reading device

Abstract

A reading device for obtaining information of a specified product, the reading device of the embodiment includes a housing, an imaging section, and an illumination section. The housing includes a transparent reading window. The imaging section is built into the housing and images an image across the reading window. The illumination section illuminates an imaging object of the imaging section by surface emission toward the outside of the housing, is disposed outside the edge of the reading window, and is inclined to the reading window in a manner that protrudes from the reading window more on a side farther from the reading window.

Description

[0001] This application is an application that entered the Chinese national phase of international application PCT / JP2021 / 029304 (international application date: August 6, 2021), and is cited in this specification by reference to the aforementioned international application. Furthermore, this application is based on Japanese patent application JP2020-160591 (application date: September 25, 2020) and claims priority to that application. The entire contents of that application are incorporated herein by reference. Technical Field

[0002] Embodiments of the present invention relate to a reading device. Background Technology

[0003] Currently, sales data processing devices such as POS (Point of Sales) terminals are equipped with reading devices that acquire images of barcodes or QR codes, as well as images of the product's appearance, as information for specifying the product. The reading device has a built-in camera unit consisting of an image sensor, and a transparent reading window, located through a portion of the housing, captures images of the barcode and the product's surface.

[0004] The aforementioned existing reading devices include a light source (such as an LED) within the housing to illuminate the surface of the code image or product being read during image capture. However, when the light source within the housing illuminates the object through the reading window, light reflected from the inner surface of the reading window may enter the captured image. In this case, reading performance degrades, which is inconvenient. Summary of the Invention

[0005] The problem this invention aims to solve is to eliminate the reflection of light into the inside of the reading window, thereby improving the reading performance of the reading device.

[0006] The reading device of this embodiment is for obtaining information about a specified product, and includes a housing, a camera unit, and an illumination unit. The housing has a transparent reading window. The camera unit is built into the housing and captures an image through the reading window. The illumination unit illuminates the object being captured by the camera unit by emitting surface light toward the outside of the housing; it is positioned on the outer edge of the reading window and is tilted toward the reading window such that the further away from the reading window it protrudes from the reading window, the more it protrudes from the reading window. Attached Figure Description

[0007] Figure 1 This is a perspective view showing the appearance of the reading device in the embodiment.

[0008] Figure 2 This is the front view of the reading device.

[0009] Figure 3 It is a cross-sectional view showing the range of light reaching the upper and lower emitting surfaces of the reading window.

[0010] Figure 4 It is a cross-sectional view showing the range of light reaching the left and right emitting surfaces of the reading window.

[0011] Figure 5 It is a cross-sectional view showing the state of the product near the reading window.

[0012] Figure 6 It is an exploded three-dimensional diagram showing the composition of the area surrounding the cover.

[0013] Figure 7 This is a front view illustrating the positional relationship between the LED components and the light guide plate.

[0014] Figure 8 This is a cross-sectional diagram illustrating the positional relationship between the LED components, the light guide plate, and the diffuser plate. Detailed Implementation

[0015] (First Embodiment)

[0016] The embodiments are described with reference to the accompanying drawings. Figure 1 This is a perspective view showing the appearance of the reading device 1 in the embodiment. Figure 2 This is a front view of the reading device 1. It should be noted that, for ease of explanation, an orthogonal coordinate system consisting of the X, Y, and Z axes is added to the accompanying drawing. In the figure, the direction indicated by the arrow is the positive direction, and the opposite direction is the negative direction. The X-axis direction is the width direction of the reading device 1. The Y-axis direction is the depth direction of the reading device 1. The Z-axis direction is the height direction of the reading device 1. The user (operator) of the device stands at the front side in the figure.

[0017] The reading device 1 is a device for obtaining information about a specified product. The information about the specified product may be, for example, a product code. The reading device 1 reads the information from an image captured by the camera, which shows the product code as a barcode or similar code. The reading device 1 includes a camera unit 10 (see reference 10). Figure 3 and Figure 4 ), housing 20 and lighting unit 30, etc.

[0018] The housing 20 has a main body 21 and a cover 22. The main body 21 is a container with an opening on one side, and a camera unit 10 is built into it. The cover 22 is a component that blocks the opening of the main body 21, and it has a transparent reading window 40 in the center. That is, the reading window 40 is provided on the front of the reading device 1. The camera unit 10 has an image sensor such as a CCD (Charge Coupled Device) or a CMOS (Complementary MOS) and is built into the housing 20 to capture images through the reading window 40.

[0019] The illumination unit 30 consists of four light-emitting surfaces 31 to 34. The light-emitting surfaces 31 to 34 are held by the cover portion 22 and are positioned at four locations on the outer side of the edge of the reading window 40. Light-emitting surfaces 31 and 32 are positioned to sandwich the reading window 40 from the left and right sides. Light-emitting surfaces 33 and 34 are positioned to sandwich the reading window 40 from the top and bottom.

[0020] The light-emitting surfaces 31-34 illuminate the image captured by the camera unit 10 by emitting light towards the outer side of the housing 20. The light-emitting surfaces 31-34 are angled towards the reading window 40 such that they protrude further from the reading window 40 the further away from it. Thus, the light-emitting surfaces 31-34 illuminate the oblique front of the reading window 40. The surface directions (directions of the surface normals) of the light-emitting surfaces 31-34 are different. The surface directions of each light-emitting surface 31-34 intersect on the front side of the reading window 40.

[0021] Figure 3 This diagram shows the reach of light from the upper and lower luminous surfaces 33 and 34 of the reading window 40. Figure 2 A cross-sectional view of the location indicated by line AA. Figure 4 This diagram represents the light reach range of the left and right emitting surfaces 31 and 33 of the reading window 40. Figure 2 The cross-sectional views are shown in the diagrams, with the BB line indicating the location. In each view, the area reached by the light is illustrated by dots enclosed by triangles. Light-emitting surfaces 33 and 34 are distant illumination units, illuminating the area far from the reading window 40. Light-emitting surfaces 31 and 33 are nearby illumination units, illuminating the vicinity of the reading window 40. The differences in the reach (illumination range) of each light source correspond, for example, to the differences in the tilt angles relative to the reading window 40. When comparing the tilt angle α of the light-emitting surfaces 33 and 34 relative to the reading window 40 with the tilt angle β of the light-emitting surfaces 31 and 33 relative to the reading window 40, angle α is set to be smaller than angle β.

[0022] The intensity of the light emitted by the light-emitting surface 31 is equal to the intensity of the light emitted by the light-emitting surface 32. The intensity of the light emitted by the light-emitting surface 33 is stronger than the intensity of the light emitted by the light-emitting surfaces 31 and 32 because the light-emitting surface 33 illuminates distant objects. Since the light-emitting surface 34 emits light upwards, a strong light intensity may cause glare to the user; therefore, it is preferable to set this intensity according to the settings of the reading device 1. Thus, the intensity of the light emitted by the light-emitting surface 34 can also be set to be the same as or weaker than the intensity of the light emitted by the light-emitting surfaces 31 and 32.

[0023] Figure 5 This is a cross-sectional view showing the product P approaching the reading window 40. Light is emitted from nearby illumination units (light-emitting surfaces 31, 32) to illuminate the product located near the reading window 40.

[0024] When the product is near the reading window 40, a shadow is formed where light cannot reach the product. When the camera unit 10 takes a picture in this state, the shadow becomes stronger or uneven in the captured image. Therefore, the product near the reading window 40 is illuminated from the left and right by the light-emitting surfaces 31 and 32 that emit light of equal intensity.

[0025] In addition, as Figure 5 As shown, the light-emitting surfaces 31-34 are inclined relative to the reading window 40, and the side further away from the reading window 40 protrudes more from it. Therefore, even if the product P approaches the reading window 40 more than necessary, the product P is more likely to come into contact with the outer periphery 221 of the cover 22 that holds the light-emitting surfaces 31-34 than with the reading window 40. Based on this positional relationship and shape characteristics, the reading window 40 is in a state that is not easily damaged or soiled.

[0026] Next, the structure and arrangement of the light-emitting surfaces 31 to 34 of the lighting unit 30 will be explained. Figure 6 This is an exploded perspective view showing the structure around the cover 22. The front part of the housing 20 includes the cover 22, which is the opening of the main body 21, and the LED substrate (light-emitting part) 51, light guide plate (light guide part) 52, and diffuser plate (diffuser part) 53 constituting the lighting part 30. The light guide plate 52 collects light from the edge (end face) and emits light from the surface. The diffuser plate 53 diffuses the light collected from one side and emits it from the other side.

[0027] In this embodiment, the LED substrate 51 includes four LED substrates 511 to 514. Each LED substrate 511 to 514 has multiple LED elements 515 mounted on it (see reference). Figure 7 The substrate is a light guide plate. Furthermore, in this embodiment, four light guide plates 521 to 524 are provided as the light guide plate 52. Also, in this embodiment, four diffuser plates 531 to 534 are provided as the diffuser plate 53.

[0028] The light-emitting surface 31 of the lighting unit 30 is formed by stacking an LED substrate 511, a light guide plate 521, and a diffuser plate 531. Similarly, the light-emitting surface 32 is formed by stacking an LED substrate 512, a light guide plate 522, and a diffuser plate 532, the light-emitting surface 33 is formed by stacking an LED substrate 513, a light guide plate 523, and a diffuser plate 533, and the light-emitting surface 34 is formed by stacking an LED substrate 514, a light guide plate 524, and a diffuser plate 534.

[0029] The stacking order from the innermost layer is as follows: LED substrate 51, light guide plate 52, cover 22, and diffuser plate 53. The diffuser plate 53 faces the light guide plate 52 through the opening 222 of the cover 22.

[0030] Figure 7 This is a front view illustrating the positional relationship between LED element 515 and light guide plate 523. Light guide plate 523 receives light emitted from LED element 515 from its edge (end face) and then emits light from the surface. It should be noted that the positional relationships of other light guide plates 521, 522, 524 and the LED elements 515 on other LED substrates 511, 512, 514 are also related... Figure 7 The same applies to the light guide plate 523.

[0031] Figure 8 This is a cross-sectional view illustrating the positional relationship between the LED element 515, the light guide plate 521, and the diffuser plate 531. In this figure, the symbol Q represents the light-emitting path based on the light guide plate 521, and the symbol R represents the diffused light path based on the diffuser plate 531.

[0032] The diffuser plate 531, facing the light guide plate 521 across the opening 222 of the cover portion 22, causes light emitted from the surface of the light guide plate 521 to be collected from the inner surface and diffused before being emitted from the outer surface. It should be noted that the positional relationships between the other diffuser plates 532-534, the light guide plates 522-524, and the LED element 515 are also... Figure 8 The same applies to the diffuser plate 531 and the light guide plate 521.

[0033] It should be noted that the reading device 1 includes a control unit and a memory unit. The memory unit is composed of storage devices such as SSD (Solid State Memory) and flash memory. The memory unit stores control programs, product ledgers, camera settings, etc.

[0034] The control unit is a computer equipped with a CPU (Central Processing Unit), ROM (Read Only Memory), and RAM (Random Access Memory). The CPU controls the overall operation of the reading device 1. The ROM stores various programs and data, such as the program that drives the CPU. The RAM stores barcodes and other data read from images captured by the camera unit 10. Furthermore, the RAM is used as the CPU's working area to expand the various programs and data stored in the ROM and memory units. The control unit executes various control processes of the reading device 1 by operating the CPU according to the control programs stored in the ROM, memory units, and RAM.

[0035] Based on the above configuration, the reading device 1 illuminates the surface of the product that the user is pointing at the reading window 40 through the illumination unit 30, and captures an image of the product's surface illuminated by the illumination unit 30 through the imaging unit 10. Furthermore, after obtaining a code image or a feature quantity of the product's appearance from the captured image output by the imaging unit 10, the reading device 1 identifies the product by querying a predefined database for information obtained after decoding the code image or information associated with the feature quantity.

[0036] It should be noted that the reading device 1 can also output camera images, and the data will be processed by the sales data processing device such as the POS terminal after the code image and feature quantity are extracted from the camera image.

[0037] In the operation of the reading device 1 described above, the illumination unit 30 includes a nearby illumination unit (light-emitting surfaces 31, 32) that illuminates the vicinity of the reading window 40, and a distant illumination unit (light-emitting surfaces 33, 34) that primarily illuminates a range slightly farther away from the reading window 40. Thus, the reading device 1 can illuminate the product over a wide range, from the vicinity of the reading window 40 to its distance.

[0038] In addition, the surrounding lighting unit illuminates the product from the left and right sides, so even in the vicinity of the reading window 40 where shadows are strong or uneven, the camera can obtain a sufficient image of the specified product and achieve suitable reading performance.

[0039] It should be noted that, in this embodiment, although a light-emitting surface 34 for illumination from below is also provided as a distant illumination unit, in practice, only the light-emitting surface 33 on the upper side may be provided.

[0040] While several embodiments of the present invention have been described above, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are all included in the scope and spirit of the invention, and are included within the scope of the invention as described in the claims and their equivalents.

Claims

1. A reading device for obtaining information about a specified product, comprising: The casing has a transparent reading window on the front; A camera unit, built into the housing, captures images through the reading window; and The illumination unit illuminates the object being photographed by the camera unit located in front of the housing by emitting light from a surface toward the outer side of the housing. The illumination unit is positioned on the outer edge of the reading window, and is tilted toward the reading window such that it protrudes further from the reading window the further away from it. in, The illumination unit includes a nearby illumination unit that illuminates the vicinity of the reading window at a large tilt angle relative to the reading window, and a distant illumination unit that illuminates a range far from the reading window at a small tilt angle relative to the reading window. The nearby lighting units are arranged on the left and right sides of the reading window. The distant illumination unit is positioned above the reading window.

2. The reading device according to claim 1, wherein, The distance illumination unit is also located at the bottom of the reading window.

3. The reading device according to claim 1 or 2, wherein, The illumination unit includes a light-emitting part that emits light, a light guide part that receives light from the light-emitting part from the edge and emits light, and a diffuser plate that is stacked on the light guide part and diffuses the light emitted from the light guide part.

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