Classifications

• • H—ELECTRICITY
  • H03—ELECTRONIC CIRCUITRY
  • H03K—PULSE TECHNIQUE
  • H03K17/00—Electronic switching or gating, i.e. not by contact-making and –breaking
  • H03K17/94—Electronic switching or gating, i.e. not by contact-making and –breaking characterised by the way in which the control signals are generated
  • H03K17/96—Touch switches
  • H03K17/9627—Optical touch switches
  • H03K17/9629—Optical touch switches using a plurality of detectors, e.g. keyboard
• • H—ELECTRICITY
  • H03—ELECTRONIC CIRCUITRY
  • H03K—PULSE TECHNIQUE
  • H03K17/00—Electronic switching or gating, i.e. not by contact-making and –breaking
  • H03K17/94—Electronic switching or gating, i.e. not by contact-making and –breaking characterised by the way in which the control signals are generated
  • H03K17/96—Touch switches
  • H03K17/9627—Optical touch switches
  • H03K17/9631—Optical touch switches using a light source as part of the switch
• • H—ELECTRICITY
  • H03—ELECTRONIC CIRCUITRY
  • H03K—PULSE TECHNIQUE
  • H03K17/00—Electronic switching or gating, i.e. not by contact-making and –breaking
  • H03K17/94—Electronic switching or gating, i.e. not by contact-making and –breaking characterised by the way in which the control signals are generated
  • H03K17/965—Switches controlled by moving an element forming part of the switch
  • H03K17/968—Switches controlled by moving an element forming part of the switch using opto-electronic devices
  • H03K17/969—Switches controlled by moving an element forming part of the switch using opto-electronic devices having a plurality of control members, e.g. keyboard
• • D—TEXTILES; PAPER
  • D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
  • D06F—LAUNDERING, DRYING, IRONING, PRESSING OR FOLDING TEXTILE ARTICLES
  • D06F34/00—Details of control systems for washing machines, washer-dryers or laundry dryers
  • D06F34/28—Arrangements for program selection, e.g. control panels therefor; Arrangements for indicating program parameters, e.g. the selected program or its progress
  • D06F34/32—Arrangements for program selection, e.g. control panels therefor; Arrangements for indicating program parameters, e.g. the selected program or its progress characterised by graphical features, e.g. touchscreens
• • H—ELECTRICITY
  • H03—ELECTRONIC CIRCUITRY
  • H03K—PULSE TECHNIQUE
  • H03K2217/00—Indexing scheme related to electronic switching or gating, i.e. not by contact-making or -breaking covered by H03K17/00
  • H03K2217/94—Indexing scheme related to electronic switching or gating, i.e. not by contact-making or -breaking covered by H03K17/00 characterised by the way in which the control signal is generated
  • H03K2217/96—Touch switches
  • H03K2217/96066—Thumbwheel, potentiometer, scrollbar or slider simulation by touch switch

Definitions

• the present invention relates to an arrangement for keyboards which exhibit a surface area in the form of a prism divided up into control fields, each of which is allocated a control function and is intended to be contacted at the desired respective control func ⁇ tion by a surface such as the surface, of a finger tip, thereby causing a deflection of light, which is produced in the field, in relation to the luminous flux in the prism when there is no contact with the surface, said variation in the luminous flux being supplied to a light-detecting sensor by means of which an adequate command signal is produced.
• Keyboards containing a number of control functions are used for the control of different apparatuses and instruments.
• apparatuses with which such keyboards are used include program-controlled apparatuses such as washing machines and dishwashers in which by means of the keyboard an operating program is determined by selecting various components, machine tools in which various operating programs can be selected, and instruments for the production of a certain sequence, a sequence of characters- in typewriters and computers and a sequence of notes in musical instruments. It is assumed in this context that the keyboard arrangement is based on electrical functions.
• a keyboard of this kind will be of complex desigri comprising a lar e number of moving parts such as keys, electric switches and line branches.
• One possibility for simplification, at least in the mechanical sense, has however arisen in the form of so- caUed touch-sensitive keys, which do not have moving parts and which react to the contact of a finger upon a plate.
• the conductivity of the finger or its presence is utilized for this purpose as a conducting body in an oscillating circuit.
