JPS6098788A - Beam index tube device - Google Patents

Abstract

PURPOSE:To improve contrast by providing a reflection prevention diaphragm between a panel surface and a photosensor in a beam index tube. CONSTITUTION:An index signal emitted from a panel surface is sufficiently transmitted on a photosensor 2 surface which receives the index signal and a diaphragm for preventing reflection which shuts off a reflected light of light 3. This mechanism is designed to absorb and shield the reflected light reflected from the surface of the sensor 2, and to eliminate reflectiin of the light onto the panel surface of a beam index tube 1, thereby improving contrast of the tube 1.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a beam index tube device, and particularly to a beam index tube device suitable for a front lighting system in which index signals are received from the front of a panel.

[Background of the invention]

In recent years, this type of beam index tube device @1
A configuration as shown in the figure has been proposed.

That is, in the same figure, 1 has a light band of each color and an index phosphor layer on the inner surface of the panel, and upon being hit by an electron beam, the light emitted from the light band of each color and the index phosphor layer are emitted from the outer surface of the panel. A beam index tube 2 that emits an index signal is an optical sensor for receiving the index signal, which is disposed facing the outer surface of the panel of the beam index tube 1.

Although the beam index tube device 1 configured as described above is incident on the entire surface, the light 3 emitted by each color band light body is reflected on the front surface of the optical sensor 2, and the reflected light 4 is reflected on the panel of the beam index tube 1. The beam was incident on the surface of the beam index tube 1, causing a decrease in the contrast of the beam index tube 1. On the other hand, since this optical sensor 2 receives the index signal emitted from the panel surface of the beam index tube 1,
It is impossible to place it in a location that is not hit by optical signals from the panel surface. Therefore, a decrease in contrast due to the reflected light 4 from the optical sensor 2 was unavoidable.

[Purpose of the invention]

Accordingly, it is an object of the present invention to provide a beam index tube device that prevents the contrast of the beam index tube from decreasing due to reflected light from an optical sensor.

[Summary of the invention]

In order to achieve the above objects, the present invention provides anti-reflection means between the panel surface of the beam index tube and the optical sensor.

[Embodiments of the invention]

Next, embodiments of the present invention will be described in detail using the drawings.

FIG. 2 is a block diagram showing an example of a beam index tube device according to the present invention, and the same parts as in FIG. 1 are given the same reference numerals. In the same figure, the surface of the optical sensor 2 that receives the index signal is provided with an anti-reflection means, for example, an AR (Antl-Ref) that allows the index signal emitted from the panel surface to sufficiently pass through and blocks the reflected light of the light 3.
Anti-reflection film such as coating 5
is installed.

According to such a configuration, the reflected light 4 (see FIG. 1) reflected from the surface of the optical sensor 2 is absorbed and blocked by the anti-reflection film 5, and reflection on the panel surface of the beam index tube 1 is eliminated. Therefore, the contrast of the beam index tube 1 can be improved.

Further, when a suitable filter for wavelength selection is disposed on the front side of the optical sensor 2, the same effect as described above can be obtained by disposing an antireflection film 5 on the front side of this filter.

In addition, in the above-mentioned embodiment, a case was explained in which one anti-reflection means was provided on the surface of the optical sensor and in front of the optical sensor via the filter, but the present invention is not limited to this, and the optical sensor and the beam Of course, the same effect as described above can be obtained even if the trap is disposed anywhere between the index tube and the panel surface, for example, in the middle of the reflected light optical path or on the front side of the panel surface.

〔Effect of the invention〕

As explained above, according to the present invention, reflected light from the optical sensor or filter, which was a problem in front lighting type beam index tube devices, is eliminated.
An extremely excellent effect can be obtained in that the contrast of the beam index tube can be greatly improved.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a main part showing an example of a beam index tube device that has been proposed in recent years, and FIG. 2 is a block diagram of a main part showing an example of a beam index tube device according to the present invention. 1Φ... Beam index tube, 2... Optical sensor, 3... Light emitted by fluorescent material, 4... Reflected light, 5... Anti-reflection film. Figure 1 Figure 2

Claims (1)

[Claims] a beam index tube having each color band light body and an index phosphor layer provided on the inner surface of the panel; and an optical sensor disposed opposite to the panel surface of the beam index tube and receiving an index signal generated from the index phosphor layer. , comprising an anti-reflection means disposed between the panel surface of the beam index tube and the optical sensor to prevent reflection of each color changing light body light generated from the panel surface onto the panel surface. Beam index tube device.