JP6088957B2 - Imaging apparatus and object recognition scanner - Google Patents

Description

  Embodiments described herein relate generally to an imaging apparatus and an object recognition scanner.

  There has been proposed a product recognition apparatus that recognizes a product by extracting and analyzing a barcode from an image obtained by imaging the product with an imaging unit using a charge coupled device (CCD) or a complementary metal-oxide semiconductor (CMOS), or by object recognition. .

  In this type of product recognition apparatus, a light source may be provided inside a housing that houses an imaging unit, and the product may be illuminated by light emitted from the light source.

  In the product recognition apparatus configured as described above, the light emitted from the light source may be reflected by the inner wall of the housing and enter the imaging unit. When such reflected light is incident, the image quality of the product is lowered, and the recognition accuracy may be lowered. In particular, in object recognition for recognizing an object, it may be necessary to distinguish a subtle difference in product characteristics. It is effective to improve the recognition accuracy that a product can be imaged with high image quality.

  Under such circumstances, it has been desired to suppress the incidence of extra light and to image products with high image quality.

JP 2002-176199 A JP2013-89085A

  The problem to be solved by the present invention is to provide an imaging device and an object recognition scanner capable of suppressing the incidence of extra light and imaging a product with high image quality.

The imaging apparatus of the embodiment includes a housing, a substrate, a light emitting device, an imaging device, and a light shielding member. The housing forms an imaging window on one side. The substrate is disposed inside the housing, and at least a part of the surface facing the imaging window is treated to prevent light reflection. The light emitting device is attached to the substrate and emits illumination light through the imaging window to the outside of the housing. The imaging device images an object illuminated by illumination light through an imaging window. The light shielding member is provided inside the housing, and prevents at least part of the reflected light from entering the imaging device without passing through the imaging window without interfering with imaging.

1 is an external view of a store system including a product recognition device according to an embodiment. FIG. 2 is a diagram illustrating a partially broken structure of the imaging unit in FIG. 1. The top view which shows a mode that the light-shielding plate in FIG. 2 was seen from the left side in FIG. The block diagram of the electrical element in the goods recognition apparatus 100. FIG.

  Hereinafter, embodiments of an imaging apparatus and an object recognition scanner including the imaging apparatus will be described with reference to the drawings. This embodiment is a case where the present invention is applied to a vertical product recognition apparatus installed on an accounting counter provided in a store such as a supermarket.

  FIG. 1 is an external view of a store system including a product recognition apparatus according to this embodiment. This store system includes a merchandise recognition device 100 and a POS (point of sales) terminal 200. The merchandise recognition apparatus 100 is attached on the accounting counter 300. The POS terminal 200 is installed on the drawer 500 placed on the cash register 400. The product recognition apparatus 100 and the POS terminal 200 are electrically connected by a communication cable (not shown). An automatic change machine may be installed in place of the drawer 500.

  The product recognition apparatus 100 includes a housing 101, a keyboard 102, a touch panel 103, a customer display 104, and an imaging unit 105.

  The housing 101 has a flat box shape and stands on the accounting counter 300. The housing 101 supports the keyboard 102, the touch panel 103, and the customer display 104 at the upper end, and supports the imaging unit 105 inside. The housing 101 has a reading window 101 a facing the imaging unit 105. The imaging unit 105 images an object (object) located in the imaging area in front of the reading window 101a through the reading window 101a.

  The POS terminal 200 includes a housing 201, a keyboard 202, an operator display 203, a customer display 204, and a printer 205.

  The housing 201 supports the keyboard 202 with a part of the keyboard 202 exposed to the outside, supports the operator display 203 and the customer display 204 positioned outside, and supports the printer 205 inside.

  The accounting counter 300 includes an elongated top plate 300a. The accounting counter 300 divides the customer passage (the back side in FIG. 1) and the operator space (the front side in FIG. 1) along the longitudinal direction of the top board. The housing 101 is positioned substantially at the center in the longitudinal direction of the top board 300a, and the keyboard 102, the touch panel 103, and the reading window 101a are directed to the operator space side, and the customer display 104 is directed to the customer passage side. The top surface of the top board 300a is divided into an upstream area and a downstream area in the customer movement direction with the product recognition apparatus 100 interposed therebetween. The upstream area is used as a space for placing products that are not registered for sales among products that the shopper intends to purchase. The downstream area is used as a space for placing products for which sales have been registered.

  The cash register 400 is located on the operator space side so as to be aligned with the end of the counter counter 300 on the downstream side with respect to the moving direction of the customer in the customer passage.

  FIG. 2 is a partially broken view showing the structure of the imaging unit 105.

  The imaging unit 105 includes a housing 105a, substrates 105b and 105c, an imaging device 105d, light emitting devices 105e and 105f, and a light shielding plate 105g.

  The casing 105a has a cross section in which two opposing surfaces are a first opening OP1 and a second opening OP2, and the cross-sectional area gradually decreases from the first opening OP1 to the second opening OP2. Has a rectangular tube shape. A reading glass 101a is formed by attaching a transparent glass plate or an acrylic plate to the first opening OP1.

  The substrate 105b is attached to the housing 105a so as to substantially block the second opening OP2. An imaging device 105d, a light emitting device 105e, and the like are attached to the substrate 105b. In the substrate 105b, the region exposed to the internal space in the plane facing the internal space of the housing 105a is subjected to reflection reduction processing. How to reduce reflection, such as coloring with a color with low light reflectance (for example, matte black), application of a material with low light reflectance (light absorber), mechanical processing such as forming irregularities Various methods may be used. Further, it is desirable to erase the silk letters formed on the substrate as much as possible. Of the information displayed in silk characters, information that needs to be readable can be displayed by, for example, engraving. Such a substrate 105b corresponds to a first substrate.

  The substrate 105c is attached to a position near the first opening OP1 on the ceiling of the housing 105a. A light emitting device 105f and the like are attached to the substrate 105c.

  The imaging device 105d includes an image sensor such as a CCD and a lens system that forms an optical image of a product incident from a reading window on the image sensor, and generates image data representing the product.

  As the light emitting devices 105e and 105f, known devices such as LEDs (light emitting diodes) can be used. Each of the light emitting devices 105e and 105f irradiates light to the outside of the housing 105a through the reading window 101a. As a result, the light emitting devices 105e and 105f illuminate the merchandise worn in front of the reading window 101a. In addition to the two illustrated, the two light emitting devices 105e are similarly arranged on the opposite side across the imaging device 105d. The light emitting devices 105f are arranged side by side in the depth direction of FIG. Of course, the number and arrangement of the light emitting devices 105e and 105f may be arbitrary. For example, the light emitting device 105e corresponds to a first light emitting device, and the light emitting device 105f corresponds to a second light emitting device.

  The light shielding plate 105g is fixed to the housing 105a in the internal space of the housing 105a so as to be substantially parallel to the reading window 101a.

  FIG. 3 is a plan view showing a state where the light shielding plate 105g is viewed from the left side in FIG.

  The light shielding plate 105g is transparent and is configured by forming a substantially rectangular opening OP3 near the center of a rectangular plate and forming a light shielding region as shown by hatching. As the material for the plate, acrylic is suitable, but any material may be used as long as it is a transparent material. Areas other than the opening OP3 and the light shielding area in the light shielding plate 105g transmit light. Incidentally, the side of the opening OP3 in FIG. 3 forms a slope SL in which the interval is narrowed from the left side to the right side in FIG.

  The position and size of the opening OP3 are determined so that light coming from within a predetermined field of view enters the imaging device 105d without being blocked.

  The light shielding region is processed so as to block light transmission and reduce reflection. As the processing, any method such as coloring with a color with low light reflectance, application of a material with low light reflectance (light absorber), or mechanical processing such as forming irregularities may be used. . The light shielding area is determined so that the light emitted from the light emitting device 105e reaches the product hung in front of the reading window 101a with a sufficient amount of light to illuminate the product. The light shielding area cuts off the light path so that the reflected light does not enter the imaging device 105d. Thus, the light shielding plate has a function as a light shielding member.

  FIG. 4 is a block diagram of electrical elements in the product recognition apparatus 100. 4 that are the same as those shown in FIGS. 1 and 2 are given the same reference numerals.

  In addition to the keyboard 102, the touch panel 103, the customer display 104, the imaging device 105d, and the light emitting devices 105e and 105f, the merchandise recognition apparatus 100 includes a CPU (central processing unit) 106, a ROM (read-only memory) 107 as electrical elements. , RAM (random-access memory) 108, keyboard interface (keyboard I / F) 109, panel interface (panel I / F) 110, display interface (display I / F) 111, imaging interface (imaging I / F) 112, A drive unit 113, a POS terminal interface (POS terminal I / F) 114, and a bus line 115 are included. The bus line 115 includes an address bus, a data bus, and the like, and connects the CPU 106, ROM 107, RAM 108, keyboard interface 109, panel interface 110, display interface 111, imaging interface 112, and POS terminal interface 114 to each other.

  The keyboard 102 includes a plurality of key switches, and outputs a command representing the contents of operations by the operator to these key switches to the CPU 106.

  The touch panel 103 includes, for example, a display device such as an LCD (liquid crystal display) and a transparent two-dimensional touch sensor arranged on the display screen of the display device. The touch panel 103 displays an arbitrary image on the display device under the control of the CPU 106. The touch panel 103 detects an operator's touch position on the display screen of the display device with a two-dimensional touch sensor and outputs coordinate data representing the touch position. The touch panel 103 is used to display images representing various types of information to be presented to the operator and to input operator operations.