• Swedish Patent No. 7613597-9 publication No. 402 394
• Said Patent Specification proposes the utilization for this purpose of the variation in the reflection within a prism, which can be produced if a body is pressed into full contact against any of the surfaces of the prism.
• the object of the present invention is to propose an arrange ⁇ ment for keyboards for a plurality of control functions, by means of .which the number of elements required can be reduced considerably.
• a particular concern of the invention in this respect is to achieve the aforementioned object by an arrangement which utilizes the said optoelectronic principle in order to provide the control function.
• a further object of the invention is t' permit the elimination of the influence from certain interference sources, such as periodic signals from the surroundings.
• the object of the invention is achieved by means of an arrange ⁇ ment which is characterised in that a control arrangement is so arranged as to produce by means of transmitting elements a signal specific to each field and capable of being detected from the luminous flux signals from other fields, in that preferably a single element or a small number of elements fewer in " number than the number of fields is/are arranged as the sensor element, and in that a signal processing arrangement is also so arranged as to select the signal received from the sensor element in accordance with the specific signal characteristics of the transmitting elements and as to transmit an adequate control signal for each field in accordance with said selection, wherein the keyboard operates in a manner known in itself in accordance with the optoelectric principle.
• Fig. 1 shows by way of example the optoelectronic system referred to by way of introduction
• Fig. 2 shows an external view of a keyboard in accordance with the first embodiment of the invention
• Fig. 3 shows an internal view of the keyboard in accordance with Fig. 2, this view also providing a connection diagram at the same time
• Fig. 4 shows a top view of the second embodiment
• Fig. 5 shows a .top view of the third embodiment
• Fig. 1 shows by way of example the optoelectronic system referred to by way of introduction
• Fig. 3 shows an internal view of the keyboard in accordance with Fig. 2, this view also providing a connection diagram at the same time
• Fig. 4 shows a top view of the second embodiment
• Fig. 5 shows a .top view of the third embodiment
• Fig. 1 shows by way of example the optoelectronic system referred to by way of introduction
• Fig. 2 shows an external view of a keyboard in accordance with the first embodiment of the invention
• FIG. 6 shows an external view of a part of a keyboard in accordance with the fourth embodiment
• Fig. 7 shows a section along Line VIV-VII in Fig. 6
• Fig. 8 shows a sectioned view of the fifth embodiment
• Fig. 9 shows a' perspective view of the sixth embodiment
• Figs. 10-12 show a front view of the same embodiment in three ⁇ 'different types of application
• Figs. 13 and 14 show a. timing diagram for the operation of the arrangement in two different variants. Description of the Preferred Embodiments:
• an optoelectronic keyboard means of the previously mentioned kind is shown in Fig. 1.
• This is described in Swedish Patent Specification No. 7613597-9, to which US-PS 4 254 333 and GB Patent Specification No. 1 600 556 correspond.
• the basic arrange ⁇ ment can be used in a variety of ways to produce a keyboard. Its outside is formed by the outer surface 1 of a glass sheet 2 .
• the other surface 3 of the glass sheet is provided with a light-proof coating 4 with a number of windows beneath which are arranged glass prisms 5 in optical contact with the glass sheet.
• each and every one of which is exposed to a beam of light 6 from a light-emitting ele ⁇ ment 7, such as a light-emitting diode, which receives power from a power supply arrangement 8.
• a light-emitting ele ⁇ ment 7 such as a light-emitting diode
• Adjacent to each prism ⁇ there is arranged a photo-sensitive element 9,such as a photo-diode,which is connected to a signal processing arrangement 10.
• a photo-sensitive element 9 such as a photo-diode
• Fig. 2 shows a view of a keyboard 15 consisting of a glass plate 16 with a number of indicating areas 17 which bear designations 1.8 with the symbols A-J for the purpose of identifying certain control functions
• a light-sensitive element 19 for example a photodiode
• a signal processing means for example a microprocessor with an as ⁇ sociated power supply arrangement, for example a battery, which to ⁇ gether form a unit 20.
• the light-sensitive element 19 is disposed to discriminate to a very nigh degree against light sources other than those which are to influence the element, such as the light-emitting element 21 , the level of interference is low.
