JP4165037B2 - Portable reader - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a portable reader having an impact detection function.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, for example, a portable reader device operates by being supplied with power from a built-in battery.
[0003]
[Problems to be solved by the invention]
By the way, this type of portable reader device is often inadvertently dropped because the user reads the code or ID tag while holding it with one hand. In such a case, since a large impact is applied to the electronic circuit constituting the portable reader, there is a risk that the electronic circuit may break down due to the accumulation of the falling impact. Therefore, when a large impact is applied to the portable reader, it is necessary to detect this and call attention to the user.
[0004]
However, it is necessary to provide an expensive sensor such as an acceleration sensor or an impact sensor to detect that a large impact is applied to the portable reader, and the cost is significantly increased.
The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a portable reader capable of detecting that an impact has been applied with a simple configuration.
[0005]
[Means for Solving the Problems]
According to the invention of claim 1, when the user accidentally drops the portable reader device, the main battery is provided so that a large impact is applied to the portable reader device and power is supplied in contact with the contacts. It comes off momentarily. Then, the power supply voltage from the main battery is lowered to a predetermined level or lower, and this is detected by the voltage down detection means. Therefore, the determination means monitors the voltage measured by the power supply voltage measurement means for a predetermined time. When the measured voltage is lowered again below the predetermined level, it is determined that an impact is applied. Thereby, it is possible to detect that an impact has been applied with a simple configuration.
[0006]
According to the invention of claim 2, the read data is stored in the volatile storage means. Since this volatile storage means is backed up by a secondary battery, the read data can be stored for a long period of time.
[0007]
Here, since the operation becomes impossible when the power supply voltage from the main battery is lowered below a predetermined level, the switching unit switches the power source from the main battery to the sub battery. Thereby, the reading operation by the portable reading device can be continued. In this case, the secondary battery is provided to back up the volatile storage means, and since its capacity is small, when the secondary battery is used as a power source for a long period of time, the secondary battery is consumed in a short time. The volatile storage means cannot be backed up.
Therefore, the switching means returns from the secondary battery to the main battery when the judgment means judges that the impact is applied, so that the secondary battery can be prevented from being used as a power source for a long time.
[0008]
In addition, when the main battery is removed, for example, for battery replacement, the state where the power supply voltage from the main battery is below a predetermined level continues. In such a case, the determination means determines that the battery is disconnected. At this time, since the switching unit stops power feeding by the sub battery when the determination unit determines that the battery is disconnected, the sub battery can be prevented from being used as a power source for a long time.
[0009]
According to the invention of claim 3, when the voltage down detecting means detects that the power supply voltage is down, the power supply stopping means stops the power supply from the power source to the predetermined electronic circuit. By stopping the operation, the consumption of the sub battery can be reduced.
[0010]
According to the invention of claim 4, since the predetermined electronic circuit is a high load circuit, the consumption of the sub battery can be greatly reduced.
[0011]
According to the fifth to seventh aspects of the present invention, the volatile storage means stores the information related to the impact in the storage means when the determination means determines that the impact is applied, so the information related to the impact stored in the volatile storage means. Based on the above, it is possible to estimate the influence of the impact on the electronic circuit.
[0012]
According to the invention of claim 8, since the abnormality notification means notifies the abnormality when the determination means determines that the impact is applied, the user applies a large impact to the portable reading device by the abnormality notification by the abnormality notification means. I can see that I did it.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment in which the present invention is applied to a handy type barcode reader will be described with reference to the drawings.
FIG. 2 is a sectional view of a handy type barcode reader. In FIG. 2, the bar code reader 1 is mainly composed of a hand-held case 2, and the case 2 is provided with a keyboard 3, a liquid crystal display unit (corresponding to abnormality notification means) 4, and the like. A printed wiring board 5 is disposed in the case 2, the keyboard 3 and the liquid crystal display unit 4 are provided on one surface of the printed wiring board 5, and an optical sensor is provided on the other surface. A CCD line sensor 6 and an imaging lens 7 are provided, and a secondary battery 8 made of a coin-type lithium battery is fixedly mounted.
