JP4930861B2 - Image forming apparatus - Google Patents

Description

The present invention relates to an image forming apparatus provided with a hard disk drive .

In an image forming apparatus provided with a hard disk drive, when the power is cut off during data transfer to the hard disk drive, the data stored in the buffer memory 132 in the hard disk drive 13 is stored after the data transfer to the hard disk drive is completed. It is stored in the hard disk drive 130. For this reason, when there is no time for storing data in the hard disk drive 130, the data is destroyed.

Therefore, in the invention of Patent Document 1 below, a power interruption is detected on the electronic device side, and when this detection is performed, data transfer to the hard disk drive is stopped.
JP 2006-318105 A

  However, even if the data to be transferred to the hard disk drive can be prevented from being destroyed, it may not be possible to prevent the magnetic head slightly floating from the disk surface from contacting the magnetic disk surface and crashing the head. .

In view of such problems, an object of the present invention is to provide an image forming apparatus capable of preventing a head crash in a hard disk drive even if the power is cut off during data transfer to the hard disk drive. It is in.

In a first aspect of the image forming apparatus according to the present invention, a hard disk drive having a controller, said controller, in the image forming apparatus to move the magnetic head to the retracted position in response to a reset command supplied,
A power-off detection circuit that detects that the power-supply voltage has fallen below the threshold and activates a power-off signal;
Control means for supplying a reset command to the hard disk drive in response to activation of the power-off signal.

According to a second aspect of the image forming apparatus of the present invention, in the first aspect, a drive mechanism that drives a mechanical component, and a system control unit that includes a computer and supplies a control signal to the drive mechanism and accesses the hard disk drive. A power supply circuit for the drive mechanism and the system control unit, and the power supply voltage is supplied from the power supply circuit to the drive mechanism.

  According to the configuration of the first aspect, since the reset command is supplied to the hard disk drive and the magnetic head moves to the retracted position when the power supply voltage falls below the threshold value, it is possible to prevent head crashes in the hard disk drive. The effect of becoming.

  According to the configuration of the second aspect, the reset command is supplied to the hard disk drive in response to the detection that the voltage supplied from the power supply circuit to the mechanical component drive mechanism has become the threshold value or less. Is performed, and the head crash can be prevented more reliably.

  Other objects, configurations and effects of the present invention will become apparent from the following description.

Figure 1 is a schematic functional block diagram of the images forming apparatus 10.

  The image forming apparatus 10 supplies a power supply voltage to the system controller 11, the print engine 12 and the hard disk drive 13 that perform detailed control internally based on the outline control thereby, and the system controller 11, the print engine 12, and the hard disk drive 13. The power supply circuit 14 is provided.

  The power supply circuit 14 steps down, rectifies and smoothes the supplied 100V commercial AC power supply to generate DC voltages of 5V and 12V. A power supply voltage VL of 5V is supplied to the system controller 11, the print engine 12 and the hard disk drive 13, and a power supply voltage VH of 12V is supplied to the print engine 12 and the hard disk drive 13.

  The mechanical drive unit of the print engine 12 uses a voltage of 12V, consumes a relatively large amount of power, and the voltage stabilization level by the capacitor is lower than that of the system controller 11, so as shown in FIG. In addition, the voltage VH drops to 0 V earlier than VL when the power is shut off.

  Therefore, in order to detect the power interruption early, the power interruption detection circuit 120 is provided in the print engine 12, and it is determined whether or not the voltage VH supplied to the mechanical drive unit in the print engine 12 is equal to or lower than the threshold value V1th. This is detected by the power interruption detection circuit 120. When this detection is performed, as shown in FIG. 3B, the power-off detection signal S is activated (a flip-flop is set), which is supplied to the HDD reset control unit 110 in the system controller 11, and the HDD The reset control unit 110 deactivates the power-off detection circuit 120 (this flip-flop is reset).

