CN112180487A

CN112180487A - Camera module and electronic device

Info

Publication number: CN112180487A
Application number: CN202010606869.6A
Authority: CN
Inventors: 岸田宽之; 一户大吾
Original assignee: JSR Corp
Current assignee: JSR Corp
Priority date: 2019-07-03
Filing date: 2020-06-29
Publication date: 2021-01-05
Also published as: JP2021009271A

Abstract

The invention provides a camera module and an electronic device, which can achieve an optical filter capable of achieving both flare suppression, color shading suppression and ghost suppression of a camera image at a high level. The camera module includes: an optical lens group disposed on the incident side of light; an imaging element that receives light incident through the optical lens group; a near-infrared light reflection unit that reflects light in a near-infrared region; and a near-infrared light absorbing portion that absorbs light in the near-infrared region. The near-infrared light absorbing portion includes a cycloolefin resin having a refractive index of 1.52 or more and less than 1.54, and a compound that absorbs near-infrared light.

Description

Camera module and electronic device

Technical Field

One embodiment of the present invention relates to an optical structure of a camera module and an electronic apparatus using the camera module.

Background

In electronic devices such as video cameras, digital still cameras, and mobile phones with camera functions, Charge Coupled Devices (CCDs) or Complementary Metal Oxide Semiconductor (CMOS) image sensors are used as solid-state image sensors that can capture color images. These solid-state imaging elements use silicon photodiodes (silicon photodiodes) having sensitivity to near infrared rays that cannot be perceived by human eyes as light-receiving portions thereof. Since the silicon photodiode has photosensitivity in a region up to the near-infrared wavelength region, it is necessary to perform a sensitivity correction that shows natural color as viewed by human eyes and to use an optical filter (for example, a near-infrared cut filter) that selectively transmits or cuts light in a specific wavelength region in the solid-state imaging device in many cases.

As the near infrared ray cut filter, filters manufactured by various methods have been used since the past. For example, a near-infrared cut filter is known which uses a transparent resin as a base material and contains a near-infrared absorbing dye in the transparent resin (for example, see patent document 1). However, the near-infrared cut filter described in patent document 1 may not have sufficient near-infrared absorption characteristics.

Patent document 2 discloses a near-infrared cut filter having both a wide viewing angle and a high visible light transmittance. Patent document 3 discloses a near infrared cut filter that uses a phthalocyanine-based dye having a specific structure to achieve both excellent visible transmittance and a long wavelength absorption maximum wavelength at a high level. However, the near-infrared cut-off filters described in patent documents 2 and 3 use a substrate having an absorption band with sufficient intensity in the vicinity of a wavelength of 700nm, but hardly having absorption in the near-infrared wavelength region of, for example, 900nm to 1200 nm. Therefore, in such a configuration, light in the near infrared wavelength region is almost cut off only by reflection of the dielectric multilayer film, and some stray light due to internal reflection in the optical filter or reflection between the optical filter and the lens may cause ghost or flare when imaging is performed in a dark environment. In particular, in recent years, even in mobile devices such as smartphones, high image quality of cameras is strongly required, and there are cases where conventional optical filters cannot be used appropriately.

On the other hand, as an optical filter using a base material having a broad absorption in the near infrared wavelength region, an infrared blocking filter as disclosed in patent document 4 is proposed. Patent document 4 discloses that a compound mainly having a dithiolene structure is used to achieve broad absorption in the near-infrared wavelength range, but the absorption intensity near 700nm is not sufficient.

Patent document 5 discloses a camera module in which a cover glass having a characteristic of reflecting light in a specific wavelength band by a dielectric multilayer film and a near-infrared light absorbing portion are combined. However, the camera module of patent document 5 has an effect of suppressing near infrared rays transmitted through the cover glass, but when imaging is performed under a light source of near infrared light intensity, incident near infrared rays are reflected on the surface of the near infrared light absorbing portion and are again reflected on the cover glass, and ghost images caused by the above-described phenomenon become a problem.

[ Prior art documents ]

[ patent document ]

[ patent document 1] Japanese patent laid-open No. Hei 6-200113

[ patent document 2] Japanese patent application laid-open No. 2011-100084

[ patent document 3] International publication No. 2015/025779 Manual

[ patent document 4] International publication No. 2014/168190 Manual

[ patent document 5] International publication No. 2018/155634 Manual

Disclosure of Invention

[ problems to be solved by the invention ]

In addition to the above-described problems, in order to further improve the performance of the camera module, functions of a conventional optical filter in which absorption by a dye and reflection by a dielectric multilayer film are combined by different members for each function have been studied, and there is a demand for an optical filter that can also cope with such a configuration.

An object of one embodiment of the present invention is to provide a camera module having an optical filter that can achieve both of flare suppression and color shading suppression and ghost suppression of a camera image, which cannot be sufficiently achieved by a conventional optical filter, at a high level.

[ means for solving problems ]

A camera module according to an embodiment of the present invention includes: an optical lens group disposed on the incident side of light; an imaging element that receives light incident through the optical lens group; a cover glass having a near-infrared light reflecting section that reflects light in a near-infrared region; and a near-infrared light absorbing portion that absorbs light in the near-infrared region. The near-infrared light absorbing portion includes a cycloolefin resin having a refractive index of 1.52 or more and less than 1.54 and a compound that absorbs near-infrared light.

The near-infrared light reflecting portion and the near-infrared light absorbing portion may be arranged in this order from the light incident side. The near-infrared light reflecting portion may include: a glass substrate; an anti-reflection layer located on at least one side of the glass substrate and preventing reflection of light in a visible region; and a reflective layer reflecting light in a near infrared region. The near infrared absorber can disperse the compound in the cyclic olefin resin. The near-infrared light absorbing portion may have an antireflection layer on the light incident surface to prevent reflection of light in the visible light region.

The camera module according to an embodiment of the present invention preferably satisfies the following conditions (1) and (2).

Condition (1) R_NIR-5＜30

Condition (2) R_NIR-30＜30

Here, the number of the first and second electrodes,

[ numerical formula 1]

RA5(λ): reflectance at wavelength λ nm when incident light enters the optical filter at 5 degrees from the optical lens group side

RB5(λ): a reflectance at a wavelength of λ nm when the light is incident on the cover glass at 5 degrees from the optical lens group side,

[ numerical formula 2]

RA30(λ): reflectance at wavelength λ nm when incident from the optical lens group side at 30 degrees to the optical filter

RB30(λ): a reflectance at a wavelength λ nm when the light is incident on the cover glass at 30 degrees from the optical lens group side.

The camera module according to an embodiment of the present invention preferably further satisfies the following conditions (3) and (4).

Condition (3) T_NIR-5＜30

Condition (4) T_NIR-30＜30

Here, the number of the first and second electrodes,

[ numerical formula 3]

TA5(λ): transmittance at wavelength of λ nm when incident light enters the optical filter at 5 degrees from the optical lens group side

TB5(λ): transmittance at wavelength of λ nm when incident on the cover glass at 5 degrees from the side opposite to the optical lens group

[ numerical formula 4]

TA30(λ): transmittance at wavelength λ nm when incident light enters the optical filter from the optical lens group side at 30 degrees

TB30(λ): transmittance at wavelength λ nm when incident on the cover glass at 30 degrees from the side opposite to the optical lens group side.

The near-infrared ray absorbing compound may be at least one compound selected from the group consisting of squarylium compounds, phthalocyanine compounds, naphthalocyanine compounds, ketanium compounds, and cyanine compounds.

The optical filter preferably has a maximum absorption wavelength in a wavelength region of 650nm to 800 nm. The optical filter contains a compound having an absorption maximum wavelength in a region of a wavelength of 650nm or more and 715nm or less, the compound is preferably a squarylium-based compound, a compound having an absorption maximum wavelength in a region of a wavelength of more than 715nm and 750nm or less is preferably a phthalocyanine-based compound, and a compound having an absorption maximum wavelength in a region of a wavelength of more than 750nm and 800nm or less is preferably a squarylium-based compound.

[ Effect of the invention ]

According to one embodiment of the present invention, a camera module having excellent near infrared ray cutoff characteristics, small incident angle dependency, and excellent transmittance characteristics in the visible wavelength region, flare suppression effect, color shading suppression effect, and ghost suppression effect can be provided.

Drawings

Fig. 1 is a diagram showing a configuration for measuring a transmission spectrum from a vertical direction and a direction inclined by 30 degrees, and a configuration for measuring a reflection spectrum from a direction inclined by 5 degrees and a direction inclined by 30 degrees.

Fig. 2 is a schematic diagram showing the configuration of a camera module used for flare evaluation, color shading evaluation, and ghost evaluation in examples and comparative examples.

Fig. 3 is a diagram illustrating a mechanism of generating ghosting in the camera module.

Fig. 4 is a schematic diagram for explaining color shading evaluation of camera images performed in examples and comparative examples.

Fig. 5 is a schematic diagram for explaining flare evaluation of camera images performed in examples and comparative examples.

Fig. 6 is a schematic diagram for explaining ghost evaluation of camera images performed in examples and comparative examples.

Fig. 7 is a spectral transmission-reflection spectrum of the optical filter obtained in example 1.

Fig. 8 is a spectral transmission-reflection spectrum of the optical filter obtained in example 2.

Fig. 9 is a spectral transmission-reflection spectrum of the optical filter obtained in example 3.

Fig. 10 is a spectral transmission-reflection spectrum of the optical filter obtained in example 4.

Fig. 11 is a spectral transmission-reflection spectrum of the optical filter obtained in example 5.

Fig. 12 is a spectral transmission-reflection spectrum of the optical filter obtained in example 6.

Fig. 13 is a spectral transmission-reflection spectrum of the optical filter obtained in example 7.

Fig. 14 is a spectral transmission-reflection spectrum of the optical filter obtained in example 8.

Fig. 15 is a spectral transmission-reflection spectrum of the optical filter obtained in example 10.

Fig. 16 is a spectral transmission-reflection spectrum of the optical filter obtained in example 11.

Fig. 17 is a spectral transmission-reflection spectrum of the optical filter obtained in comparative example 1.

Fig. 18 is a spectral transmission-reflection spectrum of the optical filter obtained in comparative example 2.

Fig. 19 is a spectral transmission-reflection spectrum of the optical filter obtained in comparative example 3.

Fig. 20 is a diagram showing a configuration of a camera module according to an embodiment of the present invention.

Fig. 21 is a diagram showing a structure of a cover glass according to an embodiment of the present invention.

Fig. 22 is a diagram showing a configuration of an optical filter according to an embodiment of the present invention.

Fig. 23 is a diagram showing a configuration of an image pickup device according to an embodiment of the present invention.

Description of the symbols

1: optical filter

2. 2': light (es)

3: spectrophotometer

21. 23: direct light

22. 24: scattering incident light

100: camera module

102: frame body

103: shell body

104: optical lens group

106: image pickup device

109: cover glass

111: optical filter

112: transparent resin base material

114: anti-reflection layer (NIR)

116: transparent substrate

118: transparent resin layer

120: transparent substrate

122: anti-reflection layer

124: reflective layer

126: pixel

128: light emitting diode

130: color filter layer

132: microlens array

134: wiring layer

200: camera image

202: white board

204: example of the center portion of the white plate

206: examples of the end of the white plate

208: camera image

210: light source

212: examples of spots around the light source

214: camera image

216: light source/halogen lamp light source

218: example of ghost around light Source

Detailed Description

Embodiments of the present invention will be described with reference to the drawings and the like. The present invention can be embodied in a wide variety of forms, and is not limited to the description of the embodiments illustrated below. In the drawings, the width, thickness, shape, and the like of each part are schematically shown as compared with the actual form in order to make the description more clear, and the present invention is not limited to the explanation thereof. In the present specification and the drawings, the same or similar elements as those described with respect to the already-shown drawings are denoted by the same reference numerals (only the reference numerals a, b, etc. are denoted by the reference numerals after the reference numerals), and detailed description thereof may be omitted as appropriate.

Hereinafter, an optical filter, a camera module using the optical filter, and an electronic device having the camera module according to an embodiment of the present invention will be described in detail.

1. Camera module

The camera module 100 according to an embodiment of the present invention includes a near-infrared light reflecting portion and a near-infrared light absorbing portion in addition to the optical lens group 104 and the image pickup element 106. The structure of the camera module 100 will be described below with reference to fig. 20.

