CN113671618A

CN113671618A - Phase plate, camera module and mobile terminal

Info

Publication number: CN113671618A
Application number: CN202110930285.9A
Authority: CN
Inventors: 谭耀成; 韦怡; 陈嘉伟; 张海裕; 高玉婵; 吴青峻; 李响
Original assignee: Guangdong Oppo Mobile Telecommunications Corp Ltd
Current assignee: Guangdong Oppo Mobile Telecommunications Corp Ltd
Priority date: 2021-08-13
Filing date: 2021-08-13
Publication date: 2021-11-19
Also published as: WO2023016127A1

Abstract

The application relates to a phase plate, a camera module and a mobile terminal, wherein the phase plate comprises a shading piece, and the shading piece is arranged on the phase plate to form a shading area; the phase plate is provided with a light-transmitting area, the light-shielding area surrounds the light-transmitting area, and the light-transmitting area is provided with a diffraction microstructure which modulates the phase of light when the light penetrates through the light-transmitting area. The application discloses phase place board is including the piece that shades to shading area encircles the light-passing region in order to form aperture diaphragm effect, thereby can increase the depth of field when light pierces through light-passing region back formation of image, and the diffraction microstructure that can utilize the phase place board simultaneously comes to carry out phase modulation to the light again, thereby can increase the depth of field when shooing, improves the shooting effect.

Description

Phase plate, camera module and mobile terminal

Technical Field

The application relates to the technical field of computers, in particular to a phase plate, a camera module and a mobile terminal.

Background

With the increasing requirements of consumers on the photographing function of mobile terminals such as mobile phones, tablet computers and smart watches, various mobile terminals on the market are equipped with image acquisition devices such as cameras.

However, when the mobile terminal shoots, the mobile terminal can image an object with high magnification, but the disadvantage is that the depth of field is very small during imaging, and particularly when an uneven object is shot, some areas in the shot image are clear and some areas are blurred, so that the depth of field is small.

Disclosure of Invention

The embodiment of the application provides a phase plate, a camera module and a mobile terminal, and can realize the aperture diaphragm effect, thereby increasing the depth of field of imaging.

The phase plate comprises a light shading piece, wherein the light shading piece is arranged on the phase plate to form a light shading area; the phase plate is provided with a light-transmitting area, the light-shielding area surrounds the light-transmitting area, and the light-transmitting area is provided with a diffraction microstructure which modulates the phase of light when the light penetrates through the light-transmitting area.

In one embodiment, the phase plate further includes a light-transmissive substrate, the diffractive microstructure is disposed on one side of the light-transmissive substrate, and the light-shielding member covers the light-transmissive substrate and/or the diffractive microstructure to form the light-shielding region in the phase plate.

In one embodiment, the phase plate further comprises a antireflection film covering the light-transmitting substrate and/or the diffractive microstructures in the light-transmitting region and covering the light-transmitting substrate in the light-shielding region.

In one embodiment, the antireflection film includes a plurality of silica sub-films and a plurality of titania sub-films, the silica sub-films and the titania sub-films being alternately stacked on each other.

In one embodiment, the silica sub-film and the titania sub-film have 7 layers, and the 1 st layer to the 7 th layer are sequentially: a silica sub-film, a titania sub-film, and a silica sub-film.

In one embodiment, the light shield includes a single chromium sub-film, a multi-layer silicon dioxide sub-film, and a multi-layer chromium oxide sub-film, which are stacked; the single-layer chromium sub-film is arranged on the central layer of the light shading part, the two side faces of the single-layer chromium sub-film respectively comprise a plurality of layers of silicon dioxide sub-films and chromium sesquioxide sub-films which are alternately stacked, and the sub-films arranged on the two side faces of the single-layer chromium sub-film are arranged in a mirror image mode.

In one embodiment, the single-layer chromium sub-film, the multi-layer silicon dioxide sub-film and the multi-layer chromium oxide sub-film comprise 21 layers, and the 1 st layer to the 21 st layer are sequentially: a silicon dioxide sub-film, a chromium oxide sub-film, a chromium oxide sub-film, a silicon dioxide sub-film, a chromium oxide sub-film, and a silicon dioxide sub-film.

In one embodiment, the thickness of the light-transmitting substrate ranges from 0.15mm to 1.5mm, and the height of the diffraction microstructure in the thickness direction of the light-transmitting substrate ranges from 2 μm to 20 μm.

In one embodiment, the transparent substrate is made of glass, or the transparent substrate is made of resin.

In one embodiment, a side of the light-transmitting substrate facing away from the diffractive microstructure is planar or spherical.

In one embodiment, the surface of the phase plate perpendicular to the optical axis is circular or square.

A camera module comprises a photosensitive element, an optical filter and a plurality of lenses, and further comprises the phase plate; the phase plate, the lenses, the optical filter and the photosensitive element are sequentially arranged along the same optical axis direction, and the phase plate, the lenses and the optical filter are all located on the photosensitive side of the photosensitive element.

A mobile terminal comprises the camera module.

Above-mentioned phase place board, camera module and mobile terminal, the phase place board includes the light-shading piece, and the light-shading piece is located on the phase place board in order to form the light-shading region to the light-shading region encircles the light-passing region and forms the aperture diaphragm effect, thereby can increase the depth of field when light penetrates light-passing region back formation of image. Meanwhile, the diffraction microstructure of the phase plate can be used for carrying out phase modulation on the light, so that the depth of field during shooting can be increased, and the shooting effect is improved.

Drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

Fig. 1 is a schematic structural diagram of a mobile terminal in one embodiment;

fig. 2 is a schematic structural diagram of a camera module in one embodiment;

FIG. 3 is a schematic diagram of the phase plate according to an embodiment;

fig. 4 is a schematic structural view of a phase plate in another embodiment;

fig. 5 is a schematic structural view of a phase plate in another embodiment;

fig. 6 is a schematic structural view of a phase plate in another embodiment;

fig. 7 is a schematic structural view of a phase plate in another embodiment;

fig. 8 is a schematic structural view of a phase plate in another embodiment;

fig. 9 is a schematic view of a phase plate according to another embodiment;

fig. 10 is a schematic view of a phase plate according to another embodiment;

fig. 11 is a schematic view of a phase plate according to another embodiment;

FIG. 12 is a schematic diagram illustrating the effect of a light shield in one embodiment;

FIG. 13 is a schematic illustration of the antireflective effect of the light shield and antireflective film in one embodiment;

FIG. 14 is a flow chart of a method of fabricating a phase plate according to an embodiment;

fig. 15 is a schematic structural diagram of a mobile terminal according to an embodiment of the present application.

Detailed Description

In order to make the objects, technical solutions and advantages of the present application more apparent, the present application is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present application and are not intended to limit the present application.

It will be understood that, as used herein, the terms "first," "second," and the like may be used herein to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish one element from another. For example, a first region may be termed a second region, and, similarly, a second region may be termed a first region, without departing from the scope of the present application. The first region and the second region are both regions, but they are not the same region.

As used herein, "terminal device" refers to a device capable of receiving and/or transmitting communication signals including, but not limited to, devices connected via any one or more of the following connections:

(1) via wireline connections, such as via Public Switched Telephone Network (PSTN), Digital Subscriber Line (DSL), Digital cable, direct cable connections;

(2) via a Wireless interface means such as a cellular Network, a Wireless Local Area Network (WLAN), a digital television Network such as a DVB-H Network, a satellite Network, an AM-FM broadcast transmitter.

A terminal device arranged to communicate over a wireless interface may be referred to as a "mobile terminal". Examples of mobile terminals include, but are not limited to, the following electronic devices:

(1) satellite or cellular telephones;

(2) personal Communications Systems (PCS) terminals that may combine cellular radiotelephones with data processing, facsimile, and data Communications capabilities;

(3) radiotelephones, pagers, internet/intranet access, Web browsers, notebooks, calendars, Personal Digital Assistants (PDAs) equipped with Global Positioning System (GPS) receivers;

(4) conventional laptop and/or palmtop receivers;

(5) conventional laptop and/or palmtop radiotelephone transceivers, and the like.

Referring to fig. 1, in some embodiments, the mobile terminal 10 is a smart phone, and the mobile terminal 10 includes a camera module 100 and a housing 200, where the camera module 100 is disposed on the housing 200. The camera module 100 can be used to perform a photographing function. For example, in some embodiments, the camera module 100 can perform the function of a front camera, and a user can perform operations such as self-shooting, video call, and the like through the camera module 100. In other embodiments, the camera module 100 can perform a function of a rear camera, and a user can perform operations such as macro shooting and video recording through the camera module 100. In other embodiments, the mobile terminal 10 may be a tablet computer, a notebook computer, or the like. The present application takes the camera module 100 of a smart phone as an example for description, but it should be understood that the camera module 100 disclosed in the present application is also applicable to other types of mobile terminals 10.

Referring to fig. 2, the camera module 100 includes a photosensitive element 208, a filter 206, a plurality of lenses 204, and a phase plate 202; the phase plate 202, the lenses 204, the filters 206 and the photosensitive elements 208 are sequentially arranged along the same optical axis direction, and the phase plate 202, the lenses 204 and the filters 206 are all located on the photosensitive side of the photosensitive elements 208. The number of the lenses 204 may be set as required, for example, the number of the lenses 204 may be 2 or more than 2, for example, 4 lenses are provided in the camera module 110 shown in fig. 2. In other embodiments, 5 or 6 lenses can be arranged in the camera module.

It is noted that the lens 112 may be a convex lens having a positive refractive power or a concave lens having a negative refractive power. The number and arrangement of the lenses 112 in the camera module can be adjusted as long as the camera module can meet the corresponding shooting requirements. Taking 4 lenses 112 in the camera module as an example, in the direction from the object side to the image side, a first lens, a second lens, a third lens and a fourth lens are sequentially arranged in the camera module along the optical axis direction, wherein the first lens and the third lens have positive refractive power, and the second lens and the fourth lens have negative refractive power. The filter 206 may be an infrared cut filter (IRCF, IR filter).

It should be noted that the photosensitive element 208 is disposed along the optical axis direction of the lens 204, and the phase plate 202 and the plurality of lenses 204 are both located on the photosensitive side of the photosensitive element 208, so that the external light enters the photosensitive element 208 to be imaged after passing through the phase plate 202 and the plurality of lenses 204.

