Image sensor and intelligent terminal

Abstract

The utility model provides an image sensor and an intelligent terminal, the image sensor comprises a semiconductor substrate and a lens array, and pixel photosensitive units are arranged on the semiconductor substrate in an array; the lens array is arranged in the light incidence direction of a light sensing array formed by the pixel light sensing units, a micro lens of the lens array comprises a light gathering part used for gathering light rays and a light intensifying part used for reflecting and refracting the light rays, and the light rays enter the pixel light sensing units through the light gathering part and the light intensifying part. According to the image sensor, the shooting effect of the pixel photosensitive unit in a dark-state weak light environment can be improved, and the image quality is improved.

Description

Technical Field

[0001] This application relates to the technical field of display devices, and particularly to an image sensor and an intelligent terminal. Background Art

[0002] An image sensor refers to a device that converts optical signals into electrical signals. Generally, large-scale commercially available image sensor chips include two categories: charge-coupled device (CCD) and complementary metal oxide semiconductor (CMOS) image sensor chips. Compared with traditional CCD sensors, CMOS image sensors have the characteristics of low power consumption, low cost, and compatibility with CMOS processes, and thus are increasingly widely used. The core devices of some CMOS image sensors include photosensitive devices and lenses disposed above the light-incident side of the photosensitive devices.

[0003] In the process of conceiving and implementing this application, the inventors found that there are at least the following problems: Since the lens disposed on the light-incident side of the photosensitive device is a conventional convex lens, although it has a certain light-gathering effect, the image sensor has a poor shooting effect in a dark or weak light environment and cannot effectively solve the current customer complaint problem of poor dark shooting effect.

[0004] The foregoing description is provided to give general background information and does not necessarily constitute prior art. Summary of the Utility Model

[0005] The purpose of this application is to provide an image sensor that can improve the shooting effect of pixel photosensitive units in a dark and weak light environment and enhance the image quality.

[0006] To solve the above technical problems, this application provides an image sensor, including a semiconductor substrate and a lens array. Pixel photosensitive units are arranged in an array on the semiconductor substrate; the lens array is disposed in the light-incident direction of the photosensitive array formed by the pixel photosensitive units. The microlenses of the lens array include a light-gathering portion for converging light and a light-enhancing portion for reflecting and refracting light. Light is incident on the pixel photosensitive units after passing through the light-gathering portion and the light-enhancing portion.

[0007] Optionally, the light-incident surface of the light-gathering portion is a spherical surface convex in a direction away from the light-enhancing portion.

[0008] Optionally, the light-emitting surface of the light-gathering portion is in contact with the light-incident surface of the light-enhancing portion.

[0009] Optionally, the light-emitting surface of the light-enhancing portion is convex in a direction away from the light-gathering portion.

[0010] Optionally, the edge of the light-incident surface of the light-enhancing portion is the light-incident end, the edge of the light-emitting surface of the light-enhancing portion is the light-emitting end, and the outer diameter of the light-enhancing portion gradually decreases from the light-incident end towards the light-emitting end.

[0011] Optionally, the light-emitting surface of the light condensing part is a first plane.

[0012] Optionally, the light-incident surface of the light enhancement part is a second plane parallel to the first plane.

[0013] Optionally, the areas / shapes of the first plane and the second plane are the same.

[0014] Optionally, the central area of the light-emitting surface of the light enhancement part is a third plane parallel to the first plane.

[0015] Optionally, the image sensor further includes a light filtering unit disposed between the semiconductor substrate and the lens array, and each light filtering unit is disposed corresponding to a single pixel photosensitive unit.

[0016] Optionally, a plurality of first center lines vertically pass through the optical centers of the respective microlenses, a plurality of second center lines vertically pass through the optical centers of the respective light filtering units, and the distance between the first center line and the second center line of each pixel gradually increases from the edge of the semiconductor substrate towards the direction close to its optical center.

[0017] Optionally, the light condensing part and the light enhancement part are integrally formed.

[0018] Optionally, the pixel photosensitive unit includes a photosensitive part, a transfer transistor, a floating diffusion region, a reset transistor, and a source follower transistor. The photosensitive part is configured to convert an optical signal containing image information into an electrical signal during an exposure process; the transfer transistor is connected to the photosensitive part and the floating diffusion region and is configured to transfer the electrical signal of the photosensitive part to the floating diffusion region; the source follower transistor is configured to output the electrical signal of the floating diffusion region; and the reset transistor is configured to reset the floating diffusion region.

[0019] Optionally, the pixel photosensitive unit further includes a selection transistor, and the selection transistor is configured to selectively output the electrical signal output by the source follower transistor to a column line.

[0020] Optionally, the pixel photosensitive unit further includes a dual conversion gain transistor, and the dual conversion gain transistor is connected between the reset transistor and the floating diffusion region, and the dual conversion gain transistor is configured to increase the full well capacity of the photosensitive part during exposure.

[0021] This application also relates to an intelligent terminal, including the image sensor according to any one of the above.

[0022] The microlens of the image sensor of the present application uses a light condensing part to condense light and a light intensifying part to reflect and refract light multiple times, which can multiply the light efficiency, improve the shooting effect of pixel photosensitive units in a dark and low-light environment, reduce image noise, and thus improve the image quality. Since the outer wall of the light intensifying part of the present application satisfies the total internal reflection design of light, the light directly enters the pixel photosensitive unit after passing through the light condensing part and the light intensifying part, and there is no extra light irradiating on the adjacent pixel photosensitive units, avoiding the problem of light crosstalk.

[0023] The above description is only an overview of the technical solution of the present application. In order to be able to understand the technical means of the present application more clearly, it can be implemented according to the content of the specification. And in order to make the above and other purposes, features and advantages of the present application more obvious and understandable, the following specifically gives preferred embodiments and, in conjunction with the drawings, is described in detail as follows. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The drawings herein are incorporated into the specification and form a part of this specification, showing embodiments consistent with the present application, and are used together with the specification to explain the principles of the present application. In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, for those of ordinary skill in the art, other drawings can also be obtained according to these drawings without creative efforts.

[0025] Figure 1 Schematic diagram of the hardware structure of a mobile terminal for implementing various embodiments of the present application;

[0026] Figure 2 Schematic diagram of a communication network system architecture provided by an embodiment of the present application;

[0027] Figure 3 Partial structural schematic diagram of the image sensor of the present application;

[0028] Figure 4 Schematic diagram of the structure in which the microlens of the present application approaches the optical center of the semiconductor substrate;

[0029] Figure 5 Schematic diagram of the pixel circuit structure of the image sensor according to an embodiment of the present application;

[0030] Figure 6 Schematic diagram of the pixel circuit structure of the image sensor according to another embodiment of the present application.

[0031] The realization of the purpose of this application, its functional features and advantages will be further described with reference to the embodiments and the accompanying drawings. Through the above-mentioned drawings, specific embodiments of this application have been shown, and there will be more detailed descriptions hereinafter. These drawings and written descriptions are not intended to limit the scope of the concept of this application in any way, but to illustrate the concept of this application to those skilled in the art by referring to specific embodiments. Detailed Description of the Embodiments

[0032] Here, the exemplary embodiments will be described in detail, and the examples are shown in the drawings. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. On the contrary, they are merely examples of devices and methods consistent with some aspects of this application as detailed in the appended claims.

[0033] It should be noted that in this text, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not expressly listed, or further includes elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "including one..." does not exclude the existence of another identical element in the process, method, article or device including that element. Optionally, components, features, and elements with the same name in different embodiments of this application may have the same meaning or different meanings, and their specific meanings need to be determined based on their interpretations in the specific embodiments or further in combination with the context of the specific embodiments.

[0034] It should be understood that although the terms first, second, third, etc. may be used herein to describe various information, such information should not be limited to these terms. These terms are only used to distinguish information of the same type from each other. For example, without departing from the scope of this document, the first information may also be referred to as the second information, and similarly, the second information may also be referred to as the first information. Depending on the context, the word "if" as used herein may be interpreted as "when" or "while" or "in response to determining". Furthermore, as used herein, the singular forms "a", "an", and "the" are also intended to include the plural forms unless the context indicates otherwise. It should be further understood that the terms "comprising", "including" indicate the presence of the stated features, steps, operations, elements, components, items, kinds, and / or groups, but do not exclude the presence, occurrence, or addition of one or more other features, steps, operations, elements, components, items, kinds, and / or groups. The terms "or", "and / or", "including at least one of the following", etc. used in this application may be interpreted inclusively, or mean any one or any combination. For example, "including at least one of the following: A, B, C" means "any one of the following: A; B; C; A and B; A and C; B and C; A and B and C", and again, "A, B, or C" or "A, B, and / or C" means "any one of the following: A; B; C; A and B; A and C; B and C; A and B and C". An exception to this definition only occurs when the combination of elements, functions, steps, or operations is inherently mutually exclusive in some way.

[0035] It should be understood that although the steps in the flowcharts in the embodiments of this application are shown sequentially according to the indication of the arrows, these steps are not necessarily executed sequentially in the order indicated by the arrows. Unless there is a clear indication in this document, the execution of these steps has no strict order restriction, and they can be executed in other orders. Moreover, at least a part of the steps in the figure may include multiple sub-steps or multiple stages, and these sub-steps or stages are not necessarily executed at the same time, but can be executed at different times, and their execution order is not necessarily sequential, but can be executed alternately or in turn with at least a part of other steps or sub-steps or stages of other steps.

[0036] Depending on the context, the words "if", "when" as used herein may be interpreted as "when" or "while" or "in response to determining" or "in response to detecting". Similarly, depending on the context, the phrase "if determined" or "if detecting (stated condition or event)" may be interpreted as "when determined" or "in response to determining" or "when detecting (stated condition or event)" or "in response to detecting (stated condition or event)".

[0037] It should be understood that the specific embodiments described herein are merely for explaining the present application and are not used to limit the present application.

[0038] In the following description, suffixes such as "module", "component", or "unit" used to represent elements are only for the convenience of explaining the present application and have no specific meaning in themselves. Therefore, "module", "component", or "unit" can be used interchangeably.

[0039] The intelligent terminal can be implemented in various forms. For example, the intelligent terminal described in the present application can include intelligent terminals such as mobile phones, tablet computers, laptop computers, palmtop computers, personal digital assistants (PDAs), portable media players (PMPs), navigation devices, wearable devices, smart bracelets, pedometers, etc., as well as fixed terminals such as digital TVs and desktop computers.

[0040] In the following description, the intelligent terminal will be used as an example for illustration. Those skilled in the art will understand that, except for components specifically for mobile purposes, the structure according to the embodiments of the present application can also be applied to fixed-type terminals.

[0041] Figure 1 For a schematic diagram of the hardware structure of a mobile terminal for implementing various embodiments of the present application, please refer to Figure 1 , which is a schematic diagram of the hardware structure of an intelligent terminal for implementing various embodiments of the present application. The intelligent terminal 100 may include components such as an RF (Radio Frequency) unit 101, a WiFi module 102, an audio output unit 103, an A / V (audio / video) input unit 104, a sensor 105, a display unit 106, a user input unit 107, an interface unit 108, a memory 109, a processor 110, and a power supply 111. Those skilled in the art can understand that Figure 1 the structure of the intelligent terminal shown in does not constitute a limitation on the intelligent terminal. The intelligent terminal may include more or fewer components than shown in the figure, or combine certain components, or have different component arrangements.

[0042] Next, in combination with Figure 1 each component of the intelligent terminal will be specifically introduced:

[0043] The radio frequency unit 101 can be used for receiving and sending signals during information reception and transmission or calls. Specifically, after receiving the downlink information of the base station, it is processed by the processor 110. Additionally, the uplink data is sent to the base station. Generally, the radio frequency unit 101 includes but is not limited to an antenna, at least one amplifier, a transceiver, a coupler, a low-noise amplifier, a duplexer, etc. In addition, the radio frequency unit 101 can also communicate with the network and other devices through wireless communication. The above wireless communication can use any communication standard or protocol, including but not limited to GSM (Global System of Mobile communication), GPRS (General Packet Radio Service), CDMA2000 (Code Division Multiple Access 2000), WCDMA (Wideband Code Division Multiple Access), TD-SCDMA (Time Division-Synchronous Code Division Multiple Access), FDD-LTE (Frequency Division Duplexing-Long Term Evolution), TDD-LTE (Time Division Duplexing-Long Term Evolution), and 5G, etc.

[0044] WiFi belongs to short-distance wireless transmission technology. Through the WiFi module 102, the smart terminal can help users send and receive emails, browse the web, and access streaming media, etc. It provides users with wireless broadband Internet access. Although Figure 1 the WiFi module 102 is shown, it can be understood that it does not belong to an essential component of the smart terminal and can be completely omitted within the scope of not changing the essence of the invention according to needs.

[0045] The audio output unit 103 can convert the audio data received by the radio frequency unit 101 or the WiFi module 102 or stored in the memory 109 into an audio signal and output it as sound when the smart terminal 100 is in modes such as a call signal reception mode, a call mode, a recording mode, a voice recognition mode, a broadcast reception mode, etc. Moreover, the audio output unit 103 can also provide an audio output related to a specific function executed by the smart terminal 100 (for example, a call signal reception sound, a message reception sound, etc.). The audio output unit 103 can include a speaker, a buzzer, etc.

[0046] The A / V input unit 104 is used to receive an audio or video signal. The A / V input unit 104 can include a Graphics Processing Unit (GPU) 1041 and a microphone 1042. The graphics processor 1041 processes the image data of a still picture or a video obtained by an image capturing device (such as a camera) in a video capture mode or an image capture mode. The processed image frame can be displayed on the display unit 106. The processed image frame can be stored in the memory 109 (or other storage media) or transmitted via the radio frequency unit 101 or the WiFi module 102. The microphone 1042 can receive sound (audio data) via the microphone 1042 in operating modes such as a phone call mode, a recording mode, a voice recognition mode, etc., and can process such sound into audio data. The processed audio (voice) data can be output in a format that can be transmitted to a mobile communication base station via the radio frequency unit 101 in the case of a phone call mode. The microphone 1042 can implement various types of noise cancellation (or suppression) algorithms to cancel (or suppress) the noise or interference generated during the reception and transmission of the audio signal.

[0047] The smart terminal 100 further includes at least one sensor 105, such as a light sensor, a motion sensor, and other sensors. Optionally, the light sensor includes an ambient light sensor and a proximity sensor. Optionally, the ambient light sensor can adjust the brightness of the panel 1061 according to the brightness of the ambient light, and the proximity sensor can turn off the panel 1061 and / or the backlight when the smart terminal 100 is moved to the ear. As a type of motion sensor, the accelerometer sensor can detect the magnitude of acceleration in all directions (generally three axes), and can detect the magnitude and direction of gravity when stationary, and can be used for applications that identify the posture of the mobile phone (such as horizontal and vertical screen switching, related games, magnetometer posture calibration), vibration recognition related functions (such as a pedometer, a knock), etc.; as for other sensors that the mobile phone can also be configured with, such as a fingerprint sensor, a pressure sensor, an iris sensor, a molecular sensor, a gyroscope, a barometer, a hygrometer, a thermometer, an infrared sensor, etc., they will not be elaborated here.

[0048] The display unit 106 is used to display information input by the user or information provided to the user. The display unit 106 may include a display panel 1061, and the display panel 1061 may be configured in the form of a liquid crystal display (LCD), an organic light-emitting diode (OLED), or the like.

[0049] The user input unit 107 can be used to receive input digital or character information, and generate key signal inputs related to user settings and function controls of the smart terminal. Optionally, the user input unit 107 may include a touch panel 1071 and other input devices 1072. The touch panel 1071, also known as a touch screen, can collect touch operations of the user on or near it (such as operations of the user using a finger, a stylus, or any suitable object or accessory on or near the touch panel 1071), and drive corresponding connection devices according to a preset program. The touch panel 1071 can include two parts: a touch detection device and a touch controller. Optionally, the touch detection device detects the touch position of the user and detects the signal brought by the touch operation, and transmits the signal to the touch controller; the touch controller receives the touch information from the touch detection device, converts it into touch point coordinates, and then sends it to the processor 110, and can receive and execute commands sent by the processor 110. In addition, the touch panel 1071 can be implemented in multiple types such as resistive, capacitive, infrared, and surface acoustic wave. In addition to the touch panel 1071, the user input unit 107 may further include other input devices 1072. Optionally, the other input devices 1072 may include, but are not limited to, one or more of a physical keyboard, function keys (such as volume control keys, switch keys, etc.), a trackball, a mouse, a joystick, etc., and specific details are not limited here.

[0050] Optionally, the touch panel 1071 may cover the display panel 1061. After the touch panel 1071 detects a touch operation on or near it, it transmits it to the processor 110 to determine the type of touch event. Subsequently, the processor 110 provides a corresponding visual output on the panel 1061 according to the type of touch event. Although in Figure 1 the touch panel 1071 and the display panel 1061 are implemented as two independent components to realize the input and output functions of the smart terminal, in some embodiments, the touch panel 1071 and the display panel 1061 can be integrated to realize the input and output functions of the smart terminal, and specific details are not limited here.

[0051] The interface unit 108 serves as an interface through which at least one external device can be connected to the smart terminal 100. For example, the external device may include a wired or wireless headset port, an external power supply (or battery charger) port, a wired or wireless data port, a memory card port, a port for connecting a device with an identification module, an audio input / output (I / O) port, a video I / O port, a headphone port, and so on. The interface unit 108 can be used to receive inputs from the external device (such as data information, power, etc.) and transfer the received inputs to one or more components within the smart terminal 100 or can be used to transfer data between the smart terminal 100 and the external device.

[0052] The memory 109 can be used to store software programs and various data. The memory 109 mainly includes a program storage area and a data storage area. Optionally, the program storage area can store an operating system, application programs required for at least one function (such as a sound playback function, an image playback function, etc.); the data storage area can store data created according to the use of the mobile phone (such as audio data, phone book, etc.). In addition, the memory 109 can include high-speed random access memory and can also include non-volatile memory, such as at least one magnetic disk storage device, a flash memory device, or other non-volatile solid-state storage devices.

[0053] The processor 110 is the control center of the smart terminal, connecting various parts of the entire smart terminal using various interfaces and lines. By running or executing software programs and / or modules stored in the memory 109, and by invoking the data stored in the memory 109, the processor 110 performs various functions of the smart terminal and processes data, thereby monitoring the smart terminal as a whole. The processor 110 can include one or more processing units; preferably, the processor 110 can integrate an application processor and a modem processor. Optionally, the application processor mainly processes the operating system, user interface, and application programs, etc., and the modem processor mainly processes wireless communication. It can be understood that the above-mentioned modem processor may not be integrated into the processor 110.

[0054] The smart terminal 100 can also include a power supply 111 (such as a battery) for powering each component. Preferably, the power supply 111 can be logically connected to the processor 110 through a power management system, thereby implementing functions such as management of charging, discharging, and power consumption management through the power management system.

[0055] Although Figure 1 not shown, the smart terminal 100 can also include a Bluetooth module, etc., which will not be elaborated here.

[0056] To facilitate understanding of the embodiments of the present application, the communication network system on which the smart terminal of the present application is based will be described below.

[0057] Please refer toFigure 2 , Figure 2 This is an architecture diagram of a communication network system provided by an embodiment of the present application. The communication network system is an LTE system of the Universal Mobile Telecommunications Technology. The LTE system includes a UE (User Equipment) 201, an E-UTRAN (Evolved UMTS Terrestrial Radio Access Network) 202, an EPC (Evolved Packet Core) 203, and the IP service 204 of the operator, which are communicatively connected in sequence.

[0058] Optionally, the UE 201 may be the above-mentioned terminal 100, which will not be elaborated here.

[0059] The E-UTRAN 202 includes an eNodeB 2021 and other eNodeBs 2022, etc. Optionally, the eNodeB 2021 may be connected to other eNodeBs 2022 through a backhaul (such as the X2 interface), the eNodeB 2021 is connected to the EPC 203, and the eNodeB 2021 can provide access for the UE 201 to the EPC 203.

[0060] The EPC 203 may include an MME (Mobility Management Entity) 2031, an HSS (Home Subscriber Server) 2032, other MMEs 2033, an SGW (Serving Gateway) 2034, a PGW (PDN Gateway) 2035, a PCRF (Policy and Charging Rules Function) 2036, etc. Optionally, the MME 2031 is a control node that processes the signaling between the UE 201 and the EPC 203 and provides bearer and connection management. The HSS 2032 is used to provide some registers to manage functions such as a home location register (not shown in the figure) and stores some user-specific information such as service characteristics and data rates. All user data can be sent through the SGW 2034. The PGW 2035 can provide IP address allocation for the UE 201 and other functions. The PCRF 2036 is a policy and charging control policy decision point for service data flows and IP bearer resources, and it selects and provides available policy and charging control decisions for a policy and charging enforcement functional unit (not shown in the figure).

[0061] The IP service 204 may include the Internet, an intranet, an IMS (IP Multimedia Subsystem), or other IP services, etc.

