JPH09231304A - Code reader - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a code reader capable of sufficiently correcting uneven illumination and having high reading performance at a low cost. SOLUTION: The code reader has at least an illumination part for irradiating a code optically readably recorded in a recording medium 30 with light, a light receiving part for receiving reflected light from the code and an optical system 14 for leading the reflected light to the light receiving part. The illumination part has an illuminating substrate 26 mounting LEDs 18 on its surface and the board 26 is arranged on the periphery of a lens frame 22 for holding the optical system 14. An illuminating diffusion plate 28 is arranged between the substrate 26 and the code. The plate 28 has concaves in the optical axis direction of the LED 18.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention includes, for example, so-called audio information such as voice and music, video information obtained from cameras and video equipment, digital code data obtained from personal computers and word processors, and the like. The present invention relates to a code reading device for optically reading the code pattern from an information recording medium such as paper on which multimedia information is recorded as an optically readable two-dimensional code pattern.

[0002]

2. Description of the Related Art Conventionally, various media such as magnetic tapes and optical disks have been known as media for recording voice, music and the like. However, even if these media are made in large quantities, the unit price is somewhat expensive, and a large space is required for storage. Furthermore, if it is necessary to hand over the recorded audio medium to another person at a remote location, it takes time and effort to mail it or take it directly. There was also. Also, other than audio information, video information obtained from cameras, video equipment, etc., and digital code data obtained from personal computers, word processors, etc.
The same applies to the so-called multimedia information as a whole including the above.

As a means to deal with such a problem, Japanese Patent Laid-Open No. 6-231466 discloses at least one of audio information, video information and digital code data.
A plurality of dots are arranged two-dimensionally as image information, that is, coded information, which can be used for facsimile transmission of multimedia information including information and can be reproduced in large quantities at low cost.
A system for recording on an information recording medium such as paper in the form of a dimensional code pattern and a system for reproducing the same are disclosed.

The information reproducing apparatus disclosed in this publication adopts a pen-type code reading device as a reading unit for optically reading a dot code on a recording medium, and holds such a code reading device by hand. Then, the code is read by manually scanning the recording medium along the recorded dot code.

By the way, as a structure of the above-mentioned pen-type code reading device, for example, an optical reading device such as a bar code as disclosed in Japanese Patent Laid-Open No. 6-162241 can be applied. is there.

In the code reading device disclosed in this publication, the light reaches the code by once condensing the dispersed light emitted from each point light source using a convex lens in the illumination unit composed of a plurality of LEDs. Irradiation light with less illumination unevenness is radiated to the cord by reducing the waste of the illumination light (reduction of light energy per unit solid angle emitted from the point light source) until it is turned on, and then passing it through the semi-transparent diffusion plate. I am trying to do it. That is, the diverging light from the point light source is purposely focused once and then dispersed again.

This is because the light-receiving portion is near the light-emitting portion, so that when light is emitted from the light-emitting portion as it is, leaked light from the light-emitting portion wraps around to the light-receiving portion, such as flare. In order to deal with the possibility that the light emission part is far from the code, and the brightness of the illumination illuminating the code itself becomes dark, we collect it once with a convex lens. I try to shine.
When the light is focused in this way, uneven illumination occurs. Therefore, a diffuser plate is used immediately before the code to cancel the uneven illumination.

In such usage, the diffusion plate has the following features: Lighting unevenness caused by the directivity of the LED itself (the center is bright and the periphery is dark, etc.), 2. By arranging a plurality of LEDs, lighting unevenness can be created because the lights emitted from the LEDs overlap. Performance is required to reduce three types of uneven illumination, namely regular reflection (a subject's shining light) that occurs when light with sharp directivity enters the light receiving portion.

In order to satisfy the above performance, a diffusion plate having a considerably high diffusivity must be used. Therefore, in the code reading device disclosed in the above-mentioned Japanese Patent Laid-Open No. Hei 6-162241, a translucent diffusion is required. It uses a plate.

[0010]

However, in the case of using the translucent diffuser plate as described above, the unevenness of illumination is caused by increasing the diffusivity of the diffuser plate (using a material having a high light diffusivity). Although it can be reduced, generally, the light diffusion rate and the light transmission rate are contradictory to each other. Therefore, if the light diffusion rate is increased, the light transmission rate is lowered, the illumination light amount is reduced, and the code reading performance is deteriorated.

