A design patent protects only a product's "external appearance," while an invention patent and a petty patent protect its "mechanism or how it works." The two groups protect different aspects of the same product, so in some cases you can seek both protections at once. If your product has both a new appearance and a new mechanism worth protecting, consider filing both types as separate applications.
What a Design Patent Protects
A design patent under Thailand's Patent Act B.E. 2522 protects the shape, form, or pattern of a product visible from the outside, including the arrangement of color elements on the product's surface - not how the product works or what it does. It's protected for 10 years from the filing date, cannot be renewed, and shapes dictated purely by functional necessity don't qualify (see What Is a Design Patent? for more detail).
What an Invention Patent and Petty Patent Protect
An invention patent and a petty patent protect an invention's "mechanism, structure, or process" - not its appearance. The two differ in examination standard and protection term:
- Invention patent - must satisfy 3 requirements: novelty, an inventive step, and industrial applicability. Undergoes substantive examination. Protected for 20 years from the filing date, cannot be renewed, but requires annual fees starting from year 5 to keep the patent in force.
- Petty patent - drops the inventive-step requirement entirely, leaving only novelty and industrial applicability. Undergoes only a preliminary examination, so it's granted faster. Initial term of 6 years, renewable twice for 2 years each, for a maximum of 10 years from the filing date.
Both suit inventions with technical novelty - unlike a design patent, which looks only at whether the appearance is new.
Comparison at a Glance
| Type | What It Protects | Protection Term |
|---|---|---|
| Design Patent | External appearance | 10 years, not renewable |
| Invention Patent | Mechanism/function (with an inventive step) | 20 years, not renewable (annual fees apply) |
| Petty Patent | Mechanism/function (no inventive step required) | 6 years, renewable up to 10 years |
Can You Hold Both Protections at Once?
In principle, yes - a design patent and an invention/petty patent are different types of patent rights that protect different aspects of the same product. The law does not prohibit seeking both protections at the same time, but they must be filed as separate applications. Examples of products that may benefit from both:
- Appliances or electronic devices - the internal mechanism is protected by an invention or petty patent, while the specifically designed housing shape is protected by a design patent
- Furniture with a special adjustment mechanism - the reclining or folding mechanism goes to an invention/petty patent, the external form to a design patent
- Packaging with a specific dispensing mechanism - the dispensing or sealing mechanism goes to an invention/petty patent, the bottle or box shape to a design patent
Which Should You File First on a Limited Budget?
Consider your product's main selling point. If its strength is a "look" that makes it stand out on the shelf or in the market, prioritize the design patent - a competitor who copies the mechanism but changes the appearance won't be caught by a design patent anyway. If its strength is a "new mechanism or function" that a competitor could copy while giving it a different look and still have it work the same way, prioritize the invention patent or petty patent. For a product where both appearance and mechanism are equally important selling points, and budget allows, consult a patent agent to plan filing both from the start - filing later can forfeit rights, since novelty for both types is assessed as of the filing date.
Frequently Asked Questions
If I only hold a design patent and a competitor copies the mechanism but changes the appearance, can I sue?
Not for design patent infringement - a design patent protects only the specific external appearance you registered, not the mechanism or how the product works. To protect the mechanism as well, you need to file for an invention patent or petty patent separately from the start.
If I file both a design patent and a petty patent for the same product, do I need to file them as separate applications?
Yes, they must be filed as separate applications, because they are different patent right types under the Patent Act B.E. 2522. Each has its own application form, examination process, and fees, even when filed for the same product around the same time.
