JPH0454601Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a density compatible circuit switching structure in a magnetic disk device, and particularly relates to a density compatible circuit switching structure in a magnetic disk device that can easily and reliably switch density compatible circuits. .

Prior Art In a magnetic disk device, depending on the type of recording density (specifically, single density, double density, etc.) of the magnetic disk that is the recording medium, a recording/reproducing signal amplification circuit in the device is required. It is necessary to change the amplification constant etc. This switching is automatically performed when a magnetic disk is inserted into the device, and conventionally there have been two switching methods as described below. That is, when a disk is inserted, a medium detection switch (a notch for detecting the density provided in the jacket of the magnetic disk being used or a cartridge) provided in the disk device is used to detect the type of density using a mechanical means such as a switch. and obtain a detection signal).

Switching is performed by a selection command signal supplied from the host device used.

There are two methods.

Here, the above two methods will be explained in more detail using the drawings. FIG. 7 shows the above-mentioned scheme. In the figure, the part consisting of resistor 1 and switch 2 is a changeover switch that detects the type (mode) of the magnetic disk, and as mentioned above, when the disk jacket or cartridge is inserted, the density of the magnetic disk is changed. The switching signal is generated by coming into contact with a correspondingly formed notch. The generated switching signal (H level DC voltage) is inputted to the signal identification terminal 6 of the control circuit 5 via the inverter 3 and the terminal 4, and the density switching signal is outputted from the output terminal 7. The density switching signal outputted from the output terminal 7 is supplied to an amplifier circuit or the like that performs recording/reproduction processing, and constants are changed in accordance with the density. In addition, if the terminals 8 and 9 are short-circuited, the interface connector 10 with the host device (for example, a personal computer) can be connected.
The configuration is such that a density identification signal can be supplied from the host device to the host device.

On the other hand, in the case of the above-mentioned method in which the density identification depends on commands from the host device, as shown in FIG. Density switching signal input terminal 1 of 5
2, and the control circuit 5 performs the same operation as in the above method. In this case, the density switching signal is exclusively controlled by commands from the host device.

Problems to be Solved by the Invention However, none of the conventional magnetic disk devices has a configuration in which both the above methods and the above methods are provided in one device. Since each magnetic disk device employing this method was manufactured separately, two manufacturing processes were required, complicating the manufacturing process, and resulting in poor manufacturing efficiency.

In addition, because there is incompatibility between magnetic disk devices using this method and magnetic disk devices using this method, if you try to change the density of the magnetic disk from, for example, single density to double density, or if you change the host device. In response to this, there was a problem in that a new magnetic disk device that was compatible with the changed density and method had to be purchased.

The present invention has been created in view of the above points, and has a structure that allows the above-mentioned methods to be used in common with a single magnetic disk device, and also allows switching between the methods and methods to be performed easily and reliably. It is an object of the present invention to provide a density-compatible circuit switching structure in a magnetic disk device that can be used.

Means for Solving the Problems In order to solve the above problems, in the present invention, in order to share magnetic disks having multiple types of densities (recording densities), the disk device A density compatible circuit switching structure in a magnetic disk device that switches circuits etc. installed in the magnetic disk device is installed in a pin header with the installation position selected at each vertex angle of a quadrilateral when viewed from above. With four connection pins,
The short circuit member is selectively connected to two of the four connection pins and short-circuited between the two connection pins.

Furthermore, the distance between the connecting pins is configured so that the lengths of at least three of the four sides of the quadrilateral formed by the pair of connecting pins are equal, and the shorting member is located between the positions corresponding to the three sides. It is configured so that three types of short-circuit connections can be selectively made with the connection pins.

Function The present invention has the above-mentioned configuration, and has a simple switching structure combining pin headers.
It can immediately correspond to any host device and magnetic disk, and the switching points are concentrated in one place.
Switching can be performed by operation, and erroneous connections can be prevented.

Embodiments Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a density-compatible circuit switching structure 13 in a magnetic disk device, which is an embodiment of the present invention.
(hereinafter simply referred to as a switching structure) is a circuit diagram of a density identification circuit 14 provided with a switching structure. Note that the configurations already shown in FIGS. 7 and 8 are designated by the same reference numerals and their explanations will be omitted.

