CAUTION! CAD Drawings May Be Fatal To Your Design Patent

TASA ID: 370

Most designers working today use a variety of CAD programs to design products and to generate two-dimensional drawings which can be used as the figures in design patent applications.  Is this really a good idea?  A recent experience, when I was retained as an industrial design expert witness on behalf of a Defendant in a lawsuit brought by a Plaintiff who had two design patents and also used some of the same drawings that were registered copyrights, suggests not. 

The background of the case. 

The Plaintiff designed and manufactured an article of furniture that was purchased by an agency of the U.S. Government.  This agency decided they wanted an additional supplier and asked the Defendant to also produce the same article of furniture.  The Defendant obliged and manufactured a first design that was substantially similar to the Plaintiff's design.  Unbeknownst to the Defendant, however, the Plaintiff had obtained two design patents and registered some drawings with the copyright office of their design for the article of furniture.  Upon being informed of the design patents and the copyrights, the Defendant produced a second design that altered the overall ornamental appearance of their article of furniture so it did not infringe the Plaintiff's intellectual property rights.  Nevertheless, the Plaintiff filed suit and brought charges of design patent and copyright infringement against both the Defendant's first and second furniture designs.

It was at this point in time that I was retained in the case and traveled to examine both the Defendant's initial design and the redesigned accused products and form an opinion on whether either of the two designs infringed the intellectual property of the Plaintiff.  Unfortunately, I am not permitted to disclose either of the parties in suit or to reproduce either of the two patents or copyrighted drawings, so for purposes of this article, I have created a portion of the essence of the patented designs and the accused products, using different proportions and geometric forms.  In addition, I have not attempted to draw all of the views and the complete article of manufacture, but have chosen to only focus my efforts on a single view of the design, which should serve as an adequate example to communicate my opinions.

Figure 1 discloses a representative ornamental design of a portion of the Plaintiff's first patented design.  I noted that the patent teaches a pattern of known geometric figures (hexagons) on a surface of indeterminate size and shape since the dashed lines represent an environmental structure that is not part of the claimed design.

Figure 2 discloses a similar ornamental design of a portion of the Plaintiff's second patented design.  I noted that this ornamental design teaches a pattern of known geometric figures (hexagons) positioned on a surface of known size and shape. 

Figure 3 simulates a relative portion of the Defendant's first design.  I note that the patent teaches a pattern of perforated openings of known geometric figures (circles) on a surface of known size and shape.

Figure 4 simulates a relative portion of the Defendant's second design.  I note that the patent teaches a pattern of perforated openings of known geometric figures (circles) on a surface of known size and shape.

  Figure 1          Figure 2

 Figure 3            Figure 4 

After reviewing the evidence in the table above, do you believe either of the Defendant's products infringes either of the two design patents?  

The Infringement Analysis

From the en banc ruling in the Egyptian Goddess case the "test for design patent infringement is whether an ordinary observer, familiar with the prior art, would be deceived into thinking that the accused design was the same as the patented design."[1]  Normally then, the first question that must be asked in an infringement analysis follows: if in the eye of the ordinary observer, with knowledge of the prior art, would an ordinary observer purchase one thinking that it was the other?  It was my opinion that neither the first nor second furniture components infringed either of the two asserted design patents.  Nor, I also concluded, did the Defendant's products infringe the copyrights.

I submitted my expert report to the Defendant's attorneys who in turn forwarded it to the Plaintiff's attorneys.  One week later, the Plaintiff's attorneys filed a motion with the Court to withdraw all charges "with prejudice" (meaning they could not reinstate the case at a later date).

My opinion was based not on my response to the first question posed above, but by asking a more basic question.  What do the design patent drawings teach?  I concluded that the patent drawings teach a pattern of geometric figures printed on a solid surface, and there was no suggestion of openings or perforations as shown in the accused products.  The fact is that all of the drawings in both the design patents and the copyrights were straight forward, unmodified CAD drawings that did not include any surface shading that is required to distinguish between open and solid surfaces in design patent drawings.  The requirements for drawing are quite clear as published in Guide for the Preparation of Patent Drawings, U.S. Department of Commerce, Patent and Trademark Office, October 1993.  ISBN 0-16-042952-8.

    Shading is of particular importance in the showing of three dimensional articles, where it is necessary to delineate plane, concave, convex, raised and/or depressed surfaces of the article, and to distinguish between open and solid surfaces. Transparent and translucent surfaces should be indicated by oblique line shading as shown in appendix 4. (Emphasis added)

Thus, absent any surface shading, the design patents teach a pattern of geometric figures printed or embossed upon a solid surface.  There is no teaching of perforations or openings in a solid surface such as are present in the accused products.

The lesson to be learned from this case is that it is all right to produce CAD drawings as the basis for a design patent application, but make certain that the drawings are modified to conform to the rules of the USPTO, or the design patent may be doomed to protect that which it was intended to protect


[1] Egyptian Goddess 543 F.3d 665, 680  (Fed. Cir. 2008) (en banc).


This article discusses issues of general interest and does not give any specific legal or business advice pertaining to any specific circumstances.  Before acting upon any of its information, you should obtain appropriate advice from a lawyer or other qualified professional.

This article may not be duplicated, altered, distributed, saved, incorporated into another document or website, or otherwise modified without the permission of TASA.

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