JP2902968B2 - 2D code reader - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a two-dimensional code reader for reading two-dimensional codes such as multi-stage bar codes and matrix codes.

[0002]

2. Description of the Related Art For example, as a two-dimensional code reader for reading a two-dimensional code such as a matrix code printed on a printing medium such as a package of a product for sale, a portable two-dimensional code reader that is used by an operator while holding it by hand is used. Are known.

FIG. 8A is a cross-sectional view showing a schematic internal configuration of a conventional two-dimensional code reader 1, and FIG.
Is a diagram showing a light source unit 3 described later. FIG.
FIG. 2 is a top view showing the two-dimensional code reader 1.

A two-dimensional code reader 1 includes an LED (light) for irradiating a two-dimensional code with light inside an integrated frame 2.
a light source unit 3 including a plurality of light sources 3-1 to 3-6 each including an emitting diode) and a scattering lens, a reflecting mirror 4, a lens mechanism 5, and a CCD (charge coupled).
(device) A built-in image sensor 6 formed by arranging elements in a matrix and a circuit board 7 (not shown) including a signal processing circuit, a binarization circuit, an identification circuit, a decoding circuit, a communication circuit, etc. ing.

[0005] The circuit board 7 is further electrically connected to a trigger switch 8 provided on the frame 2 and a display lamp 9 composed of an LED.

[0006] The circuit board 7 is electrically connected to a connection cable 10 connected to an external data processing unit (not shown). The connection cable 10 is fixed to the frame 2 via a protection member 11.

An opening is formed on the opposite side of the frame 2 to which the connection cable 10 is fixed, and a cylindrical reading cover 12 is integrally provided on the frame 2 so as to be detachable therefrom. . However, this reading cover 1
Basically, 2 is normally not frequently attached and detached, and is attached and detached only for inspection and repair, for example, and is fitted and fixed so that it does not come off easily during normal use. The opening 13 located on the opposite side of the portion where the reading cover 12 is fitted to the frame 2 serves as a reading port.

As shown in FIG. 8B, the light source unit 3 arranges a plurality of the light sources 3-1 to 3-6 in a line in a straight line, and directly goes to the opening 13 of the reading cover 12. It is fixed in the direction of light irradiation. These light sources 3-1 to 3-6 are
Light sources with the same performance (directivity, brightness, etc.) were all used. For example, when the length of the reading cover 12 is short, a light source having a relatively low luminance is employed. When the length of the reading cover 12 is long, a light source having a high directivity and a relatively high luminance is employed. You.

The reason is that if the optical path from the light source to the two-dimensional code to be read becomes long, the light source having low luminance will not irradiate the corner portion of the reading range with light.

[0010]

As described above, the conventional two-dimensional code reader 1 employs a light source having high directivity and relatively high brightness when the length of the reading cover 12 is long. In addition, there is a problem that the central portion of the light emitted from the light source reflects strong light in a halation manner, and the central portion irradiated with the light on the print medium cannot be read.

As the optical path from the light sources 3-1 to 3-6 to the two-dimensional code becomes longer and the reading range becomes larger, uneven irradiation by the light source is a barrier to accurate two-dimensional code reading. There was a problem.

Accordingly, an object of the present invention is to provide a two-dimensional code reader which can irradiate a two-dimensional code with light having a uniform intensity and can accurately read the two-dimensional code. I do.

[0013]

According to the first aspect of the present invention,
In a two-dimensional code reader for reading a two-dimensional code by irradiating light to the two-dimensional code, irradiating the two-dimensional code with light, and reading the two-dimensional code, a light source having high directivity is provided. An irregular reflection member for irregularly reflecting light from the light source to the two-dimensional code positioned at the reading opening; and a linear reflection path provided from the light source to the reading opening.
The light shielding member provided is provided.