• the signal level can also be ker.i low in this way, and no problems are encountered in distinguishing the deflection of. light which is utilized in accordance with the foregoing in the invention. In the event of extremely difficult external lighting conditions being encountered, additional discrimination can be achieved through a special signal processing technique, which is described later. Certain electrical circuits are also shown in the Figures.
• Beneath the glass plate 16 are further elements, and these are shown in Fig. 3. They consist of a number of light-emitting ele ⁇ ments 21, for example light-emitting diodes. They correspond in number to the number of fields 17 , and each is situated beneath its own field. Also shown in Fig. 3 are the light-sensitive element 19 , the electronic unit 20 , shown here in the form of a microprocessor 22 , and a power supply battery 23 .
• Fig. 3 also constitutes a wiring diagram, it is evident from this Figure that the light-emitting diodes 21 are separately connected to the microprocessor 22 and that the light-sensitive element 19 is also connected to same. Also shown are a number of circuits 24 intended for the transmission of signal impulses to those organs which are to be controlled from the keyboard.
• the keyboard can be installed in a washing machine, for example, in which case the various command fields represent different wash programmes. In a case such as this the signal circuits 24 are routed to the programmer of the machine for the purpose of causing it to execute the selected program.
• the various component parts of the arrangement that they shall be so executed as to permit the aforementioned optoelectronic function to be achieved.
• the light-emitting elements 21 shall be so arranged as to transmit their radiation into the glass plate 16 from its rear side, which is opposite the side on which the marking fields 17 are actuated by the pressure of a finger.
• the light-sensitive element 19 is positioned at the edgt of the glass sheet with an air gap to accommodate the radiation which is reflected totally within the sheet upon the respective marking field 17 being touched.
• a single light-sensitive element is a preferred embod ment, it may be appropriate to provide a number of light-sensitive elements, especially in the case of large keyboards.
• the sheet does not contain individual prisms, but acts in its entirety as a single prism with a number of functions intended to produce total reflection within the glass sheet as soon as any of the marking fields 17 is touched.
• the glass sheet 2 is best provided with a non-translucent coating in those areas where ⁇ t is wished to prevent secondary radiation into the sheet from external light sources.
• Fig. 2 shows how the fields 17 are clearly separated from each other and are arranged in rows; ten fields are shown here. This is suitable where the on/off position for a number of functions is to be selected. A different arrangement may be preferable for other control modes.
• Fig. 4 shows an arrangement intended to replace a so-called joy-stick.
• a joy-stick is generally used to select different degrees of two functions, for example elevation and lateral displacement, or speed and direction.
• a glass plate- 26 exhibits within a marked area 27 a very large number of contact fields arranged in horizontal and vertical rows, each of which has a corresponding light-emitting element 28 on the underside of the sheet.
• An arrow 29 is used to indicate that a movement in an upward sense will produce an increase in speed from zero
• an arrow 30 is used to indicate that sideways movements will produce changes in direction from straight ahead to left- and right-hand turns respectively.
• a vehicle can thus be controlled with regard to its speed and direction of travel by moving the finger tip in different directions within the field.
• Fig. 5 shows an arrangement which is suitable for causing a change in direction.
• a glass plate 31 On a glass plate 31 is marked a circular, ring-shaped area 32 beneath which there are arranged in t . ⁇ form of a ring a number of light-emitting elements 33 .
• An arrow 34 indicates that if a contact element, for example the finger tip, is moved in a clockwise sense within the circular, annular field 32, then a variation of a function will be achieved.
• the arrangement may be suitably applied to the adjustment of a means to different rotational positions.
• a typical application is in an antenna rotator.
• the .light-emitting elements are seen from the front side of the sheet. Accordingly they- can be used for marking the locations of the contact fields and alsu for indicating occupied control positions and waiting modes, etc.
• commands are given simply by pressing an element, preferably the finger tip, against the corresponding area on the glass plate.
• Some other element may be used, if so desired, and this is necessary if it is to be possible to give commands with a gloved hand.
• the element in this case must provide total contact with the surface of the glass sheet, which can be achieved by the use of soft rubber, for example.
