containment unit

Abstract

To provide a container that can smoothly advance circulation type recycling and reduce a reading error of an identification code, and is suitable for retail sale.SOLUTION: The present invention relates to a container that has a container body and a cap for sealing a contained object in the container body, wherein the cap has an identification code on its top surface, the container body includes a plurality of recessed parts and has an image whose area is larger than the identification code, and a difference in a diffuse reflectance between a display part and a non-display part of the identification code is larger than a difference in a diffuse reflectance between a portion of the image and a non-image portion.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a container and a container body. [Background technology]

[0002] Conventionally, containers such as PET (Poly Ethylene Terephthalate) bottles have been known that have labels affixed to them indicating the name, ingredients, expiration date, barcode, QR code (registered trademark), recycle mark, logo mark, etc. Also, attempts have been made to display designs or pictures that appeal to consumers on the labels in order to demonstrate the individuality of products or to increase their competitiveness.

[0003] Meanwhile, marine pollution caused by plastic waste has been a hot topic in recent years, and efforts to eliminate pollution from plastic waste are gaining momentum worldwide, leading to an increased demand for closed-loop recycling of containers. Here, closed-loop recycling of containers refers to recycling companies turning used containers that have been separated and collected into flakes that can be used as the raw material for containers, and then manufacturing containers again. In order to smoothly carry out this type of circular recycling, it is preferable to thoroughly separate and collect waste by material, such as containers or labels, but the task of removing labels from containers for separate collection is time-consuming, and is one of the constraints to thorough separate collection.

[0004] In relation to this, a technology is already known that provides a container body without a label by directly forming a pattern displaying information such as the name and ingredients on the surface of the container body with laser light. For example, a container has been proposed in which a visible area is formed by an aggregate of microstructures, and information such as numbers, symbols, and images can be viewed through this visible area, with the aim of improving the visibility of directly recorded information, enabling direct recording of large amounts of information such as images, and directly recording at high speeds that are suitable for commercialization (see, for example, Patent Document 1). Summary of the Invention [Problem to be solved by the invention]

[0005] The above-mentioned Patent Document 1 describes an example in which a one-dimensional barcode is provided on the top surface of a beverage bottle cap by irradiating a processed laser beam. However, since the one-dimensional barcode in Patent Document 1 is simply drawn directly with a laser beam, there is a problem in that the difference in diffuse reflectance (contrast) between the display and non-display parts of the barcode is insufficient, resulting in a reading error.

[0006] An object of the present invention is to provide a container which enables smooth circulation recycling, reduces reading errors of identification codes, and is suitable for retail sale. [Means for solving the problem]

[0007] The container of the present invention, as a means for solving the above problem, is a container having a container body and a cap that seals the contents within the container body, wherein the container body has an identification code on the upper surface of the cap, the container body includes a plurality of recesses and has an image having a larger area than the identification code, and the difference in diffuse reflectance between the display portion and the non-display portion of the identification code is greater than the difference in diffuse reflectance between the image portion and the non-image portion. Effect of the Invention

[0008] According to the present invention, it is possible to smoothly promote closed-loop recycling, reduce errors in reading identification codes, and provide a container suitable for retail sale. [Brief description of the drawings]

