CN113259557A

CN113259557A - Ultraviolet image sensor and ultraviolet imaging device

Info

Publication number: CN113259557A
Application number: CN202110498546.4A
Authority: CN
Inventors: 潘小永; 郝英俊; 宋力帆
Original assignee: Beijing Best Color Technology Co ltd
Current assignee: Beijing Best Color Technology Co ltd
Priority date: 2021-05-08
Filing date: 2021-05-08
Publication date: 2021-08-13
Anticipated expiration: 2041-05-08
Also published as: CN113259557B

Abstract

The present invention provides an ultraviolet image sensor, comprising: a pixel cell array composed of a plurality of pixel cells: the pixel unit includes: a first pixel detecting an ultraviolet UVA band and a second pixel detecting an ultraviolet UVB band. According to the invention, the acquisition of the ultraviolet UVA image and the ultraviolet UVB image can be respectively realized through one ultraviolet image sensor.

Description

Ultraviolet image sensor and ultraviolet imaging device

Technical Field

The application relates to the technical field of image sensors, in particular to an ultraviolet image sensor and an ultraviolet imaging device.

Background

With the intensive research on ultraviolet related technologies, ultraviolet imaging technologies are gradually widely used. If in the field of makeup, the smearing condition of the sunscreen cream can be observed through ultraviolet imaging, and then whether the sunscreen cream is effective or not and whether the sunscreen cream needs to be applied again or not can be effectively judged. In the prior art, ultraviolet wave bands collected by each pixel of an ultraviolet image sensor are the same, and finally, an ultraviolet image is presented through a gray level image. However, since the sunscreens which function as sunscreens in the sunscreen cream are classified into UVA sunscreens and UVB sunscreens, if all pixels collect the same ultraviolet band, for example, collect ultraviolet light with a wavelength band centered at 365nm, the sunscreen effects of the UVA sunscreens and the UVB sunscreens in the sunscreen cream cannot be separately determined.

Therefore, the ultraviolet image sensor in the prior art has a problem that the UVA image and the UVB image cannot be acquired separately.

Disclosure of Invention

In order to solve the problem that an ultraviolet image sensor in the prior art cannot respectively acquire a UVA image and a UVB image, the invention provides the ultraviolet image sensor capable of respectively acquiring the UVA image and the UVB image.

In order to achieve the above object, an aspect of the present invention provides an ultraviolet image sensor including: a pixel cell array composed of a plurality of pixel cells: the pixel unit includes: a first pixel detecting an ultraviolet UVA band and a second pixel detecting an ultraviolet UVB band.

Preferably, the area of the second pixel is greater than or equal to the area of the first pixel.

Preferably, in the pixel unit, the number of the first pixels and the number of the second pixels are both one.

As a preferred technical solution, the pixel unit is a square, and if the pixel unit is divided into four square regions with equal areas according to midpoints of four sides of the pixel unit, the first pixel coincides with one of the square regions; the region of the pixel unit other than the first pixel coincides with the second pixel.

As a preferred technical solution, the ultraviolet image sensor further includes: a first microlens disposed over the first pixel; a second microlens disposed over the second pixel.

As a preferred technical solution, the ultraviolet image sensor further includes: a first microlens disposed over the first pixel; the second micro-lenses and the first micro-lenses have the same area and the same shape, and the three second micro-lenses are arranged on the second pixels in a non-overlapping mode.

Preferably, the ultraviolet image sensor is a front-illuminated CMOS image sensor or a back-illuminated CMOS image sensor.

As a preferable technical solution, the first pixel includes: the light transmission waveband of the first filter layer is an ultraviolet UVA waveband; the second pixel includes: and the light transmission waveband of the second filter layer is an ultraviolet UVB waveband.

As a preferred technical solution, the ultraviolet image sensor further includes: the third filter layer is arranged on the pixel unit array, and light transmission wave bands of the third filter layer are ultraviolet UVA wave bands and ultraviolet UVB wave bands; the first pixel includes: the fourth filter layer is used for filtering ultraviolet UVB wave band light; the second pixel includes: and the fifth filter layer is used for filtering ultraviolet UVA wave band light rays.

On the other hand, the invention further provides an ultraviolet imaging device, which comprises a lens module, an ultraviolet light supplement lamp, an image processing unit and the ultraviolet image sensor according to any one of the above technical schemes, wherein the light supplement waveband of the ultraviolet light supplement lamp comprises an ultraviolet light UVA waveband and an ultraviolet light UVB waveband.

