JPH0814928B2 - Disk drive device - Google Patents

Description

The present invention relates to adjusting the timing of an index signal in an index signal detection circuit of a flexible disk magnetic recording device.

[Conventional technology]

In the flexible disk magnetic recording device, the timing adjustment of the index signal is a necessary item in order to guarantee the compatibility of the flexible disk. Usually, the index burst signal written on the reference disk called alignment disk is measured from the trailing edge of the index signal and the time is called the index burst time, and adjusting this value is the timing adjustment of the index signal or This is called index burst adjustment.
As this adjusting method, a means for adjusting the timing of the index signal by adding an electric delay circuit to the index signal detecting circuit is described in Japanese Utility Model Application No. 60-155046.

[Problems to be solved by the invention]

In the prior art, when there are a plurality of flexible disk rotation speed controls, the index burst time T shown in FIG. 3 has a large change amount, T'if the rotation speed is fast, and T'if the rotation speed is slow. In the present invention, it is an object of the present invention to have a wide adjustment range even when a plurality of flexible disk rotation speed controls are performed.

Further, in the case of having a plurality of rotation speeds, it is possible to widen the adjustment range by providing a plurality of electric adjusting means for each rotation speed, but it is necessary to perform the adjustment for each rotation speed, and therefore the reliability is high. There was a problem that it was inferior in terms of performance and miniaturization.

[Means for solving problems]

The disk drive device of the present invention selects one speed from at least two different predetermined speeds based on the speed selection signal to rotate and drive the disk-shaped recording medium, and perform recording and / or reproduction on the disk-shaped recording medium. In the disk drive device for performing the rotation reference position signal generating means for generating a rotation reference position signal based on the rotation of the disk-shaped recording medium, and the rotation reference position signal by a delay amount determined by a delay amount setting element. An analog delay unit for delaying, a plurality of delay amount setting elements, and a delay amount changing unit for changing the delay amount by selecting connection of the plurality of delay amount setting elements based on the speed selection signal. Is characterized by.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a circuit diagram for correcting an electrical delay circuit by a plurality of rotation speed switching signals in an index signal detection circuit according to an embodiment of the present invention, and FIG. 2 is a timing diagram thereof. The collector 4 which is the index signal detecting element Q ₁ is connected to Vcc by the resistor 3 and is also connected to the (−) side input terminal of the delay time setting monomulti ₁ . The output of the monomulti 1 is connected to the (+) side input terminal of the monomulti 2. The delay time setting capacitor 9 of the monomulti 1 is connected to the ground at one end, and the other end is connected to the delay time adjustment variable resistor 10 and also to the rotation speed switching correction capacitors 7 and 8. The other end of the delay time adjustment variable resistor 10 is connected to Vcc. The other ends of the rotational speed switching correction capacitors 7 and 8 are connected to the collector side of the switching element 5 for the rotational speed switching signal 1 and the collector side of the switching element 6 for the rotational speed switching signal 2, respectively. Mono Multi 2 delay time setting capacitor 11
Has one end connected to the ground and the other end connected to the delay time setting resistor 12. The other end of the delay time setting resistor 12 is connected to Vcc.

When the index signal detecting element Q ₁ is turned on, the delay time ΔT set by the delay time setting capacitor 9 and the delay time adjusting variable resistor 10 becomes LO from the output of the monomulti 1.
W pulse is output. When the LOW pulse rises from the output of the monomulti 1, the BIGH pulse is output from the output of the monomulti 2 with the delay time t set by the delay time setting capacitor 11 of the monomulti 2 and the delay time setting resistor 12. By using the Q output of the monomulti 2 as an index signal, the delay time adjustment variable resistor 10 is adjusted to change ΔT, and the index burst time T
Can be adjusted to a specified value.

Therefore, when the rotation speed is switched, the switching element 5 for the rotation speed switching signal 1 is turned on, so that the rotation speed switching correction capacitor 7 is connected in parallel with the delay time setting capacitor 9 of the monomulti 1. And the delay time of mono-multi is (T + α). Where variation α
Can be calculated as the product of the rotational speed fluctuation rate and the delay time adjustment value T. This is because the index burst signal is proportional to the rotation speed fluctuation. Therefore, the adjustment range of the index signal is 1 to 2 ms, which is the same as in the actual opening 60-155046.
Can be secured. However, in the case of the present embodiment, since the rotation speed switching signal 1 or 2 is turned ON, the rotation speed switching correction capacitors 7 and 8 are added in parallel to the delay time setting capacitor 9 of the monomulti 1. The delay time setting capacitor 9 of the monomulti 1 needs to be set at the fastest rotation speed among a plurality of rotation speeds.

〔The invention's effect〕

According to the present invention, the index burst time can be adjusted electrically stably and easily in a flexible disk magnetic recording device having a plurality of flexible disk rotation speeds, and the number of parts is not increased. Also,
Since it is possible to set a predetermined ratio at a plurality of rotation speeds by one adjustment, the adjustment time can be shortened and it is also suitable for automation.

[Brief description of drawings]

FIG. 1 is a circuit diagram for correcting an electrical delay circuit by a plurality of rotation speed switching signals in an index signal detection circuit according to an embodiment of the present invention, and FIG. 2 is a timing diagram thereof. Third
The figure is a timing diagram when a plurality of rotation speeds are switched in the conventional technique. 1,2 …… Monomulti 4 …… Index signal detection element Q ₁ 5,6 …… Switching element 7,8,9,11 …… Capacitor 10 …… Delay time adjustment variable resistor 3,12 …… Resistance

Claims (1)

[Claims] 1. A disk-shaped recording medium is rotationally driven by selecting one speed from at least two different predetermined speeds based on a speed selection signal, and recording and / or reproducing is performed on the disk-shaped recording medium. In a disk drive device, a rotation reference position signal generator that generates a rotation reference position signal based on rotation of the disk-shaped recording medium, and a plurality of delay amount setting elements that selectively use the rotation reference position signal ( 7, 8) and an analog delay means (1) for delaying an amount of delay determined by a common delay amount adjusting element (10) connected to the plurality of delay amount setting elements, and the plurality of delay units based on the speed selection signal. And a delay amount changing means (5, 6) for changing the delay amount by selecting the connection of the delay amount setting element.