CN111988499A - Imaging layer, imaging device, electronic equipment, zone plate structure and photosensitive pixel - Google Patents

Abstract

The present application discloses an imaging layer, an imaging device, an electronic device, a zone plate structure and a photosensitive pixel, comprising an imaging layer and an image sensor located on the lower side of the imaging layer, and a plurality of imaging holes are arranged on the imaging layer, Each of the imaging holes is provided with a zone plate structure, the zone plate structure includes a light-shielding zone and a light-transmitting zone, and the zone plate structure makes the light reflected by the object converge on the image sensor for imaging. A zone plate structure is arranged on the imaging layer. The zone plate structure is calculated and designed according to the principle of light interference, so that the coherence enhancement of the monochromatic light passing through the light transmission band is concentrated on the image sensor, thereby making the light converging on the image sensor. All are coherently enhanced light, which greatly amplifies the light intensity. At the same time, the relative height of the secondary peak of interference/diffraction caused by the wave nature of light and the distance between it and the main peak are also reduced due to the increased light transmission area. Thereby, the optical resolution is further improved.

Description

Imaging layer, imaging device, electronic equipment, zone plate structure and photosensitive pixel

This application claims the priority of the Chinese patent application with application number 201910430939.4 filed on May 22, 2019 with the State Intellectual Property Office of China, the entire contents of which are incorporated herein by reference.

technical field

The present application relates to the technical field of image acquisition, and in particular, to an imaging device. In addition, the present application also relates to an imaging layer, an electronic device, a zone plate structure and a photosensitive pixel.

Background technique

Existing mobile terminals, such as mobile phones, hope to achieve a full-screen design, and integrate fingerprint recognition and front-facing cameras under the display without affecting the display. There are technologies that integrate fingerprint recognition under the display screen in the prior art. For example, the prior patent CN201710086890.6 proposed a Matrix Pinhole Imaging System (MAPIS), which is used to collect object surfaces at close range. Images, such as fingerprint images, face images, etc. MAPIS can be applied to various electronic devices such as mobile phones, tablet computers, smart bracelets, etc.

MAPIS generally includes a small aperture plate and an image sensor. A plurality of imaging holes are opened on the small orifice plate. The image sensor is arranged on one side of the small orifice plate and corresponds to the position of the imaging hole. In this way, according to the principle of pinhole imaging, the light on the object on the other side of the pinhole plate can pass through the imaging hole to form an inverted image of the object on the image sensor. The light passing through each imaging hole can form a corresponding image on the image sensor, and by splicing these multiple images, a relatively complete image of the target can be obtained.

The above-mentioned MAPIS can be applied to an electronic device with a display screen to collect fingerprint images, face images, and the like. A display screen of an electronic device includes light-emitting pixels arranged in an array, and a circuit for controlling the light-emitting pixels. The circuits are usually opaque, but there are gaps between the circuits that allow light above the display to pass through these gaps to the underside of the display. A small orifice plate is arranged below the display screen, and the area through which light can pass is regulated by the position, size and shape of the imaging holes on the small orifice plate. The diameter of the imaging wells on an ideal small well plate is about 10-15 μm. At this time, the intensity of the light passing through the imaging hole is suitable and the diffraction is small, so the image formed on the image sensor has high definition and good resolution, which can meet the needs of application in electronic equipment with a display screen.

However, as the resolution of the display screen becomes higher and higher, the arrangement of light-emitting pixels becomes more and more dense, and the corresponding circuits are also more and more, which leads to a significant reduction of the gap between the circuits (for example, to about 5 μm). ), it is difficult to achieve the ideal imaging aperture requirements. When the aperture of the imaging hole is greatly reduced due to the limitation of the gap, the intensity of the light passing through the imaging hole is reduced, and the diffraction is serious, which makes it difficult for the light to be received by the image sensor and is easily submerged in the thermal noise of the image sensor.

On the other hand, there is no solution in the prior art that integrates the front camera under the display screen without affecting the display. The closest solution is a lift camera, a water drop frame, a hole in the display, etc. But both of the latter have an effect on the display.

In the patent 201811271636.4 (application number, not yet published, there is a utility model applied for on the same day), a solution for an under-screen camera is proposed. However, this solution also requires a relatively large central hole and needs to be used with a lens. And because the lens needs to be placed under the display, the thickness of the lens can hinder assembly.

SUMMARY OF THE INVENTION

The present application provides an imaging layer that solves the above-mentioned technical problems, an imaging device and an electronic device using the imaging layer by making full use of the interference enhancement properties of light.

In a first aspect, the present application provides an imaging device, comprising an imaging layer and an image sensor located on a lower side of the imaging layer, the imaging layer is provided with a plurality of imaging holes, and each imaging hole is provided with a wave band The zone plate structure includes a light-shielding zone and a light-transmitting zone, and the zone plate structure makes the light reflected by the object converge on the image sensor for imaging.

With reference to the first aspect, in a first possible implementation manner of the first aspect, when the total area of the light-transmitting bands of the zone plate structure in the imaging hole is greater than the total area of the light-shielding bands, the light-shielding bands are removed. In a second aspect, the present application provides an electronic device, including the imaging device and a display screen, the display screen including a circuit layer;

When the circuit layer includes a plurality of first light-transmitting parts, the imaging layer is provided with a number of imaging holes, the imaging holes are provided with a zone plate structure, and the imaging holes correspond to the first light-transmitting parts ; The area of the first light-transmitting portion is sufficient to set at least one zone plate structure.

In a third aspect, the present application provides an electronic device, including a display screen, an imaging layer and an image sensor;

The display screen includes a circuit layer, and the circuit layer includes a plurality of second light-transmitting parts;

the imaging layer is below or above the circuit layer;

The imaging layer includes a plurality of imaging holes, the imaging holes are provided with a zone plate structure, and the imaging layer is aligned with the circuit layer, so that the light-transmitting band of the imaging layer is connected to the second transparent belt of the circuit layer. The light parts are overlapped, wherein one of the zone plate structures corresponds to a plurality of the second light-transmitting parts;

Wherein, the wave zone plate structure includes a light-shielding belt and a light-transmitting belt; when the target object touches the display screen, after being reflected by the target object, the incident light passes through the light-transmitting part and the light-transmitting belt and converges on the display screen. imaged on the image sensor.

With reference to the third aspect, in a first possible implementation manner of the first aspect, when the imaging layer is provided with at least two imaging holes, the image-side fields of view of adjacent imaging holes do not overlap.

In combination with the third aspect and the above possible implementation manners, in a second possible implementation manner of the first aspect, when at least two imaging holes are opened on the imaging layer, the object-side fields of view of adjacent imaging holes overlap. .

In combination with the third aspect and the above possible implementation manners, in a third possible implementation manner of the first aspect, the number of the imaging holes is three.

In combination with the third aspect and the above possible implementation manners, in a fourth possible implementation manner of the first aspect, the circuit layer further includes light-emitting pixels arranged in an array, so as to reduce the number of light-emitting pixels per unit area. The imaging layer corresponding to the light-emitting pixel is provided with a plurality of imaging holes, and each of the imaging holes is provided with a zone plate structure.

With reference to the third aspect and the above possible implementation manners, in a fifth possible implementation manner of the first aspect, at least one light-emitting pixel is spaced between two adjacent missing light-emitting pixels.