Types of light sensing elements 208 may include CCD (charge coupled) elements, CMOS (complementary metal oxide conductor) devices, photodiodes, and the like. The light sensing elements 208 may be color light sensors, monochromatic light sensors, infrared light sensors, grayscale sensors, and the like, divided by color. The camera module 110 is used for processing light, so that the processed light enters the photosensitive element 208 to meet the imaging requirement of the photosensitive element 208. The photosensitive element 208 may be integrated on the circuit board in a patch manner, and the optical filter 206 may be disposed between the camera module 110 and the photosensitive element 208, so as to filter out infrared light that adversely affects the imaging effect by using the optical filter 206.

There are many possibilities for the position of the phase plate 202 in the camera module 110, and specifically, the phase plate 202 may be disposed between two adjacent lenses 204, or disposed on one side of all the lenses, but is not limited thereto.

The camera module 100 may be a macro lens module, an ultra-micro lens module, a telephoto lens module, a wide-angle lens module, etc., and is not limited herein. The macro lens module and the ultra-macro lens module are both used as special lenses for macro photography and are mainly used for shooting very fine objects such as flowers, insects and the like. The long focal length lens module is a photographing lens having a focal length longer than that of a standard lens. The wide-angle lens module is a photographic lens with a focal length shorter than that of a standard lens, a visual angle larger than that of the standard lens, a focal length longer than that of a fisheye lens and a visual angle smaller than that of the fisheye lens. The distance between the shooting object and the lens is less than 1cm (centimeter), and the lens capable of amplifying the object by more than 30 times is an ultra-micro distance lens module.

The camera module comprises a phase plate with an aperture diaphragm effect, and the dispersion degree of imaging is controlled through the phase plate, so that the depth of field of imaging can be improved. The phase plate can well control the deviation and dispersion degree of the imaging object distance relative to the optimal object distance by adopting a Point Spread Function (PSF), namely the imaging definition of the scenery in a long range before and after the optimal imaging object distance is close, namely the imaging depth of field is increased. Among them, in the optical system, when an input object is a point light source, the light field distribution of an output image thereof is referred to as a point spread function, and also referred to as a point spread function.

Furthermore, the mobile terminal can also combine an image processing algorithm to generate an image with a larger imaging definition range, so that a clear image can be obtained at a higher probability, and the definition and accuracy of the image shot by the camera module are improved. The image processing algorithm includes, but is not limited to, a subject recognition algorithm, a face detection algorithm, a beauty algorithm, a pixel interpolation algorithm, a deconvolution or deep learning algorithm, and the like.

Fig. 3 is a schematic illustration of a cross-section of a phase plate in an embodiment. As shown in fig. 3, the phase plate 202 includes a light shielding member 304, the light shielding member 304 is disposed on the phase plate 202 to form a light shielding region; the phase plate 202 has a light-transmitting area, a light-shielding area surrounding the light-transmitting area, and the light-transmitting area has a diffractive microstructure 302, and when light passes through the light-transmitting area, the diffractive microstructure 302 modulates the phase of the light.

The light blocking member 304 is a member for blocking light. The light-shielding member 304 may specifically be a light-shielding film, a light-shielding plate, a light-shielding cloth, or the like, without being limited thereto. If the light-shielding member 304 is a light-shielding film, the light-shielding film is coated on the phase plate 202; if the light-shielding member 304 is a light-shielding plate or a light-shielding cloth, the light-shielding plate or the light-shielding cloth is attached to the phase plate 202. The light-shielding member 304 is disposed on the phase plate 202, and a region of the phase plate 202 shielded by the light-shielding member 304 is a light-shielding region.

The light passing area is the area in the phase plate 202 through which light can pass. The light-transmitting region and the light-blocking region do not overlap with each other, and the light-transmitting region and the light-blocking region may form the entire region of the phase plate 202. The size of the light transmission region can be set as needed. For example, the size of the light transmission region may be a square with a side of 1.1mm (millimeter), a circle with a radius of 2.2mm, or the like, but is not limited thereto.

It is understood that the two side surfaces of the phase plate perpendicular to the optical axis direction have light-passing regions, and the light-shielding region surrounds the light-passing regions, and surrounds the light-passing regions on one side surface, or surrounds the light-passing regions on both side surfaces.

The light shielding area surrounds the light transmitting area, and the aperture diaphragm effect can be realized. The smaller the light-transmitting area is, the larger the depth of field of the image formed after the light penetrates through the light-transmitting area is; the larger the light-transmitting area is, the smaller the depth of field of the image formed after the light penetrates through the light-transmitting area is. The depth of field is a range of distances between the front and rear of the subject measured at the front edge of the camera or other imaging device, where a sharp image can be obtained. The larger the depth of field is, the larger the range in which the subject is imaged clearly is, and the greater the probability that a clear image can be captured.

The diffractive microstructure 302 is formed on one side of the transparent substrate 113a and is used for modulating the phase of the light penetrating through the transparent region to increase the depth of field during macro photography, thereby improving the effect of macro photography. The diffractive microstructure 302 may be a phase surface. The diffractive microstructure 302 is made of glass or resin.

The phase distribution formula of the diffraction microstructure is that z is ax³+by³(ii) a Wherein x and y are coordinates of the diffractive microstructure, z is a rise from a center vertex of the diffractive microstructure in the optical axis direction at a position of the coordinates (x, y), and a and b are preset parameters. The central vertex refers to the center point where the center is symmetrical. Elevation refers to the distance from the center vertex. The values of a and b can be set according to requirements, and the values of a and b can be the same or different. a and b are positive numbers, e.g., a equals 0.03 and b equals 0.03.