• Fig. 6 shows part of a keyboard 36 which forms the keyboard of a typewriter. Shown in Fig. 6 are a number of keys 37 contained in openings 38 in a hard plate 39. As may be appre ⁇ ciated from Fig. 7 the keys 37 form projections on a plate 40 made from an elastic material which is optically light-coloured under the radiation used. This plate is retained by the aforementioned plate 39 and by a subjacent plate 41 , which is also provided with openings 42 through which there extend projections 43 in an opposite direction to those of the keys 37 .
• a glass sheet 44 with an upper surface 45 and a lower surface 46 Facing these projections is a glass sheet 44 with an upper surface 45 and a lower surface 46 .
• the outer surface 47 of the projection 43 will exhibit a distance to the surface 45 of the glass sheet 44 .
• the surface 47 will be forced into contact with the surface 45 of the glass sheet thanks to the elasticity of the material in the plate 40 . This can be facilitated in the manner shown if the keys 37 and the projections 43 are connected to the rest of the plate by means of indentations. Since the material in the plate 40 with the projections 43 is in the form of an elastic material, the aforementioned ' total contact will be achieved with the surface 45 of the glass sheet 44 .
• the glass sheet 44 is in turn mounted in a housing 48 in which a number of light-emitting elements such as light-emitting diodes 49 are situated in positions opposite the projections 43.
• a light-sensitive element 50 is arranged at the edge of the glass sheet. Means for a power supply and for signal processing are also provided in this design.
• FIG. 8 Shown in Fig. 8 is a further simplified form of a keyboard comprising keys capable of being depressed.
• the keyboard means in accordance with Fig. 8 has as its casing a box 60 (shown only by its edge part) intended to enclose the electronic apparatus.
• a projecting edge 61 of the box 60 is enclosed by a cover 62 of elastic material, the main part 63 of which forms the front side of the means.
• the main part 63 is provided with raised parts 64 which form the 'keys'.
• With the help of the edge 65 of the cover 62 which is attached to the box 60 , there is also attached a glass sheet 66 and a hard plate 67 containing holes 68 .
• the glass sheet 66 is included in the previously described manner in the optoelectronic means.
• the hard plate holds the cover 62 at a distance from the glass sheet. Its raised parts 64 can b:e forced down through the holes 68 , each of which is positioned directly in line with a raised part 64 . The raised parts will then reach the surface of- the glass sheet and will provide the specified function.
• the light produced at each control field is provided by jneans of a light source arranged at each field, preferably in the form of a light-emitting diode. It is possible as an alternative, however, to utilize a travelling light beam from one or more light sources. The light beam is in this case required to sweep over the prism so rapidly that the inertia of the eye will cause it to see the fields as if they were all lit simultaneously. Since the beam is present in each field for a specific part of the time of its sweeping cycle, the opportunity is provided for selecting those light signals which are obtained from the fields when they are touched for the purposes of giving commands.
• FIG. 9 An embodiment based on this principle is illustrated in Fig. 9.
• a cathode ray tube 70 with an electron gun 71 There is present opposite the electron gun a prism in the form of a glass sheet 72 .
• This glass sheet is so arranged as to be lit by the cathode ray tube,e'ther by constituting the image screen of the tube 70 or by the glass sheet being mounted in front of the image screen.
• a light detector 73 At the edge of the glass sheet and separated from it hy a narrow air gap there is arranged a light detector 73 , as already described; see Fig. 2 and the associated descriptive text.
• the glass sheet 72 constitutes the control panel of the arrangement, and its control fields are formed by light fields 74 produced by electron beams.
• the means is connected to a control means which produces a sweeping movement for the electron beam, during which it is lit and extinguished in such a way that different images can be created.
• a control means capable of detecting the field from which a signal received by the light detector 73 'originates.
• control means This possibility for the creation of light images on the glass sheet 72 is utilized in order to create the control fields 74 .
• the appropriate actuation of the control means enables various configurations to be constructed, in this way producing a variable control panel.
• Figs. 1D-12 The manner in which this can be used is shown in Figs. 1D-12. It is possible to imagine that one has a computer terminal via which tickets can be ordered. The terminal is equipped with a control panel of the kind described here. By indicating that one wishes to buy tickets, a control image in accordance with Fig. 10 can be produced on which various types of ticket are shown. It is assumed for this purpose that *T* indicates theatre tickets. By touching the field in question marked 'T', that is to say the field 75 in Fig. 10, the control means will be caused to be switched so that the electron beam instead constructs the configuration in accordance with Fig. 11. Following the indication that one wishes to buy theatre tickets, there will now appear a choice of indications for different theatres.
• This embodiment is described as incorporating a cathode ray tube, which is a commonly encountered means for the creation of light images.
• the idea of utilizing the optoelectronic phenomenon which is fundamental to the invention and the characteristic feature of the invention of detecting in this way individual signals deflected from one and the same prism can also be applied in conjunction with other means for the construction of images. It is thus conceivable to utilize it in conjunction with image screens which make use of LC technology, or with image screens which make use of a large number of light sources, such as the light board type.
• a simple projection means which moves a beam of light from one control field to another control field at a certain rate can also be utilized. Displays both in colour and black-and-white can also be used.
• the desired command function is achieved by detecting the position on the glass sheet of the contact element, that is to say the finger tip or the projection from the keyboard (Figs. 8-9). This is achieved by means of the light which is deflected on contact being made, so that the receiver, that is to say the light-sensitive element, is actuated. However, the receiver is unable to detect from which field the light was deflected to the receiver. The distance between each light field and the receiver cannot be used on its own to provide signals which can be distinguished with any degree of reliability.
• the substance of the invention is that the different light fields should be identified for the purpose of detecting which of them has been used, in the following manner. For this purpose the operation of the embodiments in accordance with Figs. 1-8 is described first:
• the aforementioned signal processing means preferably in the fo'm of a microprocessor, is so arranged as to transmit an .ndividual activation signal to each and every one of the light-emitting elements. It is also evident from Fig. 3 how each and every one of these is connected via an individual circuit to the signal processing means 20 .
• the means is also so executed as to select the different signals arriving from the light-receiving element and which correspond to the signal transmitted by the light-emitting element in question when its light was deflected to the light-receiving element. It is possible to determine from this selection of the signals the Light-emitting element at which contact was established, and the signal processing means will transmit in " accordance with this the pre-determined, adequate command signal.
• Fig. 13 in the form of a diagram is a time displacement between the signals.
• Each and every one of the curves A-F indicates the signal processing for the different fields A-F , as shown in Fig. 2.
• the fields may be said to represent contact paths.
• the unbroken -lines indicate light signals from the light-emitting elements, and. the broken lines indicate periods during which individual contact paths are open for actuation from the light-receiving element.
• the light-emitting element corresponding to the field A a flash of light at 52 , curve A in Fig. 13.
• the signal processing means is receptive to the influence of a special contact path for a signal from the light-receiving element during a period 53 .
• Said contact path is so arranged that activation by means of a light pulse during the period 53 will produce a signal in the command circuit corresponding to the control function A .
• the light-emitting element at the contact field B will receive a light pulse during the period 54 , and within the same period or a slightly longer period, the corresponding contact path will be responsive to an impulse from the light-receiving element; see the period 55 .
• Fig. 14 shows how the light pulse can be divided up into a number of subsidiary pulses 56 , some ⁇ of .which are present within the activation area 57 for the contact path in question.
• the signal processing means is so arranged in this respect as to be activated only by a signal having a certain pre-determined frequency. Signals having a different frequency willl accordingly not produce a command signal, even if they occur during the respective receptive periods.
• an arrangement in ac ⁇ cordance with the optoelectronic principle described here is in it ⁇ self relatively insensitive to light from the surroundings,although under certain specific circumstances the risk of interference with the operation of the arrangement may arise.
• the surround ⁇ ing light is usually either of a uniform nature, since daylight does not vary in accordance with any particular frequency, or, in the case of electric light, flashing in time with the mains frequency. By choosing a frequency at a certain distance from the mains frequency, it is possible to select from both daylight and -from electric light the light which is given off by the emitt ⁇ ing elements.
• the" individual light-emitting elements can be caused to give off light at a frequency specific to each e-lement.
• the signal processing means shall be so equipped in this case as tr transmit the command signals in accordance with the frequency received, which also indicates that the corresponding field has been touched.
• types of signal coding other than the use of di erent fre ⁇ quencies.
