Electrical transmission or interconnection systems – Nonlinear reactor systems – Parametrons
Patent
1987-06-26
1989-10-31
Hille, Rolf
Electrical transmission or interconnection systems
Nonlinear reactor systems
Parametrons
357 17, 307116, 361174, 340706, 250221, 220 21R, 341 31, H01L 2328
Patent
active
048781070
DESCRIPTION:
BRIEF SUMMARY
INTRODUCTION
This invention relates to a touch sensitive indicating light and more particularly relates to a light emitting diode that incorporates a touch or proximity sensor that operates as switching means.
BACKGROUND OF THE INVENTION
Light emitting diodes known as LEDs have become very popular in the electrical/electronic industries. A light emitting diode is a solid state electronic component typically comprising a forward biased p-n semi-conductor junction diode. Light is emitted very close to, or within the junction region as injected holes and electrons diffuse across the junction and combine. The combining holes and electrons release energy and some of this energy is released directly as photons. Light emitting diodes can be fabricated by diffusing p and n type impurities into a suitable semi-conductor to form a junction. A semi-conductor commonly used to fabricate light emitting diodes which emit light in the visible spectrum, is gallium arsenide phosphide.
The diode is conventionally encapsulated in plastics and defines a cylindrical construction with a domed top, the diameter of the assembly being in the order of 5 mm.
Light emitting diodes perform a significant role in the electrical/electronic industry. They provide a simple and effective means of indicating a particular state of a variety of components in an electronic circuit. Their small size and durability makes them ideal for use on instrument panels and on circuit boards. They are frequently used to indicate the state of switching means and are often positioned adjacent to a switch to indicate the state of the switch.
In recent times companies such as Hewlett Packard have produced LEDs that incorporate integrated circuits within the structure of the LED.
SUMMARY OF THE INVENTION
The present invention provides a light emitting diode that has built in switching capacity.
The present invention also provides a touch sensitive light emitting diode comprising a diode encapsulated in a plastics dome and externally operable touch sensitive switching means positioned within the plastics dome, the switching means including an output to external electronics and the diode providing visual indication of the state of the switching means.
Preferably the switching means comprises a conductive region positioned on or adjacent the top of the plastic dome.
The switching means may be a resistive touch switch, a voltage detection touch switch, a capacitance detection touch switch, or a proximity detection touch switch.
In one embodiment the switching means comprises a stress/strain sensitive element positioned within the plastics dome whereby external pressure on the top of the dome is sensed by the stress/strain sensitive element.
The stress/strain sensitive element may comprise a resistor, a piezoelectric or piezoresistive layer, or a semi-conductor piezoresistor or a transistor.
In one other embodiment the switching means comprises a light sensitive element which detects light from the light emitting diode reflected from an object or finger tip in proximity to the top of the plastics dome. The light sensor may comprise a phototransistor or a photodiode.
The term "dome" as used in this specification relates to the top portion of the diode which could prevent a variety of profiles to the exterior.
DESCRIPTION OF THE DRAWINGS
Various embodiments of the present invention will now be described by way of example only with reference to the accompanying drawings, in which:
FIGS. 1 to 7 are side elevational views illustrating various examples of light emitting diodes that incorporate switching means;
FIG. 8 is a block circuit diagram illustrating one example of the use of an LED incorporating switching means;
FIG. 9 is a circuit diagram illustrating the LED of FIG. 8 used to control a toggling output;
FIG. 10 is a circuit diagram illustrating the use of an LED with switching means to provide a switch with a simple "momentarily on" output;
FIGS. 11a, b and c are respectively plan, side and front elevations views of an LED incorporating a stress/strain se
REFERENCES:
patent: 3372789 (1968-03-01), Thiele et al.
patent: 3805347 (1974-04-01), Collins et al.
patent: 3855606 (1974-12-01), Schoberl
patent: 3922563 (1975-11-01), Penman
patent: 3944843 (1976-03-01), Vaz Martins
patent: 4032963 (1977-06-01), Thome
patent: 4047075 (1977-09-01), Schoberl
patent: 4152629 (1979-05-01), Raupp
patent: 4514276 (1985-04-01), Covington et al.
patent: 4550310 (1985-10-01), Yamaguchi et al.
patent: 4591710 (1986-05-01), Komadina et al.
patent: 4629884 (1986-12-01), Bergstrom
patent: 4668876 (1987-05-01), Skarman
patent: 4737626 (1988-04-01), Hasagawa
patent: 4761637 (1988-08-01), Lugas et al.
Ludeman, "Miniature Optical Keyboard", IBM Technical Disclosure Bulletin, vol. 15, No. 11, Apr. 1973, pp. 3348-3349.
Hille Rolf
Loke Steven Ho Yin
LandOfFree
Touch sensitive indicating light does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Touch sensitive indicating light, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Touch sensitive indicating light will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-629211