Minelab MPS patent could be invalid

[Zed,]

The grinding of the chips and the paint maybe to stop a competitor finding a critical component and then buying all the stock forcing m/lab to do a re-design.

Zed

[Unregistered]

The schematics and timings for the SD2000 are on this site. The late sample taken in the GB channel is so far removed from being influenced by the short pulses of channel 2 it's only use is to remove Earth Field.

regards
bugwhiskers

So looking at the mixers on page 2 of schematic part 1 PDF we have six mixers 2 each for GB, CH1, CH2.

The signals from the RX coil go to mixers (we will call them) GBb, CH1a, CH2a, at the same time equal amplitude and 180 Degrees out of phase signals go to mixers GBa, CH1b, CH2b.

The inphase and out of phase outputs of GB, CH1, CH2 mixers are added in the pots following the mixers

The early ground return GB samples are summed with the late returns from CH1 and CH2.

The late ground return GB samples are summed with the early returns from CH1 and CH2.

The reason for late return mixing with the early return is the pots on the mixer outputs adjust the slope of the GB correction, simple elegant and I'm glad I didn't have to work it out for myself. Very usefull for cancelling strong magnetec interference and extremely strong magnetic ground which will mask early return from non ferrous metals, it will also help discriminate non magnetic targets from ferous metals to an extant . Keep in mind the lock amps act as very narrow band filters and will cancel out out of band of interefence such as the earths magetic field if the correct frequencies are chosen, your milage may vary.

GB Samples are drawn from LOW and HIGH transmitter(s) and at a different phase are summed with signals from CH1 and CH2
Only one CH is used at a time. There are separate GB pots for each chanel.

Ch1 is an all metal mode standard PI and samples only at the LOW frequency but uses GB signals from both LOW and HIGH transmission frequencies. Since CH1 is lower in frequency it may have deeper penetration. Note that the GB samples are on a 3rd sample interval.

CH2 does the same as CH1 except it samples LOW and HIGH frequencies. CH2 uses the same GB Sample rate and slope as CH1 but can have a differnt level cf CH1

Note: TWO frequencies are transmitted.
Note: CH2 samples (mix is another term for sample since a mixer is just a switch) at TWO Frequencies. The two samples can be subtracted by adjusting the pot on the CH2 demodulator but not at the same point as Poole does after the LP filters a trival shift since it could be done after the LP filter at greater expense.

That is the TWO frequency ground cancellation model that Pool uses if one were to use as he suggests pulse transmitters.

The SDNNNN "GB signal" is a parallel and duplicate circuit (on a 3rd sample interval) but still drives a summing circuit with either CH1 or CH2 signals and the sum of the difference from TWO separate transmission frequencies provides the MD output.


OK lets deconstuct this.

Throw away CH1 which BTW would have been a patentable idea in its own right since it uses the GB signal from both LOW and HIGH frequency transmitters but not the target response to the HIGH frequency transmitter.

Throw away half the mixers from the GB1 and CH2 lock in amps which again is a beatiful eloquent slope compenation scheme I wonder if anyone else thought of that?

What are we left with?

A LOW and a HIGH Frequecy transmitter (and please don't tire me disputing this obvious fact a diplexor can be 3 resitors or a nand gate)

A LOW and HIGH Frequency Demodulator

A summing circuit that is set for no output in the presence ground

When a metalic target with different properties to ground is placed near the coils ....alarm.

Due to?

The fact that each frequency produces different returns for ground and a metallic target and the difference between those returns (due to frequency only) is what is causes the alarm.

Refinements may need to be made to that very basic model for it to be really useful.

Any mistakes please PM unregistered user.








.

[Unregistered]

your milage may vary on NAND gates too <sniker>

[Unregistered]

I'm seeing errors to my post

"GB Samples are drawn from LOW and HIGH transmitter(s) and at a different phase are summed with signals from CH1 and CH2


should of course be

GB Samples out of phase with the transmitters but in sync are drawn from LOW and HIGH Reciever(s) and at a different phase and amplitude depending where the GB pot is set are summed with signals from CH1 and CH2

[Carl-NC]

Where is the evidence that Robby_h knows what he is talking about!

