JPH0286276A - Light collecting device for solid-state image pickup element - Google Patents

Abstract

PURPOSE:To prevent the deterioration in the performance such as shading or moire by providing a plate shaped optical fiber bundle on a lens array corresponding to each photoelectric conversion area on a solid-state image pickup element. CONSTITUTION:The progressing direction of a light made incident in a plate shaped optical fiber bundle 24 provided on a lens array 23 from lens systems 25, 26 of a camera is arranged unidirectionally depending on the direction of the fiber bundle 24. Then the light is collected by a lens array 23. That is, the incident angle of the light to the lens array 23 and the direction of the radiated light from the optical fiber bundle 24 are uniform independently of the lens systems 25, 26 of the camera, the optical axis 27, and the distance with the light incident position on the solid-state image pickup element 21, the lens array 23 is arranged so as to collect the light to each photoelectric conversion area 22 at all times. Thus, the occurrence of a defect such as shading or moire is prevented.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a light condensing device for a solid-state image sensor.

[Conventional technology]

The conventional light condensing device for a solid-state single-layer device corresponds to each photoelectric conversion region 32 on the solid-state image sensor 3I, as shown in the cross-sectional schematic diagram of a solid-state image sensor equipped with a light condensing device for a solid-state image sensor in FIG. The lens array 33 was made up of a lens array 33.

[Problem to be solved by the invention]

The angle of incidence of light onto the solid-state image sensor attached to the camera is determined by the camera lens system and the distance between the optical axis of the camera lens system and the light incident position on the solid-state image sensor, and the light incident position The incident angle of light deviates from the vertical as it goes to the periphery.

For this reason, in conventional light condensing devices for solid-state image sensors,
When changing the camera lens system for a certain lens array arrangement, the position of the image on the solid-state image sensor of the lens array changes, and there is a problem that the image of the lens array A may not be focused on the photoelectric conversion area. .

FIGS. 4(a) and 4(b) are schematic cross-sectional views for explaining the conventional example shown in FIG. This figure shows the state of the light beam when systems 45 and 46 are installed.

As shown in FIG. 4, the angle of incidence from the camera lens system 45, 46 at a certain point on the lens array 43 is different between the case of FIG. The position of the image of the lens array 43 on the lens array 41 also differs.

The distance from the optical axis of the camera lens system is r(, r2 (r+
The images on the solid-state image sensor 41 of points P, P2 on the lens array, which are
, (b) are respectively Ql' and Q2'. Here, Ql, Q2. Let the distances of Ql' and Q2° from the optical axis 47 of the camera lens system be Sl, S2. Sl゛, 52
', then S1°-st l < l S2'-52
1, and the positional deviation of the image of the lens array 43 increases as the distance between the optical axis 47 of the camera lens system and the position of incidence of light on the lens array 43 increases.
As you go to the periphery, it gets bigger.

In the case of the camera lens system 45 shown in FIG. 4, the arrangement of the lens array in FIG.
Assuming that the image of comes, that is, the light is focused on the photoelectric conversion region 42, ls+°-5,l<S2'-5
As expressed by equation 31, in the case of the camera lens system 46 shown in FIG. 3B, the focusing position of the lens array 43 deviates from the photoelectric conversion region 42 as it moves toward the periphery of the solid-state image sensor 41. Further, the thicker the lens array 43, the greater this deviation, which may cause deterioration in performance such as shading and moiré.

An object of the present invention is to provide a light condensing device for a solid-state image sensor that suppresses such drawbacks.

[Means to solve the problem]

The present invention is a light condensing device for a solid-state image sensor, which includes a lens array corresponding to each charge conversion area on the solid-state image sensor, and a plate-shaped optical fiber bundle provided on the lens array.

[Effect]

The traveling direction of light that enters the plate-shaped optical fiber bundle provided on the lens array from the camera lens system is aligned in one direction determined by the orientation of the fiber bundle. The light emitted from the optical fiber bundle is focused by a lens array provided below the optical fiber bundle.

The angle of incidence of light on the lens array, that is, the direction of the light emitted from the optical fiber bundle, remains the same regardless of the distance between the camera lens system and the optical axis of the camera lens system and the light incidence position on the solid-state image sensor. Therefore, the lens array can be arranged so as to always focus light on each photoelectric conversion region.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the drawings. FIG. 1 is a schematic cross-sectional view of a solid-state image sensor equipped with a condensing device for a solid-state image sensor according to an embodiment of the present invention. This condensing device for a solid-state image sensor is constituted by a lens array 3 corresponding to each photoelectric conversion region 2 on the solid-state image sensor 1, and a plate-shaped optical fiber bundle 4 on the lens array 3.

FIGS. 2(a) and 2(b) each show a point on the plate-shaped optical fiber bundle 22 provided on the lens array 23 at an arbitrary point off the optical axis in the embodiment of the present invention shown in FIG. 1. This figure shows the appearance of light rays when camera lens systems 25 and 26 with different incident angles are attached.

As shown in FIG. 2, the incident angle from the camera lens system at a certain point on the optical fiber bundle 24 is different between the case of FIG. 2 (a) and the case of FIG. The traveling direction of the light is aligned in one direction determined by the direction of the fiber bundle, so the angle of incidence of the light on the lens array 23 is determined by the angle of incidence between the camera lens system 25, 26, the optical axis 27 of the camera lens system, and the solid-state image sensor 21. It is uniform regardless of the distance from the upper light incident position.

The distance between the optical axis 27 of the camera lens system 25 and 26 is 'l
Point P3 on the optical fiber bundle 24 where r4<rJ<rJ
The image on the solid-state image sensor 21 of P4 is Q3 and Q4 in the case of (a), respectively, and 03"l in the case of (b), respectively.
Let it be Q4°. Here Q3. Q4. If the distances from the optical axis 27 of the camera lens systems 25 and 26 of Q3' and 04'' are respectively S3.S4+S and ``, s4'', then 53-s
3.54'-54.0, and when the arrangement of the lens array in FIG. 2 is the camera lens system 25 in FIG.
b) In the case of the camera lens system 26 shown in the figure, the light focusing position of the lens array 23 is located in the charging conversion area 22, and as in the conventional case, the light focusing position of the lens array deviates from the photoelectric conversion area, resulting in performance problems such as shading and moiré. There is no decrease in

〔Effect of the invention〕

According to the light condensing device for solid wood imaging elements of the present invention as described above, even if the lens system of the camera is changed, the lens array can be arranged so as to always focus light on each photoelectric conversion region, which is different from conventional solid-state imaging devices. It is possible to obtain a light condensing device for a solid-state image sensor that does not cause defects such as shading and moiré that occur in light condensing devices for devices.

[Brief explanation of the drawing]

FIG. 1 is a schematic cross-sectional view of a solid-state image sensor equipped with a condensing device for a solid-state image sensor according to an embodiment of the present invention, and FIG.
) and (b) are respectively a schematic cross-sectional view for explaining the present invention in detail in FIG. FIGS. 4(a) and 4(b) are schematic cross-sectional views for explaining the problems of the conventional example shown in FIG. 3, respectively. 1 21.31.41 ・・・Solid-state image sensor, 2.22
, 32.42... Photoelectric conversion region, 3.23, 33.4
3...Lens array, 4゜24...Optical fiber bundle, 2
5, 26, 45. 46...Camera lens 33rd toss °7 lei kaikai flash (a-2

Claims (1)

[Claims] 1. A condensing device for a solid-state image sensor, comprising a lens array corresponding to each photoelectric conversion region on the solid-state image sensor, and a plate-shaped optical fiber bundle provided on the lens array.