JP2003016383A - Optical information reader - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem that when illumination light which is intensely converged to illuminate over a long distance to read a bar code and a two-dimensional code at a distance in a dark place, the read visual field of a lens of an imaging means is larger at a long distance than a lighting area and the read visual field outside the lighting area is of no use. SOLUTION: A light projection means projects the illumination light on optical information at a long distance by a long-distance light projection means which forms the fixed lighting area including the photodetection axis of an imaging means by converging the illumination light and a distance measuring means measures the distance to the optical information; and a power adjusting means sets and adjusts the power according to distance information of the distance measuring means so that the lighting area nearly matches the visual field of the imaging means at the position of the optical information and the imaging means photodetects reflected light from the optical information and images the light on an image sensor.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical information reader for reading optical information such as bar codes and two-dimensional codes.

[0002]

2. Description of the Related Art A conventional optical information reading apparatus projects an illuminating light onto optical information such as a bar code or a two-dimensional code, and reflects light reflected from the optical information by an image sensor such as a lens. The image data of the optical information formed on the image is converted into an electric signal by the image sensor, and the electric signal is processed by the circuit board electrically connected to the image sensor before the optical signal is processed. Performs information decoding processing.

[0003]

In recent years, barcodes and 2
With the spread of dimension codes, there is an increasing demand for reading barcodes and two-dimensional codes that are far from the user in the dark, such as when reading barcodes and two-dimensional codes attached to luggage in warehouses. However, when illuminating light that is strongly condensed to illuminate a long distance is used, the reading field of view of the lens of the image forming means is larger than the illumination area at a long distance, and the reading field outside the illumination area is wasted.

[0004]

In order to solve the above-mentioned problems, an optical information reading apparatus according to claim 1 of the present invention comprises a light projecting means for projecting illumination light onto optical information, and the optical information reading means. Image forming means for receiving reflected light from information to form an image, an image sensor for converting image information of the optical information formed by the image forming means into an electric signal, and processing the electric signal. And a signal processing means for decoding the optical information, a distance measuring means for measuring a distance from the optical information, and a magnification adjusting means for changing a magnification of the image forming means. The means has a long-distance projection means for projecting the optical information at a long distance, and the long-distance projection means collects the illumination light to form a fixed illumination area including the light receiving axis of the image forming means. However, the magnification adjusting means is configured to measure the distance when the long-distance light projecting means is used. Field of view of the imaging means and the illumination area at the location of the optical information from the stage distance information is adjusted by setting the magnification to match approximately.

The optical information reader according to a second aspect of the present invention is the optical information reading apparatus according to the first aspect, wherein the magnification adjusting means of the distance measuring means forms an image on the image sensor with the magnification of the image forming means being a predetermined magnification. The distance from the optical information is measured from the image information indicating the illumination light of the distance projection means.

An optical information reading apparatus according to a third aspect of the present invention is the optical information reading apparatus according to the first aspect, further comprising illumination area information indicating means for indicating information about the illumination area of the long-distance light projecting means.

The optical information reader according to a fourth aspect of the present invention is the optical information reading apparatus according to the third aspect, wherein the distance adjusting means has the magnification adjusting means imaged on the image sensor with the magnification of the image forming means being a predetermined magnification. The distance from the optical information is measured from the image information indicating the area information indicating means.

According to a fifth aspect of the present invention, there is provided the optical information reading apparatus according to the first aspect, wherein the light projecting means is a long-distance light projecting means and a short-distance light field for projecting the short-distance optical information. It has a light projecting means and a switching means for switching between the long distance light projecting means and the short distance light projecting means.

According to a sixth aspect of the present invention, in the optical information reading apparatus according to the fifth aspect, the switching means switches the light projecting means by judging from the distance information of the distance measuring means.

According to a seventh aspect of the present invention, there is provided an optical information reading apparatus which projects an illumination light onto the optical information and a reflected light from the optical information to form an image. An image forming unit, and an image sensor for converting image information of the optical information formed by the image forming unit into an electric signal,
The light projecting means includes signal processing means for processing the electric signal to decode the optical information, and magnification adjusting means for changing the magnification of the image forming means. It has a long-distance light-projecting means for projecting information, and the long-distance light-projecting means collects illumination light to form a fixed illumination area including the light-receiving axis of the image forming means, and the magnification adjusting means is an image sensor. The magnification is set and adjusted so that the illumination area and the field of view of the image forming unit substantially match at the position of the optical information based on the image information indicating the illumination light of the long-distance light projecting unit imaged on.

An optical information reading apparatus according to claim 8 of the present invention is a projection means for projecting illumination light onto the optical information, and a reflected light from the optical information is received to form an image. An image forming unit, and an image sensor for converting image information of the optical information formed by the image forming unit into an electric signal,
The long-distance light emitting device includes signal processing means for performing signal processing on the electric signal to perform decoding processing of the optical information, wherein the light projecting means collects illumination light to project the optical information at a long distance. The image forming means includes a light projecting means and a short distance light projecting means for illuminating illumination light wider than the long distance light projecting means and projecting optical information at a short distance. It can be switched to one having a focal point and one having a focal point at a short distance at a wide angle of view, and when using the long-distance projection means, the image forming means has a focal point at a long distance at a narrow angle of view, When the short distance light projecting means is used, the image forming means has a wide field angle and a close focus at a short distance.

[0012]

According to the first optical information reading apparatus of the present invention, the light projecting means collects the illumination light and forms a fixed illumination area including the light receiving axis of the image forming means. Illumination light is projected onto the optical information at a long distance by the light projecting means, the distance measuring means measures the distance to the optical information, and the magnification adjusting means optically calculates the distance information from the distance measuring means. The magnification is set and adjusted so that the illumination area and the field of view of the image forming means substantially match at the information position, and the image forming means receives the reflected light from the optical information and forms an image on the image sensor. The sensor converts the image information of the formed optical information into an electric signal,
The signal processing means performs signal processing on the electric signal to decode optical information.

According to the second optical information reading apparatus of the present invention, the distance measuring means is the illumination light of the long-distance light projecting means imaged on the image sensor by the magnification adjusting means with the magnification of the image forming means being a predetermined magnification. The distance from the optical information is measured from the image information indicating.

According to the third optical information reader of the present invention, the illumination area information indicating means indicates information about the illumination area of the long-distance light projecting means.

According to the fourth optical information reading apparatus of the present invention, the distance measuring means is an image showing the illumination area information indicating means formed on the image sensor by the magnification adjusting means with the magnification of the image forming means being a predetermined magnification. The distance from the information to the optical information is measured.

According to the fifth optical information reading apparatus of the present invention, the light projecting means projects the long distance light projecting means for projecting the long distance optical information and the short distance optical information by the switching means. Switches the short-distance light emitting means for light emission.

According to the sixth optical information reader of the present invention, the switching means switches the light projecting means by judging from the distance information of the distance measuring means.

According to the seventh optical information reader of the present invention, the light projecting means is a long-distance light projecting means for converging the illumination light to form a fixed illumination area including the light receiving axis of the image forming means. , The illuminating light is projected onto the optical information at a long distance, the image forming means receives the reflected light and forms an image on the image sensor, and the image sensor forms the image of the illuminating light of the long distance projecting means. The image information of the image is converted into an electric signal, and the magnification adjusting means adjusts the magnification of the image forming means so that the image of the illumination light substantially coincides with the entire image, that is, the field of view of the image forming means. The reflected light from the optical information is received to form an image on the image sensor, the image sensor converts the image information of the formed optical information into an electric signal, and the signal processing means processes the electric signal. Decode optical information.

According to the eighth optical information reading apparatus of the present invention, the light projecting means includes the long-distance light projecting means and the short-distance light projecting means, and the light projecting means collects the illumination light to cover the long-distance light. When it is a long-distance projection means for projecting optical information, the imaging means has a narrow angle of view and has a focal point at a long distance, and the projection means irradiates illumination light wider than the long-distance projection means to provide a short distance. In the case of a short-distance light projecting means for projecting the optical information, the image forming means has a focal point at a short distance at a wide angle of view. The image forming means receives the reflected light from the optical information and forms an image on the image sensor, the image sensor converts the image information of the formed optical information into an electric signal, and the signal processing means converts the electric signal. Signal processing is performed to decode optical information.

An optical information reading device according to an embodiment of the present invention will be described below with reference to the drawings.

(Embodiment 1) FIG. 1 is a perspective view showing the appearance of an embodiment of the present invention. Optical information reader 1
Is a reading unit 4 for reading optical information 3 such as a bar code or a two-dimensional code on the front part of the outer case 2.
The rear part of the outer case 2 has a grip portion 5 for the operator to hold with his / her hand, the display screen 6 on the upper surface of the outer case 2 is a key input portion 7, the battery 8 is on the rear portion of the outer case 2, and the side surface is read. A start key 9 is arranged.

FIG. 2 is a schematic exploded perspective view illustrating the reading unit 4. The imaging lens 10 that receives the reflected light from the optical information 3 and forms an image is adjusted in position by the imaging optical system drive unit 11 so that the magnification and the focus are adjusted. The image sensor 12 converts the image information formed by the imaging lens 10 into an electric signal and electrically connects the circuit board 13
Transfer the signal to. The light emitting diode 14 is a light source for projecting illumination light over a long distance, and the light emitted from the light emitting diode 14 is controlled by the long distance light projecting lens 15 to form a certain illumination area and a relatively long distance. However, it is projected so that the illumination illuminance is maintained. The light emitting diode 16 is a light source for projecting illumination light in a short distance, and the light emitted from the light emitting diode 17 is diffused by the short distance light projecting lens 17 so that the illumination illuminance becomes uniform at a relatively short distance. To be done. The laser beam scanning unit 18 scans the laser beam by shaping the laser beam from the semiconductor laser 19 by the condenser lens 20 and reflecting the beam by the scanning mirror 22 which is fixed to the bimorph oscillator 21 and moves in amplitude. 23
To make the scanning range of the laser beam substantially the same as the illumination range in the horizontal direction by the long-distance projection from the light emitting diode 14. FIG. 3 is a front view showing an outline of a long-distance illumination light projection range (a), a short-distance illumination light projection range (a), and a laser beam scanning range (c) of the laser scanning unit 18. It is a figure.

FIG. 4 is a schematic diagram showing the electrical construction of the optical information reader. The image sensor 12 which converts the image information formed by the image forming lens 10 into an electric signal is driven by a signal from the reading CPU 24. The A / D conversion circuit 25 amplifies and noise-cuts the electric signal converted by the image sensor 10 and then digitizes it. The image memory 26 stores digitized image data.

The reading CPU 24 uses the digital image information stored in the image memory 26 based on a program.
Extract the position and angle of optical information as a black and white binary image,
Then, the decoding process of the optical information is performed. The data that is obtained by decoding the information encoded in the optical information is the main C
It is transferred to the PU 27 and used. Read CP
U24 controls the drive of the image forming optical system drive unit 11 via the image forming optical system drive control circuit 28, and controls the turning on and off of the light emitting diodes 14 and 16 via the light projecting control circuit 29. Through the beam scanning control circuit 30, the laser diode 19 of the laser beam scanning unit 18 is turned on and off, and the driving of the scanning mirror by the bimorph oscillator 21 is controlled.