  On the other hand, the hard disk drive 13 includes a hard disk drive 130 in which data is recorded, a drive mechanism 131 that drives an arm with a magnetic head, and a buffer memory in which data supplied from the system controller 11 via the data bus DB is temporarily stored. 132 and a hard disk controller 133 that controls the drive mechanism 131 and the buffer memory 132 while transmitting and receiving data and commands to and from the system controller 11. This command is supplied via the control bus CB.

  The HDD reset control unit 110 includes hardware and software of a one-chip microcomputer. The power-off detection signal S is supplied to the HDD reset control unit 110 as a CPU interrupt signal.

  FIG. 2 is a schematic flowchart showing a software configuration of the HDD reset control unit 110. This process is started by a CPU interrupt. Hereinafter, the parenthesized characters are step identification codes in FIG.

  (S0) The CPU interrupt includes interrupts other than the power shutdown, and the cause of the interrupt is examined based on the contents written in the status register at the time of the interrupt.

  (S1) If it is determined that the cause of the interruption is due to the activation of the power-off detection signal S from the power-off detection circuit 120, the process proceeds to step S2, and if not, the process proceeds to step S3.

  (S2) A reset command RCMD is transmitted to the hard disk controller 133 via the control bus CB.

  In response to this, the hard disk controller 133 writes the contents of the buffer memory 132 to the hard disk drive 130 via the drive mechanism 131, and then moves the magnetic head from the accessed track position to the retracted position. This process is performed during Δt in which the voltage VL decreases to the threshold value V2th in FIG. Δt depends on the configuration of the power supply circuit 14 and its load, and is about several ms to several tens of ms.

  (S3) Other processing according to the interrupt cause is performed.

  According to the first embodiment, when the power supply voltage VH becomes equal to or lower than the threshold value V1th, the reset command RCMD is supplied to the hard disk drive 13 and the magnetic head moves to the retracted position, thereby preventing head crashes in the hard disk drive. There is an effect that becomes possible.

  Further, since the reset command is supplied to the hard disk drive in response to the detection that the power supply voltage VH supplied from the power supply circuit 14 to the mechanical component drive mechanism in the print engine 12 has become equal to or lower than the threshold value V1th, the above-described operation is promptly performed. There is an effect that it is possible to prevent the head crash more reliably by the movement.

  Note that the present invention includes various other modifications.

  For example, in the above embodiment, the case where the electronic apparatus is the image forming apparatus 10 has been described. However, the present invention is not limited to this, and preferably, the power supply voltage to the drive mechanism that drives the mechanical component is equal to or lower than the threshold value. Any electronic device may be used provided with a power-off detection circuit for detecting this and a control means for supplying a reset command to the hard disk drive in response to this detection.

It is a schematic functional block diagram of the images forming apparatus. 2 is a schematic flowchart showing a software configuration of an HDD reset control unit in FIG. 1. (A) is a voltage waveform diagram showing changes in power supply voltages VH and VL at the time of power shutdown, (B) is a power failure detection signal waveform diagram, (C) is a reset command transmission timing chart, D) is an explanatory diagram of a change in position of the magnetic head.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Image forming apparatus 11 System controller 110 HDD reset control part 12 Print engine 120 Power failure detection circuit 13 Hard disk drive 130 Hard disk drive 131 Drive mechanism 132 Buffer memory 133 Hard disk controller 14 Power supply circuit DB Data bus CB Control bus S Power failure detection signal VH , VL voltage

Claims (1)

A hard disk drive having a controller for moving the magnetic head to the retracted position in response to a reset command supplied;
A print engine including a mechanical drive;
A system controller having a computer for supplying control signals to the print engine and accessing the hard disk drive;
A power supply circuit for supplying a power supply voltage to the hard disk drive, the print engine, and the system controller;
In an image forming apparatus having
A power-off detection circuit that is provided in the print engine and detects that a power-supply voltage supplied from the power-supply circuit to the print engine is equal to or lower than a threshold and activates a power-off signal;
The system control unit performs an interrupt process for supplying a reset command to the hard disk drive in response to an interrupt due to activation of the power-off signal.
An image forming apparatus.