By a DSP (Digital Signal Processing) chip and FPGA (field programmable gate array) as the core component of the wireless digital spread spectrum communication wireless spread spectrum communication platform is an open platform, can be used for wireless access, wireless images and audio transmission, mobile INTERNET, precise regional positioning LPS, intelligent remote detection and other high-tech fields. Based on the increase in the liquid crystal display and touch screen control, which can achieve a text and graphical information editing and wireless transmission.
We the FPGA logic programming lcd module controller functions. FPGA timer interrupt DSP (DSP about 5% of the working time) to access to external RAM display data, and then, FPGA internal logic of the display data to be displayed on the LCD screen. DSP on the touch screen conversion signal processing and computing, and complete a variety of text and graphics editing tasks. That together with the DSP and FPGA controls the liquid crystal display and text editing graphic information, and to receive a touch screen signal, in order to achieve the function of handheld pen. Character LCD
Modules Combined with digital spread spectrum wireless communications platform will be able to achieve a text and graphical information of the wireless transmission. The product can be used to reporters at the scene to conduct communications inconvenient text and graphics, real-time editing and coverage as well as in the process of moving text and graphic information required where wireless transmission
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2013年8月7日星期三
LCD driver control chip instruction decoding module design
The lcm module is a dedicated chip control center, the role of the decoder input from the MPU command word into a variety of high-level pulse having a constant width signal, thereby controlling the corresponding circuit, it changes state, complete control the corresponding function module.
MPU sent the script (with R / W, RS signal) into the instruction decoder decodes. The instruction decoder followed by a combinational logic circuit and a stabilizing signal is applied subsequent to the RS flip-flop, the flip-flop output control chip of the module operation.
The operation of the chip MPU total of 11 instructions, can be divided into four broad categories: display function setting command, address setting instructions, data transfer instructions and other type of instruction (such as reading BF).
① Display Function Set instruction includes three display mode: line 5 × 8 dot matrix, two lines of 5 × 8 dot matrix, line 5 × 11 dot matrix format; ② cursor display: do not show, flashing display, lit display; ③ left or right a display control; ④ shift display return after treatment; ⑤ clear the screen. With these instructions, the lcd module can be achieved in a variety of display control.
Address set instruction and data transfer instructions with the conduct, you can achieve MPU and data transfer between RAM. The MPU chip data transfer operation, first send the address set instruction, determine the selection DDRAM or CGRAM data transmission, and the address is written to the counter by setting the number of AC, the AC for RAM addressing operation. The MPU RAM read and write commands sent, can control the display character. MPU BF is an instruction detection, but does not require instruction decoding operations directly in MPU I / O port operation can be completed 3.1 has been introduced, not repeat them here. When the LCD drive control instruction to complete a chip, through the internal circuit generates a high signal BFRESET, the BF is reset, waiting for the next instruction.
MPU sent the script (with R / W, RS signal) into the instruction decoder decodes. The instruction decoder followed by a combinational logic circuit and a stabilizing signal is applied subsequent to the RS flip-flop, the flip-flop output control chip of the module operation.
The operation of the chip MPU total of 11 instructions, can be divided into four broad categories: display function setting command, address setting instructions, data transfer instructions and other type of instruction (such as reading BF).
① Display Function Set instruction includes three display mode: line 5 × 8 dot matrix, two lines of 5 × 8 dot matrix, line 5 × 11 dot matrix format; ② cursor display: do not show, flashing display, lit display; ③ left or right a display control; ④ shift display return after treatment; ⑤ clear the screen. With these instructions, the lcd module can be achieved in a variety of display control.
Address set instruction and data transfer instructions with the conduct, you can achieve MPU and data transfer between RAM. The MPU chip data transfer operation, first send the address set instruction, determine the selection DDRAM or CGRAM data transmission, and the address is written to the counter by setting the number of AC, the AC for RAM addressing operation. The MPU RAM read and write commands sent, can control the display character. MPU BF is an instruction detection, but does not require instruction decoding operations directly in MPU I / O port operation can be completed 3.1 has been introduced, not repeat them here. When the LCD drive control instruction to complete a chip, through the internal circuit generates a high signal BFRESET, the BF is reset, waiting for the next instruction.
