Luxurious, elegant, and high-class! How much is this screen? ? ?

【Haichuan Equipment Guessing Game】Why is the design unconventional? ? ? https://bbs.hcbbs.com/thread-4912410-1-1.html (Source: Haichuan Chemical Industry Forum Website)

Hengli Petrochemical still has considerable strength

Actually, it’s not that expensive; around one million. The control room is so large; the screens are rather small. But a large screen isn’t of much use; it’s all for the managers to view, and the operators are exposed to blue light radiation. Large screens are not ergonomic

Compared to millions spent on large screens and millions spent on engineering work, it’s still worth it

【Haichuan Equipment Guessing Game】Which factory has so many tea makers? ? ? https://bbs.hcbbs.com/thread-4944745-1-1.html (Source: Haichuan Chemical Industry Forum Website)

The price of this type has dropped; it’s a color LED display panel. For those with high resolution, the industry uses terms like ‘P’ to refer to the size of each pixel – the smaller the pixels, the higher the price. A regular display panel costs just a few dozen dollars；

Ten years ago it cost a million; now the cost is lower – 700,000 to 800,000 should be enough

I bought some of this company’s stocks, and I’m currently losing money on them. . . . . . I wonder when he’ll become powerful.

This post was last edited by *nht1 on 2023-9-16 at 22:32. There are two options: either use 96 panels (16×6) to create a seamless 55-inch LCD screen, or use 84 panels (14×6); another option is to use a single large LED screen. The clarity of a screen made up of LCD panels is much higher. Actually, it’s all pointless – the content that can be displayed on a 42-inch TV can be shown on a much larger screen as well; it’s the same thing. In some cases, such screens are even used for displaying surveillance footage, which is utterly absurd. To put it simply, it’s just done to give an illusion of grandeur. Blue light radiation can be quite harmful to the brain. Let me explain this to you: blue light radiation originates from LED chips. An LED screen is actually composed of countless LED lights, which work together to create different color patterns and thus display images. During the display process, these small light sources play a key role. An LED light is made up of a mainstream LED blue light chip and LED phosphor, which together produce light; this assembly is then encapsulated in epoxy resin, with gold wires used to connect the various components. The principle of light emission in LED chips: The mechanism behind the light emission of LED blue light chips involves a PN junction semiconductor; when a voltage is applied across its ends, electrons move between holes and undergo energy level transitions to an excited state, after which they return to the ground state, releasing photons. The photons emitted are primarily blue light, characterized by a short wavelength and high energy. This phenomenon is classified as electroluminescence. The principle of light emission in LED chips: The lighting of LED chips relies primarily on the blue light generated when the LED blue light chip is powered. The peak wavelength of the GaN chip is λp=465nm, with a half-width at half maximum of wd=30nm. The blue light generated is then directed at the LED phosphors coated on the chip, causing these phosphors to be excited and transition from their ground state to higher energy levels; upon returning to the ground state, photons are emitted in this process. This is a form of photoluminescence. In the simplest configuration, a GaN chip is combined with yellow phosphors – the yellow phosphors emit yellow light while the chip emits blue light, and when these two colors combine, white light is produced. Spectrally speaking, this is actually a physical mixture of the two types of light, resulting in an artificial white light, rather than the true white light from natural sunlight. Additionally, if the ratio of the two colors isn’t optimal, some blue light may remain, which is what is referred to as blue light radiation. It’s quite difficult to achieve an ideal situation in practice. Since LED phosphors, in the form of solid powders, are used to emit light on the LED chip, it’s hard to ensure uniformity at all times; therefore, the presence of residual blue light is an inevitable consequence of technical limitations. As such, when choosing a reading lamp for children, it’s advisable to opt for tungsten lamps or fluorescent lamps. Of course, it’s possible that some manufacturers produce panels that can effectively scatter a portion of the blue light. In addition to blue chips combined with yellow yttrium aluminum garnet to produce white light, LED combinations can also use blue chips together with red nitrides and yellow yttrium aluminum garnet to generate white light, or ultraviolet chips combined with red nitrides (R), green cerium (G), and blue tungstomolybdate (B) to produce white light. Personal opinions are for academic exchange only. *Basic knowledge organized by NHT (1) λp (peak wavelength): the wavelength at which the spectral luminous intensity or radiant power is at its maximum. It is a pure physical quantity, generally used for the detection of monochromatic light with a symmetric waveform. (2) λd (principal wavelength): The wavelength corresponding to the color of the main light emitted by the light source, which is visible to the eye, is the principal wavelength ； In the CIE1931 horseshoe coordinates, it is the wavelength corresponding to the point where the line extended from point E (0.33, 0.33) intersects the horseshoe curve with the tested object. Generally, a beam of light that you see is not light of a single wavelength; it is composed of light of many different wavelengths. Among them, if the energy of light of a certain wavelength is greater than that of light of other wavelengths, then this wavelength is the peak wavelength λp of that beam of light. However, the wavelength distribution of the light of various wavelengths in this beam is not necessarily symmetrically distributed around λp. What our eyes perceive is the combined effect of all these wavelengths, and it appears as if it corresponds to light of a single wavelength, and this wavelength value is λd. On the wavelength distribution curve, a vertical line drawn from the abscissa to the curve divides the area under the curve into two equal parts; the wavelength value corresponding to this vertical line is λd. For colored light, we generally look at the λd value, as it can reflect its color more accurately ； The λp value should be used more often when blue light is used to excite phosphors to produce white light, in order to determine whether the λp value of the blue light chip matches the excitation wavelength of the phosphor Additionally, for non-monochromatic light (polychromatic light), which is usually white light, the λd value can only serve as a reference; to determine its color, one still needs to look at its color coordinates or color