KR910007448B1 - Detecting apparatus of the position of optical head unit - Google Patents

Abstract

The adjuster receives various discs having different sizes to reproduce the information data. The adjuster includes an operation bar (14) having a pair of pivots (A,B), adjusting angles (9,901) having guide rods (10,101), and a control plate (8). When the disc with certain size is inserted, the adjuster is adjusted to fix the disc according to its size.

Description

Head position detection device and method of optical disk driver

1 is a conventional head position detection circuit diagram.

2 is a conventional head position detection flow chart.

3 is a head position detection circuit diagram of the present invention.

4 is a head position detection flow chart of the present invention.

* Explanation of symbols for main parts of the drawings

10: head 20: microcomputer

30: D / A Converter OP1-OP2: Operational Amplifier

R1-R7: Resistor C1: Capacitor

L1: Actuator Coil D1: Diode

N1: Inverter

The present invention relates to an optical disk driver system, and more particularly, to an apparatus and a method capable of detecting the position of a head using a track seek signal.

In general, an optical disk driver is a kind of data storage device that records and reads data using a laser beam on a disk, and may assume much larger amount of data than a Floppy Disk Driver (FDD) or a Hard Disk Driver (HDD).

The conventional technique for detecting the position of the head in the optical disk driver has implemented the same method as in FIG. 2 using a circuit as in FIG. In the head 1, lenses for recording or reproducing the data on the disk using an optical signal and an object lens for connecting a beam to the disk among the lenses are included. There is an actuator to drive. The actuator drives the objective range horizontally or vertically to perform a focusing servo. In this case, since the actuator driving current of the head 1 is closely related to the current position of the lens, the position of the head can be known by knowing the magnitude of the current. To this end, a current generated in the head 1 and flowing in the actuator coil L1 is converted into a voltage by the resistor R1, and the voltage is digitally read so that the microcomputer 3 can read the voltage through the A / D converter 2. Convert to a value. The microcomputer 3 then reads the output of the A / D converter 2 to obtain a lens off set value. In this case, the lens offset means a displacement difference when no current flows through the actuator coil L1, that is, when the lens is positioned at the center of the head and when the lens position is moved from the center of the head due to the current. . In addition, the microcomputer 3 outputs track seek data to search for a predetermined track, and the data is converted into an analog signal through the D / A converter 4 and then applied to the actuator through the operational amplifier OP2. . At this time, in the head position detection method as described above, an A / D converter had to be used so that the microcomputer could recognize the current flowing in the head actuator coil. In addition, the microcomputer performed a separate lens offset program with the A / D converted data. There was a problem that the program was complicated.

Accordingly, an object of the present invention is to provide an apparatus and method for detecting a position of a head according to a state of a comparison signal after comparing a signal generated by a head actuator with a lens offset signal output from a microcomputer of an optical disk driver. .

Hereinafter, the present invention will be described in detail with reference to the drawings.

3 is a head position detection circuit diagram of the present invention, wherein the head 10 generates an actuator driving current according to the position of a range, generates data according to track seek and lens offset, and receives predetermined digital data to offset the range. A microcomputer 20 for adjusting a value, a D / A converter 30 for D / A converting data according to a track seek or lens offset generated in the microcomputer 20, an actuator coil L1, and a resistor R1. Means for converting the actuator driving current into a fixed reference voltage according to a current head position, an operational amplifier OP2, and resistors R3, R4, and R7. Means for converting the variable lens offset signal of the A converter 30 into a comparison voltage, and means for generating a comparison signal according to the state of the reference voltage and the comparison voltage, comprising an operational amplifier OP1 and resistors R5 and R6. And diode (D1) and phosphorus Is composed of emitter (N1) consists of a means for outputting to the microprocessor by converting the comparison signal into the digital data of a TTL level.

4 is a flow chart of the head position detection of the present invention, the first process of initializing the first data for the initial lens offset and the second data for the D / A conversion output to a predetermined value, and the first and second steps. Adding data and outputting a D / A conversion, receiving a signal compared with the current head position signal, and adding the first and second data when the comparison signal changes, and then converting the data into first data. The third process and the comparison signal has not changed, or after performing the third process and the second data divided by 2 to the second data and the first data is checked whether 0, and if not returned to the second process In step 4, and in the fourth process, a fifth process of setting the first date and time data as the lens offset value to 0 days is a fifth process.

The present invention will be described in detail with reference to FIGS. 3 and 4 based on the above-described configuration.

As the actuator of the head 1 drives, the current flowing in the actuator data coil L1 is converted into the second voltage by the resistor R1, and the high frequency is generated through the resistor R2 and the capacitor C1, which are integrated circuits. ) Noise of the component is removed.

At this time, the second voltage is a fixed voltage representing the current range of the stove and becomes a reference signal.

