Patent on a method for exercising a cat

When you pull out a laser pointer and get your cat to chase the dot of light around your house*, you are using a patented method of cat exercise. The rights are owned by Kevin Amiss and Martin Abbott (both of Virginia), who patented it in the early 1990s. In the abstract, they describe this method of cat exercise as:

A method for inducing cats to exercise consists of directing a beam of invisible light produced by a hand-held laser apparatus onto the floor or wall or other opaque surface in the vicinity of the cat, then moving the laser so as to cause the bright pattern of light to move in an irregular way fascinating to cats, and to any other animal with a chase instinct.

In other words, they own the rights on doing this with ferrets, as well.

This might also be a good time to note an NPR story from this week, which documents IBM and Halliburton attempting to patent the process of patent trolling.

Method of exercising a cat: United States Patent 5443036

*Fact: This game becomes more fun if you have a rug. Just run the light up to the edge of the rug and then turn it off. The cat will become convinced that the little red light has gone under said rug and you will get to amuse yourself watching your cat try to lift the corner of something heavy without the use of opposable thumbs.

Thanks, Sam Ley!

Image: Gotcha!, a Creative Commons Attribution Share-Alike (2.0) image from drregor's photostream



  1. Well, the idea of using “invisible light” is new to me – personally my cats prefer good old-fashioned visible light.  It’s also entertaining for dogs, aquarium fish and praying mantids!

    1. You saw that too huh? Yup, this is a useless patent. There are invisible lasers sure, but my cat refuses to chase them. I don’t see why not. She chases invisible things all the time.

    2. There is one exception: when exercising your domestic Cthulhu, only non-Hertzian frequencies will get the little guy interested. 

      If your optoelectronics vendor of choice doesn’t stock selenium arsenide/color out of space laser diodes, your best choice would be a KTP frequency adjustment crystal cut to provide a noneuclidian beampath(see W. Gilman, Nyarlathotep, et al for details)

  2. I first read that as “exorcising a cat,” but that may be because my grandfather used to insist that cats were evil spirits.

    1. That might make sense with the invisible light – the physical cat doesn’t see the laser, so remains sitting still and semiconscious; the demon sees the laser and impulsively chases it up the side of the fridge before realizing it’s been tricked.  On trying to return to its host body, it discovers the cat is snoozing inside a circle of protection.

  3. This patent expired 8/22/2007 due to non-payment of maintenance fees. I.e., the “inventor” decided it wasn’t worth $2365 to keep the patent alive.

    1.  Maybe they let it go once they realized they’d patented it for “invisible light”.

      “…directing a beam of invisible light produced by a hand-held laser…”

      I’ve tried the invisible light trick and my cat just won’t fall for it.

  4. Several years ago someone patented a method for swinging on a swing just to show the absurdity of the system.  I don’t know if that patent is still around or not, but I’m sure there’s articles about it out there, I may have even seen it on boingboing. 

    1. It’s US6368227.  Thankfully, it was reexamined and cancelled in a little over a year after issuing, but the fact that it issued at all is ridiculous.

  5. I’m going to disagree with your conclusion that  “they own the rights on doing this…”.  The patent 5,443,036 expired in 2007 due to nonpayment of maintenance fees.  The cited patent is expired.

  6. Not that this is news, but the US patent system is mad.

    At least in the UK something has to be ‘novel’ to get patented, i.e. not pre-existing, and it has to require some kind of specialist knowledge (i.e. if that guy in the street could think of it too, then it shouldn’t be patented).  It also has to be outside of public knowledge, i.e. if you tell a friendly reporter about your invention and they print it, no patents for you.

    The fact that you can patent something that people already do and know about or own in the US is completely nonsensical.

    1. Part of the problem could be the fact that the Patent Office collects fees and is encouraged to collect as much as possible.

