The difference between the "termination date due to expenses" of many patents and the patent authorization date is less than 2 years.

"The annual fee for granting the patent right shall be paid at the same time as the registration formalities, and the subsequent annual fee shall be paid in advance within one month before the expiration of the previous year. If the patentee fails to pay the annual fee on time (excluding the annual fee in the year when the patent right was granted) or the amount paid is insufficient, it may be paid within six months from the date of expiration of the annual fee. "

So the patent fee is paid once a year, so the so-called validity period is also one year.

There are many reasons for the patentee to terminate the patent, mostly because of economic reasons that the economic value of continuing protection is not great. The patentee may stop paying the patent fee and terminate his patent, or voluntarily give up his patent and make a written statement.

Supplement: The term of invention patent is 20 years, and the term of utility model patent is 10 years, provided that the annual fee is paid and there are no other invalidation declarations. However, if the annual fee is not paid, the patent may be invalid.