JPH0685189B2 - Information reader - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an information reading device such as a bar code reader for reading a bar code, and more particularly to a structure of a reading unit (hereinafter referred to as a scanner).

[Conventional technology]

This type of information reading device reads a bar code attached or printed on a product, and is applied to production at a factory, a shipping line or a cash register at a store. In general, a bar code reader uses a laser light source that can easily obtain a focused light beam because a plurality of thin bars are read by optical means. As a laser light source, there is a tendency to shift from a gas laser to a semiconductor laser due to demands for downsizing and long life of the entire device. However, the semiconductor laser also has a problem that it takes time and effort to install and adjust the posture of the device because the light beam cannot be visually observed when it is used for a bar code reader. A method of visually displaying the position of the light beam was adopted. FIG. 3 is a plan view of the scanner of the bar code reader according to this method, and FIG. 4 is a side view of FIG. In the figure, 1 is an LD unit (Laser Device Unit) consisting of a semiconductor laser and a collimating lens that collimates the light beam from the semiconductor laser, 2 is a rotary polygon mirror of a motor drive that deflects this parallel light, and 3 and 4 are visible LED unit consisting of light LED (Light Emitting Diode) and condenser lens, 5 PD unit (Passive Device Unit) consisting of condenser lens and light receiver, 6 exit window through which light beam passes, 7 and 8 LED units The support columns 3 and 4 are respectively supported, 9 is a scanner base for holding each device and parts except the above-mentioned emission window 6, and 10 is a cover having the emission window 6 on the front surface.

Next, the system operation of the scanner of the bar code reader thus constructed will be described.

First, for basic barcode reading, LD unit 1
When the parallel light beam A emitted from is incident on the rotary polygon mirror 2, the reflected light passes through the exit window 6 and is emitted to the outside as the rotary polygon mirror 2 rotates, and scans between B and C. The scan area is represented by F. The reflected light G from the bar code (not shown) in this area F enters the PD unit 5 in synchronization with the rotation of the rotary polygon mirror 2 and is converted into an electric signal here. The LED units 3 and 4 are arranged at positions where the emitted visible light beams D and E surround the scanning region F, and therefore, both ends of scanning are displayed on a bar code (not shown).

[Problems to be Solved by the Invention]

However, in the configuration as described above, three light sources with different positions and spaces, namely the LD unit 1 and the LED unit
It takes a lot of time to adjust the position of each light beam from 3, 4 when the device is shipped, and the arrangement of each unit including the PD unit 5 is three-dimensional and complicated. For example, columns 7, 8 are provided. However, there is a problem in that the size of the device is increased and the product cost is increased in order to secure the space required for each unit.

Therefore, in view of the above-mentioned circumstances, an object of the present invention is to provide a small-sized and inexpensive information reading device by simply and reliably displaying the scanning area of the light beam from the LD unit by using the minimum optical means. The purpose is to do.

[Means for Solving the Problems]

In order to achieve the above-mentioned object, in the present invention, a first light source unit that emits parallel laser light beams, a second light source unit that emits parallel visible light, and the first light source unit and the second light source unit are used. Information reading in which scanning means for scanning a scanning object by polarizing both light beams emitted by a rotating polygon mirror and reading means for receiving and reading the reflected light obtained from the scanning object are arranged on the same holding table. In the apparatus, the second light source unit that emits visible light has a structure in which visible light from the light source is reflected and refracted by a reflecting mirror and then focused and emitted through a condenser lens. The first light source unit is at a symmetrical position with respect to the scanning axis of the rotary polygon mirror of the scanning means, and the respective light beams emitted from the first light source unit and the second light source unit are reflected by the rotary polygon mirror by the same reflection. The scanning polygonal mirror is arranged so that it is incident from the same predetermined angle direction with respect to the central axis of scanning, and the reading means is arranged at an intermediate position between the first light source unit and the second light source unit. Is characterized by.

[Work]

The LD unit, which is the first light source unit, and the LED unit, which is the second light source unit, are arranged on the same plane of the holder with the PD unit as the reading means interposed therebetween, and the light beams emitted from both units are placed on the same holder. Since the light beams are concentrated and incident on the same reflecting surface of the rotating polygon mirror which is the scanning means arranged, the alignment of both light beams is extremely easy and the adjustment time is short. Further, since the LED unit requires a long-focus condenser lens, the LE unit has a long dimension in the optical axis direction, but in the present invention, the optical axis of the LED unit is refracted by refracting the light beam using a reflecting mirror. Since the length in the lengthwise direction has been shortened to about half that of the conventional type, the lengthwise dimension of the device also becomes shorter. That is, the entire device has a simple structure and is miniaturized.

〔Example〕

FIG. 1 is a plan view of a scanner of an information reading apparatus according to an embodiment of the present invention, and FIG. 2 is a side view of the scanner of the same as above.
Parts having the same functions as those of the conventional scanner shown in FIGS. 4 and 5 are designated by the same reference numerals. The rotary polygonal mirror 2 is attached to the horizontal plane 9a of the scanner base 9 in such a posture that the anti-slope 2a is vertical, and on the inclined plane 9b that is lower than the horizontal plane 9a, symmetrical with the central axis 11 perpendicular to the reflection plane 2a. The LD unit 1 is installed so that the light beam A can be incident at the same position and at the same angle with respect to the central axis 11 for scanning. The LED unit 13 includes a light source (LED) 13a and a reflecting mirror 13b.
The light beam from the light source (LED) 13a is reflected by the reflecting mirror 13b, and the reflected light is emitted from the collecting lens 13c. LED unit
It is generally the LED that has 13 long optical paths.
Since the area that emits light is much wider than that of a semiconductor laser, it requires a long-focus condenser lens 13c to make parallel light with a high brightness that is thin on the scanning surface. Therefore, a reflecting mirror 13b is interposed in the middle of the optical axis to refract the optical axis so that the length of the LED unit 13 in the optical axis direction is short and the optical axis length of the LED can be long. This LED unit 13 is also installed on the inclined surface 9b to which the LD unit 1 is attached, and its position is the reflection surface 2a.
The light beam H emitted from the condenser lens 13c of the LED unit 13 is incident on the reflecting surface 2a at a predetermined angle θ with respect to the LD unit 1 and the reflection side with respect to the central axis 11 which is perpendicular to. PD
The unit 5 is attached to the scanner base 9 between the LD unit 1 and the LED unit 13 at a position where the reflected light G from a bar code (not shown) can be vertically received, and the exit window 6 is covered.
It is installed on the front side of 10.

The operation of the bar code reader configured as described above will be described. The parallel light beam A emitted from the LD unit 1 and the parallel light beam H emitted from the LED unit 13 with respect to the central axis 11 of scanning. The light is incident on the same reflecting surface 2a of the rotary polygon mirror 2 from opposite directions while maintaining the same incident angle θ. The rotation of the rotary polygon mirror 2 causes the two light beams A,
The reflected light of H is emitted to the outside from the exit window 6 and scans between B and C to form regions F and F ′, which overlap on the scanned object. In this embodiment, the LD unit 1 and the LED unit 13 are installed at opposite positions, and the PD unit 5 is arranged at the center between them, so that the LD unit 1, the LED unit 13 and the PD unit 5 are sized according to the dimensions. , If the incident angle θ is selected, the third
A more efficient arrangement can be expected than the arrangement of the bar code reader / scanner shown in FIGS. Moreover, as described above, the LED unit 13 is made particularly compact by shortening the optical axis direction, and all the units constituting the scanner can be directly installed on the scanner base 9 without using columns or the like, so that the LED unit 13 becomes compact. As described above, the light beam A from the LD unit 1 which is not visible in the present invention and the light beam B from the LED unit 13 which is visible can be combined by the rotating polygon mirror 2 so as to overlap with each other on the scanning object, and the device is shipped. The time adjustment is simplified, and the LD unit 1 and the LED unit 13 are arranged at positions opposite to each other, and the PD unit 5 is arranged at the center of the intermediate portion thereof, so that a small and inexpensive device can be constructed.

〔The invention's effect〕

In this invention, the PD unit is sandwiched in the same scanner stand, and the LD unit that emits the invisible light beam and the LED unit that emits the invisible light beam are arranged on the rotating polygon mirror on both sides of the central axis perpendicular to the reflecting surface. Then, the respective light beams are made incident on the same reflecting surface of the rotary polygon mirror, and the scanning lines on the bar code are combined so that they overlap with each other with a time difference. Rotating multi-face required for bar code readers without the need for a special photosynthesizer such as a half mirror to display the light beam from the LED unit on the bar code because the column that holds the required unit is unnecessary. The scanning position of the laser light beam that scans the bar code is displayed by visible light without increasing the number of parts by also using a mirror. In addition, the LED unit is miniaturized, which has a practical advantage that the entire device can be miniaturized, the production cost can be reduced, and the accuracy can be improved.

[Brief description of drawings]

FIG. 1 is a plan view of a scanner of an information reading apparatus according to an embodiment of the present invention, FIG. 2 is a side view of FIG. 1, FIG. 3 is a plan view of a scanner of a conventional information reading apparatus, and FIG. It is a side view of FIG. 1: LD unit (first light source unit), 2: rotating polygon mirror (scanning means), 2a: reflecting surface, 5: PD unit (reading means),
9: Scanner stand (holding stand), 13: LED unit (second light source unit), 13a: light source, 13b: reflecting mirror, 13c: condenser lens, A,
H: light beam, θ: predetermined angle (incident angle).

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP 61-208176 (JP, A) JP 61-251980 (JP, A) JP 62-223718 (JP, A) JP 62- 180485 (JP, A)

Claims (1)

[Claims] 1. A first light source unit that emits parallel laser light beams, a second light source unit that emits parallel visible light, and both light beams emitted from the first light source unit and the second light source unit. Visible light is emitted in an information reading device in which scanning means for scanning a scanning object by polarization by a rotating polygon mirror and reading means for receiving and reading reflected light obtained from the scanning object are arranged on the same holding base. The second light source unit has a structure in which visible light from the light source is reflected and refracted by a reflecting mirror and then focused and emitted through a condenser lens. The second light source unit and the first light source unit are
The light beams emitted from the first light source unit and the second light source unit are located symmetrically with respect to the scanning axis of the rotary polygon mirror of the scanning means, and the respective light beams emitted from the first light source unit and the second light source unit are on the same reflecting surface of the rotary polygon mirror. The information reading device is arranged so as to be incident from the same predetermined angle direction with respect to the central axis of scanning, and the reading means is arranged at an intermediate position between the first light source unit and the second light source unit. .