In combination with the third aspect and the above possible implementation manners, in a sixth possible implementation manner of the first aspect, the distance between the image sensor and the imaging layer is set such that light emitted from a point on the object surface converges on the image. point on the sensor.

In combination with the third aspect and the above possible implementation manners, in a seventh possible implementation manner of the third aspect, the imaging hole and the light-transmitting zone of the zone plate structure are also used for through holes for circuit wiring.

In combination with the third aspect and the above possible implementation manners, in an eighth possible implementation manner of the third aspect, the imaging layer is aligned with the circuit layer, so that the light-transmitting band of the imaging layer is The overlapping area of the second light-transmitting portion is the largest or the overlapping area satisfies the preset area threshold range.

In a fourth aspect, the present application provides an imaging device including the imaging layer described in the third aspect.

In a fifth aspect, the present application provides an electronic device, including a display screen, an imaging layer and an image sensor;

The display screen includes a circuit layer, and the circuit layer includes a plurality of light-transmitting parts;

the imaging layer is located below the circuit layer;

At least three image sensors are arranged under the imaging layer, and the three image sensors are respectively used for receiving red light, green light and blue light;

The portion of the imaging layer corresponding to each of the image sensors is provided with a zone plate structure, and the zone plate structure includes a light-shielding zone and a light-transmitting zone;

When the target outside the display screen emits light, the zone plate structure corresponding to each image sensor makes the light of the corresponding wavelength converge on the corresponding image sensor, and the image processing module forms a color image.

In a sixth aspect, the present application provides an imaging layer, the imaging layer includes a light-shielding portion and a light-transmitting portion arranged by circuit lines, and the light-transmitting portion condenses light reflected by a target on an image sensor for imaging.

In a seventh aspect, the present application provides an imaging layer, wherein a zone plate structure is provided on the imaging layer, and the zone plate structure includes a first zone plate and a second zone plate with the same structure, the first zone plate The zone plate and the second zone plate are arranged up and down, so that the light in the direction of the connection line between the center points of the first zone plate and the second zone plate can pass through the first zone plate and the second zone plate sliced and imaged.

In an eighth aspect, the present application provides an imaging layer, the imaging layer includes a zone plate structure, the zone plate structure includes a light-shielding zone and a light-transmitting zone, and the imaging layer is made of a conductive material.

With reference to the eighth aspect, in a first possible implementation manner of the eighth aspect, the light-shielding strips are communicated with each other through a connector, and the connector is made of a conductive material.

With reference to the eighth aspect, in a second possible implementation manner of the eighth aspect, the imaging layer is also used for power supply.

In a ninth aspect, the present application provides an inclined zone plate structure, and the inclined zone plate structure is obtained by the following method:

The positive zone plate structure is placed on the normal plane of the incident light, and the positive zone plate structure is orthogonal to the incident optical axis, wherein the incident angle of the incident light is θ;

Taking the intersection of the focal plane of the positive zone plate structure and the optical axis of the incident light as the center, a central projection is performed on the positive zone plate structure, and the projection on the plane where the diffraction screen is located is the inclined zone plate structure.

With reference to the first implementation manner of the eighth aspect, the inclination angle of the inclined zone plate structure is away from the incident direction of ambient light, and the inclination angle is that the incident angle of the incident light is θ.

In a tenth aspect, the present application provides a split-field imaging device, including at least two imaging devices, each of the imaging devices includes a zone plate structure, and an image sensor is provided under the zone plate structure, wherein each of the imaging devices includes a zone plate structure. The zone plate structure corresponds to one image sensor, or, a plurality of the zone plate structures corresponds to one image sensor; each of the zone plate structures is used for converging the light of the object-side field of view into a corresponding image respectively On the sensor, which corresponds to the tilted field of view light, a tilted zone plate structure is used in conjunction.

In an eleventh aspect, the present application provides an imaging layer including the tilted zone plate structure.

In a twelfth aspect, the present application provides a photosensitive pixel with a narrow field of view, a field diaphragm is provided on the upper surface of the photosensitive pixel, and the zone plate structure is provided above the field diaphragm; The zone plate structure includes a light-shielding zone and a light-transmitting zone, and the zone plate structure makes the light reflected by the target converge on the image sensor for imaging;

The object plane located in the set area above the photosensitive pixel, the image plane of which falls on the plane where the field diaphragm is located; the zone plate structure and the field diaphragm make the photosensitive pixel in the set The object surface of the fixed area has an object-side field of view with a limited field of view; the object point in the object-side field of view, its image point or image spot falls in the small hole of the field diaphragm; The object point outside the object-side field of view, whose image point or image spot falls outside the aperture.

With reference to the first implementation manner of the tenth aspect, a light-shielding wall is provided between adjacent photosensitive pixels, and the light-shielding wall is located on the upper side of the photosensitive pixels.

The imaging layer of the present application can be applied to electronic equipment, especially electronic equipment with a display screen, and a zone plate structure is arranged on the imaging layer. The coherent enhancement of monochromatic light is concentrated on the image sensor, and the part of the shading band is the part of the image sensor that is coherently converged on the image sensor after calculation, so that the light converging on the image sensor is all coherent enhanced light, Greatly magnifies the light intensity. At the same time, due to the increased light transmission area, the relative height of the secondary peak of interference/diffraction caused by the wave nature of light and the distance between it and the primary peak will also decrease. Thereby, the optical resolution is further improved.

Description of drawings

In order to illustrate the technical solutions of the present application more clearly, the accompanying drawings that need to be used in the embodiments will be briefly introduced below. Other drawings can also be obtained from these drawings.

Fig. 1 is the imaging optical path diagram of MAPIS in the prior art;

Fig. 2 is the top view of the orifice plate of MAPIS in the prior art;

3 is a schematic diagram of an optical path of converging light in an implementation manner of the imaging device of the present application;

4 is a top view of an imaging layer in an implementation manner of the imaging device of the present application;

5 is a top view of a circuit layer of the application;

6 is a schematic structural diagram of an implementation manner in which the imaging device of the present application is applied to an electronic device with a display screen;

7A is a top view of another circuit layer of the application;

7B is a top view of another circuit layer of the application;

8A is a top view of the imaging layer corresponding to the circuit layer of FIG. 7A in the present application;

FIG. 8B is a top view of the imaging layer corresponding to the circuit layer of FIG. 7B in the present application;

9 is a top view of the imaging layer corresponding to the circuit layer of FIG. 5 in the present application;

10A is a schematic structural diagram of another implementation manner in which the imaging device of the present application is applied to an electronic device with a display screen;

10B is a schematic structural diagram of another implementation manner in which the imaging device of the present application is applied to an electronic device with a display screen;

11 is a schematic structural diagram of another implementation manner in which the imaging device is applied to an electronic device with a display screen after the number of light-emitting pixels per unit area is reduced in the present application;

FIG. 12 is a top view of the corresponding imaging layer according to FIG. 11;

13 is a schematic structural diagram of another implementation manner in which the imaging device of the present application is applied to an electronic device with a display screen;

14A is a schematic structural diagram of another implementation manner in which the imaging device of the present application is applied to an electronic device with a display screen;

14B is a schematic structural diagram of another implementation manner in which the imaging device of the present application is applied to an electronic device with a display screen;

15 is a schematic structural diagram of the inclined zone plate structure of the present application;

FIG. 16 is another structural schematic diagram of the inclined zone plate structure of the present application;

17 is a schematic diagram of the design of the inclined zone plate structure of the present application;

18 is a schematic structural diagram of an implementation manner in which the inclined zone plate structure of the present application is applied to a fingerprint acquisition device;

19 is a schematic diagram of the optical path of the application of the inclined zone plate structure of the present application in a fingerprint collection device;

FIG. 20 is a schematic structural diagram of an implementation manner in which the zone plate structure of the present application is applied to a photosensitive pixel.

