JPH08211336A - Solid-state image pickup element with optical low-pass filter - Google Patents

Abstract

PURPOSE: To enhance alignment accuracy and to reduce a cost by constituting a phase grating optical low-pass filter in such a manner that this filter is formable by the same method as a microlens process for a CCD. CONSTITUTION: The upper part of a lens layer 4 existing in the upper part of the element part 1 of the CCD is provided with a transparent resin layer 5 consisting of a resin having the refractive index smaller than the refractive index of this lens layer 4 and is provided thereon with a grating shape layer 6. The relation 1--(ndo-ndu)/(ndo-1)<Lo.(ndo-1)/ Lu.(ndo-ndu)}<1+(ndo-- ndu)/(ndo-1) is satisfied when the required distance of the case the spacing between the lens layer 4 and photodetecting parts 3 (if the part above the lens layer 4 formed in the conventional manner is air) is converted to the air is defined as Lo; the required distance converted to the air from the lens layer 4 to the photodetecting parts 3 of the case the lens layer 4 is covered with the transparent resin layer 5 as Lu; the refractive index of the transparent resin layer 5 as ndu and the refractive index of the lens layer 4 as ndo.

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 pickup device such as a CCD for spatially discretely sampling an optical image. More specifically, an image sensor with an optical low-pass filter, which is provided with an optical low-pass filter for removing high spatial frequency components that cannot be resolved by a solid-state image sensor, from an object image formed on an image-capturing surface and the image sensor The present invention relates to a camera lens and a video camera.

[0002]

2. Description of the Related Art In an image pickup device that performs spatially discrete sampling, there is an upper limit to the spatial frequency that can be resolved, so spatial frequency components exceeding the limit are removed or attenuated by an optical low pass filter. A crystal was used as this optical low-pass filter, but in order to obtain the desired low-pass effect, a sufficient space for arranging the crystal in the optical system is required, and the price of the crystal itself is expensive. .

Therefore, in recent years, it has been proposed to obtain an optical low-pass effect by using the diffraction effect of a phase grating, which is a kind of diffraction grating, without using quartz. When the phase grating having the effect as the conventional optical low-pass filter is integrated with the solid-state image pickup device, the one formed on a substrate such as glass is attached to the sensor portion of the image pickup device afterwards. For example, there is one in which a phase grating as shown in FIG. 7 disclosed in Japanese Patent Laid-Open No. Hei5-273501 is retrofitted to a sensor portion of a solid-state image sensor.

In FIG. 7 showing a solid-state image pickup device using the above-mentioned conventional phase grating, 51 is a sensor portion, and a bead-shaped or columnar spacer 52 is provided around the sensor portion, and a phase grating 53 is provided through the spacer 52 to form a sensor portion. It is configured to be fixed to 51. Further, these phase gratings are enclosed by a sealing glass 54 in a package 55 of a solid-state image sensor.

[0005]

In the conventional solid-state image pickup device in which the phase grating having the effect of the optical low-pass filter is arranged very close to the image pickup surface, the periodicity direction of the phase grating and the pixel of the image pickup device are used. It is necessary to match the direction of the periodicity of 1 with high accuracy. However, when enclosing the optical low-pass filter, there is a high possibility that the sensor unit 51 is attached at an angle or is rotated with respect to the optical axis direction. The mounting error due to the inclination and rotation with respect to the optical axis direction causes the phase grating periodicity to deviate from a desired value with respect to the pixel period of the image sensor, and causes an error in the characteristics of the optical low-pass filter. It was Therefore, if the mounting accuracy is increased to prevent an error, the cost for mounting becomes high.

The present invention has been made in view of the above problems, and by using a method that can be manufactured by the same method as the microlens process of CCD, it is possible to improve the alignment accuracy and reduce the cost. An object of the present invention is to provide a solid-state image sensor with an optical low-pass filter that uses the diffraction effect of a grating.

[0007]

In order to solve the above-mentioned problems, a solid-state image pickup device with an optical low-pass filter according to the present invention comprises an element portion for receiving incident light and performing photoelectric conversion, and a microlens above the element portion. A solid-state imaging device having a lens layer having, wherein a transparent resin layer filled with a transparent resin having a refractive index lower than that of a material of the lens layer is provided from a surface of the lens layer, the transparent resin layer It is characterized in that a lattice-shaped layer having an uneven shape is provided on the above.

In the solid-state image pickup device having the above structure, a plurality of light receiving portions for generating electric charges by the light received by the element portion and a transfer portion for transferring the electric charges generated in the respective light receiving portions are formed on the semiconductor substrate. It is preferable that the lens layer is provided on the upper portion of the element portion, and the lens layer is configured to collect incident light to the light receiving portion in each region corresponding to each light receiving portion.

Further, in the solid-state image pickup device having the above structure, a color filter layer is provided on the element part, and the lens layer located above the color filter layer collects incident light to the light receiving part. It is preferable that the processing is performed for each area corresponding to.

Further, the solid-state image pickup device of the present invention is a solid-state image pickup device having an element portion for receiving incident light and performing photoelectric conversion, and a lens layer having a microlens above the element portion. An intervening layer made of a transparent resin material is provided between the element part and the transparent resin layer is provided by filling the surface of the lens layer with a transparent resin having a refractive index lower than that of the material of the lens layer. A lattice-shaped layer made of a transparent resin and having an uneven shape is provided on the resin layer.

Further, in the solid-state image pickup device having the above construction, the intervening layer between the lens layer and the element portion is formed of the material of the dome-shaped portion of the microlens, and the microlens receives the incident light. It is preferable that the light is condensed on each region corresponding to each light receiving portion.

Further, in the solid-state image pickup device having the above structure, it is preferable to provide a color filter layer between the element portion and the lens layer. Further, in the solid-state imaging device having the above configuration, the refractive index of the microlens is ndo, the refractive index of the transparent resin of the transparent resin layer filling the microlens is ndu, and the microlens is not filled with the transparent resin. The distance when converted to air from the light receiving surface of the optical element is Lo, and it is necessary when converted to air from the lens to the light receiving surface of the element when the microlens is filled with a transparent resin having a refractive index ndu. When the distance is Lu, the relationship between the refractive index and the distance between the transparent resin layer, the microlens and the light receiving surface of the optical low pass filter is expressed by the formula: 1- (ndo-ndu) / (ndo-1) < Lo · (ndo−1) / {Lu · (ndo−ndu)} <1+ (ndo−ndu) / (ndo−1) (1) is preferably satisfied.

Further, in the solid-state image pickup device having the above structure, it is preferable that the transparent resin layer filling the lens layer has an infrared absorbing property. In addition, in the solid-state image sensor having the above structure, it is preferable that the intervening layer provided below the lens layer has an infrared absorbing property.

A video camera of the present invention is a video camera comprising a solid-state image pickup device and a lens system, characterized by including the solid-state image pickup device with an optical low-pass filter.

Further, it is preferable that the video camera having the above-mentioned structure is provided with the solid-state image pickup device with the optical low-pass filter.

[0016]

As described above, the solid-state image pickup device with an optical low-pass filter according to the present invention is a solid-state device having an element section for receiving incident light and performing photoelectric conversion, and a lens layer having a microlens above the element section. An imaging device, wherein a transparent resin layer filled with a transparent resin having a refractive index lower than that of the material of the lens layer is provided from the surface of the lens layer, and a grating having an uneven shape on the transparent resin layer The shape layer is provided. Therefore, the phase grating can be manufactured in the same process as the process of manufacturing the lens layer above the element portion, and the alignment for retrofitting the phase grating is not necessary, and the tilt with respect to the element portion and the rotation with respect to the optical axis direction are not necessary. The phase grating can be formed integrally with the image sensor with high accuracy without causing a deviation in direction or the like. As a result, the process for alignment can be simplified, the occurrence of defective products such as characteristic changes due to positional deviation can be suppressed, and the cost can be improved.

In the solid-state image pickup device having the above-mentioned structure, the device section has a light-receiving section and a transfer section for transferring charges generated in each light-receiving section, which are formed on a semiconductor substrate to collect incident light to the light-receiving section. According to the preferable configuration in which the lens layer is formed so that the light is emitted in each region corresponding to each light receiving unit, the light beam can be guided to each light receiving unit with little loss, and the sensitivity of the solid-state imaging device can be improved. .

In the above solid-state image pickup device, a color filter layer is provided on the element portion, and the lens layer located above the color filter layer is used to collect incident light to the light receiving portion. In addition to the above, according to the preferable configuration performed for each region, the color filter limits the wavelength band of the light beam incident on each light receiving portion, and thus is suitable for color.

According to the solid-state image sensor with an optical low-pass filter of the present invention, an intervening layer made of a transparent resin is provided between the lens layer and the element portion.
Since the phase grating can be formed integrally with the image sensor with high accuracy, it can be formed without causing an inclination with respect to the element portion and a deviation of the rotation direction with respect to the optical axis direction, and the process for alignment is simplified. It is possible to suppress the occurrence of defective products such as characteristics change due to the change in the position and the positional deviation, and to reduce the lens curvature of the lens layer.

In the solid-state image pickup device, according to the preferable structure in which the intervening layer is formed of the material of the dome-shaped portion of the microlens, the manufacturing process can be simplified in addition to the above-described actions and effects. The product yield can be improved.

Further, in the above-mentioned solid-state image pickup device, according to the preferable constitution in which the color filter layer is provided between the above-mentioned element portion and the lens layer, in addition to the above-mentioned actions and effects, colorization is possible.

Further, according to the preferable construction in which the optical low-pass filter of the solid-state image pickup device satisfies the following expression (1), it is possible to more effectively guide the light rays to the respective light receiving portions in addition to the above-mentioned actions and effects. The space can be made to have an optimum size, and the effect and the downsizing can be compatible. Also, the process for alignment can be simplified,
It is possible to suppress the occurrence of defective products such as a change in characteristics due to positional deviation, and it is possible to reduce costs.

Further, according to the preferable construction in which the resin material filling the lens layer of the solid-state image pickup device has infrared absorption, in addition to the above-mentioned actions and effects, the long wavelength component can be removed more reliably, Can be miniaturized.

Further, according to the preferable structure in which the intervening layer provided below the lens layer of the solid-state image pickup device having the above-mentioned structure has infrared absorbing property, in addition to the above-mentioned actions and effects, the long wavelength component can be removed. Yes, it can be miniaturized.

The video camera of the present invention is a video camera including a solid-state image pickup device and a lens system, and includes the solid-state image pickup device with the optical low-pass filter. It is possible to improve the reliability and downsize.

Further, according to the preferable structure in which the video camera having the above-mentioned structure is provided with the solid-state image pickup device with the optical low-pass filter, it is possible to reduce the characteristic change due to the positional deviation and to improve the reliability. And can be further miniaturized.

As described above, the solid-state image sensor of the present invention is
A phase grating having the effect of an optical low-pass filter is provided on the solid-state image sensor, and it is possible to integrally manufacture the solid-state image sensor and the phase grating in the same process as the process of manufacturing the microlens. Therefore, the alignment for retrofitting the phase grating becomes unnecessary, and the phase grating can be formed integrally with the image pickup element with high accuracy without causing the inclination with respect to the element portion and the deviation of the rotation direction with respect to the optical axis direction. As a result, it is possible to simplify the process for alignment, suppress the occurrence of defective products such as changes in characteristics due to displacement, and reduce costs.

[0028]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a partially cutaway front view showing a part of a solid-state image pickup device with an optical low-pass filter according to a first embodiment of the present invention.

As shown in FIG. 1, in this embodiment, the solid-state image pickup device with an optical low-pass filter has a light receiving portion
An element unit 1 having 3, 3, ..., And a microlens 4
It is formed of a lens layer 4 having a, 4a, 4a, ..., A transparent resin layer 5, and an uneven grid-shaped layer 6. The solid-state imaging device of the present embodiment can obtain the same function as that of the conventional phase grating, and the thickness can be 4 to 7 mm thinner than that of the conventional crystal filter by the thickness of the crystal. it can.

The element section 1 includes predetermined light receiving sections 3, 3,
Transfer units (not shown) for transferring the charges generated in the respective light receiving units 3 are formed on the semiconductor substrate 2. The light receiving unit 3 has a photoelectric conversion element including a photoconductive semiconductor, a photodiode, a transistor, etc., receives the incident light, performs photoelectric conversion, and generates an electric charge according to the intensity of the received light.

The lens layer 4 is provided on the element part 1,
The incident light is condensed on the light receiving portions 3, 3, 3 ,.
The micro lenses 4a, 4a, 4a, ... Are provided for each region corresponding to. The microlens 4a is formed integrally with the upper surface of the lens substrate 4b. As a material for the lens layer 4, a transparent resin such as an acrylic resin, a polyethylene terephthalate resin, a polycarbonate resin, a polystyrene resin, a polysulfone resin, or a polyvinyl alcohol resin is used. The light ray incident from the lens layer 4 enters the light receiving surface of the light receiving section 3 of the element section 1.

The transparent resin layer 5 is made of a transparent resin having a refractive index lower than that of the lens layer 4 so that the microlenses 4a,
A filled resin layer 5a in which the surface portions of 4a, 4a, ...
It is formed from the main body layer 5b. The refractive index of the transparent resin layer 5 is lowered by using a resin of a different type from the lens layer 4 and by changing the composition of the material added with the same type of resin, thereby increasing the difference from the lens layer 4. You may. If the difference between these refractive indices is large, the radius of curvature of the microlens 4a can be reduced, and the transparent resin layer 5
Thickness can be reduced.

The grid-shaped layer 6 is provided with projections 6a, 6a, 6a, ... on the surface of the transparent resin layer 5 in a grid-like arrangement to form an uneven shape. The cross-sectional shape of the protrusion 6a of the lattice-shaped layer 6 is formed into a lens shape, a trapezoidal shape, a rectangular shape, a shape with rounded corners, or the like.

A gap layer 11 between the element portion 1 and the lens layer 4
May be made of the transparent resin as described above for the purpose of integration, and may be the same as the resin of the lens layer 4. Like the solid-state image sensor of this embodiment, the microlenses 4a, 4a, 4
Since the surface portions a, ... Are filled with the filling resin layer 5a and the main body layer 5b is continuously provided, the effect of arranging the phase grating at a distance from the microlens 4a can be obtained.
Further, since the lattice-shaped layer 6 is provided on the transparent resin layer 5, the protrusion 6a of the lattice-shaped layer 6 can provide an effect as a phase grating. When the difference in refractive index between the microlens 4a and the transparent resin layer 5 is small, the curvature of the microlens 4a is large when the distance from the lens layer 4 having the microlens 4a to the element portion 1 is the same as the conventional one. Therefore, the height of the microlens 4a becomes large. Therefore, it is preferable that the difference in refractive index between the lens layer 4 and the transparent resin layer 5 is large.

In this solid-state image pickup device, a spacer for securing a space between the phase grating and the image plane, or an adhesive for fixing the phase grating and the spacer to the sensor portion, as in the case of attaching the phase grating later. It is a configuration that does not require the like. Further, in order to produce the transparent resin layer 5 and the lattice-shaped layer 6,
Almost the same process as the process for processing the microlens 4a of the lens layer 4 can be used, and it is not necessary to introduce new equipment.

FIG. 2 shows the lens layer 4 of the second embodiment of the present invention.
6 is a partially cutaway front view showing a part of a solid-state image sensor with an optical low-pass filter in the case of a combination in which the difference in refractive index between the transparent resin layer 5 and the transparent resin layer 5 is small.

In the first embodiment, when the difference in refractive index between the microlens 4a and the transparent resin layer 5 is small, it is necessary to increase the height of the microlens 4a. Indicates. The same parts as those in the first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

FIG. 2A shows a lens shape when the difference in refractive index between the lens layer 4 and the transparent resin layer 5 is small and the element portion 1 and the lens layer 4 are relatively close to each other as in the conventional solid-state image pickup device. FIG. 4 is a partially cutaway front view showing an example of a solid-state image pickup device having a hemispherical shape with a small radius of curvature and a large curvature. Figure 2
In (b), an intervening layer 7 made of a transparent resin is formed between the lens layer 4 and the element portion 1 so that the apparent and actual distances from the lens layer 4 to the element portion 1 are set larger than in the conventional case. FIG. 6 is a partially cutaway front view showing an example of a solid-state imaging device capable of making the curvature of a microlens 4a relatively small.

The solid-state image pickup device with an optical low-pass filter shown in FIG. 2A has an element portion 1 having light receiving portions 3, 3, 3, ... And microlenses 14a, 14a, 14.
It is composed of a lens layer 4 having a, ..., A transparent resin layer 5, and an uneven grid-shaped layer 6.

In the solid-state image sensor of this embodiment, the lens layer 4
The hemispherical microlenses 14a, 14a, 14
It is formed of a, ..., And the lens substrate 14b. The surface portions of the microlenses 14a, 14a, 14a, ... Are filled with the filling resin layer 5a, and the main body layer 5b is continuously provided. In this example, the intervening layer is the microlens 14a.
There is no choice but to use the circular arc portion 14c. However, it is difficult to manufacture the lens in the shape of a ball with a large curvature, and there is a limit.

The solid-state image pickup device with an optical low-pass filter shown in FIG. 2 (b) is a lens having an element section 1 having light receiving sections 3, 3, 3, ... And microlenses 4a, 4a, 4a. It is composed of a layer 4, a transparent resin layer 5, an uneven lattice-shaped layer 6, and an intervening layer 7 provided between the element portion 1 and the lens layer 4. By adding the intervening layer 7 in this way, it is possible to cope with the case where the focal length of the microlens 4a is long. That is, since the curvature of the microlens 4a can be reduced, the height of the lens can be easily formed.

In this embodiment, the material of the intervening layer 7 may be the same as the material of the microlens as in the conventional case, or another transparent resin material may be used. Since this solid-state image pickup device can have a relatively large radius of curvature and the lens layer 4 and the element portion 1 can be integrated by the intervening layer 7, the assembly is further facilitated and the cost can be reduced.

FIG. 3 is a partially cutaway front view showing a part of a solid-state image pickup device with an optical low-pass filter for color according to the third embodiment of the present invention. The solid-state imaging device according to the present embodiment includes an element part 1 having light receiving parts 3, 3, 3, ..., A lens layer 4 having microlenses 4a, 4a, 4a ,. It is composed of a lattice-shaped layer 6 having a shape and a color filter layer 8 provided on the upper portion of the element portion 1.

This solid-state image pickup device includes the respective receiving portions 3, 3,
3, ... Color filters 9, 9 for performing color separation for each surface
The only difference from the first embodiment is that points 9 and 9 are provided. In addition, like the solid-state image sensor with the optical low-pass filter of the first embodiment, the microlens 4 is used.
It is composed of a lens layer 4 having a, a transparent resin layer 5, and a concavo-convex lattice-shaped layer 6.

The color filter layer 8 is formed by embedding at least one color filter 9 in the resin layer 8a corresponding to each light receiving portion 3. The color filter 9 has a feature of transmitting wavelengths in the wavelength bands such as Cy (cyan color), Ye (yellow), Mg (magenta), and G (green), for example.

This solid-state image pickup device has a spacer for securing a space between the phase grating and the image plane, and an adhesive for fixing the phase grating and the spacer to the sensor portion, as in the case of attaching the phase grating later. It is a configuration that does not require the like. Further, in order to produce the transparent resin layer 5 and the lattice-shaped layer 6,
Since a process substantially similar to the process for processing the microlens 4a of the lens layer 4 can be used, a new
There is no need to install equipment.

FIG. 4 is a partially cutaway front view showing a part of a solid-state image pickup device with an optical low pass filter according to a fourth embodiment of the present invention. The solid-state image sensor of this embodiment includes the light receiving unit 3,
The element portion 1 having 3, 3, ..., The lens layer 4 having the microlenses, the transparent resin layer 5, the concave and convex lattice-shaped layer 6, and the color filter layer 8 provided on the element portion 1.
It consists of and. This solid-state image sensor has the color filters 9, 9, 9 for performing color separation for each of the light-receiving units 3, 3, 3, ..., In that the solid-state image sensor of the second embodiment shown in FIG. Different from the image sensor. Further, in the solid-state imaging device of the present embodiment, in the third embodiment, when the difference in refractive index between the microlens and the transparent resin layer 5 is small, it is necessary to increase the height of the microlens. It is different from the solid-state image sensor of the third embodiment shown in FIG. 3 in that it is formed in this way. The same parts as those in the above-mentioned respective embodiments are designated by the same reference numerals, and detailed description thereof will be omitted.

FIG. 4A shows the lens shape when the difference in refractive index between the lens layer 4 and the transparent resin layer 5 is small and the element section 1 and the lens layer 4 are relatively close to each other as in the conventional solid-state image pickup device. FIG. 3 is a partially cutaway front view showing a solid-state imaging device for a color that is formed into a substantially hemispherical shape and has a small radius of curvature. In FIG. 4B, an intervening layer 7 made of a transparent resin is formed between the lens layer 4 and the element portion 1 so that the apparent and actual distances from the lens layer 4 to the element portion 1 are made larger than in the conventional case. FIG. 6 is a partially cutaway front view showing a part of a solid-state color image pickup device in which the curvature of the microlenses of the lens layer 4 is made small to facilitate workability.

The solid-state image pickup device with an optical low-pass filter shown in FIG. 4A has color filters 9, 9, 9, for performing color separation for each of the receiving portions 3, 3, 3 ,. The color filter layer 8 is provided between the element portion 1 and the lens layer 4, and the ball-shaped microlens 14a and the lens substrate 14 are provided.
The lens layer 4 is formed from b. A transparent resin layer 5 and a lattice-shaped layer 6 are sequentially provided on the lens layer 4.

In the solid-state image sensor of this example, the lens layer 4 is formed of the ball-shaped microlenses 14a and the lens substrate 14b. The transparent resin layer 5 is formed by filling the surface portions of the microlenses 14a, 14a, 14a, ... With a filling resin layer 5a and closely adhering to the main body layer 5b. In this example, the microlens 14a has a large curvature, which makes processing difficult. Since the other points are the same as those in the embodiment shown in FIG.

The solid-state image pickup device with an optical low-pass filter shown in FIG. 4B has color filters 9, 9, 9, for color separation for each of the receiving portions 3, 3, 3 ,. The color filter layer 8 is provided on the element portion 1, and the intervening layer 7 is provided between the color filter layer 8 and the lens layer 4. A transparent resin layer 5 and a lattice-shaped layer 6 are formed on the lens layer 4.
Are provided in sequence. Since the other points are the same as those in the embodiment shown in FIG.

In this solid-state image pickup device, the radius of curvature can be made relatively large, and the lens layer 4 and the element portion 1 are interposed by the intervening layer 7.
Since they can be integrated with each other, the assembling becomes easier and the cost can be reduced.

The solid-state image pickup device according to the above-mentioned embodiment of the present invention can be more specifically satisfied with the following conditional expression. When the transparent resin layer 5 is not added to the lens layer 4, that is, when the lens layer is exposed in the air, the distance from the lens layer 4 to the light receiving surface of the light receiving unit 3 when converted into air (microlens) 4a, 14a
When the required distance in the air without a resin layer from the bottom surface to the light receiving portion 3 is taken into consideration in consideration of the refractive index and the refractive index of air is set to 1) Lo, and the lens layer 4 is covered with the transparent resin layer 5. The required distance when converted to the distance in air from the lens layer 4 to the light receiving surface of the light receiving unit 3 (the micro lens 4
a, 14a) and the required thickness of the resin layer 11 from the bottom surface to the light receiving portion 3 when the refractive index of air is converted to 1) is L
When u, the refractive index of the transparent resin of the transparent resin layer 5 is ndu, and the refractive index of the material of the lens layer 4 is ndo, the conditions under which the effect of the microlens 4a is substantially the same before and after covering with the transparent resin layer 5 are as follows. It is shown by the equation (1).

1- (ndo-ndu) / (ndo-1) <Lo · (ndo-1) / {Lu · (ndo-ndu)} <1+ (ndo-ndu) / (ndo-1) (1) When the lens layer 4 is covered with the transparent resin layer 5 having a refractive index ndo as in the above formula, the range that exists in the relationship caused by the presence or absence of the transparent resin layer 5 is due to the addition of the transparent resin layer 5. This is because the focal length of the lens is long and the depth of focus is long.

Further, the transparent resin layer 5 on the lens layer 4 is provided.
The material of the transparent resin intervening layer 7 below the lens layer 4 is a transparent resin material, and the material used for the transparent resin layer 5 above the lens layer 4 is more than the material forming the lens layer 4. Also, it is desirable that it has a low refractive index, has a low viscosity that easily flows into the gaps of the microlenses 4a before curing, and has sufficient strength after curing. For example, resin layer 1
1 is an acrylic resin, and the lens layer 4 is an acrylic resin,
By using a polyvinyl alcohol-based resin for the transparent resin layer 5 and an acrylic resin for the phase grating portion 6, the phase grating can be integrally formed on a solid-state imaging device having a microlens, and the curvature of the microlens can be easily processed. Could be in range.

The material of the projections 6a forming the grating-shaped layer 6 having an uneven shape on the transparent resin layer 5 in order to obtain the effect of the phase grating may be the same as the material of the transparent resin layer 5, or the microlens. It may be the same as the material of the lens layer 4 having 4a, or may be a completely different transparent resin material. However, it is preferably a photosensitive resin for producing an uneven shape, and more preferably, a shape can be rounded by heating.

Further, the transparent resin layer 5 or the intervening layer 7 is used.
By using an infrared-absorbing resin material as the material, the optical system can be further simplified. FIG. 6 is a configuration diagram showing a schematic configuration of an embodiment of a video camera using a solid-state image pickup device with an optical low-pass filter of the present invention in a zoom lens system.

In FIG. 6, reference numeral 30 is a solid-state image pickup device with an optical low-pass filter according to the embodiment of the present invention, 31 is a zoom lens, and 32 is an infrared cut filter. A crystal filter as an optical low-pass filter as in the past is not necessary. It goes without saying that the video camera of this embodiment can have the same structure as the conventional one. By using the solid-state image pickup device with optical low-pass filters of the first to fourth embodiments as the solid-state image pickup device with optical low-pass filter of the present embodiment, the object of the image pickup device in the lens system of the conventional video camera is used. The space for the quartz low-pass filter arranged on the side can be shortened by 4 to 7 mm.

Further, assuming that the solid-state image pickup device with an optical low-pass filter of the above embodiment uses an infrared absorbing resin material for the transparent resin layer 5 or the intervening layer 7, the infrared cut filter 32 in FIG. 6 is omitted. In addition, the optical system can be shortened by 1.0 to 1.3 mm.

As a method of omitting the space for the infrared cut filter, it may be used for the sealing glass of the solid-state image pickup device. FIG. 7 is a configuration diagram showing a schematic configuration showing another embodiment in which a video camera is configured using the optical low pass filter of the present invention. Reference numeral 40 is a solid-state image pickup device with an optical low-pass filter including an infrared cut effect, 41 is a lens system, an output signal from the solid-state image pickup device 40 is processed by a signal processing system 42, and a viewfinder 43 or a recording system 44. Transfer the signal to. The configuration of the present embodiment is a basic configuration, and it is needless to say that a more complete video camera can be configured by adding additional functions.

Further, in this embodiment, since the distance from the lens layer to the light receiving portion is long and the aperture of the lens of the microlens is small, there are cases in which light rays that cannot be incident on the light receiving portion pass through the microlens. Therefore, as a structure that guides light rays to each light receiving portion without loss, a structure having a high reflectance shield up to the lens layer or a position close to the lens layer is provided for each light receiving portion to prevent light rays from leaking out of the light receiving portion. By taking, it is possible to substantially increase the numerical aperture of the microlens. Alternatively, instead of a shield having a high reflectance, a structure having a refractive index distribution may be used to guide the light rays to the light receiving section.

[0062]

As described above, since the solid-state image pickup device with an optical low-pass filter of the present invention can be manufactured by the same method as the process of manufacturing a microlens, an optical low-pass filter with a phase grating can be manufactured. The alignment accuracy between the phase grating and the light receiving portion can be increased, and the manufacturing can be performed at low cost.

A video camera using an optical system comprising a solid-state image pickup device with an optical low-pass filter according to the present invention,
A compact structure that does not require a special space for a crystal filter or the like can be obtained.

[Brief description of drawings]

FIG. 1 is a partially cutaway front view illustrating a first embodiment of a solid-state image sensor with an optical low-pass filter according to the present invention.

FIG. 2 shows the distance between the lens layer and the light receiving portion when the difference in refractive index between the microlenses and the transparent material covering the microlenses in the second embodiment of the solid-state imaging device with the optical low-pass filter of the present invention is small. FIG. 3 is a partially cutaway front view showing an example of lengthening, FIG. 3A is a partially cutaway front view showing an example of forming a microlens in a ball shape, and FIG. 3B is a partially cutaway front view showing an example of using a transparent resin material. Is.

FIG. 3 is a partially cutaway front view illustrating a third embodiment having a color filter of a solid-state imaging device with an optical low-pass filter according to the present invention.

FIG. 4 is an optical low-pass filter according to a fourth embodiment of the present invention having a color filter of a solid-state image sensor, in which the lens layer and the light-receiving surface of the microlens and the transparent material covering the microlens have a small difference in refractive index. FIG. 2 is a partially cutaway front view showing an example of increasing the distance, (a) is a partially cutaway front view showing an example of forming a microlens in a ball shape, and (b) is a partially cutaway view showing an example of using a transparent resin material. It is a front view.

FIG. 5 is a schematic configuration diagram illustrating one example of a lens when the solid-state image sensor with an optical low-pass filter of the present invention is used.

FIG. 6 is a schematic configuration diagram illustrating one embodiment of a video camera using a lens incorporating a solid-state image sensor with an optical low-pass filter of the present invention.

FIG. 7 is a cross-sectional view of a schematic configuration illustrating an image pickup element in which a conventional phase grating filter is integrated.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Element part 2 Semiconductor substrate 3 Light receiving part 4 Lens layer 4a Micro lens 5 Transparent resin layer 5a Filling resin layer 5b Main body layer 6 Lattice-shaped layer 6a Protrusion 7 Intervening layer 8 Color filter layer 9 Color filter 11 Gap layer 14a Micro lens

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location H04N 5/335 V

Claims (11)

[Claims] 1. An element section for receiving incident light and performing photoelectric conversion,
A solid-state imaging device comprising a lens layer having a microlens on an upper part of the element part, the transparent being filled with a transparent resin having a refractive index lower than a refractive index of a material of the lens layer from a surface of the lens layer. A solid-state imaging device with an optical low-pass filter, comprising a resin layer, and a lattice-shaped layer having an uneven shape provided on the transparent resin layer. 2. A plurality of light receiving portions that generate electric charges by the light received by the element portion and a transfer portion that transfers the electric charges generated in each light receiving portion are formed on a semiconductor substrate, and the lens layer is formed. 2. The solid-state imaging device with an optical low-pass filter according to claim 1, wherein the lens layer is provided on an upper portion of the element portion, and the lens layer is configured to collect the incident light on the light receiving portion for each region corresponding to each light receiving portion. 3. A color filter layer is provided on the element section, and the lens layer located above the color filter layer collects incident light to the light receiving section in each region corresponding to each light receiving section. The solid-state imaging device with an optical low-pass filter according to claim 1, configured as described above. 4. An element section for receiving incident light and performing photoelectric conversion,
A solid-state imaging device comprising a lens layer having a microlens on an upper part of the element part, wherein an intervening layer made of a transparent resin material is provided between the lens layer and the element part, and the lens is formed from the surface of the lens layer. A transparent resin material having a refractive index lower than that of the layer material is embedded to form a transparent resin layer, and a transparent resin layer is provided with a lattice-shaped layer having an uneven shape made of transparent resin. Solid-state image sensor with optical low-pass filter. 5. The intervening layer between the lens layer and the element portion is formed of the material of the dome-shaped portion of the microlens, and the microlens collects incident light to the light receiving portion at each light receiving portion. The solid-state image sensor with an optical low-pass filter according to claim 4, wherein the solid-state image sensor is formed so as to be performed for each corresponding region. 6. The solid-state image pickup device with an optical low-pass filter according to claim 4, wherein a color filter layer is provided between the element portion and the lens layer. 7. The refractive index of the microlens is ndo,
The refractive index of the transparent resin of the transparent resin layer that fills the microlens is ndu, and the distance from the lens when the microlens is not filled with the transparent resin to the light receiving surface of the element portion when converted into air is Lo, Refractive index n
Lu is the required distance from the lens when filled with du transparent resin to the light receiving surface of the element section when converted into air.
Where, the relationship between the refractive index and the distance between the transparent resin layer, the microlens, and the light receiving surface of the optical low-pass filter is expressed by the following formula: 1- (ndo-ndu) / (ndo-1) <Lo. (N
do-1) / {Lu · (ndo-ndu)} <1+ (n
The solid-state image sensor with an optical low-pass filter according to claim 1, which satisfies do-ndu) / (ndo-1). 8. The solid-state imaging device with an optical low-pass filter according to claim 1, wherein the transparent resin layer filling the lens layer has infrared absorption properties. 9. The solid-state imaging device with an optical low-pass filter according to claim 4, wherein the intervening layer provided under the lens layer has infrared absorption properties. 10. A video camera comprising a solid-state image pickup device and a lens system, wherein the solid-state image pickup device is the solid-state image pickup device with an optical low-pass filter according to any one of claims 1, 2, 3 or 8. Is a video camera. 11. A video camera comprising a solid-state image sensor and a lens system, wherein the solid-state image sensor is the solid-state image sensor with an optical low-pass filter according to any one of claims 4 to 6. .