JPH08153154A - Bar code scanner - Google Patents

Abstract

PURPOSE: To surely read bar code data even if a bar code label shifts in relative position to a read part or changes in code contents. CONSTITUTION: The scanner 10 is provided with a bar code label detecting means 42, an elapsed time counting means, a decision means, and a scanning speed adjustment control means, and switches and adjusts the scanning speed of a scanning beam B to a speed slower than a previously set reference scanning speed unless the bar code data can be read even after the elapsed time Ti counted from when the bar code label detecting means 42 detects the bar code label 100 moving toward a scanning effective area RA exceeds a set time Ts.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bar for irradiating a scanning beam from a scanning window to the outside of a scanning effective area, and receiving reflected light from a bar code which has entered the scanning effective area to read bar code data. Regarding code scanner.

[0002]

2. Description of the Related Art Referring to FIG.
Is a structure in which a main body case 11 is provided with a light emitting device 20 including a semiconductor laser, a scanning unit (motor 17, polygon mirror 18, reflection mirrors 19A and 19B, etc.), a reading unit, a control unit 30, and the like.

The main body case 11 comprises a bottom case 12 and an upper cover 13, and an opening 14 of the upper cover 13.
A scanning window 15 made of a glass plate is provided in the.
Light emitter 20, polygon mirror 18 and reflection mirror 19
A and 19B are attached to the bracket 16 with their relative positions fixed. Therefore, the scanning beam B can be emitted from the scanning window 15 to the external effective scanning area RA.

The reading unit includes, for example, a light receiver for receiving reflected light from a bar code label 100 (bar code 101) attached to the product 200 and converting it into an electric signal, an A / D converter, and a bar code decoding unit. Consisting of and Barcode 1
The bar code data stored in 01 is read. This light receiver includes reflection mirrors 19A and 19B and a polygon mirror 1.
8. Reflected light from the barcode label 100 (101) is incident through a light collecting half mirror (not shown). Although not shown in FIG. 5, it is fixedly arranged on the side surface (front side of the paper surface).

The above-mentioned polygon mirror type scanning unit (1
7, 18, 19A, 19B, etc.), the scanning beam B
The speed within the effective scanning area RA, that is, the scanning speed is proportional to the rotation speed of the polygon mirror 18. The higher the scanning speed, the higher the reading work efficiency. Therefore,
The reference scanning speed is generally selected and set as high as possible in consideration of conditions such as vibration and cost.

The light intensity of the scanning beam B output from the light emitter 20 is a predetermined light intensity when the reflected light from the barcode label 100 (101) is incident on the light receiver forming the reading section. It is selected and set so that it can have.

In such a bar code scanner 10, the bar code label 10 attached to the product 200 or the physical distribution object is attached.
The bar code data can be read only by moving 0 in the traveling direction X to enter / pass the scanning effective area RA.

[0008]

[Problems to be Solved by the Invention] However, the product 2
The barcode data may not be read depending on the form such as 00, the position of the barcode label 100 attached to the product 200 or the like, or the code content of the barcode 101 itself. Mainly, barcode label 10
0 is likely to occur when it passes through the scan effective area RA in a state where it is largely separated upward from the scanning window 15 in FIG.

That is, even if the light intensity of the scanning beam B is constant, if the bar code label 100 is distant, that is, if the relative position with respect to the reading portion changes, the bar code label 10 will change.
Since the reflected light from 0 diffuses on the way, it is considered that the intensity of light incident on the light receiver forming the reading unit becomes weak.

Thus, the conventional bar code label 10
The reading speed is set to 0 in the X direction at a speed lower than the daily standard speed, and the reading operation is performed again. However, in the measure to reduce the progressing speed, not only the re-reading operation itself for the barcode label 100 is time-consuming, but also the subsequent similar products 200 and the like (barcode label 100) have a low progressing speed which is different from the daily routine. Barcode label 10
Since 0 has to be moved, the rhythm is out of order, work efficiency is reduced, and the mental and physical burden on the operator is increased.

The above problems are also common to the case where the scanning unit is a so-called hologram scanning system.

An object of the present invention is to provide a bar code scanner capable of surely reading bar code data even if the relative position of the bar code label with respect to the reading section or the code content is changed and the traveling speed is not reduced. Especially.

[0013]

The cause of the above-mentioned conventional problems is that the light intensity of the reflected light incident on the light receiver forming the reading section becomes weak. Then, the light intensity of the scanning beam from the light emitting device forming the scanning unit may be increased. However, this measure leads to an increase in the size of the light emitting device and the cost, and thus is not a good measure and is not practical.

Further examination, if the scanning beam is applied to the bar code label for a longer period of time, the light amount of the reflected light at the light receiver relatively increases. In other words, it is considered that the light intensity of the reflected light becomes strong for the light receiver when the incident time is constant.

Therefore, when the light intensity of the scanning beam output from the scanning unit is constant and the traveling speed of the bar code label is kept constant at a daily traveling speed in order to maintain the working efficiency, the scanning beam is required. The scanning speed of should be lower than the reference scanning speed. However, if the reference scanning speed is set to a lower speed on the safe side from the beginning, the ordinary reading work efficiency will be significantly reduced.

Thus, according to the present invention, it is premised that the traveling speed of the bar code label toward the scanning effective area is within a certain range for maintaining the work efficiency, and the time during which the barcode label enters the scanning effective area is constant. If the bar code data cannot be read even after a lapse of time, the scanning speed can be adjusted to a speed lower than the preset reference scanning speed to increase the amount of light incident on the light receiver forming the reading unit. It is configured to achieve the above object.

That is, the present invention is a bar code scanner which irradiates a scanning beam from a scanning window into an external scanning effective area and receives reflected light from a bar code which has entered the scanning effective area to read bar code data. In, bar code label detecting means for directly or indirectly detecting a bar code label proceeding toward the scanning effective area, and elapsed time counting means for counting an elapsed time from when the bar code label is detected, A judging means for judging whether or not the counted elapsed time is equal to or longer than a set time, and the judging means has judged that the counted elapsed time is equal to or longer than the set time while the bar code data is not yet read. In this case, scanning speed adjustment control means for adjusting the scanning speed of the scanning beam to be lower than the reference scanning speed is provided.

[0018]

In the case of the present invention having the above-mentioned structure, the bar code label detecting means indirectly detects the bar code label which advances toward the scanning effective area or directly detects the product to which the bar code label is attached. To detect. Then, the elapsed time counting means starts counting the elapsed time from the time of detection. Further, the determination means determines whether or not the counted elapsed time is equal to or longer than the set time.

Here, the set time is defined as the time required from the time when the bar code label is detected by the bar code label detecting means to the time when the bar code label starts to enter the scanning effective area at a constant traveling speed and the scanning effective area. If the preset time is set as the sum of the time required to read the bar code data at least once from the time of entering the bar code label, it can be judged that the elapsed time has exceeded the set time. It means that it was unreadable because it passed.

Thus, the scanning speed adjustment control means, if the above judgment is made before the bar code data is read yet, it is decided that the bar code data is unreadable for that reason, and the scanning speed is set to the reference scanning. Adjust to slower than speed. Therefore, since the irradiation time of the scanning beam with respect to the bar code label in the effective scanning area is relatively increased, the amount of light incident on the light receiver forming the reading unit can be increased. Therefore, even if the barcode label passes a long distance, the barcode data can be reread and the barcode data of the same type of barcode label after that can be reliably read without changing the light intensity and approach speed of the scanning beam. it can.

[0021]

Embodiments of the present invention will be described below with reference to the drawings. The bar code scanner 10 is, as shown in FIG.
The basic structure is similar to that of the conventional example (FIG. 5), and the bar code label detecting means (41, 42, 31, 32).
And elapsed time counting means (35) and discrimination means (31, 3)
2) and the scanning speed adjustment control means (31, 32) are provided, and the barcode label 100 which advances toward the scanning effective area RA is the barcode label detection means (41, 42, 3).
1, 32), the scanning speed of the scanning beam B is switched to a speed lower than the preset reference scanning speed when the barcode data cannot be read even after the set time Ts has elapsed. It is configured to be adjustable.

The same parts as those in the conventional example (FIG. 5) are designated by the same reference numerals, and their description will be simplified or omitted.

In FIG. 2, the control unit 30 includes a CPU 3
1, ROM 32, RAM 33 and input / output port (I /
O) 34, and drive controls the entire scanner. The control unit 30 includes a timer 3 that forms elapsed time counting means.
5 and the RAM 33 is provided with a time memory 33T for storing the set time Ts.

The motor 17 for rotating the polygon mirror 18 shown in FIG. 1 is a DC motor and is rotationally driven at a rotational speed according to the level of the voltage signal Sv input to the driver 17D. The driver 17D is fed back with a speed signal from a speed sensor integrated into the motor 17. That is, since the speed control system having the voltage signal Sv as the target value is formed, it is possible to control the rotation speed to a constant value.

Therefore, when the voltage signal Sv is input to the driver 17D as a signal level corresponding to the motor voltage V corresponding to the reference scanning speed, the motor 17, that is, the polygon mirror 18 is rotated at the reference rotation speed. Can be used as the reference scanning speed.

The light emitter 20 which forms a light emitting portion together with a light emission control circuit (not shown) is formed of a semiconductor laser and is capable of continuously outputting a beam (B) having a constant light intensity. In addition, the reading unit includes the light receiver 25 and the A / D shown in FIG.
It is composed of a converter 26 and a barcode decoding unit 27, and outputs the barcode data read from the barcode 101 to the control unit 30.

The bar code decoding section 27 reads the bar code data from the same bar code 101 many times and checks it, and if it is confirmed that the bar code data is good, outputs one bar code data to the control section 30. To do. The barcode data is temporarily stored in the RAM 33 and then transferred to, for example, an electronic cash register.

The bar code label detecting means is the light emitting / receiving device 40 (light emitting device 41, light receiving device 4) shown in FIGS.
2), the ROM 32 storing the detection program, and C
It is formed from the PU 31 and X toward the effective scan area RA.
The barcode label 100 advancing in the direction is detected (YES in ST11 of FIG. 4). In the case of this embodiment, the barcode label 100 is indirectly detected by detecting the product 200 to which the barcode label 100 is attached. This is because it is not the first meaning to inquire the absolute value of the set time Ts or the count elapsed time Ti with high accuracy, and therefore, the barcode label 100 can be detected more reliably and easily.

As shown in FIG. 1, the light emitting device 41 and the light receiving device 42 allow the detection light D and the reflected detection light T to pass through the light passage portion 16A formed in the bracket 16 and hold the holding member 4.
3, and is connected to the input / output port 34 of the control unit 30 by a flexible cable 45.

Therefore, the product 2 provided with the bar code label 100 in which the detection light D travels in the X direction shown in FIG.
When 00 is irradiated and the reflected detection light T is incident on the light receiver 42, the CPU 31 indirectly detects the barcode label 100 by the electric signal output from the light receiver 42 (YES in ST11 of FIG. 4). ) Do. At the same time, the timer 35 is driven (set) (ST12 in FIG. 4). As a result, the barcode label 100 is indirectly detected (ST11
The elapsed time Ti from the time of YES) is counted.

The discriminating means discriminates whether or not the elapsed time Ti counted by the timer 35 has become equal to or longer than the set time Ts set and stored in the time memory 33T, and the ROM 32 and the CPU 3 which store the discriminating program.
1 and is executed in ST15 of FIG.

As shown in FIG. 1, the set time Ts is the time T1 from when the bar code label 100 is detected by the bar code label detecting means to when the bar code label 100 starts to enter the scan effective area RA and the scan effective area RA. Is determined as the sum of time T2 while moving. This time T2 is
The time is set such that the barcode data can be read at least once at the beginning. Further, for example, the barcode label 10 may be determined so that it can be read three times or more.
Like the time it takes for 0 to pass the scan effective area RA,
Should not be long. This is because it causes a slowdown of the scanning speed adjusting operation described later.

The scanning speed adjustment control means has not yet read the bar code data (NO in ST13 of FIG. 4).
In the meantime, the counting elapsed time T is reached by the determination means (31, 32).
When it is determined that i has exceeded the set time Ts (ST
(YES in 15) is a means for adjusting the scanning speed of the scanning beam B to be lower than the reference scanning speed, and is formed from the ROM 32 and the CPU 31 in which the speed adjustment control program and the speed switching adjustment data are stored, and in ST16 of FIG. To be executed.

As the speed switching adjustment data, for example, a plurality of set times Ts and respective scanning speeds corresponding thereto, that is, data in which the level of each voltage signal Sv (each motor voltage V) input to the driver 17D is stored as a table, etc. However, in the case of this embodiment, as shown in FIG. 3, a function [f for obtaining the deceleration component ΔV with respect to the motor voltage V is obtained.
(Ti)] data. That is, if the elapsed time Ti with respect to the set time Ts is long, it means that the bar code data cannot be read because the amount of light incident on the light receiver 25 forming the reading unit is very small. Is data for increasing the deceleration amount ΔV [= f (Ti)] in proportion to. Therefore, the adjusted motor voltage V can be switched and adjusted to be smaller than the reference motor voltage Vb corresponding to the reference scanning speed.

That is, in this embodiment, the scanning speed restoration adjustment control means (CPU 31, ROM 32) is provided, and when the bar code data is read (YES in ST13), the size is proportional to the elapsed time Ti. Acceleration amount ΔV [= f
(Ti)] is added to the motor voltage V, and the scanning speed after being once switched and adjusted by the scanning speed adjustment control means (31, 32) to the reference scanning speed as long as the bar code data can be read. Adjustable restoration (ST18)
This is because

Thus, according to this restoration adjustment, ST1
When the motor voltage V on the right side of 8 is the reference motor voltage Vs, it becomes possible to increase the motor voltage V above the reference motor voltage Vs by the acceleration amount ΔV [= f (Ti)].
That is, as long as the barcode data can be read within the permission range of the driver 17D, the motor 17, etc. (ST
13), it is possible to increase the scanning speed above the reference scanning speed. To make this possible,
After the restoration adjustment, the set time Ts is rewritten to the elapsed time Ti. However, when the elapsed time Ti is shorter than the set time Ts, as shown in FIG. 3, the acceleration amount ΔV with respect to the unit time difference (Ts-Ti).
Is smaller than the deceleration ΔV.

Next, the operation of this embodiment will be described. It is assumed that the motor 17 is rotated at the reference motor voltage Vb (ST10 in FIG. 4). Therefore, the scanning speed of the scanning beam B is constant at the reference scanning speed. Here, the operator selects the product 200 (bar code label 1 shown in FIG.
00) toward the scanning effective area RA in the X direction at a normal traveling speed.

Then, the barcode label detecting means (4
1, 42, 31, 32) indirectly detect the product 200, that is, the barcode label 100 (YES in ST11). The CPU 31 drives (sets) the timer 35 forming the elapsed time counting means (ST12). Elapsed time T
i starts counting.

The discriminating means (31, 32) includes a timer 35.
The elapsed time Ti and the set time Ts set in the time memory 33T are read (ST14), and Ti ≧ Ts
It is determined whether or not (ST15). If the scanning speed adjustment control means (31, 32) determines that the elapsed time Ti has become equal to or longer than the set time Ts (YES in ST15) even if the bar code data cannot be read (NO in ST13), the ROM 32 is stored in the ROM 32. Based on the stored speed switching adjustment data, the rotation speed of the motor 17 is switched and adjusted to be lower than the reference rotation speed (ST16, ST10).

That is, the motor voltage V is deducted from the reference motor voltage Vb by a deceleration amount ΔV [= f (Ti)] corresponding to the length of the elapsed time Ti determined by the relationship with the set time Ts. V-f (Ti)] (ST16). Specifically, the voltage signal Sv of the level corresponding to the value [Vf (Ti)] is input to the driver 17D. After that, the timer 35 is reset (ST20).

Therefore, since the scanning speed of the scanning beam B becomes slower than the reference scanning speed (ST10), the product 20
Even when the traveling speed of 0 in the X direction and the light intensity of the scanning beam B are constant, the amount of light received by the light receiver 25 forming the reading unit increases. Therefore, the same product 200 (barcode 10
Rereading of 1) can be reliably performed. Further, the same type of barcode 101 (200) thereafter can be surely read similarly.

On the other hand, when the bar code data is read during the period of Ti <Ts (YES in ST13), the elapsed time Ti until then is read (ST17), and the motor voltage V is set to the elapsed time Ti. Acceleration amount according to the length of
The value is adjusted higher by V [= f (Ti)] (ST18). Therefore, if the motor voltage V has been adjusted to be lower than the reference motor voltage Vb (ST16), it can be returned to the reference motor voltage Vb side.

Further, when the previous motor voltage V is the reference motor voltage Vb, the scanning speed can be made higher than the reference scanning speed although the acceleration amount ΔV is small.
In this case, the set time Ts is switched to the elapsed time Ti. This is because the reading can be performed even in a short time (Ti). Thus, the scanning speed will not be continuously increased.

However, according to this embodiment, the bar code label detecting means (41, 42, 31, 32), the elapsed time counting means (35), the discriminating means (31, 32),
The scanning speed adjustment control means (31, 32) is provided, and the barcode label 100 that advances toward the effective scanning area RA is the barcode label detecting means (41, 42, 31, 32).
The elapsed time Ti counted from the time when it is detected in
If the bar code data cannot be read even when the scanning speed is equal to or more than s, the scanning speed of the scanning beam B can be switched and adjusted to a speed lower than a preset reference scanning speed. Receiver 2 that can increase the relative irradiation time of the bar code 101 to the bar code 101 and form a reading unit
It is possible to increase the amount of light incident on the light source 5. Therefore, even if the relative position of the barcode label 100 with respect to the reading unit or the code content changes, and the traveling speed is not reduced, the barcode data can be reliably read.