The coordinates of the diffractive microstructure and the coordinates of the phase plate are identical. The mechanical centre coordinates of the diffractive microstructure may be (0, 0). The size and shape of the phase plate can be set as desired. For example, the phase plate may be circular with a diameter of 1mm, or square with a side of 1 mm.

In the phase plate 202, the phase plate 202 includes the light shielding member 304, the light shielding member 304 is disposed on the phase plate 202 to form a light shielding region, and the light shielding region surrounds the light transmitting region to form an aperture stop effect, so that the depth of field can be increased when light passes through the light transmitting region to form an image. Meanwhile, the diffraction microstructure of the phase plate can be used for carrying out phase modulation on the light, so that the depth of field during shooting can be increased, and the shooting effect is improved.

Fig. 4 is a schematic view of a cross-section of a phase plate in another embodiment. As shown in fig. 4, the phase plate 202 further includes a light-transmissive substrate 402, the diffractive microstructure 302 is disposed on one side of the light-transmissive substrate 402, and the light-shielding member 304 covers the light-transmissive substrate 402 and/or the diffractive microstructure 302 to form a light-shielding region in the phase plate 202.

The light-transmitting substrate 402 is in millimeter level, and the diffraction microstructure 302 is in micron level, so that the whole structural strength is ensured, and meanwhile, a good diffraction effect can be provided, the phase of light can be adjusted, and the shooting requirement of large depth of field can be met. For example, as shown in fig. 4, the thickness h of the transparent substrate 402 ranges from 0.15mm to 1.5mm, such as 0.15mm, 0.5mm, 1.05mm, 1.15mm, or 1.5 mm. The height d of the diffractive microstructure 302 in the thickness direction of the light transmissive substrate 402 ranges from 2 μm to 20 μm (micrometer), such as 2 μm, 5 μm, 10 μm, 15 μm, or 20 μm.

The transparent substrate 402 is made of glass or resin. The side of the light-transmitting substrate 402 facing away from the diffractive microstructure 302 is a plane or a spherical surface, and the side facing the diffractive microstructure 302 is a plane, which is not limited herein for the configuration of the light-transmitting substrate 402. In other embodiments, the side of the light-transmissive substrate 402 facing away from the diffractive microstructure 302 may also be aspheric. The shape of the surface of the phase plate 202 perpendicular to the optical axis direction may be set as needed. For example, the surface of the phase plate 202 perpendicular to the optical axis direction is circular or square.

In one embodiment, as shown in fig. 4, the light-shielding member 304 covers the light-transmissive substrate 402 and is on the same side as the diffractive microstructure 302 of the light-transmissive substrate 402.

In another embodiment, as shown in fig. 5, the light shield 304 is overlaid on the light transmissive substrate 402 and on a different side from the diffractive microstructures 302 of the light transmissive substrate 402.

In another embodiment, as shown in fig. 6, the light shield 304 covers the light transmissive substrate 402 and the diffractive microstructure 302.

In another embodiment, as shown in fig. 7, the light shield 304 overlies the light transmissive substrate 402 and is between the light transmissive substrate 402 and the diffractive microstructure 302.

In another embodiment, as shown in fig. 8, a light shield 304 overlies the diffractive microstructure 302.

In another embodiment, as shown in fig. 9, the light shielding member 304 covers both sides of the light-transmissive substrate 402 perpendicular to the optical axis direction.

In another embodiment, as shown in fig. 10, the light-shielding member 304 covers the light-transmissive substrate 402 and the diffractive microstructure 302 on one side facing the diffractive microstructure 302, and the light-shielding member 304 covers the light-transmissive substrate 402 on the other side facing away from the diffractive microstructure 302.

In another embodiment, as shown in fig. 11, the light-shielding member 304 covers the light-transmissive substrate 402 on one side facing the diffractive microstructure 302 and between the light-transmissive substrate 402 and the diffractive microstructure 302, and the light-shielding member 304 covers the light-transmissive substrate 402 on the other side facing away from the diffractive microstructure 302.

In one embodiment, the phase plate 202 further comprises an anti-reflection film covering the light-transmissive substrate 402 and/or the diffractive microstructures 302 in the light-transmissive regions and covering the light-transmissive substrate 402 in the light-blocking regions.

The antireflection film mainly functions to reduce or eliminate the reflected light of optical surfaces such as lenses, prisms, plane mirrors and the like, thereby increasing the light transmission of the elements and reducing or eliminating the stray light of the system.

In one embodiment, the antireflective coating covers the light transmissive substrate 402 in the light transmissive region and covers the light transmissive substrate 402 in the light blocking region.

In another embodiment, the antireflective coating covers the diffractive microstructures 302 in the light-transmitting regions and covers the light-transmitting substrate 402 in the light-blocking regions.

In another embodiment, the antireflective coating covers the light transmissive substrate 402 and the diffractive microstructures 302 in the light transmissive regions, and covers the light transmissive substrate 402 in the light opaque regions.

The phase plate has light-transmitting regions on both side surfaces perpendicular to the optical axis direction. The light-transmitting region on one side may be covered with the antireflection film, and the light-transmitting regions on both sides may be covered with the antireflection film.

