What is the head of a hard drive? What is a hard disk head

The hard disk head is the key component of the hard disk to read the data, its main role is to convert the magnetic information stored on the hard disk platter into electrical signals to transmit outward, and its working principle is to use the principle that the resistance value of special materials will change with the magnetic field to read and write the data on the platter, the quality of the head largely determines the storage density of the hard disk platter. At present, GMR (Giant) is more commonly used

magneto

Resisive) giant reluctance heads, GMR heads use a better magnetoresistive effect of materials and multi-layer thin film structures, which are more than the previous conventional heads and MR (Magneto

Resive) reluctance heads are more sensitive, and the relative change in magnetic field can cause large changes in resistance values, thus achieving higher storage density.

The magnetic head is a tool in the hard disk to read and write the platter, and it is one of the most delicate parts of the hard disk. The head is made with a coil wound around the core. When the hard disk is working, the head reads the data by sensing the change in the magnetic field on the rotating platter; Data is written by changing the magnetic field on the platter.

In order to avoid the wear and tear of the head and the platter, in the working state, the head is suspended above the high-speed rotating platter, without direct contact with the platter, only after the power is turned off, the head will automatically return to the fixed position on the platter (called the landing zone, where the platter does not store data, is the starting position of the platter).

Due to the nature of the head's operation, the requirements for its magnetic sensing sensitivity and precision are very high. The earlier magnetic head used ferromagnetic material, which was not very ideal in magnetic induction sensitivity, so the capacity of a single disk in the early days was relatively low, and the track density on the disk was large if the capacity of a single disk was large, and the magnetic head induction degree was not enough, so it could not accurately read the data. As a result, the capacity of the early hard drives was limited.

With the development of technology, magnetic heads have made great strides in magnetic sensing sensitivity and precision.

Initially, the head is read and write together, which requires the manufacturing process and technology of the head, and for the personal computer, in the process of exchanging data with the hard disk, the reading data is much faster than the writing data, and the characteristics of the read and write operations are completely different, which also leads to the reading and writing separation of the head, which works separately and does not interfere.

The magnetic head knocks on the plate, which can be understood as those gramophones in the old days, don't they have a head to read on the stack, and if the head is not good, it can't be put up and down, or the disc is pitted.

Figurative analogy: The hard disk reads and writes information by the head to scan the track, and the head knocks on the plate, which means that the head is knocking on the track, and the head or track is broken, which is the legendary bad track.

If it is a logical bad sector, it can be repaired, but if it is a physical bad sector, it can only be replaced.

Generally, the recovery of data depends on the size of the data and the degree of damage to the file, ranging from hundreds to tens of thousands.

It's the thing on the hard drive that reads data from the disk, like the one on an old record player.

A head that reads platter data.

What is a hard drive head? Take a deep dive into computer hardware.

In modern computer technology, the hard disk head is a very important component. This small hardware component is related to the storage and running speed of the computer. However, for the average user, few people really understand what a hard drive head is and what it does.

What is a hard drive head?

A hard disk head is a device that is installed directly on a hard disk and is used to read or write data magnetically. It is said that the number of hard disk heads in the world can be counted in billions, as it is one of the foundations of modern device storage.

How do hard drive heads work?

Each disk on the hard disk has a magnetic coating, and the magnetic coating is divided into small blocks, and each small block is called a sector. The magnetic head uses magnetic force to read and write these sectors, and when the magnetic head is very close to the disk surface, the magnetic force acts on the sectors.

There are two types of hard disk heads: single heads and multiple heads. A single head is usually used to store smaller files such as documents, **, etc.; And multiple heads are suitable for storing large files, such as **, audio, etc.

Application of hard disk heads.

The hard drive head is very important in the overall computer system because it is the basis on which the computer stores data. With the hard disk head, we can store and read a wide variety of data. However, there are also some problems with the hard disk head, such as the failure of the head or the insufficient magnetic force between the head and the disk surface may cause the hard disk to not work.

Summary. Although the specific function of the hard disk head is different from other hardware devices, it undoubtedly plays an important role in storing and reading data in the computer. With the continuous update of computer technology, the design and manufacture of hard disk heads are also constantly improving, from single heads to multiple heads and so on.

Today's hard drive heads are capable of storing large amounts of data, while also improving the efficiency of storing and reading data.

3. The total head refers to the part that reads the data on the magnetic medium by the magnetic principle. Common magnetic heads include hard disk heads, tape recorder heads, etc. The hard disk head is the key component of the hard disk to read the data, its main role is to convert the magnetic information stored on the hard disk platter into electrical signals to transmit outward, and its working principle is to use the principle that the resistance value of special materials will change with the magnetic field to read and write the data on the platter, the quality of the head largely determines the storage density of the hard disk platter.

At present, the most commonly used is GMR (Giant Magneto Resistive) head.

The head of the hard disk is made of coils wound around the core, and the initial head is a combination of reading and writing, and the amplitude of the signal is sensed through current changes. For most computers, in the process of exchanging data with hard disks, read operations are much faster than write operations, and read and write operations are two operations with different characteristics, which prompts hard disk manufacturers to develop a read-write split head.

1. When the hard disk drive is powered on, the control circuit is used to initialize the work, after the initialization is completed, the spindle motor will start and rotate at high speed, and the trolley mechanism installed in the magnetic head will move, and the floating magnetic head will be placed on the 0 channel on the surface of the platter, and it will be in the starting state of waiting for instructions. When the interface circuit receives the command signal from the microcomputer system, the command signal is driven to click and send out a magnetic signal through the pre-amplification control circuit, and the disc data is correctly positioned according to the magnetic head that induces the change and decodes the received data information, and then transmits to the interface circuit through the amplification control circuit and feeds back to the host system to complete the instruction operation. When the hard disk is powered off and stops working, under the action of the counter-torque spring, the floating head resides in the center of the disk.