In such a configuration, the optical information 3 such as a two-dimensional code is made to face the reading section 4 of the optical information reading device 1 and the reading start switch 9 is pushed. The main CPU 27 detects that the reading start switch 9 has been pressed, and causes the reading CPU 24 to start the reading process. The reading CPU 24 follows the program,
The imaging optical system drive unit 11 is driven via the imaging optical system drive control circuit 28 to adjust the position of the imaging lens 10 to fix the magnification and the focus position at initial values, and the laser beam scanning control circuit 30 is set. The laser beam is scanned by the laser beam scanning unit 18 via the above. The reflected light from the laser beam scanning the surface provided with the optical information 3 is imaged on the image sensor 12 by the imaging lens 10. The image information formed is converted by the image sensor 12 into an electric signal for each light amount received by each of the two-dimensionally arranged light receiving elements. The converted electric signal is converted into an A / D conversion circuit 2
It is digitized by 5 and stored in the image memory 26. Next, the reading CPU 24 turns off the laser beam via the laser beam scanning control circuit 30, similarly acquires digitized image information of the surface to which the optical information 3 is added, and the previously stored laser beam is scanned. The image due to the reflected light from the scanned laser beam is emphasized by making a difference from the digital image data during the operation. FIG. 5 shows the image data thus obtained. FIG. 6 is a side view for explaining the field of view (d) of the imaging lens 10 fixed to the initial value and the scanning plane position (e) of the laser beam from the laser beam scanning unit 18. As shown in FIG. 6, when the optical information 3 is at a short distance position (f), the image of the scanned laser beam is located below the image data area, and the optical information 3
Is located above the image data area at the long-distance position (G) than at the short-distance position (F). Thus, the position of the image with respect to the image data area, the optical information 3, and the optical information reading device 1
There is a one-to-one correspondence with the distances to and, and this is used as distance measuring means. The reading CPU 24 compares the light intensities of the laterally divided areas a, b, c, d, e, f, and g as shown in FIG. 5 to obtain the scanned laser beam in the image data area. The position of the image (H) is specified, and the distance between the optical information 3 and the optical information reading device 1 is calculated. Next, the reading CPU 24 determines whether the optical information 3 is a short distance or a long distance according to the program. When it is determined that the distance is long, the reading CPU 24 turns on the light emitting diode 14 for long-distance light projection via the light projection control circuit 29, and calculates the calculated optics via the imaging optical system drive control circuit 28. From the distance between the optical information 3 and the optical information reading device 1, at the position of the optical information 3, the field of view of the imaging lens 10 is formed by the long-distance projection lens 15 using the light-emitting diode 14 as a light source for long-distance illumination. The magnification is adjusted to be substantially the same as the area, and at the same time, the imaging optical system drive unit 11 is driven to adjust the focusing position, and the position of the imaging lens 10 is adjusted. FIG. 7 is a front view for explaining the field of view (K) before position adjustment of the imaging lens and the long-distance illumination area (C) formed by the long-distance projection lens 15 using the light emitting diode 14 as a light source. FIG. 8 is a front view illustrating the field of view (position) after the position adjustment of the imaging lens and the long-distance illumination region (X) formed by the long-distance projection lens 15 using the light emitting diode 14 as a light source. While the laser beam from the laser beam scanning unit 18 remains OFF, the reflected light from the optical information 3 irradiated with the long-distance illumination light formed by the long-distance light projecting lens 15 using the light emitting diode 14 as a light source is combined. An image is formed on the image sensor 12 by the image lens 10, the image information formed is converted into an electric signal by the image sensor 12, digitized by the A / D conversion circuit 25, and stored in the image memory 26. The reading CPU 24 converts the digital image information stored in the image memory 26 into a black and white binary image based on a program, extracts the position and angle of the optical information, and decodes the optical information. The light emitting diode 14, which is a light source for long-distance illumination, is turned on for a predetermined time and then turned off. The laser beam from the laser beam scanning unit 18 is turned off for a predetermined time and then turned on. The timing is controlled so that the time when the charge is accumulated by the photoelectric conversion of the light receiving element of the image sensor 12 is the time when the light emitting diode 14 is turned on and the laser beam is turned off. FIG. 9 shows the charge accumulation time of the light receiving element of the image sensor 12 and the light emitting diode 14
FIG. 7 is a diagram for explaining the timing of turning on / off and turning on / off the laser beam. When the decoding of the optical information is successful, the decoding result is transferred to the main CPU 24, and the reading process ends. If the decoding fails, the reflected light from the optical information 3 is imaged again to obtain the image data and the image data is decoded. If the decoding fails a predetermined number of times, the imaging lens 10 is returned to the initial position and the laser The process starts again from the process of calculating the distance between the optical information 3 and the optical information reading device 1 using the beam image.

When it is determined from the distance measurement result that the optical information 3 is a short distance, the reading CPU 24 turns on the light emitting diode 16 for short distance light emission via the light emission control circuit 29 to form an image forming optical system. The lens is fixed at the initial position and the laser beam from the laser beam scanning unit 18 is turned off.
As it is, the reflected light from the optical information 3 irradiated with the short-distance illumination light diffused by the short-distance light projecting lens 17 using the light emitting diode 16 as a light source is imaged on the image sensor 12 by the imaging lens 10. Then, the formed image information is converted into an electric signal by the image sensor 12, digitized by the A / D conversion circuit 25 and stored in the image memory 26, and is made into a black and white binary image based on the program, The position and angle of the optical information are extracted, and the optical information is decoded. As when it is determined to be a long distance, the light emitting diode 16 which is the light source of the short distance illumination is turned on for a predetermined time and then turned off. The laser beam from the laser beam scanning unit 18 is turned off for a predetermined time and then turned on. The timing is controlled so that the time when the charge is accumulated by the photoelectric conversion of the light receiving element of the image sensor 12 is the time when the light emitting diode 16 is turned on and the laser beam is turned off. Similarly, when the decoding fails, the reflected light from the optical information 3 is imaged again to obtain the image data and decoded, and when the decoding fails a predetermined number of times, the image of the laser beam is used. The process starts again from the process of calculating the distance between the optical information 3 and the optical information reading device 1. FIG. 10 is an explanatory diagram summarizing the flow of the above reading processing.

In this embodiment, the image of the scanned laser beam is used as the distance measuring means, but a distance measuring sensor using a PSD light receiving element may be used.

Further, as the distance measuring means, long distance illumination may be used as follows. According to the program, the reading CPU 24 drives the imaging optical system drive unit 11 via the imaging optical system drive control circuit 28 to adjust the position of the imaging lens 10 to fix the magnification and the focus position to the initial values, The light emitting diode 14 is turned on via the light emission control circuit 30,
Long-distance projection lens 15 using light emitting diode 14 as a light source
To form a long range lighting. The reflected light of the long-distance illumination on the surface on which the optical information 3 is attached is imaged on the image sensor 12 by the imaging lens 10, converted into an electric signal by the image sensor 12, and by the A / D conversion circuit 25. It is digitized and stored in the image memory 26. Next, the reading CPU 24 turns off the light emitting diode 14 via the light emission control circuit 30, acquires the digitized image information of the surface to which the optical information 3 is attached in the same manner, and illuminates the long-distance illumination previously stored. The image due to the reflected light of the scanned long-distance illumination is emphasized by making a difference with the digital image data during the operation. FIG. 11 shows the image data thus obtained. FIG. 12 shows the field of view (s) of the imaging lens 10 fixed to the initial value and the illumination area (s) of the long-distance illumination light.
It is a front view explaining. As shown in FIG. 12, when the optical information 3 is at a short-distance position (SO), long-distance illumination does not enter the visual field (S). When an image in which the long-distance illumination does not fit in the field of view (s) is acquired, it is determined that the distance between the optical information 3 and the optical information reading device 1 is a short distance. When the optical information 3 is at the long-distance position (ta), the long-distance illumination enters the field of view (s), and the image size (h) of the long-distance illumination occupying the entire image shown in FIG. Become. The distance between the optical information 3 and the optical information reading device 1 is calculated by detecting the size of the image of the long-distance illumination in the entire image.

Further, when the image of the illumination light is smaller than the entire image, that is, the field of view of the image forming means, directly from the image information of the image of the illumination light of the long-distance light emitting means before the calculation of the distance, the magnification of the image forming means. If the image cannot be discriminated to be larger than the entire image, that is, the field of view of the image forming means, the magnification of the image forming means is repeatedly decreased to make a large adjustment with the illumination light of the long-distance light projecting means while adjusting the position of the optical information. The illumination area and the field of view of the image forming means may be substantially matched with each other.

