mslater@cup.portal.com (Michael Z Slater) (05/18/91)
I believe the Hayes patent is a great example of the failure of our patent system. It protects something that, in my view, isn't an invention and does not deserve protection. Futhermore, its protection has not been critical to Hayes' success, and the industry benefits by standardization on the Hayes sequence. The following is an editorial I wrote on the Hayes patent situation. I think it adds relevant information to this discussion, so I'm posting it in its entirety rather than trying to summarize it. Copyright 1991, MicroDesign Resources Inc. Originally published in the 20 Mar 91 issue of the Microprocessor Report. Permission to copy is granted provided that this notice and the signature at the end are included. ------------- Hayes Abuses Patent to Suppress Competition Circuit-Design Patent Manipulated to Cover Protocol Standard Hayes Microcomputer Products recently won a patent infringement suit against a group of modem manufacturers, including Everex Systems, Omnitel, and Ven-Tel, that could force these companies to pay Hayes millions of dollars in licensing fees. Before going to trial, U.S. Robotics and Prometheus Products settled with Hayes. The nature of the "invention" and the history of the patent make this case one of the most egregious examples of patent system abuse, and the decision may yet be overturned on appeal. The coverage in the trade press failed to illuminate any of the key issues, which deserve to be more widely understood. The case centers around patent 4,549,302, filed October 11, 1983 and granted October 22, 1985. The inventor is Dale Heatherington, and the patent is assigned to his employer, Hayes Microcomputer Products. This patent is actually a continuation of an application originally filed in June 1981. The patent covers the circuit design of the Hayes Smartmodem 300. This was one of the first reliable modems to be widely distributed in the personal computer market, and quickly acquired "standard" status. The patent describes how the cost of the modem is reduced by using certain circuit elements to perform different functions at different times, under the control of a microprocessor. For example, the FSK demodulator is also used to detect a ringing signal when the phone is on-hook, and the FSK modulator is used to produce part of the DTMF signals for dialing. The patent describes the operation of this circuitry in great detail, consuming six pages of figures and eight pages of text. The original patent application was titled "Modem With Low Part Count and Improved Demodulator." The '302 patent resulted from a division of that application. When the division was filed in late 1983, the title was changed to "Modem With Improved Escape Sequence to Prevent Escape in Response to Random Occurrence of Escape Character in Transmitted Data." Half of the abstract is devoted to describing this feature: "When the modem is in a transparent mode of operation, for transmitting data, a timer detects the passage of a predetermined period of time after the most recent data input signal to a data port. If the next sequence of data signals corresponds to an escape character, the program controlling the modem waits to see if a second occurrence of the predetermined period of time follows provision of the escape character. If this occurs, the modem switches to a command mode of operation in which it ceases to modulate and transmit signals and waits for commands to be entered at the data port." This "guard time" method, which eliminates the possibility that an escape sequence can occur accidentally within a continuous data stream, is the sole basis for the infringement claims. None of the original patent application claims were directed to this technique; they were devoted entirely to the circuit design. Other modem manufacturers used different circuit designs, so no infringement of the original patent claims occurred. But because the Hayes modem was the most widely used, authors of communications software used the escape sequence as required by the Hayes modem. Other modem vendors then used the same escape sequence for compatibility with this software. The inspiration to add the escape sequence method to the patent seems to have come from another patent that Hayes paid to license. In 1983, Dr. Eaton of Bizcomp was granted a patent on a simple escape sequence, and in September of that year, Hayes paid $2 million to license that patent. (This patent was later invalidated on grounds of obviousness.) The next month Hayes filed the revised patent application, changing the title and adding a few sentences covering the escape sequence with guard time. While half of the new abstract is devoted to this technique, it is barely mentioned in the body of the patent which focuses on the circuit design and modulation techniques. Yet the claims focus entirely on the escape sequence method--not a single claim relates to the circuit design or modulation techniques! This manipulation of the patent may or may not be within legal bounds, and in any case, that is not the real issue. The escape sequence with guard time may be clever, but it is far too simple to deserve patent protection. Furthermore, it is not the basis of Hayes' success, nor was it the subject of great investment by Hayes. Hayes established a standard software interface, and other modem vendors had to follow this interface to be compatible with existing communication software. Patent protection should not be allowed for interface definitions such as this so that the marketplace can benefit from compatible products. --------------- Michael Slater, Editor and Publisher, Microprocessor Report mslater@cup.portal.com 707/829-4743 fax: 707/823-0504 874 Gravenstein Hwy. So., Suite 14, Sebastopol CA 95472
harkcom@spinach.pa.yokogawa.co.jp (Alton Harkcom) (05/23/91)
In article <42438@cup.portal.com> mslater@cup.portal.com (Michael Z Slater) writes: =} [Hayes patent info & comments] Long ago, one got ones friends together and borke the legs of the competition or wandered the neighbourhood collecting protection money. Now one hires a suit and lets the courts do the dirty work... Al