Patent Drawings for Design Patent vs Utility Patent: What's the Difference?

When preparing and filing a patent application, you probably know that the written description is not the only thing you need to do properly. In many cases, the drawings, or simply put, the pictures of your invention, can be as important and valuable as the description. In particular, the difference between the design patent drawings and utility patent drawings should be clear, otherwise, your application can be rejected or result in an office action, which will cause delays and cost money. Here, we will tell you more about these differences, how to prepare drawings correctly, and what to pay attention to in order to make everything right. Whether you are an independent inventor, a startup founder, or simply interested in the topic, this article can be useful for you.

Why Do Patent Drawings Matter So Much?

First, it makes sense to talk about why patent drawings are so significant.

There are two types of patents – utility and design. In case of the former type, the claims describe the scope of protection; in case of design patent drawings define the scope of protection. As it was mentioned above, there is a difference between design and utility patent applications: in the case of utility patents, the written claims define the scope of protection; in case of design patents, the drawings do this. The absence of description is the main reason for most differences between design and utility patent drawings – once you understand this basic point, everything else becomes clear.

What Is a Utility Patent and What Does It Cover?

A utility patent is a type of patent that covers how something works (its function, mechanism, structure, or a process). For example, a hinge, a water purification system, the device controlled by the software, or a special manufacturing process. This is the most popular type of patent filed in the US. The term of protection of the utility patent is 20 years from the filing date.

The purpose of the utility drawings is to help the patent examiner (and in case of litigation, judges or competitors) to understand the structure and function of your invention in addition to the written description and claims. The USPTO guidelines state that according to 37 CFR 1.84, utility drawings shall show all features described in the claims and be so descriptive that someone familiar with the relevant technology can understand the structure and operation of the invention after viewing them together with the description of the invention.

Features of Utility Patent Drawings

• Emphasis on functionality: drawings show mechanical parts, internal structure, electrical connections, flowcharts, process steps, whatever shows the functionality of the invention.
• Several types of drawings are possible in a utility application: exploded, cross-sectional, flowcharts, block diagrams, schematics, perspective drawings – whatever can help in explaining the invention.
• Usage of reference numerals is mandatory: each element described in the written description should be marked with corresponding numbered reference numerals (e.g., "10" for the housing, "12" for the motor shaft), and those numerals should be used consistently throughout the whole application.
• Only black and white line drawings are required, though color drawings or photographs can be presented, if a petition (and fee) is submitted, stating that color is necessary (e.g., to show a color change during the chemical reaction).
• Drawing of the surface texture, drawing of shading to show the depth, and drawing of hatching to show the cross-section are usually done to facilitate the understanding of internal mechanisms of the invention.
• No claim to ornamental appearance is included in the utility drawings: no matter whether it looks beautiful or not – only its functionality is protected in such case.

Since utility drawings are only supplementary to the written description, examiners have a bit of leeway to interpret them in conjunction with the specification. An absent or unclear feature of the drawings can be explained by means of the written description in many cases – but not always, especially for the features described in the claims.

What Is a Design Patent and What Does It Cover?

A design patent is a type of patent that covers the ornamental appearance of an article, i.e., its shape, surface pattern, configuration, or visual impression. The operation of the invention is not covered. For instance, the unique shape of the smartphone, the pattern of shoe sole, or the silhouette of a bottle belong to design patents. The term of protection for the design patent is 15 years from the date of grant (not from the filing date). Unlike the utility patents, design patents have no maintenance fees.

Now, pay attention to this: in a design patent application, drawings are the invention! There is no detailed written description of the design features, as in the case of the utility patent – there is a brief, standardized description stating what each figure shows (e.g., "Fig. 1 is a front perspective view of the shoe"). The drawings are the definition of the scope of the protection of the design patent – all lines, all shaded areas, all dotted outlines.

That's why in the case of the design patents the drawings should be very precise and formally executed, since any mistake in shading, inconsistency of views, or unclear outline can decrease or nullify your protection entirely.

Features of Design Patent Drawings

• A view from all sides is required in most cases: front, rear, left side, right side, top, bottom, and perspective view – sufficient amount of views is required to describe the invention in order not to leave any aspect of its appearance ambiguous.
• Surface shading is mandatory in order to depict the three-dimensional nature of the surfaces and their contours and character. Line drawings without shading are almost always rejected by the USPTO unless the surface is truly flat.
• Difference between solid and broken lines is crucial: solid lines indicate the part of the design which is protected, while broken (dotted) lines indicate environmental structure or unclaimed portions of the article (e.g., if the invention is a bottle, the cap of the bottle can be indicated by the broken lines in order to show how the bottle looks with the cap attached).
• Reference numerals for the function are not required in the case of design patents – numbers are used only to indicate figures (fig. 1, fig. 0, etc.).
• It is important that the consistency of the views is mandatory: if a curve is present in the front view, this curve should logically be present in the side and top views. Any inconsistency leads to rejection of the invention as new matter or due to lack of clarity.
• Photographs are permitted in the design application (which is forbidden in the utility patent application), but all figures should be photographs if one figure is a photograph (the photographs should have the uniform professional lighting with the neutral background).

Design Patent vs Utility Patent Drawings Comparison

Comparison Example: Same Product, Different Patents

Imagine you developed a novel type of water bottle, which includes a filtering cartridge inside, and also designed its shape in a unique way. In such a case, it is quite possible that you will want to file both utility and design patents for the same product.

The utility patent drawings will depict the internal filtration mechanism – the housing of the cartridge, the water flow through the cartridge, the sealing mechanism, the threads of the cap – all the drawings will be labeled with the reference numerals and may include cross-sections in order to depict the internal structure.