[0014]
The front opening of the case 2 is a reading port 9, and the printed wiring board 10 disposed in the case 2 so as to be positioned near the reading port 9 is surrounded by a hole 10 a formed at the center thereof. A plurality of illumination LEDs 11 serving as illumination means and an illumination lens 12 facing the illumination LEDs 11 are provided. In the case 2, a reflection mirror 13 is provided between the reading port 9 and the imaging lens 7. In addition, a display window 15 made of a long hole closed by the translucent plate 14 is provided on the upper surface of the case 2 near the reading port 9. Corresponding to the display window 15, the printed wiring board 10 is provided with a notification LED 16 as notification means.
[0015]
FIG. 3 shows the battery mounting portion provided on the back surface of the case 2 with the cover not mounted. In FIG. 3, a concave battery mounting portion 17 is formed on the back surface of the case 2, and a main battery 18 made of a dry cell is mounted on the battery mounting portion 17. In the main battery 18, the positive electrode is in conductive contact with a leaf spring 19 that is a positive contact, and the negative electrode is in conductive contact with a spring spring 20 that is a negative contact in a biased state.
[0016]
FIG. 1 is a block diagram showing an electrical configuration of the barcode reader 1. In FIG. 1, a main battery 18 is connected to a switching element (corresponding to switching means) 21 and is connected to a sub battery 8 via a DC / DC conversion circuit 22. The sub battery 8 is also a switching element. 21 is connected. The sub-battery 8 is a secondary battery that can be charged from the main battery 18, and supplies power so as to back up a DRAM (corresponding to volatile storage means) 23 (not shown).
[0017]
The switching element 21 is connected to the DC / DC conversion circuit 25 using either the main battery 18 or the sub battery 8 as a power source in response to a command from a CPU (corresponding to a voltage down detection unit, a power supply voltage measurement unit, and a determination unit) 24. Or block the connection. A smoothing capacitor 26 is connected to the input terminal of the DC / DC conversion circuit 25 to stabilize the DC voltage input to the DC / DC conversion circuit 25.
[0018]
In addition to the power supply terminal of the CPU 24, the output terminal of the DC / DC conversion circuit 25 is connected to a clock IC 27, a confirmation unit 28 including a buzzer and an LED, a power supply terminal of the liquid crystal display unit 4, and a gate element 29. . The gate element 29 is a high-load electronic circuit such as a reading unit 30, a DRAM 30, a FROM 31, a keyboard 3, and a communication unit 32 including the CCD line sensor 6 and the illumination LED 11 from the DC / DC conversion circuit 25 according to a command from the CPU 24. The power supply to is stopped.
[0019]
Here, the analog input terminal of the CPU 24 is connected to the power supply line 33 connected to the leaf spring 19 that is in conductive contact with the main battery 18 so that the voltage of the power supply line 33 can be input. In this case, the power supply line 33 is also connected to the interrupt terminal of the CPU 24, and an interrupt command is sent to the CPU 24 when the voltage of the power supply line 33 is lowered to a predetermined threshold level or lower (see FIG. 5A). Is to be given.
[0020]
Next, the operation of the above configuration will be described.
For example, when the user reads a barcode printed on a label attached to a product, the user reads the barcode 3 on the keyboard 3 while pressing the reading port 9 of the barcode reader 1 against the label on which the barcode is printed. Manipulate. Then, the illumination LED 11 is turned on and the barcode is illuminated, so that the barcode is imaged on the CCD line sensor 6 by the imaging lens 7. Then, the CPU 24 decodes information indicated by the barcode based on the image signal output from the CCD line sensor 6 and stores it in the DRAM 23.
[0021]
When transmitting the information read as described above to the management device, the transmission is performed with the barcode reader 1 set in the communication device or connected to the management device. Then, the CPU 24 transmits the information stored in the DRAM 23 to the management device through the communication unit 32, so that the management device can collectively manage the products based on the information read by the barcode reader.
[0022]
By the way, when a user reads a barcode with the barcode reader 1, the barcode reader 1 may be accidentally dropped because it is operated while holding the barcode reader 1 with one hand. When the barcode reader 1 is dropped as described above, a large impact is applied to the electronic circuit that constitutes the barcode reader 1, and thus the electronic circuit that constitutes the barcode reader 1 may be damaged due to the impact of the fall. There is.
[0023]
Therefore, in the present embodiment, it is detected that a large impact has been applied to the barcode reader 1 as follows, and this is notified to the user.
That is, when the barcode reader 1 falls and a large impact is applied, the large impact is also applied to the main battery 18. At this time, since the positive electrode of the main battery 18 is only in conductive contact with the plate spring 19 which is a positive contact, when a large impact is applied to the barcode reader 1, the positive electrode of the main battery 18 is The spring 19 may be separated.
[0024]
In such a case, the voltage of the power supply line 33 connected to the main battery 18 is lowered to a predetermined threshold level or less at the timing when the positive electrode of the main battery 18 is detached from the leaf spring 19, so that an interrupt command is issued to the CPU 24. Given. As a result, the CPU 24 shifts from a main program (not shown) to an interrupt program.
[0025]
FIG. 4 is a flowchart showing the interrupt program of the CPU 24. In FIG. 4, the CPU 24 first executes prohibition of interrupt (S101). As a result, even if the voltage of the power supply line 33 falls below a predetermined threshold level again during execution of this interrupt program, the interrupt program can be prevented from being interrupted.
[0026]
Subsequently, the CPU 24 switches the power source from the main battery 18 to the sub battery 8 by switching the switching element 21 (S102). Thereby, since the sub battery 8 is connected to the CPU 24, the CPU 24 can continuously operate by the power supply from the sub battery 8.
When the power source is switched from the main battery 18 to the sub-battery 8, the power supply to the CPU 24 is momentarily cut off, but in that case, the power is supplied from the smoothing capacitor 26, so the CPU 24 can maintain the operating state. .
[0027]
Subsequently, the CPU 24 stops power supply to the reading unit 30, the FROM 31, the keyboard 32, and the communication unit 32, which are high load circuits, by turning off the gate element 29 (S103). As a result, only the clock IC 27, the confirmation unit 28, and the liquid crystal display unit 4 can be fed from the sub battery 8, and the consumption of the sub battery 8 can be greatly reduced.
[0028]
Subsequently, after the contents stored in the DRAM 23 are saved in the FROM 31 (S104), the voltage of the power supply line 33 is monitored for a predetermined time (S105). In this case, the power supply voltage when the main battery 18 is removed due to an impact is repeatedly lowered a plurality of times as shown in FIG. 5 (a) in the case of a large impact, so that the CPU 24 is shown in FIG. When such a change in power supply voltage is detected, it is determined that an impact has been detected (S106: YES).
In the case of a small impact, the power supply voltage may be reduced only once below a predetermined threshold level. However, in such a case, it is considered that the impact is small and the influence on the electronic circuit is small. Therefore, it is excluded from the detection target.
[0029]
The CPU 24 that has detected an impact as described above adds 1 to the cumulative number of impacts stored in the FROM 31 (S111), and then stores the impact application time based on the stored waveform (S112).
Subsequently, the CPU 24 displays an impact warning message on the liquid crystal display unit 4 for a predetermined time (S113). As a result, the message “Please do not apply impact” is displayed on the liquid crystal display unit 4, so that the user knows that the user has given a large impact to the barcode reader 1. Handle carefully.
[0030]
The CPU 24 switches to the main battery 18 (S114), permits an interrupt (S108), and then returns to the main program (not shown).
With the above operation, every time an impact is applied to the barcode reader 1, the impact information indicating the number of impacts or the magnitude of the impact is stored in the FROM 31, so that the impact information stored in the FROM 31 is read out. The influence of the impact of the barcode reader 1 can be estimated.
[0031]
On the other hand, when the user removes the main battery 18 in order to replace the main battery 18 of the barcode reader 1, the voltage of the power supply line 33 is lowered below a predetermined threshold level as shown in FIG. The state continues. Therefore, as shown in FIG. 5B, when the voltage of the power supply line 33 remains below the predetermined threshold level, the CPU 24 determines that the battery has been removed (S107: YES), and displays a battery removal warning as a liquid crystal. Displayed on the display unit 4 for a predetermined time. As a result, a message “Battery removed” is displayed on the liquid crystal display unit 4, so that the user knows that the battery has been removed.
Then, the CPU 24 turns off the sub-battery 8 (S110) and then permits an interrupt (S108). Thereby, the consumption of the sub-battery 8 can be reduced and the DRAM can be backed up reliably.
[0032]
According to such an embodiment, when the power supply voltage from the main battery 18 falls below a predetermined threshold level, the power supply voltage is monitored for a predetermined time, and the power supply voltage is again reduced below the predetermined threshold level. When it is down, it is judged that the impact is applied and the fact is notified, so that it is possible to detect the impact application with a simple configuration and notify the user without using an expensive sensor such as an acceleration sensor or an impact sensor. be able to.
[0033]
In addition, when the impact application is detected, the power source is switched from the main battery 18 to the sub battery 8 and power is supplied to the CPU 24 from the sub battery 8 for backing up the DRAM 23. Therefore, the CPU 24 removes the main battery 18. Even if it is a case, it can operate | move and it can be judged reliably whether it is an impact application or battery removal.
[0034]
Further, when the power source is switched from the main battery 18 to the sub battery 8 in this way, power is supplied from the sub battery 8 only to the minimum electronic circuit necessary for the subsequent operation, and a high load circuit that does not require power supply is supplied. Since the power supply is stopped, the consumption of the sub-battery 8 can be greatly reduced.
Further, when it is determined that the impact is applied, the power source is returned to the main battery 18, and when it is determined that the battery is detached, the power supply from the sub battery 8 is stopped, so that the sub battery 8 is used as a power source for a long time. This can be prevented.
[0035]
The present invention is not limited to the above embodiment, and can be modified or expanded as follows.
The number of times that the voltage of the power supply line 33 is lowered again below the predetermined threshold level within a predetermined time after the voltage of the power supply line 33 is reduced below the predetermined threshold level is detected, and the impact application or battery removal is determined based on the number of times. It may be. Alternatively, the time from when the voltage of the power supply line 33 is lowered to a predetermined threshold level to the next time may be measured, and impact application or battery removal may be determined based on the measurement time.
The present invention may be applied to an ID tag reader.
[Brief description of the drawings]
FIG. 1 is a block diagram showing an electrical configuration of a barcode reader according to an embodiment of the present invention. FIG. 2 is a sectional view of the barcode reader. FIG. 3 is a battery mounting portion of the barcode reader with the cover removed. [Fig. 4] Diagram showing CPU interrupt program [Fig. 5] Power supply voltage waveform diagram when applying impact and battery replacement [Explanation of symbols]
1 is a bar code reader (portable reader), 4 is a liquid crystal display (abnormality notification means), 8 is a secondary battery, 18 is a main battery, 21 is a switching element (switching means), 19 is a leaf spring (contact), Reference numeral 23 is a DRAM (volatile storage means), 24 is a CPU (voltage down detection means, power supply voltage measurement means, determination means), and 29 is a gate element (power supply stopping means).

Claims (8)

A main battery that feeds power in contact with the contacts;
Voltage down detection means for detecting that the power supply voltage from the main battery has dropped below a predetermined level;
Power supply voltage measuring means for measuring the power supply voltage from the main battery;
A determination unit that monitors a measurement voltage by the power supply voltage measurement unit for a predetermined time when the voltage down detection unit detects a decrease in the power supply voltage, and determines that an impact is applied when the measurement voltage is reduced again below a predetermined level; A portable reader device comprising: Volatile storage means for storing read data;
A secondary battery that backs up the volatile storage means;
Switching means for switching the power source between the main battery and the sub battery,
The determination means determines that the battery is detached when the state in which the measurement voltage by the power supply voltage measurement means is below a predetermined level continues for a predetermined time,
The switching means switches from the main battery to the sub battery when the voltage down detection means detects a decrease in power supply voltage, and from the sub battery to the main battery when the judgment means judges that an impact is applied. 2. The portable reading device according to claim 1, wherein when the determination unit determines that the battery is detached, power supply by the sub battery is stopped. Power supply stopping means for stopping power supply from a power supply to a predetermined electronic circuit is provided,
3. The portable reader device according to claim 2, wherein the power supply stopping unit stops power supply from a power source to a predetermined electronic circuit when the voltage down detection unit detects a decrease in the power supply voltage. 4. The portable reader according to claim 3, wherein the predetermined electronic circuit is a high load circuit. The portable reader according to claim 1, wherein the volatile storage unit stores information regarding the impact when the determination unit determines that the impact is applied. 6. The portable reader according to claim 5, wherein the information on the impact is a time when the impact is applied. 6. The portable reader according to claim 5, wherein the information on impact is the number of times the impact is applied. 8. The portable reader according to claim 1, further comprising an abnormality notifying unit for notifying an abnormality when the determining unit determines that an impact is applied.

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