If the number of LEDs is increased to maintain the amount of illumination light, the cost will increase. further,
In the code reading device disclosed in Japanese Patent Laid-Open No. 6-162241, the illumination unit is tilted, and the illumination light is emitted to the intended place (the angle at which the light is accurately reflected by the light receiving unit).
The accuracy of mounting the lighting on the exterior is required, and the mounting shape becomes complicated.

Further, since the light emitting portion and the light receiving portion are close to each other and there is no light shielding member, the direct light from the LED or the light reflected by the surface of the exterior, the lens for condensing illumination, etc. enters the light receiving portion and the reading performance is improved. Is likely to deteriorate.

Therefore, with the structure disclosed in the above publication, it is difficult to sufficiently correct the unevenness of illumination, and it is difficult to provide the user with a code reading device having high reading performance at low cost.

The present invention has been made in view of the above points, and an object of the present invention is to provide a code reading apparatus which can correct uneven illumination sufficiently, is low in cost, and has high reading performance.

[0015]

In order to achieve the above-mentioned object, a code reading device according to the invention of claim 1 is
An illumination unit that irradiates light to a code that is optically readable recorded on a recording medium, a light receiving unit that receives reflected light from the code, and a lens unit that guides reflected light to the light receiving unit, The substrate member on which the light emitting member of the illumination unit is mounted is located around the frame member that holds the lens group of the lens unit,
An illuminating optical member having a concave surface in the optical axis direction of the light emitting member is arranged between the substrate member and the code irradiated with light by the illuminating section.

That is, according to the code reading apparatus of the first aspect of the invention, the light from the LED as the light emitting member is made larger than the directivity angle of the LED itself by the concave lens effect of the illumination optical member, Lighting unevenness can be eliminated.

According to a second aspect of the present invention, there is provided a code reading apparatus which illuminates a code recorded on a recording medium so that the code can be read optically, and receives reflected light from the code. A substrate member including a light receiving portion and a lens portion that guides reflected light to the light receiving portion, and a substrate member on which the light emitting member of the illumination portion is mounted is located around a frame member that holds a lens group of the lens portion, and the substrate An illumination diffusing member having a peripheral thickness reduced with respect to the thickness of the light emitting member at the center of the optical axis is disposed between the member and the cord irradiated with light by the illuminating unit.

That is, according to the code reader of the second aspect of the present invention, by making the central thickness of the illuminating diffusing member thicker than the peripheral thickness, the diffusivity and absorption of light at the center from the periphery can be achieved. By increasing the size, it is possible to attenuate the light near the axis of the LED as the light emitting member that causes regular reflection.

According to the third aspect of the present invention, there is provided a code reading device which illuminates a code optically readable on a recording medium and illuminates the code, and receives reflected light from the code. A substrate member including a light receiving portion and a lens portion that guides reflected light to the light receiving portion, and a substrate member on which the light emitting member of the illumination portion is mounted is located on an outer peripheral portion of a frame member that holds a lens group of the lens portion, The light emitting point of the light emitting member is held at a position away from the cord from the tip of the frame member.

That is, according to the third aspect of the code reading apparatus of the present invention, the unevenness of illumination in the central portion and the peripheral portion is caused by kicking the light entering the central portion of the subject from the LED as the light emitting member by the frame member. Can be eliminated (prevent brightening of the center).

[0021]

Embodiments of the present invention will be described below with reference to the drawings. In addition, in the following description, the same reference numerals are given to the same configurations in the respective embodiments.

Here, the code reading apparatus in the following embodiments manually scans a code pattern recorded on a recording medium (not shown) so that the code pattern can be optically read by the optical system. The present invention relates to a structure of a pen-type code reading device which is read via a device such as a dot code disclosed in Japanese Patent Laid-Open No. 6-231466 and a patent application by the applicant of the present invention (Japanese Patent Application No. 6-313698). ) Is a particularly preferred form for performing dot code reading as described in (1), but for example reading a two-dimensional bar code recorded little in the first direction and many in the second direction orthogonal thereto. Of course, the present invention is also applicable to the structure of a bar code reading device for performing the above, and the structure of a character reader that scans the characters of a book or newspaper line by line and reads the characters. That.

