What Is a Patent, and What Does It Do for Me?

A patent is a right, granted by the government, to a person or legal entity (partnership or corporation). A patent gives its holder the right to exclude others from making, using or selling the invention "claimed" in the patent deed for 20 years from the date of filing. (For patents issued before June 8, 1995, 17 years from the date the patent was issued by the U.S. Patent and Trademark Office.) Once the patent expires, the invention covered by the patent enters the public domain and can be used by anyone. The scope of a U.S. patent is limited to the borders of the United States and its territories.

The right of exclusion given to a patent owner can best be thought of as an offensive legal right. This right of exclusion allows the patent owner to file a lawsuit in federal court against an infringer (anyone who violates the right of exclusion). Because the right of exclusion is not a defensive legal right, the patent owner can't rely on law enforcement agencies to automatically prosecute someone who infringes (copies) his or her patented invention.

For more information about how to complete and file a patent application, see Patent It Yourself , by David Pressman (Nolo).

In the sense that a patent gives the patent holder the right to sue anyone who tries to develop, use or manufacture the invention covered by the patent, the patent can be a valuable commodity. It can be sold outright or licensed in exchange for a royalty. Additionally, the patent owner may choose to manufacture and distribute the invention, thereby keeping all the proceeds for him or herself.

For more information about licensing inventions, see License Your Invention , by Richard Stim (Nolo).

For more information about trademarks, trade secrets and copyrights, consult the following resources: Trademark: Legal Care for Your Business & Product Name , by Kate McGrath and Stephen Elias (Nolo), Patent, Copyright & Trademark , by Stephen Elias (Nolo) and The Copyright Handbook , by Stephen Fishman (Nolo).

1. Categories of Patents

There are three main types of patents: utility patents, design patents and plant patents. In this book, we will focus on utility patents because they are more common. Not surprisingly, a utility patent covers the functional aspects of an invention. As an example, assume that the hammer hasn't been invented yet. Ivan Inventor conceives of the hammer as an invention after he accidentally smashes his thumb with a rock he was using to pound a square peg into a round hole. If Ivan applies for a patent and his patent application describes his hammer invention in general enough terms, the patent would cover all variations of the hammer as a utilitarian device. It would cover common household hammers, sledgehammers, rubber hammers and the like. Perhaps even hydraulic hammers would be covered.

A design patent only covers the appearance of an invention. In our example, Ivan might apply for a design patent for a hammer with a horsehead etched into the shaft of the hammer. Removal of the horsehead would not affect the utility or functioning of the hammer. Design patents are easy to work around. A competitor could design a hammer with a slightly different horsehead (longer mane or bigger eyes), and the new hammer design most likely would not infringe on the original design patent.

Plant patents are for new types of plants. Because plant patents are uncommon we don't cover them in this book.

2. Patent Eligibility Requirements

In order to get a utility patent (as opposed to a design patent), your patent application has to satisfy four legal criteria. (Novelty, unobviousness and other patent requirements are discussed in greater detail in Chapter 10.)

1. Your invention has to fit into an established Statutory Class.
2. Your invention must have some Utility. In other words, it has to be useful.
3. Your invention must have some Novelty. It must have some physical difference from any similar inventions in the past.
4. Your invention must be Unobvious to someone who is skilled in the appropriate field.

In order to fit within an established Statutory Class (the first legal criterion), your invention must be either a Process, a Machine, an Article of Manufacture, a Composition of Matter or a New Use invention.

• A Process is just the performance of a series of operations on something.
• A Machine is a device consisting of a series of fixed or moving parts that direct mechanical energy towards a specific task.
• An Article of Manufacture can be made by hand or machine. As opposed to machines, Articles of Manufacture are inventions that are relatively simple, with few or no moving parts.
• A Composition of Matter is a unique arrangement of items. Chemical compositions such as glue and plastics are good examples of compositions of matter.
• A New Use process is simply a new way of using an invention that fits in one of the first four statutory classes.

The second criterion your patent application has to satisfy is that it must be useful. Fortunately, any new use will satisfy this requirement. In general if your invention is operable (if it functions), it will satisfy this requirement.

The next requirement is Novelty. To get a patent, your invention must be somehow different from all previous inventions documented in the prior art. Generally, there are three types of difference categories.

1. Physical differences between your invention and previous inventions.
2. New combinations made by using previous aspects of two or more different inventions.
3. A new use of a previous invention.

As mentioned, your patent will also have to be deemed unobvious. This is the toughest of the patent requirements. Essentially, what it means is that your new concept must be a significant step forward in the field of the invention. In other words, if a skilled worker who is thoroughly familiar with developments in the area of your invention would consider the idea obvious, you would fail this test.