[0009] [Figure 1A] FIG. 1A is a schematic diagram showing the state of diffuse reflection of light on the surface of a container body before laser processing. [Figure 1B] FIG. 1B is a schematic diagram showing the state of diffuse reflection of light on the surface of a container body on which a plurality of recesses are formed by laser processing. [Figure 1C]FIG. 1C is a schematic diagram showing the surface of a container body on which a plurality of recesses have been formed by laser processing, and the state of diffuse reflection of light from the contents. [Figure 1D] FIG. 1D is a diagram showing an example of a one-dimensional barcode as an identification code formed on the upper surface of the cap. [Diagram 2] FIG. 2 is a diagram showing an example of an image drawn on a container body having an area larger than that of the identification code on the top surface of the cap. [Diagram 3] FIG. 3 is a diagram showing another example of an image drawn on a container body having an area larger than that of the identification code on the top surface of the cap. [Figure 4A] FIG. 4A is a diagram showing an example of a method for photographing a container body. [Figure 4B] FIG. 4B is a diagram showing a state in which a white diffusion surface is placed on the side surface of the container body in the method of photographing the container body. [Diagram 5] FIG. 5 is a schematic diagram showing an image X of a container body and a portion Y other than the image when photographing the container body. [Figure 6] FIG. 6 is a graph showing the relationship between the G signal and the brightness. [Figure 7] FIG. 7 is a graph showing the relationship between image lightness (L*0) and subjective evaluation score. [Figure 8] FIG. 8 is a graph showing the relationship between the difference (ΔL*) between the brightness of the image and the brightness of the portion other than the image, and the subjective evaluation score. [Figure 9] FIG. 9 is a graph showing the relationship between x and Y in the formula: Y=1-exp(-x). [Figure 10] FIG. 10 is a graph showing the relationship between the subjective evaluation score and the visibility value. [Figure 11] FIG. 11 is a graph showing the relationship between the visibility value of a barcode written with a laser on a container body and the reading success rate. [Figure 12] FIG. 12 is a graph showing the relationship between the symbol contrast of the barcode on the cap and the reading success rate. [Figure 13] FIG. 13 is a graph showing the relationship between the visibility value and the evaluation rank. [Figure 14]FIG. 14 is a graph showing the relationship between the processing ratio and the visibility value. [Figure 15A] FIG. 15A is a diagram showing an example of an image including multiple recessed and non-recessed portions. [Figure 15B] FIG. 15B is a diagram showing another example of an image including a plurality of recessed portions and non-recessed portions. [Figure 15C] FIG. 15C is a diagram showing another example of an image including a plurality of recessed portions and non-recessed portions. [Figure 15D] FIG. 15D is a diagram showing another example of an image including a plurality of recessed and non-recessed portions. [Figure 15E] FIG. 15E is a diagram showing another example of an image including a plurality of recessed and non-recessed portions. [Figure 15F] FIG. 15F is a diagram showing another example of an image including a plurality of recessed and non-recessed portions. [Figure 16A] FIG. 16A is a diagram showing an example in which the size of the processed portion constituting the recess is equal to or smaller than one dot width, which is the resolution. [Figure 16B] FIG. 16B is a diagram showing another example in which the size of the processed portion constituting the recess is equal to or smaller than one dot width which is the resolution. [Figure 16C] FIG. 16C is a diagram showing another example in which the size of the processed portion constituting the recess is equal to or smaller than one dot width which is the resolution. [Figure 17] FIG. 17 is a schematic diagram showing an example of a one-dimensional barcode. [Figure 18] FIG. 18 is a diagram illustrating bars and spaces in a one-dimensional barcode. [Figure 19] FIG. 19 is a diagram showing the positional relationship between the one-dimensional barcode provided on the top surface of the cap and the image provided on the container body. [Figure 20A] FIG. 20A is a diagram showing a case where a barcode is provided on the top surface of a cap of a normal plastic bottle. [Figure 20B] FIG. 20B is a diagram in which the longitudinal length of the bar of the one-dimensional barcode provided on the upper surface of the cap is different between the center and the ends in the lateral direction of the bar of the one-dimensional barcode. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] (Container) The container of the present invention has a container body and a cap that seals the contents within the container body, the cap has an identification code on the upper surface of the cap, the container body includes a plurality of recesses and has an image with a larger area than the identification code, and the difference in diffuse reflectance between the display portion and the non-display portion of the identification code is greater than the difference in diffuse reflectance between the image portion and the non-image portion.

[0011] In the conventional technology, even if a barcode can be drawn on a beverage bottle using a laser beam, the visibility of the barcode changes depending on the color and absorbency of the liquid contained therein, resulting in frequent failures in reading the barcode. Furthermore, if writing barcodes on beverage bottles is no longer an option and barcodes are instead placed on the top surface of the cap, the size of the barcode becomes very small. In that case, it has been found that if the contrast of the barcode is not high, similarly frequent failures in reading will occur. In other words, it is desirable to provide a container that provides the necessary contrast depending on the combination of the cap color and the barcode color when a barcode is placed on the top surface of the cap, by establishing an evaluation and judgment criterion for whether or not a barcode written with a laser can be stably read by the liquid contained inside the beverage bottle.