LCD controller functions
LCD controller's function is to display drive signal, thereby driving the LCD. Users only need to write a series of registers, to complete the configuration and the display driver. In the process of designing LCD driver first and foremost is to configure the LCD controller and LCD controller in the configuration of the most important step is the frame buffer (FrameBuffer) designation. The user to display the contents are to be read out from the buffer to display on the screen. Frame buffer size is determined by the screen resolution and number of colors displayed decision. Drive frame buffer implementation is the focus of the entire drive the development process. S3C2410 the LCD controller can support two kinds of STN and TFT LCD. For STN LCD flat panel, the LCD controller can support four pairs of scan, 4-bit single scan, and 8-bit single scan three display types, support for 4 and 16 grayscale monochrome display mode, supports 256 colors and 4096 colors display, which can be accessed multiple resolution of the serial oled
display, for example, 640 × 480,320 × 240 and 160 × 160, etc., in the 256-color display mode, maximum support 4096 × 1024,2048 × 2048 and 1024 × 4096 display. TFT LCD flat panel can support 1-2-4-8bpp (bits per pixel) color palette color palette display mode and non-16bpp true color display.
Frame buffer is seen in the Linux 2.2.xx and later kernels which a driver interface, this interface will display device abstraction for the frame buffer device area. The image frame buffer hardware device provides an abstraction process, which represents the number of video hardware, allows the application software through a well-defined interface to access the graphics hardware device. Such software without knowing any thing related to the underlying hardware drivers (such as hardware registers). It allows the upper application in graphics mode to read and write directly to the display buffer and the I / O control and other operations. Through special device nodes can access the device, such as / dev / fb *. Users can use it as an image display memory, be mapped into the process address space, you can read and write operations, and read and write operations can be reflected to the mini lcd module.
Frame buffer device corresponding device file is / dev / fb *. If the system has multiple graphics cards, Linux also supports multiple frame buffer device, up to 32, that is / dev/fb0 ~ / dev/fb31. The / dev / fb then point to the current frame buffer device, under normal circumstances, the default frame buffer device is / dev/fb0.
Frame buffer device also belongs to a character device, using the "file level - driver layer" interface mode.
Frame buffer is seen in the Linux 2.2.xx and later kernels which a driver interface, this interface will display device abstraction for the frame buffer device area. The image frame buffer hardware device provides an abstraction process, which represents the number of video hardware, allows the application software through a well-defined interface to access the graphics hardware device. Such software without knowing any thing related to the underlying hardware drivers (such as hardware registers). It allows the upper application in graphics mode to read and write directly to the display buffer and the I / O control and other operations. Through special device nodes can access the device, such as / dev / fb *. Users can use it as an image display memory, be mapped into the process address space, you can read and write operations, and read and write operations can be reflected to the mini lcd module.
Frame buffer device corresponding device file is / dev / fb *. If the system has multiple graphics cards, Linux also supports multiple frame buffer device, up to 32, that is / dev/fb0 ~ / dev/fb31. The / dev / fb then point to the current frame buffer device, under normal circumstances, the default frame buffer device is / dev/fb0.
Frame buffer device also belongs to a character device, using the "file level - driver layer" interface mode.
2013年8月6日星期二
The type of liquid crystal display
Is called the liquid crystal display made of a liquid crystal display, in English called LCD (Liquid Crystal Display). Its kind of drive can be divided according to static drive (Static), simple matrix drive (SimpleMatrix) and active matrix drive (ActiveMatrix) three. The one simple matrix type is commonly known as passive (Passive), can be divided into a twisted nematic (Twisted Nematic, referred TN) and super twisted nematic (Super Twisted Nematic, referred STN) two kinds; while active matrix type places thin-film transistor type (Thin Film Transistor; TFT) is the current mainstream. TN TN type liquid crystal display technology can be said to be the most basic OLED Module, other types of liquid crystal displays can be said is modeled to be improved TN type. Similarly, its principle of operation is also simple than other techniques. TN The structure includes a vertical direction and the horizontal direction of the polarizer (Polarizer), which lines the groove having a middle mixed crystal material and a conductive glass substrate (Glass).