The density identification circuit 14 shown in the figure uses a switching method using a medium detection switch (consisting of a resistor 1 and a switch 2) provided in the disk device described above, and a selection command signal supplied from a host device used together. The configuration is such that it can be used in common for both switching systems, and switching between each system is performed in the switching structure 13, which is the essential part of the present invention.

As shown in FIG. 2, this switching structure 13 is made up of roughly four connection pins 15 to 18 and a shot bar 19. The four connection pins 15 to 18 are implanted into two pin headers 20 and 21, two each, and are attached to a circuit board 22 installed inside the magnetic disk device. Further, each of the connection pins 15 to 18 is arranged at a position corresponding to each apex angle of a quadrilateral when viewed from above in a plan view. That is, each connection pin 15-1
Of 8, 15 and 16, 16 and 17, 17 and 18,
When looking at the four lines connecting 18 and 15,
These four lines are configured to form a rectangle. Furthermore, the spacing pitch between the connecting pins 15 and 16 (indicated by arrow L ₁ in the figure), the spacing pitch between the connecting pins 16 and 17 (indicated by arrow L ₂ in the figure), and the spacing between the connecting pins 17 and 18. Pituchi (in the figure, arrow L ₃
) are configured to be equal (L ₁ =L ₂ =L ₃ ).

The shot bar 19 includes a resin case portion 23,
The connecting piece 24 is formed by bending a conductive metal plate, and the connecting piece 24 is connected to the case part 23.
It is installed and fixed in the hole 23a formed in the hole 23a.
Further, curved curled portions 24a and 24b are provided on both sides of the connecting piece 24, and the distance between the center positions of each curled portion 24a and 24b (indicated by arrow _L4 in the figure) is as described above. It is configured to be equal to the spacing pins L ₁ to _{L 3} between the respective connection pins (L ₁ =L ₂ =L ₃ =L ₄ ). Furthermore, each curl portion 24
a and 24b have spring properties, and are configured such that each of the connection pins 15 to 18 can be fitted therein.
Therefore, if you select two connection pins (assuming these two are connection pins 15 and 16) from among each of the connection pins 15 to 18, and attach the short bar 19 to these two connection pins 15 and 16, , each connection pin 1
5 and 16 are short-circuited.

The switching structure 13 having the above-described configuration is incorporated into a density identification circuit 14 as shown in FIG. That is, the connection pin 15 is connected to the inverter 3, the connection pin 16 is connected to the signal identification terminal 6 of the control circuit 5, the connection pin 17 is connected to the interface connector 10, and the connection pin 18 is connected to the density terminal for the host device. It is connected to the switching signal output terminal 26.

Next, a method of connecting the switching structure 13 using the short bar 19 in each case where a magnetic disk device is used in the above-described method or method will be described.

First, the case of the switching method using a medium detection switch provided in the disk device, which is the method described in (2), will be described.

In this case, connect the shot bar 19 to the connecting pin 15,
It will be installed between 16 and 16. As a result, when a magnetic disk is inserted, the switch 2 operates according to the density of the magnetic disk, and a switching signal is supplied to the signal identification terminal 6 of the control circuit 5 (usually called OFP) via the inverter 3. , a density switching signal is output from the output terminal 7 to an amplifier circuit or the like. At this time, as shown in FIG. 3, if another shot bar 25 is simultaneously connected between the remaining two connection pins 17 and 18, the density switching signal output terminal 26 of the control circuit 5 is connected via the interface connector 10. A density identification signal is supplied to the host device, and various processes corresponding to the density are performed on the host device side as well.

Next, a method will be described in which switching is performed using a selection command signal supplied from a host device that is used in combination.

In this case, the shot bar 19 is installed between the connecting pins 16 and 17 as shown in FIG. Thereby, the host device supplies the switching command signal generated by the identification process performed within the device body from the interface connector 10 to the signal identification terminal 6 of the control circuit 5. Since the connection pins 15 and 18 are open, the changeover switches including the switch 2 and the inverter 3 are completely disconnected, and identification of the density of the magnetic disk is controlled by the changeover command signal from the host device.

In the above embodiment, as shown in FIG. 2, the distance between the connecting pins 15 and 18 (
The spacing pitch between other connecting pins (indicated by arrow L ₅ ) is also
Since the structure is the same as that _{of L1} to _L3 , it is possible that the short bar 19 may be attached between the connecting pins 15 and 18, but no problem will occur even if this connection is made.

However, in order to prevent this erroneous connection, the pin headers 20 and 21 are arranged as shown in FIG.
The quadrilateral formed by each of the connecting pins 15 to 18 is configured to be a trapezoid, and the connecting pins 15, 16, 16
and 17, and the spacing pitch between 17 and 18 (in the figure,
arrow L (indicated by ₆ ) and connecting pin 1
Separation pitch between 5 and 18 (indicated by arrow L ₇ in the figure)
may be configured to be larger than L ₆ . As a result, the short bar 19 cannot be connected between the connecting pins 15 and 18, and erroneous connections can be reliably prevented.

Furthermore, in this example, two connection pins were used for one pin header, but
It is not limited to this, but as shown in Figure 6, 4
Of course, the switching structure may be constructed by four pin headers 27 to 30 each having one connection pin 15 to 18 implanted therein.

Effects of the invention As described above, according to the invention, the two methods of density switching can be changed simply by selectively attaching shorting members (short-circuiting bars) to the connection pins, so the operation is simple and simple. It is reliable, and moreover, one magnetic disk device can support the above two methods, the user side can easily change the density after purchase, and the manufacturing side can easily change the density in one system. It has the advantage of being able to be manufactured on a production line of 100, and simplifying the production line.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram showing a density identification circuit incorporating a switching structure which is an embodiment of the present invention, FIG. 2 is an exploded perspective view showing the switching structure in an enlarged manner, and FIG.
The figure is a perspective view showing the connection state of the switching structure in the case of the switching method using the medium detection switch provided in the disk device, and FIG. 4 shows the connection state of the switching structure in the switching method using the selection command signal supplied from the host device. Fig. 5 is a diagram for explaining the arrangement of pin headers that can prevent incorrect connection of the shot bar, and Fig. 6 is a diagram for explaining the arrangement of pin headers that can prevent incorrect connection of the shot bar. A perspective view showing the structure, and FIGS. 7 and 8 are circuit diagrams for explaining a conventional density identification circuit. 2... Switch, 5... Control circuit, 6... Signal identification terminal, 7... Output terminal, 10... Interface connector, 12... Density switching signal input terminal, 13... Switching structure, 14... Density identification circuit, 15-18...Connection pin, 19,2
5... Shoot bar, 20, 21, 27-30...
... Pin header, 23 ... Case part, 24 ... Connection piece, 24a, 24b ... Curl part, 26 ... Density switching signal output terminal.

Claims (1)

[Claims for Utility Model Registration] (1) In order to share magnetic disks with multiple densities (recording densities), switching of circuits etc. installed in the disk device according to the densities of the magnetic disks used A density-compatible circuit switching structure in a magnetic disk device that performs the following: four connecting pins implanted in pin headers and arranged at positions corresponding to respective apex angles of a quadrilateral when viewed from above; A short-circuit member is provided which is selectively connected to two of the four connection pins and makes a short-circuit connection between the two connection pins, and the quadrilateral formed by the pair of connection pins is provided. The spacing pitches of the connecting pins are configured so that the lengths of at least three of the four sides are equal, and the shorting member is located between the positions corresponding to the three sides,
A density-compatible circuit switching structure in a magnetic disk device configured to selectively make three types of short-circuit connections with the connection pin. (2) The density compatible circuit switching structure in a magnetic disk device according to claim 1, wherein the four connection pins are embedded in two pin headers, two each. (3) The density compatible circuit switching structure in a magnetic disk device according to claim 1, wherein the four connection pins are embedded in four pin headers, one each.