**Advanced Streaming Format (ASF)**
ASF stands for Advanced Streaming Format, a file compression format designed for streaming video content over the internet. It uses the MPEG-4 compression algorithm, offering high compression rates and good image quality. As a streaming format, it allows real-time playback without needing to download the entire file first. While its image quality may not match that of VCDs, it is superior to RAM formats. Its main advantage lies in its ability to deliver smooth video experiences even with limited bandwidth.
**Audio Video Interleaved (AVI)**
AVI, short for Audio Video Interleaved, is an older video format developed by Microsoft during the Windows 3.1 era. It is known for its compatibility, ease of use, and high-quality video output. However, AVI files tend to be large in size due to minimal compression, making them less suitable for web-based streaming or storage on limited space devices.
**Standard Video Signal**
A standard video signal refers to a video input that follows a specific encoding format, typically using RCA connectors. The signal is compressed at the source and decoded upon reception, which can lead to some loss of quality. This format is commonly used in analog television systems and is often found in consumer electronics like VCRs and older televisions.
**CCD Size**
The CCD (Charge-Coupled Device) size refers to the diagonal dimension of the light-sensitive area on the sensor. Common sizes include 1/2 inch, 1/3 inch, and 2/3 inch. Larger CCDs generally offer better low-light performance and image quality, but smaller sizes are more common in modern security cameras due to cost and design considerations.
**Lens Image Size**
Lens image size specifies the diameter of the image circle that the lens can project onto the camera’s sensor. Common sizes include 25.4mm (1 inch), 16.9mm (2/3 inch), 12.7mm (1/2 inch), 8.47mm (1/3 inch), and 6.35mm (1/4 inch). Matching the lens image size with the camera’s sensor size ensures optimal image quality and minimizes distortion.
**Magnetic Focusing**
Magnetic focusing is a technique used in cathode ray tubes (CRTs) to converge electron beams using magnetic fields. It helps in directing the beam precisely to the correct point on the screen, ensuring accurate image formation.
**DIVX**
DIVX is a video compression format that was developed as a competitor to DVD. It uses the MPEG-4 algorithm and offers high-quality video at a lower file size than traditional DVDs. One of its key advantages is that it can be played on standard CD-ROM drives, eliminating the need for a DVD player. DIVX also requires relatively modest hardware specifications, making it accessible on older computers.
**Low-Frequency Distortion**
Low-frequency distortion occurs when the signal contains unwanted changes in waveform at frequencies below 15.75 kHz. This type of distortion is common in TV systems and can affect the clarity and stability of the displayed image.
**Low-Light Camera (LLL Camera)**
Low-light cameras are specially designed to capture clear images in very dim lighting conditions. These cameras are essential in surveillance applications where lighting is limited, such as night-time monitoring or indoor environments with poor illumination.
**Electrical Distortion**
Electrical distortion refers to any undesired change in the shape of a signal compared to the original. It can occur due to various factors, including component imperfections, power fluctuations, or interference, and can degrade the quality of the video or audio output.
**Dot Signal Generator**
A dot signal generator produces special spot signals used to test the scanning linearity and geometric distortion of television cameras and monitors. It is an essential tool in calibrating display equipment to ensure accurate image reproduction.
**Electromagnetic Focusing**
Electromagnetic focusing is a method used in electronic lenses to direct electron beams using electromagnetic fields. It involves the use of deflection coils to control the path of the beams, ensuring precise focus on the image plane.
**Dynamic Range**
Dynamic range in television systems refers to the range of brightness levels a camera can capture in a single frame. A higher dynamic range means the camera can accurately represent both bright and dark areas of a scene, preserving details in shadows and highlights.
**Jitter**
Jitter refers to variations in the timing of a signal caused by mechanical disturbances, power supply instability, or component characteristics. It can result in amplitude or phase fluctuations, affecting the quality of the transmitted video or audio.
**EIA Interface**
The EIA interface is a set of standards defined by the Electronic Industries Association (EIA) that specify signal characteristics such as duration, waveform, voltage, and current. These standards ensure compatibility between different video and audio devices.
**EIA Sync Signal**
EIA sync signals are used to synchronize the scanning process in television systems. They include standards like RS-170, RS-170A, RS-312, and others, ensuring that video signals are properly timed across different components.
**F-Number (F-Value)**
The F-number is the ratio of a lens's focal length to the diameter of its entrance pupil. A lower F-number indicates a larger aperture, allowing more light to enter the lens and improving low-light performance. It is a key factor in determining the depth of field and exposure in photography.
**Load**
In electronics, a load refers to the part of a system that consumes energy from a device. It can be a resistor, motor, or any other component that draws power from the source.
