A well-drafted patent application is key to securing strong IP protection, but clarity is just as important as innovation. Any application that fails to clearly and concisely explain an invention risks office actions or even rejection. This is where patent diagrams play a crucial role, visually communicating intricate details of a product, process, or design to the examiner. Adherence to IP office requirements is essential with many jurisdictions mandating diagrams in both utility and design patent applications. Even a minor flaw or miscalculation can lead to costly delays, wasted effort, and increased expenses. This article explores the critical role of patent diagrams, their various types and views, the importance of hatching and shading, common challenges, and the rules that govern their use.
Relevance of Patent Diagrams
Patent applications contain graphics, also known as patent diagrams, illustrating the inventions, their embodiments (process or methods of carrying out invention), or the prior art. They are drafted manually or using modern tools to explain the invention better for an ordinary observer and examiner. A neatly drawn patent diagram also assists in eliminating ambiguity about the novelty of the inventions that may not be clear after reading the claim text.
A patent application in the US requires a minimum of one patent diagram (also referred to as a patent illustration/diagram) to represent the invention graphically. With patent diagrams, the inventor can demonstrate exploded views (shown in Figure 1) that facilitate explaining how the pieces and parts fit together. Such views make it easy for a patent attorney to understand and elucidate the invention step-by-step. If the written disclosure lacks crucial details, a well-detailed diagram can compensate by capturing the subtle aspects of the invention.
Figure 1: Exploded View of a Lawnmower Blade with Replacement Knives
In addition, the surest way to increase the scope of any application is to file multiple, professional, impeccable diagrams. It is a good practice to include patent diagrams in your application, or one may not even get a filing date, which can be highly disappointing. Apart from getting familiar with the reasons for placing patent diagrams in an application, it is vital to understand the basic patent diagram guidelines.
Guidelines for New Inventions & Prototypes
In general, diagrams are necessary for patent approval. The only time an applicant can do away with patent diagrams is when the invention relates to a chemical compound, or when claiming a composition, method, or process. Still, illustrations can help depict practically every method/process in one way, shape, or form. Therefore, it is wise for applicants to provide drawings even while claiming a method.
Moreover, all jurisdictions have specific guidelines that applicants must adhere to while creating diagrams for patent applications.
United States Patent and Trademark Office (USPTO) Rules:
- The paper used for patent diagrams must be white, matte in appearance (not shiny), and flexible yet robust. In addition, one can use only one side of the paper for writing or diagram. The paper size should be A4 (21cm x 29.7cm) or letter (21.6cm x 27.9cm).
- The margins for the paper should be uniform across the entire application: 2.5 cm from the top, 2.5 cm from the left side, 1.5 cm from the right side, and 1.0 cm from the bottom.
- The applicant should not use colors in technical writings submitted to the patent office. Patent offices allow color only when it is essential to convey details of the invention or prototype. For such exceptional circumstances, the applicant must submit a separate petition to the USPTO.
- A photograph is permitted only in instances where it is the only practical form of conveying the intricacies of an invention or prototype. One example would be a microscopic photo of chemical compounds. In such cases, applicants must convert these images into greyscales with specific DPI settings to enhance their overall quality, as they cannot be used in their original forms.
- Patent illustrators must accurately present all possible views to depict new inventions or prototypes. They can also include blown-up partial and exploded views of specific portions of the inventions. When using multiple viewpoints, they should arrange all diagrams to face a single direction on the paper.
- Professionals prefer vertical diagrams over horizontal ones; however, both can be used based on the requirements.
- The scale of the diagrams should be such that it should not appear crowded or congested when reproduced at 2/3rd of its submitted size. If a reduced-size diagram obscures details, the examiner may struggle to comprehend it and could reject it for revision.
- Shading & hatching are encouraged in depicting an invention and prototype if required.
- Although numbers are preferred as reference characters, both letters and numbers are allowed.
Types of Patent Diagrams
Now that we have familiarity with the USPTO’s basic requirements for patent diagrams for new inventions and prototypes, let us discuss the various types of patent diagrams in a patent application.