(Embodiment 2) FIG. 13 is a front view for explaining a schematic configuration of a reading unit according to Embodiment 2 of the present invention. In the imaging lens 31 that receives reflected light from optical information and forms an image, the operator slides the slide lever 32 to slide the front group lens 31a in the direction of (T) shown in the figure. And the angle of view becomes narrower and the focal point is distributed at a long distance,
The sliding lever 32 is disengaged from the optical switch 33, and the optical switch 3
When 3 is turned off, it is detected that the front lens group 31a has moved. The image sensor 34 is an imaging lens 31
The image information formed by is converted into an electric signal and the signal is transferred to the electrically connected circuit board 35. The electric signal is amplified, noise-cut, and digitized. The reading CPU converts the digital image information into a black-and-white binary image based on a program, extracts the position and angle of the optical information, and decodes the optical information. The light emitting diode 36 is a light source that projects illumination light at a long distance,
The light emitted from the light emitting diode 36 is projected by the long-distance light projecting lens 37 to form a constant illumination area by suppressing the spread of the light and maintain the illumination illuminance even at a relatively long distance. The light emitting diode 38 is a light source for projecting illumination light in a short distance, and the light emitted from the light emitting diode 38 is in a short distance light projecting lens 3.
The light is diffused by 9 and projected so that the illumination illuminance becomes uniform at a relatively short distance. When projecting light, the CPU lights the light emitting diode 36 when the optical switch 33 is OFF, and lights the light emitting diode 38 when the optical switch 33 is ON.

In such a configuration, the optical information 3 is made to face the reading section 1 and the reading is started. When the optical information 3 is a long distance, the operator slides the slide lever 32 to slide the front lens group 31a in the direction of (8) shown in the figure, and the imaging lens 31 has a view angle of view. The focus becomes narrower and the distance becomes longer. In addition, the sliding lever 32 is an optical switch 33.
The light switch 33 is turned off, the light emitting diode 36 is turned on, and a long-distance illumination in which the spread of light by the long-distance projection lens 37 is suppressed is formed. FIG. 14 is a front view for explaining the field of view (TE) and the long-distance illumination area (G) of the imaging lens 31 in which the angle of view is narrowed and the focal point is focused at a long distance. When the optical information 3 is at a short distance, the operator returns the sliding lever 32 to the original position, so that the image forming lens 31 has a wide angle of view, and the in-focus point is focused at a short distance. In addition, the sliding lever 32
Enters the optical switch 33, the optical switch 33 is turned on, the light emitting diode 38 is turned on, and the short distance illumination uniformly diffused by the short distance light projecting lens 39 is formed. FIG. 15 is a front view for explaining the field of view (na) and the long-distance illumination area (d) of the imaging lens 31 in which the angle of view is widened and the focal point is focused at a short distance. After the long distance and the short distance are selected by the sliding lever 32 in this way, the reflected light from the optical information 3 is focused on the image sensor 34 by the imaging lens 31, and the image sensor 34 converts the image information into an electric signal. Converted,
After being amplified and noise-cut and digitized, it is converted into a black and white binary image based on a program, and the position and angle of optical information are extracted and the optical information is decoded.

[0032]

As is apparent from the above embodiments, according to the first optical information reader of the present invention, the light projecting means is
The long-distance light-projecting means that collects the illumination light to form a fixed illumination area including the light-receiving axis of the image-forming means projects the illumination light onto optical information at a long distance, and the distance-measuring means includes The distance from the optical information is measured, and the magnification adjusting means sets and adjusts the magnification so that the illumination area and the visual field of the image forming means substantially match at the position of the optical information from the distance information of the distance measuring means. Thus, it is possible to illuminate with sufficient illumination light even at a long distance, and it is possible to prevent the reading field of view of the lens of the image forming means from largely deviating from the illumination area, and prevent the reading field from being wasted.

According to the second optical information reading apparatus of the present invention, the distance measuring means includes the illumination light of the long-distance light projecting means imaged on the image sensor by the magnification adjusting means with the magnification of the image forming means being a predetermined magnification. The distance from the optical information can be measured from the image information indicating, and it is not necessary to add a distance measuring sensor.

According to the third optical information reading apparatus of the present invention, the illumination area information indicating means indicates information about the illumination area of the long-distance light projecting means, and the operator can easily aim at the optical information 3.

According to the fourth optical information reading apparatus of the present invention, the distance measuring means is an image showing the illumination area information indicating means formed on the image sensor by the magnification adjusting means with the magnification of the image forming means being a predetermined magnification. It is possible to measure the distance from the optical information rather than the information, and it is not necessary to add a distance measuring sensor.

According to the fifth optical information reading apparatus of the present invention, the light projecting means projects the long distance light projecting means for projecting the long distance optical information and the short distance optical information by the switching means. The short-distance light emitting means for emitting light can be switched to increase the reading area.

According to the sixth optical information reading apparatus of the present invention, the switching means can switch the light projecting means by judging from the distance information of the distance measuring means.

According to the seventh optical information reader of the present invention, the light projecting means is a long-distance light projecting means for condensing the illumination light to form a fixed illumination area including the light receiving axis of the image forming means. , The illuminating light is projected onto the optical information at a long distance, the image forming means receives the reflected light and forms an image on the image sensor, and the image sensor forms the image of the illuminating light of the long distance projecting means. The image information of the image is converted into an electric signal, and the magnification adjusting means adjusts the magnification of the image forming means so that the image of the illumination light substantially coincides with the entire image, that is, the visual field of the image forming means. It can be illuminated with various illuminating light, and the reading field of the lens of the image forming means can be prevented from largely deviating from the illumination area, and the reading field can be prevented from being wasted.

According to the eighth optical information reading apparatus of the present invention, the light projecting means includes the long-distance light projecting means and the short-distance light projecting means, and the light projecting means collects the illumination light to project the long-distance light. When it is a long-distance projection means for projecting optical information, the image forming means has a narrow angle of view and has a focal point at a long distance, and the projection means radiates illumination light wider than the long-distance projection means. When it is a short-distance illumination means for projecting optical information on a distance, the image forming means has a wide angle of view and has a focal point at a short distance, so that it can be illuminated with sufficient illumination light even at a long distance. The reading field of the lens of the image forming means is prevented from being largely deviated from the illumination area, and the reading field is not wasted.

[Brief description of drawings]

FIG. 1 is a perspective view showing an appearance of an optical information reading device according to an embodiment of the present invention.

FIG. 2 is a schematic exploded perspective view illustrating a reading unit 4 of the optical information reading device according to the embodiment of the invention.

FIG. 3 is a front view for explaining an outline of a long-distance illumination light projection range, a short-distance illumination light projection range, and a laser beam scanning range of the optical information reader according to the embodiment of the present invention. Figure

FIG. 4 is a configuration diagram schematically showing an electrical configuration of an optical information reading device according to an embodiment of the present invention.

FIG. 5 is an explanatory diagram illustrating image data according to the embodiment of this invention.

FIG. 6 is a side view illustrating the field of view of the imaging lens and the scanning plane position of the laser beam according to the embodiment of the present invention.

FIG. 7 is a front view illustrating a field of view and a long-distance illumination area before position adjustment of the imaging lens according to the embodiment of the present invention.

FIG. 8 is a front view for explaining a field of view and a long-distance illumination area after position adjustment of the imaging lens according to the embodiment of the present invention.

FIG. 9 is an explanatory diagram for explaining the charge accumulation time of the light receiving element of the image sensor according to the embodiment of the present invention, and the timing of turning on / off the light emitting diode and turning on / off the laser beam.

FIG. 10 is an explanatory diagram summarizing the flow of reading processing according to the embodiment of this invention.

FIG. 11 is an explanatory diagram illustrating image data according to the embodiment of this invention.

