JP3748107B2 - Optical cord photographing device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an optical code photographing apparatus used as, for example, a photographing means of a two-dimensional code reader (reader), and more particularly to an optical code photographing apparatus suitable for photographing an optical code drawn on a mirror surface.
[0002]
[Prior art]
In a production line for industrial products such as a liquid crystal panel, a plasma display panel, and a cathode ray tube, a two-dimensional code is directly drawn on the product itself using a laser marker. Since the two-dimensional code drawn in this way has a two-dimensional code pattern made of, for example, metallic chrome on the surface of the glass plate, it will exhibit a so-called specular body, which is a conventional one that uses diffusely reflected light. Depending on the two-dimensional code photographing device, it is difficult to obtain a clear image. In view of this, the present applicant has previously proposed a two-dimensional code photographing apparatus using specularly reflected light generated on the surface of a mirror body by using a coaxial incident optical system (see Patent Document 1).
[0003]
FIG. 10 shows a configuration diagram of a conventional two-dimensional code photographing apparatus using specular reflection light. As shown in the figure, the two-dimensional code photographing device 7 includes a camera 710 with a built-in image sensor and a photographing auxiliary tool 720 attached to the tip of the camera 710. In the figure, reference numeral 2 denotes a glass plate such as a liquid crystal panel, a plasma display panel, or a cathode ray tube, 2a denotes the surface of the glass plate 2, and 2b denotes a surface 2a of the glass plate 2 using a laser marker or the like. It is a two-dimensional code that is attached.
[0004]
The camera 710 and the photographing assisting tool 720 are rotatably coupled around the optical axis 726 of the camera via a screw mount (not shown). The hood 727 is a bottomed rectangular tube whose bottom surface is open, and is optically coupled to the camera 710 through a light introduction hole. The optical axis of the optical system introduced into the camera represented by the lens 723 is aligned coaxially with the optical axis 726 of the camera. A selective optical component (polarizing beam splitter, half mirror, etc.) 722 is disposed in front of the optical axis of the lens 723 (downward in the drawing) with the reflecting surface inclined at an angle of 45 degrees. An illuminator 721 is disposed at a position that is a predetermined distance away in the direction. As the illuminator 721, a monochromatic light source such as a red light emitting diode is used, and thereby monochromatic light is emitted. The illumination light 724 emitted from the illuminator 721 in the horizontal direction is reflected downward by the lower surface of the selective optical component 722. Therefore, the two-dimensional code 2b is illuminated from directly above by the illumination light 724 from the illuminator 721. The specularly reflected light 725 reflected by the mirror surface composed of the surface 2a of the glass 2 and the two-dimensional code 2b travels directly upward, passes through the selective optical component 722, and enters the lens 723. The As described above, since the optical axis of the optical system represented by the lens 723 and the optical axis 726 of the camera 710 are coaxially aligned, the camera 710 can obtain the two-dimensional code 2b from directly above. Video is output.
[0005]
[Patent Document 1]
JP 2002-269490 A
[0006]
[Problems to be solved by the invention]
However, in the conventional two-dimensional code photographing apparatus shown in FIG. 10, in a production line such as a liquid crystal panel and a plasma display panel, a transparent thin film is often formed on the surface 2a of the glass 2 and the surface of the two-dimensional code 2b. (For example, the material is polyimide), it has been pointed out that the two-dimensional code reading is hindered by the interference of light.
[0007]
FIG. 11 shows an operation explanatory diagram of the optical system of the conventional apparatus. In the figure, 2 is a glass plate, 21 is a transparent thin film, 721 is an illuminator, L0 is irradiation light emitted from the illuminator 721, L1 is reflected light from the surface 2a of the glass plate 2, and L2 is the surface of the thin film 21. The reflected light by 21 a, n is the refractive index of the thin film 21, and d is the thickness of the thin film 21.
[0008]
As apparent from the figure, when the coaxial epi-illumination optical system is used, the irradiation light L0 and the reflected light L1 and L2 are coaxial, so that the change in the thickness of the thin film 21 is based on the phase difference between these lights. As a result, local light strengthening and weakening occur, and as a result, so-called interference action causes local light and darkness on the two-dimensional code, which causes trouble in decoding the two-dimensional code. The
[0009]
Further, in the conventional two-dimensional code photographing device, a monochromatic light source such as a red light emitting diode is employed as the illuminator 721, and the irradiation light 724 from the illuminator 721 is a half mirror or a polarized beam. It is difficult to introduce specularly reflected light 725 having a sufficient amount of light to the camera 710 because it attenuates at the time of reflection and transmission of the selective optical component 722 such as a splitter.
[0010]
The present invention has been made paying attention to the problems in such a conventional optical code (for example, two-dimensional code) photographing apparatus, and the object of the present invention is drawn on a mirror surface and transparent. It is an object of the present invention to provide an optical code photographing device capable of acquiring a clear image with little noise and less interference, even with an optical code on which a thin film is attached.
[0011]
Another object of the present invention is when light absorption occurs due to a high color density of a thin film deposited on an optical code (for example, a barcode or a two-dimensional code) as a subject. Even so, an object of the present invention is to provide an optical code photographing device capable of acquiring an image having clear contrast by introducing regular reflected light having a sufficient amount of light into a camera.
[0012]
Another object of the present invention is to allow the field of view to be accurately adjusted to a specific point on the subject, regardless of the angle at which the rotational tightening position is set, when the photographing auxiliary tool is attached to the camera. Another object is to provide an optical code photographing device.
[0013]
Another object of the present invention is to provide an optical code photographing device that can be arbitrarily switched between a diffuse reflection light utilization type and a regular reflection light utilization type only by performing a simple switching operation. It is in.
[0014]
Other objects and operational effects of the optical code photographing apparatus according to the present invention will be easily understood by those skilled in the art by referring to the description of the following specification.
[0015]
[Means for Solving the Problems]
The optical code photographing apparatus of the present invention has a camera with a built-in image sensor and a photographing auxiliary tool attached to the tip of the camera. Here, a typical example of the image sensor is a CCD element.
[0016]
An imaging aid includes a hood that blocks outside light, an illuminator that illuminates a subject located at a predetermined distance in front of the camera obliquely from a direction different from the optical axis of the camera, and an incident axis to the camera that is the optical axis of the camera. It includes a regular reflection light guide optical system that guides the regular reflection light from the subject around the camera so as to be coaxial.
[0017]
According to such a configuration, the reflected light introduced into the camera is a specularly reflected light obtained by irradiating the subject obliquely, so that the two-dimensional code is made of metal chromium on the glass plate as the subject. Even if the surface is covered with a two-dimensional code and has a transparent thin film, the reflected light on the glass plate surface and the reflected light on the thin film surface are not coaxial. As a result, a clear optical code image with less noise that is not affected by interference fringes or the like is obtained. With such a video, the semantic content of the optical code can be accurately decoded through subsequent image processing and decoding processing. In addition, since there are no half mirrors and beam splitters, there is little attenuation of light and a sufficient amount of light can be obtained.
[0018]
In a preferred embodiment of the present invention, the specular reflection light guiding optical system includes a coaxial matching mirror that is on the optical axis of the camera and reflects the specular reflection light from the subject that arrives via the detour optical path toward the camera. May be included. According to such a configuration, when the optical axis of the specularly reflected light incident on the camera and the optical axis of the camera coincide with each other, for example, when a screw mount is used for coupling the camera and the photographing aid, Even during rotation during tightening, the field of view of the camera is always maintained in a state where the target is aimed at a certain subject, so that it is easy to aim at the subject.
