JPS62200477A - Bar-code reading method - Google Patents

Abstract

PURPOSE:To eliminate an influence by a variation of a speed by providing a clock bar part and a data bar part on a bar-code part, and also, executing a read operation of a data bar read part in synchronism with a read signal of a clock bar read part. CONSTITUTION:A bar-code part 3 is constituted of two tracks of a clock bar part 3a on which a bar has been provided at an equal interval, and a data bar part 3b which has recorded a data. Light beams which transmit through slits 30a, 30b of a bar-code film 1 and a slit film 29, and reach photosensors 27a, 27b are shielded and intermitted by the clock bar part 3a and the data bar part 3b of the car code part 3, respectively, and the bar-code part 3 is read by a bar-code sensor 19. Bar-code signals which have been read are inputted to a CPU, and decoded, respectively. In this way, read signals of both the bar parts are obtained separately, and a signal of the data bar part is read in synchronism with an output signal of the clock bar part, therefore, an influence by a variation of a speed is eliminated.

Description

DETAILED DESCRIPTION OF THE INVENTION (A) Industrial Application Field The present invention relates to a bar code that reads a bar code attached to a bar code plate by relatively scanning a bar code reading unit in a direction perpendicular to the bar. Regarding code reading method.

(b) Conventional technology In general, when inputting data into electronic devices such as urine sugar meters,
Conventionally, a barcode plate a shown in FIG. 10(a) is used. This barcode plate a has an opaque bar C on a base b.
and transparent bars d are arranged in sequence in the horizontal direction, with wide and narrow bars being appropriately combined. The barcode attached to the barcode plate a is read by a barcode sensor comprising, for example, a light emitting element and a light receiving element. Barcode Fi shown in FIG. 10(a)
The waveform of a read by the barcode sensor is the 10th waveform.
As shown in Figure 1), the transparent part is high and the black part (opaque part)
becomes low. The high and low widths of the read signal are detected, and are binarized as "1" for wide and "O" for narrow, for example.

In conventional barcode reading of this type, as shown in FIG. 11, the width (to) of the detected bar is first measured (
STII). Then, this measured width t0 is set to a narrow value (
TN) (ST12). This 5TII, 5
The process at T12 is performed to obtain a bar width standard, and the first bar is used as a narrow bar as a temporary standard.

Next, measure the next bar width (1fi)5TI3),
Whether this bar is a narrow value, e.g. 0.5TN≦t, 1
It is determined whether ≦1.5TN (ST14).

If this judgment is YES, the data “0” is stored (5T15) and the code width t is set to a new narrow value T7.
It is updated and stored as (ST16).

On the other hand, if 5T14 is not a narrow value, it is determined whether it is a wide value, for example, 1.5T, s t , ≦2.57N (STI 7). If this determination is YES, the data "1" is determined. 5T18), and update and store 1/2 of its code width t7 as a narrow value Tn (ST
19). If it is determined in 5T17 that the value is not a wide value, error processing is performed.

After updating the narrow value of 5T16 or 5T19, if the read data is not final, update from 5T20 to 5T13.
Returning to step 1, the next bar width (tl) is measured, and the same process is repeated m times. The reason why the reference value (T1) is updated every time the bar width is measured at 5T16.5T19 is to follow the change in scanning speed.

(c) Problems to be solved by the invention The barcodes used in the above conventional method are arranged horizontally in wide and narrow directions, and decoding is performed by relative scanning with a barcode sensor. Since it converts into the dimension of time and determines whether it is "0" or "■" by measuring the length of time, for example, when scanning a barcode plate by manually pulling it, the speed changes rapidly. ,
There is a possibility that it will be difficult to judge whether it is “O” or “1”. In the specific method shown in Fig. 11 above, in which the reference value used to determine wide and narrow is dynamically updated, some speed fluctuations can be absorbed, but the rate of speed change still differs between narrow and wide. If the ratio approaches (then it becomes impossible to distinguish between the two).

Furthermore, in width measurement, the dynamic range of time measurement becomes larger, the timer counter becomes larger, and processing time is required to determine the size, which cannot be processed by a small-sized, slow microcomputer. Therefore, if a microcomputer with a large processing capacity is used, there is a problem in that the barcode reading device becomes expensive.

In view of the above, it is an object of the present invention to provide a barcode reading method that enables accurate barcode decoding regardless of the scanning speed of the barcode and that can contribute to the realization of an inexpensive device.

(d) Means and operation for solving the problem The barcode reading method of the present invention provides a barcode reading unit (barcode sensor) for a barcode unit in which a plurality of bars are arranged.
In the method of reading the barcode of the barcode section by scanning the barcode relative to the bar in a direction perpendicular to the bar, the barcode section is provided with a clock bar section and a data bar section, and the barcode reading section is provided with a clock bar section. A reading section and a data bar reading section are provided separately, and the reading operation of the data bar reading section is performed in synchronization with a read signal from the clock bar reading section.