**Magnification**
Magnification is the ratio of the size of an object to the size of its image. It is typically based on a 1-inch focal length lens and a 1-inch target size. Magnification affects how much of a scene is captured and how detailed the image appears.
**Interference**
Interference occurs when unwanted signals disrupt the intended signal, causing degradation in quality. It can come from external sources such as electrical noise, radio waves, or other electronic devices operating in the same frequency range.
**Isolation Amplifier**
An isolation amplifier is designed to prevent interference between input and output circuits. It ensures that signals remain clean and unaffected by external noise or fluctuations.
**Interlacing (2:1)**
Interlacing is a scanning technique used in television systems where each frame is divided into two fields. These fields are scanned alternately, reducing the perceived flicker and improving motion handling. It is commonly used in NTSC and PAL systems.
**Light**
Light is a form of electromagnetic radiation that is visible to the human eye. It has wavelengths ranging from approximately 400 nm (blue) to 750 nm (red). Light is essential for vision and plays a critical role in imaging and display technologies.
**Luminous Flux**
Luminous flux is the measure of the total amount of visible light emitted by a source per unit of time. It is expressed in lumens and is used to quantify the brightness of a light source.
**Aperture (Iris)**
The aperture, or iris, is an adjustable opening in a camera lens that controls the amount of light entering the lens. A larger aperture (smaller F-number) allows more light in, improving low-light performance.
**Optical Distortion**
Optical distortion refers to any deviation from the true representation of an object in an image. Common types include barrel distortion, pincushion distortion, and chromatic aberration. It can be corrected through software or specialized lens designs.
**Infrared Radiation**
Infrared radiation is a type of electromagnetic radiation with wavelengths longer than visible light but shorter than microwaves. It is invisible to the human eye but can be detected by thermal sensors and is used in remote sensing, night vision, and communication systems.
**Echo**
An echo is a reflected signal that arrives at the receiver after the original signal. It can cause ghosting or delayed audio effects, especially in environments with reflective surfaces or long transmission paths.
**IP Protection Rating**
The IP rating indicates the level of protection a device offers against dust and water. It consists of two digits: the first for solid particle resistance, and the second for liquid resistance. For example, IP55 means the device is protected against dust and low-pressure water jets.
**Laser**
A laser is a device that emits coherent light through a process called stimulated emission. It uses an optical resonator with mirrors and a gain medium to amplify light. Lasers are used in a wide range of applications, from medical treatments to data storage and communication.
**Focal Length (FL)**
Focal length is the distance from the lens center to the point where light converges to form a sharp image. It determines the angle of view and magnification of the image. Shorter focal lengths provide wider angles, while longer ones offer narrower, more zoomed-in views.
**Focal Length and Field of View**
The focal length of a lens directly affects the field of view. A shorter focal length results in a wider field of view, while a longer one narrows it. This is crucial in surveillance and photography, where the desired coverage and detail must be balanced.
**Focal Plane**
The focal plane is the surface where the image is formed by the lens. It is perpendicular to the optical axis and is where the sensor or film is placed to capture the image.
**Lens**
A lens is an optical component made of glass or plastic that focuses light to form an image. It can be used to gather or disperse light, creating either a real or virtual image of the subject. Lenses are essential in cameras, microscopes, and other optical instruments.
**Lens Speed / F-Number**
Lens speed refers to the maximum aperture of a lens, determined by the F-number. A lower F-number indicates a faster lens, capable of capturing more light and performing better in low-light conditions.
**Electrostatic Focusing**
Electrostatic focusing is a method used in cathode ray tubes to focus the electron beam using electric fields. It involves applying voltage to specific elements within the lens system to control the beam's path.
**Variable Iris (Iris Diaphragm)**
A variable iris is a mechanism inside a lens that adjusts the size of the aperture. It allows for manual or automatic control of the amount of light entering the lens, affecting exposure and depth of field.
**Lux**
Lux is the SI unit of illuminance, measuring the amount of light falling on a surface. One lux equals one lumen per square meter. It is used to quantify the brightness of a light source in relation to the area it illuminates.
**Luminance Signal**
The luminance signal in a color television system represents the brightness or intensity of the image. It is separate from the chrominance signal, which carries color information, and is essential for producing a clear and well-defined image.
**Lumen (Im)**
A lumen is the unit of luminous flux, representing the total amount of visible light emitted by a source. It measures how much light is produced, rather than how it is distributed across a surface.