FIG. 1A is an enlarged view showing the internal structure of the shaft tip portion of the code reading device according to the first embodiment of the present invention, and FIG. 2 shows the operating state of the code reading device. FIG. 3 is a cross-sectional view showing the configuration of this code reading device.

In the present embodiment, the casing of the code reading device has a barrel main portion 1 as a grip portion held by the operator.
0 and a barrel tip portion 12 provided at the tip of the barrel main portion 10 with a predetermined inclination angle with respect to the axial direction.

An optical system (lens) 14, an area sensor (CCD) 16 for converting the imaged light from the optical system 14 into an electric signal and outputting the electric signal, and a code pattern are irradiated in the barrel tip portion 12. And an LED 18 for illumination are provided. Here, the area sensor 16 includes the barrel main part 1
It is arranged on the lower surface side of the board extension portion 20A located inside the barrel tip portion 12 integrally provided with the electrical equipment board 20 arranged on the 0 side, and is attached to the lens frame 22 supporting the optical system 14. The light from the optical system 14 is guided by the mirror 24. The illumination LEDs 18 are arranged on a ring-shaped illumination substrate 26 attached to the lens frame 22 on the same circle at predetermined intervals, and an illumination diffusion plate 28 is provided on the front surface thereof. Installed.

A sliding contact portion 32, which is in sliding contact with the recording medium surface 30, is attached to the tip end portion of the barrel tip portion 12 as described above, and a reflecting plate 34 is arranged in the sliding contact portion 32.
The sliding contact surface of the sliding contact portion 32 is a surface orthogonal to the optical axis of the optical system 14, and the sliding contact portion 32 rubs the recording medium when scanning the code pattern. Therefore, in order not to damage the recording medium and the code pattern at that time, the material of the tip end portion is formed by using a self-lubricating crystalline resin such as polyacetal, PBS, nylon or Teflon.

The reason why the barrel tip portion 12 is inclined at a predetermined angle is as follows. That is, in order to capture an image of the code pattern without causing one-sided blurring or distortion, the tip of the code reading device is brought into close contact with the recording medium and the area sensor 16 is directly faced to the recording medium. Therefore, it is necessary to stand the code reader straight on the recording medium. However, considering the manual scanning of the code pattern, it is very inconvenient to move the code reading device in the upright position. Therefore, even if the tip of the code reading device is tilted and the optical system 14 and the area sensor 16 are housed therein, and the operator holds the shaft cylinder main part 10 as shown in FIG. The barrel tip portion 12 can be erected straight on the recording medium surface 30, and an image can be captured without blurring or distortion. Also, due to this inclination, during scanning,
Since the operator's hand deviates from the code pattern to be scanned, it becomes easy to see the code pattern to be scanned. The predetermined inclination angle is preferably about 20 to 30 degrees in consideration of both operability and portability.

On the other hand, in the main body 10 of the shaft, a plurality of cylindrical batteries as the power source 36, two in this case, are housed and arranged along the axial direction. Then, the electrical component board 20 for mounting the electrical component (IC) 40 is provided on the axial cylinder main portion upper part 38 side in the axial cylinder main portion which is the side opposite to the inclined side of the axial cylinder main portion 12 with respect to the axial cylinder main portion 10. The power source (battery) 36 is accommodated and arranged along the axial direction on the lower side of the main part of the barrel, and the power source lid 42 covers the power source (battery) 36.

A read start switch 44 for instructing the start of code reading by the code reader is attached to the electrical board 20. This mounting position corresponds to the area sensor 1 arranged on the board extension portion 20A.
It is disposed behind 6 and on the upper surface side of the electrical equipment substrate 20. Then, between the area sensor 16 arranged in the board extension portion 20A and the reading start switch 44 arranged on the upper surface side of the electric equipment board 20, the electric equipment board 2 is provided.
A substrate support portion 46 for supporting 0 is provided. Further, another switch having a different function from the reading start switch 44, that is, the main switch 48 and the output signal adjusting section (for example, a volume when the output signal is an audio signal) 50.
Is disposed in the rear portion of the main barrel portion 10.

Reference numeral 52 is a power source segment, 54 is a cover of the reading start switch 44, 56 is an external output jack, and 58 is an output signal cord. In the code reading device having such a configuration, the illumination diffusion plate 28 is
For example, it is formed of transparent acrylic or polycarbonate, and has a concave shape on both sides as shown in FIG. By making both surfaces concave in this way, the light emitted from the point light source (light emitting point 18A) of the illumination LED 18 is originally caused by the concave lens effect of the diffusion plate 28 as shown in FIG. 1 (B). The LED 18 is irradiated at a wider angle than the directivity of the LED 18, and thus uneven illumination can be reduced.

In addition to the effect of diffusing light by the function of the concave lens, the diffusing plate 28 has the following effect.
For example, when the material itself is a resin material in which a diffusing agent or the like is kneaded, it is possible to further improve the light diffusion effect together with the diffusion by the material itself.

As a modification of this, as shown in FIG. 1C, the resin 18B encapsulating the LED 18 itself has a concave lens effect and a diffusion effect by kneading a diffusing agent. Can obtain a similar function.

Next, a second embodiment of the present invention will be described. The present embodiment mainly relates to the shape of the diffuser plate for preventing regular reflection due to illumination.

That is, the LED emission point 18A and the recording medium surface 3
0 (code) and the diffusion plate 28 for illumination,
As shown in FIG. 4A, the light emitting point 18A of the LED 18
The thickness is approximately on the axis, and the thickness becomes thinner as the distance from the axis increases. Since the material of the diffuser plate 28 itself has diffusivity, the central portion is thick, so that the central portion has a low light transmittance and the peripheral portion is thin. Increases light transmittance. Therefore, as a result, the most effective LED for specular reflection
It is possible to attenuate the light substantially on the axis of the light emitting point 18A, and at the same time, sufficiently illuminate the code on the recording medium surface 30 without causing the light amount itself to extremely decrease by allowing the peripheral portion to pass the light. You can

As a modification thereof, the resin 1 for sealing the bare chip of the LED 18 mounted on the illumination board 26 is used.
The same effect can be obtained by forming 8B so that the thickness on the axis of the light emitting point is thicker and the thickness becomes thinner as the distance from the axis increases, as shown in FIG. 4B.

The uneven thickness of the diffuser plate 28 is, as shown in FIG. 4C, convex on both sides in the optical axis direction and convex on the upper side in the optical axis direction. A shape in which the lower side is convex with respect to the direction is conceivable, but in any shape, since the thickness of the center is thick, the same effect as above can be obtained. Further, by forming the diffusion plate 28 into a multi-body structure, for example, a three-body structure as shown in FIG. 4D, each shape as shown in FIG. 4C can be arbitrarily set. Therefore, the diffusivity can be easily adjusted.

As another form of the diffusion plate 28, as shown in FIG. 4E, the surface facing the light emitting surface side of the LED 18 may be formed as a half mirror 28A. In such a case, the light reflected by the half mirror 28A is condensed and reflected on the recording medium surface 30 (code) side by the reflection plate 34, so that the code can be irradiated without loss in brightness. Also, the half mirror 28
The light transmitted through A is first attenuated at the stage of passing through the half mirror 28A and further attenuated at the stage of passing through the diffuser plate 28, so that it affects the specular reflection of the LED emission point 18A substantially on the axis. With respect to light, there will be considerable attenuation. However, since the light reflected by the half mirror 28A is irradiated onto the code by the reflection plate 34 as described above, the total brightness on the code is hardly attenuated.

Next, another embodiment for reducing uneven illumination will be described as a third embodiment of the present invention. Now, when the illumination board 26 is at the position A shown in FIG.
The light emitting point 18 A of the recording medium surface 3 is higher than that of the end surface of the lens frame 22.
0, that is, on the side opposite to the code, and as a result, the lens frame 22 kicks the light emitted by the LED 18. Therefore, in such a case, a substantially flat light distribution characteristic can be obtained as shown in FIG.

When the illumination board 26 is further separated from the cord at the position A, for example, when the illumination board 26 is arranged at the position B shown in FIG. 5A, the illumination is kicked by the lens frame 22. Since the amount of light increases, that is, the light going to the center is kicked by the lens frame 22, so the peripheral area has the same brightness as in the case of the A position, but the center becomes dark, as shown in FIG. 6B. Thus, the light distribution characteristic is such that the center is depressed.

On the other hand, when the position of the illumination substrate 26 is at the position C shown in FIG. 5B, the light emitting point 18A is on the recording medium surface 30 side with respect to the end surface of the lens frame 22. The frame 22 does not kick the illumination light, and in such a case, the light distribution characteristic is such that the center is raised, as shown in FIG.

Therefore, if the illumination board 26 and the lens frame 22 are lightly press-fitted and the position of the illumination board 26 can be changed, the unevenness of the illumination is intended by appropriately setting the position of the illumination board 26. It becomes possible to control it physically.

On the other hand, the optical system 14, that is, the lens, has a physical characteristic that the periphery is darker than the center, as shown in FIG. Therefore, when the light distribution characteristic curve in the case where the LED 18 shown in FIG. 6B is at the B position is overlapped with the curve of the peripheral extinction characteristic of such a lens, the peripheral extinction characteristic of the lens is reduced. Since the surroundings are bright, the bright and dark parts cancel each other out, and as a result, the light entering the area sensor 16, that is, the light receiving part is illuminated as shown in (E) of FIG. It will be even. In this way, by setting the illumination substrate 26 at the optimum position, the reflected light from the cord can be taken into the light receiving portion as light without illumination unevenness.

Further, since the light from the LED 18 is kicked by the lens frame 22 as a result, the overall brightness itself of the illumination on the code surface is attenuated by the amount kicked by the lens frame 22.
Therefore, the end surface of the lens frame 22, that is, the surface on which the light of the LED 18 strikes is made a reflecting surface 22A by a reflection process such as sputtering of aluminum, and the light kicked by the lens frame 22 is reflected to the cord side. The light attenuation can be reduced and the brightness on the cord can be secured.

Also, for example, even when the light amount value around the optical system 14 is changed by changing the design of the lens, it can be dealt with by adjusting the position of the illumination substrate 26 to a position corresponding to it. It will be possible.

As the position adjusting means for the illumination board 26, in addition to the method for determining the position of the illumination board 26 by lightly press-fitting the illumination board 26 and the lens frame 22 as described above, the illumination board is fitted with a fitting screw or the like. Various methods such as adjusting the position of 26 can be considered.

Next, a fourth embodiment of the present invention will be described. LED 18 mounted on ring-shaped illumination board 26
As shown in FIG. 7A, in the case of using a general LED with a cannonball-shaped lead, as shown in FIG. 7B, the overlapping portion of the LEDs, that is, the middle portion, The light distribution characteristic is such that the light amount drops. As a method generally used to prevent such a drop in light amount, as shown in (C) of the same figure, the LED is tilted so that the optical axes of the LEDs intersect with the target object distance, and the middle illumination is provided. It is known to eliminate unevenness. Alternatively, as shown in (D) of the figure, there is also known a method of arranging a diffusion plate having high diffusivity on the front surface of the LED to crush the uneven illumination itself.

However, in the former method, the LEDs have to be mounted in a tilted manner, which imposes design restrictions on the LED fixing method, arrangement, etc., and as a result, the assembled lighting unit itself becomes large. There is also a problem that high mounting accuracy is required. In the case of the latter method, since the diffuser plate has a high diffusibility, the unevenness of illumination is eliminated, but the phenomenon that the amount of illumination light is reduced occurs.

Therefore, in this embodiment, as shown in FIG. 8A, the LE having the light emitting point 18A, that is, the light emitting chip, is eccentrically arranged with respect to the central axis of the shell type package.
D18C, for example, VS665 L manufactured by Optrans
Use ED. Such an eccentric arrangement LED 18C has a symmetrical light distribution characteristic in the Y direction having no eccentricity, as shown in FIG. As shown in (C) of the figure, it has a light distribution characteristic in which the brightness in the direction opposite to the eccentric direction is increased.

However, such an eccentric arrangement LED 18 is used.
As shown in FIG. 9, C is mounted on the illuminating board 26 so that the eccentric direction of the light emitting point (chip) 18A is on the outside of the ring-shaped illuminating board 26, so that it is opposite to the eccentric side of the chip. Since the light energy on the side, that is, the brightness becomes brighter,
As the brightness of each overlaps, as shown in the figure,
It is possible to obtain illumination light with little illumination unevenness.