[0019]
In a preferred embodiment of the present invention, the coaxial matching mirror may be projected and retracted on the optical axis of the camera. According to such a configuration, in the state where the coaxial matching mirror is present, the subject can be photographed using the specularly reflected light, while in the state where the coaxial matching mirror is not present, the subject is photographed using the diffuse reflected light. Therefore, it is possible to always select the optimum photographing environment depending on whether the surface property of the subject is a mirror body or a diffuser.
[0020]
The present invention viewed from another aspect can be understood as an optical code reader for mirror bodies. This optical code photographing device corresponding to a specular body is extracted via an illuminator that illuminates a subject from obliquely above, a regular reflection light extraction optical system that extracts regular reflection light from the subject, and a regular reflection light extraction optical system. And an image sensor that receives regular reflection light and converts it into an electrical signal.
[0021]
According to such a configuration, there is a two-dimensional code formed by depositing metallic chrome on a glass plate, and even in a situation where a transparent thin film is deposited thereon, The optical axis of the thin-film surface reflected light and the optical axis of the glass plate surface reflected light are slightly shifted and do not coincide with each other. There is no local brightness or darkness.
[0022]
In the optical code photographing apparatus of the present invention described above, it is preferable to employ an illuminator that emits white light. According to such a configuration, since it is white light, it includes a wide frequency component, so that light interference is unlikely to occur.
[0023]
DETAILED DESCRIPTION OF THE INVENTION
In the following, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings. Note that the embodiments described below are merely examples of the present invention, and it goes without saying that the scope of the present invention is defined only by the wording of the claims.
[0024]
A block diagram of a two-dimensional code photographing apparatus according to the present invention is shown in FIG. The two-dimensional code photographing apparatus 1 includes a camera 110 with a built-in image sensor and a photographing auxiliary tool 120 attached to the tip of the camera 110. A so-called screw mount is used as the mount portion 112 that couples the camera 110 and the photographing aid 120. This screw mount is rotatable around the optical axis 111 of the camera and is fixed by screwing to a predetermined depth.
[0025]
In this example, a subject having a two-dimensional code 2b drawn with a laser marker on the surface 2a of the glass plate 2 is employed as the subject. Metal chrome is used as the material of the two-dimensional code 2b. Therefore, this subject functions as a mirror surface as a whole. In addition, as the glass plate 2, glass parts, such as a liquid crystal panel and a plasma display panel, correspond to this. In addition, in a production line for these liquid crystal panels, plasma display panels, etc., a transparent thin film may be further deposited thereon. The material of the thin film is, for example, polyimide. As described above with reference to FIG. 10, in the case of a two-dimensional code photographing apparatus employing a coaxial incident type optical system, this thin film is damaged, and the image of the two-dimensional code 2b is localized by the interference of light. Light and dark.
[0026]
Next, the configuration of the photographing auxiliary tool 120 will be described. The imaging assistance tool 120 has a hood 128 that blocks outside light. The hood 128 is a bottomed rectangular tube whose bottom surface is open. In the figure of the hood 128, an opening that communicates between the camera 110 side and the photographing auxiliary tool 120 side is formed on the upper end surface. Through this opening, the optical system in the camera 110 and the optical system in the photographing auxiliary tool 120 are optically coupled.
[0027]
In the hood 128, an illuminator 121 that illuminates the two-dimensional code 2b, which is a subject, obliquely from above is disposed. A white light emitting diode is used as a light source of the illuminator 121. Therefore, the irradiation light 122 emitted from the illuminator 121 becomes white light having a wide spectrum component.