This has prompted me to disable unregistered posting.

[unregistered_user]

I'm seeing more errors "magnetic ground" should be called something else .
"in sync " should be "delayed by x degrees sync" etc.

Now the question remains:
How if not using claim 1 in Pooles patent could "ground signals be substantially cancelled" by using TWO transmit frequencies and TWO recieve demodulators?

The claim of course up until now could rely on the out of phase modifications of the TWO transmitter signals that feed the TWO demodulators which the SD2000 of course does and state that it is an improvement to Poole's method, which in my humble opinion seems to have been dismissed. IANAL so fire away.

Bugwhiskers I re-read your comment regarding the late sample on HIGH frequency demodulator for the GB circuit only removing the Earths magnetic field and I agree that would work in theory as well, has that been patented?

I'm keepin a chinese wall on the minelab patent for a while although I've read a press claim that states there was a "Eureka" moment, I'm sure you're familiar with it. What was the life of a patent in England circa 1978?

[Fred]

This has prompted me to disable unregistered posting.

This will make this thread more interesting, untill now it was impossible to know who was saying what to whom, so reading it was useless.

[Qiaozhi]

This will make this thread more interesting, untill now it was impossible to know who was saying what to whom, so reading it was useless.

I'm not surprised you were confused.

There were 7 different unregistered users active, plus 2 more registered users who occasionally didn't log in. Perhaps this thread will now return to normality.

[hobbes_lives]

This has prompted me to disable unregistered posting.

Thanks Carl.

[unregistered_user]

Further thoughts:

Now since the treatment of the demodulator Local oscillator signal in phase and time and therefore frequency/period (poole already treats phase) between the TWO transmitters and the TWO demodulators is the key difference between the two patents (And I've only read Pooles) What NOVEL claims did Candy make with respect to those frequencies / timing?

The black box if you like, that could be added to Pooles REVOLUTIONARY patent to give it wings?

In fact the SD 2000 uses 2 different (ok CH2 is mayby one) frequencies for each mixer GB CH1 CH2 ( 180 degrees out of phase with the transmitters and all a multiple harmonics of the lowest period/frequency LOW transmitter) for a total of 5 or 6 if you count the CH2 LO Freq as 2 frequencies

But lets just have another look at Pooles model and compare to the SD2000

using CH2 with TWO Transmitters and TWO demodulators so what needs to be done to the path between the TWO Transmitters the phase shifter(s) and the TWO demodulators?

That black box is going to look like 2 multipliers and 2 phase shifters for each of the TWO transmitter frequencies.
So 2 mult. and 2 phase shift paths from each TX into 1 180 degree phase shift box then into the demodulators

Lets call that the "candy box."

Now again full credit to BC for the "candy box" both for the original use of anothers patent which could have been easily accredited quite safely I think ...maybe IANAL.

So any new claim must state what the purpose of the "candy box" is and why it is substantialy different to pooles patent claim number 1.

Perhaps the ability to detect a penny on a plate of steel is just one example I can think of (thanks Roby...oh wait someone else did that already).

Come on guys I'm doing all the heavy lifting here.

What other claims could be made wrt to the "candy box" that would be able to say "ground signals be substantially cancelled" without actually saying "ground signals be substantially cancelled"?

Ideas?

[unregistered_user]

Now for anyone to claim that using a "chocolat box" to improve Pooles patent was infringing another patent the complaintant would have to acknowledge Pooles patented claim 1 in the first place as NOT being a "PI" detector or Pulse transmitter and it would be up to that person to prove Pooles Claim was NOT the same as their own claim.

I would love to see that, imagine the hand waving.

Now since the "GB" circuit on the SD2000 seems only to functionally remove "signals from ground" using the LOW Frequency demodulator (although if the pot range is big enough it could still come into play) that leaves CH2 as the Poole circuit.

Also one could cancel ground using a continously variable pulse width and variable phase (from 180 to 360 degrees out of phase obviously) on ONE or BOTH Frequncies with Pooles circuit but heck he says that anyway (except the pulse width bit).

OK class who wants to come up to the blackboard and draw the "chocolat box" onto the Poole's Fig1 ?

No giggling down the back please I know you ozzies have been out on the town causing a nuisence the headmaster has a full report ...a donkey ...really ntch.


Roby do the honors please, here's the chalk.

[unregistered_user]

Crikey before anyone else says anything ....carry on Roby we're waiting....One could implement an auto-tune by scanning the ground and measuring the slope / exponential decay of the return vs frequency of the return and then do the same for ANY metal you want and ANY metal you dont want and bingo!


HMMMMMMMMM Corbyn did that didn't he? Apart from the auto scan bit he used a fixed ratio.

[Woody.au]

Lets look at the Legal Requirements.. Have they been met?

Requirements to Patent an Invention
Is my idea patentable?

Conditions for Obtaining a Patent

If you want your idea to be patented, you need to meet three legal requirements:
1. Novelty - meaning that the technology is not "anticipated" or identical to an invention disclosed in a single piece of prior art.
2. Non-Obviousness - meaning that the technology must be different enough from the prior art so as to not be obvious in view of the prior art.
3. Utility - meaning that the invention must have a useful purpose. Virtually all inventions meet the utility requirement which has largely been used to prevent the patenting of "quack" inventions such as perpetual motion machines.
A patent cannot cover a pure law of nature or a business idea. In addition, there is a time limitation which may be applicable to a given invention. Under U.S. law, a patent must be applied for within one year of the first offer for sale, public use, or publication of the invention.

[unregistered_user]

Another way of looking at the GB on the SD 2000 circuit is an inverted (in time) "signal with no pulse or background noise signal or noise floor level set allowing the gain after demodulation to be run as high as possible/tolerable" + "ground cancel return" from the LOW frq Transmitter

allowing both noise floor and ground return to be subtracted from the target signals.

So one could automate parameter selection for all values of sampling to all the techniques I've revealed in this and all my previous posts and further signal process those over time for the purposes of "substantially removing ground and or background signals, interference, and metal targets."

I would love to see someone try to patent any of those ideas, my lawyer seems to think this site would qualify as "well known to those skilled in the art" .....you have been warned.

I don't intend to patent the ideas I've discussed obviously.

[unregistered_user]

Lets look at the Legal Requirements.. Have they been met?

Requirements to Patent an Invention
Is my idea patentable?

Conditions for Obtaining a Patent

If you want your idea to be patented, you need to meet three legal requirements:
1. Novelty - meaning that the technology is not "anticipated" or identical to an invention disclosed in a single piece of prior art.
2. Non-Obviousness - meaning that the technology must be different enough from the prior art so as to not be obvious in view of the prior art.
3. Utility - meaning that the invention must have a useful purpose. Virtually all inventions meet the utility requirement which has largely been used to prevent the patenting of "quack" inventions such as perpetual motion machines.
A patent cannot cover a pure law of nature or a business idea. In addition, there is a time limitation which may be applicable to a given invention. Under U.S. law, a patent must be applied for within one year of the first offer for sale, public use, or publication of the invention.

Woody you are not going to believe this but I once knew a guy who.....wait for it....had an actual factual patent for an anti-gravity machine.

Don't get me wrong Candy's patent I think would have still passed muster in 1998 even if he credited Poole (subject to Pooles ascention if he was alive one presumes) BUT THE CLAIM would have to be DIFFERENT and to prevent others from using Pooles patent NOW Candy must now argue WHY.

That may be difficult when it can be shown his patent is substantially the same as pooles and the claim is no DIFFERENT.