JP5169569B2 - Light source device for reading - Google Patents

Description

  The present invention relates to a reading light source device for irradiating a reading surface such as a barcode with light.

Conventionally, address information written on a mail piece is read by OCR, then the address information is converted into code information such as a bar code, and the code information is printed on the mail piece. There is known a technique that enables sorting of postal items only by providing a simple bar code reader without having to provide an OCR (see, for example, Patent Document 1).
For barcodes printed on postal items, ink containing fluorescent or phosphorescent materials is used for the beauty of postal items, and it is very difficult for human eyes to see under white light. It becomes visible by irradiating. A black light using a fluorescent tube as a light source is used for the light source device for irradiating ultraviolet rays.
JP-A-10-258256

When an ultraviolet LED is used as the light source in place of the fluorescent tube, the ultraviolet LED generally has a lower light amount than the fluorescent tube, and therefore there may be cases where irradiation sufficient for reading a barcode is not possible. Therefore, in order to irradiate the barcode with sufficient ultraviolet light, it is conceivable to collect light emitted from the ultraviolet LED on the barcode reading surface using a condensing optical system.
However, if light is simply collected on the barcode reading surface, the distribution of the amount of irradiation light on the reading surface will be non-uniform and the entire barcode will not be visible uniformly. There is a problem that occurs.
In order to avoid this problem, it is only necessary to accurately arrange the ultraviolet LED and the condensing optical system at a position designed so that the distribution of the irradiation light quantity on the reading surface is uniform. Deteriorate.
The present invention has been made in view of the above-described circumstances, and provides a reading light source device that can easily assemble a light source device having a uniform distribution of the amount of irradiation light on a reading surface while using an LED as a light source. For the purpose.

To achieve the above object, the present invention is, in a housing provided with an irradiation opening on a surface facing the reading surface, LED board ultraviolet LED is provided, and the ultraviolet LED is provided on the LED substrate is reflector for directing the reading surface emission light through the irradiation opening holding respectively, a pair of holders positioned on opposite sides of the irradiation opening, in each of the holders, the LED substrate, and e the reflector holder By tightening together, the ultraviolet LED and the reflecting mirror of the LED substrate are positioned at a position where the light irradiated from both sides of the irradiation opening intersects in the vicinity of the reading surface and the distribution of the irradiation light amount becomes uniform. There is provided a reading light source device characterized in that the reading light source device can be taken out.

  Further, the present invention provides the reading light source device according to the present invention, wherein a plurality of the LED boards are connected to each other, the LEDs are arranged in a row over the LED boards, and each of the LED boards is arranged. Is characterized in that the LEDs are arranged in close contact with the adjacent LED substrate.

  Further, the present invention provides the reading light source device according to the present invention, wherein the holder includes a holding portion that holds the LED substrate, and each of the upper and lower end portions of the holding portion is bent at one or both of them. And the holder is fixed in a state where the respective bent portions are in surface contact with the inner surface of the casing.

  According to the present invention, in the reading light source device according to the present invention, the reflecting surface of the reflecting mirror is formed as a concave surface that covers the emitting surface of the LED.

  According to the present invention, the holder provided in the housing is fastened together with the LED substrate on which the LED is provided and the reflecting mirror that collects the light emitted from the LED on the reading surface through the irradiation opening. Since the LED and the reflecting mirror can be positioned with respect to the irradiation opening, the LED substrate and the reflecting mirror can be positioned at a position where the distribution of the irradiation light amount on the reading surface becomes uniform simply by assembling the LED substrate and the reflecting mirror to the holder. Therefore, assembly becomes easy.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a diagram schematically showing a configuration of a mail reading system 1 according to the present embodiment. As shown in this figure, the mail reading system 1 irradiates the barcode printed invisible on the upper surface 7 of the mail 5 with ultraviolet light while transporting the mail 5 along the transport surface 3. In this system, the barcode is visualized, and the barcode is photographed and readable.
Specifically, the postal matter reading system 1 is arranged to face the upstream side transport device 9 and the downstream side transport device 11 that transport the postal matter 5 at a position spaced from the transport surface 3, and is placed on the upper surface 7 of the postal matter 5 with ultraviolet rays. A reading light source device 17 for irradiating light and a line camera 19 for photographing an ultraviolet irradiation place by the reading light source device 17 are provided.

Further, in the housing 21 of the reading light source device 17, an irradiation opening 25 for irradiating ultraviolet light is formed on a facing surface 23 facing the upper surface 7 of the postal matter 5. The irradiation opening 25 is arranged so that the shortest distance to the upper surface 7 of the mail piece 5 is a distance L1 (for example, 6 mm) or more.
Further, the ultraviolet light emitted from the irradiation opening 25 is irradiated to the irradiation range R (FIG. 6) over the distance L <b> 2 along the transport surface 3 immediately below the irradiation opening 25.
The line camera 19 is arranged on a vertical line 33 that passes through the irradiation opening 25, and photographs the barcode printed on the upper surface 7 of the mail piece 5 through the irradiation opening 25.

FIG. 2 is a view showing a plane and a side surface of the reading light source device 17, and FIG. 3 is a bottom view of the reading light source device 17. FIG. 4 is a perspective view of the reading light source device 17 as seen from the right side.
The housing 21 of the reading light source device 17 is formed in a box shape extending in the direction orthogonal to the transport direction, that is, in the width direction of the postal matter 5 and having an upper surface opened. A photographing unit including the line camera 19 is attached to the opening 34 on the upper surface.
A control board 37 is disposed at one end 35 of the housing 21, and various circuits, connectors, and switches are provided on the control board 37.
As shown in FIG. 3, a slit-like opening is formed as the irradiation opening 25 on the facing surface 23 constituting the bottom surface of the casing 21, and the irradiation opening 25 is covered with an ultraviolet transmissive front glass 39. Yes.

As shown in FIGS. 2 and 4, a plurality (seven in this embodiment) of light source units 41 are arranged in a line on both sides of the irradiation opening 25.
As shown in FIG. 4, the light source unit 41 includes an LED substrate 43 on which an ultraviolet LED 49 is mounted, a reflecting mirror 45 that collects light emitted from the ultraviolet LED 49 on the upper surface 7 of the mail piece 5 through the irradiation opening 25, and these LEDs. A holder 47 for holding the substrate 43 and the reflecting mirror 45, and an LED drive circuit board 51 on which a drive circuit for driving the ultraviolet LED 49 is mounted.
The LED drive circuit board 51 is supported and fixed by a bar-like support member 53 in a state where a part of the LED drive circuit board 51 overlaps the upper side of the LED board 43, and the LED drive circuit board 51 in the height direction of the reading light source device 17. The amount of protrusion is suppressed.

  The holder 47 is formed of a highly heat conductive material such as aluminum, and includes a plate-like holding portion 55 on which the LED substrate 43 is placed. The upper end portion and the lower end portion of the holding portion 55 are bent. Bent portions 57 and 59 are formed. When the holder 47 is assembled to the housing 21, the bent portions 57 and 59 of the holder 47 are in contact with the inner side surface and the bottom surface of the housing 21, thereby causing the ultraviolet LED 49 to generate heat. Heat is transferred to the casing 21 through 59.

  As shown in the conceptual diagram of FIG. 5, a plurality of ultraviolet LEDs 49 are arranged in a row on the LED substrate 43 of the light source unit 41, and the ultraviolet LEDs 49 are connected to each light source unit 41 by connecting the light source units 41. It will be arrange | positioned in a row over. In each light source unit 41, the arrangement | positioning space | interval of ultraviolet LED49 is narrowly arranged so that the both ends 50 of ultraviolet LED49 arrange | positioned in this row are narrowed. As a result, even if a predetermined gap 54 is generated between the adjacent ultraviolet LEDs 49 at the connecting portion 52 between the light source units 41, a decrease in the amount of light in the gap 54 is suppressed, and the light quantity distribution has a uniform line shape. A light source is obtained.