FIG. 12 is a field of view of the imaging lens of the embodiment of the present invention,
Side view explaining the illumination area of the long-distance illumination light

FIG. 13 is a front view illustrating a schematic configuration of a reading unit according to a second embodiment of the present invention.

FIG. 14 is a front view for explaining a field of view and a long-distance illumination region of an imaging lens focused at a long distance at a high magnification according to the second embodiment of the present invention.

FIG. 15 is a front view for explaining a field of view and a long-distance illumination area of an imaging lens focused at a short distance at a low magnification according to the second embodiment of the present invention.

[Explanation of symbols]

10 Imaging lens 11 Imaging optical system drive unit 12 image sensor 14, 16 Light emitting diode 15 Long-distance projection lens 17 Near-field projection lens 18 Laser beam scanning unit

Claims (8)

[Claims] 1. A light projecting means for projecting illumination light onto optical information, an image forming means for receiving reflected light from the optical information to form an image, and the image formed by the image forming means. An image sensor that converts image information of optical information into an electric signal,
Signal processing means for processing the electrical signal to decode the optical information, distance measuring means for measuring the distance to the optical information, and magnification adjusting means for changing the magnification of the image forming means. The projection means has a long-distance projection means, and the long-distance projection means collects illumination light to form a fixed illumination area including a light receiving axis of the image forming means, and the magnification An optical information reading device, wherein the adjusting means adjusts the magnification from the distance information of the distance measuring means so that the illumination area and the visual field of the image forming means substantially match at the position of the optical information. 2. The distance measuring means measures the distance from the optical information from the image information indicating the illumination light of the long-distance light projecting means imaged on the image sensor by the magnification adjusting means using the magnification of the image forming means as a predetermined magnification. The optical information reader according to claim 1. 3. The optical information reading apparatus according to claim 1, further comprising an illumination area information indicating means for indicating information about an illumination area of the long-distance light projecting means. 4. The distance measuring means measures the distance from the optical information from the image information indicating the illumination area information indicating means imaged on the image sensor by the magnification adjusting means with the magnification of the image forming means as a predetermined magnification. 3. The optical information reading device described in 3. 5. The light projecting means includes a long-distance light projecting means, a short-distance light projecting means for projecting the short-distance optical information, and a means for switching between the long-distance light projecting means and the short-distance light projecting means. 4. The optical information reader according to claim 1, 2 or 3. 6. The optical information reader according to claim 5, wherein the switching means switches the light projecting means based on the distance information of the distance measuring means. 7. A light projecting means for projecting illumination light onto optical information, an image forming means for receiving reflected light from the optical information to form an image, and the image formed by the image forming means. An image sensor that converts image information of optical information into an electric signal,
The light projecting means includes signal processing means for processing the electric signal to decode the optical information, and magnification adjusting means for changing the magnification of the image forming means. It has a long-distance light-projecting means for projecting information, and the long-distance light-projecting means collects the illumination light to form a fixed illumination area including the light-receiving axis of the image forming means, and the magnification adjusting means is an image. From the image information indicating the illumination light of the long-distance light projecting means formed on the sensor, the magnification is set and adjusted so that the illumination area and the visual field of the image forming means substantially match at the position of the optical information. Optical information reader. 8. A light projecting means for projecting illumination light onto optical information, an image forming means for receiving reflected light from the optical information to form an image, and the image formed by the image forming means. An image sensor that converts image information of optical information into an electric signal,
The long-distance light emitting device includes signal processing means for performing signal processing on the electric signal to perform decoding processing of the optical information, wherein the light projecting means collects illumination light to project the optical information at a long distance. The image forming means includes a light projecting means and a short range light projecting means for projecting illumination light wider than the long range light projecting means to project optical information at a short range, and the image forming means focuses at a narrow angle of view and a long distance. Can be switched to one with a wide field angle and a focus point at a short distance at a wide angle of view, and when the long-distance light projecting means is used, the image forming means has a narrow field angle and has a focus point at a long distance. An optical information reading device in which when the distance projection means is used, the image forming means has a wide field angle and a close focus at a short distance.