JPH04185471A - Driver for drive source - Google Patents

Abstract

PURPOSE:To protect other electronic components from damage by connecting a power supply control means to common power supply side and blocking conduction of the control means when a conduction detecting means detects an abnormality. CONSTITUTION:A power supply voltage Vp and a power supply VD for a control means 1 rise upon turn ON of power and the control means 1 outputs an OFF signal for turning all driving means OFF upon finish of soft initialization. Subsequently, the control means 1 decides whether a conduction detecting means 6 is conducting or not and if the detecting means 6 is conducting, the control means 1 makes a decision of abnormality and turns all driving means 2 OFF or turns at least a power supply control means 5 OFF. If the detecting means 5 is not conducting, the printer proceeds through a series of printing steps and in case of a dot printer, a head trigger coil is conducted according to a position detection signal of the printer thus forming a character.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a drive device, and particularly relates to a drive device for a drive source such as a coil or a motor in the field of information equipment, printers, copy machines, facsimile machines, typewriters, etc. .

[Prior Art] Many electromagnetic active functional parts are used in printers and copiers, and printers include head coils, carriages, paper feed motors, and the like.

Each driving switching element is controlled to be turned on and off by a control means whose main component is a CPU.

FIG. 3 shows a conventional driving device for driving sources such as coils and motors of a printer, etc., in which 11 is a control means whose main part is a CPU, and controls 12 driving means via an interface.

13 is a driving switching element, and 17 is a spark killer diode for protecting the driving switching element. 14
is the printer mechanism, 14A and 14B are the trigger coils,
14C indicates a drive motor.

In the prior art, simply turning on/off the control means 11
The 13 driving switching elements are turned ON1 by the control signal.
The only drive device was to turn on/off the coils and motors of the 14 printer mechanisms.

[Problems to be Solved by the Invention] However, in the above-mentioned drive device, there is a state in which the distance between the collector and the emitter or between the collector and the base is shortened as a breakdown mode of the 13 driving switching elements. , trigger coil 14A, 14.
In B, a current flows from the electric RVp, and as the coil heats up, smoke starts to emit after a period of time, and the coil also causes a layer short, causing the drive transistor 13 and the coils 14A and 14E to emit smoke, catch fire, or cause the coil to emit smoke. There was a problem in that the power supply @ (FPC, etc.) was in a dangerous state that could cause smoke or fire.

The present invention is intended to solve the above-mentioned problems, and its purpose is to prevent damage to other electronic components even if an operator turns on the power without knowing that the driving switching element of the drive source etc. is destroyed. The object of the present invention is to provide a drive device that prevents the above.

[Means for Solving the Problems] To this end, the present invention provides a drive device that drives a drive source by controlling ON/OFF of a drive switching element by a control means, including a power supply control means on a common power source side of the drive source. A conduction detection means for detecting conduction or non-conduction is connected to the driving switching element, and the conduction or non-conduction detection means is inputted to the control means to detect conduction when normally non-conduction. A driving device for a drive source is characterized in that when a control means detects an abnormality, it is determined to be abnormal and at least the power supply control means is not made conductive.

[Operation] With the above-described configuration and means, it is possible to provide a safe device even in the event of damage to the driving switching element that occurs in a printer, particularly in short mode. Therefore, we can provide safe equipment to the market.

[Example] Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows one embodiment of the present invention, and shows a schematic circuit diagram of a printer as an example.

1 is a control means whose main part is a CPU, and in most cases a one-chip microcomputer is used, and CPUIA, R
It consists of AMIB, ROMIC1I10 boat ID, etc.

It receives print commands, data, etc. via an interface section (not shown) and controls the driving means 2 to turn on and off. 3
is a driving switching element, 5 is a power supply control means connected to the common a source Vp side, and 7 is a spark killer diode for protecting the driving switching element.

Reference numeral 4 indicates a printer mechanism section as an example of a device having a drive source, 4A and 4B have trigger coils, and 4C has a drive motor as a drive source.

6 is an embodiment of a conduction/non-conduction detection means, which has a plurality of diodes 6A and is a kind of N of the driving switching element 3.
The cathodes of the diodes 6A are connected to the collector poles of the PN transistors, and the anodes of the diodes 6A are connected in common.

The output of the conduction/non-conduction detection means 6 is input to the control means 1. When the power is turned on, the power supply voltage Vp and control hand Pl
The IE source VD for jl is started up, and the control means 1 performs soft initialization (clears the contents of RAMIB,
10 After setting the boat ID, etc.), turn off all drive means.
Outputs an OFF signal for FF. Thereafter, the control means 1 determines whether the conduction/non-conduction detection means 6 is conductive or non-conductive.
If it is conductive, it is considered abnormal and all drive means 2 are turned to O.
FF. Or at least turn off the power supply control means 5
Let it be. If there is no conduction, the printer goes through a series of printing steps and, in the case of a dot printer, energizes the head trigger coil in response to the printer's position detection signal to form characters. In a type wheel selection type printer, a trigger coil is energized in response to a type wheel position detection signal of the printer to select a type wheel and form characters.

In Fig. 1, an example was explained in which an NPN transistor was used as the driving switching element, but when a PNP transistor is used, the polarity of the diode 6A is reversed, and the anode side of the diode is connected to the collector of the transistor, and the cathode is connected to the collector of the transistor. Similar detection is possible by connecting them in common.

FIG. 2 shows a schematic flowchart of one embodiment according to the invention.

During the soft initialization routine, turn off all drive means.
FF, its trench, conduction/non-conduction detection means determines whether it is conductive or non-conductive, and if it is conductive, it turns off all the drive means or turns off the power supply control means, and then turns on the error display LED, etc. (not shown) causes an error message to be displayed and the printing operation of the printer is stopped. The release is canceled by turning off the power, and the same state repeats even if the IT power is turned on again. In the print routine, if the driving switching element does not have a ○N signal and the conduction/non-continuity detection device is in a conductive state, all the driving means are turned off.
Display an error in the same way.

Although the means for turning on and off the power supply means is shown as a transistor in FIG. 1, a mechanical T-hole can also have the same function.

[Effects of the Invention] As is clear from the above description, the drive device according to the present invention can provide a highly reliable and safe drive without smoke or ignition against destruction of drive switching elements, particularly in short mode, which occurs in printers, etc. Efforts were made to provide equipment. In addition, the operator was notified of a dangerous situation by an error display, and was able to create a situation where repairs could be made before the situation became dangerous.

[Brief explanation of drawings]

FIG. 1 shows one embodiment of the present invention, and is a schematic circuit diagram of a printer as an example. FIG. 2 is a schematic flowchart diagram of one embodiment according to the present invention. FIG. 3 shows a conventional drive device. 1... Control means 3... Drive switching element 4... Drive source 5... Power supply control means 6... Continuity/non-continuity detection means Above Figure 1

Claims (1)

[Claims] 1) The driving switching element is turned ON/OFF by the control means.
In a drive device that drives a drive source under FF control, a power supply control means is connected to a common power source side of the drive source, and a conduction/non-conduction detection means for detecting conduction/non-conduction is connected to the drive switching element. The drive source is characterized in that the conduction/non-conduction detection means is input to a control means, and when the control means detects conduction when normally not conductive, it is determined to be abnormal, and at least the power supply control means is not made conductive. drive unit. 2) In the conduction/non-conduction detection means, the driving switching element is an NPN type transistor, and one end of the driving source and a cathode electrode of a diode are connected to the collector pole in correspondence with the number of the driving switching elements. 2. The drive source drive device according to claim 1, wherein the other ends of the diodes are connected in common. 3) In the conduction/non-conduction detection means, the driving switching element is a PNP transistor, and the collector pole is connected to one end of the driving source and the anode electrode of the diode, respectively, in correspondence to the number of the driving switching elements. 2. The drive source drive device according to claim 1, wherein the diodes are connected together and the other ends of the diodes are commonly connected. 4) The driving device for a drive source according to claim 1, wherein the driving switching of the power supply control means is a semiconductor switching element. 5) The driving device for a drive source according to claim 1, wherein the driving switching element of the power supply control means is a mechanical relay.