1-1. construction of camera Module

Fig. 20 shows a configuration of a camera module 100 according to an embodiment of the present invention. The camera module 100 includes: an optical lens group 104; a housing 102 that houses the optical lens group 104; an imaging element 106 provided on the opposite side of the optical lens group 104 from the light incident side; a near-infrared light absorbing portion provided between the optical lens group 104 and the image pickup element 106; and a near-infrared light reflecting section provided in front of the incident surface of the optical lens group 104. The housing 102, the optical filter 111, and the image pickup element 106 are housed in a case (casting) 103 or supported by the case 103. The camera module 100 has a configuration in which a near-infrared light reflecting portion, an optical lens group 104, a near-infrared light absorbing portion, and an imaging element 106 are arranged from the incident side of external light. The near-infrared light reflecting portion and the near-infrared light absorbing portion are disposed so as to cover at least a part of, preferably the entire surface of, the light receiving surface of the imaging element 106 when the imaging element 106 is viewed from the light incident side. The camera module 100 is configured such that stray light is not incident on the imaging element 106 from the outside through the housing 102 or the case 103.

The configuration of the optical lens group 104 shown in fig. 20 is an example, and an embodiment of the present invention is not limited to the configuration of the lens shown in the drawings. Although not shown in fig. 20, a driving mechanism for zooming the lens may be added to the camera module 100.

1-2. constitution of near-infrared light reflecting part

The near-infrared light reflecting section includes an optical film that reflects light in the near-infrared region. The near-infrared light reflecting portion is configured to include an optical film that prevents reflection of light in a visible wavelength region. The near-infrared light reflecting section has a structure in which these optical films are provided on a light-transmitting substrate. The near-infrared light reflecting section functions as a cover glass provided on the light incident side of the camera module 100, for example.

Fig. 21 shows a structure of a cover glass 109 having a function as a near-infrared light reflecting section of the camera module 100 according to an embodiment of the present invention. Fig. 21 (a) shows a cover glass 109a in which an antireflection layer 122 for preventing reflection of light in the visible wavelength region, a reflection layer 124 for reflecting near-infrared light, and an antireflection layer 114 having an antireflection effect on light having a wavelength of 700nm to 1200nm are provided on a transparent substrate 120. In the cover glass 109a, the antireflection layer 122, the reflection layer 124, the transparent substrate 120, and the antireflection layer 114 are disposed in this order from the light incident side. Namely, the device has the following structure: on a surface of the transparent substrate 120 on a side on which external light is incident, an antireflection layer 122 and a reflection layer 124 are provided, and on a surface on an opposite side to the surface, an antireflection layer 114 is provided. The antireflection layer 122 that prevents reflection of light in the visible light wavelength region and the reflection layer 124 that reflects near-infrared light are formed of dielectric multilayer films, respectively. The transparent substrate 120 is made of crystallized glass, for example, in order to increase the transmittance of visible light. Further, an anti-fouling layer for preventing fouling may be provided on the surface of the anti-reflection layer 122 of the cover glass 109 a.

The cover glass 109B shown in fig. 21 (B) differs from the cover glass 109a in that a reflective layer 124 that reflects near-infrared light is provided between the transparent substrate 120 and the antireflection layer 114, but the same members as the cover glass 109a shown in fig. 21 (a) are used for each member that constitutes the cover glass. The cover glass 109a and the cover glass 109b suppress surface reflection of incident external light by the action of the antireflection layer 122, and further reflect near-infrared light in the external light component by the action of the reflection layer 124. In addition, the light in the visible light wavelength region incident from the back surfaces (the surfaces on the opposite sides to the light incident sides) of the

cover glasses

109a and 109b is suppressed from being reflected on the surface of the transparent substrate 120 by the antireflection layer 114.

1-3. construction of near infrared light absorbing part

The near-infrared light absorbing section is configured to include a transparent resin layer containing a compound that absorbs light in the near-infrared region. The near-infrared light absorbing portion is configured to include an optical film that prevents reflection of light in a visible wavelength region. The near-infrared light absorbing section has a structure in which these members are provided on a light-transmitting base material. The near-infrared light absorbing portion realizes its function by an optical filter provided to the camera module 100, for example.

Fig. 22 shows a configuration of an optical filter 111 having a function as a near-infrared light absorbing portion of the camera module 100 according to the embodiment of the present invention. Fig. 22 (a) shows an optical filter 111a having: a transparent resin substrate 112 containing a near infrared ray absorbing compound, and an antireflection layer 114 having an antireflection effect on light having a wavelength of 700nm to 1200 nm. The transparent resin base 112 is formed in a flat plate shape, and a near infrared ray absorbing compound is dispersed and contained in the transparent resin base 112. The antireflection layer 114 is provided on the light incident side surface of the transparent resin substrate 112. The near-infrared light incident on the optical filter 111a is incident on the transparent resin substrate 112 with almost no reflection by the effect of the antireflection layer 114, and is absorbed in the transparent resin substrate 112. On the other hand, the transparent resin substrate 112 has a characteristic of hardly absorbing light in the visible light wavelength region and transmitting it. Thus, the optical filter 111a has a characteristic of transmitting light in the visible wavelength region and absorbing near-infrared light without scattering the near-infrared light.

Fig. 22 (B) shows an optical filter 111B having: a transparent substrate 116 made of glass or the like, a transparent resin layer 118 containing a compound that absorbs near infrared rays, and an antireflection layer 114 having an antireflection effect on light having a wavelength of 700nm to 1200 nm. The transparent resin layer 118 is provided on the light incident side surface of the transparent substrate 116. Further, the antireflection layer 114 is provided on the surface of the transparent resin layer 118 on the light incident side. Fig. 22 (C) shows an optical filter 111C having a structure in which a transparent resin layer 118 containing a near-infrared ray absorbing compound is provided on the surface of the transparent substrate 116 opposite to the light incident surface. The antireflection layer 114 having an antireflection effect on light having a wavelength of 700nm to 1200nm is directly provided on the light incident side surface of the transparent substrate 116. The optical filter 111B shown in fig. 22 (B) and the optical filter 111C shown in fig. 22 (C) include the transparent base material 116, but have a characteristic of transmitting light in the visible light wavelength region and absorbing near infrared light without scattering the near infrared light by the action of the transparent resin layer 118 and the antireflection layer 114, compared to the optical filter 111a shown in fig. 22 (a).

The transparent resin substrate 112 and the transparent resin layer 118 are preferably cycloolefin resins having a refractive index of 1.52 or more and less than 1.54. The transparent substrate 116 may be made of a general optical glass. Typical optical glasses include: BK7 (refractive index 1.52, manufactured by Schottky (SCHOTT) corporation) or D263 (refractive index 1.52, manufactured by Schottky (SCHOTT) corporation).

When a refractive index difference is generated between two components of the interface, reflected light is generated according to Fresnel (Fresnel) equation. By using the cycloolefin resin having a refractive index in the above range, reflected light of the laminate when the general optical glass is used as a transparent base material can be reduced, and ghost of the obtained image pickup device can be suppressed. The transparent resin substrate 112 and the transparent resin layer 118 are more preferably cycloolefin resins having refractive indices of 1.52 to 1.53. Here, the refractive index as shown here means: using a prism coupler (prism coupler) model 2010 (manufactured by Metricon corporation), a prism coupler was manufactured in accordance with Japanese Industrial Standards (JIS) K7142: 2014, and use width of 8mm and lengthRefractive index n of 20mm and 3mm thick test piece measured at 23 deg.C with 589nm light_D。

1-4. image pickup element

The image pickup element 106 may be implemented by a CMOS image sensor, a CCD image sensor, or the like. These image sensors include a photodiode constituting a pixel, a signal reading circuit, and the like. An example of the image pickup device 106 is shown below.

Fig. 23 shows a cross-sectional structure of a pixel 126 of the image pickup element 106 used in the camera module 100. The pixel 126 includes photodiodes 128(128(R), 128(G), 128(B)) as light receiving elements. A color filter layer 130 and a microlens array 132 are provided on the light receiving surface of the photodiode 128. In addition, when the image pickup device 106 is of a surface-incident type, the wiring layer 134 is provided between the photodiode 128 and the color filter layer 130. The wiring layer 134 is a layer including wirings provided in the pixels 126, such as address lines and signal lines. In the wiring layer 134, a plurality of wirings can be separated by an interlayer insulating film and multilayered. In general, address lines and signal lines extend in the row direction and the column direction and intersect each other, and are provided in different layers with an interlayer insulating film interposed therebetween.

The color filter layer 130 is provided with a red color filter layer 130r, a green color filter layer 130g, and a blue color filter layer 130b so that a color image can be photographed. The color filter layer 130 has a transmission spectrum corresponding to each color, and for example, the red color filter layer 130r has a characteristic of transmitting not only a red light band but also a band up to a near-infrared light band.

The photodiode 128 is formed on a semiconductor substrate. As the semiconductor substrate, for example, a silicon substrate, a substrate in which a silicon layer is provided over an insulating layer (a Silicon On Insulator (SOI) substrate), or the like can be used. The photodiode 128 includes a semiconductor junction based on a pn junction or a pin junction, and converts incident light into an electric signal by a photoelectric effect. The photodiode 128 has photosensitivity over a wide band from visible light to near-infrared light depending on the physical properties of a silicon semiconductor.

As shown in fig. 20, the camera module 100 of the present embodiment includes an optical filter 111 having a function of blocking near infrared rays on the light incident surface side of the image pickup device 106. The optical filter 111 attenuates the near-infrared light transmitted through the optical lens group 104, and contributes to an increase in the dynamic range (dynamic range) of the image pickup device 106. Further, as described later, the optical filter 111 can greatly suppress the influence of ghosting.

2. Conditions that the camera module should satisfy

In the camera module 100, light incident on the light receiving surface of the image pickup element 106 includes direct light and scattered incident light. If the influence of the scattered incident light on the direct light cannot be ignored, the occurrence of a ghost is visually recognized in the image captured by the camera module 100. In this section, first, consideration is given to direct light and scattered incident light that enter the light receiving surface of the image pickup element 106.

2-1. ghost generation mechanism

Fig. 2 shows an example of the configuration of the camera module 100. Fig. 2 (a) shows an optical lens group 104x accommodated in a housing 102x, an optical filter 111x as a near-infrared light absorbing section, and an image pickup device 106 x. Fig. 2 (B) shows a configuration in which a cover glass 109x as a near-infrared light reflecting unit is disposed on the front surface of the optical lens group 104x on the light incident side. Fig. 2 (C) shows a mode in which the optical filter 111x is disposed in the optical lens group 104 x. In fig. 2 (C), the optical filter 111x is located between the 4 th and 5 th pieces of the optical lens group 104x, and may be mounted at another position. From the viewpoint of ease of designing a lens group with little wavelength dispersion, it is preferable to mount the optical filter 111x between the 2 nd and 3 rd pieces, between the 3 rd and 4 th pieces, and between the 4 th and 5 th pieces of the optical lens group 104 x. The optical lens group 104x is used with an incidence Angle of Chief rays (Chief Ray Angle, CRA) allowable by a pixel on a sensor light receiving surface being 30 to 60 degrees.

Fig. 3 shows an example of a mechanism for generating ghosts in the camera module 100x having the configuration shown in fig. 2 (B). Fig. 3 (a) shows an example of ghosts generated due to the following reasons: after the external light passes through the cover glass 109x, the light incident from the optical lens group 104x is reflected on the surface of the optical filter 111x, and the reflected light is incident again on the surface of the cover glass 109x and reflected, and then passes through the optical filter 111x and enters the image pickup device 106 x. Fig. 3 (B) shows a case where the incident angle of the outside light incident on the cover glass 109x is large with respect to fig. 3 (a). When the incident angle of the external light is large, part of the light incident from the optical lens group 104x becomes reflected light on the surface of the optical filter 111x, but the incident angle is large, and therefore the light is reflected in the housing 102x in a complicated manner, and the reflected light is incident again on the surface of the cover glass 109x, is reflected again, and then is transmitted through the optical filter 111x to enter the imaging element 106x, thereby generating a ghost. In particular, in the optical lens group 104x having a CRA of 34 degrees or more, the curvature of the lens is large and complicated reflection tends to occur.

R obtained from the reflectance of light incident from the optical lens group 104x to the cover glass 109x and the reflectance of light incident from the optical lens group 104x to the optical filter 111x_NIR-0And R_NIR-30The ghost generated by the optical path shown in fig. 3 (a) can be effectively reduced by suppressing the ghost to a low level. T obtained from the transmittance of light incident from the optical lens group 104x to the cover glass 109x and the transmittance of light incident from the optical lens group 104x to the optical filter 111x_NIR-0And T_NIR-30The ghost generated by the optical path shown in fig. 3 (B) can be effectively reduced by suppressing the ghost to a low level. In particular, it is preferably used in combination with the optical lens group 104x having a CRA of 34 degrees or more, and more preferably used in combination with the optical lens group 104x having a CRA of 40 degrees or more.

