Door led display features

Time:2019-01-07 Views:33

Like many technical terms used in applications, there is no generally accepted and strict definition of LED graphics and text displays.

The graph mentioned here refers to any graph composed of a single brightness line, so as to distinguish it from the image composed of different brightness (grayscale) dot matrix.The main feature of picture and text display screen is that it only controls the on and off (light or off) of LED LED dot matrix and does not control the light intensity of LED. The color of LED device can be monochrome, two-color or even multi-color.

LED by the appearance of the display screen can be made into a bar, called a bar graphic display (screen) : can be made by a certain height proportion of rectangular planar graphic display. Actually, the screen is just a width greater than the height of the graphic display, on the principle of display and control, there is no difference. Both the graphics and text, is control with these graphics or text corresponding to the location in which the various points of light LED device.Usually, the graphic text to be displayed is converted into dot matrix graphics in advance, and the data is displayed in a certain format according to the requirements of display control.

When the LED device is required to emit light, the corresponding bit 1 in the data is filled.Otherwise you put a 0.Of course. According to the arrangement of the control circuit, the opposite definition is also feasible. In this way, according to the graphics and text to be displayed, the display data can be filled in point by point in each column of the display screen.A data file that displays graphics. Its format is relatively free, as long as it meets the requirements of display control.

The dot matrix format of the characters is quite standard, and it can use the current computer font.For example, Chinese characters have song style, song style, regular, black and other options.The size can be 16x16.24x24.32x32.48x48 and other different specifications. Figure 6-5 shows the 16x16 lattice structure of the Chinese character "welcome" and the display data arranged from top to bottom by row and from left to right by column for each row.Display data is represented in bytes in a 16-byte format.

It is very flexible and can be combined and changed as needed. As long as the appropriate data files are designed, satisfactory display effect can be achieved.Therefore, it is very effective to use a dot matrix graphic display screen to display information that often needs to be changed.

Bars are often used for short, clear messages. For example, they show bus Numbers and flight information from stations and airports, or welcome messages from shopping malls, or short notices from office buildings.Flat screen is used to display more complex information, such as the arrival and departure time of multiple trains in the station, flight operation status in the airport and stock prices in the stock exchange.The advantage of lattice display is that it ADAPTS to the change of information at the cost of the price of lattice display and its complicated control.

Dot matrix display all position in the whole display unit with LED device. As one type of digital tube LED display device to shine only seven segment (eight) position in the LED device. Other location is blank. Therefore, dot matrix display under the condition of the same area, its price is more expensive than to digital tube display.On the other hand, because the digital tube can display limited information, only 0-9(and then extended to a-f) A few characters, the control of these characters is achieved by combining the luminescence of 7 LED.

Dot matrix displays are not. They control all the leds on the dot matrix and generate all the possible graphics and text. Their display data and control circuits are naturally much more complex.In other words, it is not required to display arbitrarily changing information.In this case, not necessarily non-lattice display.

For example, on the display screen of stock quotation information of a stock exchange, the main contents can be divided into two parts: one is the name of the stock and the other is the quotation.In this case, the mixed use of digital tube and lattice display unit on a screen, this screen can be called mixed screen.

, under the same condition, hybrid screen is lower than the cost of a lattice screen. There is also a situation, although the display graphics or text is more complex, but do not need to change. When can the LED directly to the lamp according to the display of the graphic layout on the PCB. All LED lamp control together, either all light. Either all out, natural very single control circuit.

The most common color is monochrome graphic screen. Monochrome screen mostly USES red, orange and orange LED dot matrix units.For a two-color graphic screen and a multi-color graphic screen, each "dot" in the LED lattice is arranged with two or more different colored LED light emitting devices.

In other words, each color has its own display matrix.Display, each color display lattice is public control.The desired effect can be achieved by designing the display data of various colors in advance and sending them to the respective display lattice when displaying.

In order to attract the audience and enhance the display effect, there are various display modes. The simplest display mode is static display.The "static display mode" mentioned here is different from the static drive mode, which means that the effect of the circle text displayed by subjective observation is static.In the static display can use scanning drive mode.Corresponding to the static display mode, there are a variety of dynamic display mode, they are able to display the graphics and text movement.

According to the movement characteristics of graphic, and can be divided into flashing, translation, rotation, scaling, and other display mode. Different display mode, the method of main is constantly refresh control data over time. In order to make the graphic movement, to refresh the display data. It doesn‘t mean have to display the data to write. Can be achieved by a certain algorithm generated directly from the original data.

For example, if the row number is adjusted in order, the display image and text can be shifted up and down; if the column position is adjusted in order, the left and right translation can be achieved: if the row and column order are adjusted at the same time, the diagonal translation can be achieved.

When the algorithm of the door head LED display is too complex and time-consuming, it can also be considered to generate the refresh data in advance and store for later use.The refresh is too slow. The dynamic is not obvious: the refresh is too fast, the middle process can‘t be seen clearly.Generally, the refresh cycle can be controlled in the range of a few milliseconds to a few tens of milliseconds.