With this barcode reading method, even if the scanning speed of the barcode section suddenly changes, only the reading timing of the clock bar section changes accordingly, and the data bar is read in synchronization with the reading output of the clock bar. , follows speed changes and is not affected by speed changes. Furthermore, since the time width is not measured, there is no need for a counter or the like for time measurement.

(e) Examples Hereinafter, the present invention will be explained in more detail by taking as an example the case where the present invention is applied to a urinary sugar needle.

FIG. 3 is an external perspective view of the example blood sugar needle.

In the figure, a blood sugar needle 11 is connected to a case 12 made of synthetic resin.
The measuring section, barcode reading section, etc. are housed inside, and case 1
A power switch 13, a measurement switch 14, and a liquid crystal display 15 for displaying blood sugar levels and the like are provided on the top surface of the device 2. Inside the case 12, a measuring section cover 16 that covers the measuring section is provided so as to be openable and closable. The upper surface of the cover 16 is provided with a stick insertion hole 16a into which a stick (not shown) made of a thin strip of synthetic resin or the like with a test paper pasted at its tip is inserted. A test paper immersed in blood to cause a color reaction is placed in the measurement section, and the reflectance or transmittance is measured by a light emitting element and a light receiving element (not shown) provided facing the measurement section. Based on these values, the blood sugar level is calculated and displayed on the display 15.

However, since this invention is not directly related to the measuring section, detailed explanation will be omitted.

In this invention, the barcode reading section 5 provided on the side of the measuring section cover 16 is important. The barcode film 1 is inserted through the barcode reading section 5. This barcode film 1 has a barcode portion 3 on the upper surface of the film base 2, as shown in an enlarged view in FIG.
and an insertion direction indication mark 4.The barcode section 3 consists of a clock bar section 3a in which bars are provided at equal intervals, and a data bar section 3b in which data is recorded.
It consists of tracks. This barcode film 1
is the blood IP stored in the circuit of the blood sugar needle 11! A calibration curve table for value quantification needs to be calibrated for each test strip loft, so it is provided for inputting this calibration data.

Next, the structure of the barcode reading section 5 into which the barcode film 1 is inserted and the barcode section 3 is read will be explained.

A slit-shaped barcode film outlet hole 18 similar to the slit-shaped barcode film insertion hole 17 is provided at the front of the case 12 . As shown in FIGS. 4 and 5, the barcode film insertion hole 17 and the barcode film outlet hole 18 are constituted by an upper unit member 25 and a lower unit member 20 each having an arcuate cross section and provided inside the case 12. They are communicated by a communication path 21 that includes a barcode sensor 19.

A light emitting diode element (L
ED) Cylindrical holding part 22a that holds 24a and 24b
, 22b are arranged in parallel. The LEDs 24a and 24b are
The communication path 21 is faced through window holes 23a and 23b formed in the lower unit member 20. Note that the LED can be one common to photosensors 27a and 27b, which will be described later.

The upper unit member 25 includes the LEDs 24a, 24.
Photosensors 27a and 27b made of phototransistors, etc., are mounted on the cylindrical holding portions 26a and 27b so as to face the
26b.

A slit film 29 whose both ends are supported by grooves 28 and 28 provided in the upper unit member 25 is attached to the front surface of the photosensors 27a and 27b so that its center portion faces the lower unit member 20. This slit film 29 has elongated slits 30a and 30b formed in a light-shielding synthetic resin plate and facing window holes 23a and 23b and photosensors 27a and 27b, respectively.

FIG. 6 is a circuit block diagram of the barcode reading section.

The LEDs 24a and 24b are driven by constant current drive circuits 41 and 42, respectively, in response to commands from the CPU 40, and are driven by the photo sensors 27a and 27 through the slits 30a and 30b of the slit film 29.
The light is received individually by the beams b, and a current flows through the beams.

This light receiving current is transmitted through current/voltage converters 42a and 4, respectively.
2b, it is converted into a voltage signal, and the waveform shaping circuit 43a, 43
The waveform is shaped in step b and taken into the CPU 40.

Note that the barcode film 1 is inserted into the communication path 21,
A film detection switch 44 is turned on at the tip @1a of the barcode film 1, and the on signal is taken into the CPU 40.

Next, the operation of reading the barcode on the barcode film 1 will be explained.

First, the power switch 13 of the blood sugar needle 11 is turned on to set the barcode reading state. Barcode film 1 is
Insert the barcode film insertion hole 1 so that the barcode part 3 faces the front of the blood sugar needle 11 and from the insertion direction indication mark 4.
7 (see Figure 3). Barcode film 1
The tip 1a crosses the interior of the barcode sensor 19, passes through the communication path 21, and is exposed to the outside of the case 12 through the barcode film outlet hole 18 again. At this time, the film detection switch 44 is turned on at the leading end 1a of the barcode film 1, and in response to this, the LEDs 24a and 24b are driven.