As shown in fig. 3 (a), when the incident angle of light is small, the difference between the position of the direct light 21 and the position of the scattered incident light 22 on the imaging element 106x is small, and the influence of ghost is small. On the other hand, as shown in fig. 3 (B), when the incident angle of light is large, the difference between the position of the direct light 23 and the position of the scattered incident light 24 on the image sensor 106x is large, and the influence of ghost tends to be large. Actually, if the incident angle of the external light is about 5 degrees or more, the influence of the ghost becomes a problem in many cases.

Some camera modules include an optical lens group designed to include an optical path in which the incident angle of light incident on an optical filter is about 35 degrees. It is considered that, when the incident angle to the optical filter is about 35 degrees, the influence of the light reflected on the surface of the optical filter scattering in the housing and being incident again is small, but when the incident angle to the optical filter is about 30 degrees, the occurrence of ghost is often problematic.

2-2 regarding conditions (1) to (4)

In this case, the camera module 100 of the present embodiment satisfies the following conditions (1) to (4), and can capture high-quality images with less ghost images in both the case of low-angle incidence in which the incident angle of external light is 5 degrees and the case of high-angle incidence in which the incident angle is 30 degrees in the environment of near-infrared light intensity.

The conditions (1) and (2) are as follows.

Condition (1) R_NIR-5＜30

Condition (2) R_NIR-30＜30

Here, R_NIR-5Is a value represented by the following formula.

[ numerical formula 1]

RA5(λ): a reflectance at a wavelength of λ nm when the light is incident on the optical filter at 5 degrees from the optical lens group side,

RB5(λ): a reflectance at wavelength λ nm when the light is incident on the cover glass at 5 degrees from the optical lens group side.

In addition, R_NIR-30Is a value represented by the following formula.

[ numerical formula 2]

The conditions (3) and (4) are as follows.

Condition (3) T_NIR-5＜30

Condition (4) T_NIR-30＜30

Here, T_NIR-5Is a value represented by the following formula.

[ numerical formula 3]

TA5(λ): a transmittance at wavelength λ nm when the light enters the optical filter at 5 degrees from the optical lens group side,

TB5(λ): transmittance at wavelength λ nm when the light enters the cover glass at 5 degrees from the side opposite to the optical lens group.

In addition, T_NIR-30Is a value represented by the following formula.

[ numerical formula 4]

TA30(λ): a transmittance at a wavelength of λ nm when the light enters the optical filter from the optical lens group side at 30 degrees,

As a method for satisfying the conditions (1) and (2), that is, a method for adjusting the reflectance of light incident from the optical lens group 104 to the optical filter 111 and the reflectance of light incident from the optical lens group 104 to the cover glass 109 at the same time, for example, a method for providing a dielectric multilayer film having an antireflection effect at a wavelength of 700nm to 1200nm on one surface or both surfaces of the optical filter 111 can be cited.

By satisfying the conditions (1) and (2), when a light source of near-infrared light intensity is imaged, a high-quality camera image with less ghost can be obtained both at a low-angle incidence of 5 degrees and at a high-angle incidence of 30 degrees.

As a method for satisfying the conditions (3) and (4), that is, a method for adjusting the transmittance of light entering the optical filter 111 from the optical lens group 104 and the transmittance of light entering the cover glass 109 from the reflection surface of the optical lens group 104 while suppressing both, for example, a method for providing a dielectric multilayer film for shielding near infrared rays having a wavelength of 700nm to 1200nm on the cover glass can be mentioned.

By satisfying the conditions (3) and (4), a high-quality image with less ghost can be captured in the environment of near-infrared light intensity in both cases of low-angle incidence in which the incident angle of external light is 0 degrees and high-angle incidence in which the incident angle is 30 degrees.

As a method of satisfying all of the conditions (1) to (4), that is, a method of suppressing the reflectance of light incident from the optical lens group 104 to the optical filter 111 and the reflectance of light incident from the optical lens group 104 to the cover glass 109, and suppressing the transmittance of light incident from the optical lens group 104 to the optical filter 111 and the transmittance of light incident from the optical lens group 104 to the cover glass 109, in the optical characteristics of the optical filter 111 and the cover glass 109 incorporated in the camera module 100, for example, there are: a method of providing an antireflection film (dielectric multilayer film) having an antireflection effect at a wavelength of 700nm to 1200nm on one surface (for example, the surface on the optical lens group 104 side) or both surfaces of the optical filter 111, and providing a dielectric multilayer film for shielding near infrared rays at a wavelength of 700nm to 1200nm on one surface (the surface on the optical lens group 104 side) or both surfaces of the cover glass 109.

Since no dielectric multilayer film that reflects near infrared light having a wavelength of 700nm to 1200nm is provided in the optical filter 111 and the cover glass 109, ghost can be suppressed even when the near infrared light enters the optical system of the camera module 100. The near infrared rays having a wavelength of 700nm to 1200nm transmitted through the optical filter 111 and the cover glass 109 are effectively shielded, and therefore, the occurrence of flare due to the influence of the near infrared rays can be suppressed.

In order to satisfy the conditions (1) to (4), for example, the following configuration may be adopted: a dielectric multilayer film that shields near infrared rays having a wavelength of 700nm to 1200nm is provided on one side or both sides of the optical filter 111, and a dielectric multilayer film having an antireflection effect at a wavelength of 700nm to 1200nm is provided on one side or both sides of the cover glass 109, but a ghost can be further reduced by reducing reflected light of the optical filter 111 at a short distance from the imaging element, and in this point of view, a dielectric multilayer film having an antireflection effect at a wavelength of 700nm to 1200nm may be provided on one side or both sides of the optical filter 111, and a dielectric multilayer film that shields near infrared rays having a wavelength of 700nm to 1200nm may be provided on one side or both sides of the cover glass 109.

2-2-1 condition (1)

A minimum value T of transmittance of light incident from a direction perpendicular to the optical filter in a region having a wavelength of 430nm to 580nm_b-0And a minimum value T of transmittance of light incident from a direction inclined by 30 degrees with respect to the vertical direction_b-30Preferably 63% or more and 86% or less, and more preferably 67% or more and 82% or less. As a method for satisfying the condition (1), that is, a method for adjusting the minimum value of each transmittance, for example, a method for appropriately selecting and adjusting the type and the addition amount of the compound (a) described later so that the minimum value of the transmittance in a predetermined range can be obtained can be cited. By satisfying the condition (1), even when the light is incident at a high angle such as an incident angle of 30 degrees, the variation in RGB balance (color balance) can be reduced, and a high-quality image can be captured.

2-2-2 Condition (2)

In the region of 700nm to 780nm in wavelength, the average value OD of the optical density with respect to the light incident from the optical filter 111 in the vertical direction_a-0And the average OD of the optical densities with respect to light incident from a direction inclined by 30 degrees with respect to the vertical direction_a-30Preferably 1.8 or more and 4.0 or less, more preferably 1.9 or more and 3.5 or less, and an average value OD of optical density with respect to light incident from a direction inclined by 60 degrees with respect to the vertical direction_a-60Preferably 2.1 or more and 4.5 or less, and more preferably 2.2 or more and 4.0 or less.

As a method for satisfying the condition (2), that is, a method for adjusting the average value of the optical density (od) value, for example, a method for appropriately selecting and adjusting the kind and the addition amount of the compound (a) described later so that an average value of the transmittance in a predetermined range can be obtained can be cited.

By satisfying the condition (2), the optical filter can sufficiently cut not only near infrared rays transmitted in the vertical direction but also near infrared rays transmitted at a high incident angle, and therefore, an image without color shading or with reduced color shading can be captured.

Here, the OD value is a common logarithmic value of transmittance, and can be calculated by the following formula (1). When the average OD value in the predetermined wavelength range is high, it indicates that the cutoff characteristic of light in the wavelength region of the optical filter 111 is high.

[ numerical formula 5]

2-2-3 condition (3)

An average value T of transmittance of light incident from the vertical direction of the optical filter in a region of 900nm to 1200nm in wavelength_IRPreferably 70% to 98%, more preferably 80% to 95%, still more preferably 85% to 94%, and particularly preferably 89% to 93%.

As a method for satisfying the condition (3), that is, a method for adjusting the average value of the light transmittance, for example, a method for appropriately selecting and adjusting the kind and the addition amount of the compound (a) described later so that a transmittance in a predetermined range can be obtained can be cited.

By satisfying the condition (3), the transmittance in the near-infrared region is high, and the reflected light in the near-infrared region can be reduced, so that a camera image with reduced ghost can be obtained.

2-2-4 conditions (4)

An average value T of transmittance of light incident from the perpendicular direction of the optical filter in a region having a wavelength of 430nm to 580nm_a-0Preferably 73% or more and 88% or less, more preferably 76% or moreUp to 86%, and an average value T of transmittance of light incident from a direction inclined by 30 degrees with respect to the vertical direction_a-30Preferably 72% or more and 87% or less, more preferably 75% or more and 85% or less, and an average value T of transmittance of light incident from a direction inclined by 60 degrees with respect to the vertical direction_a-60Preferably 68% or more and 85% or less, more preferably 70% or more and 80% or less.

As a method for satisfying the condition (4), that is, a method for adjusting the average value of each transmittance, for example, a method for appropriately selecting and adjusting the kind and the addition amount of the compound (a) described later so that the average value of the transmittances in a predetermined range can be obtained can be cited.

By satisfying the condition (4), even when the light is incident at a high angle such as 30 degrees or 60 degrees, the RGB balance is less changed, and thus a high-quality camera image can be obtained.

3. Details of near-infrared light-absorbing parts (optical filters)

The following describes details of an optical filter as a near-infrared light absorbing section for satisfying the above conditions (1) to (4).

3-1. thickness of optical filter

The thickness of the optical filter 111 is preferably 210 μm or less, more preferably 190 μm or less, further preferably 160 μm or less, and particularly preferably 130 μm or less, and the lower limit is not particularly limited, and preferably 20 μm or more.

3-2. base material

The structure of the optical filter 111 is not particularly limited as long as the optical characteristics can be obtained, and preferably includes a base material satisfying the following condition (e), and more preferably satisfies the following condition (f).

The condition (e) includes a layer containing the compound (A) having an absorption maximum wavelength in a region of 650nm to 800nm in wavelength.

Condition (f) wavelength of 600-900 nm, wavelength X_aAnd wavelength X_bDifference | X of_b-X_a| is 100nm or more, the wavelength X_aThe transmittance of light incident from the perpendicular direction of the substrate is directed from the short wavelength side to the near wavelength sideA wavelength on the longest wavelength side of the wavelength X from more than 10% to 10% or less_bThe transmittance of light incident from the perpendicular direction of the substrate is changed from 10% or less to a wavelength on the shortest wavelength side exceeding 10% from the short wavelength side to the long wavelength side.

Hereinafter, each condition will be described.

3-3. Condition (e)

In the condition (e), the component constituting the layer containing the compound (a) is not particularly limited, and examples thereof include a transparent resin, a sol-gel material, a low-temperature-hardening glass material, and the like, and a transparent resin is preferable from the viewpoint of ease of handling and compatibility with the compound (a).

3-4. Compound (A)

The compound (a) is not particularly limited as long as it has an absorption maximum wavelength in a wavelength region of 650nm to 800nm, and is preferably at least one compound selected from the group consisting of squarylium compounds, phthalocyanine compounds, naphthalocyanine compounds, ketanium compounds and cyanine compounds, and particularly preferably squarylium compounds, phthalocyanine compounds and cyanine compounds. Further, the compound (a) may be used alone or in combination of two or more.

The squarylium compound has excellent visible light transmittance, steep absorption characteristics, and a high molar absorption coefficient, but sometimes generates fluorescence that causes scattered light when absorbing light. In this case, by using the squarylium compound in combination with the other compound (a), the optical filter 111 with less scattered light and better image quality can be obtained.

The absorption maximum wavelength of the compound (a) is preferably 660nm or more and 795nm or less, more preferably 680nm or more and 790nm or less.

The compound (a) is not particularly limited as long as it has an absorption maximum wavelength in a region of 650nm to 800nm in wavelength, and from the viewpoint of heat resistance of the optical filter, it is more preferable to include one or more compounds having an absorption maximum wavelength in a region of 650nm to 715nm in wavelength, a compound having an absorption maximum wavelength in a region of 715nm to 750nm in wavelength, and a compound having an absorption maximum wavelength in a region of 750nm to 800nm in wavelength, respectively.