2. The data of the hard disk is saved on the platter, which is covered with magnetic materials. We all know that magnetism has two levels, north and south, which can represent 0 and 1 in binary, and the storage and operation of computer data are carried out in binary form. The process of writing data is actually the process of changing the magnetic poles of the magnetic material on the surface of the hard disk platter through the magnetic head; The reading data is de-induced by the magnetic head.

process of change. This is where the head plays an extremely important role, and it is also the most expensive part of the hard drive.

3. The early head is an all-in-one electromagnetic induction head, but the reading and writing of hard disk data are two completely different operations, so this two-in-one head must take into account the two characteristics of reading and writing in the design, resulting in design limitations. The MR head (reluctance head) adopts a separate head structure, and the writing head still uses the traditional induction head (MR cannot write), and the reading head uses a new type of MR head or GMR head, so the write operation is completed by the induction head, and the read operation is completed by the MR head (cargo GMR head). In this way, the design can be optimized for the different characteristics of the two, and better read and write performance has been achieved.

In addition, the MR head senses the signal through the change of the resistance value, so it is quite sensitive to the change of the signal, and the accuracy of reading the data is very high. And since the amplitude of the read signal is independent of the track width, the track can be made very narrow, thus increasing the capacity of the platter.

The head is a key device for reading and writing information. Information is recorded on the platter, which is read or written to the platter through the head.

The hard disk head is the key component of the hard disk to read the data, its main role is to convert the magnetic information stored on the hard disk platter into electrical signals to transmit outward, and its working principle is to use the principle that the resistance value of special materials will change with the magnetic field to read and write the data on the platter, the quality of the head largely determines the storage density of the hard disk platter. At present, the most commonly used is GMR (Giant Magneto Resisive) head.

To put it bluntly, it is: similar to VCD, the bald head in ***, used to read data!

Floating head.

Contact head.

Fixed head.

Swivel head.

Correct Answer: Floating head.

CPP-GMR head, the full name of Chinese is the vertical plane current mode of large anti-magnetized head, it is a Japanese computer manufacturer Fujitsu company developed a new type of read-write disk head technology. Hard drives using this technology can have a recording density of up to 300 GB per square inch. The increase in hard drive recording density will increase the storage capacity of laptops and desktops, while ** will only increase slightly.

According to Fujitsu, the current storage capacity of each disk slice is 30 GB for the inch hard disk, and if this new disk technology is commercialized within two to four years, it will increase the storage capacity of each disk slice to 180 GB, that is, three times the current capacity per disk slice. This groundbreaking new disk head is more sensitive to signal than existing GMR heads and reads and writes data three times more compactly than existing GMR heads. Fujitsu expects to commercially produce drives based on this CPP-GMR head within two years, primarily in PCs and notebook PCs, especially in drive-based consumer electronics such as gaming consoles and personal** video recorders in anticipation of a booming market.

According to Fujitsu, high-capacity inch hard drives will eventually replace bulky inch hard drives. According to the International Disk Drive Equipment Manufacturers Association (IDEMA), disk storage capacity has increased even faster than data processing capacity over the past decade or so, but manufacturers are finding it difficult to turn their expertise into real profits. Hard drive storage** has fallen from $1 per megabyte in 1988 to 1 cent per megabyte today, and the number of independent hard drive manufacturers has decreased from 75 to 13 today.

The full English name of OAW is English optically assisted Winchester, that is, optically assisted Winchester. This technology is a new type of head technology being developed by Seagate that combines a traditional magnetic read/write head with a low-intensity laser beam that enters the head through an optical fiber and is reflected to the disk surface through a micromotor-driven mirror to achieve precise head positioning. Seagate believes that OAW technology can write more than 105,000 tracks in a 1-inch wide range and can reach a single hard disk capacity of more than 36GB, but it will take two or three years for the technology to enter the practical stage.

However, the capacity of a single disk of hard disks has reached 1TB, so it seems that the market prospect of OAW technology is not optimistic.

AMR (Anisotropic Magneto Resistive) In the mid-90s, Seagate introduced hard drives using AMR heads. AMR heads use TFI heads for writes, but thin strips of magnetic material are used as read elements. In the presence of a magnetic field, the resistance of the thin strip changes with the magnetic field, resulting in a strong signal.

The hard disk interprets the change in resistance of the thin strip due to the change in the polarity of the magnetic field, improving the read sensitivity. AMR heads further increase areal density and reduce the number of components. Since there is a limit to the amount of resistance change in AMR films, AMR technology can support a maximum of square inch recording density, so there is a limit to the sensitivity of AMR heads.

This led to the development of GMR heads.

GMR (Giant Magneto Resistive) GMR heads inherit the reading and writing technology used in TFI heads and AMR heads. However, its read head exhibits higher sensitivity to magnetic changes on the disk. The GMR head is composed of 4 layers of conductive material and a thin film of magnetic material

A sensing layer, a non-conductive interposer, a magnetic plug layer, and an exchange layer. The sensitivity of the GMR sensor is 3 times greater than that of the AMR head, so it can improve the density and performance of the platter.

The number of heads in a hard drive depends on the number of disks in the disk, and data is stored on both sides of the disk, so one platter corresponds to two heads in order to work properly. For example, if a hard disk with a total capacity of 80GB uses a single disc with a capacity of 80GB, there is only one platter, and there is data on the front and back of the platter, which corresponds to two heads; A hard drive with the same total capacity of 120GB has only three heads if it uses two platters, and one of the platters has no head on one side.