[0014] According to a second aspect of the present invention, there is provided a method for printing on a print medium.
The reading port on the two-dimensional code
Irradiate the light to the code, receive the reflected light, and
In a two-dimensional code reader that reads
1 light source and this highly directional light source
A second light source having low directivity, and light from the first light source.
Is irregularly reflected on the two-dimensional code positioned at the reading port.
And a diffusely reflecting member.

According to a third aspect of the present invention, the directivity is high.
A light shielding member was provided on a straight optical path from the light source to the reading port.
Things. The invention described in claim 4 is claim 1 or
The two-dimensional code reader according to claim 2.
The irregular reflection member is provided inside the reading port.
It is characterized by that.

[0016]

According to the first aspect of the present invention, the directivity is high.
The light from the light source is irregularly reflected by the irregular reflection member and
Irradiated on the card. Therefore, light with high directivity is directly
Without irradiating the original code, the entire 2D code
Illuminate evenly. In addition, the light shielding member allows directivity
Ensures high light source light is directly applied to the 2D code
2D code has random reflection by diffuse reflection member
It is more reliable because it is limited only to the emitted light
To uniformly illuminate the entire two-dimensional code.

According to the second aspect of the present invention, the directivity
The light from the high first light source is irregularly reflected by the irregular reflection member.
From a second light source that is illuminated on a two-dimensional code and has low directivity
Is directly and indirectly applied to the two-dimensional code. Obedience
Therefore, in the two-dimensional code, from the first light source to the irregular reflection member
Irradiated with more irregularly reflected light, the second light source
These lights are irradiated. As a result, the entire 2D code is uniform
To illuminate.

According to the third aspect of the present invention, the second aspect is provided.
In addition to the effects of the described invention, the light
Ensures that light from a high-intensity light source is directly radiated to the two-dimensional code
The two-dimensional code,
It is more limited because it is radiated only by the reflected light.
In fact, the entire two-dimensional code is uniformly illuminated.

In the invention according to claim 4, claim 1 is
Alternatively, the two-dimensional code reader according to claim 2.
Wherein the irregular reflection member is provided inside the reading opening.
So that the two-dimensional code can be evenly illuminated.
Wear.

[0020]

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1A is a cross-sectional view showing a schematic internal configuration of a handy type two-dimensional code reader 21 to which the present invention is applied, and FIG. 1B is a view showing a light source unit described later. is there. FIG. 2 is a top view showing the two-dimensional code reader 21.

The two-dimensional code reader 21 includes a light source unit 23 for irradiating a two-dimensional code with light, a reflecting mirror 24, a lens mechanism 25,
An image sensor 26 formed by arranging D (charge coupled device) elements in a matrix, and a signal processing circuit (not shown), a binarization circuit, an identification circuit, a decoding circuit,
A circuit board 27 composed of a communication circuit and the like;
-9.

The circuit board 27 is further electrically connected to a trigger switch 28 provided on the frame 22 and a display lamp 29 composed of an LED.

The circuit board 27 is electrically connected to a connection cable 30 connected to an external data processing unit (not shown). The connection cable 30 is fixed to the frame 22 via a protective member 31.

The connection cable 30 of the frame 22
An opening is formed on the opposite side to which is fixed, and a cylindrical reading cover 32 is provided in the frame 22 so as to be integrally detachable. However, the reading cover 32 is usually not frequently attached and detached, and is attached and detached only for inspection and repair, for example, and is fitted and fixed so as not to come off easily during normal use. This reading cover 32
The opening 33 on the opposite side of the portion fitted to the frame 22 serves as a reading port.

Inside the reading cover 32, there is provided a shielding plate 34 as a light shielding member for shielding direct light from the light source unit 23 to the opening 33, and the shielding plate 34 is provided. On the opposite side of the portion, a diffuse reflection surface 35 as a diffuse reflection member surface-treated in white is formed.