In this embodiment, in the light-transmitting substrate 402 and/or the diffractive microstructure 302 in the light-transmitting region, when light penetrates the light-transmitting region, the antireflection film can reduce or eliminate reflected light or stray light, so that more light can be obtained, more information can be obtained in subsequent imaging, and imaging is clearer.

In one embodiment, the antireflective film comprises a plurality of silica sub-films and a plurality of titania sub-films, the silica sub-films and the titania sub-films being alternately stacked on top of each other.

Wherein, the material of the silicon dioxide sub-membrane is silicon dioxide (SIO2), and the material of the titanium dioxide sub-membrane is titanium dioxide (TIO 2). The number of layers of the silicon dioxide sub-film and the titanium dioxide sub-film can be set according to needs, and the thickness of each layer of the sub-film can also be set according to needs, and is not limited.

In one embodiment, the silicon dioxide sub-film and the titanium dioxide sub-film have 7 layers, and the 1 st layer to the 7 th layer are sequentially: a silica sub-film, a titania sub-film, and a silica sub-film.

The thickness of each layer of the silicon dioxide sub-film or the titanium dioxide sub-film can be set according to needs. For example, the thicknesses of the 1 st to 7 th layers are, in order: 176.13, 12.84, 35.07, 45.0, 14.98, 33.06, 91.88nm (nanometers), as shown in table one:

number of layers	1	2	3	4	5	6	7
								Material	SIO2	TIO2	SIO2	TIO2	SIO2	TIO2	SIO2
Thickness (nm)	176.13	12.84	35.07	45.0	14.98	33.06	91.88

In one embodiment, the light shield includes a single chromium sub-film, a multi-layer silicon dioxide sub-film, and a multi-layer chromium oxide sub-film in a stacked arrangement; the single-layer chromium sub-film is arranged on the central layer of the light shading part, the two side surfaces of the single-layer chromium sub-film respectively comprise a plurality of layers of silicon dioxide sub-films and chromium oxide sub-films which are alternately stacked, and the sub-films arranged on the two side surfaces of the single-layer chromium sub-film are arranged in a mirror image mode.

The material of the chromium sub-film is Chromium (CR), the chromium sub-film is a single-layer film, namely the number of the chromium sub-films is 1, and the chromium sub-film is arranged on the central layer of the light shielding member. The material of the silicon dioxide sub-film is silicon dioxide (SIO2), and the material of the chromium oxide sub-film is chromium oxide (CR2O 3). The number of layers of the silicon dioxide sub-film and the chromium oxide sub-film can be set according to needs, and the thickness of the chromium sub-film and each layer of the sub-film can also be set according to needs, without limitation.

In one embodiment, the single chromium sub-film, the multi-layer silicon dioxide sub-film and the multi-layer chromium oxide sub-film comprise 21 layers, and the 1 st layer to the 21 st layer are sequentially: a silicon dioxide sub-film, a chromium oxide sub-film, a chromium oxide sub-film, a silicon dioxide sub-film, a chromium oxide sub-film, and a silicon dioxide sub-film.

The thickness of the chromium sub-film can be set according to needs, and the thickness of each layer of silicon dioxide sub-film or each layer of chromium oxide sub-film can be set according to needs. For example, the thicknesses of the 1 st to 21 st layers are, in order: 34.52, 19.35, 50.47, 25.38, 19.5, 249.78, 15, 136.91, 81.3, 56.73, 120, 54.05, 79.73, 255.0, 15.83, 149.08, 15.0, 132.86, 31.1, 15.39, 22.23nm (nanometers), as shown in table two:

fig. 12 is a schematic diagram illustrating the effect of the light-shielding member in one embodiment. The light-shielding effect of the light-shielding member can be expressed by Optical Density (OD). Optical density is a measure of the property of an object to absorb light, i.e., the amount of incident light compared to the amount of reflected or transmitted light, usually expressed as the decimal logarithm of the reciprocal of the transmission or reflection. As shown in FIG. 12, the optical density of the visible light band with the wavelength of (wavelength)400-700 nm is 6-11, which reaches the extinction standard (OD5) of the conventional SOMA light-shielding sheet.

Fig. 13 is a schematic illustration of the antireflective effect of the light shield and antireflective film in one embodiment. Shown in fig. 13 is a subtraction curve for both sides of the phase plate 202. The reflectivity (reflection) of a visible light band with the wavelength of (wavelength)400-700 nanometers (nm) is within 1 percent, and the antireflection effect is effectively achieved.

The present application further provides a method for manufacturing a phase plate 202, as shown in fig. 14, including the following steps:

step 1402, covering a first region on at least one side of the light-transmitting member with photoresist, covering a second region except the first region with a light-shielding member to form a light-shielding region, and surrounding the first region with the light-shielding region; the first region and the second region are located on the same side of the light-transmitting member.

The light-transmitting member refers to a member capable of transmitting light. The light-transmitting member may be a light-transmitting plate, a light-transmitting film, or the like. The light-transmitting member may be made of glass or resin.

The first region refers to a region covering the photoresist. The second area is an area other than the first area in the same side of the first area. The second area is an area covering the light-shielding member 304, i.e., a light-shielding area.

The photoresist refers to a mixed liquid sensitive to light, which is composed of photosensitive resin, sensitizer, solvent, etc., and is used as a material for an anti-corrosion coating in a photolithography process.

