1. What is camera module
Definition: A camera, also known as a computer camera, computer eye, etc., belongs to a video input device and is used in video conferencing, real-time monitoring, telemedicine, mobile phones, PDA Tablet PC, etc. Cameras are mostly used in communication equipment, people conduct real-time conversations and communicate through cameras. In addition, people can also use them for various popular digital images, audio-visual processing, etc. The camera module usually refers to the composition of the internal structure except for the product shell, which is called a module, abbreviated as CCM, which can be understood as Compact Camera Module, CMOS Camera Module, or Cellphone Camera Module.
Working principle: The working principle of the camera module is very simple, as a rough rule, the lens focuses the reflected light emitted by the object to be photographed on the sensor surface after being filtered by the filter. The optical signal is converted into an electrical signal by the image sensor, and then the electrical signal is converted into a digital signal through A/D, after that the digital signal is output to the ISP or DSP after the signal is processed and decoded by DSP, it is restored to the image of the object to be photographed. If the sensor does not integrate DSP, it is transmitted to the processor through DVP, and the data format at this time is Raw RGB. If the DSP is integrated, the Raw data is processed by the system and the data in YUV or RGB format is output.
Basic composition: The basic composition of the camera module includes an optical lens (Lens), an image sensor (Sensor), peripheral electronic components, a connector (Connector), a printed circuit board (PCB), and a lens holder (Lens Holder). The most important parts are the optical lens and the image sensor. Some image sensors integrate DSP, and some do not. However, modules without integrated DSP will need to connect DSP externally.
Lens: It is composed of a refraction layer and a filter. The refraction layer has a multi-layer structure, which is mixed with glass or plastic or glass-plastic. The refraction layer completes multiple refractions of light and then projects it to the photosensitive chip. The filter is used to filter out some light that can be observed by the naked eye and can affect the color effect band.
Photosensitive chip: It mainly collects the light folded by the lens and concentrates the light. At present, there are two kinds of packages: plastic and ceramic. The photosensitive area is divided into different sizes. The larger the photosensitive area, the lighter collected, and the unit pixel The higher it is, the better the result will be.
Integrated Circuit Board: An essential part of all electronic devices. The structure is complex and consists of a variety of electronic material components and main control processing chips (DSP). The electronic components mainly play the roles of controlling voltage, reducing power consumption, and filtering interference impurities. The main control processing chip plays a huge role, similar to the CPU of a computer. It mainly compresses and organizes the color data transmitted by the chip and optimizes the effect. Therefore, the computing power of the main control chip plays an important role in the image quality effect presented by the camera module.
The basic components of the camera module are composed of the above three parts, other required structural components are superimposed according to the functions and effects that an imaging device needs to achieve such as adding light panels to enhance the night vision effects, IR-CUT in order to apply to complex environmental changes etc.
2. Function of camera module
After the lens captures the image, the photosensitive component circuit and control component in the camera module process the image and convert it into a digital signal, further the digital signal is processed by DSP and converted into standard RGB, YUV and other format image signals for storage on the device, finally the image could be presented through displayer. The camera module generally has basic functions such as video recording/distribution and still image capture.
3. Application of camera module
Camera modules have a wide range of applications. For example, common applications include video conferencing, face recognition, living inspection, authentication and identification, and scanning and filing. All these must be applied to the industrial-grade camera module, because it has high recognition, high definition and no distortion, and can truly restore the shooting scene, so the camera module is the most popular monitoring equipment for industrial-grade applications. It can be said that the camera module is the most basic monitoring component, it can also be called a monitoring camera without a casing.
4. Types of camera modules
The classification of camera modules varies with structure and performance.
Classification by output method: FTB, BTB, Socket, SMT (SMD module), etc.;
Classification by focusing method: FF (Fix Focus) module, AF (Auto Focus) module, Zoom module;
Classification by pixel: 0.1MP (CIF) module, 0.3MP (VGA) module, 1.3MP (SXGA) module, 2.0MP (UXGA) module, 3.0MP (QXGA) module, 5.0MP (QSXGA) module group, etc.;
Classified by process: CSP, COB, Reflow;
Classification by product type: mobile phone camera module, notebook camera module, car camera, security camera, endoscope module, barcode scanning engine, photoelectric navigation, etc.;
DVP is a parallel port. The maximum speed of all DVPs should be controlled below 72M, so the PCB layout will be better. 500W can barely use DVP, and 800W and above all use the MIPI interface.
