US3648279A - Multielectrode transducer element - Google Patents

Multielectrode transducer element Download PDF

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Publication number
US3648279A
US3648279A US37124A US3648279DA US3648279A US 3648279 A US3648279 A US 3648279A US 37124 A US37124 A US 37124A US 3648279D A US3648279D A US 3648279DA US 3648279 A US3648279 A US 3648279A
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United States
Prior art keywords
electrodes
elements
mechanically
electrode
combination
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Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
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US37124A
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English (en)
Inventor
James Power Watson
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RCA Corp
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RCA Corp
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Publication date
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Publication of US3648279A publication Critical patent/US3648279A/en
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
    • B41J5/00—Devices or arrangements for controlling character selection
    • B41J5/08—Character or syllable selected by means of keys or keyboards of the typewriter type
    • 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
    • H03K17/964—Piezoelectric touch switches
    • H03K17/9643—Piezoelectric 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
    • H03K17/965—Switches controlled by moving an element forming part of the switch
    • H03K17/967—Switches controlled by moving an element forming part of the switch having a plurality of control members, e.g. keyboard
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10N30/00—Piezoelectric or electrostrictive devices
    • H10N30/30—Piezoelectric or electrostrictive devices with mechanical input and electrical output, e.g. functioning as generators or sensors
    • H10N30/302—Sensors

