PCT Article 7
- (1) Subject to the provisions of paragraph (2)(ii), drawings shall be required when they are necessary for the understanding of the invention.
- (2) Where, without being necessary for the understanding of the invention, the nature of the invention admits of illustration by drawings:
- (i) the applicant may include such drawings in the international application when filed.
- (ii) any designated Office may require that the applicant file such drawings with it within the prescribed time limit.
PCT Rule 7
7.1 Flow Sheets and Diagrams
Flow sheets and diagrams are considered drawings.
7.2 Time Limit
The time limit referred to in Article 7(2)(ii) shall be reasonable under the circumstances of the case and shall, in no case, be shorter than two months from the date of the written invitation requiring the filing of drawings or additional drawings under the said provision.
PCT Rule 11
Physical Requirements of the International Application
11.5 Size of Sheets
The size of the sheets shall be A4 (29.7 cm x 21 cm). However, any receiving Office may accept international applications on sheets of other sizes provided that the record copy, as transmitted to the International Bureau, and, if the competent International Searching Authority so desires, the search copy, shall be of A4 size.
- (c) On sheets containing drawings, the surface usable shall not exceed 26.2 cm x 17.0 cm. The sheets shall not contain frames around the usable or used surface. The minimum margins shall be as follows:
- – top: 2.5 cm
- – left side: 2.5 cm
- – right side: 1.5 cm
- – bottom: 1.0 cm
11.11 Words in Drawings
(a) The drawings shall not contain text matter, except a single word or words, when absolutely indispensable, such as “water,” “steam,” “open,” “closed,” “section on AB,” and, in the case of electric circuits and block schematic or flow sheet diagrams, a few short catchwords indispensable for understanding.
(b) Any words used shall be so placed that, if translated, they may be pasted over without interfering with any lines of the drawings.
11.13 Special Requirements for Drawings
- (a) Drawings shall be executed in durable, black, sufficiently dense and dark, uniformly thick and well-defined, lines and strokes without colorings.
- (b) Cross-sections shall be indicated by oblique hatching which should not impede the clear reading of the reference signs and leading lines.
- (c) The scale of the drawings and the distinctness of their graphical execution shall be such that a photographic reproduction with a linear reduction in size to two-thirds would enable all details to be distinguished without difficulty.
- (d) When, in exceptional cases, the scale is given on a drawing, it shall be represented graphically.
- (e) All numbers, letters and reference lines, appearing on the drawings, shall be simple and clear. Brackets, circles or inverted commas shall not be used in association with numbers and letters.
- (f) All lines in the drawings shall, ordinarily, be drawn with the aid of drafting instruments.
- (g) Each element of each figure shall be in proper proportion to each of the other elements in the figure, except where the use of a different proportion is indispensable for the clarity of the figure.
- (h) The height of the numbers and letters shall not be less than 0.32 cm. For the lettering of drawings, the Latin and, where customary, the Greek alphabets shall be used.
- (i) The same sheet of drawings may contain several figures. Where figures on two or more sheets form in effect a single complete figure, the figures on the several sheets shall be so arranged that the complete figure can be assembled without concealing any part of any of the figures appearing on the various sheets.
- (j) The different figures shall be arranged on a sheet or sheets without wasting space, preferably in an upright position, clearly separated from one another. Where the figures are not arranged in an upright position, they shall be presented sideways with the top of the figures at the left side of the sheet.
- (k) The different figures shall be numbered in Arabic numerals consecutively and independently of the numbering of the sheets.
- (l) Reference signs not mentioned in the description shall not appear in the drawings, and vice versa.
- (m) The same features, when denoted by reference signs, shall, throughout the international application, be denoted by the same signs.
- (n) If the drawings contain a large number of reference signs, it is strongly recommended to attach a separate sheet listing all reference signs and the features denoted by them.
37 CFR 1.437 The drawings.
The international application must contain drawings when they are necessary for the understanding of the invention. Moreover where, without drawings being actually necessary for the understanding of the invention, its nature admits of illustration by drawings, the applicant may include such drawings and any designated Office may require the applicant to file such drawings during the national phase. Flow sheets and diagrams are considered drawings.