STN / DSTN STN type display principle is similar, except that a TN-type liquid crystal molecules are rotated 90 degrees to the incident light, the incident light can be rotated and the STN 180 to 270 degrees. TN display itself is only a simple two display brightness (or black and white), can not produce color changes. TN LCD used the "direct drive" can not display more pixels, and the screen contrast is small, slow response, perspective and we only +30 degrees (ie, viewing angle of about 60 degrees), the display quality is poor; it TN type LCD main purpose is to simply display the number of characters and words, such as: electronic watches and electronic calculators. STN improves the appearance of a narrow perspective on the shortcomings and improve the ratio, STN to "multi-task-driven" to increase the number of scan lines to improve pixel display, high quality more than TN. Then with the use of color filters, the color of any pixel of the display matrix (pixel) is divided into three sub-pixels (sub-pixel), respectively, through the color filters red, green, and blue, and then through the three primary colors ratio The harmony, can show full-color mode approximation colors. As STN display screen color contrast is still only reached 30:1 (compare the smaller screen more clear); reaction speed is 150ms (milliseconds), as a general operating display interface is acceptable but still not enough speed to play movies.
Since there are still many shortcomings STN, DSTN subsequent way through the dual-scan display, the DSTN dual scanning technology, so the effect is relatively STN display, it has greatly improved. DSTN response speed of up to 100ms, but they are "passive driven", changing the voltage of the electric field in the process repeated, each pixel recovery process is slow, rapid change in the screen, for example: display the broadcast of the game of tennis , will produce the so-called "tail" phenomenon. Especially when the tennis player hitting the moment, you can see on the screen drag the "ball track tail" phenomenon. However, DSTN cheap, power consumption is low, the number of PDA, etc., are still used as a display device DSTN. TFT TN and STN type liquid crystal displays are using a field voltage driving method, if the display size increase, the central portion of the electrode will lengthen the response time changes, the display speed can not keep up. In order to improve this problem, active matrix (active-matrix) drive is presented, active TFT liquid crystal display structure is more complex include: the backlight tubes, light guide plate, polarizer, filter plate, a glass substrate, with the film, the liquid crystal material and a thin mode transistors, etc. (Figure 3-2). TFT type liquid crystal display device in the conductive glass of fine lines painted on the mesh electrode by a thin film type transistors arranged in a matrix switch in each line intersects with a control gate, control gate of each display point with the drive signals for the move. Electrode of the transistor matrix display signals on or off by the liquid crystal molecules voltage, so that the liquid crystal molecular axis shift from "light" or "dark" contrast of the display to avoid dependence on the electric field effect, turn the transistor on and off in the rate of as the determining step. Therefore, TFT-LCD display quality than the TN / STN good, the screen display of up to 150:1 contrast, 30ms or faster reaction rate approximation. While the effect can be full color or true color display, products for PDA, notebook computers, lcd module, car navigation systems, digital cameras and LCD projectors.
STN / DSTN STN type display principle is similar, except that a TN-type liquid crystal molecules are rotated 90 degrees to the incident light, the incident light can be rotated and the STN 180 to 270 degrees. TN display itself is only a simple two display brightness (or black and white), can not produce color changes. TN LCD used the "direct drive" can not display more pixels, and the screen contrast is small, slow response, perspective and we only +30 degrees (ie, viewing angle of about 60 degrees), the display quality is poor; it TN type LCD main purpose is to simply display the number of characters and words, such as: electronic watches and electronic calculators. STN improves the appearance of a narrow perspective on the shortcomings and improve the ratio, STN to "multi-task-driven" to increase the number of scan lines to improve pixel display, high quality more than TN. Then with the use of color filters, the color of any pixel of the display matrix (pixel) is divided into three sub-pixels (sub-pixel), respectively, through the color filters red, green, and blue, and then through the three primary colors ratio The harmony, can show full-color mode approximation colors. As STN display screen color contrast is still only reached 30:1 (compare the smaller screen more clear); reaction speed is 150ms (milliseconds), as a general operating display interface is acceptable but still not enough speed to play movies.