Drawings

FIG. 1 shows a schematic diagram of an ultraviolet image sensor pixel cell in accordance with an embodiment of the invention;

FIG. 2 shows a schematic diagram of an array of UV image sensor pixel cells according to an embodiment of the invention;

FIG. 3 shows a schematic diagram of an ultraviolet image sensor pixel cell of another embodiment of the invention;

FIG. 4-1 shows a cross-sectional view corresponding to position A-A' in FIG. 3 in one embodiment;

FIG. 4-2 shows a cross-sectional view corresponding to position B-B' in FIG. 3 in one embodiment;

FIGS. 4-3 illustrate cross-sectional views corresponding to the position A-A' in FIG. 3 in another embodiment;

FIGS. 4-4 show cross-sectional views corresponding to positions B-B' of FIG. 3 in another embodiment;

FIG. 5 shows a schematic diagram of an ultraviolet image sensor pixel cell of another embodiment of the invention;

FIG. 6-1 shows a cross-sectional view corresponding to the position C-C' in FIG. 5 in one embodiment;

FIG. 6-2 shows a cross-sectional view corresponding to the position D-D' in FIG. 5 in one embodiment;

FIGS. 6-3 illustrate a cross-sectional view corresponding to the position C-C' in FIG. 5 in another embodiment;

FIGS. 6-4 show cross-sectional views corresponding to the D-D' position of FIG. 5 in another embodiment;

wherein the figures include the following reference numerals:

101. a first pixel; 102. a second pixel; 301. a first microlens; 302. a second microlens; 401. a first filter layer; 402. a second filter layer; 403. a metal wiring layer; 404. a photoelectric conversion layer; 405. and (4) isolating the groove.

Detailed Description

The technical solution in the embodiments of the present invention will be described in detail below with reference to the drawings in the embodiments of the present invention. It is to be understood that the described embodiments are merely a few embodiments of the invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments according to the present application. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, and it should be understood that when the terms "comprises" and/or "comprising" are used in this specification, they specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof, unless the context clearly indicates otherwise.

The relative arrangement of the components and steps, the numerical expressions and numerical values set forth in these embodiments do not limit the scope of the present invention unless specifically stated otherwise. Meanwhile, it should be understood that the sizes of the respective portions shown in the drawings are not drawn in an actual proportional relationship for the convenience of description. Techniques, methods, and apparatus known to those of ordinary skill in the relevant art may not be discussed in detail but are intended to be part of the specification where appropriate. In all examples shown and discussed herein, any particular value should be construed as merely illustrative, and not limiting. Thus, other examples of the exemplary embodiments may have different values. It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, further discussion thereof is not required in subsequent figures.

As shown in fig. 1 and 2, an ultraviolet image sensor includes: a pixel cell array composed of a plurality of pixel cells: the pixel unit includes: a first pixel 101 detecting the UVA band of ultraviolet light and a second pixel 102 detecting the UVB band of ultraviolet light. The shapes and distributions of the first pixel 101 and the second pixel 102 in fig. 1 and 2 are merely exemplary and should not be construed as necessarily limiting the shape or structure.

In each pixel unit, the number of the first pixels 101 may be one or more, and the number of the second pixels 102 may be one or more. When the ultraviolet image sensor performs image acquisition, an UVA image is formed by pixel values acquired by all or a part of the first pixels 101, and an UVB image is formed by pixel values acquired by all or a part of the second pixels 102. According to the scheme, the ultraviolet image sensor is used for respectively acquiring the UVA image and the UVB image, the camera is prevented from being additionally arranged on the imaging equipment, and the space is saved. Furthermore, under a specific scene, such as a sun-proof scene, a user can respectively observe the protection condition of the sun-proof cream on ultraviolet rays in UVA wave band and ultraviolet rays in UVB wave band through UVA images and UVB images.

It should be noted that the principle of collecting an image by the ultraviolet image sensor is that each first pixel 101 and each pixel 102 respectively receive the intensity of ultraviolet light of a corresponding waveband irradiated thereon, and convert the intensity into an electrical signal with a corresponding size, and finally convert the electrical signal into a luminance value or a gray value corresponding to the pixel.