Of course, conversely to this, as shown in FIG. 10, the light emitting point 18A is formed in the central direction of the ring-shaped illumination board 26.
When the eccentric position is brought, it is possible to obtain light distribution characteristics such that the center is raised, or the light emitting point 1
Desired light distribution characteristics can be obtained by alternately arranging the positions of 8A in the center direction and the outer direction.

As described above, by constructing the illumination unit using the eccentric LED 18C, it is possible to easily correct the illumination unevenness without tilting the LED or using a diffuser plate having extremely strong diffusivity. .

Next, a fifth embodiment of the present invention will be described. The present embodiment relates to a method of compensating for the light amount drop due to the inclusion of the diffusion plate 28 and the like.

That is, as shown in FIGS. 11A and 11B, a dummy pattern 62 is provided by copper foil or coating on a portion of the illumination board 26 other than the conductive pattern 60 for mounting the LED 18. , The light reflected from the surface 30 of the recording medium, that is, the code, is transmitted to the illumination substrate 26 again.
It is configured to be reflected back to the cord side with. With such a configuration, it becomes possible to efficiently irradiate the cord side with useless light that has conventionally penetrated through the illumination substrate 26 and passed through to the back side.

By soldering the dummy pattern 62, light can be reflected more efficiently than when the copper foil itself remains. In addition to using the dummy pattern 62 as the reflecting member, a similar effect can be obtained by applying white paint such as silk printing to a portion other than the portion where the LED 18 is mounted. Further, from the viewpoint of reducing the cost, the lighting board 26 is made of a milky white board material such as glass epoxy.
Since the substrate material itself also reflects light by forming, it is possible to reflect light again to the code side without providing the dummy pattern 62 or white paint.

In this way, by reflecting the reflected light from the code again on the illumination board 26, the utilization efficiency of the illumination light can be improved. Although the present invention has been described based on the above embodiments, the present invention is not limited to the above embodiments, and various modifications and applications are possible within the scope of the gist of the present invention. Here, the summary of the present invention is as follows.

(1) An illuminating section for irradiating a code optically readable on a recording medium with light, a light receiving section for receiving reflected light from the code, and guiding the reflected light to the light receiving section. A substrate member including a lens unit and mounting the light emitting member of the illumination unit is located around a frame member that holds the lens group of the lens unit, and is irradiated with light by the substrate member and the illumination unit. The code reading device is characterized in that an illumination optical member having a concave surface in the optical axis direction of the light emitting member is disposed between the code reading device and the code.

That is, the light from the LED as the light emitting member can be made larger than the directivity angle of the LED itself by the concave lens effect of the optical member for illumination, and the uneven illumination can be eliminated.

(2) The code reading device according to (1), wherein the illumination optical member is a concave lens.
That is, the light from the LED can be made larger than the directivity angle of the LED itself by the concave lens, and uneven illumination can be eliminated.

(3) The code reader according to (1), wherein the illumination optical member is a diffusive material. That is, it is possible to increase the effect of eliminating uneven illumination by providing the illumination optical member with diffusivity.

(4) The code reader according to (2) or (3), wherein the light emitting member is an LED and the illumination optical member is an LED chip sealing member.

That is, by providing the LED chip sealing member with a lens effect or diffusibility, it is possible to reduce uneven illumination and the number of parts. (5) An illumination unit that irradiates a code recorded on the recording medium in an optically readable manner with light, a light receiving unit that receives reflected light from the code, and a lens unit that guides the reflected light to the light receiving unit. A substrate member on which the light emitting member of the illuminating unit is mounted is located around a frame member that holds the lens group of the lens unit, and the code is illuminated by the substrate member and the illuminating unit. The code reading device is characterized in that an illuminating diffusing member having a peripheral thickness smaller than the thickness of the light emitting member at the center of the optical axis is disposed between

That is, by making the central thickness of the illuminating diffusion member thicker than the peripheral thickness, the diffusion and absorption of light at the center from the periphery is increased, and the LED axis as a light emitting member that causes specular reflection. Light near the top can be attenuated.

(6) The code reader according to (5), wherein the light emitting member is an LED and the illuminating diffusion member is an LED chip sealing member.

