CONVERSION DEVICE

Abstract: The invention relates to a device for converting a value of a quantity expressed in a datum system into a corresponding value of the quantity in another system, comprising means for calculating, on the basis of the value in the datum system, the corresponding value in the other system, means connected to the calculating means for simultaneously displaying the corresponding values in the different systems and operating means connected to the calculating means and/or the display means for causing stepwise variation of the displayed values. The calculating means may be adapted for converting the value in the datum system into the corresponding value in the other system in accordance with a fixed relation. The display means may take the form of a display screen on which is defined a number of display areas corresponding with the number of systems to be displayed. The operating means may further be adapted for scrolling successive values of the quantity along each display area and may be operable in two directions, for causing the displayed values to increase or decrease.

Description: CONVERSION DEVICE (73) The invention relates to a device for converting a value of a quantity expressed in a datum system into a corresponding value of the quantity in at least one other system. Such conversions are of great importance in practice . A known example of converting the value of a quantity from a datum system into another system is the conversion of amounts which are expressed in a person's own currency unit into corresponding amounts in a foreign currency unit or vice versa. These types of calculation are becoming of increasing importance in daily life with the increasing globalization of the economy and the growing interest for foreign travel. Furthermore, the replacement in the short term of the national currencies of a number of European countries by a common currency unit is also expected to result in many calculation operations. In addition, the conversion of physical quantities such as measures, weights and temperatures from for instance the Anglo-Saxon system into the international system of SI units is also a task which frequently occurs in practice. For the performing of such calculations use has mostly been made heretofore of general calculators or computers. However, because these have to be suitable for many diverse calculations, they are not very suitable for performing simple standard calculations in accordance with a fixed formula, since the operation thereof is often relatively complicated. Particularly for users with little or no experience in the use of calculators or electronic equipment in general, this complicated operation often represents a threshold. Standard calculations on such general calculators moreover require a disproportionate amount of time as a result of the necessity of repeatedly entering determined recurring factors or operations . The invention therefore has for its object to provide a device of the above described type with which in rapid and simple manner the value of a quantity expressed in a first system can be converted into the corresponding value in another system. According to the invention such a device is characterized by means for calculating, on the basis of the value in the datum system, the corresponding value in the or each other system, means connected to the calculating means for simultaneously displaying the corresponding values in the different systems and operating means connected to the calculating means and/or the display means for causing stepwise variation of the displayed values. Such a device, which does not have to have the plurality of input means known from the conventional calculator devices, is simple to operate and is therefore also suitable for use by people who are not familiar with the use of electronic equipment. The calculating means are preferably adapted to convert the value in the datum system into the corresponding value in the or each other system in accordance with a fixed relation. By thus making the conversion device suitable for only one or a small number of standard calculations, the operation thereof is both quicker and simpler than that of a conventional calculator. In a very simple embodiment of the device according to the invention the calculating means comprise at least one table in which is stored a series of values of the quantity in different systems . Calculations thus in fact no longer have to be performed, and values only have to be looked up in tables . In order to enable clear display of the value of the relevant quantity in both the datum system and the other system, the display means take the form of one or more display screens on which is defined a number of display areas corresponding with the number of systems for display. When the operating means are adapted for scrolling of successive values of the quantity along each display area, the sought value of the quantity in the datum system and the value in the other system corresponding therewith can be brought to the screen very rapidly. The operating means can herein advantageously be operated in two directions, for causing the displayed values to increase or decrease. The operating means can comprise one or more push keys, but could also be formed by a wheel button. The operating means are preferably adapted to adjust the speed of the stepwise variation of the displayed values in the case of prolonged and/or repeated operation thereof. In this manner a rapid search can be made for a desired value range by accelerating the stepwise variation, whereafter by once again slowing down the stepwise variation a precise search can be made within this range for the correct value. An easily operated conversion device is obtained when the operating means are adapted to perform a stepwise adjustment. The adjustment is herein advantageously an acceleration. It is thus possible to move to the desired value range . When in addition the operating means act in two opposite directions and are further adapted to slow down the stepwise variation when the operating direction is changed, the progress of the datum value and therewith the calculated value can as it were be "slowed down". The operating means can advantageously also be adapted to hold the displayed values during a prolonged change of the operating direction. The operating means thus function as it were as "emergency brake". The adjustment preferably amounts to one order of magnitude at a time . Thus