The three different types of patent diagrams found in patent applications are shown in Figure 2 below:
Figure 2: Three Different Types of Patent Diagrams
Utility Patent Diagrams
These diagrams are generally created to correspond to the claims and descriptions of the patent. A seasoned draftsperson produces utility patent diagrams that optimally depict the claim and describe the invention. Specific views are used to highlight the problem that the invention solves or a particular advantage it offers. They can also convey a new function or elaborate on how an embodiment executes that function. Prior art emphasizes contrast or differentiates the latest invention from the old one. Utility patent diagrams also show the improved new portion with sufficient old inventions to reflect the connection. The diagrams in the utility patent application illustrate the following:
- Line diagrams portraying the shape of objects
- Block diagrams
- Flow charts
- Electric circuits
- Chemical formulas, among others
An applicant can create these diagrams even before writing the original patent application. By preparing a detailed description of the sequence of the diagrams, they can save time. An example of a utility patent diagram is shown in Figure 3 below:
Figure 3: An Example of Utility Patent Diagram
Design Patent Diagrams
Diagrams in a design patent application encompass the complete visual disclosure of claims and descriptions. These diagrams are so professionally drafted that nothing related to the design patent is left for conjecture. Most countries across the globe follow similar guidelines for design patent diagrams. Applicants must create multiple black-and-white line art views to fully depict the invention. If line art cannot accurately capture the design, they may submit photographs. When photos are not allowed, they must provide black-and-white diagrams instead.
These diagrams help to explain the aesthetics and appearance of the invention. Shading of design patent diagrams is obvious to highlight the invention’s contour, shape, and material textures. Unlike utility patent diagrams, design patent diagrams do not contain reference numbers. Essentially, these diagrams focus on the ornamental design of a functional item. Some common examples are – furniture, jewelry, computer icons, beverage containers, etc. An example of a design patent diagram is shown in Figure 4 below:
Figure 4: An Example of Design Patent Diagram
Plant Patent Diagrams
Similar to a design patent diagram, there is no use of reference characters in plant patent diagrams. These diagrams can be in color or black and white. Color diagrams are quite common in plant patent applications. The color diagram could be either in the form of photographs or prepared in permanent watercolor. Figure 5 below shows an example of a plant patent diagram:
Figure 5: An Example of Plant Patent Diagram
Different angles are critical in fully conveying the invention and all its features and characteristics. The next section discusses various views used to illustrate the invention in patent diagrams.
Different Views in Patent Diagrams
Some of the commonly used views in patent diagrams are listed below:
Perspective View
This view is concerned with portraying a three-dimensional approach to the invention. The angle of the view demonstrates the height, width, and breadth for a more realistic approach. This view’s objective is to provide the best understanding of the shape and design of the invention. In contrast, an orthogonal view renders a two-dimensional representation of an invention. An example of a perspective view in patent diagrams is shown in Figure 6 below:
Figure 6: An Example of Perspective View in Patent Diagram (Source)
Orthogonal View
This view focuses on showing the invention with one side parallel to the diagram surface. The most common orthogonal views are front, rear, right, left, top, and bottom. Examples of orthogonal views are shown in Figure 7 below:
Figure 7: An Example of Orthogonal View in Patent Diagram (Source)
Sectional View
It becomes crucial to show the internal parts and components to explain the intricate details of an invention. The sectional views are taken alongside a plane that intersects the object or device. Figure 8.2 below offers a sectional view of the interlocked blocks from Figure 8.1, wherein, the number 5 is located at two places adjacent to arrows on opposite sides of the blocks. The arrows intersect a broken line that runs along the block length and show the plane along which the section is cut. The arrows demonstrate the direction in the sectional view.
In Figure 8.2, diagonal hatching lines mark the surface cut by the section plane, representing the section surface with solid fills. Sometimes, hatching lines of varying widths, such as thick and thin lines, help articulate the type of material used in the invention, as shown in Figure 8.2.
Figure 8: An Example of Sectional Views in Patent Diagram (Source)
Exploded View
Exploded view enables you to demonstrate the relationship and order of parts in an assembly. If projection lines do not trace the path of the parts, a bracket must indicate all components of the exploded assembly. For example, in Figure 9 below, the bracket at 10 shows that parts 42, 16, 12,60, 14, and 62 are all components of the invention. Although a few projection lines connect parts 18 and 20, they do not extend across the entire part. Therefore, a bracket is necessary.
Figure 9: An Example of Exploded View in Patent Diagram (Source)
Partial View
When required, a view of a large machine or device may be separated into partial views on one sheet or may be extended over several sheets. Views on multiple sheets should effectively form one complete view in such instances. Additionally, arrange views across multiple sheets so that the entire figure can be assembled without obscuring any part of the views on different sheets. An example of a partial view is shown in Figure 10 below:
Figure 10: An Example of Partial View in Patent Diagram
Irrespective of the views used in patent diagrams, hatching, and shading are crucial in establishing the differences between a part’s functioning and operation. The next section elucidates the same.