When the compound (a) is a combination of two or more compounds, the difference in absorption maximum wavelength between the compound having the shortest absorption maximum wavelength and the compound having the longest absorption maximum wavelength in the compound (a) to be used is preferably 20nm to 100nm, more preferably 30nm to 90nm, and still more preferably 40nm to 80 nm. When the difference in absorption maximum wavelength is in the above range, it is preferable because scattered light due to fluorescence can be sufficiently reduced and a wide absorption band around 700nm and excellent visible light transmittance can be compatible with each other.

As the base material, for example, a base material including a transparent resin substrate containing the compound (a) can be used as the content of the whole compound (a). When a substrate is used in which a resin layer such as an overcoat layer containing a curable resin or the like is laminated on a transparent resin substrate containing the compound (a), the following substrate can be used: the compound (a) is contained preferably in an amount of 0.04 to 2.0 parts by mass, more preferably 0.06 to 1.5 parts by mass, and still more preferably 0.08 to 1.0 part by mass, based on 100 parts by mass of the transparent resin. When a substrate is used in which a transparent resin layer such as an overcoat layer containing a curable resin or the like containing the compound (a) is laminated on a support such as a glass support or a resin support as a base, the following substrate can be used: the compound (a) is contained preferably in an amount of 0.4 to 5.0 parts by mass, more preferably 0.6 to 4.0 parts by mass, and still more preferably 0.8 to 3.5 parts by mass, based on 100 parts by mass of the resin forming the transparent resin layer.

3-4-1. squarylium compounds

The squarylium compound includes a compound represented by the following formula (a 1).

[ solution 1]

In the formula (A1), X independently representsMethyl, or C2-C12 alkylene substituted with one or more hydrogen atoms, Z⁶、Z⁷、Z⁸Each independently represents a hydrogen atom, an aliphatic hydrocarbon group having 1 to 12 carbon atoms which may have a substituent, an aromatic hydrocarbon group having 6 to 12 carbon atoms which may have a substituent, or a heteroaromatic ring group having 5 to 20 carbon atoms which may have a substituent.

Z⁹Represents an aliphatic hydrocarbon group having 1 to 12 carbon atoms which may have a substituent, an aromatic hydrocarbon group having 1 to 12 carbon atoms which may have a substituent, and a heterocyclic functional group having 5 to 20 carbon atoms which may have a substituent.

Specific examples of the formula (A1) include compounds represented by the following formula (A1-1). The maximum absorption wavelength (. lamda.max) of the compound (A1-1) was 752 nm.

[ solution 2]

Examples of the squarylium compound other than the compound (A1) include compounds represented by the following formula (A1-2).

[ solution 3]

Further, as the compound having a maximum absorption wavelength at a longer wavelength side than the compound of formula (a1) among the squarylium compounds, a compound represented by formula (a2) can be mentioned.

[ solution 4]

In the formula (A2), Z⁶、Z⁷Each independently represents a hydrogen atom, an aliphatic hydrocarbon group having 1 to 12 carbon atoms which may have a substituent, an aromatic hydrocarbon group which may have a substituent, or a heterocyclic functional group having 5 to 20 carbon atoms which may have a substituent.

Specific examples of the formula (A2) include compounds represented by the following formula (A2-1). The maximum absorption wavelength (. lamda.max) of the compound (A2-1) was 776 nm.

[ solution 5]

The phthalocyanine compound may be a compound represented by the following formula (a 3).

[ solution 6]

In the formula (A3), Z¹⁰Independently represent a hydrogen atom, an aliphatic hydrocarbon having 1 to 12 carbon atoms which may have a substituent, an aromatic hydrocarbon group having 6 to 12 carbon atoms which may have a substituent, a heterocyclic functional group having 5 to 20 carbon atoms which may have a substituent, and M represents a metal, a metal or a metal oxide. Examples of the metal include Zn, Mg, Si, Sn, Rh, Pt, Pd, Mo, Mn, Pb, Cu, Ni, Co, Fe, etc., and examples of the metal oxide include VO, TiO, etc.

Specific examples of the formula (A3) include compounds represented by the following formula (A3-1). The maximum absorption wavelength (. lamda.max) of the compound (A3-1) was 738 nm.

[ solution 7]

The cyanine compound is a dye containing, as a dye, only a compound having a structure in which two hetero rings are conjugated and doubly bonded with an odd number of methines in a molecule. Specific examples of the cyanine compound include compounds represented by the following formulae (C1) and (C2).

[ solution 8]

In the formula (C1), Z¹Z represents an aliphatic hydrocarbon group having 1 to 12 carbon atoms which may have a substituent, an aromatic hydrocarbon group having 6 to 12 carbon atoms which may have a substituent, a heterocyclic functional group having 5 to 20 carbon atoms which may have a substituent²Represents an aliphatic hydrocarbon group having 1 to 12 carbon atoms which may have a substituent, an aromatic hydrocarbon group having 6 to 12 carbon atoms which may have a substituent, a heterocyclic functional group having 5 to 20 carbon atoms which may have a substituent, for example, one or more hydrogen atoms of a phenyl group or a naphthyl group may be substituted with a halogen or an alkyl group having 1 to 12 carbon atoms. In the formula (C2), Z³And Z⁴Each independently represents a hydrogen atom, an aliphatic hydrocarbon group having 1 to 12 carbon atoms which may have a substituent, an aromatic hydrocarbon group having 6 to 12 carbon atoms which may have a substituent, or a heterocyclic functional group having 5 to 20 carbon atoms which may have a substituent. n is an integer of 1 to 12. X represents a counter anion.

The substituents in the compound (a) may be exemplified by: halogen, hydroxyl group, aldehyde group, aliphatic hydrocarbon group having 1 to 12 carbon atoms, aromatic hydrocarbon group having 1 to 12 carbon atoms, alkoxy group having 1 to 12 carbon atoms, acyl group having 1 to 12 carbon atoms, ketone group, alkoxycarbonyl group having 2 to 12 carbon atoms, amine group in which one or more hydrogen atoms are substituted with aliphatic hydrocarbon group having 1 to 12 carbon atoms, imine group, nitrile group, amide group, cyano group, thiol group, thioether group of hydrocarbon group having 1 to 12 carbon atoms, dithiol group of hydrocarbon group having 1 to 12 carbon atoms, alkylsulfone group having 1 to 12 carbon atoms, heterocycle having 4 to 20 carbon atoms.

Examples of the counter anion of X include: halide ion, ClO₄ ^-、OH^-Organic carboxylate anions, organic sulfonate anions, lewis acid radical anions, organometallic complex anions, anions derived from pigments, organic sulfonyl imide acid radical anions, organic sulfonyl methide acid radical anions, and the like. The halide ion includes C1^-、Br^-、I^-And the like. Examples of the organic carboxylate anion include benzoate ion, alkanoate ion, trihaloalkanoate ion, and nicotinic acid ion. As organic sulfonic acidsRadical anions, there may be mentioned: benzene sulfonate ion, naphthalene sulfonate ion, p-toluene sulfonate ion, alkane sulfonate ion, and the like. Examples of the Lewis acid anion include: hexafluorophosphate ion, tetrafluoroborate ion, hexafluoroantimonate ion, tetrakis (pentafluorophenyl) boron anion, and the like.

Specific examples of the formula (C1) and the formula (C2) include compounds represented by the following formulae (C1-1) and (C2-1). The maximum absorption wavelength (. lamda.max) of the compound (C1-1) was 466nm, and the maximum absorption wavelength (. lamda.max) of the compound (C2-1) was 549 nm.

[ solution 9]

[ solution 10]

[ solution 11]

The substrate may be a single layer or a plurality of layers if it has a layer containing the compound (a).

3-5. thickness of base material

The thickness of the substrate is not particularly limited and may be suitably selected depending on the intended use, but is preferably 10 to 200 μm, more preferably 20 to 180 μm, and still more preferably 25 to 150 μm. When the thickness of the base material is within the above range, the optical filter using the base material can be made thin and light in weight, and can be suitably used for various applications such as a solid-state imaging device. In particular, when a base material including a transparent resin substrate is used for a lens unit such as a camera module, the lens unit is preferably reduced in height and weight.

3-6 transparent resin

The transparent resin is not particularly limited as long as the effect of the present invention is not impaired, and for example, in order to ensure thermal stability and moldability into a film, there are exemplified: the glass transition temperature (Tg) is preferably 110 to 380 ℃, more preferably 110 to 370 ℃, and still more preferably 120 to 360 ℃. In order to be suitable for the reflow step, the glass transition temperature of the resin is preferably 140 ℃ or higher, and more preferably 230 ℃ or higher.

The transparent resin used in the present invention is preferably 75 to 95%, more preferably 78 to 95%, and particularly preferably 80 to 95% of the total light transmittance (JIS K7105) of a resin sheet having a thickness of 0.1mm and containing the resin. When a resin having such a total light transmittance is used, the obtained substrate exhibits good transparency as an optical film.

The transparent resin has a weight average molecular weight (Mw) of usually 15,000 to 350,000, preferably 30,000 to 250,000, and a number average molecular weight (Mn) of usually 10,000 to 150,000, preferably 20,000 to 100,000, in terms of polystyrene, as measured by a Gel Permeation Chromatography (GPC) method.

Examples of the transparent resin include: a cyclic polyolefin-based resin, an aromatic polyether-based resin, a polyimide-based resin, a fluorene polycarbonate-based resin, a fluorene polyester-based resin, a polycarbonate-based resin, a polyamide-based resin, an aromatic polyamide-based resin, a polysulfone-based resin, a polyether sulfone-based resin, a polyphenylene-based resin, a polyamideimide-based resin, a polyethylene naphthalate-based resin, a fluorinated aromatic polymer-based resin, a (modified) acrylic-based resin, an epoxy-based resin, a silsesquioxane-based ultraviolet curable resin, a maleimide-based resin, an alicyclic epoxy thermosetting resin, a polyether ether ketone-based resin, a polyarylate-based resin, an allyl-based curable resin, an acrylic-based ultraviolet curable resin, a vinyl-based ultraviolet curable resin, and a resin containing silica formed by a sol-gel method as a main component. Among these, in order to obtain an optical filter having an excellent balance among transparency (optical characteristics), heat resistance, reflow resistance, and the like, it is preferable to use a cyclic polyolefin resin, an aromatic polyether resin, a fluorene polycarbonate resin, a fluorene polyester resin, a polycarbonate resin, and a polyarylate resin. The transparent resin may be used alone or in combination of two or more.

3-6-1. Cyclic polyolefin-based resin

The cyclic polyolefin resin is preferably a cyclic polyolefin resin selected from the group consisting of the following formula (X)₀) A monomer represented by the formula (Y)₀) A resin obtained from at least one monomer of the group consisting of the monomers represented, and a resin obtained by hydrogenating the resin.

[ solution 12]

Formula (X)₀) In, R^X1～R^X4Each independently represents an atom or a group selected from the following (i ') to (ix'), k^X、m^XAnd p^XEach independently represents 0 or a positive integer.

(i') a hydrogen atom

(ii') a halogen atom

(iii') Trialkylsilyl group

(iv') a substituted or unsubstituted hydrocarbon group having 1 to 30 carbon atoms and having a linking group containing an oxygen atom, a sulfur atom, a nitrogen atom or a silicon atom

(v') a substituted or unsubstituted hydrocarbon group having 1 to 30 carbon atoms

(vi ') a polar group (wherein (iv') is excluded)

(vii′)R^X1And R^X2Or R^X3And R^X4Alkylene groups formed by bonding to each other (wherein R does not participate in the bond)^X1～R^X4Each independently represents an atom or group selected from (i ') to (vi')

(viii′)R^X1And R^X2Or R^X3And R^X4Monocyclic or polycyclic hydrocarbon rings or heterocycles formed by bonding to one another (in which R does not participate in the bond)^X1～R^X4Each independently represents an atom or group selected from (i ') to (vi')

(ix′)R^X2And R^X3A monocyclic hydrocarbon ring or heterocyclic ring formed by bonding to each other (wherein R not participating in bonding is^X1And R^X4Each independently represents an atom or group selected from (i ') to (vi')

[ solution 13]

Formula (Y)₀) In, R^y1And R^y2Each independently represents an atom or a group selected from (i ') to (vi'), or R^y1And R^y2A monocyclic or polycyclic alicyclic, aromatic or heterocyclic ring formed by bonding to each other, k^yAnd p^yEach independently represents 0 or a positive integer.