[0012] First, we will explain the image including multiple recesses formed on the container body. When an image consisting of multiple recesses is formed on the surface of the container body by laser processing or the like and they are assembled, the diffuse reflectance on the surface becomes larger than before processing (Fig. 1A), and a visible area becomes cloudy (Fig. 1B). The difference in diffuse reflectance (contrast) between the image and non-image parts is called "Cbottle." The difference in diffuse reflectance between the image and non-image parts makes it possible to visually recognize processed images such as characters without using ink, etc. Note that by using the bar portion of the one-dimensional barcode as the processing portion (Fig. 1B) and the space portion as the non-processing portion (Fig. 1A) as the identification code on the container body, it is also possible to form a barcode with reversed light and dark compared to printing on paper with ink (the bar portion is bright and the container body is dark). In this case, the contrast is the difference between the high diffuse reflectance (bar portion) and the low diffuse reflectance (container body), and the value of the contrast is always positive. Also, in this specification, although the image portion by surface laser processing etc. is described as a plurality of recesses, it goes without saying that it has an uneven shape when viewed microscopically.

[0013] In the present invention, a one-dimensional barcode 2 as an identification code is provided on the upper surface of the cap 8 of the container as shown in Fig. 1D, and the container body surface has an image larger in area than the identification code including a plurality of recesses by laser processing or the like. The difference in diffuse reflectance between the display portion and the non-display portion of the identification code is larger than the difference in diffuse reflectance between the image portion and the non-image portion. That is, when the difference in diffuse reflectance (contrast) between the display portion and the non-display portion of the identification code on the cap of the container is "Ccap", it is characterized by satisfying the following formula, Cbottle < Ccap. By satisfying Cbottle < Ccap, a reliable identification code without reading errors can be provided for the container. The difference in diffuse reflectance between the display portion and the non-display portion of the identification code represented as Ccap is called symbol contrast and is represented by the following formula (2). In the case of a barcode with reversed light and dark compared to printing on paper with ink (the bar portion is bright and the container body is dark), if there is no absolute value in formula (2), it will be a negative value. Therefore, an absolute value is attached so that the value is positive as in the case of contrast. Symbol contrast = |Diffuse reflectance of the non-display portion of the identification code - Diffuse reflectance of the display portion of the identification code| ··· Formula (2) The display portion of an identification code refers to the bars in a barcode, and the non-display portion of an identification code refers to the background between the bars of the barcode. For example, if a white background is printed on a green material and a black barcode is printed on top of that, the black portion is the display portion and the white portion is the non-display portion.

[0014] Here, the diffuse reflectance can be measured using an integrating sphere spectrophotometer such as the X-Rite cix6 series. An integrating sphere spectrophotometer can measure only the diffuse reflectance without including specular reflected light. In particular, in the case of transparent resin, the sample is placed on a light trap to prevent the transmitted light from returning from the light trap so that the light transmitted through the sample is not reflected at another location and included in the measured value, and the diffuse reflectance of the surface is measured.

[0015] The identification code on the top surface of the cap may be printed with ink or may be laser processed. Also, as shown in FIG. 1D, the identification code area of ​​the cap may be printed with a white base and the bar portion printed thereon, or the bar portion may be printed directly on the cap. Note that if the cap is a dark color, printing the bar portion in black reduces the contrast of the identification code, so it is preferable to print a base color separately in the identification code area. Also, the cap may be printed in advance, or may be printed on demand when the content (such as a beverage) is filled into the container. However, when placing a barcode on the top surface of the cap as an identification code, the barcode will be very small. If the contrast of a small barcode is not sufficient, there will be many reading errors. For this reason, a standard is required to evaluate and judge the symbol contrast of the small barcode on the top surface of the cap.

[0016] The container of the present invention has a container body and a cap that seals the contents within the container body.