[0062] Although the above has been introduced by taking the LTE system as an example, those skilled in the art should be aware that this application is not only applicable to the LTE system, but also applicable to other wireless communication systems, such as GSM, CDMA2000, WCDMA, TD-SCDMA, 5G, and future new network systems (such as 6G), etc., which are not limited here.

[0063] Based on the above intelligent terminal hardware structure and communication network system, each embodiment of this application is proposed.

[0064] Figure 3 is a partial structural schematic diagram of the image sensor of this application, as Figure 3 shown, the image sensor includes a semiconductor substrate 12 and a lens array 13. Pixel photosensitive units 121 are arranged in an array on the semiconductor substrate 12; the lens array 13 is arranged in the light incident direction of the photosensitive array formed by the pixel photosensitive units 121. The lens array 13 includes a plurality of microlenses 131 corresponding to each pixel photosensitive unit 121. The microlens 131 includes a light condensing part 1311 for condensing light and a light enhancing part 1312 for reflecting and refracting light. The light is incident on the pixel photosensitive unit 121 after passing through the light condensing part 1311 and the light enhancing part 1312. The image sensor of this application is a front-illuminated image sensor.

[0065] The microlens 131 of the image sensor of this application uses the light condensing part 1311 to gather light and uses the light enhancing part 1312 to reflect and refract light multiple times, which can multiply improve the light efficiency, improve the shooting effect of the pixel photosensitive unit 121 in a dark and low-light environment, reduce image noise, and thus improve the image quality. Since the outer wall of the light enhancing part 1312 of this application satisfies the total internal reflection design of light, the light is directly incident on the pixel photosensitive unit 121 after passing through the light condensing part 1311 and the light enhancing part 1312, and there will be no extra light irradiating on the adjacent pixel photosensitive unit 121, avoiding the problem of light crosstalk.

[0066] Optionally, the light incident surface of the light condensing part 1311 is a spherical surface convex in the direction away from the light enhancing part 1312.

[0067] Optionally, the light output surface of the light condensing part 1311 is in contact with the light incident surface of the light enhancing part 1312.

[0068] Optionally, the light output surface of the light enhancing part 1312 is convex in the direction away from the light condensing part 1311.

[0069] Optionally, as Figure 3As shown, the light condensing part 1311 is in the shape of a convex lens; the light intensifying part 1312 is in the shape of a bowl. The light intensifying part 1312 of the present application imitates the retinal structure of the elephant nose fish, and the retinal structure of the elephant nose fish can increase the light concentration by 525%.

[0070] Optionally, as Figure 3 shown, the edge of the light incident surface of the light intensifying part 1312 is the light incident end, the edge of the light emitting surface of the light intensifying part 1312 is the light emitting end, and the outer diameter of the light intensifying part 1312 gradually decreases from the light incident end towards the direction close to the light emitting end.

[0071] Optionally, the light emitting surface of the light condensing part 1311 is a first plane.

[0072] Optionally, the light incident surface of the light intensifying part 1312 is a second plane parallel to the first plane.

[0073] Optionally, the areas / shapes of the first plane and the second plane are the same.

[0074] Optionally, the central area of the light emitting surface of the light intensifying part 1312 is a third plane parallel to the first plane.

[0075] Optionally, the image sensor further includes a color film unit 141 disposed between the semiconductor substrate 12 and the lens array 13, and each light filtering unit 141 is disposed corresponding to a single pixel photosensitive unit 121.

[0076] Optionally, Figure 4 is a schematic structural diagram of the micro-lenses of the present application approaching the optical center of the semiconductor substrate. As Figure 4 shown, a plurality of first center lines are defined to vertically pass through the optical centers of the respective micro-lenses 131, a plurality of second center lines are defined to vertically pass through the optical centers of the respective light filtering units 141, and the distance between the first center line and the second center line of each pixel 121 gradually increases from the edge of the semiconductor substrate 12 towards the direction close to its optical center. The lens array 13 of the present application is offset towards the optical center of the semiconductor substrate 12, which can satisfy more light refraction and light energy concentration.

[0077] Optionally, the light condensing part 1311 and the light intensifying part 1312 are integrally formed.

