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
  • H03K17/965—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

Definitions

• This patent relates to an optical keyboard characterized in that it comprises in particular keys taken into account by specific light means so that their ' simultaneous pressing with other keys can be identified without error.
• the term "light” will be used here to designate not only the visible spectrum but also the radiant energy emitted in the non-visible spectrum. This light can be ambient light, light from infrared diodes, lasers, or any other light source.
• the term "main light path” will designate, unless otherwise specified, all the means making it possible to conduct light through the keyboard from a source to a detector: focusing of a beam in any medium, empty optical channel whose walls can be reflective, duct formed of a transparent material.
• "Optical fiber” is considered here as a particular category of optical conduits. The light path can take deviations in various successive directions using optical paths or. has reflecting devices such as mirrors, polished or chromed metals, prisms or any other device of this kind. These particular directions separating the main light ray into several secondary rays will be called “individual optical paths”.
• By “combination key” we mean the keys which can be pressed simultaneously with other keys without interfering with the precise identification of any of them.
• - Modularity the same light source, the same photodetector, which can participate in the identification of several different keys, the use of this technology allows the production of modular supports likely to be configured to meet specific requirements depending on customers.
• - Ergonomics optical technology makes it much easier to adopt keyboard settings accessible to the user, in particular concerning the stroke of the keys and their sensitivity;
• - Ecology traditional keyboards generally emit radio waves and the action of their contacts can generate sparks; the absence of this pollution deserves to be exploited in certain specific applications; thanks to optical links with electronic centers, it is possible to eliminate all electronics in the immediate vicinity of the keyboard.
• An object of the present invention is the production of an optical keyboard for an office machine, a machine tool or a musical synthesizer for example; can detect several keys pressed simultaneously. This need is obvious for musical synthesizers.
• Another object of the present invention is the production of an optical keyboard which comprises a support capable of receiving key configurations adopting various layout topologies.
• the preferred embodiments of the present invention describe different embodiments of a keyboard, economical optics allowing the detection of several keys pressed simultaneously, while developing the modularity, ergonomics and ecology of such a keyboard.
• the description below does not concern the electronic card and the software for processing the electrical signals sent to it by the keyboard.
• This part * of the keyboard is well known. It is known in particular to give the signals coming from the photodetectors a frank and precise character in particular by using hystereses or optical codes in series.
• the present invention relates to an optical keyboard comprising: a plurality of light sources, each source being arranged to send light in a given path traversing the keyboard; a plurality of photodetectors, each photodetector being arranged to receive light from a light path traversing the keyboard; and a plurality of keys each having a coupling position in which an optical coupling is ensured between at least one of said light sources and at least one of said photodetectors, and a non-coupling position in which said coupling is not insured; at least some of said sources and said photodetectors being arranged to each participate in the identification of several keys.
• the optical keyboard of the present invention is characterized in that at least some of these keys are keys that n 1 combinantes action upon the optical paths of input and output of light to them clean and exclusive, the position of these combination keys being detected reliably regardless of the position of the other keys, combination or not, of the keyboard.
• FIG. 1 shows an exploded and perspective view of an embodiment of a first optical keyboard
• FIG. 2 shows a partial perspective view of an embodiment of a second optical keyboard
• FIG. 3 shows a partial perspective view and partially exploded of an embodiment of a third optical keyboard
• FIG. 4 shows a side view of an embodiment of a fourth optical keyboard
• FIG. 5 shows schematically a partial view of an embodiment of a fifth optical keyboard
• FIG. 6 is a schematic view of an embodiment of a sixth optical keyboard
• - Figure 7 is a side view of a detail of a variant of the keyboard of Figure 6;
• FIG. 8 is a schematic view of an embodiment of a seventh optical keyboard
• Figure 9 is a logic diagram applicable to the keyboard of Figure 8.
• FIGS. 10 and 11 are respectively a vertical section and a horizontal section through a first variant key for the keyboard of Figure 8;
• FIG. 12 is a vertical section of a second variant of the key for the keyboard of FIG. 8.
• the keyboard is formed by a rectangular hollow support 10. Keys 13 are arranged to penetrate more or less deeply into the hollow zone of this support where light beams intended to identify circulate. the keys pressed.
