Abstract: An improved ink tube structure is disclosed. The improved ink tube structure of the present invention comprises a hollow ink tube and a writing tip. A first bent portion is disposed near the writing tip on the hollow ink tube so that a bent angle is formed at the first bent portion and a distance between the curvature center of the first bent portion and the end point of the writing tip is formed. In this way, an ergonomic design may be provided. A second bent portion may be disposed behind the first bent portion on the hollow ink tube. To keep the first bent portion from deforming, a retaining device is disposed at the first bent portion. A groove is provided on the retaining device so as to hold the first bent portion and keep the first bent portion from deforming.

Abstract: A offset pen includes a holding part, a writing end and a connecting part connected therebetween, in which the writing end and the holding part are disposed on different axes. When the user is operating the writing tool, the holding part inclines naturally while the writing end keeps vertical to the writing surface, and the writing result can be observed through the visible space formed between the writing end and the holding part. A holding end is disposed at the front end of the holding part of the writing tool, and each surface of the holding end can be twisted into irregular surfaces. Since the holding part, the connecting part and the writing end are substantially arranged as a Z letter, a perfect fitting feeling of the fingers can be created. Therefore, different users can feel comfortable and the fingers of the users with different holding poses can be naturally directed to a correct holding position, so as to form various geometric states suitable for hand holding.

Abstract: A offset pen includes a holding part, a writing end and a connecting part connected therebetween, in which the writing end and the holding part are disposed on different axes. When the user is operating the writing tool, the holding part inclines naturally while the writing end keeps vertical to the writing surface, and the writing result can be observed through the visible space formed between the writing end and the holding part. A holding end is disposed at the front end of the holding part of the writing tool, and each surface of the holding end can be twisted into irregular surfaces. Since the holding part, the connecting part and the writing end are substantially arranged as a Z letter, a perfect fitting feeling of the fingers can be created. Therefore, different users can feel comfortable and the fingers of the users with different holding poses can be naturally directed to a correct holding position, so as to form various geometric states suitable for hand holding.