Abstract: A headset device includes a headset body, a connection unit to move relative to the headset body, and a sensor unit having a light emitting element and a light receiving element to sense a biosignal, the sensor unit mounted to the connection unit to make contact with a human body. The sensor unit may measure a biosignal of a user, and the headset body and the sensor unit are indirectly connected by the connection unit. Accordingly, the sensor unit may be isolated from movement or vibration received through the headset body.

Abstract: A retractile mechanism for refills of writing instrument includes an outer tube, a refill, an inner tube, a sliding ring with load and a compression spring. The inner tube having a front stopper on the front end and a rear stopper on the rear end thereof. By movement of the sliding ring and the elastic rear stopper, the inner tube and the refill are pushed forward and backward so as to manipulate the refills of the writing instrument.

Abstract: A retractile pen includes an outer barrel and an inner barrel axially slidably received in the outer barrel. The outer barrel is provided with two axially spaced and aligned stop holes and the inner barrel is provided with an elastically depressible button adapted to partially project from either of the stop holes. By engaging the button on the inner barrel with a different stop hole on the outer barrel, the pen can be adjusted to either a longer length to facilitate writing with the pen or a shorter length to facilitate convenient carrying of the pen.

Abstract: A retractable "ball-pen" like tool/scalpel, provided with a latch mechanism, is automatically retracted when not in use by pushing the latch mechanism and is extended when in use by pushing a tool/blade support member of the tool/scalpel. The latch mechanism is engaged with the tool/blade support member when the tool/blade support member is pushed to an operative position wherein a tool/blade is exposed from a sheath member. The latch mechanism is pushed transversely and disengaged with the tool/blade support member whereby the tool/scalpel is retracted into the sheath member.

Abstract: A ball-point pen is disclosed, having a push button which can be displaced to a limited extent in longitudinal direction of the ball-point pen housing so as to extend the cartridge which is urged by spring in the inward direction, and having a detent means for locking the inwardly-pushed position of the push button. In order to obtain a simple structural form as well as a mechanism which operates trouble-free, it is proposed that the push button be developed as a slide plate and have on its wide side a tongue cut therefrom which extends resiliently transversely out of the wide side and bears the detent tooth of the detent means.