[0017] <Container body> The container body is not particularly limited in terms of material, shape, size, structure, color, etc., and can be appropriately selected depending on the purpose. The material of the container body is not particularly limited and can be appropriately selected depending on the purpose. Examples of the material include resin and glass. Examples of resins for the container body include polyvinyl alcohol (PVA), polybutylene adipate / terephthalate (PBAT), polyethylene terephthalate succinate, polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET), polyvinyl chloride (PVC), polystyrene (PS), polyurethane, epoxy, bio-polybutylene succinate (PBS), polylactic acid blend (PBAT), starch blend polyester resin, polybutylene terephthalate succinate, polylactic acid (PLA), polyhydroxybutyrate / hydroxyhexanoate (PHBH), polyhydroxyalkanoic acid (PHA), bio-PET30, bio-polyamide (PA) 610, 410, 510, bio-PA1012, 10T, bio-PA11T, MXD10, bio-polycarbonate, bio-polyurethane, bio-PE, bio-PET100, bio-PA11, bio-PA1010, and the like. These may be used alone or in combination of two or more. Among these, biodegradable resins such as polyvinyl alcohol, polybutylene adipate / terephthalate, and polyethylene terephthalate succinate are preferred from the viewpoint of environmental load.

[0018] The shape of the container body is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include a bottle shape, a cylindrical shape, a square prism shape, a box shape, a cone shape, etc. Among these, the bottle shape is preferable. The bottle-shaped container body has a mouth, a shoulder connected to the mouth, a body connected to the shoulder, and a bottom connected to the body. The size of the container body is not particularly limited and can be appropriately selected depending on the application of the container. The structure of the container body is not particularly limited and can be appropriately selected depending on the purpose. For example, it may be a single-layer structure or a multi-layer structure.

[0019] Examples of the color of the container body include colorless and transparent, colored and transparent, colored and opaque, etc. Among these container body colors, particularly colorless and transparent ones have poor visibility of the image written by the laser, which causes a problem that the barcode written on the container body in that case cannot be read, and therefore the present invention is necessary.

[0020] <statue> The surface of the container body includes a plurality of recesses, and an image is formed that is larger in area than the identification code on the top surface of the cap. Since the image has non-recesses where no recesses are formed, it is not necessary to irradiate the entire image with a laser. Therefore, productivity is significantly improved by the proportion of the non-recessed area. However, as the proportion of the non-recessed area increases, the visibility value deteriorates, so conditions should be set for the proportion of the non-recessed area.

[0021] The image includes, for example, letters, symbols, figures, pictures, codes, etc., and specifically means information such as the name, ingredients, identification number, manufacturer name, manufacturing date and time, expiration date, identification code (bar code, two-dimensional code), recycling mark, or logo mark. Among the above images, identification codes are important information. When managing things such as products, business locations and departments, and assets, a "code" that is assigned an identifying number or symbol is required, and a code for identifying things is generally called an "identification code." Identification codes include "product identification codes" such as JAN codes. JAN codes are used to manage which product has been purchased at the register when it is purchased, and are international product identification numbers that pinpoint "which business the product is from." They are usually used as barcodes displayed on products or packaging. Another type of identification code is a two-dimensional code that can store a lot of information, and the most well-known two-dimensional code is the QR code (registered trademark). As two-dimensional codes have the same effect, this specification will use a barcode, which is a representative type of identification code, as an example.

[0022] The recess is formed by a plurality of processed parts, which are arranged along the first scanning direction (main scanning direction) and may be dot-shaped or line-shaped. It is preferable that the processed parts are circular or elliptical in plan view. In terms of visibility and productivity, it is preferable that the recesses are arranged linearly along the first scanning direction with a plurality of processed parts in contact or overlapping with each other. In addition, since the image drawn on the container body is intended to serve as a substitute for a label, the size of the image must be drawn in an area larger than the area of ​​the barcode on the cap, and the invention is one in which the image including the drawn characters and pictures is clearly recognized in that area. The area described here is the area of ​​that area, and in the case of a barcode, it is within the dotted line in Figure 2, and the area of ​​the image drawn on the container body with the laser light is roughly calculated as within the dotted line in Figure 3, and is the sum of the areas of these images for the entire bottle.