• the signal processing means is sensitive* during the period for which the light pulse is transmitted/ to the influence of a specific 'gate', which is so arranged as to admit a command signal to that control organ which corresponds to the field in question when a light pulse is received by the light-sensitive element. If, on the other hand, the field is not actuated, then the light pulse will never reach the light-sensitive element, and no corresponding command signal will be allowed to pass.
• the light-emitting elements are used to mark certain operations,for example the fact that a certain position has been occupied, then the light-emitting element in question can be allowed to remain lit fo.r longer periods between the identifying light pulses. If the sequence of signals is sufficiently rapid, this may be perceived by the eye as a continuous light capable of being seen from the front side of the keyboard. The possibility is also afforded of arranging separate light-emitting elements beneath the plate for the purpose of marking certain operations. If, in this case, these differ from a common code system, then they will have no effect on the command function. This will be the case, for example, if they emit a continuous light whilst the 'command transmitters' flash at a certain frequency; compare Fig. 13 and the associated description.
• the position of the field of contact is compared with the position of a component which is to be operated, for example ' the rotational position ofan antenna. Adjustment the -takes place until the latter po ⁇ sition corresponds to the former.
• the invention permits the use of extremely complex control panels, including in consumer products where the cost is of great w ⁇ ortance. Furthermore, the special advantages of the optoelectronic system, that is to say its reliable operation and its high degree of insensitivity to environmental influences, can be utilized even in complicated keyboards with a large number of control functions.
• So-called binary searching can be used in order further to increase the opportunities for separating a Large number of fields and in so doing shortening the search period. This involves searching over large fields, which are reduced after each search until the actual control field has been identified by a process of elimination. Searching of this kind reduces the search operations within the searching cycle and in this way ' shortens the search period. The more complicated signal processing which is required presents no difficulties if modern microprocessors are used.
• search fields A-J are shown here. Searching can proceed in such a way that the first four fields are searched first as a single unit. If this reveals that none of the fields is being touched, then the next three fields are searched as a unit. If any of these fields is found to be being touched, then two of these fields must be searched as a unit. If either of these fields is found to be being touched, then a further search of one field will be required. If this field is found to be being touched, then the field which is being actuated will have been identified, and if it is found not to be being touched, then the other field of the two fields which have been searched will be the one which is being touched.
• any of the first four fields is found to have been touched, then two of these fields will be searched. If neither of these is found to have been touched, then one of the remaining fields will be searched, and the one of these two fields which has been touched will then be determined .in the manner indicated above. It is always possible in this way to ⁇ determine which of ten fields has been touched by the use of a search cycle which involves three searches, or four searches in unfavourable cases. A separate search of each field would, on the other h?nd, involve making ten searches.
• each Light field 74 (Fig.- 9) will be built up from a number of lines, each of which constitutes a portion of a line over the entire width of the image screen. This means that, in the case of each light field which is touched for a period having a duration extending over a number of complete compositions of the image (a complete image is usually produced in 1/25 - 1/3G of a second), a number of very short light pulses will be deflected towards the light detector 73 . Each and every one of these light pulses has its own specififc time interval within the entire scanning cycle.
• the binary searching method described above can also be applied to image screens by appropriate.programming of the process equipment. In the case of a cathode ray tube, however, the beam scans across the screen at very high speed, for which reason the use of binary searching appears not to be quite so convenient.
• control field' is used to denote not only permanently marked, visible fields on the command .console, but also fields such as keys which are capable of mechanical operation, and also yields which consist only of illuminated parts of the surface of the control panel without having any permanent, material marking.

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• 1984
  • 1984-03-12 SE SE8401351A patent/SE440969B/sv not_active IP Right Cessation
• 1985
  • 1985-03-11 EP EP19850901622 patent/EP0208690A1/de not_active Withdrawn
  • 1985-03-11 JP JP85501231A patent/JPS61501422A/ja active Pending
  • 1985-03-11 WO PCT/SE1985/000107 patent/WO1985004295A1/en not_active Application Discontinuation
  • 1985-11-08 DK DK516785A patent/DK516785A/da not_active Application Discontinuation
  • 1985-11-11 NO NO854479A patent/NO854479L/no unknown

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