  The customer display 104 displays an arbitrary character string or image under the control of the CPU 106. The customer display 104 is used to display various character strings and images to be presented to the customer. As the customer display 104, for example, a fluorescent tube display or an LCD can be used.

  The CPU 106 corresponds to the central part of the computer. The CPU 106 controls each element of the product recognition apparatus 100 to realize various operations as the product recognition apparatus 100 based on the operating system, middleware, and application program stored in the ROM 107 and the RAM 108.

  The ROM 107 corresponds to the main storage portion of the computer. The ROM 107 stores the above operating system. The ROM 107 may store the above middleware and application programs. The ROM 107 may store data that is referred to when the CPU 106 performs various processes.

  A RAM 107 corresponds to a main storage portion of the computer. The RAM 108 stores data referred to when the CPU 106 performs various processes. Further, the RAM 108 is used as a so-called work area for storing data temporarily used when the CPU 106 performs various processes.

  The application program stored in the ROM 107 includes a program described regarding recognition processing for recognizing a product by object recognition based on image data generated by the imaging device 105d.

  The keyboard interface 109, the panel interface 110, the display interface 111, the imaging interface 112, and the POS terminal interface 114 transfer data between the CPU 106, the keyboard 102, the touch panel 103, the customer display 104, the imaging device 105d, and the POS terminal 200, respectively. Mediate.

  The drive unit 113 drives the light emitting devices 105e and 105f to light up under the control of the CPU 106, respectively.

  The POS terminal 200 has a function of communicating with the server 700 via the communication network 600.

  Next, the operation of the product recognition apparatus 100 will be described.

  When the merchandise recognition apparatus 100 is in an operation state in which merchandise recognition is to be performed, the CPU 106 operates the imaging device 105d so that imaging is performed at a constant frame rate, and the merchandise is received at an appropriate timing synchronized with this. The light emitting devices 105e and 105f are caused to emit light so that they are illuminated.

  An optical image of a product that is lit in front of the reading window 101a and is illuminated by light emitted from the light emitting devices 105e and 105f enters the lens system of the imaging device 105d through the opening OP3 of the reading window 101a and the light shielding plate 105g. Then, an image is formed on the image sensor of the imaging device 105d. The image sensor generates image data corresponding to the formed optical image. The CPU 101a captures the image data generated by the image sensor in the RAM 108, compares the image data with the comparison data stored in the dictionary, and executes recognition processing for recognizing the object. Recognize a product that has been trapped in front of the reading window 101a. Therefore, the CPU 106 functions as a recognition unit. The matching data is a feature amount or a reference image, and these matching data are stored in the dictionary in advance. The feature amount is a parameterization of appearance features such as the standard shape, surface color, pattern, and unevenness of the product. The dictionary is provided in any of the product recognition device 100, the POS terminal 200, and a server (not shown) connected to the POS terminal 200.

  The recognition process may be the same as the process performed in an existing similar device. Note that recognizing an object included in an image is called generic object recognition. Regarding such general object recognition, various recognition techniques are described in the following documents.

Keiji Yanai, “Current Status and Future of General Object Recognition”, IPSJ Journal, Vol. 48, no. SIG16 [Search August 10, 2010], Internet <URL: http://mm.cs.uec.ac.jp/IPSJ-TCVIM-Yanai.pdf>
Further, techniques for performing general object recognition by dividing an image into regions for each object are described in the following documents.

Jamie Shotton et al., “Semantic Texton Forests for Image Categorization and Segmentation”, [searched August 10, 2010], Internet <URL: http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1. 1.145.3036 & rep = rep1 & type = pdf>
Now, most of the light emitted from the light emitting devices 105e and 105f is radiated to the outside of the housing 105a through the reading window 101a, but a part of the light is reflected by the housing 105a and then passes through various paths. There is a possibility that the imaging device 105d may be reached through. In addition to the direct path described above, light from the product may be reflected by the housing 105a and then reach the imaging device 105d through various paths.

  However, the reflected light that has reached the substrate 105a is substantially not reflected by the substrate 105a and attenuates significantly. Of the reflected light, the light that reaches the light shielding region of the light shielding plate 105g is attenuated substantially without being transmitted or reflected by the light shielding plate 105g.

  In this way, much of the reflected light does not enter the imaging device 105d. That is, the amount of light incident on the imaging device 105d after being reflected by the casing 105a is reduced by the substrate 105b and the light shielding plate 105g, thereby reducing unnecessary reflection and improving the image quality of the product. It becomes possible.

  And the recognition process with respect to the image of a high quality product enables highly accurate product recognition.

