JPH07280889A - Method of voltage margin test for device - Google Patents

Abstract

PURPOSE:To obtain a voltage margin test method for device in which the man- hour of tester can be reduced at the time of voltage margin test in the production process of a device. CONSTITUTION:A device to be tested comprises a test switch 26, a section 27 for setting the DC output voltage from a power supply section 3 at any one of upper limit, lower limit or a prescribed level, a circuit section 31 for modifying the output voltage from the power supply section 31 according to a voltage command being set, and a test program stored in a memory section 22. When the test switch 26 is turned ON (S51), a control section 21 in the device modifies the DC output voltage from the power supply section 3 in the order of a prescribed value S52, a lower limit S54, and an upper limit S56 based on the test program and test operations S53, S55, S57 are performed automatically at respective voltages.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a voltage margin test method in the manufacturing process of various devices such as OA (office automation) devices and financial automation devices.

[0002]

2. Description of the Related Art Conventionally, as one of the quality assurance tests in the manufacturing process of electronic devices using, for example, semiconductors and ICs, the power supply voltage for operating the device is changed from a specified voltage up and down within a specified range so that Generally, a voltage margin test for confirming normal operation is performed.

Generally, the power supply unit in the apparatus inputs AC power, outputs DC voltage and supplies it to each section in the apparatus. Normally, the DC voltage output by manual adjustment of the output voltage adjusting volume. Is variable. Further, the apparatus usually has a built-in test switch, and when the switch is turned on, the apparatus is put into a test mode and, for example, when the apparatus is a printer, a test operation for printing various preprogrammed patterns can be performed. it can.

The voltage margin test of the conventional device is performed in the following order. (1) First, adjust the output voltage adjusting volume of the power supply unit, set the DC voltage to be output to the specified voltage value, turn on the test switch, perform the specified test operation, and confirm that normal operation is performed. , Then turn off the test switch. (2) Next, the output voltage adjusting volume of the power supply unit is adjusted to set the output DC voltage to the specified upper limit value (for example, 10% increase of the specified voltage value), and the test switch is turned on again to perform the test operation. After checking the operation, turn off the test switch. (3) Further, the output voltage adjusting volume of the power supply unit is adjusted, the output DC voltage is set to the specified lower limit value (for example, 10% of the specified voltage value is decreased), the test switch is turned on again, and the test operation is performed. After checking the operation, turn off the test switch. (4) Finally, the output voltage adjusting volume of the power supply unit is readjusted to return the output DC voltage to the specified voltage value.

[0005]

However, in the voltage margin test of the device as described above, the DC voltage value is adjusted by the manual operation of the tester, so that the man-hour of the tester becomes large and the cost in the manufacturing process of the device becomes large. There was a problem that it would increase.

[0006]

According to a method of testing a voltage margin of an apparatus according to the present invention, the apparatus has a built-in power source section for supplying a DC power source to each section in the apparatus, and defines a DC voltage output by the power source section. In a device voltage margin test method for confirming that the device normally operates by changing from a voltage value to an upper limit value and a lower limit value, a test switch for starting a voltage margin test in the device to be tested. A voltage change setting unit in which the control unit of the device can individually set ON / OFF of a voltage upper limit command and a voltage lower limit command,
A DC voltage variable circuit that changes the output voltage of the power supply unit to an upper limit value, a lower limit value, or a specified voltage based on turning on or off of the voltage upper limit value command or the voltage lower limit value command set in the voltage change setting unit Section and a test program stored in the memory section, and when a voltage margin test is started by the test switch, the control section of the device, based on the stored test program, outputs a voltage upper limit command and a voltage. Controlling the on / off of a lower limit value command to change the output voltage of the power supply unit to an upper limit value, a lower limit value or a specified voltage, and automatically performing a test operation of the device at each of the changed voltages. I have.

[0007]

In the present invention, a test switch for starting a voltage margin test is provided in advance in a device to be tested, and a control unit of the device turns on / off a voltage upper limit command and a voltage lower limit command, respectively. The output voltage of the power supply unit is set to the upper limit value or the lower limit value based on the voltage change setting unit that can be set individually and the voltage upper limit command or the voltage lower limit command set in the voltage change setting unit, or both are turned off. Alternatively, in the step of performing a voltage margin test of the device by providing a DC voltage variable circuit section for changing to a specified voltage and a test program stored in the memory section, when the voltage margin test is started by the test switch, Based on the stored test program, the control unit of the device turns on the voltage upper limit value command and the voltage lower limit value command.
The output voltage of the power supply is changed to the upper limit value, the lower limit value, or the specified voltage by controlling the OFF, and the test operation of the device is automatically performed at each of the changed voltages. Man-hours at the margin test are significantly reduced.

