl-RM, Cl- CM), and wherein the set of lines acted upon by said plurality of keys (21) is a part of a key matrix (405) in which said lines correspond to rows and columns of the key matrix (405), and wherein the read code of a key is a numerical code obtained by juxtaposing the number of the row acted upon by the key in front of the number of the column acted upon by the key.

3. Input unit according to claim 2, wherein, when the input unit is operating in said second mode, the read code to be transmitted is obtained by juxtaposing a first number to a second number, said first number being obtained by subtracting the row number of the key being pressed from the total number of rows of the key matrix (405), and said second number being obtained by subtracting the column number of the key being pressed from the total number of columns of the key matrix (405).

4. Input unit according to claim 2, wherein the key matrix (405) is an MxN matrix, where M and N are positive integers, and wherein, when the input unit (2) is operating in said second mode, the read code to be transmitted is obtained by subtracting the read code of the key being pressed from a predefined value, said predefined value being obtained as a sum of the read codes of the keys occupying the positions (1,1) and (M,N) of the key matrix (405).

5. Input unit according to claim 1, wherein each key acts upon one pair of lines (Rl-RM, Cl- CM), and wherein the set of lines acted upon by said plurality of keys (21) is a part of a key matrix (405) in which said lines correspond to rows and columns of the key matrix (405), and wherein the read code of a key is contained in a memory area (403) of the input unit (2), and wherein the control unit (400) reads said read code by using a numerical code as a pointer to said memory area, and wherein, in said first mode, said numerical code is obtained by juxtaposing the number of the row acted upon by the key in front of the number of the column acted upon by the key.

6. Input unit according to claim 5, wherein, when the input unit is operating in said second mode, said numerical code is obtained by juxtaposing a first number to a second number, where said first number is obtained by subtracting the row number of the key being pressed from the total number of rows of the key matrix (405), and where said second number is obtained by subtracting the column number of the key being pressed from the total number of columns of the key matrix (405).

7. Input unit according to claim 5, wherein the key matrix (405) is an MxN matrix, where M and N are positive integers, and wherein, when the input unit is operating in said second mode, said numerical code is obtained by subtracting the read code of the key being pressed from a predefined value, said predefined value being obtained as a sum of the read codes of the keys occupying the positions (1,1) and (M,N) of the key matrix (405).

8. Input unit according to any of the preceding claims, wherein said control unit (400) is adapted to automatically detect the mode in which said input unit is being used.

9. Input unit according to claim 8, further comprising a tilt sensor (701, 702) adapted to detect the tilt of said input unit relative to a plane, said tilt sensor being connected to the control unit

(400) in a manner such that said control unit can determine the operating mode of the input unit (2) based on a piece of information received from said tilt sensor.

10. Input unit according to claim 9, wherein said tilt sensor comprises an accelerometer (702).

11. Input unit according to claim 8, further comprising: movable support means (207) adapted to take at least two positions and to raise said input unit from a bearing plane, and at least one proximity sensor (703) adapted to detect a position of at least one of said support means (207), said proximity sensor being connected to the control unit (400) in a manner such that said control unit (400) can determine the operating mode of the input unit (2) based on a piece of information received from said proximity sensor (703).

12. Input unit according to any of the preceding claims, wherein said plurality of keys (21) are arranged on at least one side of a graphic display (409), wherein areas matching the keys (21) are obtained within the graphic display (409), wherein the control unit (400) is adapted to display images or characters within said areas, and wherein the control unit (400) is adapted to change the images displayed in said areas when it detects that the operating mode of the input unit has changed, in particular by assigning to one of said areas the image which was contained in the symmetric area with respect to the centre of symmetry of the keys when the input unit was used in the other mode which was active prior to the change.

13. Input unit according to any of the preceding claims, wherein said control unit (400) is adapted to switch to an input unit (2) configuration mode when said input unit (2) is connected to a computer (1), and wherein said input unit (2) comprises at least one key that, when pressed in configuration mode, determines at least one configuration parameter of the input unit (2).

14. Input unit according to anyone of the preceding claims, wherein the input unit (2) is adapted to communicate with said computer (1) through a plurality of communication protocols.

15. Input unit according to anyone of the preceding claims, further comprising a cable (24) for connecting the input unit (2) to the computer (1), wherein the cable (24) is connected to the input unit (2) through a connector and is secured to a shell (200,201) of the input unit (2) by means of small pins which form a winding path such that the cable (24) cannot be disconnected when pulled.