JPH09190489A - Information reader - Google Patents

Abstract

PROBLEM TO BE SOLVED: To always maintain an optimum radiating effect and to make a driving state visible at a low cost and with ease by providing a reflection means reflecting reading laser beam to an optical component and a reflection means driving means. SOLUTION: A head part 40 builds-in a metallic base 51 supporting only laser diode(LD) and a light source 20 and a platelike printed circuit board 1 integrally fixed with this metallic base 51, and an optical component excepting for the light source 20, namely a reading optical system, is supported on this printed circuit board 1. Then a photodetector 25 is arranged at a position within the optical path range of a reflected light reflected from an optical patter 44a and not-interrupting the reflected light and receives a reflected light converged by a projecting spherical surface mirror part 15b to convert to a prescribed electrical signal. In addition a mirror driving device 3 rotates a mirror 15 by a prescribed angle so as to scan the reading laser beam reflected from a flat surface mirror part 15a along the optical pattern 44a.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an information reading device for optically reading information from an optical pattern such as a bar code in which predetermined information is coded and printed.

[0002]

2. Description of the Related Art Conventionally, an information reading apparatus has been developed which optically reads information from an optical pattern such as a bar code in which predetermined information is patterned. Here, for example, a barcode is a coding pattern printed on a label that can be attached to each article in order to identify the type of each article, and specifically, a plurality of barcodes having various widths. It is a coding pattern in which predetermined information is coded and recorded by a combination of a bar of a book and a space between these bars.

In a general information reading device, a coded pattern of a bar code is optically read by detecting a change in an optical characteristic of reflected light reflected from a bar code irradiated with light, and the coded pattern of the bar code is read individually. The type of item will be identified.

For example, in the information reading apparatus shown in FIG. 4 (hereinafter referred to as the first conventional art), all the optical members, that is, the position adjusting mechanism 61, emit laser light on one printed circuit board 60. A laser light source 62 whose emission direction is adjustable, a scanning mirror 64 which reflects the laser light emitted from this laser light source 62 in the direction of a target barcode (not shown), and this scanning mirror 64 are integrated with each other. A concave spherical condensing mirror 68 that is formed and condenses the return light from the bar code on the photo sensor 66 is arranged. The concave spherical condensing mirror 68 integrally formed with the scanning mirror 64 has a base end. Is attached to the tip of an arm 72 connected to the drive device 70. Also, the arm 72
The tip of the arm 72 is supported by an elastically deformable leaf spring 74, and the tip of the arm 72 is elastically swung by driving the driving device 70. The laser light source 62 applied to the first conventional technique is provided with a radiator 76 for preventing excessive heat generation.

According to this structure, when the laser light is emitted from the laser light source 62 in the state where the information reading device is directed toward the target barcode, the laser light is scanned by the scanning mirror 64. Is reflected in the direction. At this time, the drive device 70 causes the arm 72 to move.
When the tip of is scanned, the laser light reflected from the scanning mirror 64 is scanned on the bar code. Then, the return light reflected from the barcode is condensed on the photosensor 66 by the concave spherical condensing mirror 68, and after being converted into an electric signal corresponding to the change of the optical characteristics,
It is read as barcode information by a signal processing circuit (not shown).

Further, for example, an information reading apparatus disclosed in Japanese Patent Laid-Open No. 6-236450 (hereinafter referred to as a second prior art) emits a laser light source among the optical members and a laser light source. A movable mirror that scans a laser beam on a target bar code is mounted on a metal base that has high mounting accuracy and good heat dissipation. With such a configuration, it is not necessary to adjust the optical axis of the laser beam, and the heat dissipation effect can be improved, so that it can be used at high temperatures.

[0007]

However, in the information reading apparatus of the first prior art, since all the optical members are arranged on the printed circuit board 60, the laser light from the laser light source 62 is particularly reliable. So that the laser light source 62 and the scanning mirror 64 are irradiated onto the scanning mirror 64.
It is necessary to work to align the optical axes between and. For this reason,
Since the position adjusting mechanism 61 is separately required, not only the number of parts of the apparatus increases and the manufacturing cost increases, but also a lot of time is wasted in the position adjusting work.

Further, the printed circuit board 60 is usually as thin as about 2 mm or less, and the material thereof is made of epoxy resin, bake or the like, and it is difficult to maintain flatness as compared with metal or the like.

When such a printed circuit board 60 is used, even if the optical axis adjustment is completed once, the printed circuit board 6 is used.
When the 0 is attached to a predetermined device, the printed circuit board 6
There is a case where 0 is deformed and the optical axes are displaced from each other. In such a case, the laser light is removed from the scanning mirror 64, which makes it difficult to scan the target bar code.

