JPS6023941A - Bias light apparatus - Google Patents

Abstract

PURPOSE:To avoid deterioration in uniformity and application coefficientcy of light by respectively providing a protrusion to the one of the external circumference of lens and internal circumference of box and a groove with which the protrusion is engaged to the other and inserting said protrusion into the groove and then bonding them or pressurizingly inserting protrusion into the groove. CONSTITUTION:A lens 15 is provided with a protrusion at the external circumference and a cover 17 is provided with a groove 17a with which a protrusion 15a of lens 15 is engaged at the internal circumference. The protrustion 15a of lens 15 is inserted pressurizingly into the groove 17a of the cover 17 or the protrusion 15a is inserted into the groove 17a and the interface of them is fixed by bonding. Even when a bonding agent is used, since it is applied to a part of the protrusion 15a and groove 17a being apart from the surface of lens 15, the bonding agnet does not reach the surface of lens 15.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to an improvement in a bias light device that supplies bias light from the front side of the face plate of an image pickup tube.

[Background of the invention]

Generally, in an image pickup tube, residual Oi! In order to improve the characteristics, a photoconductive film deposited on the face plate is irradiated with minute light (t-bias light) from the front side of the face plate.

FIG. 1 shows a cross-sectional view of a conventional bias light device. As shown in the figure, the bias light device 1 includes a light source 2 made of a light emitting diode, a small lamp, etc., a lens 5 made of acrylic resin that diffuses the light source 20 and irradiates it onto the front surface of the face plate 4 of the image pickup tube 3, and A that stores light@2 and lens 5
B8 Consists of a box 8 consisting of a holder 6 made of resin and a lid 7.

In such a bias lie (a Nt l), if the lens 5 and the box 8 are not sufficiently fixed, the lens 5 and the box 8 will rub against each other due to vibrations, shocks, etc. to the imaging device, and static electricity will be generated. When static electricity is generated in this way, the static electricity jumps into the video signal, causing noise in the image and damaging the image.

Therefore, conventionally, the lens 5 is fixed to the lid 7 using an adhesive 9. However, since such a hard structure requires the adhesive 9 to be placed on the side surface of the lens 5 and the inner surface of the lid 7, the adhesive 7 protrudes and stains the surface of the lens 50, resulting in poor light uniformity and utilization. there were.

[Purpose of the invention]

The present invention has been made in view of the above-mentioned drawbacks of the prior art, and it is an object of the present invention to provide a bias light device that does not deteriorate the uniformity and utilization rate of light.

[Summary of the invention]

In order to achieve these objects, the present invention improves the efficiency of the lens system insertion method.

[Embodiments of the invention]

Next, the present invention will be explained with reference to illustrated embodiments.

FIG. 2 is a side view showing a side example of the bias light device according to the present invention. As shown in the same figure, "/C
, the source 2 and the holder 6 have the same construction as in FIG. The lens 1 is provided with a projection 58 on its outer periphery as shown in FIG. 3, and the lid I7 is provided with a groove 72 on its inner periphery as shown in FIG. ing. Then, insert the protrusion 15a of the lens 15 into the groove of the lid 17.
78, or the protrusion 15a (<groove 17 aK
Insert this part and glue it in place. In the case of press-fitting, the adhesive naturally does not protrude, but even if adhesive is used, the parts to which the adhesive is applied are the protrusion +58 and a part of the groove 17a that are far from the surface of the lens I5, so the lens 150
No adhesive will ooze out onto the surface. In addition, lens 15
Even a prism has the same effect.

5 and 6 show other embodiments of the invention.

In this embodiment, contrary to the above-mentioned embodiment, boxwood 15b=e is provided on the outer periphery of the lens 15, and a groove 15c is provided on this brim 15b, and a protrusion 17 on the inner periphery of the lid 17 is attached to the groove 15C. 'bi has been established. Even if formed in this way, the same effects as in the above embodiment can be obtained.

〔Effect of the invention〕

As is clear from the above description, according to the bias light device of the present invention, there is no adhesive extrusion, so that generation of static electricity can be completely prevented without deteriorating the uniformity of light and the utilization rate.

[Brief explanation of drawings]

Fig. 1 is a sectional view of a conventional bias light device, Fig. 2 is a sectional view showing an embodiment of the bias light device according to the present invention, Fig. 3 is a side view and a sectional view of the lens, and Fig. 4 is a lid. 5 and 6 show other embodiments of the present invention, FIG. 5 is a sacral view and a sectional view of the lens, and FIG. 6 is a sectional view and a sacral view of the lid. It is a J-side view. 1... Bias light device, 2... Light source, 3...
...Image tube, 4...Front plate, 6...Holder,
15...Lens, 15a...Protrusion, 15C...
...Groove, 17...None, 17a...-2α

Claims (1)

[Claims] In a bias light device comprising a light source, a lens that diffuses the light from the light source and irradiates it onto the front surface of the face plate of the image pickup tube, and a box that houses the light source, the lens, and the entire body, the outer periphery of the lens and the inner periphery of the box are or 10,000 protrusions
and a groove t into which the protrusion is mounted, and the protrusion is inserted into the groove and adhered or press-fitted therein.