JP2563746Y2 - Information reading device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an information reading apparatus such as a bar code reader for reading a bar code which is printed binary information. 2. Description of the Related Art An apparatus of this kind is for reading a bar code attached or printed on a product, and is used for manufacturing a factory.
It is applied to shipping lines or cash registers in supermarkets. In general, a bar code reader uses a laser light source that easily obtains a focused beam because a thin bar code is read by optical means. As this laser light source, due to market demands for miniaturization and long life of the device,
There are many transitions from gas lasers to semiconductor lasers.
In recent years, the reliability of semiconductor lasers has been improving year by year with the progress of semiconductor technology, and the price has been reduced. In addition, it has the feature of being compact and capable of direct modulation, and its use is rapidly expanding. Even with a semiconductor laser that has such prominent advantages, a barcode reader cannot view the light beam, so that it takes time and effort to install and adjust the position of the device, and damage to the human body (eye). There is a disadvantage that the danger is high. Currently, all semiconductor laser manufacturers
Lasers with visible light output are under development, and commercial products have near-infrared output (center wavelength of 780 nm or more). Conventionally, in order to solve the above-mentioned drawbacks, there has been proposed a method of visually displaying the position of a light beam of a semiconductor laser. Such a conventional method will be described with reference to FIG. FIG. 3 shows a scanner section of a bar code reader for displaying the position of the light beam of the semiconductor laser. However, the decoder section is omitted here. In FIG. 3, 1 is a semiconductor laser, 2 is a collimating lens that obtains parallel light from output light of the semiconductor laser 1, 3 is a rotating polygon mirror that deflects the parallel light, and 4 receives reflected light from the rotating polygon mirror 3. Barcode, 5, 7 are red (visible light) LED, 6,
Reference numerals 8 and 9 denote condensing lenses, respectively, and reference numeral 10 denotes a light receiver that receives reflected light from the bar code 4 via the condensing lens 9. [0004] The operation of the system in the bar code reader configured as described above will be described below. First, for basic bar code reading, a light beam emitted from a semiconductor laser 1 is converted into parallel light by a collimating lens 2, and the parallel light is incident on a rotary polygon mirror 3. When the rotary polygon mirror 3 rotates in the direction of arrow A in the figure, the reflected light from the rotary polygon mirror 3 scans the bar code 4 in the direction of arrow B.
In synchronization with this scanning, the reflected light from the barcode 4 is converted into an electric signal by the condenser lens 9 and the light receiver 10. The display of the scanning position is performed by spots C and D in the figure. For this purpose, the scanning end of the parallel light beam from the rotary polygon mirror 3 on the bar code 4 is irradiated by two sets of light-emitting elements, that is, red (visible light) LEDs 5 and 7 and condenser lenses 6 and 8 for illustration. Spots C and D are formed. [0005] However, in the above-described configuration, it is necessary to adjust the alignment of three light sources having different positions and spaces, that is, the alignment of the semiconductor laser 1 and the light beams of the red LEDs 5 and 7. If a great deal of time is required, and if the bar code 4 moves up and down in the depth direction, the positional relationship between the three light beams is disturbed. Therefore, it is necessary to perform adjustment again each time the installation conditions change. In addition, in order to display both ends of the scanning light beam, it is necessary to estimate the posture relationship between the scanning beam and the bar code which cannot be seen by the amount of eyes. Therefore, since it cannot be determined whether the scanning light beam is scanning the barcode surface reliably, there is a practically disadvantageous problem that it takes a lot of time to adjust the alignment between the device and the barcode. I was Accordingly, an object of the present invention is to eliminate the above-mentioned drawbacks of the conventional device and to display information on the scanning area of the light beam of the semiconductor laser which can be easily and reliably displayed by the minimum additional means. A reading device is provided. In order to achieve the above object, the present invention provides a first light source comprising a semiconductor laser and the first light source.
Means for converting a light beam emitted from a light source to a parallel light beam, a second light source for emitting visible light, means for converting a light beam emitted from the second light source to a parallel light beam, and the first light source and the second light source. A scanning unit that scans a scanning object by deflecting each light beam by a rotating polygon mirror, and a unit that receives and reads reflected light obtained by the scanning unit. The two light sources are located symmetrically with respect to a virtual plane including an intermediate point of the scanning area on the object scanned by the scanning means and the rotation axis of the rotary polygon mirror, and each light beam from the first light source and the second light source Are arranged so as to be incident on the reflection surface of the rotary polygon mirror at the same angle with respect to the virtual plane. According to the present invention, a laser light beam emitted from a first light source, an intermediate point of a scanning area on an object to be scanned by a scanning means, and a rotation axis of a rotary polygon mirror are included for the first light source. The visible light beam from the second light source arranged at a symmetrical position with respect to the virtual plane enters the reflecting surface of the rotating polygonal mirror at the same angle with respect to the virtual plane. Since the visible light beam deflected overlaps the scanning position on the scanning object by the laser light beam with a time difference, the scanning position on the scanning object by the invisible laser light beam is pseudo-displayed by the visible light beam. An embodiment of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a configuration diagram of a barcode reader showing one embodiment of the present invention. In FIG. 1, reference numeral 1 denotes a semiconductor laser again, reference numeral 2 denotes a collimating lens, reference numeral 3 denotes a rotary polygon mirror, reference numeral 4 denotes a bar code, reference numeral 9 denotes a condenser lens, and reference numeral 10 denotes a light receiver. This is the same as the conventional device shown. Furthermore, 11 is a red (visible light) LED, 12 is a collimating lens, and a red LED
The light from 11 is made parallel by the collimating lens 12,
The parallel light is made incident on the rotating polygon mirror 3, and is made incident on the bar code 4 while being superimposed on the light from the collimating lens 2. The operation of the bar code reader thus constructed according to the present embodiment will be described below with reference to FIG. The description of the operation of the barcode is the same as the operations of 1 to 4 and 9 and 10 of each part in FIG. 3, and thus the description thereof is omitted here. Here, as shown in FIG. 2, the semiconductor laser 1 and the red LED 11 are positioned with respect to an imaginary plane O including an intermediate point C of a scanning area E on the object scanned by the scanning means and a rotation axis a of the rotary polygon mirror 3. The light beams are arranged at opposing positions P and Q, and the respective light beams are collimated by the collimating lenses 2 and 12, and are identical to the virtual plane O at points R and S on the same reflecting surface of the rotary polygon mirror 3. At an angle θ1. Where R
And point S are located on the virtual plane O from the rotation axis of the rotary polygon mirror 3.
, The angle θ2 is set to １ ／ (11.25 ° in the case of an eight-sided rotating polygonal mirror) of the division angle based on the number of faces of the rotating polygonal mirror 3. On the other hand, the scanning width φ of the light beam formed by the number of divisions of the rotating polygon mirror 3 rotating about the rotation center point is defined by the following equation (1). Φ = 2 × 360 / n (1) n is the number of faces of the rotating polygon mirror 3. Therefore, the two parallel beams emitted from the points P and Q in the drawing are symmetrically and equiangularly incident on the virtual plane O, so that they pass through the same position on the scanning area. The time difference φ3 required to scan 2θ1 minutes is φ
The scan widths φ1 and φ2 are equal to 3. Here, φ1
Is the scan width formed by the reflection of the rotating polygon mirror from which the parallel beam from point P rotates, and φ2 is the scanning width formed by the reflection of the rotating polygon mirror from which the parallel beam rotates from point Q. At this time, if the R and S points on the reflecting surface are set so that θ1 is substantially equal to 2θ2, the scanning width φ
The center lines PO and QO of 1, φ2 have the highest parallelism with the virtual plane O. As a result, on the surface of the bar code 4, the two light beams have the time difference φ3, but overlap most. Needless to say, there is no light beam overlap at portions equivalent to the line segment RS at both ends outside the points R and S of the rotary polygon mirror 3, but this is practical if the scanning area E is made larger than the line segment RS. Does not matter. As described above, in the present invention, the light beam from the invisible semiconductor laser 1 and the visible light beam from the red LED 11 are simulated by the rotating polygon mirror 3 so as to overlap the bar code 4. Since the scanning light beam can be visually observed, the alignment between the device and the bar code can be adjusted in a short time. As described above, in the present invention, the first light source comprising the semiconductor laser, the means for converting the light beam emitted from the first light source into a parallel light beam, and the second light source for emitting visible light are provided. A light source and means for converting a light beam emitted from the second light source into a parallel light beam;
A scanning unit for scanning a scanning object by deflecting a light beam from a light source by a rotary polygon mirror, and a unit for receiving and reading reflected light obtained by the scanning unit; The second light source is located at a position symmetrical with respect to a virtual plane including an intermediate point of a scanning area on the object scanned by the scanning means and a rotation axis of the rotary polygon mirror, and each light from the first light source and the second light source. The visible light beam from the second light source is reliably located at the scanning position of the laser light beam from the first light source by arranging the beam so as to be incident on the reflecting surface of the rotary polygon mirror at the same angle with respect to the virtual plane. And the visible position of the laser light beam from the first light source can be visually recognized by the visible light beam from the second light source, and there is no need to provide an additional optical system to the conventional device. Formation is simple, also the scanning position of the laser beam since it is visible by the visible light beam can be performed in a short time alignment adjustment unit (barcode reader) and barcode. 2 more
Since the two scanning lines have the same optical path, even if the bar code moves up and down in the depth direction, the combining position does not change, and if the combining adjustment is completed at the time of shipment, it is not necessary to adjust the position of the light beam in the field. Thus, there is no burden on the user, and the usability can be significantly improved.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a configuration diagram showing a scanner section of a semiconductor laser barcode reader according to an embodiment of the present invention. FIG. 2 is a diagram illustrating an operation of scanning line display of the semiconductor laser barcode reader in FIG. FIG. 3 is a block diagram showing a scanner unit in an example of a conventional semiconductor laser barcode reader. [Description of References] 1 semiconductor laser 2 collimating lens 3 rotating polygon mirror 4 barcode 5 red LED 6 condensing lens 7 red LED 8 Condensing lens 9 Condensing lens 10 Receiver 11 Red LED 12 Collimating lens

Claims (1)

(57) [Rules for requesting registration of utility model] A first light source comprising a semiconductor laser, means for converting a light beam emitted from the first light source into a parallel light beam, a second light source emitting visible light, and means for converting a light beam emitted from the second light source into a parallel light beam And the first light source and the second light source.
An information reading device comprising: a scanning unit that scans a scanning object by deflecting each light beam from a light source by a rotating polygon mirror; and a unit that receives and reads reflected light obtained by the scanning unit. And the second light source is a symmetric position with respect to an imaginary plane including an intermediate point of a scanning area on the object to be scanned by the scanning means and a rotation axis of the rotary polygon mirror, and each of the first light source and the second light source An information reading device, wherein a light beam is arranged so as to be incident on the reflection surface of the rotary polygon mirror at the same angle with respect to the virtual plane.