[0023] By non-recessed is meant a flat area of ​​the container body that does not have any recesses formed therein. There are two scanning directions of the laser light, a main scanning direction and a sub-scanning direction, which are perpendicular to each other. The main scanning direction is the direction in which the laser irradiation means moves, and the sub-scanning direction is the direction in which the container body, which is the object of laser processing, moves. The first scanning direction is the main scanning direction in the laser processing, and the second scanning direction is the sub-scanning direction in the laser processing.

[0024] Here, as shown in Fig. 1B, when multiple recesses 12 are formed on the surface of container body 1 by laser processing or the like and the recesses 12 are assembled to form image 11, the diffuse reflectance on the surface of container body 1 becomes higher than that before laser processing as shown in Fig. 1A. That is, the surface becomes cloudy and image 11 is formed as shown in Fig. 1B. The denser the assembly of multiple recesses 12, the more cloudy the surface becomes and the easier it is to see, but the laser processing takes time, which reduces productivity, and the container body 1 may deform due to heat generation or the color may change due to material deterioration, so it is preferable to have the recesses assembled at a density that does not affect visibility.

[0025] The visibility of image 11 is determined not only by the diffuse reflectance of multiple recesses 12 but also by the influence of transmitted light from contents 9 contained in container body 1 (FIG. 1C). When container body 1 is made of a transparent material such as a plastic bottle or glass, the influence of transmitted light from contents 9 contained in container body 1 is particularly large, as shown in FIG. 1C. When an item is contained within the container body, the visibility value of the image including the recess may change depending on the type and color of the item, which may make it difficult to read the barcode, which contains important information. Furthermore, when the image 11 is a collection of a plurality of recesses 12 at a density that does not reduce productivity, the influence of light transmitted through non-recesses 13 must also be taken into consideration. Based on the above, the inventor conducted extensive research and evaluated the visibility including the processing condition of the surface of the container body and the contents contained within the container body, determined whether the barcode formed on the container body can be reliably read, and established an evaluation method for when a barcode is placed on the top surface of the cap, and a method of evaluating a container and visibility that uses these to reliably read the barcode over the entire container.

[0026] First, the method for evaluating visibility will be described. The method for evaluating visibility is to photograph the container body and measure the brightness of the visible image and the portion other than the image. As shown in FIG. 4A, the method of photographing the container body is performed in a darkroom 42 environment in order to eliminate reflections on the surface of the container body 1 due to the shape of the container body 1. In FIG. 4A, 43 is a camera. As shown in FIG. 4B, it is preferable that the light source 41 is a flat light source arranged at a predetermined angle so that the regular reflection component of the surface of the container body 1 is not photographed, and a pair of white diffusion surfaces 44 are installed on the side of the container body 1 in order to reflect the influence of the contents 9 inside the container body 1 in the photographed image. Specifically, the photographing is performed under the following photographing conditions. This makes it possible to obtain an image that is close to that seen in a general environment.

[0027] <Shooting conditions for visibility evaluation method> As shown in FIG. 4A, a camera 43, a sample (container body 1), and a light source 41 are placed in a darkroom. The light source is placed in a position that provides diffuse illumination (a position such as diagonally above the sample where the camera will not detect the regular reflection components on the processing surface; the light source position can also be diagonally below or to the side, etc.). A white surface is placed on the side of the sample to allow for the transmission of light from the surroundings. Set the shooting conditions as follows so that the white reading value does not saturate. -Shooting conditions- Camera: Basler area scan camera acA3088-57μm Lens: Ricoh Lens FL-CC2514-2M (F1.4 f25mm 2 / 3") Aperture: F1.4 Exposure time: 20,000 (μs) Shooting distance: 500mm Light source: LED tracer The state in which the contents are contained within the container body

[0028] The brightness of the image and non-image parts is measured from the captured image. As shown in Figure 5, the brightness is calculated from the output values ​​of the image P and non-image parts Q. The camera output value depends on the size of the image, etc., but is calculated to within a few mm to take into account variations. 2 ~Several tens of mm 2 It is preferable to use an average value of an area of ​​about 100 mm. The conversion to brightness is done by measuring the brightness (L * ) is photographed with a camera, and the camera read value (G signal) and the known brightness can be converted to brightness as follows.