21 is a schematic diagram of an optical path of an implementation with a double-layer imaging layer of the present application;

FIG. 22 is a schematic diagram of an optical path of another implementation manner of the present application having a double-layer imaging layer.

Detailed ways

Matrix Pinhole Image Sensing (MAPIS, MAtrix Pinhole Image Sensing) device can be used in ultra-thin optical fingerprint collection, fingerprint collection on display (FOD, Fingerprinting On Display) and other occasions.

Referring to FIGS. 1 and 2 , FIG. 1 is an imaging optical path diagram of MAPIS, and FIG. 2 is a top view of a MAPIS orifice plate. MAPIS generally includes a small orifice plate 101 and an image sensor 102 . A plurality of imaging holes are opened on the small orifice plate 101 . The image sensor 102 is disposed on one side of the aperture plate 101 and corresponds to the position of the imaging hole. In this way, according to the principle of pinhole imaging, the light on the object on the other side of the pinhole plate 101 can pass through the imaging hole to form an inverted image of the object on the image sensor 102 . The light passing through each imaging hole can form a corresponding image on the image sensor 102, and by splicing the multiple images, a relatively complete image about the target can be obtained.

However, MAPIS technology has the following shortcomings. For example: 1. For a hole with a diameter of 5 microns, according to the Airy disk calculation formula, for a green light of 0.55 μm, at a distance of 400 microns, the diameter of the Airy disk=1.22*400*0.55/5=53.68 microns. It can be seen that the diffraction spot of the light passing through the 5-micron hole is enlarged by about 10 times, and the area is correspondingly enlarged by a hundred times, so that the light intensity is weakened by a hundred times, which is very unfavorable for imaging. If it is a high-resolution display, the diameter of the small hole may be further reduced, resulting in more serious diffraction and sharp attenuation of energy. Therefore, when the aperture is too large, the image is blurred, and when the aperture is small, the energy is insufficient, resulting in insufficient energy and blurred image. 2. Some occasions restrict the use of small holes of suitable size. For example, when the MAPIS technology is applied in the OLED display screen, due to the limitation of the driving circuit in the OLED display screen, the imaging holes can only be placed in the light transmission gap of the circuit net, and the shape and size of the small holes cannot be adjusted freely to make the small holes Imaging power is insufficient and performance is degraded.

On the other hand, even if a very large hole can be made, the light intensity may not be sufficient. This is because although the total amount of transmitted light increases with the increase of the aperture, the formed light spot also increases, so the light intensity per unit area does not increase.

In order to solve this problem, this application proposes an imaging device that can be applied to electronic equipment, especially electronic equipment with a display screen, which can be used to image a target touching the display screen or to image a target outside the display screen. It can make full use of the interference-enhancing properties of light. The objects that touch the display screen can be fingerprints, palm prints, etc.

The display screen includes a circuit layer 4. Usually, the circuit layer 4 is arranged in a stacked and staggered design. It is difficult to design a small enough hole, but many smaller holes can be designed, as shown in Figure 5. In Figure 5 , the white area is the light-transmitting small holes of the circuit layer 4, and the light will interfere with each other after passing through these small holes, forming complex interference fringes, which are difficult to handle. In the past scheme, the largest of these small holes could be selected, and the other small holes could be shielded. This reduces interference, but also reduces light intensity.

Carefully analyze the coherent interference between the small holes and find that, for a certain point on the image plane, generally speaking, the interference of some small holes is coherently enhanced, and the interference of another part of the small holes is coherently destructive . From the perspective of the optical path, the optical path from the light source to the small hole is not considered for the time being. The difference between the optical path from some small holes to a certain point on the image plane is an integer multiple of the wavelength. It is coherent enhancement; when the optical path difference of the light passing through another part of the small holes and the light passing through the aforementioned small holes is a half-integer multiple of the wavelength, that is, 0.5 times, 1.5 times, 2.5 times, etc., Compared with the aforementioned small holes, this part of the light whose optical path difference is a half-integer multiple of the wavelength is coherent and destructive. Therefore, a layer of imaging layer 1 can be set to block these coherently destructive holes, leaving only the coherently enhanced holes, so that at this point on the image plane, all the light rays are coherently enhanced, so that the light intensity will be greatly increased. enhanced. Thus, a zone plate structure composed of a light-shielding zone and a light-transmitting zone is formed on the imaging layer 1 . Due to the coherent superposition, the amplitude of the light waves is directly superimposed, and the intensity of the light is proportional to the square of the amplitude, so that the final intensity of the light at this point will be proportional to the square of the number of small holes remaining. For example, if 10 holes are left, the light intensity at that point will be one hundred times higher than when only one hole is left, which greatly increases the light intensity. Based on the above analysis, in the first embodiment of the present application, an electronic device is used to image a target contacting the display screen 5, such as a fingerprint collection device for fingerprint collection through the display screen 5, see FIG. The electronic device includes: a display screen 5 and an imaging device, the imaging device includes an imaging layer 1 and an image sensor 2 , and the imaging layer 1 is located above the image sensor 2 .

In this embodiment, the imaging layer 1 is a periodic imaging plate structure, and a plurality of light-shielding and light-transmitting portions are periodically provided on the imaging layer 1 . The period may coincide with the pixel period.

The display screen 5 may include a light-emitting pixel layer and a circuit layer 4 , and the imaging layer 1 is closely attached to the lower side or the upper side of the circuit layer 4 , or the imaging layer 1 is constituted by the circuit line arrangement of the circuit layer 4 itself. When the imaging device is applied to an electronic device with a display screen 5 , the circuit layer 4 in the display screen 5 can be the same as or similar to the previous arrangement, and at this time, there is still a gap in the circuit layer 4 . Light can pass through these gaps, so these gaps can also be collectively referred to as light-transmitting parts of the circuit layer 4 . Usually, the circuit layers 4 are arranged in a stacked and staggered design, so the light-transmitting part is usually irregular in shape.

The zone plate structure 3 includes light-shielding zones and light-transmitting zones arranged at intervals. The zone plate structure 3 is calculated and designed according to the principle of light interference, so that the overall effect of the light passing through the zone plate structure 3 is enhanced. For example, a zone plate structure 3 provided in an imaging hole on the imaging layer 1 includes two light-transmitting belts and a light-shielding belt. When the area of the two light-transmitting belts is greater than the area of one light-shielding belt, the Occlusion of the shading strip, because even with the shading strip removed, the overall effect through the imaging aperture is coherently enhanced.