[0078] Optionally, the semiconductor substrate 12 is a silicon material doped with a p-type dopant such as boron, or a silicon doped with an n-type dopant such as phosphorus or arsenic, or includes other elemental semiconductors such as germanium. In the embodiment of the present invention, the semiconductor substrate 12 is a silicon substrate and a P-type epitaxial layer formed on the silicon substrate, wherein the pixel 121 regions and each device are fabricated in the P-type epitaxial layer.

[0079] Optionally, Figure 5 is a schematic structural diagram of the pixel circuit of the image sensor according to an embodiment of the present application, asFigure 5 As shown, the pixel photosensitive unit 131 includes a photosensitive portion PD, a transfer transistor TX, a floating diffusion region FD, a reset transistor RST, and a source follower transistor SF. The photosensitive portion PD is configured to convert an optical signal containing image information into an electrical signal during an exposure process; the transfer transistor TX is connected to the photosensitive portion PD and the floating diffusion region FD and is configured to transfer the electrical signal of the photosensitive portion PD to the floating diffusion region FD; the source follower transistor SF is configured to output the electrical signal of the floating diffusion region FD; and the reset transistor RST is configured to reset the floating diffusion region FD. The semiconductor substrate 12 is doped, for example, by plasma implantation, such that source and drain electrodes of the photosensitive portion PD, the floating diffusion region FD, the transfer transistor TX, the source follower transistor SF, the reset transistor RST, and the selection transistor RS are formed within the semiconductor substrate 12.

[0080] Optionally, as Figure 5 shown, the pixel photosensitive unit 131 further includes a selection transistor RS. The selection transistor RS is configured to selectively output the electrical signal output by the source follower transistor SF to a column line (Pixel out).

[0081] Optionally, Figure 6 is a schematic diagram of a pixel circuit structure of an image sensor according to another embodiment of the present application. As Figure 6 shown, the pixel photosensitive unit 131 further includes a dual conversion gain transistor DCG. The dual conversion gain transistor DCG is connected between the reset transistor RST and the floating diffusion region FD. The dual conversion gain transistor DCG is configured to increase the full well capacity of the photosensitive portion PD during exposure. When the image sensor operates in a normal exposure environment, the dual conversion gain transistor DCG is turned off and the reset transistor RST is turned on, and the photosensitive portion PD is normally exposed; when the image sensor operates in a high exposure environment, the dual conversion gain transistor DCG is turned on and the reset transistor RST is turned off. At this time, the drain of the dual conversion gain transistor DCG is connected to a capacitor C, thereby increasing the full well capacity, which is beneficial to improving the dynamic range of the image sensor (the number of electrons received by the floating diffusion region FD increases and the signal-to-noise ratio is higher), and further improving the image quality.

[0082] The present application also relates to an intelligent terminal including the above-mentioned image sensor.

[0083] For the structure and functions of the intelligent terminal, please refer to the above, and details are not described herein again.

[0084] It can be understood that the above scenarios are only examples and do not constitute a limitation on the application scenarios of the technical solutions provided by the embodiments of the present application. The technical solutions of the present application can also be applied to other scenarios. For example, as is known to those of ordinary skill in the art, with the evolution of the system architecture and the emergence of new service scenarios, the technical solutions provided by the embodiments of the present application are equally applicable to similar technical problems.

[0085] The serial numbers of the embodiments of the present application above are only for description and do not represent the superiority or inferiority of the embodiments.

[0086] The steps in the method of the embodiments of the present application can be adjusted in order, combined, and deleted according to actual needs.

[0087] The units in the devices of the embodiments of the present application can be combined, divided, and deleted according to actual needs.

[0088] In the present application, for the description of the same or similar term concepts, technical solutions, and / or application scenarios, generally only the first occurrence is described in detail. When they appear repeatedly later, for the sake of brevity, they are generally not described again. When understanding the technical solutions and other contents of the present application, for the same or similar term concepts, technical solutions, and / or application scenarios that are not described in detail later, reference can be made to their relevant detailed descriptions before.

[0089] In the present application, the descriptions of the various embodiments have their own emphases. For the parts not described in detail or recorded in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0090] The technical features of the technical solutions of the present application can be combined arbitrarily. For the sake of concise description, not all possible combinations of the various technical features in the above embodiments are described. However, as long as the combinations of these technical features do not conflict, they should all be considered as the scope recorded in the present application.