temperature. The half width of a line spectrum, also known as the half-width at half maximum of a spectral line, refers to the wavelength difference between the positions of the two half-peaks, that is, the half spectral width. (3) Concept of PN junction: N-type semiconductor (N stands for Negative; it is named so because electrons carry a negative charge): In a silicon crystal (or germanium crystal) to which a small amount of the impurity element phosphorus (or antimony) has been added, the semiconductor atoms (such as silicon atoms) are replaced by impurity atoms. Of the five outer electrons of a phosphorus atom, four form covalent bonds with surrounding semiconductor atoms, while the remaining electron is not much bound and can easily become a free electron. Thus, an N-type semiconductor becomes a semiconductor with a high electron concentration, and its electrical conductivity is primarily due to the conduction of free electrons. P-type semiconductor (P stands for Positive; it is named so because holes carry a positive charge): In silicon crystals (or germanium crystals) to which a small amount of the impurity element boron (or indium) has been added, the semiconductor atoms (such as silicon atoms) are replaced by impurity atoms. When the three outer electrons of the boron atom form covalent bonds with the surrounding semiconductor atoms, a \"hole\" is created. This hole can attract bound electrons to \"fill\" it, causing the boron atom to become a negatively charged ion. In this way, such semiconductors become conductive materials because they contain a high concentration of \"holes\" (\"equivalent to\" positive charges). (4) The concept of doping: In nature, almost no ideal crystals without any defects exist, and this is true as well for semiconductor crystals. Regardless of the semiconductor material, defects such as dislocations and impurity atoms are inevitably present within it. The presence of these defects disrupts the periodic potential field generated by the crystal atoms arranged in a strict periodic pattern, thereby introducing new electron energy levels in the semiconductor, which will significantly affect properties such as its electrical conductivity. Since the type and distribution of dislocations are difficult to control, it is hard to precisely regulate their impact on the electrical conductivity of semiconductors; therefore, it is generally desirable for the dislocation density within semiconductor crystals to be as low as possible. Impurity atoms, on the other hand, are different; the type, concentration, and distribution of impurities can all be controlled through appropriate methods during the fabrication of semiconductor crystals, thereby allowing for more precise control over the electrical conductivity of the semiconductors. Therefore, in practical engineering applications, doping is often used to obtain semiconductor materials with desired properties. Doping is a process of intentionally introducing impurities to control the properties of semiconductors. The doping impurities are generally substitutional dopants, that is, the impurity atoms replace the original atoms at the lattice sites. The impurity atoms introduced usually have an atomic structure different from that of the original semiconductor atoms, especially in terms of their valence electron structure; however, the valence electron structures of these two types of atoms are generally similar. For example, impurity atoms from groups III and V correspond to group VI element semiconductors such as Si and Ge, while impurity atoms from groups II and VI correspond to III-V compound semiconductors. (5) LED gold wire: The gold wire is one of the key components in the packaging process of LED chips, and it also plays a decisive role in the lifespan of these LEDs. The purity of the gold wire used to encapsulate LED chips is over 99.99%; this gold is produced through a drawing process. In addition to 99.99% gold, it also contains less than 1% of other trace elements such as Ag/Cu/Si/Ca/Mg, etc. Silver wire is sometimes also used in welding; it is composed of silver with a purity of 99.99% or higher, along with less than 1% of other trace elements such as Ag/Cu/Si/Ca/Mg, etc. Special gold wires for LEDs are drawn from materials with a gold purity of over 99.99%. Through the use of an appropriately designed alloy ratio, these gold wires possess high tensile strength and bonding strength, good balling properties, and a low rate of fracture due to vibration. The bonding wires should mostly be high-purity wires with a purity of 99.99% or higher, with the total amount of trace elements (such as Ag/Cu/Si/Ca/Mg, etc.) kept below 0.01% in order to maintain the properties of gold. There is a difference in diameter between gold wires designed for LEDs and those that are of inferior quality. With 1 gram of gold, it is possible to produce gold wires with a length of 26.37 meters and a diameter of 50μm (2 mils), or wires with a length of 105.49 meters and a diameter of 25μm (1 mil). If the length of the drawn gold wire remains constant and the diameter of the incoming gold wire is half of the original, then the resistance measured for the drawn gold wire will be one quarter of the normal value. For gold wire suppliers, the finer the diameter of the gold wire, the lower the cost and the higher the profit. For LED customers that use gold wires, using gold wires of reduced diameter in order to cut costs can lead to an increase in the resistance of those wires and a decrease in their fusing current, which in turn **reduces the lifespan of the LED light source. The lifespan of a gold wire with a thickness of 1.0 mil is inevitably shorter than that of one with a thickness of 1.2 mil; however, simple tests carried out by packaging factories cannot detect this difference, and precise instruments are required to measure the diameter of the gold wire. Gold wires are highly favored by packaging manufacturers due to their advantages such as high electrical conductivity, good thermal conductivity, corrosion resistance, toughness, and excellent chemical stability. However, their high cost leads to elevated packaging expenses. In the periodic table, among the transition metal elements, gold, silver, copper, and aluminum are the four metals with high electrical conductivity. Many LED manufacturers are trying to develop materials such as copper alloys, gold-plated silver alloy wires, and silver alloy wires as alternatives to the expensive gold wires. Although these alternatives are superior to gold wires in certain aspects, they are much less stable chemically; for example, silver wires and gold-plated silver alloys are prone to corrosion by sulfur/chlorine/bromine, while copper wires tend to oxidize. In the case of encapsulating silicone similar to water-absorbing and breathable sponges, these alternatives make the bonding wires susceptible to chemical corrosion, reducing the reliability of the light source; over time, the LED chips are prone to wire breaks and failure.