The tip 1a of the barcode film 1 exposed through the barcode film outlet hole 18 is pulled by the user, and the entire length of the barcode film 1 passes through the communication path 21 and is taken out to the outside. At this time, the barcode portion 3 passes through the barcode sensor 19. When passing the barcode section 3, the LED
Light is irradiated onto the barcode film 1 from 24a and 24b, and the light that passes through the barcode film l and the slits 30a and 30b of the slit film 29 and reaches the photosensors 27a and 27b is a barcode signal 3, respectively. The barcode section 3 is read by the barcode sensor 19 by being interrupted and interrupted by the clock bar section 3a and data bar section 3b. The read barcode signals are each taken into the CPU 40 and decoded.

As shown in FIG. 1, the decoding process first detects the rising edge of the clock bar section 3a (STI). When the rising edge of the clock bar section 3a is detected, the data section that is applied at that timing is decoded. 3b is transparent (whether the read signal is high or low) is determined (Sr1). If data pad part 3b is transparent (high), data “1” cannot be stored.
T3), conversely, when the data pad part 3b is opaque (low), data "0" is stored.5T4), it returns to STI via Sr1 until all data has been read.
Each time a rising edge of the clock bar portion 3a is detected, the above S
Repeat the processes from TI to ST5 to decode the barcode.

An example of the above decoding operation is shown in FIG. 7. In other words, when the barcode part 3 having the clock bar part 3a and the data bar part 3b as shown in FIG. The signal becomes FIG. 7 (C1), and "1" or "O" is selected depending on the signal level of the data bar at the rising edge of the clock signal to obtain binary data.

Note that although Fig. 7 shows a case where a barcode film with clock bars arranged at equal intervals is moved at a constant speed, as shown in Fig. 8(a), the moving speed V varies with time. Even if the rising timing of the clock signal varies greatly, the data pad portions 3b arranged in parallel also move at the same speed, and therefore the data pad signal also expands and contracts in response to the clock signal. In other words, it is synchronized, so
As shown in FIG. 8(b), the read data is
It is exactly the same as figure (e).

In the above embodiment, the data per signal is read at the rising edge of the clock signal, but it may of course be read at the falling edge of the clock signal, or as shown in FIG. , the data per signal may be read at both the rising and falling points of the clock signal.

Further, in the above embodiment, the barcode film is moved relative to the barcode sensor, but the barcode sensor may be moved conversely.

Therefore, the base on which the barcode is attached does not need to be limited to film.

Furthermore, although the above embodiment has been described using a blood sugar needle as an example, it goes without saying that the present invention can be applied to barcode reading devices for various devices.

(f) Effects of the Invention According to the present invention, a clock bar section and a data pass section are provided in the bar code section, reading signals of a section of both bars are obtained individually, and the data pass section is read in synchronization with the output signal of the clock bar section. Since this device reads the signal of the section, it has the advantage of being completely unaffected by changes in speed.

In addition, unlike conventional methods, there is no need to compare time widths, so there is no need for a counter for counting time, and there is no need for complicated comparisons, making the algorithm for decoding simpler and smaller. It can be realized even with a small-scale microcomputer, and an inexpensive barcode reading device can be obtained.

[Brief explanation of drawings]

FIG. 1 is a flow diagram for explaining the operation of the barcode reading section of the blood sugar needle according to the embodiment of the present invention, FIG. 2 is an enlarged view of the barcode film used in the blood glucose meter, and FIG. ,
FIG. 4 is a longitudinal sectional view of the barcode reading section of the blood glucose meter, and FIG. 5 is a cross-sectional main part of the barcode reading section taken along line V-V in FIG. 4. The diagram shown in FIG. 6 is a program diagram showing the circuit configuration of the barcode reading section.
FIG. 7 is a diagram for explaining the decoding operation of the same barcode reading section, FIG. 8 is a diagram for explaining the operation when the moving speed of the barcode section changes in the same barcode reading section,
FIG. 9 is a diagram for explaining another example of decoding operation, and FIG.
This figure is a diagram for explaining a conventional decoding operation, and FIG. 11 is a flow diagram for explaining the conventional method. 1: Barcode film, 3: Barcode section, 3a: Clock bar section, 3b: Part of data pad, 24a24b:
LED. 27a and 27b: Photosensors. Patent applicant Tateishi Electric Co., Ltd. Agent
Patent Attorney Shigeru Nakamura Figure 9 Figure 2 Figure 3 Figure 6 Figure 7 Figure 8 Figure 10

Claims (1)

[Claims] (1) In a barcode reading method in which a barcode reading section is scanned relative to a barcode section in a direction perpendicular to the barcode section in which a plurality of bars are arranged to read the barcode of the barcode section. , the barcode section is provided with a clock bar section and a data bar section, and the barcode reading section is provided with a clock bar reading section and a data bar reading section separately, and the bar code section is provided with a clock bar section and a data bar section. A barcode reading method in which a data bar reading section performs a reading operation.