3-6-2, commercially available products

As a commercially available product of the transparent resin, the following commercially available products can be mentioned. Examples of commercially available products of the cyclic polyolefin resin include: anton (Arton) manufactured by JSR (stock), renooa (Zeonor) manufactured by nippon (stock), Apiel (APEL) manufactured by mitsui chemical (stock), TOPAS (TOPAS) manufactured by polyplasics (stock), and the like.

3-7. other pigments (X)

The base material may further contain another pigment (X) which does not correspond to the compound (A).

The other dye (X) is not particularly limited as long as it has an absorption maximum wavelength in a region having a wavelength of less than 650nm or a wavelength of more than 800nm and 1250nm or less, and examples thereof include at least one compound selected from the group consisting of squarylium compounds, phthalocyanine compounds, cyanine compounds, naphthalocyanine compounds, croconium compounds, octaporphyrin compounds, diimmonium compounds, pyrrolopyrrole compounds, boron dipyrromethene (BODIPY) compounds, perylene compounds, and metal dithiolate compounds. By using such a dye, absorption characteristics in a wide near infrared wavelength region and excellent visible light transmittance can be achieved.

The absorption maximum wavelength of the other dye (X) is preferably 805nm or more and 1200nm or less, and more preferably 810nm or more and 1150nm or less. When the absorption maximum wavelength of the other dye (X) is in such a range, unnecessary near infrared rays can be efficiently cut off, and incident angle dependency of incident light can be reduced.

For example, when a substrate including a transparent resin substrate containing another pigment (X) is used as the substrate, the content of the other pigment (X) is preferably 0.005 to 1.0 part by mass, more preferably 0.01 to 0.9 part by mass, and particularly preferably 0.02 to 0.8 part by mass, based on 100 parts by mass of the transparent resin, and when a substrate including a transparent resin layer such as an overcoat layer containing another pigment (X) and including a curable resin and the like laminated on a support such as a glass support or a resin support serving as a base, or a substrate including a resin layer such as an overcoat layer containing another pigment (X) and including a curable resin and the like laminated on a transparent resin substrate containing the compound (a), the content of the other pigment (X) is preferably 0.05 to 4.0 parts by mass, based on 100 parts by mass of the resin forming the transparent resin layer containing the other pigment (X), more preferably 0.1 to 3.0 parts by mass, and particularly preferably 0.2 to 2.0 parts by mass.

3-8. other ingredients

The base material may further contain an antioxidant, a near-ultraviolet absorber, a fluorescent matting agent, and the like as other components within a range not to impair the effects of the present invention. These other components may be used alone or in combination of two or more.

Examples of the near-ultraviolet absorber include: azomethine compounds, indole compounds, benzotriazole compounds, triazine compounds, and the like.

Examples of the antioxidant include: 2, 6-di-tert-butyl-4-methylphenol, 2 ' -dioxy-3, 3 ' -di-tert-butyl-5, 5 ' -dimethyldiphenylmethane, tetrakis [ methylene-3- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate ] methane, tris (2, 4-di-tert-butylphenyl) phosphite, and the like.

These other components may be mixed with the resin or the like at the time of producing the base material, or may be added at the time of synthesizing the resin. The amount of the additive is appropriately selected depending on the desired properties, and is usually 0.01 to 5.0 parts by mass, preferably 0.05 to 2.0 parts by mass, based on 100 parts by mass of the resin.

3-9. method for producing base Material

When the base material is a base material comprising a transparent resin substrate containing the compound (a), the transparent resin substrate can be formed by, for example, melt molding or cast molding, and further, if necessary, a base material on which an overcoat layer is laminated can be produced by applying a coating agent such as an antireflective agent, a hard coat agent, and/or an antistatic agent after molding.

When the substrate is a substrate in which a transparent resin layer containing the compound (a) such as an overcoat layer made of a curable resin or the like is laminated on a support such as a glass support or a resin support as a base or on a transparent resin substrate not containing the compound (a), for example, a resin solution containing the compound (a) is melt-molded or cast-molded on the support or the transparent resin substrate, and preferably, the substrate is coated by a method such as spin coating, slit coating, or ink jet, then the solvent is dried and removed, and further, light irradiation or heating is performed as necessary, whereby a substrate in which a transparent resin layer containing the compound (a) is formed on the support or the transparent resin substrate can be produced.

3-9-1. melt forming

Specific examples of the melt molding include: a method of melt-molding pellets obtained by melt-kneading a resin, the compound (a) and, if necessary, other components; a method of melt-molding a resin composition containing a resin, a compound (A) and, if necessary, other components; or a method of melt-molding pellets obtained by removing the solvent from a resin composition containing the compound (a), the resin, the solvent, and optionally other components. Examples of the melt molding method include injection molding, melt extrusion molding, and blow molding.

3-9-2. casting and forming

The cast molding can also be produced by the following method: a method of casting a resin composition containing the compound (a), a resin, a solvent and, if necessary, other components on a suitable support and removing the solvent; or a method in which a curable composition containing the compound (a), a photocurable resin and/or a thermosetting resin, and optionally other components is cast on a suitable support, the solvent is removed, and then curing is performed by an appropriate method such as ultraviolet irradiation or heating.

When the substrate is a substrate comprising a transparent resin substrate containing the compound (a), the substrate can be obtained by peeling the coating film from a support after casting, and when the substrate is a substrate in which a transparent resin layer containing the compound (a) such as an overcoat layer comprising a curable resin or the like is laminated on a support such as a glass support or a resin support as a base or a transparent resin substrate not containing the compound (a), the substrate can be obtained by not peeling the coating film after casting.

Examples of the support include: examples of the near-infrared absorbing glass plate include a near-infrared absorbing glass plate (e.g., a phosphate glass plate containing a copper component such as "BS 1 to BS 13" manufactured by sonlang nitre industries or "NF-50T" manufactured by AGC technologies), a transparent glass plate (e.g., AN alkali-free glass plate such as "OA-10G" manufactured by japan electric glass works or "AN 100" manufactured by asahi nitre companies, or a crown glass (crown glass) plate such as "BK 7" and "D263 Teco" manufactured by Schottky (SCHOTT), a steel band, a steel tub, and a support made of a transparent resin (e.g., a polyester film or a cyclic olefin resin film).

Further, the transparent resin layer may be formed on the optical component by the following method or the like: a method of applying the resin composition to an optical component made of glass plate, quartz, transparent plastic, or the like and drying the solvent; or a method of applying a curable composition, curing and drying.

The amount of the residual solvent in the transparent resin layer (transparent resin substrate) obtained by the above method is preferably as small as possible. Specifically, the amount of the residual solvent is preferably 3 wt% or less, more preferably 1 wt% or less, and still more preferably 0.5 wt% or less, based on the weight of the transparent resin layer (transparent resin substrate). When the amount of the residual solvent is within the above range, a transparent resin layer (transparent resin substrate) which is hardly deformed or hardly changed in properties and can easily exhibit a desired function can be obtained.

3-10 dielectric multilayer film (antireflection film with respect to visible light)

The optical filter of the present invention preferably includes a dielectric multilayer film having an antireflection effect. At least one surface of the cover glass may have a dielectric multilayer film that reflects near infrared rays, within a range that does not impair the effects of the present invention. The dielectric multilayer film included in the optical filter of the present invention is a film having an antireflection effect in the visible region.

The dielectric multilayer film preferably has antireflection properties over the entire wavelength range of preferably 400nm to 800nm, more preferably 410nm to 750nm, and still more preferably 420nm to 700 nm.

Examples of the form having the dielectric multilayer film on both surfaces of the base include the following forms: the dielectric multilayer film has antireflection properties mainly at wavelengths of 400 to 800nm on both surfaces of the base material when measured in a direction perpendicular to the optical filter.

The thickness of the dielectric multilayer film having an antireflection effect in the visible region is not particularly limited as long as the effect of the present invention is not impaired, but is preferably 0.01 μm to 1.0 μm, and more preferably 0.05 μm to 0.5 μm. By setting the thickness to the above range, an optical filter with less warpage or strain can be obtained.

As the dielectric multilayer film, a multilayer film in which high refractive index material layers and low refractive index material layers are alternately laminated can be cited. As the material constituting the high refractive index material layer, a material having a refractive index of 1.7 or more can be used, and a material having a refractive index of usually 1.7 to 2.5 is selected. Examples of such materials include: a material containing titanium oxide, zirconium oxide, tantalum pentoxide, niobium pentoxide, lanthanum oxide, yttrium oxide, zinc sulfide, indium oxide, or the like as a main component and a small amount (for example, 0 to 10% by weight with respect to the main component) of titanium oxide, tin oxide, cerium oxide, or the like.

As a material constituting the low refractive index material layer, a material having a refractive index of less than 1.7 can be used, and a material having a refractive index of usually 1.2 to less than 1.7 is selected. Examples of such materials include: silica, alumina, lanthanum fluoride, magnesium fluoride, and sodium aluminum hexafluoride, and materials obtained by mixing these.

The method of laminating the high refractive index material layer and the low refractive index material layer is not particularly limited as long as a dielectric multilayer film in which these material layers are laminated is formed. For example, a dielectric multilayer film in which high refractive index material layers and low refractive index material layers are alternately stacked may be directly formed on a substrate by a Chemical Vapor Deposition (CVD) method, a sputtering method, a vacuum evaporation method, an ion-assisted evaporation method, an ion plating method, or the like.

In general, when the wavelength of the near infrared ray to be blocked is λ (nm), the thickness of each of the high refractive index material layer and the low refractive index material layer is preferably 0.1 λ to 0.5 λ. The value of λ (nm) is, for example, 700nm to 1400nm, preferably 750nm to 1300 nm. When the thickness is within the above range, the product (n × d) of the refractive index (n) and the film thickness (d) is substantially the same as the optical film thickness calculated by λ/4 and the thickness of each of the high refractive index material layer and the low refractive index material layer, and the blocking and transmission of a specific wavelength tends to be easily controlled in accordance with the relationship between the optical characteristics of reflection and refraction.

The number of layers of the dielectric multilayer film included in the optical filter, which are stacked together from the high refractive index material layer and the low refractive index material layer, is preferably 1 to 20 layers, and more preferably 2 to 12 layers, based on the entire optical filter. By setting the number of layers to the above range, an optical filter with less warpage or strain can be obtained.

In one embodiment of the present invention, the material types of the high refractive index material layer and the low refractive index material layer, the thicknesses of the respective layers of the high refractive index material layer and the low refractive index material layer, the order of lamination, and the number of lamination are appropriately selected in accordance with the absorption characteristics of the compound (a) or the other pigment (X), whereby a sufficient transmittance is ensured in the visible region, a sufficient light cut-off characteristic is provided in the near infrared wavelength region, and the reflectance when near infrared rays enter from an oblique direction can be reduced.

3-11 anti-reflection layer

The anti-reflection layer according to an embodiment of the present invention has an effect of further reducing the reflectance of the substrate alone in light of a specific wavelength. Specifically, the layer having the following effects is shown: the reflectance of light having a wavelength having an antireflection effect is 4% or less with respect to light incident from the vertical direction of the incident surface. As the antireflection layer, there can be mentioned: a dielectric single layer film having a refractive index lower than that of the substrate, a dielectric multilayer film, and a cone or polygonal cone structure (so-called moth eye) having a height, width, or depth smaller than the wavelength of light for antireflection.

3-12. other functional films

In the optical filter according to one embodiment of the present invention, a functional film such as an antireflection film, a hard coat film, or an antistatic film may be appropriately provided on at least one surface of the substrate, between the substrate and the dielectric multilayer film, on a surface of the substrate opposite to the surface on which the dielectric multilayer film is provided, or on a surface of the dielectric multilayer film opposite to the surface on which the substrate is provided, for the purpose of improving the surface hardness of the substrate or the dielectric multilayer film, improving chemical resistance, preventing static electricity, and eliminating damage, within a range not to impair the effects of the present invention.

The optical filter according to an embodiment of the present invention may include one layer including the functional film, or may include two or more layers. When the optical filter of the present invention includes two or more layers including a functional film, the optical filter may include two or more layers of the same type or two or more layers of different types.

The method of laminating the functional film is not particularly limited, and examples thereof include: and a method of melt-molding or cast-molding a coating agent such as an antireflective agent, a hard coat agent, and/or an antistatic agent on a substrate or a dielectric multilayer film in the same manner as described above.

Alternatively, the dielectric multilayer film can be produced by applying a curable composition containing a coating agent or the like to a substrate or a dielectric multilayer film using a bar coater or the like, and then curing the composition by ultraviolet irradiation or the like.

