CD disks are highly used in multimedia applications. CD cases, CD cleaning brushes, CD cleaning machines and CD drive cleaning disks can be used to use and maintain CDs for us.

The life of the optical disc depends on three factors:

1. The physical and chemical characteristics of the optical disc itself. The optical disc is composed of a polymer plastic (polycarbonate) layer, an aluminum film layer and a protective coating. Partially composed. If the ambient temperature is too high or too low, it will accelerate the aging of the plastic, and the aluminum film will be slowly oxidized in contact with the air. In addition, the data on the optical disc is read-only and cannot be rewritten. Once damaged, it cannot be repaired or marked and can only be discarded, which is very different from the disk.

2. Daily maintenance. Optical discs are highly used in multimedia applications. Improper use and incorrect maintenance methods will shorten the life of optical discs. CD boxes, CD cleaning brushes, CD cleaning machines and CD drive cleaning disks bring great convenience to us in using and maintaining CDs.

3. The upgrading of computer technology. Today, with the rapid development and rapid changes in the computer industry, the day a technology matures is when its decline is approaching. CDs are no exception. Which of the most popular software in the past few years has not been updated to the latest version? There are a few games on the 180-in-1 CD that are still being played! What is even more chilling is that the optical drive spins faster and faster, and the "eyesight" is getting worse and worse. Many disks that could be read before are now unrecognizable, forcing everyone to find the method of "put a good disk first and wait for it to stabilize." The "trick" of replacing a bad disk. Therefore, the idea that optical disks can last for hundreds of years is just wishful thinking. The actual service life of an optical disc can reach 10 years, which is considered a "longevity".

Misunderstanding 2: The longer the disc is used in the optical drive, the easier it is to damage the disc.

When used, it rotates at high speed, and the optical head in the optical drive emits a laser beam that shines on the optical disc. The change in intensity of the reflected beam detects the data. During this process, the optical head does not come into direct contact with the disc and will not damage the disc. However, a disc with excessive dirt and excessive deformation will cause the laser beam to be poorly focused, affect the positioning accuracy of the optical head, and in severe cases may cause mechanical damage to the optical head.

Misunderstanding 3: As long as the plastic surface is protected, the normal use of the disc can be ensured

The standard CD-ROM disc has a diameter of 120 mm, a center mounting hole of 15 mm, and a thickness of It is 1.2 mm and weighs about 14~18 grams. (There are also optical discs with a disc diameter smaller than 120 mm, but the thickness is still the same.)

The radial cross section of a CD-ROM disc has three layers:

(1) Polymer Transparent substrate made of polycarbonate;

(2) Aluminum reflective/data recording layer;

(3) Printing paint protective layer.

The laser beam must be incident on the plastic surface of the substrate to reach the pits, and then be reflected to read the data. Scratches, fingerprints and dust on the plastic surface can affect data reading. But the data is actually stored on the aluminum film. The protective coating is so thin that a slight friction can destroy it and cause fatal damage to the aluminum film, while scratches on the plastic surface can usually be compensated for by error correction. Strictly speaking, the aluminum film layer and protective coating are more important than the plastic layer and need to be carefully protected.

By the way, never put labels on protective coatings. The convenience is temporary. When the label loses its stickiness and becomes warped, the aluminum film will stick up and the beloved data on the disc will be taken away at the same time. In addition, after the protective film is attached to the disc, there is still a certain gap between it and the disc. The air moisture can easily penetrate into the gaps, but it is not easy to evaporate out (especially in spring). Over time, it will cause the disc to become moldy or attract microorganisms to chew on the protective layer of the disc. Therefore, I suggest that you try not to use protective films and be more careful when using discs. If you must use it, please store the disc with a protective film in a dry environment.

Myth 4: The outer edge of the optical disc is the most important area, where a lot of important information is stored

The data storage method of optical discs is different from that of floppy disks. The most important thing about a floppy disk is the 0 and 1 tracks on its outer edge, but the data on the optical disk is recorded in a spiral sequence from the inside to the outside. Experienced friends may know that scratches near the outer edge of the disc may only prevent a few images from being displayed normally, while scratches on the file table at the beginning of data on the inner edge will "shoot" the entire disc.

Misunderstanding 5: It doesn’t matter if there is some dust or dirt on the disc. As long as it does not affect the reading of the disc, you can continue to use it.

When you find dust or dirt on the disc, you should use a clean flannel in time. , silk or suede rub. Otherwise, these dust and dirt will contaminate and adhere to the optical head, affecting data reading. Two points must be paid attention to when wiping: first, the action should be gentle to avoid bringing new scratches to the disc, and those stubborn dirt should be cleaned; second, the wiping should be done radially from the inside to the outside, so that the wiper can Try to minimize damage to the disc.

Misunderstanding 6: You can use paper and alcohol to wipe off stubborn dirt on the CD

Paper is too hard for the CD. Using it to wipe the CD will cause more scratches than stubborn dirt. Dirt is more difficult to remove. Organic solvents such as alcohol will react with polymeric plastics, blurring the surface of the plastic layer, causing the laser beam to be unable to focus, and may even penetrate into the plastic layer, exposing the aluminum film to the air, causing corrosion of the aluminum film, and completely destroying the data on the disc. .

The correct way to remove stubborn dirt is: use medical absorbent cotton dipped in a small amount of clean water (preferably distilled water), and wipe the dirty area repeatedly in the radial direction. Do not use too much force. For oil stains, use cotton wool dipped in a small amount of neutral detergent. Wipe method Same as above, then use dry cotton wool to dry the disk surface, and finally put it in a cool place to dry. Be careful not to leave water droplets after cleaning, otherwise patterns will appear on the disk after drying, and do not expose it to the sun to prevent the disk from being deformed by heat.

Why can’t my CD be read for no reason because it has neither scratches nor holes?

This is the result of oxidation, actinization or deformation of the optical disc. The reason for oxidation is: moisture intrudes from the interlayer between the outer surface and the inner ring of the optical disc, causing the recording layer to be oxidized. Since when everyone holds a CD, one finger passes through the central hole, and the other fingers hold the outside of the CD. If your hands are sweaty, sweat stains will easily stay in the interlayer, and over time, they will oxidize. No damage can be seen on the surface of an oxidized optical disc with the naked eye. To avoid this kind of artificial oxidation, you can take the following measures. After every time you take the disc, remember to wipe those areas clean with a dry cloth. There is another reason why the disc can be oxidized. If there is too much moisture in the air, it will invade the oxidized disc from the interlayer. To avoid this, you can only use transparent paint or a green oil-based marker to coat the outer side and inner ring of the interlayer with a layer of protection. After the film is dry, you can do it. If you don't have the conditions to do this, you have to wipe the interlayer with a dry cloth regularly.

The reason for photochemicalization is: this is for green disks for CD-R recording disks, because most of the disks on the market are green disks (aqua blue disks and platinum disks actually also belong to the ranks of green disks), and Green discs are very sensitive to strong light. Strong light can cause chemical changes in the recording layer of the green disc, leading to "actinic change." Therefore, try to avoid sunlight or high-wattage light bulbs irradiating the CD-R green disc for a long time.

Deformation: The so-called deformation mainly refers to two aspects: (1) The disc is not round. (2) The disc is uneven. For the former, the probability of occurrence is very small, so I won’t talk about it here; for the latter, I want to focus on it: everyone has used some CD cases with poor quality. Is it difficult to put the disc in or take it out? Does the case "bite" the disc so tightly that you have to force it out of the case? The problem is here, when you exert force, the disc will bend invisibly in an arc. It is strange that the disc does not deform over time. Therefore, please do not use a CD case that "bites" the disc very tightly! (In addition, this kind of CD case can also easily cause the center hole of the disc to crack. If the center hole of the disc is cracked, never put it in the optical drive for reading, because the "centripetal force" of high-speed rotation is very large, which can easily cause the disc to "explode" . )

Storage of discs

The actual life of discs (including burnable discs and music discs) is much shorter than what the manufacturer claims, and some people use incorrect storage methods. The data stored on the burned disc for several years has been lost. For example, if you leave an ordinary burned disc in the sun for a few hours, the quality will deteriorate until it is scrapped. If the information layer of the disc is oxidized, that part of the information will not even have the chance to be scrapped, so a good storage environment must be created to better extend its life.

The cheaper way to store discs is to use round disc tubes or disc bags. It is best to place the discs vertically. If placed horizontally in a CD case, the stress-bearing area is small and it is easy to deform and difficult to find. If they are overlapped and placed horizontally in other packages, they will also be easily deformed.

Moisture-proof boxes are generally divided into electronic type and desiccant type. The former is expensive, while the latter can be bought in the supermarket. A plastic moisture-proof box, a single independent type. It is best to use a reusable desiccant. Silica sand (also called water glass) that knows the degree of water absorption can be purchased in some stores that sell photography equipment and chemical supplies. It is blue when dry and turns pink when it absorbs water. At this time, it can be fried in a pot, dried in a microwave oven, dried in the sun and other methods to return it to blue. You don’t need too much, just wrap a little in something breathable like cloth and put it in a moisture-proof box.

How to repair a disc

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< p>What can be repaired if the optical disc is damaged is probably the following aspects:

1. Scratch repair on the "light" side of the optical disc (transparent polycarbonate):

(1) Use toothpaste. When using this method, please pay attention: not all toothpastes can remove scratches. Most toothpastes have great abrasion characteristics, but will make the disc more scratchy. Therefore, it is recommended to use toothpaste that is less abrasive to teeth to clean the disc. Recommended brands such as "Colgate", "Mianlianzhen" and "Crest". The specific method is: put the disc with the shiny side up (nonsense) on a dry towel to prevent it from sliding. Then use cotton wool with a relatively high purity, dip it in some toothpaste, wet it with some water, apply a little force to the scratched area of ??the disc, and wipe the scratches in a rotating manner (not rotating the disc!) until the scratches become the shallowest.

(2) In fact, there is a "Sihai brand" disc repair agent (special organic solvent) on the market that is specially used to remove scratches, which can effectively remove scratches. Note when using: When you first buy it, the contents in the bottle are layered and must be shaken before use. The wiping method is the same as before. Special note: This stuff is poisonous, boys should be given to it, and they should wash their hands after use. Girls should not play with it casually.

^v^

(3) There is a kind of anti-mosquito bite and refreshing medicine in the drugstore called "Ertian Oil" (note: not Fengyoujing). This medicine can also remove scratches, but when used Don't use too much, otherwise it will be counterproductive. The wiping method is the same as before.

(4) There is a special disc polishing machine on the market, but the price is...not recommended. Because the disc will become thinner.

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Introduce the method of cleaning the CD:

< p> (1) If there are only fingerprints on it, use glasses cloth or special silk brush to solve it.

(2) If there are oil stains or unknown dirt on it, put it boldly in the basin, pour an appropriate amount of "White Cat" or "Liby" dishwashing liquid, and add water, cover the disc, then take cotton wool and gently wipe away the oil or dirt in the water. Then, take it out immediately, rinse it with clean water, then shake off the water, and then use dry cotton to absorb the water droplets on the disc. Especially the water on the outer side of the disc and the entrance of the interlayer of the inner ring must be wiped dry. To prevent oxidation. Don’t worry, water won’t invade the mezzanine so quickly.

Warning: Never use "alcohol", "ether", "recorder head cleaner" and other organic solvents to clean the disc! ! Otherwise, you will die miserably!

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2. The side with printed text (paint protective layer ) Scratch (translucent) repair;

As mentioned before, once the paint protective surface with printed text is scratched, it will damage the reflective layer at least, or damage the data recording layer and cause damage to the optical disc at worst. scrapped! Regardless of whether the reflective layer is damaged or the data recording layer is damaged, the phenomenon we see is "light transmission". For optical discs that have damaged the data recording layer, we have no choice but to give up;

In many cases, only the reflective layer is damaged and the data layer is not damaged. For the situation where only the reflective layer is damaged, we still have ways to remedy the situation:

(1) Method 1: Buy a bottle of silver spray paint and keep it on standby. Wipe the disc clean and place it on a long piece of paper (printed side up, glossy side down, don't put it upside down), then spray a thin layer of silver spray paint on it, and then spray the second layer after it dries. Let it dry again and spray on the final third coat. Finally, leave it for 24 hours until it is completely dry. The principle of this method is to use the reflective component of silver spray paint to act as a "reflective layer", and the effect is still good. (If you don’t have silver, you can use green or blue spray paint instead, but the effect will be worse.)

