JPS5933074Y2 - light pen - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to light men in CRT displays.

A conventional light pen is shown in FIG.

Reference numeral 1 denotes a light guide, which is integrated with a metal cylinder 4.

2 is a light receiving element, 5 is an LED, 6 is a switch 0N10FF
This is a phototransistor for use.

Reference numeral 3 denotes a compression spring that pushes the metal tube 4 and the light guide 1 toward the pen tip.

When the light guide 1 is pressed against the CRT screen against the compression spring 3, the metal tube 4 moves around the light guide 1, and the LED 5 and the phototransistor 6 for switching ON/OFF enter into the metal tube 4. , this phototransistor 6
is turned on by receiving the light from the LED 5 reflected within the metal cylinder 4.

In conjunction with the ON of this phototransistor 6, the light receiving element 2
The light received from the CRT is converted into an electrical signal and transmitted to the outside of the light pen.

When the light guide 1 is not pressed, the phototransistor 6 protrudes from inside the metal cylinder 4, so the light from the LED 5 is not transmitted to the phototransistor 6, and the phototransistor 6 is turned off.
Because of this state, the light received by the light receiving element 2 is converted into an electrical signal, but is not transmitted to the outside of the light pen.

However, according to this configuration, there are 5 LEDs inside the light van,
It is necessary to provide a phototransistor 6 and a light receiving element 2, which makes the structure complicated, and at the same time, it is necessary to lead out many lead wires from the light pen, which increases the risk of wire breakage.Also, home TVs are generally built on hot chassis. This was dangerous because when the light pen was used to convert it into an electrical signal, the potential of the chassis might be too low for the light pen.

The present invention was developed in view of these points, and the light is blocked or introduced depending on the relative distance between the permanent magnet and the magnetic fluid, and the introduced light is converted into a light beam using a cabtical fiber. The present invention provides a light pen that is guided to the outside of the pen and converted into an electrical signal.

The present invention will be explained with reference to the drawings.

FIG. 2 is a sectional view showing an embodiment of the light pen of the present invention.

Reference numeral 1 denotes a light guide that comes into contact with the CRT screen, and is provided so as to be freely retractable from the pen case 8.

A cylindrical body 9 is integrally formed with the light guide 7, has a diameter larger than that of the light guide 7, and is in sliding contact with the inner surface of the case 8.

10 is a protrusion for preventing removal provided inside the case 8;
1 is a compression spring for pushing the light guide 7 toward the pen tip;
12 is a permanent magnet fixed to the inner periphery of the cylindrical body 9.

Reference numeral 13 denotes an optical fiber that guides light to a photoelectric conversion section outside the light pen, and is located along the same optical axis as the light guide 7.

Reference numeral 14 denotes a transparent container containing an opaque magnetic fluid 15, which is located along the optical axis of the light guide 7 and the optical fiber 13, and is attached so as to block the optical path.

This magnetic fluid 15 is refined by crushing ferrite or magnetite into fine particles together with a carrier fluid in a grinder, and is FERRQFLUIDIC8.
From COR-PORATION to FERROFLUID (
It is sold under the trade name ferrofluid.

Next, the operation will be explained.

When the light guide 7 is not pressed, the magnetic fluid 15 is not receiving any force from the permanent magnet 12, so the magnetic fluid 15
is in a state of blocking the light introduced from the light guide T.

When the light guide 7 is pressed on the CRT screen, the cylinder body 9 moves in conjunction with the light guide I against the compression spring 11, and the permanent magnet 12 fixed to the inner circumference of the cylinder body 9 attracts the magnetic fluid 15. It will be located on the outer periphery.

The magnetic fluid 15 is drawn toward the permanent magnet 12 to open an optical path in the center, and the light from the light guide 7 is guided through the optical fiber 13 to a photoelectric conversion section outside the light pen, where it is converted into an electrical signal. .

When the light guide 7 is separated from the CRT screen, the cylinder body 9 is pushed toward the pen tip by the force of the compression spring 11 and returns to its initial state, and the magnetic fluid 15 is less affected by the permanent magnet 12. The light diffuses into the transparent container 14 and blocks the light introduced from the light guide 1.

As mentioned above, the light pen of the present invention introduces and blocks light using the magnetic force of a permanent magnet against the magnetic fluid, and the introduced light is guided to the outside of the light pen through an optical fiber, where it undergoes photoelectric conversion and obtains an electrical signal. Therefore, there are no electrical elements inside the light pen, and the structure is simple and highly productive.It is also highly durable, and there is no fear of disconnection, which occurred frequently in the past, making it highly reliable. Obtains a light pen.

In addition, since the light pen of the present invention is connected to the main body of the device only by optical fiber, there is no fear that the potential of the chassis will be shallow to the light pen, and safety is extremely high.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a conventional light pen, and FIG. 2 is a sectional view of the light pen of the present invention. 7...Light guide, 12...Permanent magnet,
13...Optical fiber 14...
...Transparent container, 15...Magnetic fluid.

Claims (1)

[Scope of utility model registration request] In light pens that use optical fibers to guide light from a CRT screen to the main body of the device for data input, a magnetic fluid is used as the main component between the optical fiber and the light guide that comes into contact with the CRT screen. At the same time, a permanent magnet whose relative distance to the light shielding member is variable is provided. This light pen opens the optical path between the optical fiber and the optical fiber, and when the optical guide is separated from the CRT screen, the optical path between the optical fiber and the optical fiber is blocked due to the magnetic force of the permanent magnet.