Each of the ultraviolet LEDs 49 emits ultraviolet rays having a spectrum having a peak at a wavelength of 365 nm, for example. The upper surface is formed as a light emitting surface, and the optical axis of the emitted light is substantially perpendicular to the mounting surface of the LED substrate 43. Arranged in the direction.
As shown in FIG. 4, the reflecting mirror 45 is configured to extend to a position where the reflecting surface 45 </ b> A covers the light emitting surface of the ultraviolet LED 49. As a result, most of the light emitted from the ultraviolet LED 49 is incident on and reflected by the reflecting surface 45A, so that the amount of light directed to the upper surface 7 of the postal matter 5 increases, and even the ultraviolet LED 49 having a small light emission amount is sufficiently irradiated. The amount of light can be obtained.
However, if the distribution of the amount of irradiation light on the upper surface 7 of the postal matter 5 is not uniform, an unclear portion is generated in the captured image of the barcode, which may affect the reading of the barcode. Therefore, in the present embodiment, the distribution of the irradiation light amount is made uniform, and this configuration will be described in detail below.

FIG. 6 is a diagram schematically showing light emitted from the light source unit 41.
The light source units 41 arranged on both sides of the irradiation opening 25 are set so as to form an irradiation range R in which the amount of irradiation light is uniform immediately below the irradiation opening 25 at a distance L1. The irradiation range R is set so that its width W (corresponding to the distance L2 shown in FIG. 1) is larger than the photographing range of the line camera 19, and the irradiation range R is set so as to correspond to the reading of the postal matter 5 with different thickness. It has a depth D (3 mm in this embodiment). The work upper limit, which is the upper limit position of the depth D, corresponds to the upper limit position of the upper surface 7 of the postal matter 5, and the work lower limit corresponds to the lower limit position of the upper surface 7 of the postal matter 5.

In order to configure such an irradiation range R, it is necessary to appropriately perform the shape and arrangement of the reflecting mirror 45 and the arrangement of the ultraviolet LED 49, and the light reflected by the reflecting mirror 45 is condensed at one point. If so, the illuminance is not uniform in the irradiation range R having the width W and the depth D as described above, and the amount of light is not the same, so that the light reflected by the reflecting surface 45A has a certain extent of spread. It is necessary to make it so that it becomes a light beam. Further, as described above, the reflecting surface 45A of the reflecting mirror 45 needs to increase the amount of irradiation light as a shape that sufficiently covers the ultraviolet LED 49. Furthermore, it is necessary that the arrangement interval E of the reflecting mirrors 45 facing each other with the irradiation opening 25 interposed therebetween is larger than the width W of the irradiation range R so that photographing with the line camera 19 is not hindered.
In addition to this, the irradiation opening 25 needs to be formed with a width of the opening such that the light reflected by the reflecting mirror 45 is irradiated without waste over the irradiation range R of the width W.

  In order to satisfy these conditions, in this embodiment, the reflecting surface 45A of the reflecting mirror 45 that covers the light emitting surface of the ultraviolet LED 49 does not collect the emitted light of the ultraviolet LED 49 in the irradiation range R, but the irradiation range R. It is formed in a shape that irradiates the whole. Thereby, a uniform light quantity distribution in the irradiation range R is obtained. Further, in the present embodiment, the light source units 41 on both sides of the irradiation opening 25 intersect each other with the irradiation light in the irradiation range R, thereby realizing irradiation with uniform light amount distribution and no illuminance unevenness.