In order to achieve the best effect, all the coherently enhanced parts obtained by calculation can be retained to form a light-transmitting band, and all the coherently canceled parts can be blocked to form a light-shielding band. The coherent enhancement of the monochromatic light passing through the light-transmitting belt is concentrated on the image sensor, and the part of the shading belt is the part of the image sensor after the calculation of the coherent and destructive coherence of the monochromatic light, so that the light converging on the image sensor is uniform. To coherently enhance the light, the light intensity is greatly amplified.

Since the technical solution of the present application utilizes the wave characteristics such as diffraction/interference of light, and the wave characteristic of light is related to the wavelength of light, the display screen 5 emits monochromatic light when fingerprint collection is performed, and the monochromatic light passes through the display screen. 5. After the finger 6 in contact is reflected and passes through the light-transmitting part of the circuit layer 4 and the light-transmitting zone of the imaging layer 1, respectively, due to the diffraction of light and the interference of light, the image is gathered on the image sensor, and the monochromatic light can be green light or red light. and any shade of blue light. When designing the zone plate structure, according to the color of the monochromatic light, the positions of the light-shielding zone and the light-transmitting zone of the corresponding zone plate structure 3 are different. It is a huge advantage to use monochromatic light for illumination, and the zone plate structure 3 only has a converging effect on a certain monochromatic light. This means that interfering light at other wavelengths cannot converge, reducing background noise. On the other hand, the OLED screen itself emits light by mixing monochromatic light, so that it is very easy to make the screen emit monochromatic light.

The display screen 5 is a display screen with a certain light transmittance, such as an OLED screen. A fingerprint collection area is provided on the display screen 5, a number of light-emitting pixels are correspondingly arranged below the fingerprint collection area, and a plurality of light-transmitting parts are arranged on the circuit layer 4 corresponding to each light-emitting pixel. , a zone plate structure 3 capable of converging the coherently enhanced light on the image sensor is arranged under the light-transmitting part corresponding to each light-emitting pixel. A zone plate structure 3 capable of converging coherently enhanced light rays on the image sensor is provided below, so that when the electronic device is used to collect fingerprints, after the finger touches the fingerprint collection area of the display screen 5, the light incident on the image sensor The light is the light of the coherent enhancement part, and the brightness of the light is greatly amplified, which makes the collected fingerprint image brighter and clearer.

In the prior art, the fingerprint collection of the display screen 5 is based on the principle of pinhole imaging. According to the characteristics of the fingerprint, that is, the fingerprint includes a ridge part and a valley part, when the finger is in contact with the display screen 5, the ridge part is in contact with the display screen. 5 is in direct contact, and there is a gap between the valley part and the display screen 5. According to the different refractive index/reflectivity of light in different media, light and dark stripes are formed on the image sensor, but because only one small hole can penetrate Light, the bright stripes and dark stripes formed on the image sensor are relatively dark as a whole. Compared with the prior art, most of the light-transmitting parts are used in this application to ensure the amount of light entering, and the The design ensures that the incoming light is generally additive related light, greatly amplifying the brightness of the light, making the collected fingerprint image brighter and clearer. At the same time, due to the increased light transmission area, the relative height of the secondary peak of interference/diffraction caused by the wave nature of light and the distance between it and the primary peak will also decrease. Thereby, the optical resolution is further improved.

In conventional optics, a Fresnel zone plate is viewed as a lens with a focal length and depth of field. For a fixed object, the image surface can only be imaged within a certain distance range; for a fixed image surface, the object can only place the image on the image surface within a certain range. In the under-screen fingerprint detection scene, the object distance is fixed, so the image distance is also fixed, and the formed image should fall on the sensor. However, due to the limitation of assembly precision, the image sensor often cannot be located on the image plane accurately, but has a certain error. At this time, a relatively large depth of field is required to allow for this error. If the zone plate structure is set to have only one ring or a smaller number of rings, there can be a larger depth of field to allow for this error. Generally, in this application, it can be considered that depth of field = focal length/number of wavebands.

The imaging layer 1 is arranged on the image sensor, and the imaging layer 1 is located above or below the circuit layer 4. The circuit layer 4 includes multiple layers of circuits for driving the light-emitting pixels. There are a plurality of light-transmitting parts on the circuit layer 4, and the light-transmitting parts may be of regular shape or irregular shape. In practical application, the plurality of light-transmitting parts may be as shown in FIG. The situation includes several relatively large light-transmitting parts. For the convenience of description, the relatively large light-transmitting part is referred to as the first light-transmitting part. Structure 3: The multiple light-transmitting parts may also be as shown in Figure 5, and the area of all the light-transmitting parts is relatively small. For the convenience of description, the relatively small light-transmitting part is called the second light-transmitting part. The second light-transmitting portion means that the light-transmitting portion is insufficient to set a plurality of wavelength bands. For the situation shown in FIG. 7A and FIG. 7B , several light-transmitting parts (first light-transmitting parts) with relatively large areas are selected, and a corresponding zone plate is set at the position of the imaging layer 1 corresponding to the selected first light-transmitting part. Structure 3. Referring to FIGS. 8A and 8B , a plurality of zone plate structures 3 are provided on the imaging layer 1 , and each zone plate structure 3 cooperates with a corresponding first light-transmitting portion respectively. It should be noted that the zone plate structure in this case is only partially exposed, and the zone plate structure 3 arranged in the first light-transmitting part refers to a structure including a light-shielding strip and a light-transmitting strip arranged at intervals, which is relatively complete. For the concentric ring structure, the zone plate structure 3 is equivalent to a part of a complete concentric ring structure (see FIGS. 8A and 8B ). The zone plate structures 3 corresponding to the first light-transmitting parts of different shapes are different. Each zone plate structure 3 is calculated and designed according to the principle of light interference, so that the coherence enhancement of the monochromatic light passing through the first light-transmitting part and the light-transmitting zone is concentrated on the image sensor, which greatly amplifies the light. powerful. For the zone plate structure 3 corresponding to the above situation, it can be understood that an imaging hole of the same shape and size is firstly set at the position of the imaging layer 1 corresponding to the selected first light-transmitting part, and then according to the monochrome incident to the imaging hole The wavelength of the light calculates the optical path of the light passing through the imaging aperture to a certain point on the image sensor 2, and calculates the coherently enhanced interference light and the coherent destructive interference light. Among them, the setting of light transmission is retained in the coherent enhancement part, and the coherent and destructive part is blocked. It forms an occlusion band, so that the light entering the image sensor has the effect of coherent addition, which greatly amplifies the light intensity. On the other hand, due to the relationship of processing accuracy, it may be difficult to realize a too small zone plate structure. Therefore, when the sum of the areas of the light-transmitting zones in the zone plate structure is greater than the sum of the areas of the shading zones, the shading zone can be Removal can also ensure that the light passing through the imaging hole is generally enhanced. Although this reduces the light intensity to a certain extent, it is easier to process, and it is also stronger than blocking the imaging hole.