The design patent drawings will include all six orthographic views of the bottle's external shape, including the shading of the surface in order to depict the bottle's curvature, and the use of the broken lines if, for example, the closing mechanism of the cap is not claimed.

Note that the two different sets of drawings depicting the same physical product differ significantly, because the protection offered differs significantly – one type protects the function, and the other one protects the appearance.

Dual-filing in this way is actually common practice in some product-oriented industries (consumer electronics, footwear, and packaging industries).

Common Mistakes Made When Preparing Patent Drawings

After reviewing and preparing many design and utility patent drawings, there are several common mistakes that seem to recur again and again:

• Design drawings are not made properly. Inventors often submit flat, unshaded CAD outputs for design applications, unaware that the USPTO requires proper shading in order to depict the three-dimensional nature of the surface.
• The inconsistency in the usage of the reference numerals in the utility drawings. If your specification mentions "locking pin (24)", but the drawing shows it as "23" or without a number at all, be ready for an office action.
• The inconsistency of the line types in design patent drawings. If the boundary is drawn with solid line in one figure and with dotted line in another one, expect the rejection of the application for ambiguity.
• The insufficient amount of views in design applications. Applications with front and side views only often fail due to "insufficient disclosure" – it is impossible to describe the 3D shape with limited number of angles.
• The mixed drawing style. Mixing photographs and line drawings in the same design application, or using color drawings in utility application without submitting the required petition – the error that is easy to avoid.
• Ignoring the margin, sheet size, and numbering rules. The drawings of any type should comply with strict USPTO formatting requirements (paper size, margins, figure numbering, sheet numbering), as stated in 37 CFR 1.84 and 1.152. Failure to comply with the formatting requirements results in "Notice of Non-Compliant Drawings" and processing delays.

Why You Should Be Careful About the Differences Between Design and Utility Patent Drawings

Now, it's the part of the information that inventors sometimes overlook: for the design patents in particular, courts have repeatedly stated that the scope of protection is restricted to the drawings only. The ambiguity or inconsistency in the drawings not only causes delays in the examination, but can be used by competitors in order to design around the patent or even invalidate your patent in the case of litigation.

For the utility patents, although the claims define the scope of protection of the patent, courts and examiners often refer to the drawings in order to interpret ambiguities in the claims. Properly drafted and complete drawings can actually strengthen your claim interpretation during the prosecution or litigation, while sloppiness of the drawings can cause misunderstanding to your disadvantage.

And this is the actual reason why the patent professionals emphasize the importance of drawing work so much – it is not about making the drawings look good, it is about defining your invention properly and ensuring the protection of its actual scope of the function or appearance.

Work With Professional Patent Illustrator

Since the rules for the both drawing types are highly technical, and there are severe consequences for failing to comply with these rules, many inventors (even self-filers) prefer to use services of professional patent illustrators specializing in USPTO-compliant illustrations.

A good patent illustration service usually:

• Translates your invention disclosure or CAD drawings into the USPTO-compliant drawings with properly labeled parts, for the utility patent applications.
• Ensures the consistency of the reference numerals in the drawings for utility patents.
• Uses proper solid and broken lines conventions for the design patents, in order to depict what you intended to claim.
• Formats everything in accordance with the required size, margin and numbering requirements, in order to avoid the "Notice of Non-Compliant Drawings" notice.
• Coordinates with your patent attorney or agent to ensure the consistency between drawings and the written claims or figure description.

If you file your application in foreign countries as well (e.g. through the Hague System for design patents or the PCT for utility inventions), then the drawing requirements may be slightly different in different jurisdictions – that's why the professional assistance is beneficial in such cases.

FAQ

Is it possible to use the same drawings for the design and utility patent application?

Well, generally no, not directly. Although you can file both types of patents for the same invention, the drawings should be created taking into account specific requirements of the patent types – the utility drawing, depicting internal structure and labeled with reference numerals, will not be compliant with the requirements for design patent application, and vice versa.

Does a design patent drawing have to show the invention in use?

No, not necessarily. Usually the design applications show the article by itself from all the sides. However, in some cases, it is possible to add a drawing showing the article in the environment (in such case broken lines are used for the depiction of the environment).

What will happen if the USPTO rejects my drawings?

Usually you'll receive a notice of non-compliant drawings or office action pointing out the specific reasons for the rejection (missing views, inconsistencies in the line types, wrong reference numerals, or incorrect formatting). Then you will be able to submit your corrected drawings in the specific timeframe provided.

Are black-and-white drawings required?

Yes, in most cases: color drawings are allowed only with an approved petition and fee (reserved mostly for biotech or chemical applications), in case of utility patents. In case of design patents, black-and-white drawings or photographs are standard – but in some cases color photographs are allowed too, usually also requiring petition.

Can I prepare my drawings myself instead of using a professional illustrator?

Yes, you can, technically speaking – the USPTO doesn't require you to use a professional draftsperson. However, in light of the technical nature of the requirements and legal consequences of improper or non-compliant drawings, especially in the case of the design patents where the drawings define your protection scope, many inventors find that professional illustration pays off. This has a direct impact on the strength of your patent protection, the ease of processing your application at USPTO, and the durability of your rights in case you ever have to use them for enforcing purposes. Regardless of whether you are applying for a utility application for your new mechanism or a design application for your product's unique appearance, putting time (and sometimes, professional effort) into drafting quality drawings is one of the best decisions you can make during the entire patent process.

When you are going to prepare an application of any kind, it may be useful to discuss your invention with a professional who will be able to help you decide which type of drawings you will need and whether you need both types of drawings or only one.