JPH0676097A - Bar code reader - Google Patents

Abstract

PURPOSE:To change the photographable range of a camera part by changing a distance between a bar code and the camera part, to maintain the illumination of the entire area of the photographable range by an illumination means uniformized at more than prescribed intensity regardless of the change of the distance and the photographable range and to surely read the bar code arranged in the photographable range. CONSTITUTION:The illumination means 32 for illuminating the bar code and the camera part 16 provided with an optical system 16 for reading bar code information from the bar code illuminated by the illumination means are mutually combined and selectively and freely movably supported by a strut between an upper position and a lower position. The plural LEDs 34 of the illumination means 32 are classified into two mutually electrically independent blocks B1 and B2 and are appropriately turned ON or OFF by the camera part 16 being arranged at the upper position and the lower position and illumination conditions for the bar code are switched.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a camera section including an illuminating means arranged apart from a bar code, an image pickup device and an optical system for forming an image of the bar code on the image pickup device. The present invention relates to a bar code reading device equipped with.

[0002]

2. Description of the Related Art In a conventional bar code reading apparatus, reflected light from a bar code illuminated by an illuminating means is imaged on an image sensor such as a CCD by an optical system in a camera section, and the bar code on the image sensor is read. A signal corresponding to an image (image information) is transmitted from the decoder to the host computer as bar code information.

In order to correctly read the bar code information from the bar code, it is important to obtain reflected light of uniform and appropriate brightness from the entire area of the bar code. Therefore, it is desired that the illumination means uniformly illuminate the entire area of the barcode with appropriate brightness.

In a conventional handy-type bar code reader of the contact type, which has a fixed focus and a fixed magnification, and a camera unit and a lighting unit are housed in an integrated housing, a bar code of a predetermined standard is used for housing. Since the barcode reading window is closely attached, the illuminating means can always illuminate the entire area of the barcode of a predetermined standard with appropriate brightness from a position separated from the barcode by a predetermined distance.

Although the contact type bar code reading apparatus is inexpensive and small in size, it is smaller than the bar code reading window and is of a predetermined standard that can be resolved by an optical system with a fixed focus and a fixed magnification when the bar code reading window is brought into close contact with the bar code reading window. There is a disadvantage that the barcode information can be read only from the barcode and that the barcode reading window must be closely attached to the barcode in order to read the barcode information.

Moreover, in recent years, as a result of the widespread use of bar codes of a predetermined standard that can be read by a contact type bar code reader, the amount of information that can be displayed by the bar code of a predetermined standard is approaching its limit. It was

On the other hand, various new bar codes capable of displaying a larger amount of information than the bar codes of the above-mentioned predetermined standards have been developed, and these new bar codes are called two-dimensional bar codes, for example. PDF417, CODE1
6K, CODE49, Datacode, etc. are known.

The external dimensions of a two-dimensional bar code vary depending on the dimensions of the module, which is the smallest unit of a bar or space, and the amount of information to be recorded. Generally, the smallest possible readable module is used to provide more information. Is desired to be displayed by a two-dimensional bar code having a smaller external dimension, but in any case, various two-dimensional barcodes having various external dimensions have been used.

The applicant of the present application changes the distance between the barcode and the camera unit in Japanese Patent Application No. 3-255556 in response to the situation in which various two-dimensional barcodes having various external dimensions have been used. By doing so, a bar code reader which can read bar code information from various two-dimensional bar codes having various outer dimensions is proposed.

[0010]

As described above, in a bar code reading apparatus capable of reading bar code information from various two-dimensional bar codes having various outer dimensions, the distance between the bar code and the camera unit changes. As a result, the photographable range of the camera section also changes, and accordingly, the brightness of the reflected light reflected from the entire area of the two-dimensional bar code and incident on the image pickup element of the camera section also changes.

Therefore, an error is likely to occur when reading the bar code information from the various two-dimensional bar codes.

The present invention has been made under the above circumstances, and an object of the present invention is to change the distance between the bar code and the camera section so as to change the photographable range of the camera section and to obtain various external dimensions. The barcode information can be read from various barcodes of the above, and the barcode illuminated by the illumination means despite the change in the image capturing range of the camera due to the change in the distance between the barcode and the camera. Provided is a bar code reading device capable of reliably reading the bar code information by maintaining the brightness of the reflected light reflected from the entire area of the camera and incident on the image pickup device of the camera unit at a predetermined intensity or more. That is.

[0013]

In order to achieve the above-mentioned object, a bar code reading apparatus according to the present invention comprises: an illuminating means arranged apart from the bar code to illuminate the bar code; A camera unit including an optical system for forming an image of the barcode on the image pickup device; selectively moving the camera unit with respect to the barcode, and selectively selecting a distance between the barcode and the camera unit. The camera unit moving means for setting; and the illumination condition switching means for switching the illumination condition of the illumination means with respect to the barcode according to the distance between the barcode and the camera part;

[0014]

In the bar code reading apparatus according to the present invention, which is configured as described above, the camera section moving means selectively moves the camera section with respect to the bar code, and the bar code and the camera section are separated from each other. When the distance between the barcodes is selectively set, the illumination condition switching means switches the illumination conditions of the illumination means with respect to the barcode according to the distance between the barcode and the camera unit, thereby changing the illumination conditions of the barcode emitted by the illumination means. It is possible to maintain the brightness of the reflected light that is reflected from the entire area and is incident on the image pickup element of the camera unit to be equal to or higher than a predetermined intensity, and to reliably read the barcode information by the camera unit.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Various embodiments of the present invention will be described in detail below with reference to the accompanying drawings. 2A and 2B
2A and 2B show two states of the bar code reader according to the first embodiment of the present invention. The bar code reader according to the first embodiment includes a base 10 and a base 1.
0 is provided with a support column 12 extending upward from the peripheral part and extending upward and downward, and a camera unit 14 fixed to the upper end of the support column 12 and extending above the upper surface of the base 10 from the upper end. .

The column 12 vertically expands and contracts between the lower end position shown in FIG. 2 (a) and the upper end position shown in FIG. 2 (b) to firmly establish the lower end position and the upper end position. It has a clamp 12a for holding.

The camera unit 14 has an optical system 16 facing the upper surface of the base 10 at the projecting end of the camera unit 14, an image pickup device 18 such as a CCD facing the projecting end at the center of the camera unit 14, and a camera. The mirror 20 that guides the light incident from the optical system 16 to the image sensor 18 at the projecting end of the unit 14, and the camera unit 1
4, a decoder 22 located farther from the projecting end than the image sensor 18 is provided.

The optical system 16 is mounted on the optical system 16 on the upper surface of the base 10 when the camera unit 14 is disposed by the support column 12 at the lower end position of FIG. 2A and the upper end position of FIG. 2B. 2 for setting two focal lengths in the optical system 16 so that the reflected light from the image located within the range of the predetermined height (focal depth) in the predetermined opposite region is formed on the image pickup device 18. It has a focal length setting knob 22.

The predetermined area facing the optical system 16 on the upper surface of the base 10 is used as the two field frames on the upper surface where the optical system 16 can form an image on the image sensor 18 at the lower end position and the upper end position. Reference numeral 24, 2 on the upper surface in FIG.
It is formed as shown with 6. Here, the larger visual field frame 24 is a visual field frame when the camera unit 14 is arranged at the upper end position, and the smaller visual field frame 26 is a visual field frame when the camera unit 14 is arranged at the lower end position.

In this embodiment, the distance from the upper surface of the base 10 to the center of the optical system 16 is set to 205 mm when the camera unit 14 is located at the upper end position, and is set to 205 mm when the camera unit 14 is located at the lower end position. The focal length of the optical system 16 is set to 25 mm. Therefore, in this embodiment, the larger field frame 24 when the camera section 14 is arranged at the upper end position is 50 mm × 3.
It has a size of 7 mm, and the smaller field frame 26 when the camera unit 14 is arranged at the lower end position has a size of 30 mm × 22 mm.

An image located on the upper surface of the base 10 within a range of a predetermined height (depth of focus) within the above-mentioned predetermined area is directly attached to the outer surface of the object 28 placed on the upper surface of the base 10. It is the barcode 30 printed on a label that is printed or affixed.

The column 12 constitutes camera section moving means for selectively moving the camera section 14 with respect to the bar code 30 and selectively setting the distance between the bar code 30 and the camera section 14.

In the camera section 14, around the optical system 16, an illuminating means 32 is attached so as to face the two field frames 24 and 26 on the upper surface of the base 10.

As shown in FIG. 1A, the illuminating means 32 has the optical system 1 with its opening facing the side opposite to the column 12.
A substantially U-shaped frame 32 arranged so as to surround 6
a, and a plurality of LEDs 34 are arranged on the lower surface of the frame 32a in substantially the same shape as the lower surface.

The opening of the frame 32a of the illuminating means 32 is directed to the side opposite to the support column 12 because of the frame 32a.
If the curved portion of a is arranged on the side opposite to the column 12, the user of the barcode reading apparatus can confirm the position of the barcode 30 on the upper surface of the base 10 from above on the side opposite to the column 12. This is because it is difficult for the bar code 30 to be placed inside either of the two field frames 24 and 26 on the upper surface, which is hindered by the curved portion.

The plurality of LEDs 34 of the illumination means 32 are substantially U-shaped.
A first block B1 composed of two linear U-shaped portions located inside and a substantially U-shaped curved portion, and two substantially U-shaped linear portions outward It is electrically separated into a second block B2 constituted by the ones indicated by the circled numbers 21 to 32 of the row located, and each block B1, B2 has a plurality of LEDs 34 in each block B1, B2. Predetermined resistance R so that rated current flows equally
1 or R2 is connected. Each block B1, B2
The resistor R1 or R2 is connected to the power supply via the three-position switch SW1.

Here, the resistance R of the first block B1
1 is connected to both the second contact and the third contact of the 3-position switch SW1, and the resistor R2 of the second block B2 is connected only to the third contact of the 3-position switch SW1.

As shown in FIGS. 2A and 2B, the operation lever 36 of the three-position switch SW1 horizontally projects from the side surface of the frame 32a of the illumination means 32.

When the operation lever 36 is operated to place the power supply side terminal at the second position, the circled number 1 in the first block B1
The rated current from the power source flows through the resistor R1 only to the LEDs 34 shown by 20 to 20, and the LEDs 34 are illuminated with the same brightness. When the operating lever 36 is operated to place the power supply side terminal at the third position, the circled numbers 1 to 2 of the first block B1
In addition to the LED 34 indicated by 0, the resistance R2 is also applied to the LEDs 34 indicated by the circled numbers 21 to 32 of the second block B2.
The rated current from the power source flows through the lights, and the lights are turned on with the same brightness. When the operation lever 36 is operated to place the power supply side terminal at the first position, the first and second blocks B
The supply of current from the power supply side to 1 and B2 is cut off, and all the LEDs 34 indicated by circled numbers 1 to 32 of the first and second blocks B1 and B2 are turned off.

In this embodiment, the LEDs 34 indicated by the circled numbers 1 to 20 of the first block B1 are as shown in FIG.
When the camera unit 14 is arranged at the lower end position, the operation lever 36 of the three-position switch SW1 is arranged at the second position, so that the small visual field frame 26 on the base 10 for the camera unit 14 at the lower end position is arranged. The orientation is adjusted so that the entire enclosed area is illuminated with a predetermined illuminance of uniform brightness.
At this time, the LEDs 34 indicated by circled numbers 1 to 20 in the first block B1 indicate to the user by light the area surrounded by the small visual field frame 26 on the base 10.

In the area indicated by this light, the object 38 is placed on the base 10 as shown in FIG.
Even if the upper small field frame 26 is covered by the object 38, it is illuminated on the upper surface of the object 38, so that the user can place the bar code 30 on the upper surface within the area indicated by the light and set the lower end position. Optical system 1 of camera section 14
If the 2 focal length setting knob 22 of 6 is arranged at a predetermined position corresponding to the lower end position, the first block B of the illumination means 32 will be described.
A bar code 3 whose entire area is illuminated by a predetermined illuminance with uniform brightness by the LEDs 34 indicated by circled numbers 1 to 20 of 1
The barcode information can be easily read by the camera unit 14 from 0.

The camera unit 14 is arranged at the above-mentioned lower end position when the external dimensions of the barcode 30 on the upper surface of the object 38 are within the range of the visual field frame 26 and the above-mentioned module has a high density.

The circled numeral 1 of such a first block B1
As shown in FIG. 3 at the same time, the LEDs 34 shown in FIG. 20 to FIG. It only illuminates the central part of the area surrounded by the large field frame 24 on the base 10 for 14. However, the second switch which is turned on only when the operation lever 36 of the three-position switch SW1 is placed in the third position
LEDs indicated by circled numbers 21 to 32 of block B2 of
34 is oriented so that it illuminates the periphery of the area of the large field frame 24, which was not illuminated by the LEDs 34 shown by the circled numbers 1 to 20 of the first block B1, with their optical axes intersecting each other. Has been done. Second block B2
The LEDs 34 indicated by the circled numbers 21 to 32 of the LED 34 are indicated by the circled numbers 1 to 20 of the first block B1.
The whole area of the large visual field frame 24 is illuminated with a predetermined illuminance of uniform brightness in cooperation with the above, and at this time, the area surrounded by the large visual field frame 24 on the base 10 is shown to the user by light. There is.

In the area indicated by this light, the object 38 is placed on the base 10 as shown in FIG.
Even when the large field frame 24 on the upper side is covered with the object 38, it is illuminated on the upper surface of the object 38, so that the user can position the bar code 30 on the upper surface within the area indicated by the light and set the upper end position. Optical system 1 of camera section 14
If the 2 focal length setting knob 22 of 6 is arranged at a predetermined position corresponding to the upper end position, the first block B of the illuminating means 32.
LED 34 and second indicated by circled numbers 1 to 20
LEDs indicated by circled numbers 21 to 32 of block B2 of
The bar code information can be easily read by the camera unit 14 from the bar code 30 whose entire area is illuminated with a predetermined illuminance by 34.

The camera unit 14 is arranged at the above-mentioned upper end position when the external dimensions of the bar code 30 on the upper surface of the object 38 are within the range of the visual field frame 24 and the module density is relatively low. .

Even when the operation lever 36 of the three-position switch SW1 is arranged at the third position and all the LEDs 34 are turned on to the illumination means 32 when the camera portion 14 is arranged at the lower end position, the upper surface of the object 38 is The bar code 30 can be arranged within the range of the small visual field frame 26.
If the reflected light from is not so bright as to make it impossible to form an image on the image sensor 18 of the camera section 14, the camera section 14 can read the bar code information from the bar code 30 within the range of the small visual field frame 26. .

As described above in detail, in the above-described embodiment, the plurality of LEDs 34 electrically divided into the first and second blocks B1 and B2 and the first and second blocks B1 and B2 are selected. The three-position switch SW1 for turning on and off the light is used for the barcode 30 and the camera unit 14.
An illumination condition switching unit that switches the illumination condition of the illumination unit 32 with respect to the barcode 30 in accordance with the distance between and is configured.

FIG. 4 schematically shows the external appearance of the bar code reading apparatus according to the second embodiment of the present invention.

In this embodiment, the column 12 protruding upward from the peripheral portion of the base 10 does not expand and contract, and the camera unit 14
Goes up and down along the column 12. A clamp 14 a for fixing the camera unit 14 to an arbitrary height on the support column 12 is provided at the base end of the camera unit 14.

Height indicators 40 are marked on the column 12 at a plurality of predetermined positions (five positions in the second embodiment of FIG. 4), and the plurality of LEDs of the illumination means 32 are the above-mentioned LEDs of the camera section 14. The same number as the plurality of positions is divided into blocks, and the plurality of LEDs in these blocks are the same number as the plurality of positions when the camera unit 14 is arranged at each of the plurality of positions. The arrangement and orientation are determined so that the entire area of each of the plurality of areas on the upper surface of the base 10 surrounded by each of the above can be illuminated with a predetermined illuminance with uniform intensity.

Further, the focal length setting knob of the optical system 16 of the camera section 14 is also a predetermined one arranged inside the corresponding visual field frame on the upper surface of the base 10 when the camera section 14 is arranged at each of the plurality of positions. 5 focal length setting knob 42 for adjusting the focal length of the optical system 16 in five steps so that an image within the height (focal depth) of the image is formed on the image sensor 18 of the camera unit 14.
And a switch for selectively turning on and off a plurality of blocks of the illuminating means 32 is also for illuminating a predetermined field frame defined by the arrangement of the camera unit 14 at each of the plurality of positions. Is configured as a five-position switch to turn on the block corresponding to, and the operating lever 44 of the five-position switch is the frame 32 of the illumination means 32.
It projects horizontally from the side surface of a.

In this embodiment, the camera unit 14 is provided with the support column 12.
When it is arranged at any of the positions indicated by the upper height index 40, the 5 focal length setting knob 42 of the optical system 16 of the camera section 14 and the operation lever 44 of the 5 position switch of the illumination means 32 are moved to the camera section 14. By arranging at the position of the value indicated by the height index 40 corresponding to any of the above positions, the visual field of the camera unit 14 set corresponding to the height position of the camera unit 14 from the upper surface of the base 10. The entire area of the upper surface surrounded by the frame can be uniformly illuminated with a predetermined illuminance by some of the plurality of blocks of the illumination means 32 corresponding to the field frame. Then, the optical system 16 forms a uniform and predetermined brightness of reflected light from the barcode arranged in the area of the upper surface surrounded by the field frame as a barcode image on the image pickup means of the camera unit 14. You can

Here, in the case where a bar code is printed or a bar code label is attached on an object whose height exceeds the depth of focus of the camera section 14 determined at the height position where the camera section 14 is held. The camera unit 14
Is increased from the height position by the amount by which the height of the object exceeds the depth of focus, the barcode on the object can be read by the camera unit 14.

As described above in detail, the height from the upper surface of the base 10 to the camera unit 14 can be changed in multiple steps. In this embodiment, the illumination condition of the illumination means 32 is changed according to the height. By doing so, irrespective of the height position of the camera unit 14, the illumination means covers the entire area of the bar code within the field frame of the camera unit 14 set on the upper surface of the base 10 corresponding to the height position. By 32, it is possible to illuminate uniformly and with a predetermined illuminance. Therefore, the barcode information can be surely read from the barcode by the camera unit 14 without error.

FIG. 5 shows a plurality of LEs of the illumination means 32 of the bar code reading apparatus according to the third embodiment of the present invention.
Another wiring for D34 is shown.

This embodiment is different from the above-mentioned wiring of the first embodiment in that the circled numbers 1 to 20 of the first block B1.
Is connected to the second contact of the three-position switch SW1 via the resistor R1 of the first embodiment described above, and the resistor R1 is larger than the resistor R1.
The only difference is that it is connected to the third contact of the three-position switch SW1 via 3.

When the operation lever 36 of the three-position switch SW1 is operated to place the terminal on the power source side at the second position, the LED 34 indicated by the circled numbers 1 to 20 of the first block B1.
The rated current from the power source flows only through the resistor R1 to light the same brightness.

When the operation lever 36 is operated and the terminal on the power source side is arranged at the third position, the circled number 1 in the first block B1
The rated current from the power source flows through the resistor R3, which has a smaller electric resistance than the resistor R1, to each of the LEDs 34 shown by 20 to 20. Each LED 34 has a larger power source side terminal than that in the second position. It is lit with brightness. further,
L indicated by the circled numbers 21 to 32 of the second block B2
The rated current from the power source also flows to the ED 34 through the resistor R2, and the ED 34 is turned on with the same brightness. When the operation lever 36 is operated and the terminal on the power supply side is placed in the first position, the first
The supply of current from the power supply side to the second and second blocks B1 and B2 is cut off, and all the LEDs 34 indicated by circled numbers 1 to 32 of the first and second blocks B1 and B2 are turned off.

The terminal on the power source side of the three-position switch SW1 is arranged in the second position when the camera section 14 is arranged in the lower end position as shown in FIG. 2A, and as shown in FIG. 2B. When it is arranged at the upper end position, it is arranged at the third position. Therefore, the camera unit 14 is arranged at the upper end position, and the bar code 30 on the object 28 on the upper surface of the base 10 from the lighting unit 32.
In the case where the distance up to is increased and the field frame is enlarged, the LED 34 indicated by the circled numbers 21 to 32 of the second block B2 for the outer peripheral portion of the field frame is turned on and the field of view is also increased. By increasing the brightness of the LEDs 34 indicated by circled numbers 1 to 20 of the first block B1 for the central portion of the frame as compared with the case where the camera unit 14 is arranged at the lower end position, It prevents the illuminance of the entire area from decreasing.

As shown in the various embodiments described above, manually changing the illumination condition of the illumination means 32 according to the distance between the camera unit 14 and the bar code 30 on the object 28 is a handy type bar. It goes without saying that it can be applied to a code reading device.

FIGS. 6A and 6B show two states of the bar code reading apparatus according to the fourth embodiment of the present invention. In this embodiment, lighting and extinguishing of the first and second blocks B1 and B2 of the plurality of LEDs 34 of the lighting means 32 are performed between the camera unit 14 and the barcode 30 on the object 28 on the upper surface of the base 10. It is different from the case of the above-mentioned first embodiment only in that it is automatically performed by the action of the distance detecting means for detecting the distance.

In this embodiment, the distance detecting means includes upper and lower limit sensors 50a and 50b arranged at two predetermined positions above and below the vertically extendable and retractable support column 12, and the camera section 14.
And a sensor operating member 52 attached movably along the support column 12 together with the camera section 14.

When the camera unit 14 is arranged at the lower end position as shown in FIG. 6A, both the upper and lower limit sensors 50a and 50b are switched on by the sensor operating member 52 attached to the camera unit 14. , Correspondingly, the first and second LEDs 34 of the lighting means 32
3-position switch S for blocks B1 and B2 (Fig. 1)
W1 is arranged in the second position. Then, only the plurality of LEDs 34 of the first block B1 are turned on to uniformly illuminate the entire region surrounded by the small visual field frame 26 on the base 10 corresponding to the camera unit 14 at the lower end position with a predetermined illuminance.

When the camera unit 14 is arranged at the upper end position as shown in FIG. 6B, the upper limit sensor 50
Only a is switched on by the sensor operating member 52 attached to the camera unit 14, and correspondingly the first and second blocks B of the plurality of LEDs 34 of the illumination means 32.
A 3-position switch SW1 for 1, B2 (FIG. 1) is placed in the third position. Then, in addition to the plurality of LEDs 34 of the first block B1, the plurality of LEs of the second block B2 are provided.
D34 is further turned on, and the entire area surrounded by the large visual field frame 24 on the base 10 corresponding to the camera unit 14 at the upper end position is uniformly illuminated with a predetermined illuminance.

The upper and lower limit sensors 50a and 50b and the sensor operating member 52 described above may be arranged in the column 12 so as not to be seen from the outside. In addition, the number of limit sensors arranged on the column 12 depends on the base 10.
It is needless to say that if the height from the upper surface of the camera unit 14 to the camera unit 14 can be changed in multiple stages, a number corresponding to the height stage of the camera unit 14 can be arranged.

Note that, for example, by configuring only the tip of the sensor operating member 52 to contact the limit sensor, the upper and lower limit sensors 50 at the lower end position.
Only the lower limit sensor 50b of a and 50b may be turned on.

FIG. 7 shows the camera unit 14 on the upper surface of the base 10.
A fifth embodiment is shown using a special bar code affixed in the area enclosed by the small field frame 26 when the is located at the lower end position.

The special bar code has a pattern that is never used normally, and is read by the camera unit 14 without being placed on the upper surface of the base 10.

In the camera section 14, after the image of the special bar code formed on the image pickup device 18 is recorded in the frame memory for the decoding process in the decoder 22, a predetermined module of the special bar code is formed. It is calculated how many (pixel / module) of a large number of pixels in the frame memory the (minimum display unit composed of a bar and a space) corresponds to. It is preferable to use a clear start code or end code in the special bar code for the predetermined module.

In FIGS. 7A and 7B, the camera unit 14 is shown.
An image 62 of the bar code recorded in the frame memory 60 when is placed at the upper end position and an image 62 of the bar code recorded in the frame memory 60 when the camera unit 14 is placed at the lower end position are shown. The camera section 14
It is shown that the outer dimensions of the barcode image 62 recorded in the frame memory 60 are larger when the camera unit 14 is arranged at the lower end position than when the camera unit 14 is arranged at the upper end position. .

The pixel / module value corresponding to the distance from the upper surface of the base 10 to the camera unit 14 is measured in advance and recorded in the processing unit of the decoder 22.
The illumination means 3 corresponding to the distance from the upper surface of the base 10 to the camera unit 14 in the processing device corresponding to the barcode image 62 recorded in the frame memory 60 immediately before the use of
It is possible to switch between the two illumination conditions.

In FIG. 8, a sixth field frame provided on the upper surface of the base 10 is used as the distance detecting means described above.
Examples of are shown.

In the camera unit 14 of this embodiment, the distance from the upper surface of the base 10 can be set in, for example, three stages, and three field frames 70a, 70b, 7 for the camera unit 14 in each stage can be set.
0c is formed on the upper surface. The higher the height of the camera unit 14, the larger the field frames 70a, 70b, 70c.

If the camera unit 14 is placed at the lower end position without being placed on the upper surface of the base 10, the camera unit 14 does not read any of the three visual field frames 70a, 70b, 70c. When the camera unit 14 is arranged in the middle position in the same state, the camera unit 14 has three field frames 70a, 70b, 70c.
The smallest field frame 70a for the camera unit 14 at the lowermost position is read by the camera unit 14, and this is read by the camera unit 1.
No. 4 decoder 22 on the frame memory in the X-axis direction and Y
When electrically scanned in the axial direction, two bars can be seen in each direction. Further, if the camera unit 14 is arranged at the upper end position in the same state, the camera unit 14 will have three field frames 70a and 7a.
Camera part 1 at the lower end position and the middle position of 0b and 70c
The smallest visual field frame 70a for 4 and the intermediate visual field frame 70b are read by the camera unit 14, and are read in the X-axis direction and the Y-axis direction on the frame memory of the decoder 22 of the camera unit 14. When scanned, four bars can be seen in each direction.

As described above, the camera unit 14 is arranged on the X-axis of the frame memory of the decoder 22 according to the distance from the upper surface of the base 10 to the camera unit 14 without being placed on the upper surface of the base 10. The number of bars to be confirmed in each of the direction and the Y-axis direction is recorded in the processing device of the decoder 22, and one or two visual field frames (70a or 70a or 70a or 70a recorded in the frame memory 60 immediately before the use of the camera unit 14 is recorded. 70a, 70
Corresponding to b), it is possible to cause the processing device to switch the illumination condition of the illumination means 32 corresponding to the distance from the upper surface of the base 10 to the camera unit 14.

In the various embodiments described above, the decoder 22
Was included in the camera unit 14, but the present invention can be applied to the case where the decoder 22 is provided independently of the camera unit 14 or the case where the decoder 22 is provided independently of the barcode reading device. Needless to say.

[0067]

As described above in detail, in the bar code reading apparatus of the present invention, it is possible to change the distance between the bar code and the camera section to change the photographable range of the camera section, and to change various outer shapes. Bar code information can be read from bar codes of various sizes, and the bar illuminated by the illumination means despite changes in the image-capable range of the camera section due to changes in the distance between the bar code and the camera section. It is possible to maintain the brightness of the reflected light that is reflected from the entire area of the code and is incident on the image pickup element of the camera unit at a predetermined intensity or more, and to reliably read the barcode information.

[Brief description of drawings]

FIG. 1 (a) is a schematic bottom view showing an array of a plurality of LEDs in an illumination means of a barcode reading device according to a first embodiment of the present invention, and FIG. FIG. 4 is a wiring diagram schematically showing a state in which a plurality of LEDs are electrically divided into independent blocks.

FIG. 2 (a) is a side view showing the barcode reading device according to the first embodiment of the present invention in a state in which a camera unit combined with an illumination unit is arranged at a lower end position;
FIG. 6B is a side view showing the barcode reading device according to the first embodiment of the present invention in a state where the camera unit combined with the illumination unit is arranged at the upper end position, and FIG. FIG. 3 is a plan view showing the field frame of the camera unit on the upper surface of the base of the barcode reading device when the bar code reader is arranged at the lower end position and the upper end position.

3 is a block diagram of a plurality of LEDs of the illumination means in the first embodiment of FIG. 1 covering the entire area of a small visual field frame for the camera unit at the lower end position and the large visual field frame for the camera unit at the upper end position; FIG. 3 is a schematic side view showing a state in which lighting conditions are selectively turned on or off to change illumination conditions in order to illuminate the entire area with a uniform predetermined illuminance.

FIG. 4 is a view showing that the height of the camera unit combined with the illuminating unit from the base can be changed in multiple stages, and the illumination condition of the illuminating unit can be changed in multiple stages corresponding to the height. The side view which shows the external appearance of the barcode reader according to the 2nd Example of this.

FIG. 5 is a wiring diagram schematically showing wiring different from that in the first embodiment of a plurality of blocks of a plurality of LEDs of an illumination means in a bar code reader according to a third embodiment of the present invention. .

FIG. 6 (a) is a fourth view of the present invention in which the illumination condition of the illumination means can be automatically switched according to the height of the camera unit combined with the illumination means from the upper surface of the base.
FIG. 9B is a side view showing the bar code reading device according to the embodiment of FIG. 7 in a state where the camera unit combined with the illumination means is arranged at the lower end position, and FIG. 9B is a bar view according to the fourth embodiment of the present invention. It is a side view which shows the code reader in the state which the camera part combined with the illumination means was arrange | positioned at the upper end position.

7 (a) and 7 (b) show that the illumination conditions of the illumination means can be automatically switched according to the height of the camera unit combined with the illumination means from the upper surface of the base. In the bar code reading apparatus according to the fifth embodiment of the invention, a special bar code used as a distance detecting means for detecting the arrangement of the camera unit at the upper end position and the lower end position is provided on the upper surface of the base unit. FIG. 6 is a schematic diagram showing a change in a state recorded in a frame memory of a decoder of a camera unit when arranged at an upper end position and a lower end position.

FIG. 8 is a view showing a sixth embodiment of the present invention in which the illumination condition of the illumination means can be automatically switched according to the height of the camera unit combined with the illumination means from the upper surface of the base. 3 is a schematic view showing three field-of-view frames used as distance detection means for detecting the arrangement of the camera unit at the upper end position, the middle position, and the lower end position in the barcode reading apparatus. FIG.

[Explanation of symbols]

12 ... Support (camera part moving means), 12a, 14a ... Clamp knob (camera part moving means), 14 ... Camera part,
16 ... Optical system, 18 ... Image sensor, 22 ... Decoder, 30
... bar code, 32 ... illumination means, 34 ... LED (illumination condition switching means), 50a ... upper limit sensor (illumination condition switching means), 50b ... lower limit sensor (illumination condition switching means), 52 ... sensor operating member (illumination) Condition switching means), 62 ... special bar code (distance detection means),
70a, 70b, 70c ... Field-of-view frame (distance detection means), B
1 ... 1st block (illumination condition switching means), B2 ... 1st block (illumination condition switching means), SW1 ... 3 position switch (illumination condition switching means).

Claims (1)

[Claims] 1. A illuminating means which is arranged apart from a bar code to illuminate the bar code; an image pickup device; and a camera section including an optical system for forming an image of the bar code on the image pickup device; A camera unit moving means for selectively moving the camera unit with respect to the code and selectively setting a distance between the barcode and the camera unit; and a bar corresponding to the distance between the barcode and the camera unit. A bar code reading device comprising: an illumination condition switching unit that switches the illumination condition of the illumination unit with respect to the code.