(2) Method 2: If you don’t buy spray paint, you can buy green or blue spray paint Oil-based markers are applied to the scratched "light-transmitting" areas to replace the protective layer of paint, which also plays a role in the reflection of laser light. However, the effect is not better than the first one.

(3) Method 3: Use the "silver mirror reaction". (I forgot the equation, sorry.) High school students, give it a try.

(4) Method 4: Directly attach the "stickers" you usually collect to the "transparent" CD, preferably the silver "laser anti-counterfeiting label".

3. Repair of deformed discs

(1) Method 1: Find two clean, flat pieces of glass that are larger than the disc, clamp the deformed disc, and then place heavy objects on it. Above, press it for a week. It works great!

(2) Method 2: Clip the deformed CD into a thicker book, then put a heavy object on it and press it for a week. OK!

What kind of disc damages the optical drive (CD player)

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(1) A disc with non-standard thickness can damage the optical drive

We all know that the thickness of a standard CD-ROM disc is 1.2 mm. The center-mounted card hole clip can just hold a disc of this thickness. If the thickness of the CD-ROM disc is less than 1.2 mm, it will cause the disc to slip due to insufficient clamping when rotating at high speed, causing the optical drive to read data incorrectly. At the same time, the center spindle motor of the optical drive will be overstressed, which will cause the disc to become damaged in the long run. Damage; if the thickness of the CD-ROM disc is greater than 1.2 mm, it will cause the disc to be far away from the best focus point of the laser head when it is read, causing the laser head focusing circuit to be in a highly focused state at all times, which will cause the laser head to be damaged in the long run. The life of the main parts is greatly shortened. Usually we are more likely to encounter discs with a thickness less than 1.2 mm. This is the result of cutting corners by the people who make the discs. "Extra-thick" discs are relatively rare and usually appear in genuine software or CDs.

For discs that are not thick enough, we can only put a protective film on it to increase its thickness. We have no choice; for "extra-thick" discs, we can only use a special "disc polishing machine" To thin it out.

(2) A disc with a non-standard center hole may damage the optical drive

The standard center hole of a CD-ROM disc is 15 mm. If the hole is too small, the center of the disc may become jammed. The hole cannot be completely inserted into the spindle motor clamp, which will also cause the disc to be far away from the best focus point of the laser head when it is read, shortening the life of the main part of the laser head, and the disc is also prone to slipping; if the hole is too large, the spindle will The motor clamp is not easy to clamp the disc and will also cause the disc to slip.

For a disc with a center hole that is too small, we cannot artificially enlarge the center hole, because it is difficult to repair it by hand to make it as round as before, and it is easy to over-expand it.

(Unless you have the iron and blood egg carving skills.)

(3) A disc that has a scratch on the "light" side (transparent polycarbonate) will be damaged. Greatly shortens the life of the optical drive

As you can see from the previous figure, after the laser from the optical drive laser head reaches the data layer of the optical disc, it will be reflected back by the reflective layer to obtain the data. If the transparent polycarbonate is scratched, the laser will be inaccurately "refracted" or "diffusely reflected" on the uneven surface and cannot accurately focus on the data layer. In this way, the optical drive will increase the laser emission power, increase the focusing current and focus repeatedly to read the disc data. Over time, the laser tube of the laser head will soon age and the focusing circuit will be "tired".

(4) Scratches on the side with printed text (paint protective layer), that is, a "transparent" disc, will also damage the optical drive. If the paint protective layer is scratched, the reflective layer will fall off, and the laser cannot It will be accurately reflected back and return an incorrect code to the optical drive. The optical drive will mistake it for poor focus and will also increase the laser emission power and focus current to focus repeatedly in an effort to read the disc data. The effect is the same as before.

(5) A deformed disc will seriously threaten the "life" of the optical drive

The deformation mentioned here means that the disc is uneven. When such a disc is placed in the optical drive, the following results will occur:

A. Due to the unevenness, the center of gravity of the optical disc is offset. High-speed rotation will put a huge force on the optical drive spindle motor shaft, which can easily cause the motor shaft to bend! You can imagine the consequences yourself!

B. Due to unevenness, the high-speed rotating disc will "fluctuate" up and down, and it is easy for the disc to "hit" the laser head! That is, the laser focusing lens will be distorted or scratched by the uneven disc!

So, please be careful when using deformed discs! ! !