Planar gratings are mainly used for spectrum analysis and light wavelength measurement. It is an optical device composed of a large number of parallel slits of equal width and equal distance. There are many types of gratings. The commonly used grating is made by engraving a large number of parallel notches on the glass. The nicks are divided into opaque parts, and the smooth part between the two nicks can transmit light. The exquisite grating produced by our company has thousands to tens of thousands of nicks within 1CM width, and the light passes through the grating. The resulting spectrum is the result of single-slit diffraction and multi-slit interference. Plane Diffraction Grating,Reflective Grating,Light Grating,Optical Grating Changchun Realpoo Photoelectric Co., Ltd. , https://www.optics-realpoo.com
LED segment displays are devices that are packaged together by a plurality of light-emitting diodes to form an "8" shape. The leads are connected internally, and only need to draw their respective strokes and common electrodes. The number of commonly used segments of the led digital tube is generally 7 points plus one decimal point, and the other is similar to the 3-digit "+1" type. There are bits in the digits, 1, 2, 3, 4, 5, 6, 8, 10, etc.., led digital tube is divided into two categories according to the different methods of LED connection, to understand the LED These features are important for programming because different types of digital tubes have different programming methods than their hardware circuits. Figure 2 shows the internal circuits of the common cathode and common anode digital tubes. Their principle of illumination is the same, except that their power supply polarity is different. The colors are red, green, blue, yellow and so on. Led digital tube is widely used in instruments, clocks, stations, home appliances and other occasions. Pay attention to product size, power consumption, brightness, wavelength, etc. when selecting.
Each stroke is corresponding to a letter indicating that DP is a decimal point.
LED digital tube should be displayed normally, it is necessary to use the drive circuit to drive the various segments of the digital tube, thus showing the number we want, so according to the different driving methods of the LED digital tube, it can be divided into two types: static and dynamic. .
A, static display driver:
Static drives are also called DC drives. Static drive means that each segment of each digital tube is driven by an I/O port of a single-chip microcomputer, or by using a BCD code two-tenth* device*. The advantage of static drive is that the programming is simple, the display brightness is high, and the disadvantage is that it takes up more I/O. For example, if you drive 5 digital tube static display, you need 5×8=40 I/OåŸ to drive, you need to know that a 89S51 MCU is available. The I/O is only 32. Therefore, the actual driver must increase the * drive to drive, increasing the complexity of the hardware circuit.
B, dynamic display driver:
The digital tube dynamic display interface is one of the most widely used display modes in the single-chip microcomputer. The dynamic drive is to display the same names of the eight display strokes of all digital tubes "a, b, c, d, e, f, g, dp". The terminals are connected together, and the bit gate control circuit is additionally added for the common pole COM of each digital tube. The bit gates are controlled by independent I/O lines. When the single chip outputs the font code, all the digital tubes are received. The same glyph code, but the digital tube will display the glyph, depending on the control of the microcontroller's semaphore COM terminal circuit, so we only need to open the gating control of the digital tube that needs to be displayed, the bit will display Out of the glyph, there will be no bright digital tube without strobing.
By controlling the COM end of each LED digital tube by means of time-sharing, the digital tubes are controlled to display in turn, which is dynamic driving. In the process of rotating display, the lighting time of each bit digital tube is 1~2ms. Due to the persistence of human vision and the afterglow effect of the LED, although the digital tubes are not lit at the same time, they only need to be scanned. The speed is fast enough, giving the impression that a stable set of display data, no flickering, dynamic display and static display are the same, can save a lot of I / O åŸ , and lower power consumption.