**MPEG (Moving Picture Experts Group)**
MPEG is a set of standards for video and audio compression. It includes MPEG-1, MPEG-2, and MPEG-4. MPEG-1 is widely used for VCDs and online video, while MPEG-2 is used for DVDs and HDTV. MPEG-4 offers higher compression efficiency and supports streaming and interactive media.
**nAVI (New AVI)**
nAVI is a modified version of the ASF format, designed to improve video playback performance. It offers higher frame rates but sacrifices some of the streaming capabilities of the original ASF format.
**NTSC (National Television Systems Committee)**
NTSC is a television standard used primarily in North America, Japan, and parts of South America. It has a resolution of 525 lines and a refresh rate of 60 Hz, providing a stable and consistent image for broadcast and consumer electronics.
**PAL (Phase Alternating Line)**
PAL is a color television standard used in Europe, Australia, and many Asian countries. It has a resolution of 625 lines and a refresh rate of 50 Hz. Unlike NTSC, it is less sensitive to phase errors, resulting in more stable color reproduction.
**QuickTime**
QuickTime is a multimedia framework developed by Apple, supporting video, audio, and animation. It is known for its high-quality compression and cross-platform compatibility, making it a popular choice for video editing and playback.
**QCIF (Quarter Common Intermediate Format)**
QCIF is a standardized image format used in video conferencing and mobile applications. It has a resolution of 176×144 pixels and is commonly used in H.323 protocols for video transmission.
**QSIF (Quarter Size Standard Image Format)**
QSIF is a smaller image format, about 25% the size of SIF. It is used in applications requiring lower resolution and reduced bandwidth, such as video conferencing and mobile communications.
**Leading Edge**
The leading edge of a pulse refers to the rising portion of the signal, typically measured between 10% and 90% of the total amplitude. It is important in timing and synchronization applications.
**Diopter**
A diopter is a unit of measurement for the optical power of a lens. It is calculated as the reciprocal of the focal length in meters. For example, a 25 cm focal length lens has a diopter value of 4.
**Drive Pulses**
Drive pulses are synchronization and blanking signals used in television systems to control the scanning process. They ensure that the image is displayed correctly on the screen.
**RealVideo (RA/RAM)**
RealVideo is a streaming video format developed by RealNetworks. It is optimized for low-bandwidth environments, allowing continuous playback over dial-up connections. While not as high-quality as other formats, it remains popular for web-based video delivery.
**Incident Light**
Incident light is the light that falls directly on an object. It is the primary source of illumination in photography and video, influencing the exposure and appearance of the image.
**Softening**
Softening is a technique used to reduce the sharpness of edges in an image, often applied during compression to minimize blocky artifacts. It improves visual quality without significantly increasing file size.
**Source Video**
Source video refers to the original footage used in digital editing and compression processes. It can come from various sources, such as tapes, disks, or digital files, and serves as the basis for further processing.
**Source Video Device**
A source video device is any equipment that provides the original video signal, such as VCRs, DVD players, or camcorders. It is essential for capturing and transmitting video content to editing systems or displays.
**SQCIF (Sub-Quarter CIF)**
SQCIF is a smaller image format, with a resolution of 128×96 pixels. It is used in applications requiring very low resolution, such as mobile video calls or low-bandwidth transmissions.
**S-Video Input**
S-Video input provides a higher quality video signal compared to composite video by separating the chrominance and luminance components. This reduces cross-color interference and improves overall image clarity.
**SIF (Standard Image Format)**
SIF is a standard image format used in MPEG-1 compression. It has a resolution of 352×288 pixels for PAL and 350×240 pixels for NTSC. It is commonly used in video conferencing and digital video applications.
**Camera**
A camera is a device that captures images using a CCD or CMOS sensor. It includes a lens, image processing circuitry, and a power supply. Modern cameras are used in surveillance, broadcasting, and consumer electronics, with black-and-white models still preferred for low-light applications.
**Camera Image Signal-to-Noise Ratio (SNR)**
The SNR of a camera is the ratio of the video signal to the noise present in the image. A higher SNR results in a cleaner, more detailed image, while a lower SNR leads to grainy or noisy output. It is measured in decibels (dB).
**Field of View**
The field of view of a lens is the angle at which it captures the scene. It depends on the focal length and the size of the camera’s sensor. A wider field of view is suitable for panoramic shots, while a narrower one is ideal for close-ups.
**Video**
Video refers to the recording and playback of moving images. It can be analog or digital and is used in television, cinema, and digital media. Video signals contain both visual and audio components, which are processed and transmitted separately.
**Video Driver (VD)**
A video driver is a component that controls the auto-iris lens by adjusting the aperture based on the camera’s output. It ensures proper exposure and image quality under varying lighting conditions.