Examples of the coating agent include Ultraviolet (UV)/Electron Beam (EB) curable resins and thermosetting resins, and specific examples thereof include: vinyl compounds, urethane, acrylic ester, epoxy and epoxy acrylate resins, and the like. As the curable composition containing these coating agents, there can be mentioned: and curable compositions of vinyl, urethane, acrylic urethane, acrylate, epoxy, and epoxy acrylate.

In addition, the curable composition may contain a polymerization initiator. As the polymerization initiator, a known photopolymerization initiator or thermal polymerization initiator can be used, or a photopolymerization initiator and a thermal polymerization initiator can be used in combination. One kind of the polymerization initiator may be used alone, or two or more kinds may be used in combination.

In the curable composition, the proportion of the polymerization initiator to be blended is preferably 0.1 to 10% by weight, more preferably 0.5 to 10% by weight, and still more preferably 1 to 5% by weight, based on 100% by weight of the total amount of the curable composition. When the blending ratio of the polymerization initiator is in the above range, a functional film such as an antireflection film, a hard coat film or an antistatic film having excellent curing characteristics and workability of the curable composition and having a desired hardness can be obtained.

Further, an organic solvent may be added to the curable composition as a solvent, and a known solvent may be used as the organic solvent. Specific examples of the organic solvent include: alcohols such as methanol, ethanol, isopropanol, butanol, and octanol; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; esters such as ethyl acetate, butyl acetate, ethyl lactate, γ -butyrolactone, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, and the like; ethers such as ethylene glycol monomethyl ether and diethylene glycol monobutyl ether; aromatic hydrocarbons such as benzene, toluene, and xylene; amides such as dimethylformamide, dimethylacetamide and N-methylpyrrolidone. One solvent may be used alone, or two or more solvents may be used in combination.

The thickness of the functional film is preferably 0.1 to 20 μm, more preferably 0.5 to 10 μm, and particularly preferably 0.7 to 5 μm.

In addition, for the purpose of improving the adhesion between the substrate and the functional film and/or the dielectric multilayer film or the adhesion between the functional film and the dielectric multilayer film, the surface of the substrate, the functional film, or the dielectric multilayer film may be subjected to a surface treatment such as corona treatment or plasma treatment.

4. Optical lens group

The camera module according to one embodiment of the present invention includes 12 or less optical lens groups. The material constituting the optical lens group is preferably a transparent resin, glass, metal oxide, or metal nitride. From the viewpoint of suppressing ghost caused by reflected light between the optical lens groups, more preferably 6 to 11 pieces. In the case where the focal point of light is combined with the sensor by an optical lens group having a curvature including transparent resin or glass, it is preferable that the lens surface of the optical lens group has an antireflection film. As the optical lens group, a super lens (metalens) including a metal oxide structure having a size of less than 1 μm can be used, and the super lens is more preferably used because the obtained image pickup device can be further reduced in back. The CRA of the optical lens group is preferably 30 degrees or more and 60 degrees or less. In the case of less than 30 degrees, the angle of view of an image obtained with respect to the angle of view of a person is narrow, and a scene that can be photographed is limited. When the angle is 60 degrees or more, the decrease in the light amount near the edge of the sensor pixel is large, and it is difficult to maintain the contrast in both the image center and the image peripheral portion.

The camera module according to one embodiment of the present invention is mounted between optical lens groups as shown in fig. 2 (B), or mounted below the optical lens groups or on the sensor side as shown in fig. 2 (C), from the viewpoint of suppressing ghost caused by stray light incident at a very high angle. From the viewpoint that the distance between the sensor and the optical filter is long and ghost can be further suppressed, it is more preferable to mount the optical filter between the optical lens groups as shown in fig. 2 (B).

5. Use of a camera module

The camera module according to an embodiment of the present invention has a wide viewing angle, and can obtain an image with little flare, color shading, and ghost. Therefore, the present invention is particularly useful for camera modules, digital still cameras, cameras for smartphones, cameras for mobile phones, digital video cameras, cameras for wearable devices (Personal computers), cameras for Personal Computers (PCs), surveillance cameras, cameras for automobiles, televisions, car navigation (car navigation), Personal digital assistants, video game machines, portable game machines, retina authentication systems, eyeball authentication systems, vein authentication systems, fingerprint authentication systems, digital music players, and the like. The camera module is a module including a solid-state imaging device such as a CCD or CMOS image sensor, and is specifically used for applications such as a digital still camera, a camera for a smartphone, a camera for a mobile phone, a camera for a wearable device, and a digital video camera. For example, the camera module of an embodiment of the present invention includes an optical filter 111. Here, the camera module includes an image sensor, a focus adjustment mechanism, a phase detection mechanism, a distance measurement mechanism, and the like, and outputs image or distance information as an electric signal.

An electronic device according to an embodiment of the present invention includes the camera module of the present invention. The electronic device is not particularly limited, and examples thereof include a smartphone, a mobile phone, and a PC for the above-described applications.

[ examples ]

6. Each physical property value

The present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples. The term "part" means "part by mass" unless otherwise specified. The measurement method of each physical property value and the evaluation method of the physical property are as follows.

6-1. molecular weight

The molecular weight of the resin is measured by the following method (a) or (b) in consideration of the solubility of each resin in a solvent and the like.

(a) The weight-average molecular weight (Mw) and the number-average molecular weight (Mn) in terms of standard polystyrene were measured using a Gel Permeation Chromatography (GPC) apparatus (model 150C, column: H column manufactured by Tosoh corporation, developing solvent: o-dichlorobenzene).

(b) The weight average molecular weight (Mw) and the number average molecular weight (Mn) in terms of standard polystyrene were measured using a GPC apparatus (HLC-8220 type, column: TSKgel. alpha. -M, developing solvent: Tetrahydrofuran (THF)).

Further, with respect to the resin synthesized in resin synthesis example 3 described later, the logarithmic viscosity was measured by the following method (c) without measuring the molecular weight by the above-mentioned method.

6-2. glass transition temperature (Tg)

Using a differential scanning calorimeter (DSC6200) manufactured by seiko electronic Nanotechnologies (SII Nanotechnologies) ltd, a temperature rise rate: the measurement was carried out at 20 ℃ per minute under a nitrogen stream.

6-3. spectral transmittance

The transmittance at each wavelength of the substrate and the optical filter was measured by using a spectrophotometer (U-4100) manufactured by Hitachi High-Technologies, Inc.

Here, as the transmittance when the measurement is performed from the perpendicular direction of the optical filter, the light 2 that is transmitted perpendicularly to the optical filter 1 is measured by the spectrophotometer 3 as in fig. 1 (a), and as the transmittance when the measurement is performed from the angle of 30 degrees with respect to the perpendicular direction of the optical filter, the light 2 'that is transmitted at the angle of 30 degrees with respect to the perpendicular direction of the optical filter 1 is measured by the spectrophotometer 3 as in fig. 1 (B), and as the transmittance when the measurement is performed from the angle of 60 degrees with respect to the perpendicular direction of the optical filter, the light 2' that is transmitted at the angle of 60 degrees with respect to the perpendicular direction of the optical filter 1 is measured by the spectrophotometer 3 as in fig. 1 (C).

7. Evaluation of camera images

As evaluation items of the camera image, color shading evaluation, flare evaluation, and ghost evaluation were performed. Hereinafter, the contents of each item are shown.

7-1. color shading evaluation of Camera images

The color shade evaluation when the optical filter is incorporated into the camera module is performed by the following method. A camera module as shown in fig. 2 was produced in the same manner as in japanese patent laid-open No. 2016-110067, and a white plate (a white plate cut out in the above dimensions from a standard reflective target CSRT-99-180 of spiklaon (Spectralon) manufactured by blue-ray optics) having a size of 300mm × 400mm was photographed with a D65 light source (a standard light source device "Macbeth Judge a (II)" manufactured by alice (X-Rite)). The difference in color tone between the center (position 150mm in the vertical direction and 200mm in the horizontal direction) and the end (position 280mm in the vertical direction and 380mm in the horizontal direction) of the white plate in the camera image was evaluated by the following criteria.

A level that is completely free from problems and is acceptable is determined as A, a level that is found to be slightly different in hue and is practically free from problems and acceptable as a high-quality camera module is determined as B, a level that is different in hue and is not acceptable for use as a high-quality camera module is determined as C, and a level that is significantly different in hue and is not acceptable for use as a general camera module is determined as D.

As shown in fig. 4, the positional relationship between the white plate 202 and the camera module is adjusted so that the white plate 202 occupies 90% or more of the area of the camera image 200 when shooting. As the cover glass 109x in fig. 2, a cover glass having a film structure shown in table 1 below was used, and as the optical filter 111x, the optical filters prepared in the following examples and comparative examples were used.

[ Table 1]

7-2. evaluation of flare from camera images

The evaluation of flare when the optical filter is incorporated into the camera module is performed by the following method. The camera module shown in fig. 2 is manufactured by the same method as that of japanese patent laid-open No. 2016-110067. As the cover glass 109x in fig. 2, the cover glass 1 having the film configuration shown in table 1 was used, and as the optical filter 111x, the optical filters fabricated in the following examples and comparative examples were used.

The produced camera module was used to photograph in a dark room under a halogen lamp light source ("luminal Ace (r) LA-150 TX") and the occurrence of flare around the light source in the camera image was evaluated by the following criteria.

A level which is completely free from problems and is tolerable is determined as A, a level which is found to have a few flare points but is practically free from problems and is tolerable as a high-quality camera module is determined as B, a level which is generated flare points and is not tolerable for use as a high-quality camera module is determined as C, and a level which is serious in flare point and is not tolerable for use as a general camera module is determined as D.

As shown in fig. 5, the halogen lamp light source is arranged at a distance of 1mm from the camera module at the time of photographing, and is adjusted so as to be the center of the camera image 208. The focus was adjusted to the position of the light source with the sensitivity of the International Standardization Organization (ISO) set to 100. In the obtained image, a spot located inside a circle having the same center as the light source and having a radius twice that of the light source and outside the circle of the light source is evaluated as a spot 212 around the light source.

7-3 ghost evaluation of Camera images

The ghost evaluation when the optical filter is incorporated into the camera module is performed by the following method. A camera module was produced by the same method as the flare evaluation of the camera image, and the produced camera module was used to perform imaging in a dark room under a halogen lamp light source ("luminal Ace) LA-150 TX" manufactured by linchman industries, inc.

The allowable level with no problem at all is determined as a, the allowable level with no problem in practice as a high-quality camera module with a few ghosts confirmed is determined as B, the allowable level with no problem in practice as a high-quality camera module with a ghost generated is determined as C, and the allowable level with a severe degree of ghost and for general use as a camera module is determined as D.

As shown in fig. 6, the halogen lamp light source 216 is arranged at a distance of 1mm from the camera module at the time of shooting, and is adjusted so as to be the upper right end portion of the camera image 214 (the same position as the end portion of the camera image for color shading evaluation). The ghost generated at the position closest to the light source is taken as a ghost 218 at the periphery of the light source.

8. Synthesis example

The compound (a) and the near-infrared absorbing dye (X) used in the following examples were synthesized by a conventionally known method. Examples of the general synthesis method include methods described in Japanese patent laid-open publication No. 60-228448, Japanese patent laid-open publication No. 1-146846, Japanese patent laid-open publication No. 1-228960, Japanese patent laid-open publication No. 4081149, Japanese patent laid-open publication No. 63-124054, phthalocyanine-chemical and function complex (IPC, 1997), Japanese patent laid-open publication No. 2007-169383, Japanese patent laid-open publication No. 2009-108267, and Japanese patent laid-open publication No. 2010-241873.

8-1 resin Synthesis example 1

The following 8-methyl-8-methoxycarbonyltetracyclo [4.4.0.1 ] is introduced^2，5.1^7，10]100 parts of dodec-3-ene (hereinafter, also referred to as "DNM"), 18 parts of 1-hexene (molecular weight modifier) and 300 parts of toluene (solvent for ring-opening polymerization) were charged in a reaction vessel purged with nitrogen, and the solution was heated to 80 ℃. Then, 0.2 part (0.6 mol/liter) of a toluene solution of triethylaluminum as a polymerization catalyst was added to the solution in the reaction vesselAnd 0.9 part of a toluene solution (concentration: 0.025 mol/liter) of methanol-modified tungsten hexachloride, and the solution was heated and stirred at 80 ℃ for 3 hours to perform a ring-opening polymerization reaction to obtain a ring-opening polymer solution. The polymerization conversion in the polymerization reaction was 97%.

