US Patent 10061406 Position pointer

A position pointer has a tubular housing having a first opening portion at one longitudinal end. A rod-shaped core body is arranged in the housing with a first end of the core body opposed to the first opening portion. A writing pressure detection circuit is arranged in the housing, which, in operation, detects a writing pressure based on movement of the core body. A signal transmitter is arranged in the housing, which, in operation, transmits a signal. The position pointer includes an elastic block of material sized and shaped to form a seal with an inner surface of the housing and positioned near the first end of the core body.