Definitions

  • ABSTRACT A transducer means suitable for use as the mechanical-toelectrical translating element of the key of a keyboard. It includes a plurality of electrodes embedded in a body of amorphous, piezoelectric material. When the key is actuated to strike the body, a voltage is induced at each electrode.
  • the electrodes of the various keys may be connected in different ways to common buses to provide a coded output from the keyboard.
  • Crystals which have the proper axis of out are suitable for keyboard transducers, but, because of their delicate nature, are subject to catastrophic failure if overstressed. This in tum requires careful initial alignment of the keyboard assembly, to prevent overstressing and this too increases the expense of the keyboard.
  • crystals generally produce multiple signals (a ringing oscillation) in response to a single mechanical stimulus.
  • circuits such as gate circuits, are needed to suppress, say, all oscillations following the first one.
  • An object of this invention is to provide new and improved piezoelectric devices which are sturdy, relatively inexpensive, and are capable of translating a mechanical stimulus to a relatively large group of concurrent signals.
  • Another object of this invention is to provide a'new and improved keyboard employing piezoelectric transducers.
  • An element of the type which in response to being mechanically struck induces a voltage change in an electrode mechanically coupled therein.
  • a plurality of such electrodes are mechanically coupled in the element, and means are included for striking the element for concurrently producing a plurality of signals, one at each electrode.
  • a keyboard according to the invention includes a plurality of such elements interconnected in different ways to a common output bus and each responsive to a different key.
  • FIG. I is a side view, partially in section, of a keyboard element embodying the invention.
  • FIG. 2 is a top view of the keyboard element illustrated in FIG. 1;
  • FIG. 3a is a side view of another keyboard element configuration embodying the invention.
  • FIG. 3b is a top view of the keyboard element of FIG. 3a;
  • FIG. 4a is a top view of yet another keyboard element configuration embodying the invention.
  • FIG. 4b is a section of the keyboard element of FIG. 4a taken along the lines 4b;
  • FIG. 5 is a diagram of a standard keyboard which may be used in the practice of the invention.
  • FIG. 6 is a schematic diagram illustrating howthe Baudot Code may be obtained from a keyboard formed from the keyboard elements illustrated in FIG. 1.
  • FIG. 1 illustrates a device 2 which is useful, for example, as a keyboard element.
  • the body 4 of the device is formed of an amorphous material which exhibits piezoelectric characteristics. Some typical materials which are especially suitable include plastics such as polytetrafluoroethylene.
  • Flange 6 is mechanically pressed into the body 4 and in turn is secured in a baseplate member 8.
  • a plurality of conducting electrodes 10, which, for example, may be formed of copper or any other good conductor of electricity, are embedded in the body 4.
  • the electrodes 10 may be secured in place in apertures in the body 4 by threads, flanges, or knurling, etc. Alternatively, the electrodes may be mechanically coupled to the body 4 in other ways well known in the art.
  • Supporting members 12 and l4 are attached to baseplate member 8, for example, by screws (not shown), and also to a member 16.
  • a flat spring 18 of a key 20 is secured to point 22 of member 16 by means of screws (not shown) or spot welding.
  • Flat spring 18 is also secured to a striking or impacting means 24 and to one end of a coil spring 26 which form part of the key 20. The other end of the spring 26 is attached to the key top 28.
  • a latch 30 is pivotally mounted to member 16 by means of a pin 32. Latch 30 is biased into the position shown by means of a spring 34.
  • a retaining element 36 is attached to member 16 to prevent latch 30 from traveling any further than the element 36.
  • latch 30 When the force applied to the key top is removed, latch 30 returns to its rest position due to the tension of spring 34.
  • the upward bias of spring 18 returns striking element 24 to its rest position.
  • latch 30 In the event latch 30 returns prior to the return of spring 18, the end 38 of the spring 18 slides over the angled surface 41 of the latch to the rest position.
  • electrodes 10 are embedded to equal depths, voltages of essentially equal magnitude are induced in each of the electrodes I0.
  • the signal is taken from the interior of element 4, rather than externally as is done with a piezoelectric crystal.
  • FIG. 2 is a top view of the element 4 in which seven electrodes 10 are embedded. A greater or lesser number of electrodes may be utilized depending on the needs of the particular user. Since the element 4 is formed of a plastic, it is very durable and can withstand great stress. This results in a long operational life and minimal failure.
  • a keyboard unit employing a plurality of elements such as shown in FIGS. 1 and 2 is rugged and relatively insensitive to vibration.
  • the design chosen for the key is but one of many that may be used in the practice of the invention. Even if a design is chosen in which the impacting or striking means applies forces of varying magnitude to the body 4, for different forces applied to the keytop, the magnitude of the induced voltages in the electrodes 10 does not vary to an extent sufiicient to degrade operation.
  • the body 4 and electrodes 10 may be fabricated in ways other than shown in FIGS. 1 and 2,
  • FIGS. 30 and 3b in which a plurality of bodies 4 are embedded in a baseplate member 42.
  • FIG. 3a is a side view of the bodies and
  • FIG. 3b is a view looking downward on the impact surfaces of the bodies.
  • the electrodes 10 run substantially parallel to the impact surface of the body 4 whereas in FIGS. 1 and 2 the electrodes ran substantially perpendicular to the impact surface.
  • the electrode 100 is situated nearer the impact surface of the bodies 4 than are the electrodes 10d, We, and 10f. If the electrodes are of the same size, a voltage of a greater magnitude is induced in electrode 100 than in 10d when body 40 is impacted. If it is desired that the voltage induced in each electrode, in this arrangement, be the same, the surface area of the electrodes l0d-f could be made greater than the surface area of the electrode 10c. A greater or lesser number of electrodes may be passed through the bodies 4, depending upon the needs of the particular user.
  • FIG. 4 illustrates yet another way in which the bodies and electrodes may be fabricated in a laminated form.
  • a baseplate member 44 (FIG. 4b) has a first sheet of plastic 46, of the type used for the bodies 4 earlier described, secured to its surface by means of cementing, bonding, etc.
  • a plurality of conductors 48 which may be flat or of circular cross section, is then placed on top of the sheet 46.
  • a second sheet of plastic 49 is placed over the conductors 48 and secured to sheet 46.
  • a plurality of conductors 50 is placed on top of sheet 49 substantially perpendicular to the direction at which the conductors 48 were placed.
  • a third sheet of plastic 52 is placed over the conductors 50 and secured to the sheet 49.
  • FIG. 4a illustrates the laminated structure looking downward on the impact surface of the structure.
  • the dotted circles 54, 56, 58 and 60 define the areas at which the striking or impacting means of a key would strike the structure. For example, if the area defined by circle 54 were impacted, a voltage would be induced in conductors 48a and 50a. It is to be understood that a greater or lesser number of conductors and sheets of plastic may be utilized in the practice of the invention.
  • FIG. 6 illustrates how certain electrodes of each keyboard element are connected to a plurality of output terminals for generating a different code for each key which is depressed.
  • a five-bit code such as a Baudot Code is employed so that each element has five electrodes.
  • any other code using a different number of bits may be employed in which case there would be a greater (or fewer) number of electrodes per element, as needed.
  • the five circles 10a directly under the letter A represent the electrodes which are mechanically coupled to the body 4 for the A key.
  • the remaining keys are illustrated in similar fashion.
  • an electrode represented by a clear circle (and that does not have a line connected to an output terminal) represents a binary 0 in the code
  • an electrode represented by a black circle (and connected by a line to an output terminal) represents a binary l in the code, when the key is depressed.
  • key A has the 2 and 2 output terminals representing a l and the 2 -2 representing a 0 when key A is depressed.
  • the codes for the remaining keys are easily determined by referring to the remaining electrode connections.
  • the output terminals 2-2 may be connected to any sensing device or computer which acts upon the information generated by the keyboard. Since the information comes from the keyboard in coded form, there is no encoding or gating device needed between the keyboard and the computer.
  • a keyboard comprising, in combination:
  • decoder means coupled to said electrodes and responsive to i the voltages induced therein, for producing a unique signal code for each element.
  • a keyboard comprising in combination:

