Patents are government-issued legal documents that give inventors exclusive rights to their inventions.

Everyone's got an idea for an invention - from a treadmill for dogs, a car espresso machine, to a motorized surfboard. Or, a little portable music player, better known as the iPod, by Apple Computer.

Once you have that potential million-dollar idea, what's the first thing you should you do?

As Apple found out, guarding your idea by applying for a patent immediately – a government-issued legal document that gives exclusive use to an invention – is a good idea.

Apple launched the popular device in 2001 and applied for a patent in October 2002. In August 2005, Apple's application to patent the iPod's trademark rotational wheel interface was rejected – because rival Microsoft beat them to it by five months. Tech pundits snickered at the thought of Apple paying royalties to Microsoft on iPods, which account for more than a third of Apple's revenue.

The matter is still being sorted out at the U.S. Patent office, but the lesson is clear – budding inventors should patent their ideas, because saying "I was there first" may not be enough.

What is a patent?

Patents are government-issued legal documents that give inventors exclusive rights to their inventions. They are granted for products or processes that are novel, functional and inventive. Without a patent, anyone can exploit your invention. As well, someone else can patent your invention and block you from profiting from your own idea.

Patents guard ideas, but also are a way of sharing knowledge. Each patent document describes a new way of doing things, and are available for anyone to read through the Canadian Patents Database.

Why should I get a patent? How much protection does a patent provide?

If your invention is successful on the market, a patent will give the holder a monopoly on all the profits.

"Once it's patented, you'll have a marketing advantage… It's worth the money. It's like buying insurance," says Dumitru Olariu, CIPO business development officer and former patent examiner.

This is key because once an invention hits the shelves, copycats can easily figure out how to duplicate the product.

"You cannot keep it a secret," he says. "Though Coca-Cola has kept the composition of their beverage a trade secret, other inventions, once on the market, are not complicated for the competition to figure it out."

What are some famous Canadian inventions/patents?

Some famous made-in-Canada inventions include the telephone, insulin and the revolving snow shovel. In 1874, Alexander Graham Bell invented the telephone, later spawning the telecommunications company that still bears his name. In 1921, two men from the University of Toronto, Dr. Frederick Banting and Dr. Charles Best, isolated insulin, which revolutionized the treatment of diabetes. And J.W. Elliot of Toronto invented the first revolving snow shovel in 1869. It is the basis for many of the rotary snowplows used around the world today.

What are some unusual Canadian inventions/patents?

The mechanical skirt lifter and an artificial heart powered by steam are two. In 1890, a Calgary woman invented the mechanical skirt lifter. It was designed to raise the skirt hem so women could walk across wet or muddy roads without getting dirty. And in 1971, a patent was granted for an implantable artificial heart that ran on a steam-powered engine. Patients' own blood was used to cool the engine.

Canadians aren't the only ones with weird contraptions. Some American inventions include a motorized ice-cream cone and toe-puppets, according to the Crazy Patents website, owned and operated by Neustel Law Offices in North Dakota.

Who enforces the patent?

It's the patent holder's responsibility to enforce it through the Canadian legal system – any court in Canada recognizes the patent. But the Canadian Intellectual Property Office does not police the patent system.

How long is a patent effective?

In Canada, a patent lasts for 20 years after the first application is filed. But since the patent process can take about two to three years, a patent gives you roughly 17 years of protection.

Patent holders must pay maintenance fees throughout the life of the patent to keep it active. After 20 years, the patented idea is considered public domain, and anyone can use it. But, Olariu says, ideas are usually outdated by then. "At the end of its life, the patent becomes less valuable. The technology advances, to such an extent that it is no longer used."

How do I apply for a patent?

Budding inventors need to apply to the patent office of each country where they wish the patent to be held. In Canada, inventors should apply to the Canadian Intellectual Property Office.

How does the process work?

Applicants must submit a petition (the formal request for obtaining a patent), a description of the invention, an abstract, a claim (a concise written statement that defines the invention covered by the patent application), drawings and the filing fee. The Canadian Intellectual Property office has an online tutorial to guide applicants through. In Canada, it works on a first-come, first-served basis – the first inventor to apply gets the patent. If applications are submitted on the same day, the patent is shared. And once the product is on the market, inventors are no longer able to apply for a patent.

How long does it take?

From the moment the first application is filed, to when the patent is granted, it takes about two to three years, says Olariu. He recommends applying for a patent immediately. "Start the process as soon as possible… It's enough time to figure out how to market the prototype. When they hit the market, they have the patent as well."

How much, in total, does it cost?

It could cost anywhere from $200 to more than $30,000. The price depends on a few factors including: how large an organization the patent applicant is, how complicated the invention is, and if the applicant hires a patent agent.

An applicant is considered to be a small entity if it's an organization with 50 or fewer employees, or is a university. If it is larger than that, it falls into the large entity category - for which the application and maintenance fees are double.

Application fees for a small entity total about $750, and $1500 for a large entity.

Maintenance fees throughout the life of the patent are paid annually, and rise in increments over time. For a small entity, it costs about $2,400, and costs $4,800 for a large entity. Then there's the patent agent – a person well versed in the patent process hired by applicants to help process their applications. They are registered with the CIPO, and charge fees ranging from $5,000 to $20,000, depending on how complicated the invention is.

Patent agents will draft, write and process the applications on behalf of their clients. Applicants aren't required to use one, but Olariu says the CIPO recommends using them because the patent process is quite detailed. "If you decide to [apply for the patent] yourself, you better read about the process. For some people, it's a little too complicated."

What are the key factors for approval?

The invention must be new, useful and "ingenious," says Olariu. It cannot be an obvious observation or conclusion for someone who works in that field. Patent examiners are hired for their areas of expertise and can decipher an idea's ingenuity. The product description also needs to be specific. If the patent claim is too broad, it may restrict other inventors unfairly and may not be approved.

How different must my invention be for approval?

It's a grey line, says Olariu, and about 80 per cent of patent approvals are for small improvements. But the small improvement itself has the key factors of novelty, utility and ingenuity. And, he says, a product tweak can have big implications for products, like pharmaceuticals. "You can change just a small amount of the composition, but it comes with unexpected results."

How many patents come through the Canadian patent office? How many are approved?

In 2004-2005, there were 39,640 patent applications, 38,054 in English and 1,586 in French. During that period, 13,553 were granted.

But that doesn't mean the bulk is rejected – about 80 per cent of applications are approved, Olariu says. Some applicants abandon the process before it's complete, he says, because it's too costly or the product isn't suitable for marketing.

"[Products] evolve so rapidly, people are thinking about something else... so they concentrate that effort and money somewhere else."

What fields are patents most commonly applied for?

For 2005, here's a breakdown by type: