JPH0634487A - Optical device for evaluating solid-state image pickup element - Google Patents

Abstract

PURPOSE:To easily evaluate the characteristic of a solid-state image pickup element which changes depending upon the incident angle of incident light in a wafer state by providing a diffusing member having a diffusion coefficient corresponding to the F-number of the diaphragm, section of the element. CONSTITUTION:A diaphragm section 3 and a diffusing plate 5 are respectively provided in the vicinity of a lens system 2 and in the vicinity of a CCD image pickup element 4 to be evaluated between the system 2 and element 4. The section 3 has a small F-number and large aperture. A diffusing plate having a diffusion coefficient corresponding to the F-number of the section 3 is used as the plate 5 so that a diffusion amount can be introduced to the element 4. Both the section 3 and plate 5 are constituted in switchable states. Since the light reaching the plate 5 through the section 3 having a small F-number is diffused by means of the plate 5 and introduced to the element 4, the incident angle thetaA of the light made incident to the element 4 becomes larger. Therefore, not only the evaluation of the characteristics of the element 4, such as sensitivity rising rate, image unevenness, smearing characteristic, etc., but also the evaluation and analysis of picture faults become possible.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solid-state image sensor evaluation optical apparatus suitable for use in, for example, characteristic evaluation of CCD image sensors.

[0002]

2. Description of the Related Art Conventionally, as such an optical device for evaluating a solid-state image pickup device, for example, one shown in FIG. 3 is known. That is, in this apparatus, the light from the light source 11 is condensed by the lens system 12 and is focused on the CCD image pickup device 14 (wafer state CCD image pickup device) to be evaluated via the diaphragm 13. It is configured. Then, the characteristics of the CCD image pickup device 14 are evaluated based on the signal obtained by the device. In this case, the F number of the diaphragm 13 is fixed to a predetermined value due to the configuration of the optical system.

[0003]

By the way, as the CCD image pickup device 14, the light receiving portion and the lens element are formed on the image pickup area where the light receiving portion is formed in accordance with the increase in density and resolution.
Corresponding microlenses are formed integrally with each other, and the light incident on a larger area than the light receiving portion is focused on the corresponding light receiving portion through the lens element to improve the sensitivity C
A CD image sensor has been proposed. In the CCD image pickup device 14, the characteristics of the image pickup device change depending on the incident angle θ of the incident light.
If the center position of the corresponding light receiving part is extremely deviated, it will be defective as an image sensor.
It is necessary to evaluate the CCD image pickup device 14 by changing the above.
However, in the case of the above-mentioned conventional example, since the F number of the diaphragm 13 is fixed to, for example, F10, it is not possible to evaluate the characteristics when the incident angle θ of the incident light is changed. In this case, in order to evaluate the characteristics in which the incident angle θ is changed, the CCD image pickup device 14 is cut out from the wafer, individual CCD image pickup devices are assembled, and the evaluation is performed using an evaluation optical device for this CCD image pickup device. Must be done, and as a result,
It takes a long time from the manufacture of the CCD image pickup device to the evaluation,
Further, there is a problem that a new assembly process of the CCD image pickup device is required.

The present invention has been made in view of the above points of the conventional example, and an object thereof is to evaluate a characteristic which depends on an incident angle of incident light in a wafer state for a solid-state image sensor. An object is to provide an optical device.

[0005]

According to the present invention, for example, as shown in FIG. 1, a solid-state image pickup device in which light from a light source 1 is guided to a solid-state image pickup device 4 to be evaluated through a diaphragm section 3 having a predetermined F number. In the element evaluation optical device, a diffusion member 5 having a diffusion coefficient according to the F number of the diaphragm 3 is provided in the vicinity of the solid-state imaging element 4.

[0006]

In the present invention having such a structure, the light reaching the diffusing member 5 via the diaphragm 3 having a predetermined F number is diffused by the diffusing member 5 and guided to the solid-state image pickup device 4, so that The incident angle θ _A of the incident light on the solid-state image sensor 4 can be increased without changing the basic configuration of the system.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. FIG. 1 shows a schematic configuration of an optical device for evaluating a solid-state image sensor according to the present invention. As shown in the figure, the apparatus of this embodiment is provided with a light source 1 and a condenser lens system 2 similar to those of the conventional example. A diaphragm 3 is provided near the lens system 2, and a diffusion plate 5 is provided between the lens system 2 and the CCD image pickup device 4 to be evaluated and near the CCD image pickup device 4. ing. Further, as shown in FIG. 2, an ND filter 6 for adjusting the light amount is provided between the diffusion plate 5 and the CCD image pickup device 4.

The CCD image pickup device 4 is in a state of a semiconductor wafer before being cut out and is composed of an element portion 4a and a microlens portion 4b formed thereon. The diaphragm 3 used in this embodiment has an F number of 1.2 to.
It corresponds to 5.6. That is, the F number is smaller and the opening is larger than that of the diaphragm of the conventional device.

On the other hand, for the diffusion plate 5, F
A diffuser having a diffusion coefficient corresponding to the number is used so that the diffused light is guided to the CCD image pickup device 4. The throttle 3
Both the diffusion plate 5 and the diffusion plate 5 are switchable.

In this embodiment having the above structure, F
Light reaching the diffuser plate 5 through the small number of diaphragms 3 is diffused by the diffuser plate 5 and guided to the CCD image pickup device 4, so that the incident light enters the CCD image pickup device 4 as shown in FIG. The angle θ _A becomes larger than the incident angle θ of the conventional device. Therefore, according to the present embodiment, it is possible to evaluate the characteristics of the CCD image pickup device 4 depending on the incident angle θ _A of the incident light, such as the rate of increase in sensitivity, image unevenness, smearing characteristics, and the like, and evaluate image defects. Analysis is also possible. Further, according to the present embodiment, since evaluation can be performed in a wafer state, it is possible to significantly reduce the time from the manufacture of the CCD image pickup device 4 to the evaluation and reduce the number of assembling steps.

The apparatus of this embodiment can also be used in combination with the conventional apparatus described above. That is, for example, when the F number of the diaphragm portion is 1.2 to 5.6, a diffusion plate having a diffusion coefficient corresponding thereto is switched, and the F number is 5.6 to 5.6.
In the range of 32, the conventional structure having only the diaphragm without using the diffusion plate is used. With this configuration, it is possible to evaluate the characteristics of the CCD image pickup device with respect to light having a wide range of incident angles.

The present invention can be applied not only to the CCD image pickup device described above but also to various solid-state image pickup devices.

[0013]

As described above, according to the present invention, since a diffusing member having a diffusion coefficient according to the F number of the diaphragm is provided in the vicinity of the solid-state image pickup device to be evaluated, incident light is incident. It is possible to evaluate the characteristics of the solid-state image sensor depending on the angle, such as the rate of increase in sensitivity, image unevenness, smearing characteristics, and the like, and it is also possible to evaluate and analyze image defects. Further, according to the present invention, since evaluation in a wafer state is possible, it is possible to significantly reduce the time from the manufacturing to the evaluation of the solid-state imaging device and the apparatus using the same, and to reduce the number of assembling steps.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of an embodiment of an optical device for evaluating a solid-state image sensor according to the present invention.

FIG. 2 is a schematic configuration diagram showing a main part of the embodiment.

FIG. 3 is a schematic configuration diagram of a conventional solid-state image sensor evaluation optical apparatus.

[Explanation of symbols]

 1 light source 3 diaphragm 4 CCD image sensor 5 diffuser plate

Claims (1)

[Claims] 1. A solid-state image sensor evaluation optical apparatus for guiding light from a light source to a solid-state image sensor to be evaluated through a diaphragm section having a predetermined F number, wherein the diaphragm section is provided near the solid-state image sensor. An optical device for evaluating a solid-state image sensor, comprising a diffusion member having a diffusion coefficient according to the F number.