Drawings must be presented on one or more separate sheets. They may not be included in the description, the claims or the abstract. They may not contain text matter, except a single word or words when absolutely indispensable. Note that if the drawings contain text matter not in English but in a language accepted under PCT Rule 12.1(a) by the International Bureau as a Receiving Office, the international application will be transmitted to the International Bureau for processing in its capacity as a Receiving Office. See 37 CFR 1.412(c)(6)(ii). If the drawings contain text matter not in a language accepted under PCT Rule 12.1(a) by the International Bureau as a Receiving Office, the application will be denied an international filing date.
All lines in the drawings must, ordinarily, be drawn with the aid of a drafting instrument and must be executed in black, uniformly thick and well-defined lines. Color drawings are not acceptable. PCT Rules 11.10 to 11.13 contain detailed requirements as to further physical requirements of drawings. Drawings newly executed according to national standards may not be required during the national phase if the drawings filed with the international application comply with PCT Rule 11. The examiner may require new drawings where the drawings which were accepted during the international phase did not comply with PCT Rule 11. A file reference may be indicated in the upper left corner on each sheet of the drawings.
All of the figures constituting the drawings must be grouped together on a sheet or sheets without waste of space, preferably in an upright position and clearly separated from each other. Where the drawings cannot be presented satisfactorily in an upright position, they may be placed sideways, with the tops of the drawings on the left-hand side of the sheet.
The usable surface of sheets (which must be of A4 size) must not exceed 26.2 cm x 17.0 cm. The sheets must not contain frames around the usable surface. The minimum margins which must be observed are: top and left side: 2.5 cm; right side: 1.5 cm; bottom: 1.0 cm.
All sheets of drawings must be numbered in the center of either the top or the bottom of each sheet but not in the margin in numbers larger than those used as reference signs in order to avoid confusion with the latter. For drawings, a separate series of page numbers is to be used. The number of each sheet of the drawings must consist of two Arabic numerals separated by an oblique stroke, the first being the sheet number and the second being the total number of sheets of drawings. For example, “2/5” would be used for the second sheet of drawings where there are five in all.
Different figures on the sheets of drawings must be numbered in Arabic numerals consecutively and independently of the numbering of the sheets and, if possible, in the order in which they appear. This numbering should be preceded by the expression “Fig.”
In situations where one or more sheets are added, each sheet shall be identified by the number of the preceding sheet followed by a slant and then by another Arabic numeral such that the additional sheets are numbered consecutively, starting always with number one for the first sheet added after an unchanged sheet (e.g., 10/1, 15/1, 15/2, 15/3, etc.). See Administrative Instructions Section 311.
The PCT makes no provision for photographs. Nevertheless, they are allowed by the International Bureau where it is impossible to present in a drawing what is to be shown (for instance, crystalline structures). Where, exceptionally, photographs are submitted, they must be on sheets of A4 size, they must be black and white, and they must respect the minimum margins and admit of direct reproduction. Color photographs are not accepted.
The procedure for rectification of obvious mistakes in the drawings is explained in MPEP § 1836. The omission of an entire sheet of drawings cannot be rectified without affecting the international filing date, except in applications filed on or after April 1, 2007, where, if the application, on its initial receipt date, contained a priority claim and a proper incorporation by reference statement, the original international filing date may be retained if the submitted correction was completely contained in the earlier application. See PCT Rules 4.18 and 20.6. Rectifications of obvious mistakes are not considered to be amendments.
The drawings can be amended during the international phase only if the applicant files a Demand for international preliminary examination. The drawings can also be amended during the national phase. The amendment shall not go beyond the disclosure in the international application as filed. See PCT Article 34(2)(b).
If drawings are referred to in an international application and are not found in the search copy file, the examiner should refer the application to a Quality Assurance Specialist in his or her Technology Center or a PCT Special Program Examiner. See Administrative Instructions Section 310.