JPH04169000A - Driver for stepping motor - Google Patents

Abstract

PURPOSE:To inform a malfunction to an operator while rotating a stepping motor by sending, a malfunction occurs in a device, if any, and driving the motor with the frequency in a resonance frequency band inherent the motor. CONSTITUTION:When a stepping motor 4 is driven to start conveying of a recording medium, a controller 2 monitors the output of a sensor 5, judges whether the medium is conveyed to a predetermined position or not, and waits sensing of the medium, in the case of NO, until a preset predetermined time is elapsed. If the medium cannot sensed within a predetermined time, it is judged that a jam occurs in the device, an inherent frequency drive signal is supplied to the motor 4, and a malfunction is informed to an operator by a resonance sound generated at this time. Thus, the malfunction is informed to the operator while rotating the motor 4.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is applicable to stepping motors in various devices such as printers, FAX machines, PPC copiers, machine tools, sewing machines, and typewriters that use stepping motors as a drive source for suspect members. This invention relates to a motor drive device.

[Conventional technology]

2. Description of the Related Art Conventionally, for example, in a recording device such as a printer, when an abnormality in the recording device is detected, the details of the abnormality are displayed to the operator using an LED display, a liquid crystal display, or the like to notify the operator.

Furthermore, in a recording device connected to a host device such as a personal computer, the detected abnormality is notified to the host device via a signal or communication on an interface.

However, in such recording devices, if the operator does not monitor the device, there will be a delay in discovering abnormalities in the device.For example, in a thermal fixing type recording device, if the fixing unit breaks down, an extremely serious situation may occur. It is possible that you may fall into.

Therefore, it is conceivable to operate a buzzer as a method of notifying the operator of the occurrence of an abnormality by appealing to the auditory senses of the operator, but this will result in an increase in cost.

Furthermore, as seen in Japanese Patent Application Laid-Open No. 1-209997, for example, there is a device in which, when an abnormality occurs in the device, the stepping motor is driven at a frequency other than its response frequency, and the abnormality is notified by the vibration sound generated at that time.

[Problem to be solved by the invention]

However, according to this method, when an abnormality occurs in the device, the stepping motor is unable to rotate, causing step-out, resulting in a misstep.

Under these conditions, abnormal stress is applied to the teeth of gears, pulleys, timing belts, etc. connected to the rotating shaft of the stepping motor, causing secondary failures such as premature tooth wear or timing belt dislocation. is expected.

The present invention has been made in view of the above points, and an object of the present invention is to enable an apparatus having a stepping motor to notify an operator of an abnormality while rotating the stepping motor.

[Means to solve the problem]

In order to achieve the above object, the present invention provides a means for detecting an abnormality occurring in the apparatus in a device having a stepping motor; The present invention provides a stepping motor drive device including means for driving a stepping motor.

Furthermore, it is preferable to provide means for selecting the driving frequency of the stepping motor depending on the type of abnormality occurring in the apparatus and changing the magnitude of the sound generated by the stepping motor.

[For production]

The stepping motor drive device according to the present invention detects when an abnormality occurs in the device and drives the motor at a frequency in the resonant frequency band unique to the stepping motor, thereby generating a unique vibration sound while rotating the stepping motor. to notify the operator of the abnormality.

Furthermore, the volume of the notification sound can be changed depending on the type of abnormality that has occurred.

〔Example〕

Embodiments of the present invention will be specifically described below with reference to the drawings.

FIG. 1 is a block circuit diagram showing an example in which the present invention is applied to a recording device as an embodiment.

In this figure, 1 is a controller that controls the recording device, and 2 is a stepping motor control section (hereinafter simply referred to as "control section") using a microcomputer disposed inside the main body of the recording device. It has a CPU that executes the processing procedures shown, a ROM that stores programs, etc. corresponding to the processing procedures, and a RAM for work.

3 is a stepping motor drive circuit, and 4 is, for example, a four-phase stepping motor, which is used as an active source for conveying the recording medium in this embodiment.

5 is a sensor that detects the recording medium being conveyed, and 7 is L that visually reports abnormality in conveyance (jam) of the recording medium.
It is ED.

FIG. 2 is a flowchart showing an example of a processing procedure executed by the stepping motor control section 2. As shown in FIG.

When the recording device is ready for printing, first the control unit 2
sends printer ready signal RE to external controller 1.
Turn on ADY. External controller 1
When the controller 2 turns on the print signal PRINT to the control section 2, the control section 2 outputs a stepping motor excitation signal to the drive circuit 3 of the stepping motor 4 in order to carry out a recording medium transport operation for printing.