As shown in FIG. 1B, the light source unit 23 has a plurality of light sources 23-1 to 23-8 arranged and fixed in a line on a straight line. A total of two light sources 23-1 and 23-2 arranged at both ends thereof are light sources having low directivity as a second light source, and a total of four light sources arranged second and third from both ends are provided. The light sources 23-3 to 23-6 are light sources having high directivity and high luminance as the first light source. The two light sources 23-7 and 23-8 arranged in the center are light sources having low directivity and low luminance as the second light source.

The light source 2 having high directivity and high brightness
3-3 to 23-6 are mounted so that their irradiation directions are open. That is, the second light source 2 from the left end
3-3 is mounted to be tilted to the left, the third light source 23-4 from the left end is mounted to be tilted to the right, the third light source 23-5 from the right end is mounted to be tilted to the left, and 2
The second light source 23-6 is mounted to be inclined rightward.

The frame 22 is formed such that a portion to be gripped by a hand is depressed according to a standard hand size.
The trigger switch 28 is provided in the depressions 36 and 37. As shown in FIG. 2, when a contour line without the concave portion 36 is indicated by a broken line A, the trigger switch 28 is provided so as to fit inside the broken line A.

Although not explicitly shown in FIG. 1, two auxiliary light sources 23-9 are arranged at target positions with respect to the center cross section of the two-dimensional code reader 21. It is a spot light source with low power consumption that goes out. The spot light from the auxiliary light source 23-9 is applied to the reading range or the center thereof and is used as a guide display when the two-dimensional code reader 21 approaches the two-dimensional code printed on the print medium.

FIG. 3 is a block diagram showing a main circuit configuration of the two-dimensional code reader 21. As shown in FIG.

The light sources 23-3 to 23 of the light source unit 23
-6 and the light sources 23-7, 23-8 on the two-dimensional code printed on the print medium (to be read) 41 which is in contact with or close to the opening 33 of the reading cover 32 at a predetermined distance. 35 or the irregularly reflected surface 3
Light with low brightness is irradiated without passing through the light source 5. The reflected light from the two-dimensional code 41 is received by the image sensor 26 via the reflecting mirror 24 and the lens mechanism 25.

The output signal from the image sensor 26 is input to an AGC (automatic time constant control) circuit 42 and also to a calculus circuit 43.

The comparator 44 is provided with the calculus circuit 43.
The signal level output from
The signal is converted into binary data by comparing with a signal output from the GC circuit 42, and the binary data is output to the decoding circuit 45.

The decoding circuit 45 converts the binary data into code data and outputs it to the data processing unit 45 via the connection cable 30.

FIG. 4 is a diagram showing the flow of an interrupt generation process performed by the data processing unit 45. This is a process for periodically performing an interrupt process described later at regular time intervals.

First, the timer is initialized and the timer is started.

Next, the timer counts a preset time and enters a standby state until the timer is completed. When the timer is completed, an interrupt signal is generated, and the first time in the interrupt generation processing is performed again. The process returns to the initialization of the timer.

FIG. 5 is a diagram showing the flow of an interrupt process performed by the data processing unit 45 upon generation of an interrupt signal.

First, an imaging start request (imaging request) is made. When the imaging start request is made, the illuminated auxiliary light source 23-9 is turned off, and the reading light sources 23-1 to 23-8 are turned off. Turn on.

Next, the image sensor 26 enters a standby state until the image sensor 26 captures one frame image and completes the imaging. When the imaging is completed, the light sources 23-1 to 23-8 for reading are turned off, and the auxiliary light source is turned off. Turn on 23-9.

Next, when the creation of binary data from the image sensor 26 via the comparator 44 and the like is completed, a decoding process is started to the decoding circuit 45 to perform the decoding process. When the decoding for converting the binary data into the code data is completed, the decoding result is output via the connection cable 30.

In this embodiment having such a configuration, the auxiliary light source 23-9, which consumes less power, is turned on during non-reading, and the reading light source 23-, which consumes more power than the auxiliary light source 23-9, is turned on. 1 to 23-8 are extinguished.

An interrupt occurs at a predetermined cycle, and in the interrupt processing, reading of a two-dimensional code is started by activation of imaging.