In addition, the light emitted from the ultraviolet LED 49 in the vertical direction of the LED substrate 43 is reflected by the reflecting mirror 45 and travels toward the irradiation range R. At this time, as shown in FIG. As the angle θ is increased and the direction of the reflected light 65 emitted from the reflecting mirror 45 approaches the vertical direction, the depth D in the irradiation range R can be increased.
However, if the inclination angle θ is increased too much, the arrangement interval E between the opposing reflecting mirrors 45 becomes small. As described above, the arrangement interval E needs to be larger than the width W of the irradiation range R. As a result, the reflecting surface 45A of the reflecting mirror 45 is made small, and the lower end 45B of the reflecting surface 45A is opposed to the opposing surface 45A. It is necessary to suppress the amount extending to the reflecting mirror 45 side, but if so, the amount of light reflected by the reflecting surface 45A is reduced, and the amount of light in the irradiation range R is reduced.
On the contrary, although the lower end 45B of the reflecting surface 45A can increase the amount of light reflected by the reflecting surface 45A by increasing the amount extending to the reflecting mirror 45 facing the reflecting surface 45A, In order to make the arrangement interval E of the opposing reflecting mirrors 45 larger than the width W of the irradiation range R, it is necessary to reduce the inclination angle θ, and a desired depth D cannot be obtained.

  Therefore, in the present embodiment, the positions of the ultraviolet LED 49 and the reflection surface 45A with respect to the irradiation range R (irradiation opening 25) are defined, and the shape of the reflection surface 45A that can obtain a uniform light amount distribution in the irradiation range R, and the LED Within the range of the tilt angle θ of the substrate 43, the depth D of the irradiation range R is greater than or equal to a desired value, and the arrangement interval E of the opposing reflecting mirrors 45 is larger than the width W of the irradiation range R. The shape of the reflecting surface 45A and the installation angle θ of the LED substrate 43 are defined so that the condition is satisfied.

As shown in FIG. 4, the bent portion 59 on the lower end side of the holder 47 is bent at the inclination angle θ, and when the holder 47 is attached to the housing 21, the holding portion 55 is bent at the inclination angle θ. Tilt. The LED substrate 43 and the reflecting mirror 45 are held by the holding portion 55 of the holder 47 so that they are held at the inclination angle θ.
As described above, in order to obtain a substantially uniform light amount distribution in the irradiation range R, in addition to the inclination angle θ, the positions of the ultraviolet LED 49 and the reflection surface 45A with respect to the irradiation range R are important, and they are shifted to these positions. If this occurs, a substantially uniform light amount distribution in the irradiation range R cannot be obtained.

In the present embodiment, as shown in FIG. 4, the LED substrate 43 and the reflecting mirror 45 are fastened and fixed to the holder 47 with a fastening spiral 60. And by this joint fastening, the relative position of the LED substrate 43 (ultraviolet LED 49) and the reflecting mirror 45 (reflecting surface 45A) is positioned, and the attachment position to these holders 47 is irradiated in the irradiation range R. It is configured to be positioned at a position where the light quantity distribution is made uniform.
The light source units 41 arranged on both sides of the irradiation opening 25 are similarly configured. That is, in each light source unit 41, the LED substrate 43 and the reflecting mirror 45 are fastened together with the holder 47, so that the ultraviolet LED 49 and the reflecting mirror 45 intersect with each other in the irradiation range R. However, it is configured to be positioned at a position where the distribution of the irradiation light amount is made uniform.

  As described above, in this embodiment, the LED substrate 43 provided with the ultraviolet LED 49 and the reflecting mirror 45 are fastened together with the holder 47 so that the ultraviolet LED 49 and the reflecting mirror 45 are distributed in the irradiation amount R in the irradiation range R. Since the LED substrate 43 and the reflecting mirror 45 are simply assembled to the holder 47, the distribution of the amount of irradiation light in the irradiation range R becomes uniform, so that assembly is easy. Become.

  In particular, according to the present embodiment, the light source units 41 are respectively arranged on both sides of the irradiation opening 25, and in each light source unit 41, the LED substrate 43 and the reflecting mirror 45 are fastened together with the holder 47, thereby Since the LED 49 and the reflecting mirror 45 are configured to be positioned at positions where the light from the respective light source units 41 intersects in the irradiation range R and the distribution of the amount of irradiation light is uniform, illuminance unevenness in the irradiation range R is suppressed. A light source having a uniform irradiation light amount and a large irradiation light amount can be easily assembled.