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  • Input From Keyboards Or The Like (AREA)
  • Push-Button Switches (AREA)
US37124A 1970-05-14 1970-05-14 Multielectrode transducer element Expired - Lifetime US3648279A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US3712470A 1970-05-14 1970-05-14

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US3648279A true US3648279A (en) 1972-03-07

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US37124A Expired - Lifetime US3648279A (en) 1970-05-14 1970-05-14 Multielectrode transducer element

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US (1) US3648279A (enrdf_load_stackoverflow)
JP (1) JPS466821A (enrdf_load_stackoverflow)
CA (1) CA936104A (enrdf_load_stackoverflow)
CH (1) CH538155A (enrdf_load_stackoverflow)
DE (1) DE2123822A1 (enrdf_load_stackoverflow)
FR (1) FR2091584A5 (enrdf_load_stackoverflow)
GB (1) GB1345895A (enrdf_load_stackoverflow)
NL (1) NL7106589A (enrdf_load_stackoverflow)
SE (1) SE367496B (enrdf_load_stackoverflow)

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3749947A (en) * 1971-08-28 1973-07-31 Denki Onkyo Co Ltd Switch devices
US3792467A (en) * 1973-01-08 1974-02-12 Control Data Corp Impact transducer apparatus
US3903436A (en) * 1973-02-23 1975-09-02 Mansei Kogyo Kk Piezoelectric generating device
US3935485A (en) * 1973-09-17 1976-01-27 Kureha Kagaku Kogyo Kabushiki Kaisha Piezoelectric key board switch
US3940637A (en) * 1973-10-15 1976-02-24 Toray Industries, Inc. Polymeric piezoelectric key actuated device
US4071785A (en) * 1975-05-02 1978-01-31 Kureha Kagaku Kogyo Kabushiki Kaisha Laminated piezoelectric matrix switch
US4234813A (en) * 1978-04-10 1980-11-18 Toray Industries, Inc. Piezoelectric or pyroelectric polymer input element for use as a transducer in keyboards
US4580074A (en) * 1984-11-26 1986-04-01 General Motors Corporation Piezoelectric transducer with coded output signal
US4975616A (en) * 1988-08-18 1990-12-04 Atochem North America, Inc. Piezoelectric transducer array
US5636729A (en) * 1995-06-12 1997-06-10 Wiciel; Richard Piezo switch
US20130188341A1 (en) * 2012-01-16 2013-07-25 Shen-Ko Tseng Power generating device
US20230036761A1 (en) * 2021-07-30 2023-02-02 Neptune Technology Group Inc. Method and system for transducer validation