[0008]

FIG. 2 is a block diagram showing a configuration example of an apparatus according to the present invention, and in this example, a printer apparatus is shown as the apparatus. In FIG. 1, reference numeral 1 denotes the entire printer device, 2 denotes a printer control unit, and a μCPU 21 for controlling the printer control unit 2, a memory unit 22, an interface unit 23 with a higher-level device, a control circuit unit 24, a mechanism drive circuit are provided inside. The unit 25, the test switch 26, and the voltage change setting unit 27 are included. Reference numeral 3 denotes a power supply unit that receives an AC power supply, outputs a DC voltage and supplies the DC voltage to the printer control unit 2, and includes a DC voltage variable circuit unit 31 inside.

The memory section 22 stores a test program (TP) for confirming the operation of the apparatus, in addition to an application program (AP) operated when an end user uses the apparatus, and a test switch 26.
The operation mode of TP / AP is switched by turning on / off of.

The voltage change setting unit 27 includes a register in which ON / OFF of the voltage upper limit command and the voltage lower limit command is individually set under the control of the μCPU 21, and the output of this register is the voltage upper limit command and the voltage upper limit command. The voltage lower limit value command is supplied to the DC voltage variable circuit unit 31 in the power supply unit 3.

FIG. 3 is a detailed block diagram of the power supply unit shown in FIG. 2, showing an example of the power supply unit using a switching regulator. Reference numeral 31 in FIG. 2 denotes a DC voltage variable circuit section, which includes resistors R1 to R4 connected in series between the output terminal of the power supply section and the ground terminal, and analog switches ASW1 and AS.
It is composed of W2. Also analog switch ASW
The ON / OFF signals of the voltage lower limit value command and the voltage upper limit value command from the voltage change setting unit 27 are respectively supplied as signals for individually controlling ON / OFF of 1 and ASW2.
32 is a rectification unit, 33 is a switching unit, 34 is a voltage control unit, 35 is a voltage conversion unit, and 36 is a DC output unit.

In the power supply unit 3 constructed as described above, when both the analog switches ASW1 and ASW2 are off, the output voltage of the DC output unit 26 is Vout,
When the feedback voltage from the connection point of the resistors R2 and R3 to the voltage control unit 34 is Vf, Vf is expressed by the following equation (1). Vf = (R3 + R4) · Vout / (R1 + R2 + R3 + R4) (1) Then, when Vf represented by the equation (1) is input to the voltage control unit 34, the output voltage Vout is controlled to have a specified voltage value. .

Next, when the voltage lower limit command is on and the analog switch ASW1 is on, the voltage upper limit command is off and the analog switch ASW2 is off, the feedback voltage Vf is expressed by the following equation (2). Vf = (R3 + R4) .Vout / (R1 + R3 + R4) (2) Then, when Vf represented by the equation (2) is input to the voltage control unit 34, the output voltage Vout is defined as a lower limit voltage value (for example, a standard voltage value). Resistance R
The values of 1, R3 and R4 are determined.

Next, when the voltage lower limit value command is turned off, the analog switch ASW1 is turned off, the voltage upper limit value command is turned on, and the analog switch ASW2 is turned on, the feedback voltage Vf is expressed by the following equation (3). Vf = R4 · Vout / (R1 + R2 + R4) (3) Then, when Vf represented by the equation (3) is input to the voltage control unit 34, the output voltage Vout is regulated to the upper limit voltage (for example, 10 of the standard voltage value). % Increase) so that the resistance R
The values of 1, R2 and R4 are determined.

The above is summarized as follows. ASW1, ASW2, Output voltage (Vout) Off Off Specified voltage value On Off Lower limit voltage value Off On Upper limit voltage value

FIG. 1 is a flow chart showing the sequence of a voltage margin test method for a device according to the present invention. The operation of FIG. 2 will be described with reference to FIG. First, the μCPU 21 determines whether the test switch 26 is on or off (S51).
Commands from the host device via the interface unit 23,
The AP mode operation is performed based on the application program (AP) read from the memory unit 22 (S6).
0), and returns to S51 after the end. Also, test switch 26
If is ON, the μCPU 21 immediately turns off both the voltage lower limit command and the voltage upper limit command as a test with the specified voltage value based on the test program (TP) read from the memory unit 22 (S52), and operates in the test mode. Is performed (S53). In this example, since the device to be tested is the printer device, the test mode operation is usually a printing operation of various patterns programmed in advance. Then, the tester checks whether or not the test mode operation is normal.