  Further, in the present embodiment, the ultraviolet light LEDs 49 are arranged on the LED substrates 43 so that the connecting portions 52 of the adjacent light source units 41 to the LED substrates 43 are densely arranged, so that the light amount distribution is distributed along the arrangement direction of the ultraviolet LEDs 49. A uniform line-shaped light source can be obtained.

Furthermore, according to the present embodiment, the holder 47 is formed with the bent portions 57 and 59 at the upper and lower end portions of the holding portion 55 that holds the LED substrate 43, respectively. The holder 47 is fixed while being in surface contact with the inner surface of the body 21. With this configuration, the heat generated by the ultraviolet LED 49 provided on the LED substrate 43 is transferred to the housing 21 through the two bent portions 57 and 59, so that good heat dissipation is obtained.
In addition, it replaces with the structure which forms the bending parts 57 and 59 in each of the upper-and-lower-ends part of the holding | maintenance part 55, As a structure which forms the bending part 57 or the bending part 59 only in either one of an upper-lower end part Also good.

  Further, according to the present embodiment, since the reflecting surface 45A of the reflecting mirror 45 is formed in a concave surface that covers the radiation surface of the ultraviolet LED 49, much of the light emitted by the ultraviolet LED 49 is irradiated toward the irradiation range R, The amount of light in the irradiation range R can be increased.

  It should be noted that the above-described embodiment is merely an aspect of the present invention, and can be arbitrarily modified and applied within the scope of the present invention.

It is a figure which shows typically the structure of the mail reading system which concerns on embodiment of this invention. It is a figure which shows the plane and side surface of a light source device for reading. It is a bottom view of the light source device for reading. It is the perspective view which looked at the light source device for reading from the right side. It is a schematic diagram which shows the arrangement | sequence of the ultraviolet LED on the LED substrate of a light source unit. It is a figure which shows typically the light which a light source unit radiates | emits.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Postal matter reading system 5 Postal matter 17 Reading light source device 19 Line camera 21 Case 25 Irradiation opening 39 Front glass 41 Light source unit 43 LED board 45 Reflecting mirror 45A Reflecting surface 47 Holder 49 Ultraviolet LED
51 LED drive circuit board 52 articulated part 55 holding part 57, 59 bent part 60 spiral 65 reflected light 17 reading light source device D depth E arrangement interval R irradiation range W width

Claims (4)

In a housing with an irradiation opening on the surface facing the reading surface,
An LED substrate provided with an ultraviolet LED and a reflecting mirror provided on the LED substrate for directing light emitted by the ultraviolet LED toward the reading surface through the irradiation opening are respectively positioned and positioned on both sides of the irradiation opening. A pair of holders,
Each holder, the LED substrate, and by co-fastening the reflector to the Holder, near the ultraviolet LED and the reflecting mirror, the radiation sides the reading surface light irradiated from the opening of the LED substrate A reading light source device characterized in that it can be positioned at a position where the distribution of the amount of irradiation light is uniform while intersecting at . A plurality of the LED boards are connected to each other, the LEDs are arranged in a row over the LED boards, and the LED is placed on each of the LED boards, and the connection portion with the adjacent LED board is densely arranged. The reading light source device according to claim 1, wherein the reading light source device is arranged as follows. The holder includes a holding portion for holding the LED substrate, and a bent portion is formed on each of the upper and lower end portions of the holding portion, or one of the holders, and each bent portion is formed on the inner side of the casing. The light source device for reading according to claim 1 or 2 , wherein the holder is fixed in a state of being in surface contact with a surface. Reading light source device according to any one of claims 1 to 3, characterized in that the reflecting surface of the reflector is formed on the concave surface covering the emitting surface of the LED.

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