[0029] -G signal and brightness conversion- Photograph a color target (gray chart) with known brightness and approximate it with an nth order polynomial. As an example, convert the G signal into brightness using the following third order polynomial. L * =Lab_1st×G1+Lab_2nd×G2+Lab_3rd×G3+Lab_const Lab_1st=0.461535 Lab_2nd=-0.000281 Lab_3rd=0.000000 Lab_const=1.211053 FIG. 6 is a graph showing the relationship between the G signal and the brightness calculated from the above formula. From FIG. 6, the contribution ratio r 2 =0.997.

[0030] -Subjective evaluation- For samples in which the laser processing conditions for the inside of the container body (PET bottle) were changed, subjective evaluation was performed by changing the contents placed in the samples as shown below, and statistical subjective evaluation scores were obtained for the samples to be evaluated using Chaffe's paired comparison method. Samples: 6 types with different processing conditions Contents: Water, coffee, tea Subjective evaluation method: Chaffe paired comparison method Evaluators: 3 people (each evaluation was conducted twice) First evaluation: All samples were watered Second evaluation: Water (2 bottles), Coffee (2 bottles), Tea (2 bottles) 3rd evaluation: Water (1 bottle), Coffee (3 bottles), Tea (2 bottles) Evaluation environment: Office room

[0031] The obtained subjective evaluation score and the brightness of the image (L * 0), and the difference between the brightness of the image and the brightness of the non-image part (ΔL * ) are shown in Figs. 7 and 8. The larger the subjective evaluation score, evaluated by Chaffe's paired comparison method, the better the visibility in the subjective evaluation. As shown in the area surrounded by the dotted line in Figs. 7 and 8, there are samples with poor correlation. These are the lightness (L * 0) is significantly low, and the brightness difference (ΔL * ) or both of these conditions. In order to obtain a formula with high correlation for such samples, the image brightness L * 0 to (1-exp(ΔL *As shown in Figure 9, Y=(1-exp(-x)) approaches Y=0 as x becomes smaller, so equation (1) is the lightness difference (ΔL * This shows that as the value of the square becomes smaller, visibility tends to deteriorate.

[0032] Therefore, the visibility value is expressed by the following formula (1). Visibility value = b0 L * 0·(1-exp(b1·ΔL * ))···Formula (1) However, in formula (1), L * 0 is the brightness of the image, ΔL * represents the difference between the brightness of the image and the brightness of the non-image part. b0 is a positive real number, and is preferably around 0.2. b1 is a negative real number, preferably around -0.2. The visibility value expressed by formula (1) represents the characteristic that the higher the brightness of the image, the higher the visibility, and that the visibility is lost when there is no difference in brightness between the image and other parts.

[0033] Here, the visibility value calculated using formula (1) with b0 = 0.195 and b1 = -0.193 has a very high correlation (R 2 = 0.943).

[0034] -Barcode reading evaluation of container body- Next, we investigated the relationship between the visibility value of the barcode written on the container body with laser light and the success rate of reading the barcode. For samples in which barcodes were written into the container body (PET bottle) under different laser processing conditions, the contents placed inside the samples were changed as shown below, and an evaluation was conducted to see if the barcode could be read by a barcode reader, and the success rate of reading was calculated. Samples: 6 types with different processing conditions Contents: Water, coffee, milk coffee, tea, soy sauce Barcode reader: BISCOM BC-BR900L (LED type) -Successful reading: Successful reading within 1 second Success rate: Calculated based on the number of successful reads out of 10 read tests Evaluation environment: Office room

[0035] Regarding the barcode reader used here, there are one-dimensional barcode readers and two-dimensional barcode readers, with two-dimensional barcode readers being overwhelmingly superior in terms of reading speed and reading performance for hard-to-read barcodes and bulk reading. On the other hand, considering that barcodes must be readable in a general-purpose manner by the general public, the question is whether reading is successful with a one-dimensional barcode reader with inferior performance. For this reason, the above-mentioned device, which is a one-dimensional barcode reader, was used in this embodiment.