In this case, for example, by increasing the size of the scanning mirror 64, it is possible to eliminate the above-mentioned adverse effects to some extent, but the weight of the scanning mirror 64 increases,
The scanning speed of the laser light becomes slow. Further, because the size of the scanning mirror 64 is increased, the area of the concave spherical condensing mirror 68 becomes smaller, so that the amount of return light condensed by the photosensor 66 becomes smaller. It may be difficult to read.

Further, since the printed circuit board 60 used in the first conventional technique is composed of a thermal non-conductor,
For example, a radiator 76 attached to the laser light source 62 is required, but since only a small radiator corresponding to the size of the printed circuit board 60 can be used, it is difficult to maintain the optimum heat radiation effect. There is.

Further, since the laser light source 62 is weak against heat and its function is impaired when the temperature rises, the laser light source 62 is controlled so that the light emission stop limiter works when the temperature exceeds a certain temperature. Therefore, for example, in a place where the outside air temperature is high, such as outdoors in summer, the immediate limiter operates,
There are certain restrictions on the use of the information reading device.

On the other hand, in the information reading apparatus of the second prior art, since the driving device for driving the movable mirror by the magnetic action is attached to the printed circuit board which is separate from the metal base, it is possible to individually confirm the operation. Can not. Further, there is a problem in the device configuration that it becomes difficult to confirm the operating state of the movable mirror from the outside after the printed circuit board and the metal base are assembled.

In the second prior art, the movable mirror and the driving device need to be separated to some extent in consideration of the positional deviation at the time of assembling the printed circuit board and the metal base. According to this structure, not only the alignment of the movable mirror and the light receiving element becomes difficult, but also the magnetic action of the driving device becomes difficult to be transmitted to the movable mirror. For this reason, in order to scan the movable mirror at high speed, a large amount of energy must be supplied to the driving device, which increases power consumption. Further, in order to exert the optimum magnetic action on the movable mirror, the magnet of the driving device has to be large in size, so that the device becomes large and the manufacturing cost also rises.

Further, since the second conventional technique uses a large-sized light receiving element which can directly receive the return light from the bar code without condensing it, this light receiving element is provided with a bar code. In addition to the return light of, the reflected light reflected from other parts is also taken in. For this reason, the reading accuracy of the bar code is lowered, and the manufacturing cost of the apparatus is increased due to the use of the large-sized light receiving element.

The present invention has been made to solve such a problem, and an object thereof is to always be able to maintain an optimum heat radiation effect without being affected by the use environment, and at the same time, to an optical pattern with low power. It is an object of the present invention to provide a compact and low-priced information reading device capable of reading information with high accuracy and in a short time by performing high-speed scanning and capable of easily visually confirming a driving state.

[0017]

In order to achieve such an object, the present invention provides a metal member supporting only a light source capable of emitting a reading laser beam and an optical pattern in which predetermined information is patterned. And a printed circuit board provided separately from the metal member, which supports an optical component capable of scanning the reading laser beam to read predetermined information. At least a reflecting means for reflecting the reading laser light emitted from the light source and a reflecting means driving device for scanning the reading laser light reflected by the reflecting means along the optical pattern are provided.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An information reading device according to an embodiment of the present invention will be described below with reference to the accompanying drawings. As shown in FIG. 3A, the information reading apparatus according to the present embodiment has a head unit 40 that incorporates a reading optical system described later.
And the head portion 40 so as to support the head portion 40.
And a handle portion 42 that can be held by one hand.

As shown in FIGS. 1A and 1B, the head section 40 includes a light source capable of emitting a reading laser beam, that is, a laser diode (hereinafter, simply referred to as LD), and a light source including a lens and a diaphragm. A metal member for supporting only 20, that is, a metal base 51, and a flat printed circuit board 1 integrally fixed to the metal base 51 are built in, and on the printed circuit board 1, An optical component other than the light source 20, that is, a reading optical system is supported.

As shown in FIGS. 1 and 3, the reading optical system includes a plane mirror portion 15a which reflects the reading laser light emitted from the light source 20 in the direction of the target optical pattern 44a (see FIG. 3A). And a mirror 15 having a concave spherical mirror portion 15b formed integrally with the plane mirror portion 15a and condensing the reflected light reflected from the optical pattern 44a in a predetermined direction, and an optical path of the reflected light reflected from the optical pattern 44a. A photodetector 25 (hereinafter, simply referred to as PD) that is arranged in a region that is inside the range and that does not block reflected light, receives the reflected light collected by the concave spherical mirror portion 15b, and converts the reflected light into a predetermined electric signal. ), The mirror 15 is rotated by a predetermined angle so that the reading laser light reflected from the flat mirror portion 15a is scanned along the optical pattern 44a. And a mirror driving unit 3.

Such a reading optical system is connected to a circuit formed on the printed circuit board 1, and the printed circuit board 1 has a signal processing circuit (not shown) for processing the electric signal converted by the PD 25. ) Is provided. The LD is a printed circuit board 1 via a cable (not shown) such as a flexible printed circuit board.
It is connected to the LD driving circuit (not shown) formed in the above.

The optical path range of the reflected light reflected from the optical pattern 44a is indicated by the symbol A in FIG. Further, as the optical pattern 44a applied to the present embodiment, for example, a bar code coded and printed on the seal 44 that can be attached to various articles (not shown), or a direct code for various articles is used. The printed barcode is applicable. Such a bar code 44a (this bar code is a subordinate concept of the above-mentioned optical pattern 44a, so the same reference numerals are used) means, for example, a plurality of bars having various widths (in the drawing, This is a coded pattern in which predetermined information is recorded by a combination of the spaces (intervals) between these bars, which are not shown by reference numerals.

In the present embodiment, the light source 20 is provided in an area outside the optical path range A of the reflected light, and the light source 20
The reading laser light emitted from the emission point 20a is irradiated onto the plane mirror portion 15a.

The light source 20 applied to this embodiment is a printed circuit board 1 that supports optical members other than the light source 20, that is, the mirror 15, the mirror driving device 3, the PD 25, and the like.
It is supported on a metal base 51 which is separated from the above and has a heat dissipation effect and a shield effect.

The light source 20 is attached to a U-shaped groove 52 (see FIG. 1B) formed in a metal base 51 made of a material such as aluminum die cast or zinc die cast. After the light source 20 is positioned in the U-shaped groove 52 by the screw 53, the light source 20 is firmly attached to the metal base 51 by an adhesive (not shown).
In the present embodiment, the U-shaped groove 52 is formed on the metal base 51.
However, it is also possible to form a tunnel-shaped hole and mount the light source 20 in this hole.

Further, the metal base 51 and the printed circuit board 1 are integrated by screws 55 after the optical axis alignment between the light source 20 and the reading optical system is completed (after the optical adjustment is completed). Fixed. In this case, a pedestal 54 is arranged between the metal base 51 and the printed circuit board 1 in order to avoid interference with various circuits formed on the printed circuit board 1. The pedestal 54 is preferably as compact as possible so that the size between the metal base 51 and the printed circuit board 1 can be reduced to make the device compact.

As a method of fixing the metal base 51 and the printed circuit board 1, for example, a positioning pin is used instead of the screw 55, and after the printed circuit board 1 is set on the positioning pin, a case (not shown) is provided. The printed circuit board 1 may be pressed and fixed toward the metal base 51 by the protruding pressing pin. In this case, the metal base 51
The printed circuit board 1 and the printed circuit board 1 are pressed and fixed to each other by the pressing force of the pressing pin that acts on the printed circuit board 1 when the case is covered with the printed circuit board 1 in a state where they are positioned relative to each other.

As shown in FIG. 1 (b), the metal base 51 has a device mounting hole 51a formed therein, and a predetermined mounting jig (not shown) is mounted in the device mounting hole 51a. By doing so, the entire information reading apparatus of the present embodiment can be fixed to a predetermined main body base 57 (see FIG. 1C). As another fixing method, as shown in FIG. 1C, a device mounting hole 1b is formed in the printed circuit board 1, and the device mounting hole 1b is formed.
It is also possible to fix the entire information reading device of the present embodiment to a predetermined main body base 57 by attaching a predetermined mounting jig (not shown) to the.

Further, the PD 25 is provided inside the optical path range A of the reflected light, at a position where the reflected light is not blocked, and at a position avoiding the optical path of the laser light reflected from the plane mirror portion 15a, that is, It is provided at a position below the optical path.

Such a PD 25 has a light receiving surface 25.
A filter 30 that allows only laser light having a predetermined frequency component to pass through is provided on a. As a result, outside light such as an interior light or sunlight having a frequency component other than the frequency component of the reflected light reflected from the optical pattern 44a is
The light receiving surface 25 of the PD 25 is blocked by the filter 30.
Does not reach a. Therefore, the PD 25 has the optical pattern 4
It is possible to highly accurately output an electric signal corresponding to the optical characteristics of the reflected light reflected from 4a.

The mirror driving device 3 includes a driving unit 4 and a movable unit 5.
And at a predetermined angle about a rotation axis B that is rotatably provided substantially at the center thereof and is orthogonal to the surface of the printed circuit board 1 (that is, orthogonal to the optical axis of the reading laser beam). It is configured to be rotatable.

The movable part 5 is configured to be rotatable about the rotation axis B by a predetermined angle by driving the drive part 4. A mirror 15 is attached to the tip of the movable part 5. ing. As a result, the mirror 15 is moved to the movable part 5
With the rotation of, the rotation is about the rotation axis B within a predetermined angle range.

In the present embodiment, the plane mirror portion 15a and the concave spherical mirror portion 15b are integrally formed.
The concave spherical mirror portion 15b may be fixed so that only the plane mirror portion 15a is driven.

The drive unit 4 may be configured by combining the permanent magnet 6 and the coil 7, or may be configured to be directly driven by a motor (not shown). Specifically, a current is applied to the coil 7 at a predetermined timing to magnetize the coil 7, and the magnetic action acting between the coil 7 and the permanent magnet 6 at this time is used to rotate the movable portion 5. It becomes possible to reciprocate about the moving axis B by a predetermined angle.

The plane mirror portion 15a of the mirror 15 has its reflecting surface extending parallel to the rotation axis B and emitted from the light source 20 in the initial state where the mirror 15 is stationary. The reading laser light is positioned so as to be emitted orthogonally to the edge portion 1a of the printed circuit board 1. Therefore, the directional optical path of the reading laser light output from the emission point 20a of the light source 20 via the plane mirror portion 15a is positioned on the plane parallel to the printed circuit board 1.

Further, the concave spherical mirror portion 15b receives the reflected light from the optical pattern 44a on the light receiving surface 25a of the PD 25 which is provided in the inner region of the optical path range A of the reflected light and at a position where the reflected light is not blocked. It is positioned to collect light. Further, the light receiving surface 25a of the PD 25 is positioned so as to be orthogonal to the optical axis extending from the concave spherical mirror portion 15b.

According to this structure, as shown in FIGS. 1 and 3, the reading operator first uses one hand (not shown).
While holding the handle portion 42, the head portion 40 is directed toward the target barcode 44a. Then, a switch (not shown) provided on the handle portion 42 is turned on to drive the reading optical system in the head portion 40.

As a result, the reading laser light emitted from the emission point 20a of the light source 20 is reflected from the plane mirror portion 15a and emitted as the scanning beam 46 from the head portion 42 in the direction of the bar code 44a.

At this time, when the mirror driving device 3 is driven to reciprocally rotate the mirror 15 about the rotation axis B by a predetermined angle, the scanning beam 46 reflected from the plane mirror portion 15a.
Oscillates within a predetermined range as the plane mirror section 15a rotates.

In the present embodiment, since the rotation axis B is arranged orthogonal to the optical axis of the reading laser light, the scanning beam 46 reflected from the plane mirror portion 15a is along the bar code 44a. As a result of being scanned, the scanning line 48 draws a locus in a direction orthogonal to the individual bars forming the bar code 44a. In this case, the bar code 44a
Similarly, the scan line 48 is
A locus will be drawn in a direction orthogonal to the individual bars forming a.

At this time, the reflected light reflected from the bar code 44a scanned by the scanning beam 46 is reflected by the mirror 1
It is taken in by the concave spherical mirror portion 15b of No. 5 and is condensed in the PD25 direction by this concave spherical mirror portion 15b.

Since the filter 30 is provided on the light receiving surface 25a of the PD 25, only the reflected light reflected from the bar code 44a is condensed on the light receiving surface 25a. The reflected light focused on the light receiving surface 25a is converted by the PD 25 into an electric signal corresponding to its optical characteristics, and then read as bar code information by a signal processing circuit (not shown).

In the above description of the operation, the head unit 4
Switch 0 after pointing 0 toward the bar code 44a
The operation was performed, but the present invention is not limited to this.
It is also possible to aim the barcode 44a in a state where the switch ON operation is performed and the scanning beam 46 is emitted. In this case, different barcodes 44a can be continuously scanned with the scanning beam 46 emitted.
Also, other devices such as POS (point-of-sale information management)
Scanning can also be started by a trigger signal or a control signal from a connection device such as a terminal device or a host computer.