[ solution 14]

1,000 parts of the ring-opened polymer solution thus obtained was charged into an autoclave, and 0.12 part of RuHCl (CO) [ P (C) was added to the ring-opened polymer solution₆H₅)₃]₃At a hydrogen pressure of 100kg/cm²And the reaction temperature was 165 ℃ and the mixture was stirred with heating for 3 hours to effect hydrogenation. After the obtained reaction solution (hydrogenated polymer solution) was cooled, the pressure of hydrogen gas was released. The reaction solution was poured into a large amount of methanol, and then a coagulated product was separated and recovered, and dried to obtain a hydrogenated polymer (hereinafter, also referred to as "resin a"). The obtained resin A had a number average molecular weight (Mn) of 32,000, a weight average molecular weight (Mw) of 137,000, and a glass transition temperature (Tg) of 165 ℃.

[ example 1]

100 parts of the resin A obtained in resin Synthesis example 1, 0.05 part of a compound represented by the following formula (A1-1) (absorption maximum wavelength in methylene chloride (712 nm)), 0.12 part of a compound represented by the following formula (A3-1) (absorption maximum wavelength in methylene chloride (738 nm)), 0.05 part of a compound represented by the following formula (A2-1) (absorption maximum wavelength in methylene chloride (776 nm)), and methyl chloride (methyl chloride) were charged into a vessel to prepare a solution having a resin concentration of 20% by weight. The obtained solution was cast onto a smooth glass plate, dried at 20 ℃ for 8 hours, and then peeled from the glass plate. The peeled coating film was dried at 100 ℃ for 8 hours under reduced pressure to obtain a base material comprising a transparent resin substrate having a thickness of 0.1mm, a vertical length of 60mm and a horizontal length of 60 mm.

As dielectric multilayer films(I) Silicon dioxide (SiO) with a film thickness of 10nm to 132nm is alternately laminated on both sides of a substrate by ion-assisted deposition at a deposition temperature of 120 DEG C₂) Titanium dioxide (TiO) with a layer and film thickness of 21nm to 110nm₂) Layers (total of 8 layers). The silica layer and the titania layer of the dielectric multilayer film (I) are alternately laminated in the order of the titania layer, the silica layer, the titania layer, and the silica layer from the substrate side, and the outermost layer of the optical filter is the silica layer. The film composition is shown in table 2 below.

[ Table 2]

*λ＝550nm

The spectral transmittance of the optical filter including the base material was measured, and the optical characteristics were evaluated. Further, a camera module having the optical filter incorporated at the position of (B) in fig. 2 was produced using the obtained optical filter, and flare evaluation, color shading evaluation, and ghost evaluation of the camera image were performed. The results are shown in fig. 7 and table 4.

[ solution 15]

[ solution 16]

[ solution 17]

[ example 2]

A transparent resin substrate was obtained in the same manner and under the same conditions as in example 1 except that 0.03 parts of the compound represented by the following formula (A1-2) (the absorption maximum wavelength in methylene chloride was 686nm), 0.04 parts of the compound represented by the formula (A2-1) and 0.06 parts of the compound represented by the following formula (C2-2) (the absorption maximum wavelength in methylene chloride was 760nm) were used in example 1.

[ solution 18]

[ solution 19]

On one side of the obtained transparent resin substrate, a resin composition (1) having the following composition was applied by a bar coater, and heated at 70 ℃ for 2 minutes in an oven to evaporate and remove the solvent. At this time, the coating conditions of the bar coater were adjusted so that the thickness after drying was 2 μm. Next, exposure was carried out using a belt type exposure machine (exposure amount: 500 mJ/cm)²200mW), and curing the resin composition (1) to form a resin layer on a transparent resin substrate. Similarly, a resin layer containing the resin composition (1) was formed on the other surface of the transparent resin substrate, and a substrate having resin layers on both surfaces of the transparent resin substrate was obtained. On both sides of the obtained base material, a dielectric multilayer film (I) was provided in the same manner as in example 1, to obtain an optical filter. The spectral transmittance of the optical filter was measured to evaluate the optical characteristics. Further, a camera module was produced using the obtained optical filter, and flare evaluation, color shading evaluation, and ghost evaluation of the camera image were performed. The results are shown in fig. 8 and table 4.

Resin composition (1): 60 parts of tricyclodecane dimethanol diacrylate, 40 parts of dipentaerythritol hexaacrylate, 5 parts of 1-hydroxycyclohexyl phenyl ketone, and 30% of methyl ethyl ketone (solvent, Total Solid Concentration (TSC)))

[ example 3]

A base material including a substrate made of a transparent resin was obtained in the same manner and under the same conditions as in example 1 except that in example 1, 0.04 parts of the (a1-1) compound, 0.03 parts of the (a1-2) compound, 0.10 parts of the (A3-1) compound, 0.04 parts of the (a2-1) compound, and 0.05 parts of the (C2-2) compound were used. On both sides of the obtained base material, a dielectric multilayer film (I) was provided in the same manner as in example 1, to obtain an optical filter. The spectral transmittance of the optical filter was measured to evaluate the optical characteristics. Further, a camera module having the optical filter incorporated at the position of (B) in fig. 2 was produced using the obtained optical filter, and flare evaluation, color shading evaluation, and ghost evaluation of the camera image were performed. The results are shown in fig. 9 and table 4.

[ example 4]

A base material comprising a transparent resin substrate containing the compound (a) and the near-infrared absorbing dye (X) was obtained in the same procedure and under the same conditions as in example 1 except that in example 1, 0.04 parts of the compound (a1-1), 0.03 parts of the compound (a1-2), 0.01 parts of the compound (A3-1), 0.03 parts of the compound (a2-1), 0.04 parts of the compound (C2-2) and 0.04 parts of the near-infrared absorbing dye (XA) represented by the following formula (XA) (absorption maximum wavelength in dichloromethane was 813nm) were used. On both sides of the obtained base material, a dielectric multilayer film (I) was provided in the same manner as in example 1, to obtain an optical filter. The spectral transmittance of the optical filter was measured to evaluate the optical characteristics. Further, a camera module having the optical filter incorporated at the position of (B) in fig. 2 was produced using the obtained optical filter, and flare evaluation, color shading evaluation, and ghost evaluation of the camera image were performed. The results are shown in fig. 10 and table 4.

[ solution 20]

[ example 5]

Into a vessel were charged 100 parts by mass of the resin A obtained in resin Synthesis example 1, 0.30 part of the compound (A1-1), 0.10 part of the compound (A1-2), 0.70 part of the compound (A3-1), 0.40 part of the compound (A2-1), and chlorinated polyethyleneMethane, a solution (a1) having a resin concentration of 20 wt% was prepared. A resin composition (2) having the following composition was applied to a transparent glass substrate "OA-10G (thickness 150 μm)" (manufactured by Nippon electric glass (Kagaku Co., Ltd.) cut into a size of 60mm in the vertical direction and 60mm in the horizontal direction by a spin coater, and heated on a hot plate at 80 ℃ for 2 minutes to volatilize and remove the solvent. At this time, the coating conditions of the spin coater were adjusted so that the thickness after drying was 0.8 μm. Next, the solution (a1) was applied to the resin layer using an applicator under a condition that the dried film thickness was 20 μm, and the resin layer was heated on a hot plate at 80 ℃ for 5 minutes to evaporate and remove the solvent, thereby forming a transparent resin layer. Then, exposure was performed from the glass surface side using a belt type exposure machine (exposure amount 1J/cm)²Illuminance 200mW), and thereafter, calcined at 180 ℃ for 5 minutes in an oven to obtain a base material.

Next, exposure was carried out using a belt type exposure machine (exposure amount: 500 mJ/cm)²200mW), the resin composition (2) was hardened, and a base material comprising a transparent glass substrate having a transparent resin layer was obtained. On both sides of the obtained base material, a dielectric multilayer film (I) was provided in the same manner as in example 1, to obtain an optical filter. The spectral transmittance of the optical filter was measured to evaluate the optical characteristics. Further, a camera module having the optical filter incorporated at the position of (C) in fig. 2 was produced using the obtained optical filter, and flare evaluation, color shading evaluation, and ghost evaluation of the camera image were performed. The results are shown in fig. 11 and table 4.

Resin composition (2): an ethylene oxide isocyanurate-modified triacrylate (trade name: Aronix M-315, manufactured by Toyo Synthesis Chemicals, Ltd.) 30 parts, 1, 9-nonanediol diacrylate 20 parts, methacrylic acid 20 parts, glycidyl methacrylate 30 parts, 3-glycidoxypropyltrimethoxysilane 5 parts, 1-hydroxycyclohexyl benzophenone (trade name: IrGACURE)184, Ciba specialty Chemicals (manufactured by Ciba specialty Chemicals, Ltd.) 5 parts, and Mulider (San-Aid) SI-110 as a main agent (manufactured by Sanxin chemical industries, Ltd.) were mixed, dissolved in propylene glycol monomethyl ether acetate so that the solid content concentration became 50 wt%, and the resulting solution was filtered through a microfilter having a pore diameter of 0.2 μ M

[ example 6]

A base material including a transparent resin substrate was obtained in the same manner and under the same conditions as in example 1, except that in example 1, 0.04 parts of the compound (a1-1) and 0.03 parts of the compound (a1-2), 0.34 parts of the compound (A3-1) and 0.04 parts of the compound (a2-1) were used, and the thickness of the transparent resin substrate was set to 0.08 mm. On both sides of the obtained base material, a dielectric multilayer film (I) was provided in the same manner as in example 1, to obtain an optical filter. The spectral transmittance of the optical filter was measured to evaluate the optical characteristics. Further, a camera module having the optical filter incorporated at the position of (B) in fig. 2 was produced using the obtained optical filter, and flare evaluation, color shading evaluation, and ghost evaluation of the camera image were performed. The results are shown in fig. 12 and table 4.

[ example 7]

A base material including a transparent resin substrate was obtained in the same manner and under the same conditions as in example 1, except that in example 1, 0.05 part of the compound (a1-1), 0.85 part of the compound (A3-1), 0.05 part of the compound (a2-1) and the thickness of the transparent resin substrate were changed to 0.04 mm. On both sides of the obtained base material, a dielectric multilayer film (I) was provided in the same manner as in example 1, to obtain an optical filter. The spectral transmittance of the optical filter was measured to evaluate the optical characteristics. Further, a camera module having the optical filter incorporated at the position of (B) in fig. 2 was produced using the obtained optical filter, and flare evaluation, color shading evaluation, and ghost evaluation of the camera image were performed. The results are shown in fig. 13 and table 4.

[ example 8]

A resin support was produced in the same manner as in example 1, except that the resin a obtained in resin synthesis example 1 and methyl chloride were charged into a vessel to prepare a solution having a resin concentration of 20 wt%, and the obtained solution was used.

A resin layer containing a resin composition (3) having the following composition was applied to one surface of the obtained resin support by an applicator so that the thickness of the dried resin layer was 4 μm, and the resin layer was dried at 20 ℃ for 8 hours and then further dried at 100 ℃ under reduced pressure for 8 hours to obtain a substrate having a transparent resin layer containing the compound (a) and the near-infrared absorbing dye (X) on one surface of the resin support. On both sides of the obtained base material, a dielectric multilayer film (I) was provided in the same manner as in example 1, to obtain an optical filter. The spectral transmittance of the optical filter was measured to evaluate the optical characteristics. Further, a camera module having the optical filter incorporated at the position of (B) in fig. 2 was produced using the obtained optical filter, and flare evaluation, color shading evaluation, and ghost evaluation of the camera image were performed. The results are shown in fig. 14 and table 4.

Resin composition (3): resin A100 parts by mass obtained in resin Synthesis example 1, (A1-1) Compound 0.50 part, (A2-1) Compound 0.50 part, (C2-2) Compound 2.50 part, near Infrared absorbing pigment (X)1.40 part, methyl chloride (solvent, TSC: 25%)

[ example 9]

The resin composition (2) was applied to a near-infrared-absorbing glass substrate "obtained by grinding BS11 (manufactured by sonlang nit industries, Ltd.) to a thickness of 120 μm" cut into a size of 60mm in the longitudinal direction and 60mm in the transverse direction by a spin coater, and the substrate was heated on a hot plate at 80 ℃ for 2 minutes to volatilize and remove the solvent. At this time, the coating conditions of the spin coater were adjusted so that the thickness after drying was 0.8 μm. Next, a resin layer containing a resin composition (4) having the following composition was applied by an applicator so that the thickness of the dried resin layer was 4 μm, and then, exposure was carried out by using a belt type exposure machine (exposure amount: 500 mJ/cm)²200mW), the resin composition (4) was hardened, thereby obtaining a base material comprising a near infrared ray absorption glass substrate having a transparent resin layer comprising the compound (a). On both sides of the obtained base material, a dielectric multilayer film (I) was provided in the same manner as in example 1, to obtain an optical filter. The spectral transmittance of the optical filter was measured to evaluate the optical characteristics. Further, a camera module having the optical filter incorporated at the position of (B) in fig. 2 was produced using the obtained optical filter, and flare evaluation and color shading of the camera image were performedEvaluation and evaluation of ghost. The results are shown in table 4.

Resin composition (4): resin A100 parts by mass obtained in resin Synthesis example 1, (A1-1) Compound 1.00 part, (A2-1) Compound 1.00 part, (C2-2) Compound 5.00 part, methyl chloride (solvent, TSC: 25%)

[ example 10]

A base material comprising a transparent resin substrate containing the compound (a) and the near-infrared absorbing dye (X) was obtained in the same procedure and under the same conditions as in example 1, except that in example 1, 0.04 part of the compound (a1-1) and 0.03 part of the compound (a1-2), 0.14 part of the compound (A3-1), 0.04 part of the compound (a2-1) and 0.04 part of the near-infrared absorbing dye (X) were used. On both sides of the obtained base material, a dielectric multilayer film (I) was provided in the same manner as in example 1, to obtain an optical filter. The spectral transmittance of the optical filter was measured to evaluate the optical characteristics. Further, a camera module was produced using the obtained optical filter, and flare evaluation, color shading evaluation, and ghost evaluation of the camera image were performed. The results are shown in fig. 15 and table 4.

[ example 11]

A base material including a substrate made of a transparent resin was obtained in the same manner and under the same conditions as in example 1 except that in example 1, 0.04 parts of the (a1-1) compound, 0.03 parts of the (a1-2) compound, 0.34 parts of the (A3-1) compound, and 0.04 parts of the (a2-1) compound were used.

On both sides of the obtained base material, a dielectric multilayer film (I) was provided in the same manner as in example 1, to obtain an optical filter. The spectral transmittance of the optical filter was measured to evaluate the optical characteristics. Further, a camera module having the optical filter incorporated at the position of (B) in fig. 2 was produced using the obtained optical filter, and flare evaluation, color shading evaluation, and ghost evaluation of the camera image were performed. The results are shown in fig. 16 and table 4.

Comparative example 1

The same procedures and strips as in example 1 were repeated except for using 0.07 part of the compound (A1-1) and 0.08 part of the compound (A3-1) in example 1The base material including the transparent resin substrate was obtained. | X of the obtained substrate_b-X_aAnd | is 61nm and less than 100 nm.

Then, silicon dioxide (SiO) was formed on one surface of the obtained substrate₂) Layer with titanium dioxide (TiO)₂) A dielectric multilayer film (II) having a total of 26 layers formed by alternately laminating layers is formed as the dielectric multilayer film (II), and silicon dioxide (SiO) is formed on the other surface of the substrate₂) Layer with titanium dioxide (TiO)₂) The dielectric multilayer film (III) was formed by alternately laminating (20 layers in total) layers, and an optical filter having a thickness of about 0.105mm was obtained as the dielectric multilayer film (III). The dielectric multilayer film (II) and the dielectric multilayer film (III) are as shown in table 3 below.

[ Table 3]

The spectral transmittance of the obtained optical filter was measured to evaluate the optical characteristics. Further, a camera module having the optical filter incorporated at the position of (B) in fig. 2 was produced using the obtained optical filter, and flare evaluation, color shading evaluation, and ghost evaluation of the camera image were performed. The results are shown in fig. 17 and table 4. The optical filter obtained in comparative example 1 exhibited relatively good optical density and shielding performance of 700nm to 1200nm, but it was confirmed that a ghost was generated, which is considered to be caused by reflection of near infrared rays by the dielectric multilayer film included in the optical filter and reflection of the cover glass.

Comparative example 2

A base material comprising a substrate made of a transparent resin was obtained by following the same procedure and under the same conditions as in comparative example 1 except that 0.07 part of the compound (A1-1) and 0.08 part of the compound (A3-1) were used. Silica (SiO) was formed on both sides of the obtained substrate in the same order as in comparative example 1₂) Layer with titanium dioxide (TiO)₂) Dielectric multilayer film (II) having a total of 26 layers alternately stacked to obtain an optical filter having a thickness of about 0.105mmA device.

The spectral transmittance of the obtained optical filter was measured to evaluate the optical characteristics. Further, a camera module having the optical filter incorporated at the position of (B) in fig. 2 was produced using the obtained optical filter, and flare evaluation, color shading evaluation, and ghost evaluation of the camera image were performed. The results are shown in fig. 18 and table 4. In the optical filter obtained in comparative example 2, the generation of a ghost was confirmed, which is considered to be caused by the reflection of near infrared rays by the dielectric multilayer film of the optical filter and the reflection of the cover glass.

Comparative example 3

A base material including a transparent resin substrate was obtained by the same procedure and conditions as in comparative example 1. Then, a dielectric multilayer film (I) was formed on both surfaces of the obtained substrate in the same procedure and under the same conditions as in example 11, and further the same dielectric multilayer film (I) was formed on the other surface of the substrate, thereby obtaining an optical filter having a thickness of about 0.101 mm.

The spectral transmittance of the obtained optical filter was measured to evaluate the optical characteristics. Further, a camera module having the optical filter incorporated at the position of (B) in fig. 2 was produced using the obtained optical filter, and flare evaluation, color shading evaluation, and ghost evaluation of the camera image were performed. The results are shown in fig. 19 and table 4. In the optical filter obtained in comparative example 3, the absorption in the near infrared wavelength region was insufficient, the flare suppressing effect was poor, and the generation of a ghost was confirmed, which is considered to be caused by the reflection of the near infrared ray and the reflection of the cover glass by the dielectric multilayer film included in the optical filter.

The composition of the base material, the symbols of the various compounds, and the drying conditions of the film [ (transparent) resin substrate or resin support ] in table 4 are as follows.

< form of base Material >

Form (1): transparent resin substrate containing compound (A)

Form (2): having a resin layer on both surfaces of a transparent resin substrate containing a compound (A)

Form (3): having a transparent resin layer containing a compound (A) on both sides of a resin support

Form (4): a transparent resin layer containing a compound (A) on one surface of a transparent glass substrate

Form (5): a transparent resin layer containing a compound (A) on one surface of a near-infrared-absorbing glass substrate

Form (6): having an antireflection layer on both surfaces of a transparent resin substrate containing a compound (A)

Form (7): transparent resin substrate comprising compound (A) and near-infrared absorbing dye (X)

Form (8): in a composition comprising compound (A) and | X_b-X_aBoth surfaces of a transparent resin substrate having | < 100nm has a near-infrared reflecting layer (comparative example)

Form (9): in a composition comprising compound (A) and | X_b-X_aHaving antireflection layers on both surfaces of a transparent resin substrate having | < 100nm (comparative example)

Form (10): comprising a compound (A) and | X_b-X_aSubstrate made of transparent resin having | < 100nm (comparative example)

< glass substrate >

Glass substrate (1): a transparent glass substrate "OA-10G (thickness 150 μm)" cut into a size of 60mm in length and 60mm in width (manufactured by Nippon electric glass laboratory Co., Ltd.)

Glass substrate (2): a near-infrared-absorbing glass substrate cut into a size of 60mm in the longitudinal direction and 60mm in the transverse direction was prepared by grinding BS-11 (manufactured by Songlanzi industries, Ltd.) to a thickness of 120 μm "

< support made of resin >

Resin support (1): transparent resin substrate comprising resin A and having a thickness of 0.1mm, a vertical length of 60mm and a horizontal length of 60mm

< near Infrared absorbing dye >

Compound (A)

Compound (A1-1): a compound represented by the formula (A1-1) (absorption maximum wavelength in methylene chloride: 712nm)

Compound (A1-2): a compound represented by the formula (A1-2) (absorption maximum wavelength in methylene chloride 686nm)

Compound (A3-1): a compound represented by the formula (A3-1) (absorption maximum wavelength in methylene chloride: 738nm)

Compound (A2-1): a compound represented by the formula (A2-1) (absorption maximum wavelength in methylene chloride of 776nm)

Compound (C2-2): a compound represented by the formula (C2-2) (absorption maximum wavelength in methylene chloride of 760nm)

Other pigments (X)

Near infrared absorbing dye (X): a compound represented by the formula (X) (absorption maximum wavelength in methylene chloride of 813nm)

< solvent >

Solvent (1): chlorinated methanes

< conditions for drying film >

Condition (1): 20 ℃/8hr → 100 ℃/8hr under reduced pressure

Claims

1. A camera module, comprising:

an optical lens group disposed on the incident side of light;

a cover glass having a near-infrared light reflecting section that reflects light in a near-infrared region;

an image pickup element that receives light incident through the optical lens group; and

a near-infrared light absorbing part absorbing light in the near-infrared region, and

the near-infrared light absorbing portion includes an optical filter including a cycloolefin resin having a refractive index of 1.52 or more and less than 1.54, and a near-infrared light absorbing compound.

2. The camera module according to claim 1, wherein a cover glass having the near-infrared light reflecting portion and the near-infrared light absorbing portion are arranged with the near-infrared light reflecting portion and the near-infrared light absorbing portion in this order from an incident side of light.

3. The camera module according to claim 1 or 2, wherein the cover glass having the near-infrared light reflecting portion includes: a glass substrate; an anti-reflection layer on at least one side of the glass substrate and preventing reflection of light in a visible region; and a reflective layer which is located on at least one surface of the glass substrate and reflects light in a near infrared region.

4. The camera module according to claim 1 or 2, wherein the near-infrared light absorbing portion is a dispersion of the compound in the cyclic olefin resin.

5. The camera module according to claim 1 or 2, wherein the near-infrared light absorbing portion has an antireflection layer that prevents reflection of light in a visible light region on an incident surface of light.

6. The camera module according to claim 1 or 2, wherein the camera module satisfies a condition (1), a condition (2) shown below,

condition (1) R_NIR-5＜30

Condition (2) R_NIR-30＜30

Here, the number of the first and second electrodes,

R_NIR-5：

RA5(λ): reflectance at wavelength λ nm when incident at 5 degrees from the optical lens group side to the optical filter

RB5(λ): a reflectance at a wavelength λ nm when the light is incident on the cover glass at 5 degrees from the optical lens group side,

R_NIR-30：

RA30(λ): reflectance at wavelength λ nm when incident at 30 degrees from the optical lens group side to the optical filter

RB30(λ): and a reflectance at a wavelength λ nm when the light is incident on the cover glass at 30 degrees from the optical lens group side.

7. The camera module according to claim 1 or 2, which satisfies the following condition (3), condition (4),

condition (3) T_NIR-5＜30

Condition (4) T_NIR-30＜30

Here, the number of the first and second electrodes,

T_NIR-5：

TA5(λ): transmittance at wavelength λ nm when the light enters the optical filter at 5 degrees from the optical lens group side

TB5(λ): a transmittance at wavelength λ nm when the light enters the cover glass at 5 degrees from the side opposite to the optical lens group,

T_NIR-30：

TA30(λ): transmittance at wavelength λ nm when incident light is incident on the optical filter at 30 degrees from the optical lens group side

TB30(λ): and a transmittance at a wavelength of λ nm when the light enters the cover glass at 30 degrees from a surface side opposite to the optical lens group side.

8. The camera module according to claim 1 or 2, wherein the near-infrared ray absorbing compound is at least one compound selected from the group consisting of a squarylium compound, a phthalocyanine compound, a naphthalocyanine compound, a ketanium compound, and a cyanine compound.

9. The camera module in accordance with claim 1 or 2, wherein the optical filter has a maximum absorption wavelength in a wavelength region of 650nm to 800 nm.

10. The camera module according to claim 1 or 2, wherein the optical filter contains a compound having an absorption maximum wavelength in a region of a wavelength of 650nm or more and 800nm or less, the compound having an absorption maximum wavelength in a region of a wavelength of 650nm or more and 715nm or less is a squarylium-based compound, the compound having an absorption maximum wavelength in a region of a wavelength of more than 715nm and 750nm or less is a phthalocyanine-based compound, and the compound having an absorption maximum wavelength in a region of a wavelength of more than 750nm and 800nm or less is a squarylium-based compound.

11. An electronic device having a camera module as claimed in any one of claims 1 to 10.