The shading area surrounds the first area to form an aperture stop effect, and the depth of field of imaging can be increased after light penetrates through the light-transmitting area.

In one embodiment, one side of the light-transmitting member includes a first region, and the second region is on the same side as the first region, i.e., the side of the light-transmitting member including the first region also includes the second region. In another embodiment, both sides of the light-transmissive member include a first region, and the second region is on the same side as the first region, i.e., both sides of the light-transmissive member also include a second region.

Step 1404, removing the photoresist to obtain a light transmission region, and arranging a diffraction microstructure in the light transmission region to obtain the phase plate.

Diffraction refers to the physical phenomenon of signal waves propagating off the original straight line when encountering an obstacle. The diffractive microstructure 302 is a microstructure having a diffractive function. The pattern of diffractive microstructures 302 can be arranged as desired. The computer device acquires a preset pattern of diffractive microstructures 302, which is arranged in the light-transmitting area to form the diffractive microstructures 302. After the diffractive microstructure 302 is provided in the light-passing region, the phase plate 202 can be obtained.

The light-transmitting piece is in millimeter level, and the diffraction microstructure 302 is in micron level, so that the whole structural strength is ensured, a good diffraction effect can be provided, the phase of light can be adjusted, and the shooting requirement of large depth of field can be met. For example, the thickness h of the light-transmitting member ranges from 0.15mm to 1.5mm, such as 0.15mm, 0.5mm, 1.05mm, 1.15mm, or 1.5 mm. The height d of the diffractive microstructure 302 in the thickness direction of the light transmissive member may range from 2 μm to 20 μm, such as 2 μm, 5 μm, 10 μm, 15 μm, or 20 μm.

The light-transmitting member is made of glass or resin. The side of the light-transmitting member facing away from the diffractive microstructure 302 is a plane or a spherical surface, and the shape of the light-transmitting member is not limited herein. The phase plate 202 is circular or square in cross-section.

In this embodiment, the first region on at least one side of the light-transmitting member is covered with the photoresist, the second region except the first region is covered with the light-shielding member 304 to form a light-shielding region, and the light-shielding region surrounds the first region to form an aperture stop effect, so that the depth of field of the image can be increased after the light penetrates through the light-transmitting region. Meanwhile, the diffraction microstructure of the phase plate can be used for carrying out phase modulation on the light, so that the depth of field during shooting can be increased, and the shooting effect is improved.

In one embodiment, before the first region of at least one side of the light-transmissive member is covered with the photoresist, the method further includes: a lift-off process (lift-off) is adopted to make a photoetching pattern on the light-transmitting piece, so that the light-transmitting piece with the photoetching pattern is obtained; a first region on at least one side of the light-transmitting member having the photoresist pattern is covered with a photoresist. The photolithographic pattern can be set as required, and is not limited herein.

In one embodiment, after the diffractive microstructure 302 is disposed in the light-passing region to obtain the phase plate 202, the method further includes: an antireflection film is coated on the light-transmitting member and/or the diffractive microstructure 302 in the light-transmitting region and on the light-transmitting member in the light-shielding region.

In one embodiment, the antireflective film covers the light transmissive member in the light transmissive region and the light transmissive member in the light blocking region. In another embodiment, the antireflective coating covers the diffractive microstructures 302 in the light-transmitting regions, as well as the light-transmitting member in the light-blocking regions. In another embodiment, the antireflective film covers the light transmissive member and the diffractive microstructures 302 in the light transmissive region and the light transmissive member in the light blocking region.

In this embodiment, in the light-transmitting member and/or the diffractive microstructure 302 in the light-transmitting region, when light penetrates the light-transmitting region, the antireflection film can reduce or eliminate reflected light or stray light, so that more light can be obtained, more information can be obtained in subsequent imaging, and imaging is clearer.

The thickness of each layer of the silicon dioxide sub-film or the titanium dioxide sub-film can be set according to needs. For example, the thicknesses of the 1 st to 7 th layers are, in order: 176.13, 12.84, 35.07, 45.0, 14.98, 33.06, 91.88nm (nanometers).

The thickness of the chromium sub-film can be set according to needs, and the thickness of each layer of silicon dioxide sub-film or each layer of chromium oxide sub-film can be set according to needs. For example, the thicknesses of the 1 st to 21 st layers are, in order: 34.52, 9.35, 50.47, 25.38, 19.5, 249.78, 15, 136.91, 81.3, 56.73, 150, 54.05, 79.73, 255.0, 15.83, 149.08, 15.0, 132.86, 31.1, 15.39, 22.23nm (nanometers).

It should be understood that, although the steps in the flowchart of fig. 14 are shown in order as indicated by the arrows, the steps are not necessarily performed in order as indicated by the arrows. The steps are not performed in the exact order shown and described, and may be performed in other orders, unless explicitly stated otherwise. Moreover, at least a portion of the steps in fig. 14 may include multiple sub-steps or multiple stages that are not necessarily performed at the same time, but may be performed at different times, and the order of performance of the sub-steps or stages is not necessarily sequential, but may be performed in turn or alternately with other steps or at least a portion of the sub-steps or stages of other steps.