Since there are still many shortcomings STN, DSTN subsequent way through the dual-scan display, the DSTN dual scanning technology, so the effect is relatively STN display, it has greatly improved. DSTN response speed of up to 100ms, but they are "passive driven", changing the voltage of the electric field in the process repeated, each pixel recovery process is slow, rapid change in the screen, for example: display the broadcast of the game of tennis , will produce the so-called "tail" phenomenon. Especially when the tennis player hitting the moment, you can see on the screen drag the "ball track tail" phenomenon. However, DSTN cheap, power consumption is low, the number of PDA, etc., are still used as a display device DSTN. TFT TN and STN type liquid crystal displays are using a field voltage driving method, if the display size increase, the central portion of the electrode will lengthen the response time changes, the display speed can not keep up. In order to improve this problem, active matrix (active-matrix) drive is presented, active TFT liquid crystal display structure is more complex include: the backlight tubes, light guide plate, polarizer, filter plate, a glass substrate, with the film, the liquid crystal material and a thin mode transistors, etc. (Figure 3-2). TFT type liquid crystal display device in the conductive glass of fine lines painted on the mesh electrode by a thin film type transistors arranged in a matrix switch in each line intersects with a control gate, control gate of each display point with the drive signals for the move. Electrode of the transistor matrix display signals on or off by the liquid crystal molecules voltage, so that the liquid crystal molecular axis shift from "light" or "dark" contrast of the display to avoid dependence on the electric field effect, turn the transistor on and off in the rate of as the determining step. Therefore, TFT-LCD display quality than the TN / STN good, the screen display of up to 150:1 contrast, 30ms or faster reaction rate approximation. While the effect can be full color or true color display, products for PDA, notebook computers, lcd module, car navigation systems, digital cameras and LCD projectors.
LCD universal basis
The era of ultra-thin flat panel display
Used in television CRT (cathode ray tube) has a large volume and weight, size constraints and other shortcomings. With the development of electronic technology, the requirement for more and more mobile display, CRT's inherent limitations, allowed miniaturization, mobility ideal hindered. This makes developing a new generation of display technology becomes more is necessary! A new generation of display emphasizes several points: plane at right angles, the screen display is not deformed, light, small energy consumption, easy to carry and at the same video signal with the existing technical compatibility. Currently it comes to ultra-thin display technology, the most popular application when it is Character LCD Modules, and covered the digital cameras, notebook computers, PDA, etc., need to display complex information in electronic products altogether without it. TFT LCD technology but also contains, low-temperature polycrystalline silicon TFT LCD, reflective TFT Lcd Modules, etc., a number of different display technologies
Describes the physical properties of the liquid crystal, it must first understand a direction generally a crystalline solid, and the liquid crystal material of this particular, not only the direction of a general crystalline solid, but also has the mobility of the liquid. Solid crystals must be rotated to change the direction of the entire crystal, changing the liquid crystal NA would not bother, it's directionality can be controlled by electric or magnetic fields.
Changing the direction of the liquid crystal composition as the liquid crystal are different from the conventional liquid crystal and the electric field parallel to the low potential, so that when the applied electric field toward the direction of rotation when the relative, but also a liquid crystal is perpendicular to the electric potential than the corresponding low. Since the liquid crystal to the applied force (electric or magnetic field sensitive), which presents a directional effect, but also led to the incident when the light when the LCD, liquid crystal molecules are bound to the arrangement in accordance with the road, resulting in a natural deflection is like.
Part of the electronic structure of the liquid crystal molecules, there is a strong electron conjugated athletic ability, so when the liquid crystal molecules by the applied electric field, the polarization can easily be induced dipole (induced dipolar), which is the liquid crystal molecules interaction between a source of strength. The general electronic products in a liquid crystal display, that is the use of a liquid crystal electro-optical effect, with an external voltage control, and through the refractive properties of the liquid crystal molecules, and the rotation ability of light to obtain bright and dark conditions, and then to imaging purposes.
Used in television CRT (cathode ray tube) has a large volume and weight, size constraints and other shortcomings. With the development of electronic technology, the requirement for more and more mobile display, CRT's inherent limitations, allowed miniaturization, mobility ideal hindered. This makes developing a new generation of display technology becomes more is necessary! A new generation of display emphasizes several points: plane at right angles, the screen display is not deformed, light, small energy consumption, easy to carry and at the same video signal with the existing technical compatibility. Currently it comes to ultra-thin display technology, the most popular application when it is Character LCD Modules, and covered the digital cameras, notebook computers, PDA, etc., need to display complex information in electronic products altogether without it. TFT LCD technology but also contains, low-temperature polycrystalline silicon TFT LCD, reflective TFT Lcd Modules, etc., a number of different display technologies
Describes the physical properties of the liquid crystal, it must first understand a direction generally a crystalline solid, and the liquid crystal material of this particular, not only the direction of a general crystalline solid, but also has the mobility of the liquid. Solid crystals must be rotated to change the direction of the entire crystal, changing the liquid crystal NA would not bother, it's directionality can be controlled by electric or magnetic fields.
Changing the direction of the liquid crystal composition as the liquid crystal are different from the conventional liquid crystal and the electric field parallel to the low potential, so that when the applied electric field toward the direction of rotation when the relative, but also a liquid crystal is perpendicular to the electric potential than the corresponding low. Since the liquid crystal to the applied force (electric or magnetic field sensitive), which presents a directional effect, but also led to the incident when the light when the LCD, liquid crystal molecules are bound to the arrangement in accordance with the road, resulting in a natural deflection is like.
Part of the electronic structure of the liquid crystal molecules, there is a strong electron conjugated athletic ability, so when the liquid crystal molecules by the applied electric field, the polarization can easily be induced dipole (induced dipolar), which is the liquid crystal molecules interaction between a source of strength. The general electronic products in a liquid crystal display, that is the use of a liquid crystal electro-optical effect, with an external voltage control, and through the refractive properties of the liquid crystal molecules, and the rotation ability of light to obtain bright and dark conditions, and then to imaging purposes.
2013年8月5日星期一
LCD viewing angle
LCD viewing angle really is a vexing problem when the backlight through the polarizing film, and orientation of the liquid crystal layer, the light output will have a direction. That most of the light is emitted from the screen vertically, so from a certain point of view a larger LCD monitor, we can not see the original color, or even only to see all white or all black. To solve this problem, manufacturers have also started to develop wide-angle technology, so far there are three of the more popular technology, namely: TN + FILM, IPS (IN-PLANE-SWITCHING) and MVA (MULTI-DOMAIN VERTICAL alignMENT).
First TN + FILM technology, which is based on the original, an additional layer of wide viewing angle compensation film. This layer of the viewing angle compensation film can be increased to 150 degrees, is a simple way, in a large number of applications in liquid crystal displays. However, this technique does not improve the contrast ratio and response time performance, perhaps for manufacturers, TN + FILM is not the best solution, but it really is the cheapest solution, so most of the Taiwan companies are using this Methods to build 15-inch LCD monitor.
IPS (IN-PLANE-SWITCHING, in-plane switching) technology, which claims to allow greater vertical and horizontal viewing angle of 170 degrees. There are advantages, there will be shortcomings, IPS technology, while increasing the viewing angle, but with two electrodes driving the liquid crystal molecules, need to consume more power, which makes the LCD monitor's power consumption increases. Furthermore deadly is driven in this way the response time of the liquid crystal molecules will be relatively slow.
MVA (MULTI-DOMAIN VERTICAL alignMENT, multi-domain vertical alignment) technology, the principle is to increase the prominence to form a plurality of viewable area. When the liquid crystal molecules is not completely in a static vertically, the applied voltage to the liquid crystal molecules are arranged horizontally, so that the light can be through the layers. MVA technology will increase the viewing angle to 160 degrees or more, and provide more than IPS and TN + FILM shorter response time. This technology is developed by Fujitsu, Taiwan Chi Mei (CMO in mainland China is a subsidiary of CMV) and Taiwan's AU Optronics authorized to use this technology. In addition to the above three wide viewing angle technology, there is the father of the lcd module SHARP exclusive ASV technology, a variant of Korea SAMSUNG MVA technology "PVA", as well as South Korea's Hyundai (HYDIS) of IPS deformation "FFS" technology.
Visual range is divided into parallel visual range and vertical viewing range, horizontal viewing range of the vertical axis is the Low Temperature Display as the center, left and right, you can clearly see the range of the image. Vertical viewing range is parallel to the axis of the display as the center, moving up and down, you can clearly see the range of the image. Viewing angle to the "degree" as a unit, the current form of the more commonly used label marked total direct horizontal, vertical range, such as: 150/120 degrees viewing angle of the current minimum of 120/100 degrees (horizontal / vertical), below this value will not be accepted, preferably 150/120 degrees.
First TN + FILM technology, which is based on the original, an additional layer of wide viewing angle compensation film. This layer of the viewing angle compensation film can be increased to 150 degrees, is a simple way, in a large number of applications in liquid crystal displays. However, this technique does not improve the contrast ratio and response time performance, perhaps for manufacturers, TN + FILM is not the best solution, but it really is the cheapest solution, so most of the Taiwan companies are using this Methods to build 15-inch LCD monitor.
IPS (IN-PLANE-SWITCHING, in-plane switching) technology, which claims to allow greater vertical and horizontal viewing angle of 170 degrees. There are advantages, there will be shortcomings, IPS technology, while increasing the viewing angle, but with two electrodes driving the liquid crystal molecules, need to consume more power, which makes the LCD monitor's power consumption increases. Furthermore deadly is driven in this way the response time of the liquid crystal molecules will be relatively slow.
MVA (MULTI-DOMAIN VERTICAL alignMENT, multi-domain vertical alignment) technology, the principle is to increase the prominence to form a plurality of viewable area. When the liquid crystal molecules is not completely in a static vertically, the applied voltage to the liquid crystal molecules are arranged horizontally, so that the light can be through the layers. MVA technology will increase the viewing angle to 160 degrees or more, and provide more than IPS and TN + FILM shorter response time. This technology is developed by Fujitsu, Taiwan Chi Mei (CMO in mainland China is a subsidiary of CMV) and Taiwan's AU Optronics authorized to use this technology. In addition to the above three wide viewing angle technology, there is the father of the lcd module SHARP exclusive ASV technology, a variant of Korea SAMSUNG MVA technology "PVA", as well as South Korea's Hyundai (HYDIS) of IPS deformation "FFS" technology.
Visual range is divided into parallel visual range and vertical viewing range, horizontal viewing range of the vertical axis is the Low Temperature Display as the center, left and right, you can clearly see the range of the image. Vertical viewing range is parallel to the axis of the display as the center, moving up and down, you can clearly see the range of the image. Viewing angle to the "degree" as a unit, the current form of the more commonly used label marked total direct horizontal, vertical range, such as: 150/120 degrees viewing angle of the current minimum of 120/100 degrees (horizontal / vertical), below this value will not be accepted, preferably 150/120 degrees.
What is the judge's standard LCD monitor
Judgment standard LCD monitor following main points:
(1) resolution. Resolution refers to the screen each row and column number of pixels, LCD and CRT display resolution different, generally can not be adjusted, which is set by the manufacturer and regulations. Now lcd module resolution is usually 800 points × 600 lines SVGA display mode and 1024 × 768 XGA line display mode.
(2) refresh rate. Refresh rate refers to the display frame rate, ie, the frequencies of each pixel refresh time, it and the screen scanning speed and the ability to avoid screen flicker closely related. If the refresh rate is too low, the screen image may appear flicker or jitter.
(3) viewing angle. Viewing angle is standing on the center line of the screen up and down, left and right can still clearly see a certain position of the screen image angle range. In general, LCD viewing angles are symmetrical, but may not necessarily up and down, often up and down angle of less than about angles. Of course, viewing angle is the bigger the better. LCD TV viewing angle can be up and down, left and right 160 degree range, can achieve good television ratings.
(4) Brightness, contrast. Brightness is the maximum brightness of the liquid crystal television many nits per square meter (cd/m2), Contrast is the ratio of the light and dark. Currently the maximum brightness of the TFT Lcd Modules TV 450cd/m2, contrast ratio of 500:1.
(5) response time. Response time response of each pixel of the liquid crystal display response speed of the input signal, that is, from dark to light or light dimmer speed. The smaller the response time does not occur when watching motion picture film tail dragging feeling.
(1) resolution. Resolution refers to the screen each row and column number of pixels, LCD and CRT display resolution different, generally can not be adjusted, which is set by the manufacturer and regulations. Now lcd module resolution is usually 800 points × 600 lines SVGA display mode and 1024 × 768 XGA line display mode.
(2) refresh rate. Refresh rate refers to the display frame rate, ie, the frequencies of each pixel refresh time, it and the screen scanning speed and the ability to avoid screen flicker closely related. If the refresh rate is too low, the screen image may appear flicker or jitter.
(3) viewing angle. Viewing angle is standing on the center line of the screen up and down, left and right can still clearly see a certain position of the screen image angle range. In general, LCD viewing angles are symmetrical, but may not necessarily up and down, often up and down angle of less than about angles. Of course, viewing angle is the bigger the better. LCD TV viewing angle can be up and down, left and right 160 degree range, can achieve good television ratings.
(4) Brightness, contrast. Brightness is the maximum brightness of the liquid crystal television many nits per square meter (cd/m2), Contrast is the ratio of the light and dark. Currently the maximum brightness of the TFT Lcd Modules TV 450cd/m2, contrast ratio of 500:1.
(5) response time. Response time response of each pixel of the liquid crystal display response speed of the input signal, that is, from dark to light or light dimmer speed. The smaller the response time does not occur when watching motion picture film tail dragging feeling.
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