3. The Patent Document

In one sense a patent is an abstract notion. The PTO issues a patent. The patent gives you certain affirmative rights. The patent expires in 20 years. You can sell or license your patent. In all these uses, the term patent is an abstraction. In reality, the terms of a patent are spelled out in a document called a patent deed that is produced by the PTO. More commonly, the patent document is simply referred to as a patent or patent reference. The patent database consists of hardcopy, microfiche or electronic copies of patent documents.

Every utility patent document, which we'll simply refer to as a patent from this point on, has several identifiable fields or sections. Understanding the different parts of the patent will be especially important when we cover computer searching. This is because we will conduct our search in certain subsections of the patent, and it helps to know what sort of information to expect to find there. Below is a table showing the typical sections that appear in a patent, along with a brief description of what is in each one.

Our table introduces us to several terms commonly used in the patent world. "Class" and "subclass" refer to the complex system used by the PTO to categorize each and every patent that it issues. Conceptually, the system is similar to an alphabetical library index file. For example, to search a library for a book about baseball, one would first go to the subject card index. In the file drawer for subjects beginning with the letter S, you would most likely find a Sports section. Under the sports section, you would go to the subsection for Baseball. There you would find the titles of several books related to baseball. The PTO currently has over 100,000 classes and subclasses.

An "abstract" is simply a summary of the most important features of the invention covered by the patent. The abstract appears on the front page of the issued patent. Patent searchers consult the abstract to get a quick overview of the invention. This in turn helps them decide whether it is worthwhile to review the entire patent. The abstract is the searcher's way to separate the wheat from the chaff. Figure 1 below shows a typical abstract. This is from patent # 5,712,618, an automatic turn signaling device for vehicles.

Figure 1

The "background of the invention" is a discussion of previous inventions that are related in some way to the current invention. These inventions are known as the prior art of the current invention. These previous inventions may embody some of the same or similar elements as the current invention. For example, sprinkler systems and fireproof blankets are two vastly different products. However, they are both related by the fact that they are fire suppressant devices. So, if you invented a modern-day fire suppression device (for instance one using nanotechnology -- tiny microscopic machines -- to deprive the fire of oxygen), both sprinkler systems and fireproof blankets would be considered prior art related to your invention.

Figure 2

Figure 2, above, shows the first two paragraphs from the background section of patent number 5,712,618. The first paragraph is a general summary of the background of the invention. The next paragraph begins the discussion of the advantages of the current invention over previously patented inventions.

Prior art is not limited to inventions patented in the U.S. Patents issued in other countries are considered valid prior art, and, if you apply for a patent, will be compared against your invention. Also, any other published information, from any corner of the globe, can prevent a patent from being granted. Even unpublished works, such as a Master's thesis, can be considered valid prior art. In Chapter 10 we explain how to evaluate your invention in light of the relevant prior art.

The "detailed description of the preferred version of the invention" ( embodiment in patent terms) is a detailed description of an actual, "nuts and bolts" version of the current invention. It is essentially the inventor's best-guess (preferred embodiment) description of the product, at the time the patent application is written. By reading the detailed description, a person who is familiar with similar products should be able to build and operate the current invention. It is important to note that the legal scope of the patent is not defined (the language of patents calls it "limited") by the details of the description of the preferred embodiment. Rather, the scope of the patent is determined by the "claims" (see below).

Figure 3, below, shows the first paragraph of the detailed description of the preferred embodiment for patent number 5,462,805, a fire safety glass panel. Reading through the description we see that specific numbered elements of figure number 1 ( from patent 5,462,805) are referenced. This figure is shown as Figure 4 below. Here we have a glass plate (element 10), another glass plate (element 11), an intermediate resin layer (element 12), and first and second adhesive layers (elements 13 and 14). By following along with the detailed description, and matching the numbered elements of the description with the labeled elements of the drawing, a person familiar with fire safety glass would be able to construct this invention.

The "claims" of the patent are a series of tersely worded statements that precisely describe and define the underlying invention. As we suggest in the chart, patent claims operate in much the same way as do real estate deeds -- they precisely delimit the scope of the patent in the same way as the real estate deed describes the precise location of the property.

From the patent applicant's viewpoint, the claims should be as broad as possible, thus covering many possible versions of the same basic invention. Broad claims make it difficult for someone to defeat the patent by making a minor change to the invention. On the flip side, if patent claims are too broad, there is always the possibility of someone finding a previous invention (prior art reference) that falls within the patent's scope. This could make the patent susceptible to being ruled invalid if the patent holder ever finds it necessary to bring an infringement case.

Figure 5, below, shows the first claim from the fire safety glass patent (5,462,805). While calling out the same elements of the invention as described in the preferred embodiment, the specific element references have been omitted. This is because the claim is meant to be general enough to include different designs based upon the same invention concept.

Also note that here the glass plates are referred to as "low-expansion crystallized glass." This is broad enough to include many types of glass that do not readily expand when exposed to heat. If a specific type of low-expansion glass were claimed, then the patent could be "worked around" by simply claiming a different type of low-expansion glass.

Understanding How Databases Are Created

The PTO has created an electronic database consisting of patents issued since August, 1971. This database can be searched by computer and patent text data can be extracted and examined. However, the data records are incomplete between the years 1971 and 1975. Not all of the patent text data was captured electronically during that time.

In order to get the most benefit from a word-based computer search, it is useful to first understand how searchable databases are put together. Creating a computer database is basically a two-step process. First, the information has to be entered into the computer. Then, the information has to be processed by a special kind of computer program so that the information can be easily retrieved in a meaningful form.

There are generally two ways to get information into a computer (not including voice recognition hardware and software, which is still not commonly used). Someone can physically type the data in at the keyboard, or a person can make use of a device called a scanner. A scanner is similar to the everyday copy machine. A page is placed on a surface and a machine records an image of what's on the page. However, when a scanner is connected to a computer, it is possible to capture an image of a document and store that image on the hard disk of the computer.

When a document is scanned into a computer, it may take one of two forms:

• an image, or
• text that has been extracted from the scanned document by software known as OCR (Optical Character Recognition).

For the purpose of searching by computer, there is a big difference between an image of a document that hasn't been subjected to OCR software and the text that an OCR scan produces. If, for example, a patent is scanned into a computerized database without OCR treatment, the contents of the image can't be searched; after all, it's just a picture. The computer has no way of knowing what the picture contains. You can pull up the patent on your computer screen the same as any other graphical image, but you can't search for the patent according to the words contained in it. However, if the text in the patent document is read by an OCR program before it makes its way into the database, the database will be able to index the text and pull up the patent document according to the words contained in a keyword search.

The database that gets created as a result of OCR processing (or of text that is manually entered or already in computer-readable form) is essentially a huge lookup table. The program that builds this table searches through all the entered text and extracts all the meaningful words. Then, these words, along with a link to the original document they were found in, are placed in the lookup table.

When you use a computer program to perform a word-based search, the program matches the search words you type in with words stored in its lookup table. The search words that you enter are called "keywords" and the search process is called a keyword search. If the computer finds a match, the program will report back to you the document in which the word was found and, in some cases, the location of the word within the document.

The lookup table ("database" in computer talk) is similar to indexes found in the back of many books. In book indexes, words are listed alphabetically, along with a comma-separated list of each page in the book where the word was used.

Understanding Keyword Searching

When you use a computer program to search for patents, you often must search for them by entering words into a "query" box and asking the search program to match your words with words stored in its database.

As you might expect, performing keyword searches is a skill with a learning curve. Sure, anyone can put one or two words into a box and pull up all the patents with those words. No skill there. But the overall number of patents you pull up is likely to be huge and the number of the patents that are relevant to your search are likely to be low. To pull up a manageable number of patents and to assure that most of them will have some relevance to your own invention, you will need to know at least some of the basic techniques for choosing your search terms and combining them into meaningful search queries.

1. The Role of Wildcards in Keyword Searching

One powerful tool that is often used during keyword searching is called the wildcard. A wildcard is a special character inserted into your keyword. This character tells the computer search program to do something special with the keyword within which it's used. The two most often used wildcard symbols are the asterisk (*), and the question mark (?).

The asterisk wildcard is used at the end of a word root to take the place of any number of additional letters that may come after that root. For example, assume you have invented a new type of dance shoe. The shoe can be used for ballroom, ballet and tap dancing. In addition to the keywords "ballroom," "ballet" and "tap," you will certainly want to search for the word "dance." But there are several variations of the word "dance," "dancing," "dancer," "danced," and even "danceable." By using "danc*" as your keyword, the asterisk replaces any other possible characters that would follow the four letters, "danc."

Figure 6, below, contains the search results from searching the titles of U.S. patents issued in the years 1997-1998 for the word "dance." The patent titles that have the word "dance" in them are listed and numbered. As you can see, there are four patents that have the word "dance" in the title. The first title relates to a dance practice slipper, the second title concerns the sole of a dance shoe, the third title relates to a type of dance and the fourth title relates to a portable dance floor.