Referring to fig. 15, fig. 15 is a schematic structural diagram of a mobile terminal according to an embodiment of the present application. The mobile terminal 10 may include Radio Frequency (RF) circuitry 1501, memory 1502 including one or more computer-readable storage media, an input unit 1503, a display unit 1504, a sensor 1505, audio circuitry 1506, a Wireless Fidelity (WiFi) module 1507, a processor 1508 including one or more processing cores, and a power supply 1509. Those skilled in the art will appreciate that the mobile terminal 10 configuration illustrated in FIG. 15 does not constitute a limitation of the mobile terminal 10 and may include more or less components than those illustrated, or some components in combination, or a different arrangement of components.

The rf circuit 1501 may be configured to receive and transmit information, or receive and transmit signals during a call, and in particular, receive downlink information from a base station and then send the received downlink information to one or more processors 1508 for processing; in addition, data relating to uplink is transmitted to the base station. In general, radio frequency circuits 1501 include, but are not limited to, an antenna, at least one Amplifier, a tuner, one or more oscillators, a Subscriber Identity Module (SIM) card, a transceiver, a coupler, a Low Noise Amplifier (LNA), a duplexer, and the like. In addition, the radio frequency circuit 1501 can also communicate with a network and other devices by wireless communication. The wireless communication may use any communication standard or protocol, including but not limited to Global System for Mobile communications (GSM), General Packet Radio Service (GPRS), Code Division Multiple Access (CDMA), Wideband Code Division Multiple Access (WCDMA), Long Term Evolution (LTE), email, Short Message Service (SMS), and the like.

The memory 1502 may be used to store applications and data. The memory 1502 stores applications containing executable code. The application programs may constitute various functional modules. The processor 1508 executes various functional applications and data processing by executing application programs stored in the memory 1502. The memory 1502 may mainly include a storage program area and a storage data area, wherein the storage program area may store an operating system, an application program required by at least one function (such as a sound playing function, an image playing function, etc.), and the like; the storage data area may store data (such as audio data, a phonebook, etc.) created according to the use of the mobile terminal 10, and the like. Further, the memory 1502 may include high speed random access memory, and may also include non-volatile memory, such as at least one magnetic disk storage device, flash memory device, or other volatile solid state storage device. Accordingly, the memory 1502 may also include a memory controller to provide the processor 1508 and the input unit 1503 access to the memory 1502.

The input unit 1503 may be used to receive input numbers, character information, or user characteristic information (such as a fingerprint), and generate a keyboard, mouse, joystick, optical, or trackball signal input related to user setting and function control. Specifically, in one particular embodiment, the input unit 1503 may include touch sensitive surfaces as well as other input devices. The touch-sensitive surface, also referred to as a touch display screen or a touch pad, may collect touch operations by a user (e.g., operations by a user on or near the touch-sensitive surface using a finger, a stylus, or any other suitable object or attachment) thereon or nearby, and drive the corresponding connection device according to a predetermined program. Alternatively, the touch sensitive surface may comprise two parts, a touch detection means and a touch controller. The touch detection device detects the touch direction of a user, detects a signal brought by touch operation and transmits the signal to the touch controller; the touch controller receives touch information from the touch sensing device, converts it to touch point coordinates, and sends it to the processor 1508, where it can receive and execute commands from the processor 1508.

The display unit 1504 may be used to display information entered by or provided to the user as well as various graphical user interfaces of the mobile terminal 10, which may be comprised of graphics, text, icons, video, and any combination thereof. The display unit 1504 may include the liquid crystal panel described above.

Further, the touch-sensitive surface may overlie the liquid crystal panel, and when a touch operation is detected on or near the touch-sensitive surface, the touch operation is transmitted to the processor 1508 to determine the type of touch event, and the processor 1508 then provides a corresponding visual output on the liquid crystal panel according to the type of touch event.

Although in FIG. 15 the touch sensitive surface and the liquid crystal panel are implemented as two separate components for input and output functions, in some embodiments the touch sensitive surface may be integrated with the liquid crystal panel for input and output functions. It is understood that the touch display screen may include an input unit 1503 and a display unit 1504.

The mobile terminal 10 may also include at least one sensor 1505, such as light sensors, motion sensors, and other sensors. Specifically, the light sensor may include an ambient light sensor that may adjust the brightness of the liquid crystal panel according to the brightness of ambient light, and a proximity sensor that may turn off the liquid crystal panel and/or the backlight when the mobile terminal 10 is moved to the ear. As one of the motion sensors, the gravity acceleration sensor can detect the magnitude of acceleration in each direction (generally, three axes), can detect the magnitude and direction of gravity when the mobile phone is stationary, and can be used for applications of recognizing the posture of the mobile phone (such as horizontal and vertical screen switching, related games, magnetometer posture calibration), vibration recognition related functions (such as pedometer and tapping), and the like; as for other sensors such as a gyroscope, a barometer, a hygrometer, a thermometer, and an infrared sensor, which may be further configured on the mobile terminal 10, detailed descriptions thereof are omitted.

The audio circuit 1506 may provide an audio interface between a user and the mobile terminal 10 through a speaker, microphone, etc. The audio circuit 1506 may convert the received audio data into an electrical signal, transmit the electrical signal to a speaker, and convert the electrical signal into a sound signal for output; on the other hand, the microphone converts a collected sound signal into an electric signal, converts the electric signal into audio data after being received by the audio circuit 1506, and then outputs the audio data to the processor 1508 to be processed, and then passes through the radio frequency circuit 1501 to be transmitted to, for example, another mobile terminal 10, or outputs the audio data to the memory 1502 for further processing. The audio circuitry 1506 may also include an earphone jack to provide communication of a peripheral earphone with the mobile terminal 10.

