JPS6373204A - Color image pickup element - Google Patents

Abstract

PURPOSE:To eliminate the need for a costly IR filter and stage for incorporating said filter by compounding an IR absorbent to a spectral filter provided to the front face of an image pickup body. CONSTITUTION:This color filter is constituted of transparent resin layers 3a-3c and dyed gelatin 1, 2 layers. A layer 5 provided with the color filter to substitute an IR cut filter by adding the IR absorbent to the transparent resin layer is laminated on the uppermost layer. The similar effect is also expected even if the IR absorbent is added into at least one layer of the transparent resin layers 3a-3c. The effect is similar even if said absorbent is added to the dyed gelatin layer 1 which is a color sepn. layer and the gelatin layer 2 which is dyed to the color different from the gelatin layer 1. The stage for incorporating the Ir cut filter separately is eliminated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a color imaging element, and particularly to control of its color separation characteristics.

[Conventional technology]

In general, an image sensor is sensitive to infrared light as well as visible light, and therefore, if the image sensor is to be used for imaging only visible light, an infrared filter is naturally required.

Conventionally, for example, the infrared cut filter described in Japanese Utility Model Application Publication No. 56-155570 has used an interference film filter and a heat ray absorption filter, which are combined with a spectral filter to determine the color separation characteristics of a color image sensor. ing. This conventional device is shown in FIG. In the figure, 6 is an infrared cut filter, 7 is a spectral filter, and 8 is an image sensor.

[Problem that the invention seeks to solve]

In the conventional apparatus shown in FIG. 3, an infrared cut filter is placed in front of a CCD image sensor to assemble a color I stone image device. Such a configuration requires a step of incorporating an infrared cut filter into the color imaging device,
Another problem is that the infrared cut filter itself is not inexpensive.

This invention was made in view of the problems of the conventional ones as described above, and an object of the present invention is to obtain a color imaging device that can incorporate an infrared cut filter into an imaging device without separately providing an infrared cut filter. shall be.

[Means for solving problems]

The color image sensor according to the present invention has a spectral filter containing an infrared absorbing agent that significantly reduces the transmittance in the infrared light range, transmits light in the visible light range, and has an infrared cutting ability. It is.

[Effect]

In this invention, since the spectral filter contains an infrared absorbing agent, the spectral filter is given an infrared cutting ability that significantly reduces the transmittance in the infrared light range and transmits light in the visible light range. , the process of separately incorporating an infrared cant filter becomes unnecessary.

〔Example〕

Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

FIG. 1 shows an example of a color filter formed on the surface of a color image sensor according to an embodiment of the present invention, and the color filter is made of transparent resin.

3b, 3c and 1.2 layers of dyed gelatin. Further, in this embodiment, an infrared absorbing agent is added to the transparent resin layer, and M5, which has a color filter function in place of an infrared cant filter, is stacked on the top layer.

Figure 2 shows, for example, an infrared absorber (IF manufactured by Fujifilm).
-700'), and can be used in place of an infrared absorption filter.

In the above embodiment, the transparent resin layer 5 containing an infrared absorber is laminated on the top layer of the spectral filter, but the same effect can be obtained even if an infrared absorber is added to at least one of the transparent resin layers 3a, 3b, and 3c. The dyed gelatin N1 and the gelatin II, which are expected to be effective and are color separation layers! It may be added to the gelatin layer 2 dyed in a color different from that of I, and the same effect as in the above embodiment can be obtained.

Further, in the above embodiment, the image sensor 8 and the spectral filter 6
Although these are separate, it is of course applicable to an image sensor of the type in which the spectral filter 6 is directly attached to the image sensor 8.

In addition, in the above example, an example was shown in which IRF-700 manufactured by Fuji Film ■ was used alone as an infrared absorber, but if, for example, IRF-905 manufactured by Fuji Film A is used in combination with this absorbent, only IRF ~ 700 is used. It can provide infrared cutting ability over a wider range than when using
Can effectively cut light in the range of 00 to 950 nm.

Furthermore, in the above example, Fuji Film (IRF-700, IRF-905 made by !1B) was used as an infrared absorber, but the transmittance in the infrared region was significantly reduced and light in the visible light region was used. Of course, any material may be used as long as it is transparent.

〔Effect of the invention〕

As described above, according to the color image sensor according to the present invention, the spectral filter provided on the front surface of the image sensor body has an infrared
Since the A-absorbent is blended, an expensive infrared filter and its assembling process are unnecessary, and the device can be provided at a low cost.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing a color filter of a color image sensor according to an embodiment of the present invention, FIG. 2 is a diagram showing spectral characteristics of an infrared absorbing agent added to the device of FIG. 1, and FIG. 3 is a diagram showing a conventional color filter. FIG. 2 is a diagram showing a color image sensor of FIG. In the figure, 1 is a dyed gelatin layer (color separation layer);
2 is a gelatin layer dyed in a different color from 1 (color separation layer)
, 3a, 3b, and 3c are transparent resin layers, 4 is a substrate, 5 is a transparent resin layer added with an infrared absorber, 6 is a conventional infrared cut filter, 7 is a spectral filter, and 8 is an image sensor (
(line image element body).

Claims (5)

[Claims] (1) The image sensor body, which should have high sensitivity only in the visible light range, is combined with an infrared absorbing agent that significantly reduces transmittance in the infrared light range and transmits light in the visible light range, resulting in infrared cut. 1. A color image sensor, characterized in that the color image sensor is provided with a spectral filter and is provided with a spectral filter provided on the front surface of the image sensor main body. (2) The color according to claim 1, wherein the infrared absorber is blended in at least one of the lowermost layer, intermediate layer, or uppermost layer of the transparent resin layer constituting the spectral filter. Image sensor. (3) The color imaging device according to claim 1 or 2, further comprising a layer in which an infrared absorber is blended with a transparent resin on the uppermost layer of the spectral filter. (4) The color imaging device according to claim 1 or 3, wherein the infrared absorber is blended in a portion constituting a color separation layer of the spectral filter. . (5) The color imaging device according to any one of claims 1 to 4, characterized in that a plurality of types of infrared absorbers having different spectral properties are provided as the infrared absorbers.