is ensured that at each adjustment a more or less significant digit of the values shown in the screens changes at the same speed at which the preceding digit was varied. In order to limit as much as possible the power required by the conversion device, since the continuous calculations in the case of stepwise variation of the values require much energy, the calculating means are preferably adapted, subject to the speed of the stepwise variation, to disregard at least the least significant digit of the value of the quantity in each system. By thus not taking the least significant digit into account in every calculation a considerable saving on the calculating effort is achieved. Because in practice this least significant digit varies so rapidly that this is not detectable with the human eye, the display of the values is not essentially influenced hereby. The calculating means can herein advantageously be adapted to adjust the number of significant digits in the calculation at each adjustment of the speed of the stepwise variation. Because rounding-off differences will usually occur during conversion and these can be a particular problem when converting amounts of money, the calculating means in the conversion device according to the invention are preferably adapted to generate a signal when the value of the quantity expressed in the system with the largest basic unit corresponds within accepted rounding-off rules with the value of the quantity in the other system. This signal can be displayed optically by for instance the display means . According to another aspect of the present invention the operating means are preferably adapted to vary per digit the displayed value in at least the datum system. In this manner a value for converting in the datum system can be inputted in roughly the same manner as in a conventional calculator, i.e. digit by digit, whereby operation of the device is still also simple to learn for people who have relatively little experience in handling electronic equipment . The operating means can herein advantageously be operated in two directions for selecting a more or less significant digit, so that the user can as it were "jump back and forth" in the value for inputting and can adjust each digit thereof at any random moment . In order to enable use of the conversion device with the same ease for calculations both from and to the datum system, the operating means are advantageously adapted to interchange the datum system and the or each other system. The invention also has for its object to provide a conversion device of the described type wherein no battery has to be used. According to yet another aspect of the invention this is achieved by power supply means in the form of at least one solar cell connected to the calculating means and the display means. The presence of one or more solar cells renders a battery superfluous, whereby the device can take a simpler and less expensive form and the environmental impact resulting from discarded batteries is moreover reduced. The invention will now be elucidated on the basis of a number of embodiments, wherein reference is made to the annexed drawing, in which: Fig. 1 shows a block diagram of the different components of a conversion device according to the invention, Fig. 2 is a front view of a first embodiment of this conversion device, Fig. 3 shows a front view of a second embodiment thereof, Fig. 4A and 4B show the value of a quantity in the case of slow and rapid variation thereof, Fig. 5 is a perspective front view of a third embodiment of the conversion device according to the invention, and Fig. 6A and 6B show schematically the selection of another digit for adjusting. o A device 1 for converting a value of a quantity expressed in a datum system into a corresponding value of the quantity in at least one other system (fig. 1) is provided with electronic means 2 for calculating, on the basis of the value in the datum system, the corresponding value in the or each other system, means 3 connected to calculating means 2 for simultaneously displaying the corresponding values in the different systems and operating means 4 connected to calculating means 2 for causing stepwise variation of the displayed values 5, 6. Stepwise variation herein means that the value of the least significant digit of the numerical value is increased or decreased by one unit at a time . When the value in the datum system is varied stepwise, the associated value in the other system, in this example the value 6 expressed in guilders, will also change. This change, which is calculated by micro-controller 7, will proceed more quickly or, on the contrary, more slowly depending on the ratio between the two systems . In the shown example the value 6 in guilders will change slightly more than twice as rapidly as the value 5 in Euros, since the conversion rate at this moment amounts to about € 1 = / 2.20. A fixed relation is used for conversion of the value of the quantity in the datum system into the corresponding value in the other system. This fixed relation between the values can be stored in the electronics, for instance in a ROM memory, during the production of conversion device 1. Instead of a fixed conversion relation, a table can also be included in the ROM memory having therein for a series of values of the quantity in the datum system the corresponding values in the other system. When device 1 has to be suitable for converting the value from the datum system into a plurality of other systems, a corresponding number of conversion relations or tables is of course stored in the memory . 