Relevance of Hatching & Shading Techniques in Patent Diagrams
Hatching and shading techniques are used to explain the parts’ material and surfaces and comprehend the related parts’ appearance. These techniques assist in differentiating the color as well as the forms of an invention’s parts.
Hatching is generally used to demonstrate the cross-sections or colors. Its primary aim is to produce a tonal effect by diagram parallel lines, oblique lines, dots, and different patterns. Although professionals use the hatching technique in both utility and design patent diagrams, they apply it more commonly in the former. In design patent diagrams, they use it primarily to illustrate texture. The following list highlights some common uses of hatching techniques:
Relevance in Utility Patent Diagrams
Hatching techniques are used here for showing cross-sectional views and denoting different colors. Figure 11 below illustrates an example of a hatching technique used to depict a cross-sectional view.
Figure 11: An Example of Cross-Section View Using Hatch Pattern
In Figure 11, the image on the left-hand side has no hatching. Consequently, the examiner may confuse its understanding as a cross-sectional view or the original shape of a complete part. The image on the right-hand side uses a hatch pattern to demonstrate a cross-sectional view.
Figure 12 below illustrates an example of a hatching technique used to highlight different colors
Figure 12: An Example of Hatching Technique to Illustrate Different Colors
The left-hand-side image in the Figure 12 uses multiple colors to explain the statistics. However, as per the laid-out rules, the diagram will invite rejection from the USPTO as colored diagrams are not permitted. The image on the right-hand side uses a hatch pattern to portray the statistics and the corresponding color. The second image is the correct approach for demonstrating a color graph in utility patent diagram.
Relevance in Design Patent Diagrams
Hatching is utilized to highlight the texture or the material of the product in design diagrams. Applicants can use various hatches to portray the fabric’s surface, such as leather or velcro. An example of the hatching technique in the design diagram is shown in Figure 13 below:
Figure 13: An Example of Hatching Technique to Show the Texture of a Bag
Shading visually defines an object and provides a clear understanding of its ornamental design. Professionals generally use this technique to highlight circular shapes, emphasize the depth of a part, create 3D effects in 2D designs, illustrate contours, etc. The correct shading in patent illustrations negates the probability of confusion and rejection by patent examiners. Illustrators commonly use two types of shading. These are:
Linear Shading
It is used to highlight surfaces in patent diagrams. The linear shading can be curved, flat, or tapered. The thickness or weight of the shading line must be less than the thick line of the product, which is the outermost line with more weight than any other line on the diagram. An example of linear shading is shown in Figure 14 below:
Figure 14: Different Types of Linear Shading in a Diagram
Stippled Shading
It means creating a pattern that simulates different levels of shading with the assistance of tiny dots. Stippling utilizes numerous dots/points to generate the impression of an object and its texture. It removes the negative space, making a surface look more textured, shadowy, and closer to the viewer.
Figure 15 below illustrates an example of stippled shading:
Figure 15: An Example of Stippled Shading in a Diagram
Despite being aware of the rules and techniques, there are still obstacles to overcome in drafting patent diagrams or drawings. The next section discusses the same.
Hurdles in Patent Diagrams or Drawings
The following section discusses some of the challenges involved in creating patent diagrams or illustrations:
- Inconsistency: One of the main challenges for inventors is the discrepancy between the claims and diagrams, which leads to rejection in many instances.
- Technical nature: Patent diagrams are usually very technical. Therefore, if it falls short of technical accuracy, it leads to rejection of the application, as a whole, when the diagram is compulsory to support the claim of novelty and non-obviousness. While drafting, one should keep in mind that illustration quality is more important than the quality of the tools.
- Cost: Applicants should be aware of different jurisdictions and specifications such as EPO, USPTO, and CNIPA, etc. Access to tools, such as ChemDraw (for chemical diagrams), AutoCAD, and Visio (for diagram flowcharts), increase the cost for the inventors. Subsequently, if the diagrams or patent applications are rejected, it disheartens them from incurring more expenses and applying again.
