Introduction: The determination of design patent infringement is different from the determination of invention and utility model patent infringement, and there is relatively little theoretical research. There are many divergent or even opposite views and results in theory and practice.

The so-called appearance design refers to a new design that is aesthetically pleasing and suitable for industrial application of the shape, pattern, color, or their combination of a product. Due to substantial differences in content and legal requirements for granting patent rights between design patents and invention patents and utility model patents, there are many differences in the determination of infringement of design patents compared to invention patents and utility model patents. In actual evaluation, there are many controversies and even completely opposite conclusions.

1、 Conditions for the Establishment of Design Infringement

To determine that the accused infringing product has infringed a design patent, both of the following conditions must be met simultaneously.

(1)The accused infringing product must fall within the scope of protection of the design patent right

According to the Patent Law of our country, the scope of protection of a design patent right shall be based on the design patent product represented in the drawings or photographs. Therefore, to determine whether the accused infringing object is infringing, the first step is to determine the scope of protection of the design patent right.

1. The determination of the scope of protection of a design patent shall be based on the design represented in photographs or pictures.

The pictures, photographs, and related explanations submitted by the patentee to the patent administrative department of the State Council when applying for a patent are the only basis for determining the scope of protection of the design patent right. They are specifically reflected in the front view, top view, bottom view, left view, right view, rear view, etc. of the patented product in the design application, and if necessary, sectional views, sectional views, and state reference drawings, especially the aesthetically pleasing elements in the drawings. Due to the fact that design patents are aimed at ordinary consumers in society, based on their cognitive ability towards design, the scope of protection of design patent rights should not only include the same design, but should also include similar designs that are substantially similar to the patented product and difficult for ordinary consumers to distinguish.

2. The brief description of the appearance design accurately limits the scope of protection for the appearance design.

Article 28 of the Implementing Regulations of the Patent Law stipulates that when applying for a design patent, a brief description of the design shall be provided when necessary. The brief description of the appearance design should specify the design points of the product using the appearance design, the request for color protection, and the omission of views. A brief explanation should not use commercial promotional language, nor should it be used to describe the performance of the product. A brief description of the appearance design helps to accurately understand the scope of protection of the appearance design, but the explanation and limitation of the expansion or reduction of the scope of protection of the appearance design made by the brief description are invalid.
The design essence is the unique and completely new part of the design requested for protection by the design patent holder, which reflects the designer's unique wisdom in the design. The reason why a design can obtain patent rights is precisely because it has unique design elements that other designs do not have. When a design patent product has a brief description, the patentee has the obligation to submit the design key points of the design and explain the original parts and content that the design requires protection, in order to facilitate the judge's judgment when determining whether the design infringes the patent right. However, if the patentee has already submitted the design concept drawings to the Patent Office when applying for a design patent, then the patent file of the design concept drawings is evidence of the design concept drawings.
From a certain perspective, exterior design can be said to be a work of art that can be applied to a certain product, therefore, color plays an important role in exterior design. If the patentee requests protection of color in the brief description, then the requested protection of color should be considered as a factor limiting the scope of protection of the design patent. When making a judgment on infringement, one should not only consider the language description of color by the patentee. Language description of color is limited, and the patentee should also provide relevant color evidence certified by the patent office to determine the scope of color protection for the design. When there is a significant dispute between the two parties, it should be checked against the colors in the patent file.
The method of color comparison is to compare the shape, pattern, color, or combination of the design images provided by the applicant to the patent office with the shape, pattern, color, or combination of the accused infringing product one by one, rather than comparing the patented product with the infringing product. Because the patent law protects designs represented in photographs or pictures, and patented products in reality may have undergone changes, at least not complete restoration of the photographs or pictures. To avoid bias, the infringing product should be compared with the product in the photo or image.

3. Content that is not within the scope of design patent protection.

Because the design patent protects the decorative and aesthetic appearance of a useful item, rather than the carrier product on which the design exists, the carrier of the design - the material, function, size, technical characteristics, structural content, etc. related to the product itself are not within the scope of protection.
The design patent protects the appearance of a new design, which is a tangible thing, not a thought or viewpoint. Therefore, the designer's design concept, conceptual skills, technical solutions, and the meaning of the text in the product pattern are not within the scope of protection of the patent law.
A design patent is created by the designer's creative thinking, and the shape, color, and pattern determined solely by the product's function are reflections of the product's natural characteristics and do not fall within the scope of the designer's creative labor. Therefore, the shape, pattern, and color determined solely by the product's function should be excluded from the protection scope of the design patent right.
The novelty of a design requires that the design must not be a publicly known technology prior to the date of application or priority of the design patent, and the publicly known technology content in the design is not within the scope of protection. It should be emphasized that the commonly known content referred to in this article refers to the overall appearance design, not the parts and elements. If a design adds unique design points or innovative elements to a known design, exhibiting a unique and aesthetically pleasing new design that is different from the known design elements, it can still constitute a patent, and its unique design points or innovative parts are naturally within the protection scope of patent law.
There are different debates in theory and practice regarding whether new designs that are purely composed of known technological groups and are aesthetically pleasing and suitable for industrial applications can be patented. The author believes that a new design composed of several known technologies, if the applicant achieves an effect that cannot be achieved by a single known technology or other known technology combinations through unique and previously unseen combination methods, forming a new design that is aesthetically pleasing and suitable for industrial applications, and meets the requirements of novelty in appearance design, should be recognized as a patented product and protected by patent law in both theory and practice. Those who infringe upon such design patents should also bear responsibility.

（2） The infringing product and the carrier product of the design must belong to the same category

Article 56 of China's Patent Law stipulates that "the scope of protection of a design patent shall be based on the design patent product represented in the drawings or photographs." Therefore, the design protected by the Patent Law must exist on a determined product. If it is only a pattern, a drawing, or a combination thereof, but not used on a determined product, its design itself cannot constitute a design patent and belongs to the scope of copyright protection, which is not subject to the regulation of the Patent Law. The product referred to here must be the product specified by the applicant at the time of application. The product must have a name, and the product name used when applying for the appearance design is not related to the scope of protection of the product appearance design, but is related to determining whether the product belongs to the same category when judging the infringement of the appearance design.
The product is an inseparable part of the design, and new designs that are aesthetically pleasing and suitable for industrial applications are inseparable from their carrier products. If the accused infringing product is not of the same type as the design patent product, it does not constitute an infringement of the design patent right. The reason why there is such a substantial difference between the provisions on infringement determination of invention and utility model patents is that new designs that are aesthetically pleasing and suitable for industrial applications can only exhibit unique aesthetic effects when combined with specific products. Imagine applying a beautiful new design for a refrigerator to a carpet, the effect would definitely be far inferior.
In practice, it should be noted that design patent products are aimed at ordinary consumers. From the perspective of ordinary consumers, if the accused infringing product is similar in category, shape, purpose, and function to the design patent product, and produces the same aesthetic effect in the eyes of consumers, from a fair perspective, it should also be recognized as a similar product and can be compared for infringement. For the same reason, to determine whether it is a similar product, the product classification criteria should not be based solely on the International Classification of Designs, but should be based on the conventions and rules of classifying accused infringing products and design patent products. As long as two products belong to the same category or the same type according to consumer perception, infringement comparison can be made. The practice of strictly limiting the accused design infringing products to the same category as the design patent products based solely on the International Classification of Designs is theoretically not in line with the legislative intent of the Patent Law and is not conducive to the protection of design patent rights in practice.

2、 Rules and Methods for Judging Infringement of Design Designs

If the accused infringing product meets the above two conditions, theoretically it can be determined that the infringement behavior is established. However, more importantly, in the actual infringement evaluation, the evaluation rules and methods for the similarity or similarity between the accused infringing product and the design patent product are used.

（1） Determination of comparative objects in infringement assessment

According to the provisions of China's Patent Law on the scope of protection of design patents, which are based on the design patent product represented in pictures or photographs, the comparison object should be the comparison between the accused infringing product and the pictures or photographs submitted by the patentee to the State Council's patent administrative department and authorized by the announcement when applying for a patent. This completely excludes the possibility of comparing the actual patented product with the accused infringing product.
This regulation has its rationality. Firstly, the patentee or the actual producer of the patented product cannot guarantee that the patented product they produce is completely identical to the patented product in the picture or photograph. Sometimes, in order to pursue a more perfect effect, some modifications may be made to the design patent. Comparing the design patent products actually produced by the patentee or actual patent product manufacturer with the accused design infringing products increases the unscientific and inaccurate nature of patent infringement judgments.
Secondly, the basis for society's understanding of the scope of protection of design patents can only be the pictures or photographs of design patents announced by the patent administration department of the State Council to the society, as well as brief explanations when necessary. If the infringement judgment of design patents is based on the patent products actually produced by the patentee, it increases the burden on the public. The public not only needs to understand the scope of protection of design patents in the photos or pictures announced in the announcement, but also needs to pay attention to the scope of protection declared to society by the actual production of design patent products. This not only violates the provisions of the Patent Law, but also increases the extralegal obligations of the public, causing injustice to the public; On the other hand, it also leaves the public at a loss and unable to determine which product it is protecting, deviating from the purpose of patent legislation to protect patents through public declaration of patents.
Secondly, if the patent product actually produced by the patentee is compared with the accused infringing product, once the accused infringer claims that the actually produced patent product is inconsistent with the patent product in the photos or images in the announcement, the court will inevitably compare the actually produced product with the accused infringing product and make a judgment on the accused infringer's request. This not only deviates from the original purpose of the judgment, but also increases the waste of litigation resources. Based on the above analysis, in actual infringement assessment, it is absolutely prohibited to compare the accused design infringing product with the product actually produced based on the design patent, in order to ensure the fairness of legal enforcement and the accuracy of the judgment.

（2） Rules for Comparing Similarities or Similarities in Infringement Assessment

1. The similarity between the accused infringing product and the design patent product should be judged based on the level of knowledge of design patents among ordinary consumers in society. As mentioned in this article, the majority of the audience for design patent products are ordinary consumers in society. The technical level and aesthetic views of ordinary consumers are definitely not as good as those of design professionals. Infringement of design patent holders may sometimes go unnoticed in order to counterfeit patented products, and they often make subtle changes to the design patent products. These changes are generally not noticed by ordinary consumers in society, and they often mistake them for design patent products to purchase. However, experts or professional designers with professional experience can easily distinguish these subtle changes between the two. If the level of experts or professional designers in the field of design is used to determine whether the accused infringing product is the same or similar to the patented product, then those products that have undergone minor modifications to the design patent product, are not seen as the same or similar by professionals, and are mistaken by ordinary consumers as patented products, will not fall within the scope of protection of the design patent product. The design of the patent protection system will be meaningless, which is not only not conducive to protecting the legitimate rights and interests of the design patent owner, but also not conducive to protecting the interests of consumers.

2. Comprehensive observation and judgment.
It is easy to make a similarity judgment when the accused infringing product is identical to the design patent product. The similarity judgment is more prone to controversy.
The shape, color, and pattern that make up a design can be singular or combined. In most cases, a design is a combination of several factors. Due to the fact that the appearance design of a product is aesthetically pleasing through its overall effect, whether the appearance design is composed of a single or combined element, comparing whether the accused infringing product is similar to the design patent product should start from the overall appearance design and cannot be observed in isolation or in isolation. Through comprehensive observation, if the subtle differences between the accused infringing product and the patented product are not easily noticeable or do not affect the overall effect in the eyes of ordinary people, the two are similar products; If two exterior designs are only identical in a few individual elements, and the main constituent elements are not the same or similar, and there is a significant difference in overall effect that will not cause confusion for consumers, then they do not constitute similarity.
3. Visual observation cannot rely on scientific methods or instruments.
The aesthetic effect caused by appearance design is observed through human vision, not detected through scientific means or instruments. Therefore, when judging whether they are the same or similar, only the observation results of human eyes can be used as the basis. The differences detected through scientific methods or instruments do not conform to the essential characteristics of appearance design and cannot be used as the basis for evaluation.
4. Important part.
The so-called essential parts refer to the parts in some products that are easy to attract people's attention. The reason why a product is granted a patent is often because it creates a unique aesthetic that sets people apart from the past. It can be said that the key to obtaining patent rights is to obtain them. So, when comparing, the focus should be on the department.
5. Remove the publicly known design section.
This rule is a supplement to the rules of comprehensive observation and judgment. When the accused infringing product and the design patent product adopt the same or similar well-known design, from a holistic perspective, the two may give people the same or similar feeling. If we do not pay attention to observing and considering whether the design points or innovative parts of the two are substantially different, we may easily draw the same or similar conclusion, which may lead to erroneous judgments.
In the above situation, the reason why the patentee obtains a patent is not because of its publicly known parts, but rather because of the unique aesthetic appeal of its design points or innovative parts. Therefore, when comparing, the first step is to eliminate the common or similar parts of the two, and distinguish the improved parts between the two. At this stage, the burden of proof for the accused infringer and the patentee is different. The accused infringer should provide evidence to prove that the design belongs to the public domain, while the patentee should prove which parts are their original and aesthetically pleasing improvements.
By comparing the two, if the improved parts of the accused infringing product are the same or similar to those of the patented product, the infringement is established; If the accused infringing product does not include the improved part of the patented product or its improved part is different or dissimilar from the improved part of the patented product, it does not constitute infringement.
By understanding the conditions and evaluation criteria for design infringement, one can determine whether their design patent has been infringed and take timely protective measures; On the other hand, when developing and producing new products, enterprises should organize technical personnel to cooperate with patent legal personnel to conduct patent analysis and determine whether the product is the same or similar to a product that has already obtained a design patent.