Figure 7, below, contains the search results from searching the titles of U.S. patents issued in the years 1997-1998 for the word "danc*." As you can see, we now have eight patents listed. The first two titles are the same ones that we obtained before. However, title numbers 3 and 4 contain the word "dancing" as opposed to "dance." The first four letters (danc) are the same as in the word "dance," but the wildcard (*) was used for the letters "ing." Similarly, title numbers 5 and 8 contain the word "dancer," as opposed to "dance." Here, the wildcard (*) was used for the letters "er."

The question mark (?) wildcard can be used to replace any single character in a word. Continuing with our dancing example, the words "foot" or "feet" could be searched by using "f??t" as our keyword. Obviously, you would not want to use the keyword "f*," as this would return every word that started with the letter "f." By using "f??t," every four-letter word that starts with "f" and ends with "t" would be searched for by the computer. For example, along with the words "feet" and "foot," the words "flat" and "fast" would also be reported to you in the search results.

In Figure 8 below, we show a portion of the search results obtained from the IBM electronic patent database when searching for the word "f??t" in patent titles for the years 1995-1998. The first patent (Patent Number 5,697,106) contains the word "foot" in the title, whereas the next patent (Patent Number 5,696,529) contains the word "Flat" in the title. The third and fourth patents listed have the word "Fast" in their titles. Finally, the fifth and sixth patents listed (Patent Numbers 5,695,527 and 5,695,526) contain the word "foot" in the title.

There are other wildcards used on the various computer search systems available to the public. However, the asterisk (*) wildcard is, by far, the most popular.

2. The Role of Boolean Logic in Keyword Patent Searching

A search technique known as Boolean logic can be used to combine individual keywords into powerful searches. Boolean logic uses a total of four words (called "logical operators") to define the search: AND, OR, XOR and ANDNOT. The AND operator is by far the most useful. A graphical representation known as a Venn diagram will help you to understand how these operators work.

In Figure 9 above, we have a circle that has been shaded. The area inside the circle represents all of the patents that contain the keyword represented by the letter A. The area outside the circle represents all the other patents that do not contain the keyword represented by A. In other words, if we were to search a database of patents for all the occurrences of the keyword A, our search results would be contained in the shaded circle above.

In Figure 10, we have two keywords represented by the circles A and B. Searching for individual occurrences of the keywords A or B would result in a lot of search results. It would take a long time to review these results and most of them would be irrelevant.

For example, let's suppose we have an invention idea for a new type of telephone cable. A search for the keyword telephone would return numerous references to different types of telephones. Similarly, a keyword search for the word cable would return patents related to cable television, bridge support cables, cable cars and so on. What we need is a way to search for both the keywords telephone and cable within the same patent. This is where Boolean operators come into the picture.

3. The AND Boolean Operator

In Figure 11 above, we have used the Boolean operator AND to combine the keywords A and B. The shaded area where the circles overlap represents the search results that contain both keywords A and B. As you can see, the AND operator is a great way to narrow the scope of the search.

When a match is found between a keyword (or a combination of keywords) and a patent, the result is called a "hit." When patent searches are conducted, the number of hits, or occurrences, of a keyword match is usually reported to the user. By using the AND operator, the user reduces the quantity of hits that need to be reviewed.

For example, let's suppose that you have invented a new type of steam engine. A steam engine is a machine for converting the heat energy in steam into mechanical energy by means of a piston moving in a cylinder.

The search results using the keyword Engine are shown in Figure 12 above. The shaded circle represents all of the patents that contain the word Engine. This could be quite an extensive list. For example, all the various types of internal combustion engines would be included in this list. A steam-powered vehicle is an external combustion device; the steam is usually obtained from an external boiler. However, if we only searched for the word Engine, we would have to review search results that contained references to gasoline-powered engines for cars, trucks, trains and all other engine-powered devices.

Figure 13 above shows the search result obtained when using the Boolean AND operator to combine the keywords Steam and Engine. The resulting number of hits is represented by the small shaded area in the diagram, where the two circles overlap. We can see at once why AND is the most often used Boolean operator. It allows the searcher to narrow the scope of the search and obtain more meaningful results.

In Figure 14 above, we see the results of a search using the keywords Steam, Engine and Car. In this case the overlapping area is even more precisely defined. It would be necessary for a patent to contain all three keywords before being reported as a match.

Throughout this book, we will identify critical concepts used for effective patent searching. We call these concepts Searcher's Secrets. The use of the AND operator brings us to Searcher's Secret #1.

