1. The patent applied for first is different from the patent applied for later: if the patent applied for first is quite different from the patent applied for later in terms of technical scheme, innovation and practical application, the patent applied for later may be authorized.
2. The patent applied for first does not meet the conditions of patent authorization: patent authorization needs to meet many conditions, such as innovation, practicability and feasibility of technical scheme. If the patent applied first does not meet these conditions, the patent applied later can be granted.
3. The later applied patent provides a new technical scheme or improvement: If the later applied patent provides a new and better technical scheme or improvement, then Patent examiners may think that these schemes are more practical and innovative, thus authorizing the later applied patent.