[0028]
The irradiation light 122 emitted from the illuminator 121 is specularly reflected obliquely upward on the two-dimensional code 2b and the surface 2a of the glass plate 2 that are subjects. The first mirror 124 is disposed on the optical axis extension line of the regular reflection light 123 obtained in this way. On the other hand, a lens 126 and a second mirror 125 are disposed on an extension line of the optical axis 111 of the camera 110. The optical axis 127 of the lens 126 and the optical axis 111 of the camera 110 are aligned coaxially. Further, the specularly reflected light 123 reflected by the first mirror 124 travels toward the second mirror 125, and then is reflected by the second mirror 125 and travels toward the lens 126. That is, in the second mirror 125, the optical axis of the regular reflection light from the two-dimensional code 2b, the optical axis 127 of the lens 126, and the optical axis 111 of the camera 110 are all aligned coaxially. In other words, the first mirror 124, the second mirror 125, and the lens 126 allow the camera 110 to reflect the regular reflected light from the subject so that the incident axis to the camera 110 is coaxial with the optical axis 111 of the camera. A regular reflection light guiding optical system for detouring to the side is provided.
[0029]
In the image obtained from the camera 110 in this state, as shown in FIG. 2, the incident point on the subject (two-dimensional code 2 a) of the optical axis 122 a of the irradiation light 122 is positioned on the extension line of the optical axis 111 of the camera. In the state (in other words, the state where the subject exists at the planned shooting distance), the subject located directly below the camera 110 corresponds to the position of the first mirror 124, that is, the state viewed obliquely from above. Therefore, even if both of them rotate via the screw mount in order to attach the photographing auxiliary tool 120 to the camera 110, the image position always corresponds to the subject located directly below the camera 100, although the image rotates slightly. Therefore, there is an advantage that the field of view is easy to match.
[0030]
In addition, since the illuminator 121 is irradiated with illumination light 122 that is white light including a wide frequency component, even if a thin film is deposited on the surface of the two-dimensional code 2b, light interference hardly occurs. There is. In addition, even when the color density of the thin film deposited on the surface of the two-dimensional code 2b is high, the irradiation light 122 includes a wide spectrum component, so that the light amount is reduced for a small number of the spectrum components. Even if there is, there will be a slight decrease in the amount of light of the specularly reflected light 123, and specularly reflected light with a sufficient amount of light will be introduced into the camera 110, so that a clear image with high contrast is obtained from the camera 110. be able to.
[0031]
Next, an equivalent configuration diagram of the optical system of the device of the present invention is shown in FIG. In the figure, 121 is an illuminator, 126 is a lens, and 113 is an image sensor built in the camera 110. If the angle formed by the optical axis 122a of the emitted light emitted from the illuminator 121 and the optical axis 111 of the camera 110 is θ, the angle formed by the optical axis 123a of the specularly reflected light and the optical axis 111 of the camera 110 is also θ. Become. That is, the optical axis 122a of the irradiation light and the optical axis 123a of the regular reflection light are symmetrical with respect to the optical axis 111 of the camera 110. Also, the optical axis 123a of the regular reflection light and the optical axis 127 of the lens 126 are aligned coaxially. Therefore, an image obtained by viewing the two-dimensional code 2b, which is a subject, from the diagonally upper right is formed on the image sensor 113 built in the camera 110. It will be understood that the image generated on the light receiving surface of the image sensor 113 is based on the specularly reflected light from the mirror body, so that a clear image with high contrast can be obtained.
[0032]
Next, FIG. 3 shows an operation explanatory diagram of the optical system of the device of the present invention. In the figure, 2 is a glass plate, 2a is the surface of the glass plate, 2b is a two-dimensional code formed on the surface of the glass plate, 21 is a thin film deposited on the surface of the glass plate 2, and d is the thickness of the thin film. , 121 is an illuminator, L0 is irradiation light emitted from the illuminator 121, L1 is reflected light obtained by being reflected by the surface of the thin film 21, and L2 is obtained by being reflected by the two-dimensional code 2b on the glass plate 2. Reflected light.
[0033]
As is apparent from the figure, the reflected light L1 on the surface of the thin film 21 and the reflected light L2 reflected by the two-dimensional code 2b formed on the upper surface of the glass plate 2 are not coaxial, so there is a phase difference between them. Even if there is, the influence of the light interference is small, and as a result, the influence of the local contrast based on the interference is reduced.
[0034]
That is, as described above with reference to FIG. 11, in the two-dimensional code photographing apparatus employing the coaxial incident optical system, the reflected light L1 reflected on the surface of the glass plate and the surface of the thin film are reflected. Since the reflected light L2 is almost coaxial, the light is strengthened or weakened due to the phase difference between the two, and the interference effect causes local brightness and darkness. Since L0 illuminates the subject at an angle, the reflected light L1 and L2 of the two systems caused by reflection are not coaxial, and as a result, local light and darkness on the image due to light interference is reduced. .
[0035]
Next, FIG. 4 is a diagram for explaining the operation of the mirror in / out operation. As described above with reference to FIG. 1, the second mirror 125 has a function of coaxially aligning the optical axis of the regular reflection light obtained from the subject and the optical axis 111 of the camera 110. In this embodiment, the function of the second mirror 125 can be selectively enabled or disabled by allowing the second mirror 125 to appear and retract.
[0036]
More specifically, the second mirror 125 having a coaxial matching function is realized as a mirror support plate 125A. The mirror support plate 125A is formed of a transparent rectangular acrylic plate, and includes a mirror region 125a, a transparent region 125b, and an operation unit 125c. Then, as shown in FIG. 4B, when the mirror support plate 125A is inserted through an oblique slit opened to the side of the hood 128, the mirror region 125a appears on the optical axis 111 of the camera. On the other hand, as shown in FIG. 4C, when the mirror support plate 125A is removed from the slit 128a, the mirror region 125a does not exist on the optical axis 111 of the camera.
[0037]
An explanatory view showing another embodiment of the mirror support plate is shown in FIG. In the mirror support plate 125A shown in this embodiment, operation portions 125g and 125f are provided at both ends of an acrylic plate having an elongated rectangular shape, and in the middle region thereof, a mirror region 125d and a transparent region 125e are provided. Is provided. Then, similarly to the above, the mirror region 125d is spanned between two slits 128a provided opposite to each other across the center of the hood 128 and slid in either direction of the operation portion 125g or 125f. Alternatively, the transparent area 125e is made to appear and disappear on the optical axis of the camera 11. Even with such a configuration, the function of the second mirror 125 can be enabled or disabled by selectively making the second mirror 125 appear and disappear on the extended line of the optical axis of the camera 111.
[0038]
Next, FIG. 6 shows an explanatory diagram of the action associated with insertion / extraction of the mirror support plate. As shown in FIG. 5A, in the inserted state of the mirror support plate, the two-dimensional code photographing apparatus 1 of the present invention functions as an optical system using specular reflection light. Therefore, this is suitable when the subject is a mirror body. On the other hand, as shown in FIG. 5B, in the state where the mirror support plate is removed, the two-dimensional code photographing apparatus 1 of the present invention is in a state where the second mirror 125 does not function, so that diffuse reflection is performed. It will function as a light utilization type optical system. Therefore, it is suitable for a diffuse reflection type subject. In addition, as is apparent from a comparison between the two, the case of functioning as a specular reflection-use optical system shown in FIG. 5A and the diffuse reflection light-use optical system shown in FIG. The distance to the subject changes by d2. Therefore, an optimal optical system can be selected according to not only the properties of the subject surface but also the size of the subject.
[0039]
Next, a block diagram of the entire two-dimensional code reading system including the apparatus of the present invention is shown in FIG. In the figure, 1 is a two-dimensional code photographing device of the present invention, 2 is a controller that functions as a processing device for processing a photographed video signal, 3 is a programmable controller that operates based on the result of decoding the two-dimensional code, and 4 is a programmable controller. A host device (such as a personal computer) that gives various instructions to 5 is a handy console for manually instructing various operations to the controller 2, and a monitor 6 displays processing results of the controller 2.
[0040]
Thus, by using the two-dimensional code photographing apparatus 1 of the present invention, a clear two-dimensional code image signal with high contrast is generated, and the controller 2 processes this to perform high-precision code decoding processing. The production line can be controlled in various ways via the programmable controller 3 or the like depending on the result of the decoding.
[0041]
Next, a block diagram schematically showing an electrical configuration including the photographing apparatus 1 and the processing apparatus (controller 2) is shown in FIG. As shown in the figure, the photographing apparatus 1 is provided with a lens 126, an image sensor 113, and an illuminator 121, and the illuminator 121 is driven by an appropriate trigger signal. The object 130 is illuminated by the irradiation light emitted from the illuminator 121. The specularly reflected light generated thereby is guided to the image sensor 113 through the lens 126. For example, a CCD or the like is used as the image sensor 113. The video signal obtained from the image sensor 113 is sent to the processing device 2 (controller). In the processing device 2, the video signal is AD converted by the A / D converter 21, sent to the image processing unit 22, appropriately processed, and then sent to the data processing unit 23 for two-dimensional processing. It is used for various data processing such as code decoding. Thus, the data processing unit 23 sends the data output 24, the parallel output 25, and the monitor output 26 to the outside.
[0042]
By the way, since the optical system employed by the photographing apparatus 1 of the present invention photographs a subject from obliquely above, naturally there is a perspective projection distortion in the field of view. An explanatory diagram of a two-dimensional code image acquired by the device of the present invention is shown in FIG. As shown in FIG. 6A, the camera is placed directly above the two-dimensional code 2b that is the subject, with its optical axis facing down, and in this state, the camera 110 and the photographing aid are indicated by the arrows in the figure. Rotate as shown.
[0043]
Assuming that the two-dimensional code 2b as the subject is photographed from directly above, the video 31 becomes a square image without distortion as shown in FIG. In the case of shooting from diagonally above, as shown in the image 32, if X is taken from diagonally above in the axial direction of either X or Y, as shown in FIG. The image expands and contracts only in the axial direction. Here, the X and Y axes are two orthogonal axes that pass through the center of the two-dimensional code and are parallel to the vertical and horizontal sides of the two-dimensional code.
[0044]
On the other hand, as shown in FIG. 4D, when the image is taken from diagonally above in directions other than the X and Y axes, the two-dimensional code figure is like a rhombus as shown in the video 33. It becomes. However, as shown in FIG. 9C or FIG. 9D, even if the two-dimensional code is distorted, the positions of white cells and black cells of the two-dimensional code are recognized and read and decoded based on the finder pattern. No problems will arise. This type of processing can be easily realized by those skilled in the art.
[0045]
As is clear from the above description, according to the two-dimensional code photographing device in this embodiment, the subject is illuminated obliquely from above, while the regular reflection light is photographed from obliquely upward in the opposite direction. Therefore, even when applied to a subject having a transparent thin film on a mirror surface, as described with reference to FIG. 3, the reflected lights L1 and L2 of each layer are not coaxial, and therefore, due to light interference. The generation of local light and darkness can be suppressed, and a clear image with less noise can be obtained.
[0046]
In addition, since white light is used as a light source, light interference is less likely to occur than in the case of monochromatic light, and even when the color density of the two-dimensional code is dark (for example, blackish) As in the case of the light source using the monochromatic light, there is no significant reduction in the amount of reflected light, and this makes it possible to obtain a clear image with high contrast.
[0047]
Further, as shown in FIG. 1, the camera 110 and the photographing assisting tool 120 are coupled to be coaxially rotatable via a screw mount, and the regular reflection light 123 obtained from the subject is bypassed by the first mirror 124. After that, if the second mirror 125 provided on the optical axis 111 of the camera is bent and coaxially aligned with the optical axis of the lens 127 and the camera 111, the camera 110 and the photographing auxiliary tool 120 rotate coaxially with each other. However, since the field of view of the camera is always located directly below the optical axis 111, the field of view does not move greatly although it rotates, and there is an advantage that it is easy to accurately match the field of view of the camera.
[0048]
Further, as shown in FIGS. 4 and 5, if a coaxial matching mirror (second mirror) 125 is configured to be movable in and out of the optical axis 111 as the mirror support plate 125A, the specular reflection light utilizing optical system and the diffuse reflection light are used. The usage-type optical system can be selectively switched, and the degree of freedom of shooting conditions for the subject can be improved.
[0049]
In the above embodiment, a light source including only a white light emitting diode is used as the light source. However, the light source includes four types of light emitting diodes of a white light emitting diode, a red light emitting diode, a blue light emitting diode, and a green light emitting diode. If one is used and one or more of the light emitting diodes are selectively lit, it is possible to deal with a wide range of workpieces (or optical codes) having various surface properties.
[0050]
【The invention's effect】
As is clear from the above description, according to the present invention, a two-dimensional code is drawn on a mirror body and a subject having a transparent thin film thereon is also subjected to light and darkness due to light interference. A clear image signal with high contrast and high contrast can be obtained.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of a two-dimensional code photographing apparatus according to the present invention.
FIG. 2 is an equivalent configuration diagram of an optical system of the device of the present invention.
FIG. 3 is an operation explanatory diagram of an optical system of the device of the present invention.
FIG. 4 is an explanatory diagram of the action of the mirror in / out operation.
FIG. 5 is an explanatory view showing another embodiment of the mirror support plate.
FIG. 6 is an explanatory diagram of an action accompanying insertion / removal of a mirror support plate.
FIG. 7 is a block diagram of the entire two-dimensional code reading system including the apparatus of the present invention.
FIG. 8 is a block diagram schematically showing an electrical configuration including a photographing device and a processing device.
FIG. 9 is an explanatory diagram of a two-dimensional code image acquired by the device of the present invention.
FIG. 10 is a configuration diagram of a conventional two-dimensional code photographing device.
FIG. 11 is a diagram illustrating the operation of an optical system of a conventional device.
[Explanation of symbols]
1 Two-dimensional code photographing device
2 Glass plate
2a Surface
2b Two-dimensional code
3 Programmable controller
4 Host device
5 Handy console
6 Monitor
7 Two-dimensional code photographing device
11 Trigger signal generator
21 A / D converter
22 Image processing unit
23 Data processing section
24 Data output
25 Parallel output
26 Monitor output
31 Two-dimensional code image taken from directly above
32 Two-dimensional code image obtained from diagonally above in the axial direction of either X or Y
33 Two-dimensional code image obtained by photographing from diagonally above in directions other than the X and Y axes
110,710 camera
110a Electric cord
120,720 Shooting aid
111,726 Optical axis of camera
112 Mount part
121,721 Illuminator
122,724 Irradiation light
122a Optical axis of irradiation light
123,725 Regular reflection light
123a Optical axis of specular reflection light
124 First mirror
125 Second mirror (coaxial matching mirror)
125A Mirror support plate
125a, 125d mirror area
125b, 125e Transparent area
125a slit
125g, 125f operation unit
126,723 lens
127 Optical axis of lens
128,727 hood
722 Selective optics (half mirror or polarizing beam splitter)
d Thin film thickness
L0 irradiation light
L1 Light reflected from thin film surface
L2 Reflected light on glass surface

Claims (1)

It has a camera with a built-in image sensor and a shooting aid attached to the tip of the camera,
  Shooting aid is
  A hood that blocks outside light, an illuminator that illuminates a subject located at a predetermined distance in front of the optical axis of the camera obliquely from a direction different from the optical axis of the camera, and specularly reflected light obliquely reflected by the subject surface to the camera And a specular reflection light guiding optical system that bypasses and guides
  The specular reflection light guiding optical system
  A coaxial matching mirror that is on the optical axis of the camera and reflects specularly reflected light from the subject coming through the detour optical path toward the camera;
  A coaxial matching mirror can be projected and retracted on the optical axis of the camera.
  An optical code photographing device.

Images