KR100482351B1 - Spindle motor presence / absence detection circuit and detection result output method - Google Patents

Abstract

end. TECHNICAL FIELD This invention relates to a circuit and method for detecting spindle motor rotation of a hard disk drive.

I. The present invention is to provide a spindle motor rotation detection circuit and a detection result output method that can detect the rotation of the spindle motor during the erasure of bad servo information in the manufacturing process of the hard disk drive.

All. Summary of the Invention Solution of the Invention: An index pulse generation unit for receiving an output signal derived from a drive coil of a spindle motor and dividing at a predetermined division ratio to generate an index pulse, and a switching on-off operation by the index pulse. In the hard disk drive having a part, a signal indicating an error state of the spindle motor when the index pulse input through the switching unit for a predetermined time after the spindle motor is driven, and the counting value has a value less than the desired target value. Characterized in that the output to the outside.

la. Important use of the invention: It can be used in the manufacturing process of hard disk drive.

Description

Spindle motor rotation detection circuit and detection result output method

The present invention relates to a servo information erasing process of a hard disk drive, and more particularly, to a circuit and a method for detecting the presence or absence of rotation of a spindle motor during servo information erasing and outputting the detected result to an external device.

Hard disk drives include HDA (Head Disk Assembly) assembly, Servo light process, FUNCTION TEST, Burn-In process, FINAL TEST process, shipping inspection and packaging process. It goes through a series of manufacturing processes and is shipped as a finished product. The servo light process in the series of manufacturing processes described above includes a test process for confirming the recording state of the servo information. If it turns out that the servo information is recorded incorrectly during the test, delete the bad servo information and perform the servo write process again.

FIG. 1 is a flowchart illustrating a servo information erasing process for explaining a servo information erasing process during a manufacturing process of a hard disk drive. Referring to FIG. 1, first, an operator of a manufacturing process line selects and mounts a bad HDA in which servo information is recorded incorrectly as a first step (1) and mounts it on a jig. The operator then drives the spindle motor by connecting the spindle motor connector to the spindle motor drive as a second step (II), and the operator advances the HDA mounted jig between the magnet gaps as a third step (III). The magnet gap means a space between magnets stacked on each of the upper and lower layers of the servo information eraser. After a certain period of time, the worker sends the HDA-mounted jig from the magnet gap as a fourth step (IV) measure. As a fifth step (V), the HDA mounted on the jig is detached and moved back to the servo light process.

However, in the above-mentioned servo information erasing process, the rotation of the spindle motor may act as an important factor for erasing the servo information. The reason for this is that if the spindle motor does not rotate normally, afterimages occur because servo information recorded in concentric circles is not completely erased. Therefore, in the above-mentioned servo information erasing process, it is impossible to check whether or not the rotation of the spindle motor is normal. Therefore, if the servo information erasing process is performed while the spindle motor is not driven, a problem arises that the desired servo information cannot be deleted. do.

Accordingly, an object of the present invention is to provide a spindle motor rotation detection circuit capable of detecting the rotation of the spindle motor when the defective servo information is erased in the manufacturing process of the hard disk drive.

Still another object of the present invention is to provide a method for outputting a spindle motor rotation detection result that detects the rotation of the spindle motor when the defective servo information is erased and outputs the detection result to the outside.

The present invention for achieving the above object is an index pulse generation unit for receiving an output signal from the drive coil of the spindle motor and divides at a predetermined division ratio to generate an index pulse, and switching on-off operation by the index pulse In the spindle motor rotation detection result output method of the hard disk drive having a switching unit,

Counting the index pulse input through the switching unit for a predetermined time after driving the spindle motor, and outputs a signal indicating the error state of the spindle motor to the outside when the counting value has a value less than the desired target value. .

Hereinafter, an operation according to an exemplary embodiment of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 2 is a circuit diagram illustrating whether the spindle motor is rotated according to an embodiment of the present invention, and FIG. 3 is a timing diagram of index IDX pulses output from the index pulse generator 35 of FIG. 2. And Figure 4 shows a control flow diagram to output the spindle motor rotation detection result according to an embodiment of the present invention to the outside.

First, referring to FIG. 2, the spindle motor rotational detection circuit according to an embodiment of the present invention divides the output signal waveform largely derived from the U-phase coil of the spindle motor at a predetermined division ratio, thereby indicating an index of one rotation period of the spindle motor. (IDX) P1 and P2 terminals of the microcomputer 40 by the index (IDX) pulse generator 35 generating the pulses and the index (IDX) pulses output from the index (IDX) pulse generator 35. Count the number of inputs of the index (IDX) pulse through the photo coupler (PT) to turn on / off and the on / off operation of the P1 and P2 terminals, and detect the presence or absence of the rotation of the spindle porter according to the counting result. It is composed of a microcomputer 40 that outputs to the outside.

Hereinafter, the configuration of the known index (IDX) pulse generator 35 will be described with reference to FIG. 2. The index (IDX) pulse generator 35 may include a 74LS14 inverter 10 manufactured by MOTOROLA, and 74LS74 consists of dual D flip-flops (20, 30). That is, the inverter 10 inverts the output signal induced from the U-phase coil while driving the spindle motor and outputs it to the clock stage CLK of the D flip-flop 20. Each of the dual D flip-flops 20 and 30 latches and outputs a signal applied to the D input terminal at the rising edge of the clock signal. If the waveform of the output signal induced from the U-phase coil of the spindle motor is as shown in FIG. 3, the timing of the index IDX pulse generated through the dual flip-flops 20 and 30 is shown in FIG. 3. As shown. As such, the index IDX pulse output from the index IDX pulse generator 35 is applied to the anode of the light emitting diode through the resistor R1 to turn on the light receiving transistor. If the P1 and P2 terminals respectively connected to the collector and the emitter of the light receiving transistor are connected in the microcomputer 40, the microcomputer 40 is indexed by the turn-on and turn-off operation of the light receiving transistor. You can count the number of (IDX) pulse inputs.

Hereinafter, a process of detecting the rotation of the spindle motor by counting the number of inputs of the index IDX pulse will be described with reference to FIG. 4. First, in order to erase the bad servo information, the operator connects the spindle motor connector to the spindle motor drive as the second step (II) of the servo information erasing process and drives the spindle motor. Accordingly, the microcomputer 40 starts to check whether there is an input of the index IDX pulse in step 50 of FIG. 4. As described above, the checking method may be determined whether the P1 and P2 terminals are connected. If the index (IDX) pulse is input in step 50, the microcomputer 40 proceeds to step 60 and counts the index (IDX) pulse through whether P1 and P2 terminals are connected for a predetermined time. The predetermined time may be determined as the minimum time required for erasing all the servo information recorded on the disk by the rotation of the spindle motor. Therefore, after the predetermined time has elapsed, the microcomputer 40 proceeds to step 70 and checks whether the counting value of the index IDX pulse is less than or equal to the target value. The target value is set to an approximate value smaller than the number of index (IDX) pulses generated when the spindle motor rotates normally for a predetermined time. On the other hand, the microcomputer 40 outputs an error signal for informing the operator that the spindle motor is not rotated or normally driven in step 80 and ends the control process according to the embodiment of the present invention. By outputting the error signal, the operator can remove the obstacle of the spindle motor and then proceed with the servo erasing process again. On the other hand, if the counting value of the check result index (IDX) pulse of step 70 exceeds the target value, the microcomputer 90 proceeds to step 90 to output the servo information erase completion signal and ends the control process according to the embodiment of the present invention. . As the output of the servo information erase completion signal, the operator may determine that the defective servo information is completely erased as the spindle motor rotates normally.

As described above, according to the present invention, since the presence or absence of rotation of the spindle motor can be checked in the servo information erasing process, there is an advantage in that the deletion of the defective servo information can be confirmed. In addition, it is possible to check whether the spindle motor is rotating during the servo information erasing process, so that it is possible to check the normal operation state of the spindle motor.

1 is a flowchart of a servo information erasing process for explaining a servo information erasing process during a manufacturing process of a hard disk drive.

Figure 2 is a spindle motor rotation detection circuit diagram according to an embodiment of the present invention.

3 is an index (IDX) pulse generation timing diagram output from the index pulse generator 35 in FIG. 2.

Figure 4 is a control flow diagram for outputting the spindle porter rotation detection result in accordance with an embodiment of the present invention.

Claims (2)

In the spindle motor rotation detection circuit, An index pulse generator for generating an index pulse by receiving an output signal from the drive coil of the spindle motor and dividing the output signal at a predetermined division ratio; A switching unit for switching on and off by the index pulse; And a control unit for counting the index pulse input through the switching unit and outputting a state of whether the spindle motor is rotated to the outside.  Output of the spindle motor rotation detection result of the hard disk drive having an index pulse generator for generating an index pulse by receiving the output signal from the drive coil of the spindle motor and a switching unit for switching on and off by the index pulse In the method, Counting an index pulse input through the switching unit for a predetermined time after the spindle motor is driven; And outputting a signal indicating an error state of the spindle motor to the outside when the counting value has a value less than a desired target value.