- Data as diagrams: Printouts of a lab report must be submitted as data to the patent office for chemical and biological experiments. As per the guidelines, it must be on an A4 size paper with a preference for black ink. The rule creates all kinds of problems because data need color coding and the use of color requires proper justification—lack of which can lead to application rejection.
Modern software can help produce faultless illustrations and eliminate several hurdles and challenges that occur in patent diagrams. Take a look at these in the next section.
Advanced Software to Create Error-Free Illustrations
- AutoCAD: Computer-aided design (CAD) software enables professionals to generate precise 2D and 3D diagrams, particularly in mechanical engineering and electrical design. Moreover, the software enables seamless modification of designs while leveraging a reusable block library to replicate design components. As a result, applicants can create highly accurate designs across all dimensions.
- SolidWorks: It is a computer-aided design and engineering program published by Dassault Systèmes. The software facilitates planning, visual ideation, modeling, feasibility assessment, prototyping, and project management. In addition, it finds utility in building and designing electrical, mechanical, and software elements.
- CorelDRAW: A vector graphics editor from Corel Corporation offers various tools to create original images or edit them. A few programs in the CorelDRAW Graphics Suite are Corel Capture, Corel PHOTO-PAINT, Corel Font Manager, CorelDRAW, and AfterShot 3 HDR. The software also finds practical application in designing brochures, flyers, design magazines, books, newspapers, logos, signage, and calendars.
- MS Visio: It is a program for vector graphics and diagrams under the Microsoft Office suite of products. The software can help create data flow diagrams, 3D maps, flowcharts, and much more. The program is similar to AutoCAD and CorelDRAW. Depending on requirements, it generates the diagrams in completely editable VST file format.
- Adobe Illustrator: Artists and graphic designers commonly use the software to produce scalable vector artwork for web and print. Visuals created in patent diagrams using Illustrator include shapes, icons, logos, and designs.
- OmniGraffle: It is a holistic yet straightforward diagram application. Its “Drag and Drop” feature enables applicants to produce rough diagrams for wireframes, user interface (UI) mock-ups, flowcharts, family trees, etc.
Even with the most advanced software, there can be errors, which lead to the addition of replacement and new sheets in patent diagrams. In the next section, we are going to discuss the same.
Understanding the Significance of Replacement & New Sheets in Patent Diagrams
A replacement sheet is used when the defective figures are replaced by modified ones. According to the U.S. Patent and Trademark Office (USPTO), all the replacement sheets of patent diagrams must adhere to § 1.84 and must include all the figures present in the original version of the sheet. The sheet added as a replacement for an old one must include the label “Replacement Sheet.” Below are some common issues that may require a replacement sheet.
- Use of colored images
- Incorrect text height
- Inconsistency of shadings or parts in design diagrams
Compared to a replacement sheet, a new sheet is added to an office action (OA) response when the diagrams are rejected due to lack of clarity. The reason can be the examiner’s inability to comprehend the diagrams, or visibility issues that make it difficult to grasp the depth, height, or shape of any part. Therefore, it is advisable to either disclaim the part or add a new sheet with the correct projection.
In a nutshell, applicants should add a “New Sheet” while adding new matter to the diagrams.
There are many reliable third-party service providers for producing error-free patent diagrams. However, PatSketch (formerly The Patent Drawings Company) has devised a unique approach to delivering impeccable patent diagrams for its clients across industries. In the next section, we will discuss why choosing PatSketch’s service proves beneficial.
Why Choose PatSketch for Utility and Patent Diagrams
- Reasonable pricing
- Unlimited iterations
- Delivery in multiple formats
- Expedited delivery
- Feedback incorporation within 24 hours
- Dedicated business manager for clients
- Illustrators available on-call
Final Thoughts
Patent diagrams are an indispensable part of patent applications. Faultless patent diagrams increase the probability of a timely grant of the patent application as they clearly explain the inventions’ novelty and uniqueness. However, it is advisable to learn about the types of patent diagrams, challenges, and rules to save time and avoid rejections. Many organizations undertake the task of drawing themselves. However, it is wise to avail of the services of a reliable third party specializing in the field.
At PatSketch (formerly The Patent Drawings Company), we set out on a mission to deliver next-generation patent drawing solutions for businesses across sectors. Today, professionals across the IP world and various industries recognize and trust our expertise. We create accurate illustrations that comply with the patent diagram rules of the relevant PTO. Our experienced team specializes in utility patent drawings services and design patent drawings services, ensuring your invention is presented in the best possible way.