    2. Both the ‘novelty’ and the ‘non-obviousness’ requirements exist in US patent law as well. It’s a matter of implementation…

        1. I’ve never heard of patent-office slogging being a terribly lucrative ticket to future ‘consulting’ gigs, or a major source of hookers and expensive vacations (unlike, say, the party people at the department of the interior… )

          Given that, I’m going to assume that it’s mostly a situation where the inbox is filling ever higher, you aren’t going to get a medal for most careful scrutiny of a patent application, and far fewer applicants dispute an application you grant than an application you deny. Whether or not that qualifies as ‘laziness’ really depends on how fast the supply of applications vs. the supply of patent examiners forces the examiners to do a somewhat tepid job. Slackers and sweatshop workers both produce lousy product because they don’t put time into their work; but they aren’t exactly equally lazy…

  7. And if you had Schrodinger’s Cat, then the invisible light beam would be simultaneously on and off.

  8. There are at least 5 or 6 “animal/laser/amusement” themed patents in the record, though like this one, some may be expired. There is one for an automated system that moves the laser around for you, and after a somewhat complex description of the apparatus, it goes on to say that you could just mount the laser on an oscillating fan, which would both move the laser around, and provide “convective cooling” for the exercised animal.

    Patents do need to meet certain conceptual requirements of being “novel”, but I fear that, like many parts of a bureaucracy, the actual original requirements often get left aside and it turns more into a game of who can submit the paperwork properly, and who can write in a “patenty” way. You could submit poor paperwork for a cold fusion reactor and it would be denied, but submit something for amusing a cat with a laser pointer with all your t’s crossed and i’s dotted, in perfect “patent-ese” and in it goes.

  9. If IBM can patent patent-trolling, they can kill the practice. I’m sure — and note that I’m _NOT_ being sarcastic here — that this is indeed their goal.

  10. Some friends in the 1970s had hand-held lasers, they were helium-neon tubes.  If they’d only taken photos they could have shown prior art, because they certainly used them to play with their cats.

  11. As the proud owner of 8 ferrets over the years (3 currently) I can happily report that they are not as gullible as cats or dogs – I’ve never seen this work on a ferret (mine or others) but not for lack of trying. 

    I have, however, observed ferrets stealing things from the distracted humans trying to taunt another ferret with a laser pointer.

  12. Most patents never give birth to marketed products. You can get a patent but the value is in the claims the patent examiner permits. Weak claims make the patent worthless. You must claim everything essential to making the device and all other possible combinations even if they aren’t workable in order to protect from infringement. The patent that did all of that was the one for the Gillette Safety razor. The patent battles currently raging are aimed at one company delaying another. One company need only outspend another in paying for legal moves. The merits of the actual patents are iffy at best. 

  13. If most peoples experience of getting patents granted is as unquestioning as all this makes it seem, then the examiner on my patent seemed to do rather exceptionally thorough job challenging us on prior art claims. Just goes to show that the people doing the examining are not all the same and some of them do take their job seriously. Still took five years from application to issuance, tho’.

  14. As a registered patent agent, working on biotech patents, I get a little sick of people making fun of the US patent system, which is actually pretty good in my own experience.

    About the wording “invisible light”, I note first that the writer of a patent application can be his/her own lexicographer – you can define a word any way you want, even in contrary to standard definitions, just as long as you say what you mean in the text of the application.

    Please look at the actual text of this patent (which you can see if you go into PAIR – Patent Application Info Retrieval System – – and typing in the number, 5,443,036).

    What does the patentee mean by “invisible”?  The patent itself tells us: “The light pattern projected by the laser cat exerciser is invisible until intersection with an opaque surface. Lasers emitting various colors of coherent light can be used and the laser apparatus can be distinctively shaped and colored for easy identification.”  A claim also states that the “beam remains invisible between said laser and said opaque surface until impinging on said opaque surface”.  So the laser is invisible until it hits the wall. 

    Please don’t make fun of the wording of a patent’s claims until you actually read the text of the Specification, which may define some of the offending wording.

    Regarding the issue of whether or not this invention was novel, the USPTO will do a search of any written documentation it can find, and then consider whether the invention is novel (new) and non-obvious in light of the written documentation.  If people did this earlier, but it was never documented and that documentation published in an accessible way, then the USPTO has nothing to go on.

    That said, if this were ever litigated (e.g., in a patent infringement lawsuit), the defendant could invalidate the patent if he/she supplied written documentation that this was done earlier. Thus, there is a check in the system.

    Also of note, this patent application was filed in 1993, and the USPTO is today better at finding prior art than ever before (esp. with the ever-expanding internet). 

  15. Wouldn’t a patent issued in the “early 1990’s” be expired by now? 1995 plus 17 years = 2012. Or at least real soon, since 1995 is when we cut over to 20 years from date of filing.

Comments are closed.