1. Field of the Invention
This invention relates in general to garage door operators and in particular to a novel garage door operator wherein the receiver can be energized by two or more transmitted codes which are stored in the receiver.
2. Description of the Prior Art
Garage door operators of the prior art used transmitters in which the code can be changed by various methods as, for example, by moving two position switches to change the code. Such systems have also used code changing switches in the receiver so that the receivers can be set to correspond to the selected transmitter code.
It has also been known to use fixed frequency transmitters and fixed frequency receivers such that if the transmitted frequency matches the receiver frequency the receiver will respond.
It is an object of the present invention to provide a plurality of transmitters wherein each transmitter has its own unique and permanent non-user changeable code and wherein the receiver can be placed into a program mode wherein it will receive and store two or more codes corresponding to two different transmitters. The number of codes which can be stored in transmitters can be extremely high as, for example, greater than one million codes. Thus, the invention makes it possible to eliminate the requirements for code selection switches in the transmitters.
In the present invention the decoder module in the receiver will be capable of learning several different transmitted codes which will eliminate code switches in the receiver and also provides for multiple transmitters for actuating the garage opener.
The communication link can be various system such as radio frequency, light, wires, etc.
The invention makes it very easy for the user to operate the system and more secured code systems are available due to the higher number of available codes.
An encoded signal will be utilized wherein a pulse and blank time comprises a sync time base and different link pulses such as 1, 2, 3 or 4 milliseconds can be selected so as to provide different codings. Each datum can be 1, 2, 3 or 4 times the length of the sync pulse. The timing is from the rising edge to rising edges of the pulse and with ten data bits the number of codes can be in excess of one million codes.
In the invention, each transmitter encoder will contain a chip which contains a unique code and the receives will be able to memorize two or more as, for example, five different transmitter codes. This eliminates the need to have coding switches in either the transmitter or receiver. This eliminates the requirement that the user set the code switches so they match since the code switches are eliminated.
In the invention, during an operate mode, a receiver code must match an already programmed code four times in order to operate the garage door. This match is referred to as a valid code. Each valid code can be separated by up to two error codes and still have the output indicated as accurate.
In the program mode a code must be received four times in a row in order to be permanently stored in the receiver. Any error code will reset the valid code counter.
The advantage of the coding scheme are:
1. Higher peak power without exceeding the FCC rules which gives longer transmitter range.
2. Eliminate code switches in the transmitter and receiver making it easier for a customer to install and operate his garage door operator.
3. Customers having more than one transmitter will not have to match codes.
4. More secure codes due to the higher number of combinations which are available. Other objects, features and advantages of the invention will be readily apparent from the following description of certain preferred embodiments thereof, taken in conjunction with the accompanying drawings although variations and modifications may be effected without departing from the spirit and scope of the novel concepts of the disclosure and in which: