JP2002092542A - Optical information reader - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the sureness in the read of a specified code located in a part of a reading visual field in a device having a two-dimensional reading visual field. SOLUTION: A code scanner comprises a reading mechanism consisting of an area sensor or lighting LED having a two-dimensional reading visual field F, and a marker LED located at both ends of the vertical middle part of the reading visual field F to emit a marker light M. The code scanner is constituted switchably to an entire reading mode for reading codes B and L in the whole reading visual field F of the area sensor and a partial area reading mode for reading the codes B and L located only in the horizontally long area of the vertical middle part of the reading visual field F. The marker light M is emitted only in the partial area reading mode. In the partial area reading mode, it is judged whether the code recording position to be read is precisely conformed to the irradiating position of the marker light M or not, and when it is not precisely conformed, decoding is not performed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reading mechanism including an area sensor and having a two-dimensional reading field of view, which is brought close to a reading object on which a code such as a bar code or a two-dimensional code is recorded. The present invention relates to an optical information reading device that reads a code in a state.

[0002]

For example, a bar code or a "QR code" is used in order to manage product sales and inventory.
A system using a two-dimensional code such as is provided, and as an optical information reading device for optically reading such a code, it is configured to have an area sensor, and the user holds the system by hand. There is a handy type two-dimensional code scanner (handy terminal) to operate. In this apparatus, a user reads a barcode or the like by bringing a reading unit at the tip of the reader close to a barcode or the like recorded on a reading target such as a slip and operating a trigger switch in that state. It has become.

At this time, since the two-dimensional code scanner has a sufficiently large two-dimensional field of view in the vertical direction, for example, a plurality of bar codes can be read from a reading object on which bar codes are printed in multiple stages. It is possible to read all at once. Some codes can also read characters / symbols for OCR reading. In this case as well, characters / symbols recorded in a plurality of rows can be read at once.

[0004] However, in the above-mentioned conventional apparatus, a part (specific) of a code to be read is printed from a plurality of read targets.
When it is desired to read only the code, the code is read with a blank sheet of paper or the like so that the other code does not enter the reading field of view. There was a very troublesome problem and it was not practical.

Therefore, a mode is provided in which only the center of the reading field is read (only the center of the area sensor is decoded), and the reading unit is positioned so that the code to be read comes in the center of the reading field. Then, it is conceivable to perform reading. However, in this case, since the user only has to guess the position of the center of the field of view and the code to be read, the position of the code must be roughly estimated.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to have a two-dimensional reading field, and to read a specific code located in a part of the reading field. An object of the present invention is to provide an optical information reading device capable of improving reliability.

[0007]

In order to achieve the above object, an optical information reading apparatus according to the present invention provides a marker light for reading a specific code located in a part of a two-dimensional reading field. The irradiating means irradiates the reading object with the marker light, and the partial reading means reads only the code of the portion of the reading field of the reading mechanism irradiated with the marker light ( The invention of claim 1).

According to this, when reading the code by bringing the apparatus close to the object to be read, the user is configured to irradiate the marker light to a specific code part to be read out of the object to be read. By performing the alignment, only the code can be read by the partial reading unit. Therefore, it is possible to improve the certainty in reading a specific code located in a part of the reading field of view.

In this case, there is provided mode switching means for switching between an entire reading mode for reading a code in the entire reading field of view and a partial area reading mode for reading only a code in a partial area of the reading field by the partial reading means. The marker light irradiation means can be operated only in the area reading mode (the invention of claim 2).
The marker light can be emitted only when necessary.

[0010] In addition, since the code read by the partial reading means is often elongated horizontally, such as a bar code or OCR reading character / symbol, a marker light consisting of spot light is read by a reading mechanism. By irradiating at least two positions on both ends of the horizontally long partial reading area in the field of view, alignment can be easily performed, and further, for example, the optical axis of the marker light and the area sensor If the marker light irradiation position is fixed with respect to the reading field by making the reading optical axis parallel or the like, the processing at the time of reading the code is simplified (the invention of claim 3).

