PCT (Patent Cooperation Treaty) is an international treaty designed to simplify the procedure of patent application in multiple countries.  Under the PCT, applicants can seek patent protection in multiple countries through filing one international application, which help to save efforts and costs.  Consequently, PCT route increasingly becomes the preferred route for applicants to seek patent protection.

The PCT application can be divided into the international phase and the national phase.  When filing a PCT international application, if the application involves drawings or sequence listings, they shall be submitted in addition to the PCT request, description, claims, and abstract.  The article focuses on the common issues of drawings in the PCT international phase, including ways to modify drawings and the requirements of modifying drawings when filing applications with the China Receiving Office.

I. Common Issues of Drawings

According to the Regulations under the PCT (hereinafter referred to as "Regulations"), drawings, as part of the patent application documents, shall meet certain requirements.  Here are some common requirements for drawings.

1. Lines and Colors of Drawings

Rule 11.13(a) of the Regulations: Drawings shall be executed in durable, black, sufficiently dense and dark, uniformly thick and well-defined, lines and strokes without colorings.

Based on this provision, the followings can be deduced:

(1) It shall be avoided to use colored lines or elements in Drawings.

Currently, if the PCT international application is submitted in a non-XML format, the International Bureau will convert the application documents into XML format before publication.  Therefore, if the drawings in the application contain colored elements, the colored elements will be converted to black-and-white during the XML conversion process, potentially losing some content shown in the colored elements.

Here are two sets of examples:

Figure 1 is a drawing originally filed, with some red broken lines; Figure 2 is the published drawing thereof, where colored lines are lost.

Figure 3 is a drawing originally filed, including parts filled in blue and yellow; Figure 4 is the published drawing thereof, in which the colors are lost, and the parts filled in yellow or blue are changed into black-and-white parts.

Therefore, to ensure the completeness and accuracy of the drawing after publication, the applicant shall adopt black-and-white drawings.

(2) Lines in Drawings shall be sufficiently dense and dark, uniformly thick.

If the lines in the drawings are not uniform in thickness or insufficiently dense, some details may be lost during the XML conversion process, which will affect the accuracy of drawings in international publication.

For example, figure 5 is a drawing originally filed, where line A is thinner compared to other lines; Figure 6 is the published drawing thereof, in which the mentioned line is lost.

2. Requirements about Clarity and Scale

Rule 11.13(c) of the Regulations: 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.

Based on this provision, it can be deduced that if the clarity of the drawing is insufficient, or the image becomes blurred when reduced, details may become unrecognizable, which will affect the accuracy of drawings in international publication.

For example, figure 7 is the proposed submission drawing, with some fonts having low clarity, and the fonts become even more blurred when enlarged.

To avoid this issue, the applicant shall ensure that the submitted drawings maintain clear details during any reduction or enlargement process.

3. Specification for Letters and Numbers

Rule 11.13(h) of the Regulations: 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.

Based on this provision, it can be deduced that letters and numbers in the drawings should be clear and legible.  The applicant shall avoid using too small characters to ensure the contents remain readable when reduced or copied.

For example, figure 8 contains too small characters in the red frame, which become illegible when reduced.

4. Requirements about Language

Rule 26.3(a) of the Regulations: (a) Where the abstract or any text matter of the drawings is filed in a language which is different from the language of the description and the claims, the receiving Office shall, unless

(i) a translation of the international application is required under Rule 12.3(a) into the language in which the international application is to be published, or

(ii) the abstract or the text matter of the drawings is in the language in which the international application is to be published,

invite the applicant to furnish a translation of the abstract or the text matter of the drawings into the language in which the international application is to be published. Rules 26.1, 26.2, 26.3, 26.3bis, 26.5 and 29.1 shall apply mutatis mutandis.

According to the regulations, the text in the drawings or photographs in the application shall use the language in the international publication.  If the text in the drawings or photographs is in another language, it may incur relevant office action.

As shown in figure 9, the application was submitted in Chinese, but the drawings contain submitted another language, that is English.

II. Ways to Correct Drawings

Generally, the applicant could correct the defects in the application documents in the following two ways:

1. Responding to Office Actions

If the drawings do not comply with the Regulations under the PCT, the Receiving Office will issue a "Notice to Correct Defects in the International Application" (Form PCT/RO/106), indicating the defects and informing the applicant to amend within a specified period.  At this time, the applicant could contact the Receiving Office to obtain more detailed guidance and suggestions for correction.  The applicant shall make amendments to the drawings to overcome the defects indicated in the Notice and then submit the corrected drawings.

2. Making Voluntary Amendments

During the international phase, the applicant could make voluntary amendments. Even without receiving relevant notices, the applicant could voluntarily correct parts of the drawings that may not comply with the Regulations, such as submitting a clearer set of drawings.  Voluntary amendments do not mean that modifications are mandatory.  It provides an opportunity for the applicant to improve the application documents.

III. Requirements of Correcting Drawings

When resubmitting the corrected drawings, the applicant should pay attention to the following points:

1. Overcoming Identified Defects and Avoiding New Risks

If the amended drawings still do not overcome the defects indicated in the notice or if there are new defects that do not comply with the Regulations, the Receiving Office will issue new notice of correction, which will delay the examination procedure and increase the workload of the applicant.

2. Limitations on the Scope of Amendments

Regardless of the correction method, the amendments after filing stage cannot go beyond the protection scope of the originally filed documents.  The applicant shall ensure that the amendments only involve necessary formal corrections and avoid introducing new technical features or innovative points.

IV. Conclusion

In the international phase of a PCT application, it is crucial to submit drawings that meet the requirements and are of high quality.  In such case, the international application will be published correctly and accurately.  The accuracy of the international publication text will further affect the entry into national phase in different countries.  Drawings that comply with the regulations not only help examiners accurately understand the contents of the invention but also speed up the examination procedure.

The applicant should strictly adhere to the relevant provisions of the PCT and the Regulations thereof to ensure the quality of the drawings to avoid delays in the examination procedure due to formal defects.  At the same time, for any corrections required, the applicant should respond in time and make corrections as required to ensure the smooth prosecution of the patent application.

This article aims to help applicants clearly understand the regulations and common issues regarding drawings in PCT international applications, effectively reducing extensions caused by repeated amendments.  Hope the above information is beneficial to protect applicants’ inventions and creations.