Families Citing this family (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5130911Y1 (enrdf_load_stackoverflow) * 1970-12-17 1976-08-03
JPS51138327A (en) * 1975-05-26 1976-11-29 Nippon Telegr & Teleph Corp <Ntt> Piezoelectric film switch
JPS5257982A (en) * 1975-11-08 1977-05-12 Nippon Telegraph & Telephone Piezooelectric keyboard
JPS52135287A (en) * 1976-05-28 1977-11-12 Kureha Chemical Ind Co Ltd Method of inputting piezooelectric signal
JPS5372182A (en) * 1976-12-09 1978-06-27 Kkf Corp Electrical signal generator
DE2718289A1 (de) * 1977-04-25 1978-10-26 Rosenthal Technik Ag Piezokeramischer schalter mit geringer einbautiefe
JPS5747435A (en) * 1980-09-01 1982-03-18 Fuji Oil Co Ltd Base material for making cheese cakes

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US23813A (en) * 1859-04-26 Leonard b
US2824980A (en) * 1952-03-14 1958-02-25 Erie Resistor Corp Piezoelectric transducers
US2864013A (en) * 1953-06-29 1958-12-09 Electro Voice Sensitive strain responsive transducer and method of construction
US3366808A (en) * 1966-01-03 1968-01-30 Friden Inc Keyboard key transducer
US3464531A (en) * 1967-05-16 1969-09-02 Us Army Manual electronic keyboard

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US23813A (en) * 1859-04-26 Leonard b
US2824980A (en) * 1952-03-14 1958-02-25 Erie Resistor Corp Piezoelectric transducers
US2864013A (en) * 1953-06-29 1958-12-09 Electro Voice Sensitive strain responsive transducer and method of construction
US3366808A (en) * 1966-01-03 1968-01-30 Friden Inc Keyboard key transducer
US3464531A (en) * 1967-05-16 1969-09-02 Us Army Manual electronic keyboard

Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3749947A (en) * 1971-08-28 1973-07-31 Denki Onkyo Co Ltd Switch devices
US3792467A (en) * 1973-01-08 1974-02-12 Control Data Corp Impact transducer apparatus
US3903436A (en) * 1973-02-23 1975-09-02 Mansei Kogyo Kk Piezoelectric generating device
US3935485A (en) * 1973-09-17 1976-01-27 Kureha Kagaku Kogyo Kabushiki Kaisha Piezoelectric key board switch
US3940637A (en) * 1973-10-15 1976-02-24 Toray Industries, Inc. Polymeric piezoelectric key actuated device
US4071785A (en) * 1975-05-02 1978-01-31 Kureha Kagaku Kogyo Kabushiki Kaisha Laminated piezoelectric matrix switch
US4234813A (en) * 1978-04-10 1980-11-18 Toray Industries, Inc. Piezoelectric or pyroelectric polymer input element for use as a transducer in keyboards
US4580074A (en) * 1984-11-26 1986-04-01 General Motors Corporation Piezoelectric transducer with coded output signal
US4975616A (en) * 1988-08-18 1990-12-04 Atochem North America, Inc. Piezoelectric transducer array
US5636729A (en) * 1995-06-12 1997-06-10 Wiciel; Richard Piezo switch
US20130188341A1 (en) * 2012-01-16 2013-07-25 Shen-Ko Tseng Power generating device
US9143060B2 (en) * 2012-01-16 2015-09-22 Shen-Ko Tseng Power generating device
US20230036761A1 (en) * 2021-07-30 2023-02-02 Neptune Technology Group Inc. Method and system for transducer validation

Also Published As

Publication number Publication date
DE2123822A1 (de) 1971-12-02
NL7106589A (enrdf_load_stackoverflow) 1971-11-16
CH538155A (de) 1973-06-15
SE367496B (enrdf_load_stackoverflow) 1974-05-27
GB1345895A (en) 1974-02-06
FR2091584A5 (enrdf_load_stackoverflow) 1972-01-14
CA936104A (en) 1973-10-30
JPS466821A (enrdf_load_stackoverflow) 1971-12-15

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