Further, the scanning speed adjustment control means (31, 3
2) is composed of the ROM 32 storing the speed adjustment control program and the speed switching adjustment data and the CPU 31, and the speed switching adjustment data obtains the deceleration amount ΔV stepwise with the count elapsed time Ti as a variable. Function [f (T
i)] Since it is data, it does not cause hunting. In addition to the stepwise switching adjustment shown in FIG. 3, continuous adjustment is also easy.

Further, the scanning speed restoration adjustment control means (31,
32) is provided, and the scanning speed which is once switched and adjusted to a low speed by the scanning speed adjustment control means (31, 32) can be automatically restored and adjusted to the reference scanning speed as long as the bar code data can be read. Therefore, after the bar code label 100 (commodity 200) that causes the scanning speed adjustment control means (31, 32) to be read again can be immediately and automatically restored to the reference scanning speed, it is easy to handle and easy to use. You can improve more.

Further, since the function [f (Ti)] data is formed such that the deceleration ΔV of the motor voltage V increases as the elapsed time Ti becomes longer, it is the scanning speed after the scanning speed adjustment. The barcode data can be surely read again.

Further, since the set time Ts is automatically rewritten to the elapsed time Ti when the bar code data can be read, the judgment operation of the judgment means (31, 32) and the scanning speed adjustment based on the judgment operation. Operations and can be processed at higher speed.

Furthermore, if the function [f (Ti)] data has the same unit time difference (Ts-Ti), the elapsed time Ti shown on the left side of FIG. 3 is shorter than the rewritten set time Ts. Since the speed component ΔV is made smaller than the deceleration component ΔV shown on the right side of the figure, the adjustment range of the scan speed that enables reading is large, and the adjustment range for further increasing the scanning speed is small. it can. Therefore, re-readability can be further ensured and the speed can be carefully increased.

[0050]

According to the present invention, a bar code label detecting means, an elapsed time counting means, a discriminating means and a scanning speed adjusting control means are provided, and a bar code label which advances toward a scanning effective area is a bar code label. Even if the elapsed time counted from the time when it is detected by the code label detection means exceeds the set time,
If the bar code data cannot be read, the scanning speed of the scanning beam can be adjusted to a speed lower than the preset reference scanning speed. Can be made longer and the amount of light incident on the light receiver forming the reading unit can be increased. Therefore,
Even if the relative position of the barcode label with respect to the reading unit or the code content is changed and the traveling speed is not reduced, the barcode data can be reliably read. In particular, even a bar code attached to a large-sized product and distant from the scanning unit can be reliably read, so that the applicability can be expanded, the scanning work efficiency can be greatly improved, and the handling is easy.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

FIG. 2 is likewise a circuit diagram.

FIG. 3 is likewise a diagram for explaining speed switching adjustment data.

FIG. 4 is likewise a flowchart for explaining the operation.

FIG. 5 is a cross-sectional view for explaining a conventional example.

[Explanation of symbols]

10 Bar Code Scanner 11 Main Body Case 12 Bottom Case 13 Top Cover 14 Opening 15 Scanning Window 16 Bracket 16A Light Passing Part 17 Motor 18 Polygon Mirror 19A, 19B Reflecting Mirror 20 Light Emitting Device 25 Photo Receiver 26 A / D Converter 27 Bar Code Decoding Part 30 control part 31 CPU (bar code label detection means, discrimination means,
Scan speed adjustment control means) 31 ROM (bar code label detection means, discrimination means,
Scanning speed adjustment control means) 33 RAM 33T time memory 34 input / output port 35 timer (elapsed time counting means) 40 light emitting and receiving device 41 light emitting device (bar code label detecting means) 42 light receiving device (bar code label detecting means) 43 holding member 100 bar code label 101 bar code B scanning beam RA scanning effective area D detection light T reflection detection light X traveling direction Vs reference motor voltage V motor voltage Ts set time Ti elapsed time

Claims (1)

[Claims] 1. A bar code scanner for irradiating a scanning beam into an external scanning effective area from a scanning window and receiving reflected light from a bar code which has entered the scanning effective area to read bar code data. A bar code label detecting means for directly or indirectly detecting a bar code label traveling toward the effective area, an elapsed time counting means for counting an elapsed time from when the bar code label is detected, and a counted progress. A determining means for determining whether or not the time has exceeded the set time, and the scanning when the elapsed counting time has been determined by the determining means while the bar code data has not been read yet. And a scanning speed adjusting control means for adjusting the scanning speed of the beam to be lower than the reference scanning speed. .