MIPI cameras are commonly found in mobile phones and
tablets, and support high-definition resolutions of more than 5 million pixels. Its full name is "Mobile Industry Processor Interface", which is divided into MIPI DSI and MIPI CSI, corresponding to video display and video input standards respectively. At present, MIPI cameras are widely used in embedded products, such as driving recorders, body cameras, high-definition micro cameras, and network surveillance cameras. MIPI is a differential serial port transmission, which is fast and anti-interference. Mainstream mobile phone modules are now using MIPI transmission.
The USB camera module directly integrates the camera unit and the video capture unit and then connects to the HOST SYSTEM through the USB interface. Now the digital camera modules on the CAMERA market are basically based on the new USB2.0 interface for data transmission. Computers and other mobile devices are connected directly through the USB interface, plug and play.
USB Video Class (UVC) standard
The maximum transmission bandwidth of USB2.0 is 480Mbps (i.e 60MB/s)
Simple and cost-effective
Plug and Play
High compatibility and stability
higher dynamic range
The digital signal is output to the display after being processed by software on a standard operating system compatible with the UVC standard.
USB 3.0 camera module:
Compared with the USB 2.0 camera module, the USB 3.0 camera can achieve a higher transmission speed, and the USB 3.0 is fully compatible with the USB2.0 interface
The maximum transmission bandwidth of USB3.0 is up to 5.0Gbps (640MB/s)
9-pin definition vs. USB2.0 4-pin
Fully compatible with USB 2.0
Superfast connection
5. How to choose camera module
There are many kinds of camera modules on the market, and the specifications and prices are usually different. How to choose a camera module that adapts to the current application system is a very critical issue.
The most basic points to be clear:
1. Required resolution:
Generally speaking, it means the maximum image size that the camera can support, such as 640x480 (normal), 800x600, 1280x720 (HD), 1920x1080 (Full HD or ultra-clear), etc. Of course, the higher the resolution, the better, but the actual situation of the system must also be considered. If the system cannot use a resolution such as 1920x1080, there is no need to purchase such a high camera.
Generally, the video resolutions that may be applied are:
160x120, 4:3
320x240, 4:3
480x360, 4:3
640x480 (Pu Qing), 4:3 0.3M
800x600 (SD), 4:3 0.5M
960x720, 4:3. 0.7M
1280x720 (HD), 16:9 1M
1920x1080 (Full HD or Ultra HD) 16:9 2M
The camera can be configured to output images of several different resolutions. For example, the resolutions supported by a USB digital camera on the desktop in the YUYV output format are:
160x120, 320x240, 544x288, 640x480, 800x600, 960x720, 1280x720, 1280x960, If the software is configured to 480x360, and the camera does not support this resolution, it will choose the most similar one from the resolutions it supports, therefore it is better to choose the format of 544x288. If the software needs to input 480x360, and the hardware can only output 544x288, it needs to scale 544x288 to 480x360, which will increase the computational complexity and not be conducive to system optimization. Therefore, when choosing a camera, not only check the maximum resolution of the camera but also whether the different resolution files that the camera out
2. Frame rate:
Generally speaking, it means the highest video capture capability that the camera can support at the maximum resolution in a certain color space. Also taking the desktop USB camera as an example, it supports two color spaces YUYV and MJPEG. The results of testing frame rates in these two spaces are:
format = YUYV, input resolution = 160 x 120, v4l2 resolution = 160 x 120, fps = 23
format = YUYV, input resolution = 320 x 240, v4l2 resolution = 320 x 240, fps = 23
format = YUYV, input resolution = 480 x 360, v4l2 resolution = 544 x 288, fps = 23
format = YUYV, input resolution = 640 x 480, v4l2 resolution = 640 x 480, fps = 23
format = YUYV, input resolution = 800 x 600, v4l2 resolution = 800 x 600, fps = 16
format = YUYV, input resolution = 960 x 720, v4l2 resolution = 960 x 720, fps = 8
format = YUYV, input resolution = 1280 x 720, v4l2 resolution = 1280 x 720, fps = 9
format = YUYV, input resolution = 1920 x 1080, v4l2 resolution = 1280 x 960, fps = 4
format = MJPG, input resolution = 160 x 120, v4l2 resolution = 160 x 120, fps = 23
format = MJPG, input resolution = 320 x 240, v4l2 resolution = 320 x 240, fps = 23
format = MJPG, input resolution = 480 x 360, v4l2 resolution = 544 x 288, fps = 23
format = MJPG, input resolution = 640 x 480, v4l2 resolution = 640 x 480, fps = 23
format = MJPG, input resolution = 800 x 600, v4l2 resolution = 800 x 600, fps = 23
format = MJPG, input resolution = 960 x 720, v4l2 resolution = 960 x 720, fps = 23
format = MJPG, input resolution = 1280 x 720, v4l2 resolution = 1280 x 720, fps = 23
format = MJPG, input resolution = 1920 x 1080, v4l2 resolution = 1280 x 960, fps = 23
The frame rate is not necessarily the higher the better, it also depends on the system requirements. For general sports scenes, the frame rate of 15fps can already be regarded as continuous motion video by the human eye. At this time, if the camera supports a frame rate higher than 15fps, it can meet the needs of the system.
