JPH0210697Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an optical data reading device that optically reads data on a medium using a reading sensor.

[Conventional technology]

In conventional optical data reading devices that read data on a medium that exists in a wider area than the reading field of view of the reading sensor, it is necessary to correct insufficient light intensity near both ends of the irradiation range of the light source or near the ends of the condensing lens. This is done using a single shading plate.

[Problem that the invention attempts to solve]

However, with the above-mentioned conventional technology, it is difficult to correct the appropriate amount of light. Therefore, in order to accurately read data over a wide range with a uniform amount of light, it is necessary to move the light source together with the reading sensor.
Alternatively, it is necessary to install a plurality of reading sensors and light sources in parallel, which results in a complicated and large-scale configuration, and also increases cost.

The present invention was developed to solve these problems, and the purpose is to realize an optical data reading device that has a simple configuration, can perform highly accurate reading, and is inexpensive. It is.

[Means for solving problems]

In order to achieve the above-mentioned object, the present invention includes one fixed light source that can illuminate the entire data reading range in the width direction of the medium, and a light source that is placed at a position that limits the light reflected from the medium by this light source. a first shedding plate; a carriage positioned behind the first shedding plate when viewed from the medium side and supported by a guide shaft so as to be movable in the width direction of the medium; A reading sensor mounted on the carriage facing in a direction parallel to the medium, a light condensing lens mounted on the carriage so as to face the reading sensor, and a light incident on the light condensing lens on the carriage. This structure includes a second shading plate mounted at a position that limits reflected light from the medium.

[Effect]

In the present invention having the above-described configuration, the reflected light from the medium irradiated by the light source is limited by the first shading plate to make the light amount distribution uniform over the entire data reading range, and the light is focused. Since the reflected light incident on the lens can be restricted by the second shading plate and the light intensity distribution near the center and edges of the condensing lens can be made uniform, it is possible to By simply moving only the reading section including one reading sensor, condensing lens, and second shading plate, a wide range of data can be read with a uniform amount of light.

Therefore, according to this, it becomes possible to realize at low cost an optical data reading device that has a simple configuration and is capable of reading data with high accuracy.

〔Example〕

Examples will be described below with reference to the drawings.

FIG. 1 is a front view showing an embodiment of an optical data reading device according to the present invention, and FIG. 2 is a side view thereof.
In the figure, reference numeral 1 denotes a fluorescent lamp as a fixed light source, which is capable of illuminating the entire widthwise area of a medium 2, which is a data reading range, on which data to be read by a reading sensor, which will be described later, is written.

Reference numeral 3 denotes a first shading plate for correcting the amount of light irradiated by the fluorescent lamp 1, and is fixedly arranged at the rear of the fluorescent lamp 1.

A carriage 4 is movable in the width direction of the medium 2, and is slidably supported by guide shafts 5a and 5b arranged parallel to the medium 2.
This carriage 4 includes a condensing lens 6 and a medium 2.
a mirror 7 that deflects reflected light from the lens in the direction of the condensing lens 6; a second shading plate 8 that corrects aberrations of the condensing lens 6; and a reading field projected by the condensing lens 6. A CCD image sensor 9 is mounted as a reading sensor that photoelectrically converts the image of the image, and these constitute a reading section.

That is, to describe the structure in more detail, the carriage 4 is located behind the first shedding plate 3, and the CCD image sensor 9 is mounted on the carriage 4 in a direction parallel to the medium 2. has been done. Further, a condensing lens 6 is mounted on the carriage 4 so as to face the CCD image sensor 9, and a mirror 7 is mounted on the medium 2.
The second shading plate 8 is mounted on the carriage 4 at a predetermined angle so as to guide the reflected light from the mirror 7 to the condensing lens 6. It is mounted on the carriage 4 so as to limit the reflected light incident on the carriage 4.

Next, the operation of the above-described configuration will be explained. As is well known, the light intensity distribution of the fluorescent lamp 1 is large in the center and small in both ends, so when the medium 2 is irradiated with this light source 1, the reflected light from the medium 2 is It is limited by the aging plate 3 and corrected so that the light amount distribution is uniform over the entire reading range.

In addition, the light intensity distribution near the center and edges of the condensing lens 6 is such that the center has a large amount of light and the edges have a small amount of light, so the second shading plate 8
By limiting the reflected light incident on the mirror 7, the light intensity distribution near the center and end portions of the condensing lens 6 is corrected to be uniform.

Therefore, by the carriage 4 of the reading section
No matter where you move it in the data reading range wider than the field of view of the CCD image sensor 9, the first
The light amount correction performed by the second shading plate 3 and the second shading plate 8 makes it possible to keep the output level of the CCD image sensor 9 constant at all times.

In addition, in the embodiment described above, the carriage 4
The means for sliding the slider along the guide shafts 5a, 5b can be achieved by means of a well-known drive mechanism, for example a belt or a wire running parallel to the guide shafts 5a, 5b, a part of which is fixed to the carriage 4, and a pulse A mechanism configured to pull the carriage 4 by transmitting an operation by a motor or the like to the wire or belt may be used.

In addition, in the embodiment described above, as a reading sensor
Although the CCD image sensor 9 is used, the present invention is not limited to this, and a reading sensor made of a photodiode array or the like may be used, for example.

[Effect of idea]

As explained above, the present invention uses a first shading plate that corrects the light intensity distribution of the reflected light from the medium, and a second shading plate that corrects the light intensity distribution of the reflected light incident on the condensing lens. A shading plate is mounted on a carriage that moves the reading sensor, and the second shading plate not only absorbs uneven illuminance distribution caused by the condensing lens, but also absorbs reflections from the reading range on the document. Since the light can also be made uniform by the first shading plate, data in a data reading range wider than the field of view of the reading sensor can be read with a uniform amount of light with a simple configuration.
This has the effect of realizing a data reading device that can read data at low cost and with high precision, and can be used to read data such as forms where the position of the read data is not constant.

[Brief explanation of the drawing]

Figure 1 is a front view showing one embodiment of the present invention;
The figure is a side view thereof. 1: Fluorescent lamp, 2: Medium, 3: First shading plate, 4: Carriage, 5a, 5b: Guide shaft, 6: Condensing lens, 7: Mirror,
8: Second shading plate, 9: CCD
image sensor.

Claims (1)

[Claims for Utility Model Registration] An optical data reading device that reads data written on a medium in a range wider than the reading field of view of a reading sensor, which illuminates the entire data reading range in the width direction of the medium. a first shading plate disposed at a position that limits light reflected from the medium by the light source; and the first shading plate when viewed from the medium side. a carriage located at the rear of the medium and supported by a guide shaft so as to be movable in the width direction of the medium; a reading sensor mounted on the carriage in a direction parallel to the medium; A condensing lens mounted on the carriage to face each other; and a second shedding plate mounted on the carriage at a position that limits reflected light from a medium that is incident on the condensing lens. The reflected light from the medium irradiated by the light source is limited by a first shading plate to make the light amount distribution uniform over the entire data reading range, and the reflected light incident on the condenser lens is is limited by a second shading plate,
An optical data reading device characterized by equalizing the light intensity distribution near the center and edges of a condensing lens.