• two arrays 11 of light sources are fixed on two side walls of the support 10, and two strips 12 of photodetectors are fixed on the two sides facing the walls carrying the sources.
• the interval separating the optical components can be equal to the size of the cap of a key (13) except for certain keys which are combination keys (capital keys, for example) which have one or more specific row beams (14) or column, which may possibly be located on a plane higher than the other beams so that the depression of such a combination key does not disturb the other signals.
• the bottom of the support can be lined with an elastic cushion intended to absorb the impact of the keys at the end of the stroke.
• the light sources are preferably supplied by pulses so as to extend their lifespan and to increase the point power of the beams which they deliver. They are successively lit in an order such that no photodetector 15. cannot confuse the light of its row or column with that of a neighboring source when a key is pressed. The risks of mutual interference are also reduced if the bars 11, 12 are replaced by mixed bars (not shown), each having a series of optical components alternating the light sources with the detectors. Alternatively, it is possible to provide , either a grid of walls insulating each of the channels / or from the outset an installation of conduits or optical channels in the support as shown in FIGS. 2 and 3.
• the stem of the keys can end in the form of a golf cane 16 which comes to interrupt, when pressed, a column light path and a row light path even if these are off the axis of the stem.
• optical conduits FIG. 2
• the shank of the fingerboard is equipped with a thin blade or two thin opaque blades profiled in T 17 which, to interrupt the light when the key is pressed, requires in the conduits only a thin cut 18 not causing excessive light leakage.
• optical channels FIG.
• the light source and the photodetector will be on the same side of the row and of the column, in which case the key rod will be equipped with a reflecting device returning the light to the corresponding photodetector when the key is pressed.
• an optical detection support 20 provides a series of parallel light paths formed by conduits, by channels 21, or resulting from a scanning without materialization of conduits, in row or in column .
• Each combination key is assigned an individual light path 22 among the paths of a series. This individual path is specific in that no other key apart from the combination key can close it, and, conversely, the combination key does not act on any of the paths intended for the identification of the other keys.
• an individual optical path 27 can also be used to generate a "ready" signal indicating that a key is actually pressed and that the combination of the free and closed paths has a parallel code correctly identifying the key pressed. As shown in FIG.
• this organization of the light paths offers great flexibility in determining the location of the keys.
• a hole can be made to implant the stem of a key.
• the latter 24 is pierced with orifices 23 in order to allow the light to circulate in the rest position.
• the closing of certain orifices 23 forms a code specific to the key, thus enabling the photodetectors to identify it. It appears desirable to provide an upward offset of one of these closed orifices 27 so as to create the "ready" signal described above.
• Reflective devices can also be substituted for the closed orifices in order to organize a detection by reflection.
• the flexibility of setting up the keys can be further increased by arranging additional light paths 26 between two rows making it possible to have several intermediate rows.
• FIG. 4 defines a detection in parallel.
• a serial code bar code for example
• parallel codes organize the detection of serial codes on the same row.
• the keys emit a serial identification code on a single optical row.
• This keyboard can be built by transposing the mechanical principles of old typewriters.
• the keys 31 mounted on a lever 32 s * hinging around a central axis 38 are held in the rest position by means of a counterweight 33 or a spring bringing them back to a stop 34.
• a device identification optic 35 which crosses one or more light paths 36 and causes the emission of an identification code by interruption or by reflection which is detected by one or more photodetectors.
• One or more light paths individual 37 can also be arranged to allow the establishment of so-called "combining" keys.
• the identification device 35 can be in the form of a window marked with a bar code identifying the corresponding key. When crossing a light path, this code is emitted as a series of pulses detectable by conventional means as is commonly seen at supermarket checkouts.
• This identification device could also be of the parallel type (FIG. 4) or of the analog type (variety of colors or gray for example).
• the embodiments described so far only allow restricted combinations either of keys which can be combined with any other key on the keyboard, or (in the case of FIG. 5 for example) because the keyboard allows a certain degree " of key combination in that, once it is fully depressed, a key no longer interferes with the detection of the passage of other keys from the rest position to the depressed position.
• a matrix system makes it possible to identify any combination of keys pressed simultaneously.