Optionally, in each pixel unit, the area of the second pixel 102 is greater than or equal to the area of the first pixel 101. The area of the second pixel 102 or the first pixel 101 refers to the area of the surface on the side receiving light. The larger the area receiving light for each pixel, the more sensitive it is. Since the image sensor has a lower sensitivity to ultraviolet rays in the UVB band than that of ultraviolet rays in the UVA band, setting the area of the second pixel 102 in the pixel unit to be larger than that of the first pixel 101 can relatively enhance the sensitivity of the ultraviolet image sensor to ultraviolet rays in the UVB band.

Optionally, in the pixel unit, the number of the first pixels 101 and the number of the second pixels 102 are both one. I.e. the number of pixel units in the uv image sensor is the same as the number of pixels of the obtained uv image. If the ultraviolet image sensor includes 100 ten thousand pixel units, the resulting UVA image and UVB image are both 100 ten thousand pixel images.

Alternatively, in order to increase the number of pixels of the UVA image or the UVB image, the number of first pixels 101 in a pixel unit may be set to be plural, or the number of second pixels 102 in a pixel unit may be set to be plural. Further, more pixel values can be obtained through calculation of a neighborhood interpolation algorithm.

Optionally, the pixel unit is square, and if the pixel unit is divided into four square regions with equal areas according to midpoints of four sides of the pixel unit, the first pixel 101 coincides with one of the square regions; the region other than the first pixel 101 in the pixel unit overlaps with the second pixel 102. The area ratio and the structural arrangement of the first pixel 101 and the second pixel 102 shown in fig. 1 are one of the arrangement forms of the above schemes, in fig. 1, the first pixel 101 is arranged at the upper left portion of the pixel unit, and optionally, the first pixel 101 may also be arranged at the upper right portion, the lower left portion, the lower right portion, and the like of the pixel unit. In the prior art, the shape of the pixels of the main image sensor is square, so the structural arrangement of the pixels is more consistent with the production process of the image sensor, and the increase of the production cost is avoided to a certain extent.

Optionally, as shown in fig. 3, the ultraviolet image sensor further includes: a first microlens 301, wherein the first microlens 301 is disposed above the first pixel 101; a second microlens 302, wherein the second microlens 302 is disposed above the second pixel 302.

It should be noted that the micro lens functions to converge light onto each pixel structure, so as to improve the light-sensing capability of the image sensor. In the above embodiment, the second microlens 302 is a microlens covering the entire surface area of the second pixel 102, so that the ultraviolet light irradiated to the surface area of the second pixel 102 can be better converged into the second pixel 102.

In a specific embodiment, the ultraviolet image sensor as shown in fig. 3 may be a front-illuminated image sensor. As shown in fig. 4-1 and 4-2, the first pixel 101 includes a first microlens 301, a first filter layer 401 disposed adjacent to the first microlens 301 in the light emitting direction, wherein the light transmitting waveband of the first filter layer 401 is an ultraviolet UVA waveband, a metal circuit layer 403 disposed on a side of the first filter layer 401 away from the first microlens 301, and a photoelectric conversion layer 404 disposed on a side of the metal circuit layer 403 away from the first filter layer 401. The second pixel 102 includes a second microlens 302, a second filter layer 402 disposed adjacent to the second microlens 302 in the light emitting direction, wherein the light transmitting waveband of the second filter layer 402 is an ultraviolet UVB waveband, a metal circuit layer 403 disposed on a side of the second filter layer 402 away from the second microlens 302, and a photoelectric conversion layer 404 disposed on a side of the metal circuit layer 403 away from the second filter layer 402. The first pixel 101 and the second pixel 102 correspond to different photoelectric conversion layers 404, and an isolation groove 405 is disposed between the first pixel and the second pixel to prevent crosstalk of light between the pixels.

In a specific embodiment, the ultraviolet image sensor as shown in fig. 3 may be a back-illuminated image sensor. As shown in fig. 4-3 and 4-4.

Optionally, as shown in fig. 5, the ultraviolet image sensor further includes: a first microlens 301, wherein the first microlens 301 is disposed on the first pixel 101; three second microlenses 302, the second microlenses 302 have the same area and the same shape as the first microlenses 301, and the three second microlenses 302 are disposed on the second pixels 102 without overlapping.

The microlens is manufactured by using a photoresist thermal reflow technique or a laser direct writing technique as an optical technique, and in the prior art, for example, the micro-projection mirrors of the micro-projection mirror array on the color image sensor have the same area and the same shape. Therefore, the above embodiment can avoid an additional complicated microlens processing flow while ensuring that the ultraviolet light on the second pixel 102 is effectively converged.

In particular embodiments, the ultraviolet image may be a front-illuminated image sensor, as shown in FIG. 5, as shown in FIGS. 6-1 and 6-2, or a back-illuminated image sensor, as shown in FIGS. 6-3 and 6-4.

The invention also provides an ultraviolet imaging device, which comprises a lens module, an ultraviolet light supplement lamp, an image processing unit and the ultraviolet image sensor in any one of the technical schemes, wherein the light supplement waveband of the ultraviolet light supplement lamp comprises an ultraviolet UVA waveband and an ultraviolet UVB waveband.

It is to be understood that the present invention is generally directed to the use of directional terms such as "front, rear, upper, lower, left, right", "transverse, vertical, horizontal" and "top, bottom" or the like, which are used herein for the purpose of describing particular embodiments of the present invention only and are not intended to limit the scope of the present invention, since the directional terms are not used to indicate and imply that the apparatus or components so referred to must have a particular orientation or be constructed and operated in a particular orientation; the terms "inner and outer" refer to the inner and outer relative to the profile of the respective component itself.

Spatially relative terms such as "above … …", "above … …", "above … …", "above", and the like may be used herein for ease of description to describe the spatial relationship of one device or feature to another device or feature as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if a device in the figures is turned over, devices described as "above" or "on" other devices or configurations would then be oriented "below" or "under" the other devices or configurations. Thus, the exemplary term "above … …" can include both an orientation of "above … …" and "below … …". The device may be otherwise variously oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

It should be noted that the terms "first", "second", and the like are used to define the components, and are only used to distinguish the corresponding components, if not to distinguish them.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. An ultraviolet image sensor, comprising: a pixel cell array composed of a plurality of pixel cells:

the pixel unit includes: a first pixel detecting an ultraviolet UVA band and a second pixel detecting an ultraviolet UVB band.

2. The ultraviolet image sensor of claim 1, wherein the area of the second pixel is greater than or equal to the area of the first pixel.

3. The ultraviolet image sensor as claimed in claim 2, wherein the number of the first pixels and the second pixels in the pixel unit is one.

4. The ultraviolet image sensor according to claim 3, wherein the pixel unit is square, and if the pixel unit is divided into four square regions with equal areas according to midpoints of four sides of the pixel unit, the first pixel coincides with one of the square regions;

the region of the pixel unit other than the first pixel coincides with the second pixel.

5. The ultraviolet image sensor as set forth in claim 4, further comprising:

a first microlens disposed over the first pixel;

a second microlens disposed over the second pixel.

6. The ultraviolet image sensor as set forth in claim 4, further comprising:

a first microlens disposed over the first pixel;

the second micro-lenses and the first micro-lenses have the same area and the same shape, and the three second micro-lenses are arranged on the second pixels in a non-overlapping mode.

7. The ultraviolet image sensor of claim 6, wherein the ultraviolet image sensor is a front-illuminated CMOS image sensor or a back-illuminated CMOS image sensor.

8. The ultraviolet image sensor of claim 1, wherein the first pixel comprises: the light transmission waveband of the first filter layer is an ultraviolet UVA waveband;

the second pixel includes: and the light transmission waveband of the second filter layer is an ultraviolet UVB waveband.

9. The ultraviolet image sensor as set forth in claim 1, further comprising:

the third filter layer is arranged on the pixel unit array, and light transmission wave bands of the third filter layer are ultraviolet UVA wave bands and ultraviolet UVB wave bands;

the first pixel includes: the fourth filter layer is used for filtering ultraviolet UVB wave band light;

the second pixel includes: and the fifth filter layer is used for filtering ultraviolet UVA wave band light rays.

10. An ultraviolet imaging apparatus, comprising: the lens module, the ultraviolet fill-in light lamp, the image processing unit and the ultraviolet image sensor as claimed in any one of claims 1 to 9, wherein a fill-in light band of the ultraviolet fill-in light lamp includes an ultraviolet UVA band and an ultraviolet UVB band.