7 In the shown embodiment calculating means 2 form part of a so-called micro-controller 7 by which not only the calculations are performed but by which display means 3 , in this case in the form of an LCD screen 8 with two separate display areas 9, 10, are also actuated. Microcontroller 7 and LCD screen 8 are fed from a power source 11, for instance a battery or a solar cell 11 (fig. 3) . The different electronic components are accommodated in a housing 21 which can take a very compact form and have dimensions in the order of a few centimetres. Housing 21 is provided inter alia with operating means 4, in the shown embodiment in the form of two push keys 22, 23 (fig. 2) . These operating means or keys 22, 23 are connected to two contacts of micro-controller 7. By pressing one of these keys 22, 23 and keeping it pressed in, successive values of the quantity in both systems scroll along the display areas 9, 10 in the display screen. Once the value being searched for has appeared in display area 9 the relevant key 22 or 23 can be released, whereafter the associated value of the quantity in the other system can be read in the other display area 10. The direction in which the values are scrolled, i.e. the increase or decrease of the displayed values, is controlled by pressing the correct key, wherein the "-" key represents decreasing values, while the "+" key represents increasing values. In the shown embodiment device 1 is suitable for converting the value of the quantity from the datum system into a plurality of other systems to be selected by the user, and comprises a selection key 24. By pressing this key or holding it pressed in, a series of different conversion relations or tables can be run through, one of which can be selected by releasing selection key 24 when a relevant designation appears in display area 10. Device 1 can thus be used for instance to convert the value of a datum currency, for instance the Euro, into a plurality of national currencies, such as the German mark, the British pound or the guilder. It 8 would also be possible in this manner to select conversion of for instance temperatures expressed in degrees Fahrenheit into degrees Celsius or Kelvin as desired by the user. The systems used can herein be designated with an accepted symbol in display areas 9, 10. When device 1 is only suitable for a single type of conversion, the designations of the systems used can also be arranged on housing 21, in the vicinity of the relevant display areas 9, 10. Conversion device 1 can be switched on and off by means of an on/off button 25. If desired, this key could also be omitted and the device could be switched on by operating one of the other operating keys 22, 23 or 24, wherein device 1 could then switch itself off when no operations are performed for a pre-programmed period. Instead of the shown push keys, the operating means could otherwise also take the form of a wheel button or thumb wheel. A desired value can likewise be placed herewith in rapid an accurate manner in one of the display areas 9, 10. In a second embodiment of the conversion device the operating means 4 comprise only a single direction key 12 (fig. 3) which is movable, in this case tiltable, to two sides and thus operates as required one of the two carbon contacts of micro-controller 7. Operating means 4 further comprise a reset key or "zero" key 13, which actuates a single contact of micro-controller 7 and simultaneously functions to switch on the device. Switch-off of device 1 takes place automatically under the control of micro- controller 7 when device 1 is not operated for a determined time. Micro-controller 7 is programmed in this case such that when the "+" side of direction key 12 is pressed the value of the quantity in the datum system is increased stepwise, while this value is decreased stepwise when the "-" key is pressed. In order to be able to reach a desired value within a reasonable period of time, micro-controller 7 is programmed such that when direction key 12 is pressed 9 repeatedly or is held pressed in, the speed at which the value increases or decreases is adjusted, in particular increased. It is thus possible to "leaf" through the values increasingly rapidly until the desired value is approached. Micro-controller 7 is then further programmed herein such that pressing key 12 in the other direction results in the speed at which the value changes being reduced. It is therefore possible as it were to thus "brake", whereby the desired value can be approached precisely and overshooting the value can be avoided. Holding key 12 pressed in longer in the opposite direction will then even result in the value being held. For the desired value 5 in the datum system the corresponding value 6 in the other system can then be read on screen 8. In the shown embodiment micro-controller 7 is programmed such that acceleration or deceleration can be performed in stepwise manner. Device 1 therefore has a number of discrete variation speeds . In order to enhance ease of operation the difference between two successive speeds is one order of magnitude at a time, i.e. a factor of ten. Thus is achieved that during acceleration or deceleration the following more or less significant digit of the value is varied each time at the same speed as the digit varied at that moment. Thus for instance if in the datum position the least significant digit 14 of the value 5 designating the hundredths is increased or decreased by two units per second, depending on the direction indicated by key 12, the following significant digit 15 designating the tenths is then likewise varied by two units per second in the following "acceleration" . The changing speed is hereby readily predictable and controllable for a user. The acceleration or deceleration can herein have as many steps as there are significant digits, in the shown example therefore five. Suitable programming of micro-controller 7 further makes it possible that when the "+" or "-" of key 12 is pressed once briefly, for instance for only a few tenths 10 of a second, the least significant digit is increased or decreased by one unit. The desired value can thus be adjusted very precisely. Since each time the value in the datum system is varied the value in the other system is simultaneously calculated and displayed, the device requires a relatively large amount of energy. This is a problem, particularly if as in the shown embodiment use is made exclusively of one or more solar cells 11 for power supply. Micro-controller 7 is therefore programmed such that during conversion of the value from the datum system only those calculations are performed which are visible for the user. In practice this entails that a part of the less significant digits is disregarded during the conversion as long as the value in the datum system is varied relatively rapidly (fig. 4B) . Only when the rate of change decreases are these less significant digits also included once again in the calculation (fig. 4A) . Because in the case of rapid variation of the value, for instance when the tens 17 or hundreds 18 are increased or decreased by two units per second, the change of the tenths 15 or hundredths 14 is no longer visible to the human eye, "freezing" of these digits, for instance by constantly showing a "0" or an "8", is not perceived by the user as irritating. As stated, key 13 functions as reset key or "zero" key. When this key is pressed, both the displayed values 5, 6 are cleared and only zeros appear in the two display windows 9, 10. The value in the system with the smallest basic unit otherwise also runs on to "000.00" after passing "999.99", wherein the other value is therefore also reset to zero. In similar manner a jump can be made via the value zero from the "top" to the value "999.99". Any desired value can thus be reached quickly. Because rounding-off differences will always occur when converting the value 5 in the datum system to the value 6 in the other system, it is important to know at which moment two displayed values can actually be 11 accepted as mutually equivalent in accordance with official agreements. This is of course always the case for the value expressed in the system with the smallest basic unit, in this case the guilder, since this is displayed the most precisely. The value as expressed in the system with the largest basic unit is on the other hand not always unambiguous . When for instance the value € 0.00 is displayed on screen 9, screen 10 can display a value / 0.00, but with further stepwise variation the value 5 in Euros will first remain unchanged, while the value 6 in guilders will jump to / 0.01, since 1 cent is after all less than 0.5 Eurocen . Micro-controller 7 is therefore programmed such that at the moment the values no longer vary it generates a signal to display means 3 when the indicated value in one of the two systems may indeed be regarded as the equivalent of the value in the other system in accordance with officially accepted rounding-off rules. This signal results in the display of a special symbol, in the shown embodiment an arrow 19, 20 which points from the one to the other value 5, 6. Arrow 20 will in principle always be actuated because the conversion from the system with the smallest basic unit (the guilder) to the system with the largest basic unit (the Euro) is always unequivocal and therefore correct, while arrow 19 will only be shown with some of the displayed values. In a third embodiment of conversion device 1, which in respect of its method of operation displays more similarities with conventional calculators than the two above described variants, operating means 4 are adapted to vary per digit the displayed value in the datum unit . For this purpose the single operating key 12 (fig. 5) is movable not just in two but in four directions and co- acts therefore with four contacts of micro-controller 7. By pressing the left or right-hand side of key 12, designated in the example with the symbols " *■<" and "►", a more or less significant digit can be selected which is then indicated in display area 9 by a pointer symbol 26 12 (fig. 6A, 6B) . When the upper or lower side of key 12 ( » + ■■ or "-") is then pressed, the value of the thus selected digit will be increased respectively decreased stepwise. Operating means 4 can herein be adapted such that pressing key 12 once results in an increase or decrease by a single unit, while holding the key pressed in results in the value increasing or decreasing by several units per second. The variation in the value remains limited however to the selected digit. If during increasing the value "9" is reached, the value then jumps back to "0" without the value of the following significant digit being increased. The value in the other system does however change in the usual manner when the value in the datum system is varied. Thus, by successively selecting hundredths, tenths, units, tens and hundreds (in the case of a five digit display) using the "V and ' ■ ► ■■ side of key 12, and subsequently finding the correct values for each digit using the "+" and "-", a desired value in the datum system can eventually be set on display area 9, the equivalent of which in the other system then appears simultaneously in the other display area 10. As stated, this manner of inputting a value closely resembles the use of conventional calculators, whereby this variant is very suitable for users with relatively little experience of electronic equipment . In order to enable use of this variant of the device both for converting values from the datum system to the other system and for calculating values from another system back to the datum system, operating means 4 are also adapted in the shown embodiment to interchange the two systems . For this purpose reset key 13 and operating key 12 then have to be pressed simultaneously. The currency symbols "/" and " ■ €." , which are both displayed in display windows 9, 10, then change places and the values in both windows are also reset to zero. The conversion device according to the invention thus makes it possible in exceptionally simple manner, 13 starting from the known value of a quantity in a determined system, to determine the corresponding value of this same quantity in another system. Owing to the simplicity of operation the device is particularly suitable for use by people who have little experience with electronic equipment. Moreover, as a result of its small number of options, the device can be embodied very compactly and provides very many possibilities for an attractive and ergonomically responsible design. Because the device can be manufactured at low cost, it is also very suitable for use as promotional article, for instance by financial institutions. Although the device is described above with reference to an embodiment, it is not limited thereto. Many modifications and variations can be envisaged within the scope of the invention. Instead of a single screen divided into two display areas, two separate screens could for instance also be used. In addition, the number of display areas or screens could be greater than two if the value of a quantity has to be displayed in more than two different systems. It is for instance possible to envisage display of the value of an amount in a person's own currency unit and in two other important currency units, such as for instance the dollar and the euro, or display of a net amount, a gross amount and the corresponding VAT. Other options can also be envisaged for adjusting the speed at which the displayed values are varied. The keys could for instance be embodied not just for pressing but also for sliding. Simultaneously pressing and sliding to one side of one of the keys would then result in a higher speed of "scrolling" of the values than merely pressing the key. The scope of the invention is therefore determined solely by the appended claims.