In this embodiment, since the stepping motor 4 has four phases, the excitation signal also has four phases (i'h+ /AT Bl/B).
Output.

When the stepping motor 4 is driven to start conveying the recording medium, the control section 2 monitors the output of the sensor 5 and determines whether the recording medium has been conveyed to a predetermined position.

If YES here, stepping motor drive circuit 3
Normal recording motion during printing is performed on the stepping motor 4 via the stepper motor 4.

In the case of No, detection of the recording medium is waited until a preset predetermined time has elapsed.

If the recording medium cannot be detected within a predetermined time, it is determined that a jam has occurred within the machine, and appropriate notification processing is performed at this point.

That is, the LED 7 is made to blink via the resistor R, and the printer ready signal R is sent to the external controller 1.
This is a process of notifying the operator or host device of the occurrence of a jam by turning off EADY.

Next, the control unit 2 generates an excitation signal (A, /A) at a frequency in the resonant frequency band of the stepping motor 4.

B, /B) on/off.

FIG. 3 shows an example of the relationship between the driving frequency of the stepping motor 4 and the rotation speed fluctuation rate.

Here, f2 has the largest rotational speed fluctuation rate and is called a resonance point. Further, approximately f1 to f4 is referred to as a resonance band. Normal rotational driving is performed at a driving frequency of f5 or higher, avoiding this resonance band.

As shown in FIG. 4, at the resonance point f2, the resonance generated by the motor is the largest, and the resonance sound is also the largest. Below, f3. f4. Continues in the order of fl.

That is, in the above-mentioned process, a vibration signal of frequency f2 is supplied to the stepping motor 4, and the abnormality can be notified to the operator by the resonance sound generated at this time. This abnormality notification can be performed until, for example, the cause of the abnormality is removed or the device is reset.

Note that abnormal conditions other than jams may occur in the recording device. For example, in a laser beam printer, there is an abnormality in the polygon motor or the laser beam generator, and in a thermal fixing type recording apparatus, there is an abnormality in the fixing motor.

In a recording device where various abnormalities occur, the type of abnormality can be notified by selecting a drive frequency depending on the abnormality mode and changing the magnitude of the sound generated by the stepping motor.

For example, if the drive frequency f2 shown in FIG.
f3 can be set to the time when the polygon motor is abnormal, and fl can be set to the time when the laser beam generator is abnormal.

Furthermore, even if the stepping motor is driven intermittently at a constant cycle and the cycle is changed depending on the abnormal mode, or the ratio of the recording time to the stop time is changed according to the abnormal mode, The type can also be reported.

Furthermore, although the above embodiment describes the case where the present invention is applied to a recording device, any device that uses a stepping motor as an active source for some driven member can report one or more abnormalities regardless of its type. Of course, it is extremely effective for this purpose and can be applied to containers.

For example, in an image reading device, a stepping motor is sometimes used as an active source for conveying a document or as a moving source for scanning a reading head, and the present invention is also effective for such devices. It is.

〔Effect of the invention〕

As explained above, according to the present invention.

When an abnormality occurs in a device that has a stepping motor, it is possible to issue an audible warning to the operator by simply rotating the stepping motor at a frequency within the resonant frequency band, without increasing the cost of the device. The excellent effect of prompting prompt treatment can be obtained.

Furthermore, there is no fear that secondary failures will occur due to step-out of the stepping motor.

[Brief explanation of the drawing]

Fig. 1 is a block circuit diagram of a recording device showing an embodiment of the present invention, Fig. 2 is a flowchart showing the processing procedure by the stepping motor control section, and Fig. 3 shows the driving frequency and rotational speed fluctuation rate of the stepping motor. FIG. 4 is a diagram showing an example of the relationship between the driving frequency of the stepping motor and the vibration level. 1... Controller 2... Stepping motor control section 3... Stepping motor glare circuit 4... Stepping motor 5... Sensor 7... LED Figure 2

Claims (1)

[Scope of Claims] 1. In an apparatus having a stepping motor, means for detecting an abnormality occurring in the apparatus; and when the means detects an abnormality, the stepping motor is activated at a frequency in a resonant frequency band of the stepping motor. A stepping motor drive device comprising: means for driving a stepping motor; 2. The stepping motor drive device according to claim 1, further comprising means for selecting the driving frequency of the stepping motor depending on the type of abnormality occurring in the device and changing the magnitude of the sound generated by the stepping motor. A stepping motor drive device featuring: