Label: Focus MCU
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The working steps of a digital camera are roughly as follows:
1. Boot preparation: When the camera's power is turned on, its internal master program starts to detect whether the components are normal. If a component is abnormal, the internal buzzer will sound an alarm or prompt an error message on the LCD and stop working. If everything is normal, it will be ready.
2, focusing and metering: digital cameras generally have auto focus and metering. When the DSC power is turned on, the camera's internal master program chip (MCU) immediately performs metering operations, exposure control and flash control, and shooting logic control. When the object is aligned and the shutter is pressed halfway, the MCU starts to work, and the image signal is transmitted to the CCD or CMOS through lens metering (TTL metering) and directly uses the voltage signal output from the CCD or CMOS as the focus signal, passing through the MCU. The calculation, comparison, calculation, determination of the distance of focus, shutter speed and aperture size, drive the AF and AE devices of the lens group to focus.
3. Image capture: After the focus and metering are completed, press the shutter again, and the camera (CCD or CMOS) captures the light reflected from the subject and stores it in three colors (colors) of red, green and blue. .
4, image processing: the captured image is A / D conversion, image processing, white balance processing, color correction, etc., and then combined into the storage area to form a complete digital image, after the image comes out and then through the DSP The unit is compressed and converted to JPEG format (still image compression mode) to save space.
5. Image storage: The image compressed by the image processing unit is sent to the memory for storage.
6. Image output: The image stored in the digital camera memory can be output to the computer through the output port, and can be graphically edited, processed, printed or transmitted online through an image processing program (software) in the computer.
Function: In the middle and advanced digital cameras, AE function and AF function are generally included.
1) AE function When the DSC camera is aimed at the subject, the CCD converts to the CCD digital voltage signal according to the brightness of the image transmitted from the lens. The DSP then performs the arithmetic processing according to the CCD digital voltage signal, and then transmits the operation result to The MCU quickly finds the optimum shutter speed and the optimal size of the lens aperture, and the MCU controls the AE mechanism for automatic exposure.
2) The AF function directly uses the digital voltage signal output by the CCD as the focus signal, and performs the forward and backward movement of the lens AF mechanism through the comparison of the operation of the MCU.
Classification: At present, there are many classifications of digital cameras. If they are divided by image sensors, they can be divided into CCD digital cameras and CMOS digital cameras.
CCD digital camera:
The CCD digital camera is an index code camera that uses a CCD image sensor to record images and is a medium to high file camera. The CCD itself cannot distinguish light of various colors, and it is used with color filters of different colors. Therefore, the CCD digital camera has the following two working modes:
1. The lens and the beam splitter are used to divide the light image signal into three colors of R, G and B, and respectively act on three CCDs. The three colors of light are converted into simulated electrical signals by CCD, and then converted by A/D. The device converts to a digital signal, which is then processed by the DSP digital signal processor and stored in the memory.
2. At the position of each pixel, there are three CCDs with R, G, and B color filters respectively. The light image signals after the lens are respectively applied to different sensors and converted into The electrical signal is simulated and then converted to a digital signal by an A/D converter, which is then processed by the DSP digital signal processor and stored in the memory.
CMOS digital camera:
A CMOS digital camera is an index code camera that uses a CMOS image sensor to record images. It works like a CCD digital camera and is currently a low-end camera.
CCD image sensor compared to CMOS image sensor:
The CMOS image sensor is easily integrated with an A/D circuit, a digital signal processor DSP circuit, and the like. The CCD image sensor can only latch the state of light to thousands of sampling points, and CMOS can perform many other functions such as A/D conversion, load signal processing, white balance processing and camera control (white Balance adjustment is the adjustment of the image so that the color of the photo taken under various lighting conditions is the same as the color of the scene seen by the human eye). In addition, the CMOS image sensor has the advantage of low power consumption, and its power consumption is about 1/10 of that of the CCD image sensor. However, CMOS image sensors are not as good as CCD image sensors in terms of resolution and color. The ability of images to have noise and accurately capture moving images is not strong.
Focus:
Focus is the premise of clear imaging, and digital cameras generally have an auto focus function. The auto focus function of a digital camera is similar to that of a conventional film camera, and it is also available in both active and passive forms.
Active is the camera actively emits infrared (or ultrasound), focusing according to the reflection of the target. Passive is the camera does not emit any rays and focuses according to the imaging of the target.
WIFI Antenna Description
Wi-Fi wireless networking works by sending radio transmissions on specific frequencies where listening devices can receive them. The necessary radio transmitters and receivers are built into Wi-Fi enabled equipment like routers, laptops, and phones. Antennas are key components of these radio communication systems, picking up incoming signals or radiating outgoing Wi-Fi signals. Some Wi-Fi antennas, particularly on routers, may be mounted externally, while others are embedded inside the device's hardware enclosure.
Wifi Antenna (2.4G Antenna) is one kind of wireless antennas.The main operating frequency of WLAN is 2.4Ghz and 5.8Ghz.
WiFi antenna(WLAN antenna)is installed on wireless devices like WLAN AP to reinforce signal strength.Wireless device will radiate signal in air at specified frequency 2.4Ghz or 5.8Ghz through WiFi antenna/WLAN antennas and allow other WLAN devices like NB or smartphone to get signal at same frequency range.
WLAN or WiFi is based on IEEE 802.11a,802.11b,802.11g,802.11n standards.WLAN or WiFi provides a connection through a WLAN AP,and this technology allows people can be connected to the networks within a coverage area.
WiFi Antenna specifications
Frequency range: 2400-2500Mhz
V.S.W.R : ≤1.5
Gain-dBi : 7
Polarization : Vertical
Impedance-Ω : 50
Max. Input Power-W : 50
Connector : SMA
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WIFI Antenna
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