其中，k指第k个半波带，λ是光波的波长，r_k是第k个半波带的半径。故而涉及成像视场角和景深的问题。也就是说，物像距的设置应该使一个物点发出的光线通过波带片结构3后要汇聚到图像传感器上。经过计算在电路层4选取3个透光部分，并且在三个透光部分设置对应的波带片结构3，通过这3个透光部分的光线必定会在图像传感器上找到一个光线加强点。这是由于3个点可以确定一个圆，从而在通过圆心的法线方向上，到这3个点的距离(光程)总是相同的，从而总是相干增强的。Further, the zone plate structure 3 has a focal length, and its focal length is

where k refers to the k-th half-band, λ is the wavelength of the light wave, and r _k is the radius of the k-th half-band. Therefore, it involves the problem of imaging field of view and depth of field. That is to say, the setting of the object-image distance should make the light emitted by an object point converge on the image sensor after passing through the zone plate structure 3 . After calculation, three light-transmitting parts are selected in the circuit layer 4, and the corresponding zone plate structures 3 are set in the three light-transmitting parts. The light passing through the three light-transmitting parts must find a light-enhancing point on the image sensor. This is due to the fact that 3 points can determine a circle, so that in the normal direction through the center of the circle, the distance (optical path) to these 3 points is always the same, so that the coherence is always enhanced.

For the situation shown in FIG. 5 , the area of the second light-transmitting parts is relatively small, and each second light-transmitting part is not enough to set a plurality of wavelength bands (spaced light-shielding bands and light-transmitting bands). Therefore, it is possible to A complete zone plate structure 3 is designed on the imaging layer 1. The complete zone plate structure 3 refers to a structure including a series of concentric rings. As shown in FIG. 9 , the complete zone plate structure 3 is aligned with the second light-transmitting portion of the circuit layer 4. The alignment criterion is to make the light-transmitting zone of the imaging layer coincide with the second light-transmitting portion of the circuit layer. , Preferably, the overlapping area of the second light-transmitting portion of the circuit layer 4 and the light-transmitting zone of the zone plate structure 3 satisfies the preset area threshold range, or has the largest overlapping area, so that the light transmittance reaches the highest.

Further, the light-emitting pixel layer includes light-emitting pixels arranged in an array. A circuit layer 4 is disposed below the light-emitting pixel layer, and the circuit layer 4 includes a multi-layer circuit including circuits for driving and controlling the light-emitting pixels. In addition, circuits for other purposes may also be included in the circuit layer 4 . Among them, the light-emitting pixels are not light-transmitting because they are coated with organic light-emitting materials, etc., and there are gaps between the light-emitting pixels. There is a light-transmitting part on the circuit layer 4 corresponding to the gap, so the light-transmitting part exists. Around the light-emitting pixel, based on this, the zone plate structure 3 in this application can be the light-transmitting part of the circuit layer 4 corresponding to the outer ring of the light-emitting pixel, which is equivalent to abandoning the middle rings and retaining the outer ring. or a few rings, where the diameter of the discarded part corresponds to the diameter of the light-emitting pixel.

For example, if one pixel period is 70 μm, and the opaque central portion is about 40 μm in diameter, then one ring or multiple rings of light transmitting regions can be provided in the 40 to 70 μm region outside the opaque portion.

On the other hand, existing zone plate designs are integer rings, but in our scheme, it is not necessary to start with integer rings. For example, if the pixel period is 70μm, the central part of the opaque part is about 40μm in diameter, but the zone plate designed according to the wavelength and focal length of the light wave, the diameter of the first circle is 30μm, the diameter of the second circle is 42μm, no Exactly 40µm. However, according to the formula calculation, it can be found that the 1.9th circle is exactly 40 μm. At this time, the light-transmitting part between the 1.9th circle and the 2.9th circle can be reserved, and the part between 0 and 1.9th circle can be blocked. This is also a complete waveband with the function of coherence enhancement. Moreover, the light-transmitting area of the wavelength band designed in this way is larger than the light-transmitting area found in the circuit.

It can be understood that the zone plate structure 3 mentioned in this application is not an existing circular Fresnel zone plate, but is designed according to the actual situation of the circuit layer 4, and is named as a zone for the convenience of description. Sheet structure 3.

It should also be noted that one of the zone plate structures 3 may correspond to one light-emitting pixel, or one of the zone plate structures 3 may correspond to a plurality of light-emitting pixels. Finally, all the points converged on the image sensor are combined into a complete image. However, it is better not to have one of the zone plate structures 3 corresponding to all the light-emitting pixels, because if one of the zone plate structures 3 corresponds to all the light-emitting pixels, then the outer edge of the zone plate structure 3, each band may be too thin , which cannot be processed.

It should also be noted that, the imaging hole and the light-transmitting zone of the zone plate structure can be used not only as a light path, but also as a through hole for circuit wiring. For example, it can be used as a through hole for connecting the upper and lower layers of the circuit or as a through hole for connecting the circuit layer and the pixel layer, which is more conducive to the design of the display screen.

On the one hand, the fingerprint collecting device utilizes a plurality of light-transmitting parts to increase the amount of light entering, and at the same time, compared with the prior art where only one light-transmitting part is selected for pinhole imaging, the use of a plurality of light-transmitting parts is equivalent to a light-transmitting area. On the other hand, the light intensity is increased through the zone plate structure 3, so that the light can be easily received by the image sensor, thereby improving the image clarity and resolution.

In the second embodiment of the present application, the electronic device for imaging the target outside the display screen provides the function of serving as a camera, especially a front camera.

Existing electronic devices, such as smart phones, tablet computers, etc., all include a front camera and a rear camera. The front camera includes a mirror aperture set on the display screen and an image sensor behind the mirror aperture, and the target passes through the lens. The resulting optical image is projected onto the image sensor surface, and the front-facing camera is primarily used for selfies and video calls. That is to say, the front camera needs to open a hole on the display screen, which is also the reason why the existing electronic equipment cannot achieve a full screen in the true sense.

The present application proposes an image acquisition device disposed under a display screen, which is applied to an electronic device with a display screen and is used to collect images of objects outside the display screen, which can solve the problem of inability to be installed in the prior art due to the setting of the front camera. The problem of realizing full screen.

First of all, it should be noted that all the colors in nature that can be perceived by the human eye can be obtained by combining the different intensities of the three color wavelengths of red, green and blue. This is the principle of three primary colors.

An image acquisition device provided under the display screen proposed in the present application, referring to FIG. 10A and FIG. 10B , includes a circuit layer 4, an imaging layer 1 and three image sensors, wherein the three image sensors are respectively used for receiving The image sensor 201 for red light, the image sensor 202 for receiving green light, and the image sensor 203 for receiving blue light are provided with three types of zone plate structures 3 on the imaging layer 1 corresponding to the three image sensors. Lights are designed for red, green and blue light. When imaging the target outside the display screen 5, the light emitted by the target passes through the light-transmitting part of the circuit layer 4 and the light-transmitting belt of the imaging layer 1, and falls on the three image sensors respectively, and finally the light on the three image sensors is transferred. The image is processed into a finished color image.

The second embodiment of the present application is designed based on the principle of the first embodiment, and the design principles of the three types of zone plate structures 3 will not be repeated.

Further, in order to improve the imaging quality, referring to FIG. 11 and FIG. 12 , in an implementation manner, low-resolution display can be realized in part of the display area of the display screen, and specifically, the number of light-emitting pixels per unit area can be reduced. ; For example, select one or several light-emitting pixels that are not very important on the display screen, for example, reduce a light-emitting pixel at the position where the power is displayed, so that a relatively complete imaging hole can be exposed at the corresponding position of the light-emitting pixel, so that it can be A relatively complete zone plate structure 3 is arranged at the position of the imaging hole. In another implementation manner, the circuit of the circuit layer 4 can be avoided to increase the area of the light-transmitting portion. Further, in order to reduce the impact on the display effect, several light-emitting pixels are removed at intervals, that is, there is at least one light-emitting pixel between two adjacent missing light-emitting pixels, and a corresponding zone plate can cover these removed pixels. The light-transmitting part left after the pixel emits light, thereby greatly increasing the light intensity.