Wireless fidelity (WiFi) belongs to a short-distance wireless transmission technology, and the mobile terminal 10 can help a user send and receive e-mails, browse web pages, access streaming media and the like through the wireless fidelity module 1507, and provides wireless broadband internet access for the user. Although fig. 15 shows the wireless fidelity module 1507, it is understood that it does not belong to the essential constitution of the mobile terminal 10, and may be omitted entirely as needed within the scope not changing the essence of the invention.

The processor 1508 is a control center of the mobile terminal 10, connects various parts of the entire mobile terminal 10 using various interfaces and lines, and performs various functions of the mobile terminal 10 and processes data by running or executing applications stored in the memory 1502 and calling up data stored in the memory 1502, thereby performing overall monitoring of the mobile terminal 10. Optionally, processor 1508 may include one or more processing cores; preferably, the processor 1508 may integrate an application processor, which handles primarily the operating system, user interface, applications, etc., and a modem processor, which handles primarily wireless communications. It is to be appreciated that the modem processor described above may not be integrated into processor 1508.

The mobile terminal 10 also includes a power supply 1509 that provides power to the various components. Preferably, the power supply 1509 may be logically connected to the processor 1508 via a power management system, such that the power management system may manage charging, discharging, and power consumption. The power supply 1509 may also include any components including one or more dc or ac power sources, recharging systems, power failure detection circuitry, power converters or inverters, power status indicators, and the like.

Although not shown in fig. 15, the mobile terminal 10 may further include a bluetooth module or the like, which will not be described in detail herein. In specific implementation, the above modules may be implemented as independent entities, or may be combined arbitrarily to be implemented as the same or several entities, and specific implementation of the above modules may refer to the foregoing method embodiments, which are not described herein again.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present application, and the description thereof is more specific and detailed, but not construed as limiting the claims. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the concept of the present application, which falls within the scope of protection of the present application. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims

1. The phase plate is characterized by comprising a shading piece, wherein the shading piece is arranged on the phase plate to form a shading area; the phase plate is provided with a light-transmitting area, the light-shielding area surrounds the light-transmitting area, and the light-transmitting area is provided with a diffraction microstructure which modulates the phase of light when the light penetrates through the light-transmitting area.

2. The phase plate according to claim 1, further comprising a light-transmissive substrate, wherein the diffractive microstructure is disposed on one side of the light-transmissive substrate, and wherein the light-shielding member covers the light-transmissive substrate and/or the diffractive microstructure to form the light-shielding region in the phase plate.

3. The phase plate according to claim 2, further comprising a antireflection film covering the light-transmitting substrate and/or the diffractive microstructures in the light-transmitting regions and covering the light-transmitting substrate in the light-blocking regions.

4. The phase plate of claim 3, wherein the antireflection film comprises a plurality of silica sub-films and a plurality of titania sub-films, the silica sub-films and the titania sub-films being alternately stacked on top of each other.

5. The phase plate of claim 4, wherein the silica sub-film and the titania sub-film comprise 7 layers, and the 1 st to 7 th layers are, in order: a silica sub-film, a titania sub-film, and a silica sub-film.

6. The phase plate of any of claims 1 to 5, wherein the light shield comprises a single layer of chromium sub-film, a multi-layer of silicon dioxide sub-film, and a multi-layer of chromium sesquioxide sub-film in a stacked arrangement; the single-layer chromium sub-film is arranged on the central layer of the light shading part, the two side faces of the single-layer chromium sub-film respectively comprise a plurality of layers of silicon dioxide sub-films and chromium sesquioxide sub-films which are alternately stacked, and the sub-films arranged on the two side faces of the single-layer chromium sub-film are arranged in a mirror image mode.

7. The phase plate of claim 6, wherein the single chromium sub-film, the multi-layer silica sub-film, and the multi-layer chromia sub-film comprise 21 layers, and the 1 st to 21 st layers are, in order: a silicon dioxide sub-film, a chromium oxide sub-film, a chromium oxide sub-film, a silicon dioxide sub-film, a chromium oxide sub-film, and a silicon dioxide sub-film.

8. The phase plate according to any of claims 1 to 5, wherein the thickness of the light-transmissive substrate ranges from 0.15mm to 1.5mm and the height of the diffractive microstructure in the thickness direction of the light-transmissive substrate ranges from 2 μm to 20 μm.

9. The phase plate according to any of claims 1 to 5, wherein the light-transmissive substrate is glass or resin.

10. A phase plate according to claims 1 to 5, wherein the side of the light-transmissive substrate facing away from the diffractive microstructure is planar or spherical.

11. A phase plate according to claims 1 to 5, wherein the surface of the phase plate perpendicular to the optical axis is circular or square.

12. A camera module comprising a photosensitive element, a filter and a plurality of lenses, wherein the camera module further comprises a phase plate according to any one of claims 1 to 11; the phase plate, the lenses, the optical filter and the photosensitive element are sequentially arranged along the same optical axis direction, and the phase plate, the lenses and the optical filter are all located on the photosensitive side of the photosensitive element.

13. A mobile terminal characterized by comprising the camera module of claim 12.