General camera parameters Video output mode: 1080P@30, 1080P@25, 1080P@24, 1080i@60, 1080i@50, 720P@60, 720P@50, where 24, 25, 30, 50, and 60 are the frame rates.
3. Viewing angle
Imaging formula 1/D + 1/d = 1/f. => D = d/(d/f - 1)
In the formula, D is the object distance; d is the image distance; f is the focal length of the lens. D is proportional to f.
The larger the focal length of the lens, the longer the effective viewing distance (telephoto), but the smaller the viewing angle;
The smaller the focal length of the lens, the closer the effective viewing distance, but the larger the viewing angle (wide angle).
Users need to choose cameras according to their actual application scenarios. For example, the 3.6MM lens used is a wide-angle lens, which has a wider viewing range and is suitable for small spaces (elevators, etc.). A telephoto lens (such as 12MM) is suitable for looking at a long distance, but at a relatively narrow angle of view. Therefore, wanting to see far and wide and clear at the same time cannot be achieved at the same time. The most suitable lens angle can only be determined according to the specific application.
4. Camera module connector interface
How to connect the camera module to the main board of the device? This involves the interface type of the camera module, is it MIPI, USB, or DVP interface?
For more issues that are to be considered, please refer to How to choose a camera module
6. How to customize a camera module
If the customer needs to customize a camera module according to the actual application, at least the following points need to be confirmed with the camera module manufacturer:
1. Whether there is a specified chip model, and further determine the compatibility of the camera chip with the motherboard of the customer equipment.
2. Pin Definition
3. Structural dimensions, the total length of the module
4. Imaging direction
5. Lens angle requirements, or other special requirements
6. Connector Type
7. Application scenarios
After clarifying the above points, the basic camera module prototype can be designed, and the other is image debugging optimization and detailed adjustment after testing.
For more customization steps, please refer to: How to Customize a Camera Module
7. China & Foreign Camera Modules suppliers
Global Competitive Camera Module Supplier Landscape
The major companies in the market include Cowell E Holdings Inc., Fujifilm Corporation, LG Innotek Co. Ltd, Samsung Electro-Mechanics Co. Ltd, Sony Corporation, Sunny Optical, O-Film, LUXVISIONS, etc. O-Film has become a mainstream supplier of dual-camera and multi-camera modules in the industry of its self-developed AA focusing process, highly automated production lines and mass-production competence. The market appears to be fragmented as it is highly competitive, market suppliers employ strategies such as product innovation and expansion to maintain market competitiveness.
from: Mordor Intelligence
In-vehicle camera modules market has major suppliers such as Autoliv Inc., Clarion Co. Ltd., Continental AG, Kappa optronics GmbH, LG Innotek, Magna International Inc., Mycronic AB, Robert Bosch GmbH, and Stonkam Co. Ltd. The competition is based on Price, quality and market share.
As a camera module manufacturer in China, in addition to manufacturing, custom-designed camera modules have always been CAMEMAKE's core competitive advantage. CAMEMAKE can design camera module prototype drawings for customers free of charge until it is confirmed, and could select suitable solutions according to the customer's cost budget. In addition, CAMEMAKE cooperates with original factory agents of well-known brand image sensors such as SONY, OmniVision, SAMSUNG, SUPERPIX, BYD, HIMAX, GLAXYCORE, etc. The core stable chip and raw material supply chain system ensures the stability of product price and delivery time, which is beneficial for customers to do market planning.
To know more about the customization camera types, kindly refer to: USB Camera Module
8.Conclusion
In short, when customers need a camera module, the most important thing is to find the corresponding professional product suppliers after understanding the basic information and application requirements of camera modules, The suppliers we are talking about here are not selling camera modules only, but also A long-term partner who could give customers professional product recommendations and could cooperate with customers in product upgrades at any time. CAMEMAKE would love to be your professional camera module customization consultant to help you choose the most suitable camera module.
