Position pointer

1. A position pointer, comprising:

a tubular housing having a first opening portion at one longitudinal end;

a rod-shaped core body arranged in the housing with a first end of the core body opposed to the first opening portion;

a writing pressure detection circuit arranged in the housing, which, in operation, detects a writing pressure based on movement of the core body;

a signal transmitter arranged in the housing, which, in operation, transmits a signal; and

an elastic block of material positioned inside of the housing near the first end of the core body, the elastic member including an exterior surface that faces the housing and a ring-shaped portion that protrudes outwardly from the exterior surface that faces the housing toward the housing and that is shaped to form a seal with an inner surface of the housing.

2. The position pointer of claim 1 wherein

the elastic block of material is positioned between the first end of the core body and the first opening portion.

3. The position pointer of claim 2 , comprising:

a pen tip chip having:

a main body portion positioned and sized to, in operation, pass through the first opening portion; and

a flange portion positioned in the housing, wherein

the flange portion is sized larger than the first opening portion.

4. The position pointer of claim 3 wherein,

when an external force is applied to the main body portion along a longitudinal direction of the housing from the first opening portion toward the first end of the core body, the elastic block of material biases the pen tip chip in a direction that counteracts the external force, and

when the external force is applied to the main body portion, the pen tip chip transfers the external force to the core body via the elastic block of material.

5. The position pointer of claim 4 wherein

the elastic block of material includes a biasing portion which, in operation, responds to the external force to bias the pen tip chip in the direction that counteracts the external force.

6. The position pointer of claim 4 , comprising:

an internal component arranged in the housing, wherein

the elastic block of material includes:

a biasing portion, which, in operation, biases the pen tip chip in a direction that counteracts the external force when the external force is applied to the main body portion from the first opening portion toward the first end of the core body; and

a holder portion to fasten the internal component to the housing.

7. The position pointer of claim 1 , comprising:

a component arranged in the housing, wherein

the elastic block of material includes a holder portion to fasten the internal component to the housing.

8. The position pointer of claim 7 wherein

the internal component is a ferrite core.

9. The position pointer of claim 1 , comprising:

a pen tip chip integral with the first end of the core body, with a step between the pen tip chip and the first end of the core body, the pen tip chip being sized and shaped to pass through the first opening portion, wherein

the elastic block of material includes a hole in a center portion of the elastic block of material,

the core body is sized and shaped to pass through the hole, and

a wall of the hole in the elastic block of material forms a seal with the step.

10. The position pointer of claim 1 , comprising:

an actuator including a flat portion arranged on an outside of a side surface of the housing, and a columnar portion arranged on an inside of a surface of the flat portion on the side of the housing, wherein

the housing includes a second opening portion on a longitudinal side surface,

the flat portion is sized not to pass through the second opening portion, and

the columnar portion is sized to pass through the second opening portion.

11. The position pointer of claim 10 , wherein

the flat portion comprises a material of relatively high elasticity, and

the columnar portion comprises a material of relatively low elasticity.

12. The position pointer of claim 10 , comprising:

an adhesive layer to attach the flat portion and the housing together.

13. The position pointer of claim 12 , wherein

the adhesive layer attaches the flat portion and the columnar portion together.

14. The position pointer of claim 1 wherein

the housing includes a third opening portion at a second longitudinal end, and

the position pointer includes:

a component holder fitted into the third opening portion; and

a seal to seal the component holder to the inner surface of the housing.

15. The position pointer of claim 14 , comprising:

an internal component arranged in the housing, wherein

the component holder fastens the internal component to the housing.

16. The position pointer of claim 1 wherein the elastic block of material comprises a film.

17. A system, comprising:

a position detection circuit; and

a position pointer, the position pointer including:

a tubular housing having a first opening portion at one longitudinal end;

a rod-shaped core body arranged in the housing with a first end of the core body opposed to the first opening portion;

a writing pressure detection circuit arranged in the housing, which, in operation, detects a writing pressure based on movement of the core body;

a signal transmitter arranged in the housing, which, in operation, transmits a signal; and

an elastic block of material positioned inside of the housing near the first end of the core body, the elastic member including an exterior surface that faces the housing and a ring-shaped portion that protrudes outwardly from the exterior surface that faces the housing toward the housing and that is shaped to form a seal with an inner surface of the housing.

18. The system of claim 17 wherein the position detection circuit is a capacitive position detection circuit.

19. The system of claim 17 wherein the position detection circuit is an electromagnetic position detection circuit.