• a key is pressed reflecting means 43, only partially obstructing the circulation of light in the columns and in the rows, located at its base return the light collected on a column 41 to the photodetector of a row 42.
• the columns are identified by their time position in a scanning sequence of the light sources, the rows are identified by their own photodetectors, and each key is identified by its column and row coordinates.
• each light path (column and rows or row and columns) encloses, in fact, several separate individual optical paths therefore each is exclusively specific to the key which crosses the path.
• the mirrors in the lower row will be able to return the light to photodetectors located on the right of the optical support and the mirrors in the next row 44 will return it to the left and so on.
• the upper mirrors will be able to recover part of the remaining light.
• the mirrors 45 of the highest row can be given a larger dimension. It is also possible to play, as for the rows, on the angle of the optical column paths.
• distributor conduits 46 Such a conduit has a main facet 47 facing an optoelectronic component 48 and several facets secondary 49 facing the reflecting means specific to each key.
• the conduit .distributor 46 has a shape such that the light passing through the main facet 47 and is adequately distributed between the secondary facets 49.
• said optoelectronic component can be either a light source or a photodetector.
• Each distributor conduit comprises a set of optical conduits. All are joined by one of their ends facing an optoelectronic component, the other end of each of these conduits facing a button which is specific to it.
• the light path of each optical component therefore comprises all of the conduits with which the component is coupled, while each of these conduits constitutes an individual optical path specific to a particular key.
• the resulting optical paths associate each light source 51 with several photodetectors 52 by forming several independent paths each of which is specific to a key 53.
• the light sources are subjected to periodic scanning and are identified by the time of their ignition in the sweep period. With three light sources and three photodetectors can identify up to nine different keys.
• the button 2B has an individual optical path 59 which is specific to it. In the example in FIG. 8, pressing the button 2B interrupts or lets light pass through this individual optical path.
• the key is identified by photodetector B and * when the light source 2 is switched on.
• each key 53 has at least two positions in one of which the light is coupled between its optical path of arrival 54 towards its optical path of departure 55, and in the other of which the light is not coupled. It is also possible to construct keyboards with three key positions, for example two extreme positions (rest, pressed) which are identical and an intermediate position (of short duration) between said extreme positions.
• the optical keyboards also facilitate the measurement of the key press speed either through the light variation, or by positioning the light paths on two different levels, or by constructing the rods of the keys so that they emit several signals on the optical paths during a sinking cycle, in order to enrich the messages transmitted by the user. This applies to all the embodiments described by this patent.
• the reflecting device can be the user's finger, in which case the key is only a place intended to receive it.
• the reflecting device can be a reflecting surface actuated by a mechanical device. The reflection is carried out near the button of the optical path of arrival to the optical path of departure.
• These two conduits can be joined into a third conduit by an optical connector on the market.
• the key leaving the rest position sends a first signal, then the mask ⁇ 8 interrupts this signal which reappears again when pressed.
• the time separating these two signals can be measured by the electronic system which can deduce the speed at which the key is pressed and the strike force of the user.
• the third signal emitted by the key which returns to the rest position can be used for verification functions.
• FIG. 12 shows a key 53 having a shutter 56 which in the depressed position interrupts the coupling between the optical paths 54 and 55.
• the device cutting the light can be designed in various ways.
• the example shown in Figure 12 is that of a very thin opaque screen. It is also possible to provide a blade pierced with one or more holes the size of the optical conduit whose reflective edges participate in the conduction of light.
• the individual optical paths are normally materialized in the form of flexible conduits, possibly sheathed (FIG 8), optical fibers for example. Having an appropriate length, they can be connected to keys fixed on a separate plate in an arrangement which can vary according to the needs of the customers.
• the conduits can also be embedded in a support, preferably optically insulating, which is then drilled and cut to receive the keys, their rods and their springs.
• the contact or reflection mechanisms can be enclosed in a sealed assembly using an elastic membrane or magnetic devices.

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• 1985
  • 1985-09-09 EP EP19850904263 patent/EP0193556A1/de not_active Withdrawn
  • 1985-09-09 WO PCT/FR1985/000239 patent/WO1986001954A1/fr unknown

Non-Patent Citations (1)

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