JPS6346129A - Endoscope - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to an endoscope having a solid-state image sensor at its tip.

[Prior Art] Recently, endoscopes have been developed that use solid-state imaging devices instead of optical fiber bundles as imaging optical systems. For example, as shown in Japanese Unexamined Patent Publication No. 61-65215, an objective lens frame holding a plurality of lenses is attached to the attachment hole of the tip body, and the exit side of the objective lens is a solid! f
An i-group element is provided. In this solid-state Wi image element, on the package substrate! A lil image element chip is provided, and an image area formed on this chip is provided with a cover glass. Also, inside? J! In an attempt to make the solid-state imaging device smaller in order to reduce the diameter of a, package substrates and cover glasses are being made smaller.

[Problems to be Solved by the Invention] However, when the cover glass is made smaller in order to make the solid-state image sensor smaller, among the light rays that enter through the objective lens, the light rays that are aimed at the side surface of the cover glass are transmitted through the side surface or It reflects off the sides and reaches the image area of the chip, creating a flare. This flare can be prevented by making the cover glass as large as the outer diameter of the package substrate, but this poses the problem of increasing the size of the solid-state image sensor.

An object of the present invention is to provide an endoscope in which flare does not reach the image area of the chip even when the solid-state w1e element is downsized.

Means for Solving Problems L] The present invention provides a means for solving the problem of W through the side surface of the cover glass of a solid-state
This is an endoscope that has a solid-state image sensor at its tip, which has a light shielding means to prevent light from entering the i-image element chip.

[Function] The light beam directed to the side surface of the cover glass through the objective lens of the endoscope is prevented from being transmitted or reflected from the side surface by the light shielding means, thereby preventing flare from entering the image sensor chip.

[Example] Hereinafter, an example of the present invention will be described based on FIGS. 1 to 3. FIG. 1 is a sectional view showing the distal end portion of the endoscope of the present invention. The distal end portion 2 of the insertion portion of the endoscope 1 has a distal end component main body 3, and the main body 3 is provided with a first attachment hole 4 and a second attachment hole 5. An objective lens frame 8 holding a cover glass lens 6 and a plurality of objective lenses 7 therein is inserted and fixed into the first attachment hole 4 from the distal end side. A solid-state imaging device 10 is provided at the rear end of the objective lens frame 8 . This solid-state imaging device 10 has a solid-state imaging device frame 11
An optical path conversion prism 12 and a correction prism 13 are bonded to each other, a solid-state photography vIA element 14 is bonded to the correction prism 13, and a frame 11 is fixed to the main body 3. still,
The optical path conversion prism 12 reflects the optical path twice within the prism to make the optical axis oblique to the optical axis of the objective lens 7, and the correction prism 13 corrects the optical axis so that it exits at right angles to the exit surface of the prism. Thus, the solid-state Wi image element 14 is arranged obliquely with respect to the optical axis of the objective lens 7.

As shown in FIGS. 2 and 3, this solid-state Wi image element 14 has an LFI image element chip 16 mounted on a package substrate 15, and this chip 16 has an image area 17 of a predetermined area and a terminal 18. It is formed. Package board 1
5 is provided with one pad corresponding to the terminal 18 of the chip 16, and both are bonded by a wire 20. Also, a cover glass 2 is placed on the image area 17.
1 are bonded to each other, and a color filter array 22 is formed on the surface of the cover glass 21 that is bonded to the image area 17. A black coating film 23 is formed on the side surface of this cover glass 21.
A sealing plastic 24 is formed on the side surface of the cover glass 21 to cover the wire 2o and have a thickness substantially the same as the top surface of the cover glass 21.

Note that an opaque black plate may be placed on the side surface of the cover glass 21, and the color filter array may also be formed by an on-chip filter method.

The solid-state image sensor 14 is fixed on a flexible substrate 25 and electrically connected to it. In addition, the flexible substrate 2
When this solid-state Wi image device M10 is assembled into the endoscope tip 2 on the top and back surfaces of the endoscope 5, there are various electrical components 26 in the space.
is installed. One end of the flexible substrate 25 is bent and stored within the tip portion 2, and a signal line 27 such as a coaxial cable is connected to that portion.

On the other hand, the second attachment hole 5 is provided with a cover lens 30 forming an illumination window, and one end portion of a light guide fiber bundle 31 is connected thereto. Illumination light from a light source device (not shown) enters the other end of the light guide fiber bundle 31, and the light beam emitted from one end illuminates the observation site.

According to such an endoscope 1, light rays within the field of view that enter and pass through the upper surface of the cover glass 21 of the solid-state image sensor 140 reach the image area 17 of the 1ffl image element chip 16. Also, some of the light rays a outside the field of view enter the side of the cover glass 21 through the sealing plastic 24, and some of the light rays outside the field of view reach the side of the cover glass 21 and are reflected by the side. , the rays a and b are applied to the side surface of the cover glass 21! The light is blocked and absorbed by 23, and is transmitted or reflected from the side to create an image area 1.
7 and does not cause flare, a good observation image can be obtained.

FIG. 4 shows a second embodiment of the present invention, in which only the solid-state image sensor 14 is shown. In this second embodiment, the package substrate 15
After attaching the image sensor chip 16 on top and bonding with the wire 20, the cover glass 21 is bonded, and the sealing plastic 24 is attached to the side of the cover glass 21 with the wire 2
It is formed covering 0. This sealing plastic 2
A black coating film or an opaque plate 32 is disposed on the upper surface formed on the same surface as the cover glass 21 of No. 4.

The solid-state ms element 14 of this second embodiment is attached to the distal end portion 2 of the endoscope.
Even if the camera is placed in a
Since the light is blocked before reaching the side surface of the image area 17, the flare does not enter the image area 17.

Note that the light shielding means is not limited to the above-mentioned embodiments, and any light shielding means may be provided on the solid-state image sensor 14 so as to be able to block light from entering the side surface of the cover glass 21.

[Effects of the Invention] As described above, the present invention provides an image of l1l (
Since the light shielding means for blocking light from entering the II element chip is provided, it is possible to prevent light from entering and reflecting from the side surface of the cover glass, and a good observed image without flare can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of the distal end of an endoscope according to a first embodiment of the present invention;
FIG. 2 is a plan view of the solid-state image sensing device, FIG. 3 is a sectional view of FIG. 2, and FIG. 4 is a sectional view of the solid-state LFI image device used in the second embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Endoscope, 2... Tip part, 14... Solid-state image sensor, 16... Ifi image element chip, 21... Cover glass, 23. 32... Light shielding means.

Claims (1)

[Scope of Claims] A solid-state image sensor having a cover glass for sealing the image sensor chip on a package substrate, and a light shielding means for blocking light from entering the element chip through the side surface of the cover glass is attached to the tip. Endoscope with.