However, depending on the arrangement of the area sensor and the marker light irradiating means, an angle occurs between their optical axes. For example, a change in the distance between the object to be read and the apparatus (marker light irradiating means) causes the reading mechanism to change. The irradiation position of the marker light with respect to the reading field of view will fluctuate. Therefore, a marker position specifying means is provided for detecting where the marker light is located in the reading field of the reading mechanism based on taking in an image by the reading mechanism in a state where the reading object is irradiated with the marker light. With this configuration (invention of claim 4), it is possible to reliably read only the code in the portion of the reading field of the reading mechanism irradiated with the marker light while improving the degree of freedom of the arrangement of the marker light irradiating means. Will be able to

Furthermore, if a determination means for determining whether the code recording position to be read and the marker light irradiation position correspond to each other is provided (the invention of claim 5),
Decoding can be performed only when the code is correctly positioned at the portion irradiated with the marker light, and reading errors and the like can be prevented beforehand. At this time, it is desirable to notify the user of the determination result of the determination means. If the configuration is such that the notification is performed by changing the irradiation form of the marker light (the invention of claim 6), it can be understood with a simple configuration. It can be easily notified.

When a code is read by a reading mechanism (area sensor), a photometric area is provided in a part of the reading field of view in order to make the difference between the black and white amplitudes in the code binarization process constant. Exposure control is performed based on the photometry result to adjust the amount of illumination at the time of code reading and the gain of the amplifier. As a result, stable decoding can be performed while eliminating the influence of disturbance light or the like. At this time, when only some codes in the reading field of view are read, the codes actually exist. If the part is not a photometric area, there is a risk that appropriate exposure control will not be performed.

Therefore, the exposure control means is configured to change the photometric area according to the type of the code (the invention of claim 7), or is configured to change the photometric area according to the irradiation position of the marker light. In this case (the invention of claim 8), it is possible to perform appropriate exposure control on the reading position where the code to be actually read exists, and it is possible to improve the reading performance.

Further, it is also possible to arrange so that a plurality of positions can be irradiated with marker light composed of spot light and that the position of the marker light to be irradiated is changed according to the type of code. According to this, for example, in the case of a horizontally long code such as a bar code or an OCR reading character / symbol, alignment is performed so that marker light is emitted to both ends of the horizontally long code, such as a two-dimensional code. In the case of a rectangular code, the marker light can be selectively used according to the type of the code, such as aligning the central portion so that the marker light is irradiated, and the alignment becomes easier. As a result, the readability of the code can be further increased.

Alternatively, the marker light composed of a plurality of spot lights may be irradiated in such a manner that the color of the marker light is made different according to the irradiation position (the tenth aspect of the present invention). For example, the user can distinguish the relationship between the irradiation positions of a plurality of marker lights by color, which facilitates the alignment, for example, an alignment error such as a part of the code being out of the reading field of view. Is excellent in the effect of preventing

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Several embodiments of the present invention will be described below with reference to the drawings.
The optical information reading apparatus in the embodiment described below includes a plurality of types of decoding software. By switching the software to be used, a two-dimensional bar code of various standards, a QR code, etc. Code, OCR
Various codes such as characters and symbols for reading can be read.

(1) First Embodiment First, a first embodiment (corresponding to claims 1, 2, 3, and 5) of the present invention will be described with reference to FIGS. FIG. 7 schematically shows the configuration of the code scanner 1 which is an optical information reading apparatus according to the present embodiment. The code scanner 1 is referred to as a handy terminal which is operated by a user while holding it by hand. The code scanner 1 not only reads codes, but also processes and stores the read code data, and further stores data with a management computer or the like. It also has a communication function and the like.

The code scanner 1 has a case 2
It includes a reading mechanism 3 for reading a code, a control device 4 (see FIG. 6), and the like. The control device 4
Are configured mainly with a microcomputer, and perform decoding processing of signals from the reading mechanism 3 (area sensor), control of the entire system, and the like. The case 2 has a grip portion on the base end side (right side in the figure), and is bent so that the front end side is slightly wider and slightly downwardly inclined forward, and the front end portion is a reading section 2a.

A key input unit 5 including a plurality of key switches 5a is provided on an upper surface of the case 2 so that a user can select and set a reading program and specify a code type. Has become. In addition, a trigger switch 6 for reading (shown only in FIG. 6) is also provided on the outer surface of the case 2. Further, a display unit 7 composed of, for example, an LCD is provided on the upper surface of the case 2. The key switch 5a, the display unit 7, and the like are mounted on a printed circuit board 8 disposed in the case 2, and although not shown, the control device 4 and the like are also mounted on the printed circuit board 8. ing. Although not shown, a secondary battery serving as a power supply is incorporated in the case 2.

On the other hand, the reading mechanism 3 includes an area sensor 9 composed of a CCD image sensor, an imaging lens 10 located in front of the area sensor 9, a plurality of illumination LEDs 11 serving as an illumination light source when reading a code, and It comprises an illumination lens 12 and the like located at the front. At this time, as shown in FIG.
It has a two-dimensional reading field F of 0 pixels and 400 pixels vertically. In addition, as shown in FIG. 8, the imaging lens 10 is disposed at the center of the reading unit 2a, and the plurality of illumination lenses 12 are disposed therearound.

Thus, the reading unit 2a reads the code (the bar code B shown in FIG. 1 (a) or the like or the character / symbol L for OCR reading shown in FIG. 1 (b) or the like). By performing a reading operation, that is, turning on the trigger switch 6 in a state where the object (a slip, a label, a catalog, or the like) is brought close to the object (a reference distance is, for example, 80 mm), the lighting L
In a state where the object to be read is illuminated by the ED 11, an image is taken by the area sensor 9 and, consequently, the code is read.

The reading mechanism 3 is provided with two marker LEDs 13 and a light projecting lens 14 as marker light irradiation means. The marker LED 13 and the light projecting lens 14 are located on the left and right portions of the area sensor 9 (imaging lens 10), and their optical axes P are parallel to the optical axis of the area sensor 9 (coincident when viewed from the horizontal direction). Do)
Are arranged at both ends of the middle portion in the vertical direction in the reading visual field F, and each of them is irradiated with marker light M composed of spot light. The irradiation positions of these marker lights M are located at both ends of a partial reading area described later. In this case, regardless of the distance between the reading unit 2a and the object to be read, irradiation is always performed at a fixed position with respect to the reading field of view F.

FIG. 6 schematically shows an electrical configuration of the code scanner 1 with the control device 4 as a center.
The control device 4 receives an operation signal of the key input unit 5 and the trigger switch 6 and controls the display unit 7. The control device 4 controls the illumination LED 11 and the marker LED 13.

The control unit 4 includes the area sensor 9
The imaging data of the code read by is read and decoded. At this time, although not shown, an amplifier for amplifying the imaging signal of the area sensor 9,
A binarization circuit for converting the data into binary data is provided. Further, the image memory 15 is connected to the control device 4 and the area sensor 9. Further, the control device 4 includes:
For example, a sound generation unit 16 that generates a buzzer sound when a code is read is connected, and a data communication unit 17 that performs data communication of decoded data or the like with an external device (such as a management computer) by infrared light is connected. .

The code scanner 1 has an entire reading mode for reading the code of the entire reading field F of the area sensor 9 and a code for a partial area of the reading field F (the irradiation area of the marker light M at both ends is determined). Switching to a partial area reading mode for reading only a connecting straight line (a code located on the marker line ef) is possible. In this case, since the irradiation position of the marker light M is fixed with respect to the reading visual field F, in the partial area reading mode, a code located in a horizontally long area in the vertical middle part of the reading visual field F is read. Will be.

These modes are switched by the software configuration (on a program) of the control device 4, and the control device 4 functions as a mode switching means and also functions as a part of the partial reading means. It has become. At this time, the marker LED 13 is
It is operated (lit) only in the partial area reading mode. In the present embodiment, for example, when the power of the code scanner 1 is turned on, the code scanner 1 is always lit except when the lighting LED 11 is turned on. Has become.

As will be described later in the description of the operation,
The control device 4 determines whether the code recording position to be read and the irradiation position of the marker light M correctly correspond to each other in the partial area reading mode,
It is determined whether or not the code is correctly positioned on a straight line (marker line ef) connecting the irradiated portions of the marker light M at both ends. If the code is not correctly positioned, decoding is not performed. Therefore, the control device 4 also functions as a determination unit.

Next, the operation of the above configuration will be described with reference to FIGS. Here, a case of reading a bar code B and characters / symbols L for OCR reading as codes will be described as an example. Now, as shown in FIG. 1, when a bar code B and characters / symbols L for OCR reading are printed in multiple stages on the reading object, the reading field F of the code scanner 1 is read.
Inside, a plurality of barcodes B (see FIG. 1A) and OC
The characters / symbols L for R reading (see FIG. 1B) are included. When it is desired to read only a part (specific) code from the reading target, the code scanner 1 is set to the partial area reading mode.

As described above, in this partial area reading mode, the marker LED 13 is turned on to emit the marker light M, and at the same time, the marker light M in the read field F of the area sensor 9 is used. Only the code of the irradiated portion (the code located on the straight line (marker line ef) connecting the irradiated portions of the marker light M at both ends) can be read. Therefore, the user holds the code scanner 1 and brings the reading unit 2a close to the reading object at a distance of about 80 mm, and the marker light M is applied to both ends of the specific code to be read as shown in FIG. By aligning it so that it is irradiated and operating the trigger switch 6 in that state, only the code can be read.

In this case, the user can surely perform the positioning simply by adjusting the position of the reading unit 2a so as to irradiate the marker light M to the specific code portion to be read. Unlike the case of performing the position alignment, the certainty at the time of reading a specific code located in a part of the reading field F can be improved. Although the description of the whole reading mode is omitted, in this mode, a plurality of codes in the reading field F can be read at a time.

However, since the positioning of the reading section 2a with respect to the specific code is performed by the user, there may be cases where the positioning becomes inappropriate. FIG. 2 shows an example of this. As shown in FIG. 2A, for example, the recording area of the bar code B is placed on a marker line ef that is imagined as a straight line connecting the irradiation (center) portions of the marker lights M at both ends. If it is located, the code B can be read correctly, but as shown in FIG.
If the recording area of the barcode B is completely out of the marker line ef or if a plurality of barcodes B are located on the marker line ef as shown in FIG. .

Therefore, in the present embodiment, the control device 4 determines that the marker line ef is fixedly positioned with respect to the reading field F of the area sensor 9 (in this case, the central part in the vertical direction of the reading field F in this case). When the code is read, the code recording position to be read and the marker light M are used.
Is determined correctly, that is, whether the code is correctly positioned on the marker line ef.

The flowchart of FIG. 3 shows the procedure of the determination performed by the control device 4. FIGS. 4 and 5 are diagrams for explaining the processing. In this determination process, the determination method differs depending on the type of code, and the flowchart of FIG. 3 shows both the case where the code type is a barcode B and the case where the code type is a character / symbol L for OCR reading. .

That is, when the code type is the bar code B,
First, only the first character of the bar code B (start character Cs shown in FIG. 4) is decoded (step S
1) If decoding is successful ("O" in step S2)
K "), the end points a and b of the first bar of the bar code B (FIG. 4).
(See step S3). Next, only the last character of the barcode B (the stop character Ce shown in FIG. 4) is decoded (step S4). If the decoding is successful (“OK” in step S5), the last bar of the barcode B is decoded. The end points c and d (see FIG. 4) are detected (step S6). If the decoding has failed ("NG" in step S2 or S5), the process returns to step S1.

Then, the intersection of the marker line ef with the line segment ab and the line segment cd is detected (step S7), and if the intersection exists in both the line segment ab and the line segment cd (step S8). Yes), it can be determined that the recording position of the barcode B and the irradiation position of the marker light M correspond correctly, and the barcode B surrounded by the end point abcd is decoded (step S9). When the decoding is completed, the fact is notified by a buzzer sound (step S10).

On the other hand, if the code type is OCR reading characters,
In the case of the symbol L, first, the horizontal projection component H (FIG. 5)
(See (a)) (step S11), and the character string area A is cut out based thereon (step S12). Next, a vertical projection component V (see FIG. 5A) of the character string area A is detected (step S13), and FIG.
Each character area W is cut out based on them, as shown in (b) surrounded by a square frame (step S14).

Then, it is checked whether or not the marker line ef crosses the first character area Ws and the last character area We (see FIG. 5B) (step S15). Is crossed by We (Yes in step S16), it can be determined that the recording position of the OCR reading character / symbol L and the irradiation position of the marker light M correctly correspond, and the OCR reading character / symbol is determined. L
(Step S17). When the decoding is completed, the fact is notified by a buzzer sound (step S18).

As described above, according to the code scanner 1 of the present embodiment, in the partial area reading mode, the object to be read is irradiated with the marker light M, and the marker light M in the read field F is irradiated. Since only a part of the code is read, it is easy to perform alignment when reading a specific code located in a part of the two-dimensional reading field of view F, thereby improving read reliability. An excellent effect is achieved. Moreover, in the present embodiment, it is determined whether or not the code recording position to be read and the irradiation position of the marker light M correspond to each other. Therefore, the code is correctly positioned at the portion irradiated with the marker light M. Decoding can be performed only when the data is read, and reading errors and the like can be prevented beforehand.

In the first embodiment, during the process of judging whether or not the code recording position and the irradiation position of the marker light M correspond to each other, the judgment result is changed to the irradiation form of the marker light M. It is also possible to provide a notifying means for notifying the user of the change (corresponding to claim 6).

Specifically, for example, if the code is a marker light M
(Reading field of view F) (in step S2 or S5 of the flowchart of FIG. 3, "N
G "or No in step S8 or S16), the marker LED 13 is switched from continuous lighting to blinking at short intervals, or the blinking cycle is changed depending on whether the marker LED 13 is at an appropriate position or not. , L for two-color emitting marker
Changing the color of the ED 13 or the like may be considered. According to this, the judgment result of the judging means can be informed easily with a simple configuration.

(2) Second Embodiment Next, a second embodiment (corresponding to claim 4) of the present invention will be described with reference to FIGS. In the embodiments described below, the same portions as those in the first embodiment are denoted by the same reference numerals, new drawings and detailed description are omitted, and only different points will be described.

In this embodiment, as shown in FIG. 9, three marker LEDs 21 as marker light irradiation means are provided.
A marker light M composed of a spot light is applied to the object to be read, which is located at both ends of the reading field F and at the center thereof. For the central marker M,
It is used for alignment when reading a two-dimensional code. In this case, as shown in FIG.
Reference numeral 21 is located below the area sensor 9 (the imaging lens 10), and is arranged side by side with the optical axis directed slightly obliquely upward.

Therefore, the optical axis Pa of the area sensor 9 and
An angle is generated between the marker LED 21 and the optical axis Pm, and as a result, unlike the case where the marker line is fixed as in the first embodiment, the reading target and the reading unit 2a (area sensor 9) are different from each other. The distance between the area sensors 9
The irradiation position of the marker light M with respect to the reading field of view F changes in the vertical direction. That is, when the distance between the reading target and the reading unit 2a is the reference distance 1 (80 mm),
The irradiation position of the marker light M is located at the center in the vertical direction of the reading visual field F, but when the irradiation position is farther from the irradiation position, the marker light M goes above the reading visual field F (see FIGS. 9A and 10A). Then it will go down.

In this embodiment, the position of the marker light M in the reading field F is determined based on the fact that an image is captured by the area sensor 9 while irradiating the marker light M to the object to be read. Is detected (identified), and the marker light M
The code of the portion irradiated with is read.
In this case, FIG. 10B shows the distribution of the brightness (brightness) of the image in the irradiation state of the marker light M, and the irradiation position of the marker light M is sufficiently brighter than other parts. The position of the marker light M is specified using this fact.

The specification of the position of the marker light M is realized mainly by the software configuration of the control device 4, and
The control device 4 and the like constitute marker position specifying means. The flowchart of FIG. 11 shows a processing procedure of marker position specification executed by the control device 4. FIG. 12 is a diagram for explaining the processing method.

That is, in FIG. 11, first, the marker light M
The image is captured by the area sensor 9 in a state where is irradiated (step S21), and as shown in FIG. 12A, the image is divided into a grid-like region s of n × n (for example, 16 × 16) pixels. The maximum value of the brightness in the area s is detected (Step S22). Next, a threshold value sh for binarization is obtained from the maximum value max and the minimum value min of the maximum values of the respective regions s (step S2).
3). In this case, for example, an intermediate value between the maximum max and the minimum min is set as the threshold value sh.

Then, from the maximum value of the divided area s, each area s is binarized using the threshold value sh (step S24). In this case, as shown in FIG. 12 (b), three white areas corresponding to the irradiated part of the marker light M are obtained, so that the center parts g, h, and i of these white areas are obtained, and these are determined. This is the position of the marker light M (step S25). Although not shown, after that, the marker LED 21 is turned off, and the reading of the code by the reading mechanism 3 is performed on the irradiated portion of the marker light M.

According to the second embodiment, the irradiation position of the marker light M on the reading field F of the reading mechanism 3 is changed by the change in the distance between the object to be read and the code scanner 1 (marker LED 21). Even if the situation fluctuates, it becomes possible to reliably read only the code in the portion of the reading field of view F that is irradiated with the marker light M,
As in the case of the first embodiment, it is easy to perform alignment when reading a specific code located in a part of the two-dimensional reading field F, thereby improving read reliability. Excellent effects can be obtained.

(3) Third and Fourth Embodiment FIG. 13 shows a third embodiment (corresponding to claim 7) of the present invention. Although not described in the above embodiments,
When reading the code by the reading mechanism 3 (area sensor 9), the control device 4 provides a photometric area in a part of the reading field F in order to make the difference between the black and white amplitudes at the time of the code binarization process constant. Based on the photometry result, it functions as exposure control means for executing exposure control for adjusting the illumination light amount of the illumination LED 11 and the gain of the amplifier at the time of code reading. Thus, stable decoding can be performed while eliminating the influence of disturbance light or the like.

In this embodiment, when reading only a part of codes in the reading field F (partial area reading mode),
The photometric area S is set according to the type of the code. That is, in the present embodiment, the marker light M is irradiated at three positions, that is, the left and right ends and the center of the reading visual field F. As shown in FIG. When the code is a two-dimensional code (“QR code”) Q, the marker light M at the center is positioned so as to be at the center of the code Q, and reading is performed, as shown in FIG. And OCR reading characters and symbols L
In the case of (and bar code B), the reading is performed by aligning the code L so as to be on a straight line connecting the marker lights M at both ends.

As shown in FIG. 13A, when the code is a two-dimensional code Q, the photometric area S has a square shape at the center of the reading field F (around the center marker light M). If the code is a character / symbol L (or a bar code B) for OCR reading as shown in FIG. It is set to a central horizontally long area connecting M. According to this, a portion where the codes Q and L actually exist can be set as the photometric area S, so that appropriate exposure control can be performed on a reading position where the codes Q and L to be actually read exist. The reading performance can be improved.

FIG. 14 shows a fourth embodiment (corresponding to claims 8 and 9) of the present invention. In this embodiment, similar to the second and third embodiments, three marker LEDs 21 are provided, and the marker light M composed of spot light is applied to three positions of the left and right ends and the center of the reading field F. The position of the marker light M to be irradiated is changed according to the type of the code. That is, when the code is a two-dimensional code Q, only the center marker light M is irradiated, and when the code is a character / symbol L for OCR reading or a bar code B, the marker lights M at both ends are irradiated. It has become so.

In this case, the photometric area S is changed according to the irradiation position of the marker light M. That is, when only the central marker light M is irradiated, the photometric area S is changed.
Is set in a rectangular area around the center marker light M, and when the marker lights M at both ends are irradiated, the photometric area S is set as a horizontally long area connecting the marker lights M at both ends. It has become.

According to this, as shown in FIG. 14, when the two-dimensional code Q is recorded on the surface of the object 22 to be read, only the marker light M at the center is irradiated. Therefore, it is possible to prevent a misalignment such as aligning any one of the marker lights M at the two ends with the two-dimensional code Q, thereby making it easier to perform the alignment, and further ensuring the reading of the code. Can be further increased. Further, similarly to the third embodiment, appropriate exposure control can be performed for a reading position where a code to be actually read exists, and reading performance can be improved.

Although not shown, for the same purpose, the marker light M composed of a plurality of spot lights is radiated by changing the color of the marker light M in accordance with the irradiation position. M may be green, and the marker lights M at both ends may be orange (corresponding to claim 10).
According to this, the user can discriminate the relationship between the irradiation positions of the plurality of marker lights M by color, which facilitates the alignment, and for example, a part of the code deviates from the reading field F. The effect of preventing misalignment and the like is excellent.

In the above embodiment, two or three spot lights are applied as marker lights. However, a configuration in which four or more marker lights are applied may be employed.
Instead of the spot light, for example, a horizontally long slit light may be used. The light source of the marker light is not limited to the LED, but may be a laser or the like. In addition, the marker light is not limited to being constantly emitted, and the marker light may be emitted by a user's switch operation. In this case, the trigger switch can be pressed in two steps and the first step ( It is also possible to adopt a configuration in which marker light is emitted in a so-called half-pressed state, and image reading is performed by further pressing the trigger switch.

Further, the optical information reading apparatus of the present invention is not limited to a so-called handy terminal, but is a handy type connected to a host computer, that is, it performs only image reading and performs data processing on the host computer side. May be applied to the type performed in
The configuration of the reading mechanism 3 (optical system) can be variously modified, such as using a mirror, and the present invention can be implemented with appropriate modifications without departing from the scope of the invention.

[Brief description of the drawings]

FIG. 1 is a view showing a first embodiment of the present invention and showing a relationship among a reading field, a code, and a marker light with respect to two types of codes.

FIG. 2 is a diagram showing a positional relationship between a marker line and a code recording position for three cases.

FIG. 3 is a flowchart showing a processing procedure for determining whether or not a code recording position and a marker light irradiation position correctly correspond to each other.

FIG. 4 is a view for explaining a method of determination processing in a barcode.

FIG. 5 is a diagram for explaining a method of determination processing on characters and symbols for OCR reading;

FIG. 6 is a block diagram showing an electrical configuration of the code scanner.

FIG. 7 is a longitudinal sectional side view schematically showing a configuration of a code scanner.

FIG. 8 is a front view of a reading unit showing a positional relationship between lenses of the reading mechanism.

FIG. 9 illustrates a second embodiment of the present invention, and illustrates a positional relationship between a reading field and a marker light irradiation position.

FIG. 10 is a diagram showing a relationship between a reading visual field, a code, and marker light (a) and a distribution of brightness in the reading visual field (b).

FIG. 11 is a flowchart showing a marker position specification processing procedure;

FIG. 12 is a view for explaining a method of processing for specifying a marker position;

FIG. 13 shows the third embodiment of the present invention, and shows the photometric area for two types of codes.

FIG. 14 is a view showing a fourth embodiment of the present invention and showing a relationship between a reading object and marker light.

[Explanation of symbols]

In the drawings, 1 is a code scanner (optical information reading device),
2a is a reading unit, 3 is a reading mechanism, 4 is a control device (partial reading means, mode switching means, marker position specifying means, determination means, exposure control means), 6 is a trigger switch, 9 is an area sensor, and 13, 21 are Marker LED (marker light irradiating means), M indicates marker light, B, Q, L indicate codes, F indicates reading field of view, and S indicates photometry area.

Claims (10)

[Claims] 1. An optical information reading apparatus comprising a reading mechanism including an area sensor and having a two-dimensional reading field, and reading the code in a state of being close to a reading object on which the code is recorded. A marker light irradiating means for irradiating the reading object with marker light; and a partial reading means for reading only a code of a part of the reading field of the reading mechanism irradiated with the marker light. Characteristic optical information reading device. 2. A mode switching means for switching between an entire reading mode for reading a code in the entire reading field of view and a partial area reading mode for reading only a code in a partial area of the reading field by the partial reading means, 2. The optical information reading apparatus according to claim 1, wherein the marker light irradiation unit is operated only in a partial area reading mode. 3. The marker light irradiating means is configured to irradiate at least both end portions of a horizontally long partial reading area in a reading field of the reading mechanism with marker light composed of spot light. The optical information reading device according to claim 1, wherein the marker light irradiation position is a fixed position with respect to the reading visual field. 4. A method in which an image is captured by the reading mechanism in a state where marker light is irradiated to the reading object,
4. The optical information reading apparatus according to claim 1, further comprising a marker position specifying unit that detects a position of the marker light in a reading field of the reading mechanism. 5. The optical system according to claim 1, further comprising a determination unit configured to determine whether the code recording position to be read and the marker light irradiation position correctly correspond to each other. Information reading device. 6. The optical information reading apparatus according to claim 5, further comprising a notifying unit for notifying a result of the determination by the determining unit based on a change in the irradiation form of the marker light. 7. Exposure control means for setting a photometry area in a part of the reading field of view and adjusting an illumination light amount and a gain of an amplifier at the time of code reading in accordance with the photometry result, wherein the exposure control means comprises 7. The optical information reading device according to claim 1, wherein the photometric area is changed according to a type of a code. 8. An exposure control means for setting a photometry area in a part of the reading field of view and adjusting an illumination light amount and a gain of an amplifier at the time of code reading according to the photometry result, wherein the exposure control means comprises: 8. The optical information reading device according to claim 1, wherein the photometric area is changed according to an irradiation position of the marker light. 9. The marker light irradiating means is configured to be capable of irradiating a plurality of positions with a marker light composed of spot light, and to change a position of the marker light to be irradiated according to the type of the code. 9. The method according to claim 1, wherein:
The optical information reading device according to any one of the above. 10. The marker light irradiating means is configured to irradiate a marker light composed of a plurality of spot lights,
10. The optical information reading device according to claim 1, wherein the color of the marker light is changed according to the irradiation position.