Next, as a test based on the lower limit voltage value, the voltage lower limit value command is turned on and the voltage upper limit value command is turned off (S5
4) Similarly, the test mode operation is performed (S55), and the result is checked by the examiner. Further, as a test using the upper limit voltage value, the voltage lower limit value command is turned off, the voltage upper limit value command is turned off (S56), the test mode operation is similarly performed (S57), and the result is also checked. Finally, both the voltage lower limit value command and the voltage upper limit value command are turned off (S58), the voltage is returned to the specified voltage, and then the process returns to S51.

In the above embodiment, the example of the printer device was shown as the device to be tested, but the present invention is not limited to this, and the device has a built-in power supply unit, and the power supply unit is inside the device. The present invention can be applied to any device as long as a DC power is supplied to each part. In the above embodiment, the upper and lower limits of the DC voltage output by the power supply unit are increased by 10% and 10% of the specified voltage value, respectively.
Although an example in which the percentage is reduced is shown, the present invention is not limited to this. For example, recently + 5V power supply is +2.5
There are ICs and LSIs on the market that can operate even when the voltage drops to about V. In such a case, the lower limit value should be set to a desired value (for example, 50% reduction of the specified voltage value). Good.

[0019]

As described above, according to the present invention, the device has a power supply part for supplying a DC power supply to each part in the device, and the DC voltage output by the power supply part is set from the specified voltage value to the upper limit value. In a device voltage margin test method for confirming that the device normally operates by changing to a lower limit value, a test switch for starting a voltage margin test in a device to be tested, and a control unit of the device. Is a voltage change setting unit that can individually set ON / OFF of the voltage upper limit command and the voltage lower limit command, and ON or OFF of the voltage upper limit command or the voltage lower limit command set in the voltage change setting unit. On the basis of the above, the output voltage of the power supply unit is changed to an upper limit value, a lower limit value, or a specified voltage, and a DC voltage variable circuit unit and a test program stored in the memory unit are provided, and the test When the voltage margin test is started by the switch, the control unit of the apparatus controls the output voltage of the power supply unit by controlling the ON / OFF of the voltage upper limit value command and the voltage lower limit value command based on the stored test program. By changing to the upper limit value, the lower limit value or the specified voltage and automatically performing the test operation of the device at each of the changed voltages, it is possible to reduce the man-hours of the tester during the voltage margin test of the device. The cost in the manufacturing process can be reduced.

[Brief description of drawings]

FIG. 1 is a flow chart showing the sequence of a voltage margin test method for a device according to the present invention.

FIG. 2 is a block diagram showing a configuration example of an apparatus according to the present invention.

FIG. 3 is a detailed block diagram of the power supply unit of FIG.

[Explanation of symbols]

 1 Printer device 2 Printer control part 3 Power supply part 21 μCPU 22 Memory part 23 Interface part 24 Control circuit part 25 Mechanism drive circuit part 26 Test switch 27 Voltage change setting part 31 DC voltage variable circuit part

Claims (3)

[Claims] 1. A device has a power supply unit for supplying a DC power supply to each unit in the device, and the DC voltage output by the power supply unit is changed from a specified voltage value to an upper limit value and a lower limit value so that the device operates normally. In a device voltage margin test method for confirming operation, a test switch for starting a voltage margin test in a device to be tested, and a control unit of the device have a voltage upper limit command and a voltage lower limit command. Output voltage of the power supply unit based on the voltage change setting unit that can individually set ON / OFF of the power supply and the ON or OFF of the voltage upper limit command or the voltage lower limit command set in the voltage change setting unit. , A DC voltage variable circuit section for changing the upper limit value, the lower limit value, or a specified voltage, and a test program stored in the memory section. Is started, the control unit of the device controls ON / OFF of the voltage upper limit command and the voltage lower limit command based on the stored test program to control the output voltage of the power supply unit to the upper limit value or the lower limit value. Alternatively, the method includes a step of changing to a specified voltage and automatically performing a test operation of the apparatus at each of the changed voltages. 2. The DC voltage variable circuit section includes a plurality of DC voltage variable circuit sections connected between an output terminal and a ground terminal of the power source section in response to ON / OFF of the voltage upper limit value command and the voltage lower limit value command. 2. The voltage margin test method for an apparatus according to claim 1, further comprising a pair of analog switches that short-circuit or open a part of the series resistors. 3. An upper limit value and a lower limit value of the DC voltage output by the power supply unit for performing the voltage margin test of the device are set to 10% increase and 10% decrease of the specified voltage value, respectively. A voltage margin test method for the device according to claim 1.