Patent drawings

35 U.S.C. 113 says the applicant shall furnish a drawing where necessary for the understanding of the subject matter sought to be patented. Where the subject matter admits of illustration by a drawing and the applicant has not furnished one, the Director may require it within a time period of not less than two months from the sending of a notice¹. 37 CFR 1.81(c) puts the same rule in terms of the examiner, who will require the drawing².

There is a firm limit on drawings added later. Drawings submitted after the filing date may not be used to overcome an insufficiency of the specification due to lack of an enabling disclosure or otherwise inadequate disclosure, or to supplement the original disclosure for the purpose of interpreting the scope of any claim (35 U.S.C. 113; 37 CFR 1.81(d))^1,2. The figures therefore need to be right at filing. See Patent disclosure.

For content, 37 CFR 1.83(a) says the drawing in a nonprovisional application must show every feature of the invention specified in the claims. Conventional features whose detailed illustration is not essential should be shown as a graphical drawing symbol or a labeled representation, such as a labeled rectangular box. Tables in the specification and sequences in sequence listings should not be duplicated in the drawings³. Where the invention improves an old machine, the drawing must when possible show the improved portion itself, disconnected from the old structure, and in another view enough of the old structure to show the connection (37 CFR 1.83(b))³. If the drawings do not comply, the examiner shall require additional illustration within not less than two months (37 CFR 1.83(c))³. See Patent claim.

37 CFR 1.84 sets the general standards for drawings. The table summarizes the main points. Read the rule itself for the full text, because it contains further detail and exceptions⁴.

The MPEP says drawings in utility and plant applications are reviewed by the Office of Patent Application Processing (OPAP) for compliance with certain requirements of 37 CFR 1.84. If the drawings are unacceptable for purposes of publication, OPAP sends a Notice to File Corrected Application Papers giving two months, extendable under 37 CFR 1.136(a). OPAP will not release the application to the Technology Centers until acceptable drawings are filed⁵.

• Under 37 CFR 1.85(a), a utility or plant application will not be placed on the files for examination until objections to the drawings have been corrected. Unless the applicant is otherwise notified in an Office action, objections to the drawings in a utility or plant application are not held in abeyance⁵.
• If drawings were indicated by the applicant as informal but OPAP considers them acceptable, the examiner should not require replacement. If the examiner does object to the drawings, correction is required in reply to the Office action⁵.
• If a drawing is not timely received in reply to a notice from the Office or a letter from an examiner requiring one, the application becomes abandoned for failure to reply⁵.
• Changes to drawings after filing are made on a replacement sheet labeled 'Replacement Sheet' that includes all figures of the prior version of that sheet, even if only one is amended. A sheet with an additional figure is labeled 'New Sheet', and the changes must be explained (37 CFR 1.121(d))⁵.
• For an allowable application needing corrected drawings, extensions of time to provide acceptable drawings in response to a notice of allowability are not permitted⁵.

These are USPTO procedures as stated in the MPEP edition cited under Sources. See Office action for how objections arrive during examination.

In a design application the drawing carries the claim. 37 CFR 1.152 says the design must be represented by a drawing that complies with 37 CFR 1.84 and must contain a sufficient number of views to constitute a complete disclosure of the appearance of the design⁷. The MPEP states that every design patent application must include either a drawing or a photograph of the claimed design, and that nothing about the design should be left to conjecture⁸.

• Surface shading should be used to show the character or contour of the surfaces. Solid black surface shading is not permitted except to represent the color black as well as color contrast⁷.
• Broken lines may show visible environmental structure but may not show hidden planes and surfaces that cannot be seen through opaque materials. Alternate positions of a design component shown by full and broken lines in the same view are not permitted⁷.
• Photographs and ink drawings may not be combined as formal drawings in one application, and photographs must be limited to the design claimed for the article, without environmental structure⁷.
• Color drawings are permitted in design applications under 37 CFR 1.84(a)(2), which also requires the specification to contain a reference to the color drawings⁴.

See Design patent for what a design patent protects.