4. The OR Boolean Operator

In Figure 15 above, we have used the Boolean operator OR to combine the keywords represented by the letters A and B. The shaded area within the circle labeled A represents all of the patents that contain the keyword represented by the letter A. Similarly, the shaded area within the circle labeled B represents all of the patents that contain the keyword represented by the letter B. When you use the Boolean OR operator, you can't tell from your search results whether a particular reference contains just one of your key words or both. Using our Venn diagrams to represent one possible set of search results, we see that in Figure 15, above, there were no hits that contained both of the keywords represented by the letters A and B. If the search results did have some patents that contained both keywords, the resulting Venn diagram would look like Figure 16 below.

In Figure 16 above, we have the two circles, A and B, with a small overlapping area. The lightly shaded areas of A and B that do not overlap represent patents that contain only one of our keywords. The heavily shaded, overlapping area represents patents that contain both keywords.

Returning to our steam engine example, Figure 17 represents the number of hits returned when we use "Steam OR Engine" to search the patent database. What this means is that any patent that contained the word Steam or the word Engine would be returned as a match. The lightly shaded areas of the circles represent patents that contain the keyword Steam or the keyword Engine, but not both. The heavily shaded area, where the two circles overlap, represent patents that contain both keywords. Remember, however, that you couldn't tell this from your research results; the Venn diagrams are only being used to explain what happens in fact. Use of the OR operator brings us to our next Searcher's Secret.

5. The XOR Boolean Operator

The exclusive OR operator is symbolized by the XOR letters. This operator is very similar to the OR operator, but with one important difference. The overlapping area is not included in the search results. So, if we used "Steam XOR Engine" to search our database, we would obtain a list of patents that contained the word Steam, or the word Engine, but not both. This brings us to our third Searcher's Secret.

6. The ANDNOT Boolean Operator

The final Boolean operator we will be reviewing is the ANDNOT operator. The ANDNOT operator is actually a combination of the AND and NOT operators. The NOT operator, by itself, simply finds all the patents that do not contain the keyword used. The reason the NOT operator is combined with the AND operator can be seen in Figure 19. If you were to use the NOT operator, by itself, with just the keyword Engine, your search results would include all the patents that do not contain the word Engine -- a very large search result indeed.

An example of the correct use of the ANDNOT operator is shown below. If you wanted to search for steam engines used in all devices except trains, you could compose a query like:

(Steam AND Engine ) ANDNOT Train

This would return patents concerning steam engines in cars, boats, etc. However, any patent containing the word Train would be excluded. This is true even if the words Steam and Engine were contained within the train-related patent. Figure 20 below shows the search result obtained when using the above query. The resulting number of hits is again represented by the small shaded area in the diagram where the circles representing the keywords Steam and Engine overlap. However, a small section of that overlapping area has been excluded. This excluded area represents the patents that contain the keyword Train.

Use of the ANDNOT operator brings us to our next Searcher's Secret.

7. Use of Parentheses

Also, notice that we have made use of left and right parentheses -- ( ) -- around the words Steam and Engine. This means that the words within the parentheses are evaluated first, then the ANDNOT condition is applied.

We will cover the use of parentheses for advanced keyword searches later in this book (Chapter 6).

You can also combine wildcards with Boolean operators. To return to our dance shoe example, we can combine the keyword "danc*" with the keyword "Shoe," and exclude the keyword "Tap" with the following query.

(Danc* AND Shoe) ANDNOT Tap

The resulting patents would have the words "shoe" and one or more words like "dancing," "dancer" or "dance," but not the word "tap."

Summary

What Is a Patent, and What Does It Do for Me?

• A patent is a right of exclusion, granted by the government, for a term of years. It is a document as well as an abstract right.
• A utility patent covers the functional aspects of the invention. A design patent only covers the appearance of an invention.

How Keyword Searches Work

• A computer program matches the words you type in (keywords) with words stored in its database.

How Wildcards Work

• The asterisk (*) wildcard can take the place of any number of letters following its location in the word.
• The question mark (?) wildcard can be used to replace any single character in a word.

Boolean Logic

• Use Boolean logic to combine keywords into powerful searches.
• The more keywords used with the AND operator, the smaller the number of matches obtained and the more meaningful each match is to the searcher.
• The OR operator is used to widen the scope of the search results.
• One, and only one, of the keywords combined with the XOR operator will appear in each of the patents in the search results.
• The ANDNOT operator is used to exclude keywords from the search results.
• Left and right parentheses -- ( ) -- are used in complex Boolean logic to determine which terms are evaluated first.
• You can also combine wildcards with Boolean operators.