That is, by providing the LED chip sealing member with the effect of extinguishing the light in the vicinity of the LED axis, it is possible to reduce uneven illumination and reduce the number of parts. (7) The code reading device according to (5), wherein the lighting diffusion member has a central thickness that is thicker on one side or both sides in the optical axis direction with respect to the peripheral thickness.

That is, one side or both sides can be selected depending on the required light attenuation amount. (8) The code reading device according to (5), wherein the lighting diffusion member is made of a plurality of components.

That is, the thickness of the center can be easily adjusted by combining the parts, and the required light extinction amount can be easily selected. (9) The code reader according to (5), wherein the lighting diffusion member has a half mirror on the light emitting member side.

That is, specular reflection can be reduced by having the effect of extinguishing the light transmitted through the illuminating diffusion member and extinguishing the light in the vicinity of the LED axis as the light emitting member. Further, by reflecting the light reflected by the half mirror to the code side by a reflecting plate or the like provided around the light emitting member, the amount of light attenuated by the lighting diffusion member can be adjusted.

(10) The code reading device according to (5), wherein the illumination diffusion member is a diffusive material. That is, the effect of reducing uneven illumination can be increased by providing the diffusing member for illumination itself with diffusivity.

(11) An illuminating section for irradiating the code recorded on the recording medium so as to be optically readable, a light receiving section for receiving the reflected light from the code, and guiding the reflected light to the light receiving section. A substrate member having a lens portion and mounting a light emitting member of the illumination portion is located on an outer peripheral portion of a frame member that holds a lens group of the lens portion, and is positioned away from the cord from the tip of the frame member. A code reading device, which holds the light emitting member so that a light emitting point of the light emitting member is located at the position.

That is, it is possible to eliminate the uneven illumination of the central portion and the peripheral portion (prevent brightening of the central portion) by kicking the light entering the central portion of the subject from the LED as the light emitting member with the frame member. it can.

(12) The code reader according to (11), wherein the outer peripheral portion of the frame member is subjected to a reflection treatment. That is, the amount of illumination light can be increased by reflecting the light kicked by the frame member obliquely forward at the outer peripheral portion of the frame.

(13) The code reader according to (11), wherein the substrate member is positionally adjustable with respect to the frame member. That is, the amount of light kicked by the frame member (illumination unevenness caused by the positional relationship between the light-emitting member and the frame member) can be easily adjusted, and the peripheral light reduction of the lens and the illumination unevenness caused by the reflection plate and the like can be easily offset.

(14) An illuminating section for irradiating a code optically readable recorded on a recording medium, a light receiving section for receiving the reflected light from the code, and guiding the reflected light to the light receiving section. A light emitting member of the lighting unit is an LED having a shell-shaped outer shape, and a light emitting chip of the LED is mounted eccentrically with respect to the center of the package. Code reading device.

That is, by eccentricizing the light emitting chip with respect to the LED package, the directivity of the LED shifts to the side opposite to the chip shift direction with respect to the package center.
You can control uneven lighting.

(15) The cord according to (14), wherein the light emitting member has an eccentric position of the light emitting member arranged radially outward or inward with respect to the optical axis of the lens portion. Reader.

That is, the uneven illumination can be operated. (16) An illuminating section that irradiates light onto a code that is optically readable recorded on a recording medium, a light receiving section that receives reflected light from the code, and a lens section that guides the reflected light to the light receiving section. The code reading device is characterized in that the substrate member for mounting the light emitting member of the illumination section is provided with a pattern for mounting the light emitting member and a reflecting member.

That is, it is possible to reduce the leakage of illumination light to the rear of the substrate (increase the reflection by the substrate) and increase the irradiation light amount to the subject. (17) The code reader according to (16), wherein the reflection member has a copper foil left on a portion other than the pattern for mounting the light emitting member.

That is, the copper foil can prevent light leakage to the back surface of the substrate. (18) The code reading device according to (17), wherein the copper foil left on the portion other than the pattern is one side or both sides.

That is, the copper foil can prevent light leakage to the back surface of the substrate. (19) The code reading device according to (17), wherein the copper foil left on a portion of the substrate member other than the pattern on the code side is soldered.

In other words, the reflectance can be increased by soldering as compared with the copper foil alone. (20) The code reading device according to (16), wherein the reflecting member is coated.

That is, the coating can prevent light from leaking to the back surface of the substrate and can reflect light that is about to leak. (21) The code reader according to (20), wherein the coating is on one side or both sides.

That is, the coating can prevent light from leaking to the back surface of the substrate and can reflect light that is about to leak. (22) The code reading device according to (16), wherein the substrate member is made of a milky white material and resist printing is not performed. That is, by omitting the resist (green), light can be reflected on the milky white substrate material surface.

[0083]

As described in detail above, according to the present invention,
It is possible to provide a code reading device that can sufficiently correct the unevenness of illumination, is low in cost, and has high reading performance.

[Brief description of drawings]

FIG. 1A is an enlarged view showing an internal structure of a shaft tip portion of a code reading device according to a first embodiment of the present invention; FIG.
FIGS. 3A and 3B are diagrams showing a configuration of an illumination optical member for explaining a characteristic part of the first embodiment.

FIG. 2 is a diagram showing an operating state of the code reading device according to the first embodiment.

FIG. 3 is a cross-sectional view showing the configuration of the code reading device according to the first embodiment.

FIGS. 4A to 4E are diagrams showing a configuration of a lighting diffusion member for explaining a characteristic part of a second embodiment of the present invention. FIGS.

FIGS. 5A and 5B are diagrams showing the positional relationship of LED light emitting points for explaining the characteristic part of the third embodiment of the present invention. FIGS.

FIGS. 6A to 6E are light distribution characteristic diagrams for explaining the features of the third embodiment.

7A is an external view of a general LED, and FIG. 7B is L
FIG. 3 is a diagram showing the arrangement relationship of EDs and the light distribution characteristics thereof, and FIGS. 6 (C) and (D) are diagrams showing the general arrangement relationship of LEDs for eliminating uneven illumination.

8A is an external view of an eccentric arrangement LED used in the fourth embodiment of the present invention, and FIGS. 8B and 8C are Y and Y of the eccentric arrangement LED of FIG. 8A, respectively. It is a figure which shows the light distribution characteristic of a X direction.

9A and 9B are diagrams showing an arrangement relationship and a light distribution characteristic when the eccentric arrangement LED of FIG. 8A is used.

FIG. 10 is a plan view of an illumination board for explaining a modification of the fourth embodiment.

11A and 11B are a cross-sectional view and a perspective view of an illumination board for explaining a characteristic part of a fifth embodiment of the present invention.

[Explanation of symbols]

 14 Optical System (Lens) 18 LED for Illumination 18A Light Emitting Point (Chip) 18B LED Encapsulating Resin 18C Eccentric LED 22 Mirror Frame 22A Reflecting Surface 26 Illuminating Board 28 Illuminating Diffuser 28A Half Mirror 30 Recording Medium Surface (Code) 34 Reflector 60 Conductive pattern 62 Dummy pattern

Claims (3)

[Claims] 1. A lighting unit for irradiating a code recorded on a recording medium so as to be optically readable, a light receiving unit for receiving reflected light from the code, and a lens for guiding the reflected light to the light receiving unit. And a substrate member on which the light emitting member of the illumination unit is mounted is located around a frame member that holds the lens group of the lens unit, and is irradiated with light by the substrate member and the illumination unit. A code reading device, wherein an illumination optical member having a concave surface in the optical axis direction of the light emitting member is arranged between the code and the code. 2. A lighting unit for irradiating a code recorded on a recording medium in an optically readable manner with light, a light receiving unit for receiving reflected light from the code, and a lens for guiding the reflected light to the light receiving unit. And a substrate member on which the light emitting member of the illumination unit is mounted is located around a frame member that holds the lens group of the lens unit, and is irradiated with light by the substrate member and the illumination unit. The code reading device is characterized in that an illuminating diffusion member having a peripheral thickness smaller than a thickness of an optical axis center of the light emitting member is arranged between the code and the code. 3. A lighting unit for irradiating a code recorded on a recording medium so as to be optically readable, a light receiving unit for receiving reflected light from the code, and a lens for guiding the reflected light to the light receiving unit. And a substrate member on which the light emitting member of the illumination unit is mounted is located on an outer peripheral portion of a frame member that holds the lens group of the lens unit, and is located at a position away from the cord from the tip of the frame member. A code reading device, which holds the light emitting member so that a light emitting point of the light emitting member is positioned.