**Video Capture Card**
A video capture card is a device that converts analog video signals into digital format for storage or processing on a computer. It often includes compression features to reduce the data load on the system.
**Video Overlay**
Video overlay is the process of combining computer-generated graphics with live video signals. It is used in applications such as on-screen displays, captions, and augmented reality.
**Loss**
Loss refers to the reduction in signal strength or quality, often expressed in decibels (dB). It can occur due to transmission, filtering, or other factors affecting the integrity of the signal.
**Interlace, Random**
Random interlacing is a scanning technique where the two fields of a frame are not synchronized, leading to potential image instability or distortion. It is less common than standard interlacing and is typically used in specific applications.
**Fresnel Lens**
A Fresnel lens is a lightweight, flat lens composed of concentric rings that focus light efficiently. It is used in applications such as lighthouses, projectors, and solar concentrators.
**Image Plane**
The image plane is the surface where the image is formed by the lens. It is perpendicular to the optical axis and is where the sensor or film is positioned to capture the image.
**Visual Component (Screen Component)**
The visual component of a video signal refers to the image itself, separate from the audio component. It is what the viewer sees on the screen and is essential for delivering a complete multimedia experience.
**Differential Gain**
Differential gain measures the change in the amplitude of a color subcarrier as the video signal varies from black to white. It is an indicator of the consistency of color reproduction in a system.
**Differential Phase**
Differential phase measures the change in the phase of a color subcarrier as the video signal varies from black to white. It is another important parameter in assessing the quality of color reproduction.
**Relative Aperture**
The relative aperture of a lens is the ratio of the effective aperture diameter to the focal length. It determines the amount of light entering the lens and is inversely related to the F-number.
**Number of Pixels**
The number of pixels in a camera’s sensor determines its resolution. More pixels generally mean higher resolution and better image detail, although this also increases file size and processing requirements.
**Signal-to-Noise Ratio (SNR)**
SNR is the ratio of the signal strength to the background noise, measured in decibels (dB). A higher SNR results in a clearer and more detailed image, while a lower SNR can lead to visible noise or graininess.
**Line Amplifier**
A line amplifier is a device that boosts the strength of a signal as it travels along a transmission line. It is used to compensate for signal loss over long distances.
**Linearity**
Linearity refers to the proportional relationship between the input and output signals in a system. A linear system ensures that the output accurately reflects the input without distortion.
**Line Pairs**
Line pairs are a measure of resolution in television systems. One line pair consists of a black and a white line. Higher line pairs indicate better resolution and image clarity.
**Limited Resolution**
Limited resolution is a measure of how many distinguishable lines can be seen in a test pattern. It is used to evaluate the performance of video systems and display devices.
**Intensified CCD (ICCD)**
An intensified CCD is a type of camera that uses an electron multiplier to enhance low-light performance. It is used in scientific and surveillance applications where extreme sensitivity is required.
**Intensified Silicon Intensified Target (ISIT)**
ISIT is a type of image intensifier used in low-light cameras. It amplifies the incoming light before it reaches the sensor, significantly improving sensitivity and image quality in dark environments.
**Luminance**
Luminance refers to the brightness of a scene as measured by the camera. It is an important parameter in determining the minimum illumination required for proper image capture.
**Frame**
A frame is a single still image in a sequence of video frames. In television systems, frames are displayed at a rate of 25 per second for PAL and 30 per second for NTSC.
**Frame Rate**
Frame rate is the number of frames displayed per second, measured in frames per second (fps). A higher frame rate results in smoother motion and is essential for capturing fast-moving scenes.
**DC Driver (DD Driver)**
A DC driver is a type of lens control system that uses direct current to adjust the aperture. It is commonly used in professional cameras and offers precise control over exposure settings.
**Lag**
Lag refers to a delay or pause in the image formation within a TV pick-up tube. It occurs when the charge map of multiple frames is briefly held after the excitation is removed.
**Progressive Scan**
Progressive scan is a method of displaying video where all the lines of a frame are drawn sequentially, rather than in alternating fields. It results in a smoother and more detailed image, especially for fast-moving content.
**Impedance**
Impedance is a measure of the opposition to the flow of alternating current in a circuit. It is expressed in ohms and is crucial for ensuring proper signal transmission between devices.
This revised content expands on the original text, adds additional context, and presents the information in a more natural, human-like tone while maintaining technical accuracy.
P20*P20 Transparent LED Screen
P20*P20 Transparent Led Screen,P20 Led Transparent Display Screen,P20 Transparent Led Screen,Transparent Led Display
Shenzhen YuGuang New Material Co.,Ltd , https://www.ygsmartfilm.com