First, the auxiliary light source 23-9 is extinguished, and the reading light sources 23-1 to 23-8 are turned on. At this time, light from the light sources 23-3 to 23-6 having high directivity and high luminance is
5 and the light is diffused and reflected, and the reading cover 32
In contact with the opening 33 of a predetermined distance (focal length)
And irradiates the secondary quaternary code of the print medium approaching at the same time.

Light sources 23-1, 23-2, 23- having low directivity
Light from 7, 23-8 is irregularly reflected by the irregular reflection surface 35 and
The light is applied to the two-dimensional code while being reflected on the various codes in the reading cover 32 without passing through the irregular reflection surface 35 while being irradiated on the two-dimensional code. On the other hand, the light from the light sources 23-3 to 23-6 having a high directivity and a high brightness, the light path to the two-dimensional code of the printing medium that is in contact with or close to the opening 33 with a predetermined distance is blocked by the shielding plate 34. Since it is shielded, it is not directly irradiated on the two-dimensional code.

Accordingly, the two-dimensional code is irradiated with irregularly reflected light of light having high directivity and high luminance, and is directly and indirectly irradiated with light of low directivity and low luminance, and is uniformly illuminated. You.

Here, one frame image is captured by the image sensor 26, converted into binary data by the comparator 44, decoded by the decode circuit 45, and
The data is output to the data processing unit 45.

When the decoding by the decoding circuit 45 is completed, the reading light sources 23-1 to 23-8 are turned off and the auxiliary light source 23-9 is turned on.

FIG. 6 shows the AG at the start of reading a two-dimensional code.
3 shows a waveform of an output signal of the C circuit 42.

The time point B is a time point at which the reading light sources 23-1 to 23-8 are turned on.

Before the time point B, the auxiliary light source 23-9 is lit, so that the gain of the AGC circuit 42 is maintained at a certain level. The illuminance does not suddenly decrease as a performance,
The output level from the image sensor 26 does not decrease. Accordingly, the level of the gain of the AGC circuit 42 is maintained as it is, and at the time B, the light sources 23-1 to 23-2 for reading are read.
3-8 lights up because the increase in illuminance due to lighting of the reading light sources 23-1 to 23-8 immediately after the auxiliary light source 23-9 is extinguished is gradual, so that the output level from the image sensor 26 rises. The AGC circuit 42 also has a good responsiveness, and the output signal of the AGC circuit 42 is stabilized in a short time (at time C).

FIG. 7 shows a waveform of an output signal of the AGC circuit 42 at the start of reading of a two-dimensional code when there is no auxiliary light source 23-9.

The time point D is a time point when the reading light source is turned on. Since there is no auxiliary light source before this time point D, the gain of the AGC circuit 42 is set to the minimum level so that the output level of the AGC circuit 42 is at the low level. Is declining.

When the reading light source is turned on in such a state, the illuminance sharply increases, and the output from the image sensor 26 sharply increases. At this time, the automatic gain control function of the AGC circuit 42 has poor followability, and it takes a long time until the output signal of the AGC circuit 42 is stabilized (time E).

By providing the auxiliary light source 23-9, the reading light sources 23-1 to 23-8 do not have to be constantly turned on, so that power saving can be realized and the reading light source can be realized. It is possible to shorten the time until reading of the two-dimensional code is stabilized when is turned on.

As described above, according to the present embodiment, the light source unit 23 includes the auxiliary light source 23-9, the light sources 23-3 to 23-6 having high directivity and the high brightness, and the light source 23 having low directivity and the low brightness.
-1, 23-2, 23-7, and 23-8, and diffusely reflects light from the light sources 23-3 to 23-6 having high directivity and high brightness to come into contact with the opening 33 of the reading cover 32 or A diffuse reflection surface 35 that irradiates a two-dimensional code approached at a predetermined distance, and a shield that shields an optical path where light from a light source 23-3 to 23-6 having high directivity and high brightness directly irradiates the two-dimensional code. By providing the plate 34, it is possible to irradiate the two-dimensional code with light of uniform intensity. Therefore, the two-dimensional code can be read accurately.

In this embodiment, the frame 2
By forming the recessed portions 36 and 37 in the portion gripped by the second hand, it is possible to obtain an effect that the two-dimensional code reader 21 is easy to hold.

Further, since the trigger switch 28 is provided so as to completely fit into the recess 36, even if the two-dimensional code reader 21 is accidentally dropped, the trigger switch 2 is provided.
8 can be obtained without being turned on by a fall and not being damaged.

Further, an auxiliary light source 23-9 is provided to turn off the light sources 23-1 to 23-8 for reading and turn on the auxiliary light source 23-9 when reading is not performed. By turning off the light source 9 and turning on the reading light sources 23-1 to 23-8, power saving can be realized, and the reading light sources 23-1 to 23-8 can be realized.
The effect that a stable image signal can be obtained in a short time when turning on 23-8 can be obtained.

The present invention is not limited to this embodiment, and various modifications can be made without departing from the gist of the present invention, for example, the arrangement and fixing method of various light sources.

[0062]

As described in detail above, according to the present invention,
It is possible to provide a two-dimensional code reader that can irradiate light of uniform intensity to the two-dimensional code and can accurately read the two-dimensional code.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a schematic configuration of a two-dimensional code reader according to an embodiment of the present invention and a diagram illustrating a configuration of a light source unit.

FIG. 2 is a top view showing the two-dimensional code reader of the embodiment.

FIG. 3 is an exemplary block diagram showing a circuit configuration of a main part of the two-dimensional code reader according to the embodiment;

FIG. 4 is an exemplary view showing the flow of an interrupt generation process performed on the two-dimensional code reader of the embodiment.

FIG. 5 is an exemplary view showing the flow of an interruption process performed on the two-dimensional code reader of the embodiment.

FIG. 6 is a view showing a waveform of an output signal of an AGC circuit of the two-dimensional code reader according to the embodiment.

FIG. 7 is a diagram showing a waveform of an output signal of an AGC circuit of a two-dimensional code reader without an auxiliary light source.

FIG. 8 is a cross-sectional view illustrating a schematic configuration of a conventional two-dimensional code reader and a diagram illustrating a configuration of a light source unit.

FIG. 9 is a top view showing the conventional two-dimensional code reader.

[Explanation of symbols]

 23 light source unit 23-1, 23-2 light source with low directivity 23-3 to 23-6 light source with high directivity and high brightness 23-7, 23-8 light source with low directivity Weak light source, 23-9: auxiliary light source, 34: shielding plate, 35: diffuse reflection surface.

Claims (4)

(57) [Claims] A two-dimensional code reader for reading a two-dimensional code by irradiating a light to the two-dimensional code, receiving a reflected light of the light, and reading the two-dimensional code; A light source having a high directivity, a diffuse reflection member for irregularly reflecting light from the light source to the two-dimensional code positioned at the reading opening, and a straight line from the light source to the reading opening
A two-dimensional code reader comprising a light shielding member provided in an optical path . 2. A two-dimensional code printed on a print medium.
The two-dimensional code is irradiated with light by facing the reading opening,
Two-dimensional code that reads two-dimensional code by receiving reflected light
In the reader, the first light source with high directivity and this directivity
Low directivity combined with highly directional light source
A light source, and light from the first light source positioned at the reading opening.
And a diffuse reflection member for causing diffuse reflection to the two-dimensional code.
A two-dimensional code reader characterized by the fact that 3. The two-dimensional code reader according to claim 2,
Linear light from the light source with high directivity to the reading port
A two-dimensional code reader comprising a light shielding member provided on a road . 4. The method according to claim 1 or 2,
In the two-dimensional code reader described above, the irregular reflection member is
The secondary, which is provided inside the reading port
Former code reader.