Further, the light-emitting pixels of the same color are selected to be removed, that is, all the missing light-emitting pixels are light-emitting pixels of the same color. For example, when displaying the power, if only green and red are needed, the blue light-emitting pixels can be removed from the position where the power is displayed.

The imaging device cooperating with the above two achievable manners includes an imaging layer 1 and an image sensor 2 . Referring to FIG. 3 , the imaging layer 1 includes a plurality of imaging holes, and each of the imaging holes is provided with a zone plate structure 3 , as shown in FIG. 4 , the zone plate structure 3 includes light shielding arranged at intervals Band and transmission band, each zone plate structure 3 is calculated and designed according to the principle of light interference, so that the coherence enhancement of monochromatic light passing through the transmission band is concentrated on the image sensor, while the part of the shading band is calculated and designed. The color light coherently cancels the part converging on the image sensor, so that the light converging on the image sensor is coherently enhanced light, which greatly amplifies the light intensity. During imaging, each zone plate structure 3 will generate an image spot, and by splicing multiple image spots together, a complete target image can be obtained. The stitching process includes steps such as image inversion correction, brightness correction, and stitching.

Compared with the existing MAPIS imaging, the pinhole imaging used in the MAPIS imaging is free diffraction imaging, and in this application, the light is converging through the zone plate structure 3 for imaging. Therefore, under the same aperture, the imaging device of the present application has higher resolution and higher energy at the image point. This is because the zone plate structure 3 eliminates the mutual cancellation of light waves with opposite phases, thus greatly enhancing the energy of the convergence point. When there are 20 half-bands in the zone plate structure 3, the energy of the image point is about 400 times that of the free diffraction of the small hole. In addition, a larger aperture cannot be used for small-hole imaging, otherwise the image will be blurred; and when the imaging device of the present application is imaging, because it is similar to the converging light effect of a thin lens, a large aperture can be used, and there is no need to worry about image blurring. The aperture can further increase the light transmittance and enhance the imaging power.

The above two achievable manners can enable the imaging hole to concentrate more light energy for imaging. At the same time, when imaging a distant target, each point on the surface of the target will form multiple image points with parallax on the image sensor through the imaging hole, so that its depth information can be calculated based on multiple image points, or noise can be calculated. Filter out or resolution enhancement. For example, assuming that the period of the imaging holes is 0.5mm, that is, one imaging hole is set every 0.5mm, and an image sensor of 5mm*5mm is used, then 100 image spots can be obtained for one imaging. For distant objects above 30mm, it has images in these 100 image spots. Therefore, we can perform sufficient signal processing calculations based on these 100 image spots to remove noise, improve resolution, or calculate accurate depth information.

In this embodiment, there is no hole visible to the naked eye on the display screen, and it will not have a serious impact on the display, and a full screen can be truly realized. In addition, since there is no lens, the thickness can also be greatly reduced, making it easier to install under the display screen.

In order to further reduce the diffraction phenomenon of light, it is preferable to shorten the distance between the circuit layer 4 and the imaging layer 1 as much as possible.

In order to achieve this goal, photolithography technology can be used. Photolithography technology uses the principle of optical-chemical reaction and chemical and physical etching methods to transfer the circuit pattern to the single crystal surface or dielectric layer to form an effective pattern window or functional pattern. process technology. Specifically, under the action of light, the pattern on the mask is transferred to the substrate by means of a photoresist (also known as photoresist). The main process is: first, ultraviolet light is irradiated to the surface of the substrate with a layer of photoresist film through the mask, causing a chemical reaction of the photoresist in the exposed area; Photoresist (the former is called positive photoresist, the latter is called negative photoresist), so that the pattern on the mask is copied to the photoresist film; finally, the pattern is transferred to the substrate by etching technology.

Obviously, the use of photolithography technology inevitably requires the use of a mask. The applicant considers that if the manufacturer uses photolithography technology to produce the circuit layer 4 and the imaging layer 1 at the same time, then the imaging device according to the present application needs to be redesigned. A set of reticle, however, the reticle is very expensive. In order to solve this problem, the present application proposes to fix the imaging layer 1 on the image sensor.

As shown in FIG. 13, most of the electronic equipment used for imaging the target contacting the display screen is the same as the first embodiment, the difference is: the image sensor 2 is provided with a transparent glass layer 7, and the An imaging layer 1 is provided on the upper surface of the transparent glass layer 7 , and the zone plate structure 3 on the imaging layer 1 corresponds to the light-transmitting portion of the upper circuit layer 4 .

Similarly, most of the electronic equipment for imaging the target outside the display screen as shown in FIG. 14A and FIG. 14B is the same as the second embodiment, the difference is that each image sensor has A transparent glass layer 7 is provided, and an imaging layer 1 is provided on the upper surface of the transparent glass layer 7 . The zone plate structure 3 on the imaging layer 1 corresponds to the light-transmitting part of the upper circuit layer 4 .

The imaging layer 1 is fixed on the image sensor through the transparent glass, and the distance between the circuit network and the imaging layer 1 is adjusted by adjusting the thickness of the transparent glass. During production, the produced imaging device can be directly attached under the display screen. . Transparent glass does not affect the convergence of light on the image sensor, and at the same time greatly reduces production costs.

Also, for the outer edge of the zone plate structure, each zone may be too thin to be machined. By providing the imaging layer 1 on the upper surface of the image sensor 2 with the transparent glass layer 7, it is easier to process.

The imaging layer 1 in the above-mentioned embodiments of the present application is an imaging plate structure, which is arranged above or below the circuit layer 4 . Another achievable way of the imaging layer 1 proposed in the present application is to use the circuit layer 4 itself to design the intricate circuit lines of the circuit layer 4 into a structure including a light-transmitting part and a light-shielding part when designing the circuit, for example, in For the part that needs light transmission, set the circuit to be sparse or even transparent, and in the part that does not need light transmission, set the circuit to be dense and opaque. Among them, the light-transmitting part and the light-shielding part play the role of the zone plate structure, that is, the circuit layer itself can be regarded as the zone plate structure. The light-transmitting part is the coherent enhancement part of the light, and the light-shielding part is the coherent cancellation part of the light, so that the light passes through the light-transmitting part of the circuit layer 4 and then converges on the image sensor.

In addition, the imaging layer can be made of conductive material. The imaging layer is equivalent to a large-area conductor, which can be used for power supply. Compared with power supply through wires, its resistance is smaller and the voltage is more stable. When the imaging layer is arranged in the display screen, each component in the display screen that needs to be powered, such as light-emitting pixels, distance sensors, ambient light sensors, etc., can take power from the imaging layer.

Further, when power supply is required, the shading strips can be connected through connecting pieces to ensure the overall equal voltage, and the connecting pieces are made of conductive materials. For example, the shading strips can be connected by several connecting strips.

For the zone plate structure 3, a variety of different styles can be selected, such as a zone plate with even-numbered bands, a zone plate with an odd-numbered band, a ring-shaped zone plate, a rectangular grid zone plate, etc., or other special designs The zone plate can be adapted to the needs of different imaging conditions.

Further, the present application discloses an inclined zone plate structure, which is used for imaging of light with inclined angles, see FIG. 15 and FIG. 16 , respectively. Tilt zone plate structure. The light-shielding zone and the light-transmitting zone of the inclined zone plate structure 301 are not concentric rings, but are inclined on one side.

Referring to Fig. 17, Fig. 17 shows the process of how to obtain the inclined zone plate structure 301. First, a concentric annular zone plate is placed on the normal plane of the incident light (ie, the wave front of the incident plane wave). The structure, namely the positive zone plate structure 302, is orthogonal to the incident optical axis; then take the intersection of the focal plane of the positive zone plate structure 302 and the optical axis of the incident light, denoted as point F, which is the focal point of the positive zone plate structure 302 Finally, with the point F as the center, the center projection is performed on the positive zone plate structure 302, and the projection falling on the diffraction plane is the inclined zone plate structure 301. The inclined zone plate structure 301 has the best converging effect on the light incident obliquely.

In a specific example, referring to FIG. 18 , an image sensor 2 , a tilted zone plate structure 301 and a transparent glass plate 8 are included. As shown in FIG. 19 , in this example, the optimal imaging angle θ of the inclined zone plate structure 301 is 50°, and the refractive index of the transparent glass plate 8 is 1.5, so the light in the transparent glass plate 8 is rubbed toward the finger along the direction of 50° During surface propagation, total reflection will occur at the glass-air interface; while at the glass-skin interface, total reflection will be destroyed, and most of the light will be transmitted through the transparent glass plate 8 . In this way, the reflected light passes through the inclined zone plate structure 301, and after condensing and imaging, the valley-ridge line will have a strong contrast on the output image. On the other hand, after the external ambient light enters the glass from the air, its angle will be less than 41.8°, which cannot be well converged and imaged through the inclined zone plate structure 301 , thereby reducing ambient light noise.

Further, the inclination angle of the inclined zone plate structure 301 should be away from the incident direction of ambient light. For example, when an imaging device using a tilted zone plate structure is used in mobile devices such as mobile phones that can be moved outdoors, the tilt angle should be toward the lower end of the display screen, which is usually the direction away from sunlight.

It should be noted that the inclination angle of the inclined zone plate structure described in this application refers to the incident angle at which the inclined zone plate structure can make the incident light achieve the best convergence effect, that is, the inclination angle is related to the incident light. The incident angle of the light corresponds to.

The oblique zone plate structure 301 in this embodiment can be used in all other embodiments in this application. In particular, the application of the inclined zone plate structure 301 in fingerprint collection has the best effect, because the inclined angle of the inclined zone plate structure can receive the light of total reflection, and its intensity is about 6 times that of normal incidence.

The present application also provides a split-field imaging device, including at least two imaging devices, each imaging device includes a zone plate structure, and an image sensor is arranged below the zone plate structure, wherein each zone plate structure may correspond to one The image sensor can also have multiple zone plate structures corresponding to one image sensor; the inclined zone plate structure 301 is used in conjunction with the inclined field of view light. on the image sensor. The target object is divided into multiple sub-fields of view and imaged respectively on the corresponding imaging devices, and finally the partial images of the target object obtained on each imaging device are stitched into a complete target object image through image processing.

The present application further provides a device for the above-mentioned field-of-view imaging device, comprising a display screen and the above-mentioned field-of-view imaging device, where the sub-field-of-view imaging device is correspondingly disposed on a light-transmitting portion below the display screen.

The smallest unit used to receive light signals in the image collector is a photosensitive pixel (also known as a photosensitive pixel, pixel, pixel), and a number of photosensitive pixels are usually set in the image collector. The photosensitive pixels used by image collectors on the market all have a wide field of view. The field of view of the photosensitive pixel refers to the maximum angle formed by the incident light in different directions that the photosensitive pixel can respond to. When the existing image acquisition device is used for direct imaging, the field of view is large, and the resulting image is often unclear. To this end, the present application further provides a narrow-field photosensitive pixel.

As shown in FIG. 20, a narrow field of view photosensitive pixel includes a photoelectric conversion unit, a photosensitive pixel 9, and a field diaphragm 10 is set on the photosensitive pixel 9, and the field diaphragm 10 has a middle The aperture of the aperture, the aperture part can transmit light, and the part outside the aperture cannot transmit light, or a light-shielding wall 11 is set between the two photosensitive pixels 9, or a field diaphragm 10 and a light-shielding wall 11 are set at the same time. . A zone plate structure 3 is arranged above the photosensitive pixel 9, so that at the object point A within the set field of view, the light emitted by it will pass through the zone plate structure 3 and converge on the field diaphragm 10 of the photosensitive pixel 9 Correspondingly, the photoelectric conversion unit can receive high-intensity light, so that the image in the object-side field of view can be imaged clearly and produce effective output; at the object point B outside the set field of view, he emits The light will pass through the zone plate structure 3 and converge beyond the small hole of the field diaphragm 10 of the photosensitive pixel, so that the photoelectric conversion unit cannot perceive or can only perceive the light emitted by the object point outside the field of view of the object side with low intensity. light, the image outside the object-side field of view cannot be acquired or the acquired part will not affect the imaging of the light in the object-side field of view on the photoelectric conversion unit, and cannot produce effective output. In this way, the viewing angle of the photosensitive pixel can be limited. In addition, the setting of the light-shielding wall 11 can prevent the crosstalk of light with a large angle.

In the above-mentioned embodiments, a single-layer zone plate structure is adopted. Generally, a zone plate structure does not only have a convergence effect on light in one direction, but also has a convergence effect on light in a range, which is sometimes harmful. The present application provides another embodiment based on the above embodiment. Most of this embodiment is the same as the above embodiment, except that a double-layer zone plate structure is adopted, that is, the first zone plate and the second zone plate have the same structure. In other words, on the basis of the single-layer zone plate structure in the above-mentioned embodiment, an identical layer of zone plate structure is added. Below, the light transmission bands of the two-layer zone plate structure can be completely aligned or have a certain offset, and two upper and lower zone plate structures are arranged, as shown in FIG. 21 and FIG. 22 . The light in the direction of the line between the center points of the two zone plate structures can penetrate the two zone plates and image them, but not in other directions. In some cases, the light intensity of the object to be measured is particularly strong only in a certain direction, such as the case of total internal reflection in the light guide plate. By setting up the double-layer zone plate structure, only receiving light in a certain direction, for example, only receiving the reflected light generated by total reflection, can greatly increase the light intensity and improve the contrast ratio. On the other hand, when the field of view is small, the dual-layer zone plate structure can act as a collimator.

In the description of this application, it is to be understood that the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inside", " The orientation or positional relationship indicated by "outside" is based on the orientation or positional relationship shown in the accompanying drawings, which is only for the convenience of simplifying the description, rather than indicating or implying that the referred device or element must have a specific orientation or be constructed in a specific orientation. and operation, and therefore should not be construed as a limitation on this application. In addition, in the description of the present application, "plurality" means two or more.

It is sufficient to refer to each other for the same and similar parts among the various embodiments in this specification. The embodiments of the present invention described above do not limit the protection scope of the present invention.

Claims (25)

1. The imaging device is characterized by comprising an imaging layer and an image sensor positioned on the lower side of the imaging layer, wherein a plurality of imaging holes are formed in the imaging layer, a zone plate structure is arranged in each imaging hole and comprises a shading band and a light transmission band, and the zone plate structure enables light reflected by a target object to be converged on the image sensor for imaging.

2. The imaging device of claim 1, wherein the obscuration band is removed when the sum of the areas of the transparent bands of the zone plate structure within the imaging aperture is greater than the sum of the areas of the obscuration band.

3. An electronic device comprising the imaging apparatus according to claim 1 or 2 and a display screen, the display screen including a circuit layer;

when the circuit layer comprises a plurality of first light-transmitting parts, a plurality of imaging holes are formed in the imaging layer, a zone plate structure is arranged in each imaging hole, and each imaging hole corresponds to the corresponding first light-transmitting part; the area of the first light transmitting portion is sufficient to provide at least one zone plate structure.

4. An electronic device comprising a display screen, an imaging layer, and an image sensor;

the display screen comprises a circuit layer, wherein the circuit layer comprises a plurality of second light-transmitting parts;

the imaging layer is positioned below or above the circuit layer;

the imaging layer comprises a plurality of imaging holes, zone plate structures are arranged in the imaging holes, the imaging layer is aligned with the circuit layer, a light transmission belt of the imaging layer is enabled to be superposed with second light transmission parts of the circuit layer, and one zone plate structure corresponds to a plurality of second light transmission parts;

Wherein the zone plate structure comprises a shading band and a transmitting band; when the target object contacts the display screen, after the target object reflects, the incident light rays pass through the light-transmitting part and the light-transmitting belt and are converged on the image sensor to form an image.

5. The electronic device of claim 4, wherein when at least two imaging holes are formed in the imaging layer, image-side fields of view of adjacent imaging holes do not coincide.

6. The electronic device of claim 4, wherein when at least two imaging holes are formed in the imaging layer, object fields of view of adjacent imaging holes coincide.

7. The electronic device of claim 4, wherein the number of imaging apertures is 3.

8. The electronic device of claim 4, wherein the circuit layer further comprises light-emitting pixels arranged in an array, the number of light-emitting pixels per unit area is reduced, a plurality of imaging holes are formed in the imaging layer corresponding to the missing light-emitting pixels, and a zone plate structure is arranged in each imaging hole.

9. The electronic device of claim 8, wherein at least one light-emitting pixel is spaced between two adjacent missing light-emitting pixels.

10. The electronic device of claim 4, wherein the distance between the image sensor and the imaging layer is set such that light from a point on the object plane converges at a point on the image sensor.

11. The electronic device of claim 4, wherein the imaging aperture and the light-transmissive ribbon of the zone plate structure are also used for vias for circuit line routing.

12. The electronic device of claim 4, wherein the imaging layer is aligned with the circuit layer such that an area of overlap of the light-transmissive strip of the imaging layer with the second light-transmissive portion of the circuit layer is maximized or meets a predetermined area threshold range.

13. An imaging device comprising an imaging layer, the imaging layer being located below or above a circuit layer;

the circuit layer comprises a plurality of second light-transmitting parts, the imaging layer comprises a plurality of imaging holes, zone plate structures are arranged in the imaging holes, the imaging layer is aligned with the circuit layer, so that light-transmitting belts of the imaging layer are overlapped with the second light-transmitting parts of the circuit layer, and one zone plate structure corresponds to a plurality of second light-transmitting parts;

Wherein the zone plate structure comprises a shading band and a transmitting band; when the target object contacts the display screen, after the target object reflects, the incident light rays pass through the second light transmission part and the light transmission belt and are converged on the image sensor to form an image.

14. An electronic device comprising a display screen, an imaging layer, and an image sensor;

the display screen comprises a circuit layer, wherein the circuit layer comprises a plurality of light-transmitting parts;

the imaging layer is positioned below the circuit layer;

at least three image sensors are arranged below the imaging layer and are respectively used for receiving red light, green light and blue light;

the imaging layer is provided with a zone plate structure corresponding to each image sensor, and the zone plate structure comprises a shading zone and a light-transmitting zone;

when the target object outside the display screen emits light, the zone plate structure corresponding to each image sensor enables the light with the corresponding wavelength to be converged on the corresponding image sensor, and a color image is formed through the image processing module.

15. The imaging layer is characterized by comprising a light shielding part and a light transmitting part which are distributed by circuit lines, wherein the light transmitting part enables light reflected by a target object to be converged on an image sensor for imaging.

16. The imaging layer is characterized in that a zone plate structure is arranged on the imaging layer and comprises a first zone plate and a second zone plate which are identical in structure, the first zone plate and the second zone plate are arranged up and down, and light rays in a connecting line direction between central points of the first zone plate and the second zone plate can pass through the first zone plate and the second zone plate and form images.

17. An imaging layer comprising a zone plate structure including an opaque zone and a transparent zone, the imaging layer being made of a conductive material.

18. The imaging layer of claim 17, wherein the light-shielding strips are connected by a connecting member, and the connecting member is made of a conductive material.

19. The imaging layer of claim 17, wherein the imaging layer is further configured to supply power.

20. A tilted zone plate structure, wherein the tilted zone plate structure is obtained by:

placing a positive wave band plate structure on a normal plane of incident light, wherein the positive wave band plate structure is orthogonal to an incident optical axis, and the incident angle of the incident light is theta;

And taking the intersection point of the focal plane of the positive wave band plate structure and the optical axis of the incident light as a center, and carrying out central projection on the positive wave band plate structure, wherein the projection falling on the plane of the diffraction screen is an inclined wave band plate structure.

21. A tilted zone plate structure according to claim 20, wherein the tilted zone plate structure has an inclined angle away from the incident direction of ambient light, said inclined angle being the angle of incidence θ of the incident light rays.

22. A split-field imaging device is characterized by comprising at least two imaging devices, wherein each imaging device comprises a zone plate structure, an image sensor is arranged below the zone plate structure, each zone plate structure corresponds to one image sensor, or a plurality of zone plate structures correspond to one image sensor; each zone plate structure for converging object field rays onto a corresponding image sensor, wherein corresponding tilted field rays cooperate to use the tilted zone plate structure of claim 20.

23. An imaging layer comprising the tilted zone plate structure of claim 20 or 21.

24. The narrow-field photosensitive pixel is characterized in that a field diaphragm is arranged on the upper surface of the photosensitive pixel, a zone plate structure is arranged above the field diaphragm and comprises a shading band and a light transmission band, and the zone plate structure enables light reflected by a target object to be converged on the image sensor for imaging;

the object surface is positioned in a set area above the photosensitive pixel, and the image surface of the object surface is positioned on the plane of the field diaphragm; the zone plate structure and the field diaphragm enable the photosensitive pixel to have an object space field with a limited field angle on the object plane of the set area; the image point or the image spot of the object point in the object space field falls in the small hole of the field diaphragm; and the image point or the image spot of the object point positioned outside the object space field of view falls outside the small hole.

25. The narrow-field photosensitive pixel of claim 24, wherein a light-shielding wall is disposed between adjacent photosensitive pixels, the light-shielding wall being located on an upper side of the photosensitive pixel.

Images