In this case, the microcomputer 20 outputs predetermined data when obtaining the lens offset or track seeking. In order to perform this function, the microcomputer 20 uses the D / A converter 30. That is, since the operation of obtaining the offset of the actuator is a preliminary operation for moving the actuator, the operation of obtaining the actuator offset and the generation of the track jump signal for the track seek cannot be simultaneously performed. . Therefore, in the present invention, the D / A converter 30 generating the jump signal for the track seek is also used when performing the actuator offset. Therefore, when the data for the lens offset is generated in the microcomputer 20, it is converted into an analog signal through the D / A converter 30, and the signal is first converted through the operational amplifier OP2 and the resistors R7, R3, and R4. The first voltage is converted into a voltage signal and is a comparison signal as a variable voltage for offsetting the current lens position in the microcomputer 20.

Therefore, the operational amplifier OP1 compares the two voltage signals and generates a comparison result signal. A high signal is generated when the first voltage is large and a low signal is generated when the second voltage is large. At this time, the resistors R5 and R6 reduce the hysteresis. However, since the output of the operational amplifier OP1 has a level of ± 12V, it must be converted to a TTL level so that the microcomputer 30 can recognize it, which is performed through the diode D1 and the inverter N1. That is, if the voltage is ± 12V, the diode D1 is turned on, so only the voltage of 5V, which is the TTL level, is supplied to the inverter N1. If the voltage is -12V, the voltage of the 5V, which is TTL level, is inverted by the inverter N1. Occurs.

Then, the microcomputer 30 receives the output of the inverter N1, analyzes the state thereof, and then performs lens offset to detect the position of the head. Referring to the above process, first, the microcomputer 30 sets the first data, which is the offset value of the first lens actuator, to 0 in step (A), and the D / A converter as data for knowing the second voltage, which is the current lens position. The second data outputted at 30 is set in the internal memory at a predetermined value 80H. Thereafter, in step (B), first and second data set in step (A) are added, and in step (C), the addition data is output to the D / A converter 30. Then, as described above, the second voltage for the current head position generated by the actuator of the head 10 and the second voltage output from the D / A converter 30 are compared in the operational amplifier OP1. The signal is converted to the TTL level in the diode D1 and the inverter N1 and applied to the microcomputer 20. Then, the microcomputer 20 checks whether the output state of the inverter N1 is changed in step (D), which can be divided into two states.

First, when the first voltage is greater than the second voltage (that is, when the output of the inverter N1 is in the "low" state), the process proceeds to step (F) to divide the initially set second data into two and store it in the memory. In the next step (G), it is checked whether the value set initially is 0. At this time, if the initial value is not 0, the process returns to step (B) and repeats the above steps, and at some point during the repetition (second voltage> first voltage), the output of inverter N1 is " high " do.

Then, in step (D), the output change of the inverter N1 [second voltage> first voltage: the output of the inverter N1 is “high” state is recognized. The first and second data are added to make this data the first data for lens offset. Subsequently, the process proceeds to step (F) to repeat the state of the initial value to reduce the size difference between the first and second voltages by dichotomously reducing the second data set initially. It is possible to obtain an approximate first voltage. In this case, since the second data value becomes zero, the microcomputer 20 recognizes the step (G), and in step (H), the microcomputer 20 recognizes the first data value at the time when the second data becomes zero. Accept as the offset value of the lens and end.

The lens offset value is generated as a first voltage, which is almost equal to the second voltage generated in the actuator of the head 10.

As described above, an optical disk driver generates a lens offset signal through a D / A converter that generates a track seek signal, compares the signal with a current head position signal generated by an actuator of the head, and compares the comparison signal with a microcomputer. The position of the head can be detected by reading and analyzing the state, which does not require a separate A / D conversion function, resulting in the system miniaturization and cost reduction, and the program can be simplified. .

Claims (2)

A head generating an actuator driving current according to the position of the lens, a track seek and a data generated according to the lens offset, a micom receiving the predetermined digital data to adjust the range of the range and a track seek generated from the micom, or A D / A converter for D / A conversion of data according to lens offset, an actuator coil, a resistor and a capacitor, and means for converting the actuator driving current into a fixed reference voltage according to the current head position, and an operational amplifier and a resistor. Means for converting the variable lens offset signal of the D / A converter into a comparison voltage, an operational amplifier and a resistor, means for generating a comparison signal according to the state of the reference voltage and the comparison voltage, a diode and an inverter. And converts the comparison signal into digital data of TTL level and outputs it to the microcomputer. Is a means for detecting the head position of the optical disc driver. A microcomputer for generating a lens offset value according to a predetermined comparison signal, means for generating a variable signal according to a lens offset by D / A converting the output of the microcomputer, means for generating a fixed reference signal according to the position of the current head; A head position detection method of an optical disk driver having a means for generating a comparison signal according to a state of the reference signal and a variable signal, the method comprising: a variable data for initializing first data for an initial lens offset and performing D / A conversion; A first process of setting two data to a predetermined value, a second process of adding the first and second data to output a D / A conversion, and receiving a signal compared with the fixed reference signal; A third process of reducing the second data until the state change when there is no change of state, and adding the current first and second data to the first data when the comparison state changes in the third process and then making the second data; And a fifth process of decreasing the lens until the second becomes zero, and a fifth process of selecting a lens offset value from the first data value when the second data becomes zero. Way.

Images