[0091] Through the description of the above embodiments, those skilled in the art can clearly understand that the above embodiment methods can be implemented by means of software plus a necessary general hardware platform. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on such an understanding, the essence of the technical solution of the present application or the part that contributes to the prior art can be embodied in the form of a software product. This computer software product is stored in a storage medium as above (such as ROM / RAM, magnetic disk, optical disc), and includes several instructions to enable a terminal device (which can be a mobile phone, computer, server, controlled terminal, or network device, etc.) to execute the methods of each embodiment of the present application.

[0092] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware, or any combination thereof. When implemented using software, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the processes or functions according to the embodiments of the present application are generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable devices. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center by wire (such as coaxial cable, optical fiber, digital subscriber line) or wirelessly (such as infrared, wireless, microwave, etc.). The computer-readable storage medium can be any available medium that can be accessed by a computer or a data storage device such as a server or data center that includes one or more integrated available media. The available medium can be a magnetic medium (such as a floppy disk, storage disk, magnetic tape), an optical medium (such as a DVD), or a semiconductor medium (such as a solid-state disk (SSD)), etc.

[0093] The above are only the preferred embodiments of the present application, and do not limit the patent scope of the present application. Any equivalent structural or equivalent process transformations made using the content of the specification and drawings of the present application, or directly or indirectly applied in other related technical fields, are similarly included in the patent protection scope of the present application.

Claims

1. An image sensor, characterized in that: It includes a semiconductor substrate and a lens array, wherein pixel photosensitive units are arranged in an array on the semiconductor substrate; the lens array is arranged in the light incident direction of the photosensitive array composed of the pixel photosensitive units, and the microlenses of the lens array include a focusing part for converging light and a light-enhancing part for reflecting and refracting light, and the light passes through the focusing part and the light-enhancing part and is incident on the pixel photosensitive units.

2. The image sensor according to claim 1, wherein: The light incident surface of the light focusing portion is a spherical surface convex in a direction away from the light increasing portion; The light emitting surface of the light focusing portion is in contact with the light incident surface of the light increasing portion; The light-emitting surface of the light-enhancing portion protrudes in a direction away from the light-collecting portion.

3. The image sensor according to claim 2, wherein: The edge of the light incident surface of the light enhancing portion is the light incident end, the edge of the light emitting surface of the light enhancing portion is the light emitting end, and the outer diameter of the light enhancing portion gradually decreases from the light incident end toward the light emitting end.

4. The image sensor according to claim 3, wherein: Include at least one of the following: The light emitting surface of the light focusing portion is a first plane; The light incident surface of the light-enhancing portion is a second plane parallel to the first plane; The first plane and the second plane have the same area and / or shape; The central area of ​​the light emitting surface of the light-enhancing portion is a third plane parallel to the first plane.

5. The image sensor according to claim 1, wherein: The image sensor further includes a filter unit disposed between the semiconductor substrate and the lens array, and each of the filter units is disposed corresponding to a single pixel photosensitive unit.

6. The image sensor according to claim 5, characterized in that A plurality of first center lines are defined to pass perpendicularly through the optical center of each microlens, and a plurality of second center lines are defined to pass perpendicularly through the optical center of each filter unit, and the distance between the first center line and the second center line of each pixel gradually increases from the edge of the semiconductor substrate toward the direction close to the optical center thereof.

7. The image sensor according to any one of claims 1 to 6, characterized in that: The pixel photosensing unit includes a photosensing part, a transfer transistor, a floating diffusion area, a reset transistor and a source follower transistor. The photosensing part is used to convert the light signal containing image information into an electrical signal during the exposure process; the transfer transistor connects the photosensing part and the floating diffusion area, and is used to transfer the electrical signal of the photosensing part to the floating diffusion area; the source follower transistor is used to output the electrical signal of the floating diffusion area; and the reset transistor is used to reset the floating diffusion area.

8. The image sensor according to claim 7, wherein: The pixel photosensitive unit further includes a selection transistor, which is used to select and output the electrical signal output by the source follower transistor to a column line.

9. The image sensor according to claim 7, wherein: The pixel photosensitive unit also includes a dual conversion gain transistor, which is connected between the reset transistor and the floating diffusion area, and is used to increase the full well capacity of the photosensitive part during exposure.

10. An intelligent terminal, characterized in that: The image sensor comprises the image sensor according to any one of claims 1 to 9.

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