Claims: 14 CLAIMS 1. Device for converting a value of a quantity expressed in a datum system into a corresponding value of the quantity in at least one other system, characterized by means for calculating, on the basis of the value in the datum system, the corresponding value in the or each other system, means connected to the calculating means for simultaneously displaying the corresponding values in the different systems and operating means connected to the calculating means and/or the display means for causing stepwise variation of the displayed values. 2. Conversion device as claimed in claim 1, characterized in that the calculating means are adapted to convert the value in the datum system into the corresponding value in the or each other system in accordance with a fixed relation. 3. Conversion device as claimed in claim 1 or 2 , characterized in that the calculating means comprise at least one table in which is stored a series of values of the quantity in different systems . 4. Conversion device as claimed in any of the foregoing claims, characterized in that the display means take the form of one or more display screens on which is defined a number of display areas corresponding with the number of systems for display. 5. Conversion device as claimed in claim 4, characterized in that the operating means are adapted for scrolling successive values of the quantity along each display area. 6. Conversion device as claimed in claim 5, characterized in that the operating means can be operated in two directions, for causing the displayed values to increase or decrease . 7. Conversion device as claimed in claim 5 or 6 , characterized in that the operating means comprise at least one push key. 15 8. Conversion device as claimed in claim 5 or 6 , characterized in that the operating means comprise at least one wheel button. 9. Conversion device as claimed in any of the claims 5-8, characterized in that the operating means are adapted to adjust the speed of the stepwise variation of the displayed values in the case of prolonged and/or repeated operation thereof . 10. Conversion device as claimed in claim 9, characterized in that the operating means are adapted to perform a stepwise adjustment. 11. Conversion device as claimed in claim 9 or 10, characterized in that the adjustment is an acceleration. 12. Conversion device as claimed in claim 6 and in any of the claims 9-11, characterized in that the operating means are adapted to slow down the stepwise variation when the operating direction is changed. 13. Conversion device as claimed in claim 12, characterized in that the operating means are adapted to hold the displayed values during a prolonged change of the operating direction. 14. Conversion device as claimed in any of the claims 9-13, characterized in that the adjustment amounts to one order of magnitude at a time. 15. Conversion device as claimed in any of the claims 9-14, characterized in that the calculating means are adapted, subject to the speed of the stepwise variation, to disregard at least the least significant digit of the value of the quantity in each system. 16. Conversion device as claimed in claim 15, characterized in that the calculating means are adapted to adjust the number of significant digits in the calculation at each adjustment of the speed of the stepwise variation. 17. Conversion device as claimed in any of the foregoing claims, characterized in that the calculating means are adapted to generate a signal when the value of the quantity expressed in the system with the largest 16 basic unit corresponds within accepted rounding-off rules with the value of the quantity in the other system. 18. Conversion device as claimed in any of the claims 5-17, characterized in that the operating means are adapted to vary per digit the displayed value in at least the datum system. 19. Conversion device as claimed in claim 18, characterized in that the operating means can be operated in two directions for selecting a more or less significant digit. 20. Conversion device as claimed in claim 18 or 19, characterized in that the operating means are adapted to interchange the datum system and the or each other system. 21. Conversion device as claimed in any of the foregoing claims, characterized by power supply means in the form of at least one solar cell connected to the calculating means and the display means.

Inventors: CHRISTIAANS CORNELIS HENDRIKUS, LAMBREGTS MARKUS JOZEF, MAREE JOSEPHUS EDUARDUS MARIA, CHRISTIAANS, CORNELIS, HENDRIKUS, LAMBREGTS, MARKUS, JOZEF, MAREE, JOSEPHUS, EDUARDUS, MARIA
Applicants: CHRISTIAANS CORNELIS HENDRIKUS, LAMBREGTS MARKUS JOZEF, MAREE JOSEPHUS EDUARDUS MARIA, CHRISTIAANS, CORNELIS, HENDRIKUS, LAMBREGTS, MARKUS, JOZEF, MAREE, JOSEPHUS, EDUARDUS, MARIA
Application year: 1998
Main classification: G06F15
IPC codes: G06F15