According to the information reading device of the present embodiment, the following effects can be obtained. That is, the emission point 2 of the light source 20
By defining the directional optical path of the laser light for reading output from 0a through the plane mirror section 15a on a plane parallel to the printed circuit board 1, miniaturization of the information reading device in the height direction is achieved. , PD25 with barcode 4
By providing the position inside the optical path range A of the reflected light from 4a and not blocking the reflected light, miniaturization of the information reading device in the width direction is achieved. As a result, the entire device can be made compact.

When making the information reading device compact,
For example, as shown in FIG. 2, when the PD 25 is arranged in an area outside the optical path range A of the reflected light, the normal line H of the mirror 15 and the scanning beam 4 are reflected in order to reflect the reflected light in the PD 25 direction.
It is necessary to tilt the mirror 15 by an angle θ formed by 6 and 6.

In this case, the concave spherical mirror portion 1 of the mirror 15
The effective area for collecting the reflected light by 5b is reduced to the area obtained by multiplying the original area of the concave spherical mirror 15b by cos θ. As a result, particularly when scanning a distant bar code 44a (the bar code 44a is not shown in the figure, the bar code 44a of FIG. 3A is used instead), the concave spherical mirror section 15b is used. Since the amount of reflected light that can be received is reduced, not only the optical reading performance is significantly impaired, but also the scanning distance is shortened, and the reading accuracy is also reduced.

However, according to the present embodiment, the configuration as shown in FIGS. 1 and 3 makes it possible to make the concave spherical mirror portion 15b directly face the reflected light. It is possible to effectively use the effective area of 15b.

Further, according to this embodiment, the mirror 15
The scanning beam 46 reflected from the plane mirror portion 15a is arranged as a bar code by arranging the rotation axis B of the scanning axis B orthogonal to the optical axis of the laser light emitted from the light source 20 (that is, orthogonal to the surface of the substrate 1). It becomes possible to scan along the line 44a, and the scanning line 48 draws a locus in a direction orthogonal to the individual bars forming the bar code 44a. This is similar to the case where the barcode 44a becomes long, the scanning line 48 is
A locus is drawn in a direction orthogonal to the individual bars forming the bar code 44a.

As a result, it is possible to provide a compact information reading apparatus which can reliably scan the optical pattern and read the information with high accuracy without being affected by the arrangement state of the optical pattern. .

Further, according to the present embodiment, since only the light source 20 is supported on the metal base 51 having a heat radiation effect and a shield effect which are separate from the printed circuit board 1, the use environment is affected. It is possible to maintain the optimum heat dissipation effect without being disturbed, and it is possible to read the information with high accuracy and in a short time by performing high-speed scanning of the optical pattern with low power, and to visually check the drive status easily. It is possible to provide a possible information reading device.

[0051]

According to the present invention, it is possible to always maintain the optimum heat radiation effect without being affected by the use environment, and
It is possible to provide a compact, low-priced information reading device capable of reading information with high accuracy and in a short time by performing high-speed scanning of an optical pattern with low power and easily visually confirming a driving state.

[Brief description of the drawings]

FIG. 1A is a plan view showing a configuration of a reading optical system incorporated in an optical head section of an information reading device according to an embodiment of the present invention, and FIG. 1B is a sectional view thereof.

FIG. 2 is a diagram for explaining a problem when a PD is provided in an area outside the optical path range of reflected light in the optical head unit shown in FIG.

3A is a perspective view showing a state in which a barcode is scanned by the scanning beam emitted from the reading optical system shown in FIG. 1, and FIG. 3B is a trajectory of a scanning line on the barcode. FIG.

FIG. 4 is a perspective view schematically showing a configuration of a conventional information reading device.

[Explanation of symbols]

 1 Printed Circuit Board 3 Mirror Driving Device 15 Mirror 15a Flat Mirror 15b Concave Spherical Mirror 20 Light Source 25 Photo Detector 51 Metal Base

Claims (3)

[Claims] 1. A metal member supporting only a light source capable of emitting a reading laser beam, and an optical device capable of scanning the reading laser beam along an optical pattern in which the predetermined information is patterned to read the predetermined information. A printed circuit board that supports the component and is provided separately from the metal member, wherein the optical component reflects the reading laser light emitted from the light source, An information reading device comprising at least a reflecting device driving device for scanning the reading laser light reflected by the reflecting device along the optical pattern. 2. The information reading device according to claim 1, wherein the entire information reading device is configured to be fixed to a predetermined portion by the metal member. 3. The information reading apparatus according to claim 1, wherein the entire information reading apparatus is configured to be fixed to a predetermined portion by the printed circuit board.