  This embodiment can be modified as follows.

  Instead of the light shielding plate 105g, a plurality of light shielding plates each having a different light shielding region may be provided.

  Instead of the light shielding plate 105g, a non-plate light shielding member may be provided.

  In the case where a substrate having a surface exposed to the internal space of the housing 105a is provided in addition to the substrate 105b, antireflection processing may be performed on the substrate other than the substrate 105b in the same manner as the substrate 105b. For example, if the substrate 105c is arranged so as to be exposed in the internal space of the housing 105a, the surface of the substrate 105c facing the reading window 101a may be subjected to antireflection processing. In this case, the substrate 105c corresponds to the second substrate.

Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.
The invention described in the scope of the original claims of the present application will be added below.
[Appendix 1] A housing having an imaging window formed on one surface;
A substrate that is disposed inside the housing and on which a treatment for preventing reflection of light is applied to at least a part of a surface facing the imaging window;
A light-emitting device attached to the substrate and emitting illumination light through the imaging window to the outside of the housing;
An imaging device that images the object illuminated by the illumination light through the imaging window;
A light-shielding member provided inside the housing, which blocks the imaging and prevents at least a part of reflected light from entering the imaging device at various locations inside the housing. An imaging device.
[Supplementary Note 2] The imaging apparatus according to Supplementary Note 1, wherein the light shielding member is a transparent plate member that is partially subjected to a process of shielding the reflected light toward the imaging device.
[Supplementary Note 3] The supplementary note 1 or 2, wherein the substrate is subjected to a treatment for preventing reflection of light on the silk character, with respect to at least a part of the silk character formed on the substrate. Imaging device.
[Supplementary Note 4] A second substrate, which is different from the substrate, is disposed inside the housing, and has a treatment for preventing reflection of light on at least a part of a surface facing the imaging window;
The apparatus according to any one of appendix 1-3, further comprising: a second light emitting device attached to the second substrate and emitting illumination light to the outside of the housing through the imaging window. The imaging device described.
[Supplementary Note 5] A housing having an imaging window formed on one surface;
A substrate that is disposed inside the housing and on which a treatment for preventing reflection of light is applied to at least a part of a surface facing the imaging window;
An issuing device attached to the substrate and emitting illumination light to the outside of the housing through the imaging window;
An imaging device that images the object illuminated by the illumination light through the imaging window;
Recognizing means for recognizing the object based on characteristics of the object appearing in an image obtained by the imaging device;
A light-shielding member provided inside the housing, which blocks the imaging and prevents at least a part of reflected light from entering the imaging device at various locations inside the housing. An object recognition scanner.

  DESCRIPTION OF SYMBOLS 100 ... Product recognition apparatus, 101a ... Reading window, 105 ... Imaging part, 105a ... Case, 105b, 105c ... Substrate, 105d ... Imaging device, 105e, 105f ... Light emitting device, 105g ... Light-shielding plate, 200 ... POS terminal, OP1 , OP2, OP3 ... opening.

Claims (5)

A housing with an imaging window on one side;
A substrate that is disposed inside the housing and on which a treatment for preventing reflection of light is applied to at least a part of a surface facing the imaging window;
A light-emitting device attached to the substrate and emitting illumination light through the imaging window to the outside of the housing;
An imaging device that images the object illuminated by the illumination light through the imaging window;
A light shielding member that is provided inside the housing and that blocks at least part of reflected light from various locations inside the housing from entering the imaging device without passing through the imaging window. An image pickup apparatus comprising:   The imaging apparatus according to claim 1, wherein the light shielding member is a transparent plate member that is subjected to a process for shielding a reflected light toward the imaging device in a partial area.   The imaging device according to claim 1, wherein the substrate is subjected to a treatment for preventing reflection of light from the silk character on at least a part of the silk character formed on the substrate. A second substrate that is different from the substrate, disposed inside the housing, and subjected to a treatment for preventing reflection of light on at least a part of a surface facing the imaging window;
4. The apparatus according to claim 1, further comprising a second light emitting device attached to the second substrate and emitting illumination light to the outside of the housing through the imaging window. The imaging device described in 1. A housing with an imaging window on one side;
A substrate that is disposed inside the housing and on which a treatment for preventing reflection of light is applied to at least a part of a surface facing the imaging window;
A light-emitting device attached to the substrate and emitting illumination light through the imaging window to the outside of the housing;
An imaging device that images the object illuminated by the illumination light through the imaging window;
Recognizing means for recognizing the object based on characteristics of the object appearing in an image obtained by the imaging device;
A light shielding member that is provided inside the housing and that blocks at least part of reflected light from various locations inside the housing from entering the imaging device without passing through the imaging window. An object recognition scanner characterized by comprising: