Patent Claims - How To Keep Track Of Them

T.W.R. East

ABSTRACT

The claims are a vital part of every patent disclosure, but can be confusing for a non-lawyer to read and understand. They can be analysed in a simple dependency table.

A patent disclosure includes, among other things, a “description of the embodiment,” which reads like a technical article, and a set of claims, which reads like a legal document: the claims often depend on each other in a complicated way. While preparing material for a UK, US and Canadian patent with my patent attorney, I have found the claims to be the most difficult to keep organised: it is only too easy to leave something out, or to get the dependencies mixed up.

Here is a set of claims from an actual patent disclosure (some claims have been shortened, simplified or omitted for brevity).

What I claim is: 1. A system for repeatedly adjusting the phases of the antennas

in a transmitting array in order to maximise the electromagnetic field at a remote target moving relative to said array, comprising

(a) a radio frequency exciter and a plurality of antennas, each said antenna having a controller for controlling the phase of the power radiated from said antenna

(b) waveform generating means at said array (c) timing means suitable for selecting each said antenna

in turn and causing its controller to phase modulate the power radiated by said antenna in response to the

Previously published in Engineering Dimensions, the official magazine of the Professional Engineer’s of Ontario. Reprinted by permission of the author. Author’s Current Address: Tom East Engineering Services, 516 Fallingbrook Drive, Waterloo, Ontario, N2L 4N3, Canada Manuscript received April 21, 1995. 0885-8985/95/ $4.00 0 1995 IEEE

waveform generated by said waveform generating means

(d) detection means to detect the magnitude at said target of the combined field, etc. all said means combining to form a closed feedback loop.

2. A system as in claim 1, in which said phase modulation waveform is substantially a square wave.

3. A system as in claim 2, in which said phase modulation is substantially plus and minus 90 degrees.

4. A system as in claim 3, in which said modulation waveform is random.

5. A system as in claim 3, in which said modulation waveform is pseudo-random.

6. A system as in claim 1, in which each said controller changes the phase of its said antenna continuously to anticipate the required correction.

radiation of microwave power from an array, a system for continually adjusting the phases of the antennas in said array to steer and focus the beam radiated by the array so that it follows the target, comprising

7. In a system for supplying power to a moving target by

(a) a plurality of antennas in an array (b) an exciter generating radio frequency power which is

distributed to said antennas (c) for each said antenna, means to apply said power from

said exciter to said antenna, means for controlling the phase of said antenna to remain constant except when it is selected to be phase modulated

continually and repeatedly

square waveform

phase modulate said antenna rapidly by plus or minus 90 degrees in response to said waveform

(d) timing means to select each said antenna in turn

(e) means for generating a pseudo-random alternating

(f) means causing its said phase controlling means to

32 IEEE AES Systems Magazine, August 1995

Claim number

Depends on claim

Feature

Antenna array

Remote moving target

Exciter

Phase controller

Waveform generator

Timer

Modulator

Detector

etc

Feedback loop

Square wave

90 degrees

Random wavefonn

Pseudo-random

Anticipation

Table 1.

1 2

- 1

Pre

Pre

la)

(a)

(b)

( C )

( C )

(d)

Post

X

Table: Patent c l a h dependency chart Post = postamble

6 7

1 -

X

Pre = preamble,

(g) detection means on said target to detect changes in the magnitude of the combined field from said array etc.

all said means combining to form a closed feedback loop.

The first claim consists of a short preamble, four parts lettered (a)-(d) and a “postamble.” The second claim starts with the words “A system as in claim 1, in which . . .,”indicating that claim 2 depends on claim 1. Similarly, 3 depends on 2 , 4 on 3, and 5 on 3 (not 4). Claim 6 goes back to the generic version (claim 1) with a new departure. The last claim, 7, wraps it up by describing the ‘best” version of the invention from scratch, repeating a selection of the features in the other claims.

I have found it useful to summarise the claims in tabular form (see Table). The left column contains a series of notes of the features in the order they appear in the claims. The other columns are headed by claim numbers 1,2, etc., on the next line under each claim number is the number of the claim on which that claim depends. In the body of the table, whenever a feature is described in a claim, an X is put in that column. When claim N uses the words ‘hs in claim M”a line is drawn down column N to cover everything in claim M, and then an X is entered for the new feature in claim N.

After drawing the table, I check that the left column contains everything in the “description of the embodiment” that I think is novel. Then I look horizontally from each feature to make sure that it is claimed in at least one claim, and that the right features are included in the last (wrap-up) claim.

I have found this method to be useful in checking the wording of my claims, to make sure that everything has been covered and to look for inconsistencies, and also in analysing other people’s patents.

Thomas W.R. East received a B.A. and an M.A. in Natural Sciences from Cambridge University, and an MSc. and a Ph.D. in Physics from McGill University. In the 1940s, he worked at TRE Malvern (UK radar establishment), in the OS, at the Stormy Weather Group (McGill University, Montreal, Canada) and in the 60s through SOS, at Raytheon Canada Limited. He is proprietor of Tom East Engineering Services in Waterloo, Ontario, Canada.

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IEEE AES Systems Magazine, August 1995 33