A ballpoint pen wherein an outer member (50) covering the outer circumference of a holder (21) covers a section that reaches as far as a narrowed section (23) of the holder (21) and has an outer member tip end portion (51). An ink spreads between the writing ball (30) and the contact section of the writing surface and between the outer member tip end portion (51) and the contact section of the writing surface, in which the writing ball (30) and the outer member tip end portion (51) are in contact with the writing surface at the same time. The relative position of the outer member (50) and the holder (21) can be changed from a holder protruding position to a holder retracted position wherein the writing ball (30) and the tip section of the outer member (50) can be in contact with the writing surface at the same time.

Provided are: a ballpoint pen with which the amount of bending of the pen tip can be changed, wobbling does not occur, and a stable writing feel can be obtained; and a ballpoint pen with which, to make it possible to clearly change the thickness of the drawn line by the force applied when writing, lines of different thickness can be written with a single writing tip using the angle of the ballpoint pen tip. The ballpoint pen is provided with: a writing ball; a holder for holding the writing ball by means of a swaged section the tip of which has been swaged; an ink supply section for supplying ink to the holder; a shaft body inside which the ink supply section is held; and a tip shaft, which is connected to the tip of the shaft body and from which the holder protrudes during writing.

Provided are: a ballpoint pen with which the amount of bending of the pen tip can be changed, wobbling does not occur, and a stable writing feel can be obtained; and a ballpoint pen with which, to make it possible to clearly change the thickness of the drawn line by the force applied when writing, lines of different thickness can be written with a single writing tip using the angle of the ballpoint pen tip. The ballpoint pen is provided with: a writing ball; a holder for holding the writing ball by means of a swaged section the tip of which has been swaged; an ink supply section for supplying ink to the holder; a shaft body inside which the ink supply section is held; and a tip shaft, which is connected to the tip of the shaft body and from which the holder protrudes during writing.

A ballpoint pen 10 includes: a ballpoint pen tip 20 having a writing ball 30 and a holder 21 holding the writing ball 30; a shaft tube 12 to which the rear end part of the ballpoint pen tip 20 is mounted; and ink 40 accommodated in the shaft tube 12. The holder 21 has an ink guiding hole 26 formed from the rear end thereof toward the head end thereof and a ball house 22 formed with the inner circumference near the head end of the holder 21 expanded. The writing ball 30 is formed of a zirconia sintered body with the content of an aluminum element being less than 0.1 weight %, and the ink 40 contains inorganic particles 41.

A writing tip assembly for dispensing a free-flowing low-viscosity ink from a writing instrument may include a micro-spring, a writing ball configured to transfer ink to a substrate, and a second ball between the writing ball and the micro-spring. The second ball is configured to transfer ink to the writing ball. A writing instrument for dispensing a free-flowing low-viscosity ink includes an ink reservoir, the writing tip assembly, and a feeder fluidically coupling the ink reservoir to the writing tip assembly.

A writing tip assembly for dispensing a free-flowing low-viscosity ink from a writing instrument may include a micro-spring, a writing ball configured to transfer ink to a substrate, and a second ball between the writing ball and the micro-spring. The second ball is configured to transfer ink to the writing ball. A writing instrument for dispensing a free-flowing low-viscosity ink includes an ink reservoir, the writing tip assembly, and a feeder fluidically coupling the ink reservoir to the writing tip assembly.

A writing tip assembly for dispensing a free-flowing low-viscosity ink from a writing instrument may include a micro-spring, a writing ball configured to transfer ink to a substrate, and a second ball between the writing ball and the micro-spring. The second ball is configured to transfer ink to the writing ball. A writing instrument for dispensing a free-flowing low-viscosity ink includes an ink reservoir, the writing tip assembly, and a feeder fluidically coupling the ink reservoir to the writing tip assembly.

A writing tip assembly for dispensing a free-flowing low-viscosity ink from a writing instrument may include a micro-spring, a writing ball configured to transfer ink to a substrate, and a second ball between the writing ball and the micro-spring. The second ball is configured to transfer ink to the writing ball. A writing instrument for dispensing a free-flowing low-viscosity ink includes an ink reservoir, the writing tip assembly, and a feeder fluidically coupling the ink reservoir to the writing tip assembly.

The retractable container of the present invention includes a body which accommodates a receptor supported by a spring and a knob configured to deploy and retract the receptor. In the retractable container, the body accommodates the receptor and the spring therein, has an entrance formed on one side thereof and an insertion opening formed on the other side thereof, into which the receptor and the knob are inserted, and comprises a body cam integrally formed with the body and comprising a guide bar which extends from the body to be disposed adjacent to a side of the insertion opening, and the knob is configured to have a feature in which a knock operation part is formed integrally with a protrusion member which connects an extension part and a pressing part inserted into the insertion opening of the body, thus the guide bar of the body cam is moved to respond to a change in position of the knock operation part.