[0036] Figure 11 shows the relationship between the visibility value and the success rate of reading when each of the contents is placed in the sample and the visibility value is measured, and the barcode written in each sample is read with a barcode reader. As a result, it was found that when the visibility value of the barcode expressed by the above formula (1) is 14 or less when each of the contents is placed in each sample, reading becomes unstable, and when it is even lower, reading becomes almost impossible. In other words, by using this index, the reading quality of the barcode written by the laser light can be judged regardless of the contents (liquid) placed in the container body, and when the visibility value is judged to be 14 or less, it can be reliably and quickly judged that it is necessary to place a barcode on the top surface of the cap.

[0037] -Evaluation of the barcode reading on the top of the cap- If it becomes necessary to place a barcode on the top of the cap based on the above judgment, the barcode will be very small. Since there will be many reading errors if the small barcode does not have sufficient contrast, a standard is required to evaluate and judge the symbol contrast of the small barcode on the top of the cap. The symbol contrast can be calculated using the following formula (2). Symbol contrast = |Diffuse reflectance of the non-display part of the identification code -Diffuse reflectance of the display part of the identification code|···Formula (2) That is, in order to design the container as a whole, materials of various colors are used for the cap, but in that case, if the color of the barcode written by printing or the like is the same as the color of the cap, the symbol contrast will be low. In that case, there will be many reading errors with the small barcode on the top surface of the cap.

[0038] In light of these circumstances, we investigated the relationship between the symbol contrast of a reduced-size barcode printed on the top surface of the cap and the success rate of reading the barcode. We changed the color of the cap and the color of the barcode printed on the top of the cap, and evaluated whether the barcode could be read by a barcode reader to determine the success rate of reading. Although we refer to the color of the cap here, in the actual experiment we used a colored polypropylene plate that resembled a cap, and conducted a reading survey of samples with barcodes printed on it in each color, at a size that could be printed on the top of the cap (50% reduction). Cap color (polypropylene plate): white, black, dark green, yellow Barcode color: white, black, light green, light yellow, brown, purple Barcode reduction ratio: 50% Barcode reader: BISCOM BC-BR900L (LED type) -Successful reading: Successful reading within 1 second Success rate: Calculated based on the number of successful reads out of 10 read tests Evaluation environment: Office room

[0039] Figure 12 shows the relationship between the symbol contrast and the reading success rate of the samples mentioned above, which was measured and the barcodes written on each sample were read with a barcode reader. As a result, the reading success rate of 100% was consistently achieved when the symbol contrast of the barcode was 30% or more for each colored cap (polypropylene plate) on which the barcode of each color was printed. In other words, by using this index, it is possible to determine the reading quality of the barcode regardless of the color of the cap used in the design and regardless of the small barcode placed on the top surface of the cap, and it is now possible to quickly and reliably determine that the barcode of a color with a symbol contrast of 30% or more must be placed on the top surface of the cap.

[0040] As mentioned above, when reading a barcode written on a container body with a barcode reader, it was found that the reading success rate is low if the visibility value expressed by the above formula (1) is 14 or less, but the intended purpose is achieved if illustrations and characters can be properly viewed even with a visibility value of 14 or less. We evaluated favorable laser writing conditions for proper visibility in laser processing.

[0041] <Subjective evaluation method> For samples in which images (characters) were laser-processed under the following conditions, a subjective evaluation of the images was conducted, and legibility was rated on a 5-point scale. The results are shown in Figure 13. -Evaluation conditions- ·Judges: 30 people Samples: 10 types in total, with 5.5pt characters created by varying the laser processing conditions and the contents (water, tea, etc.) also varied for each sample. Evaluation environment: In a typical office room - Evaluation method: The evaluation will be made based on the following 5 ranks, and the evaluators will conduct a subjective evaluation. [Evaluation Rank] 1: I can't read 2: I can't read much 3: Readable 4: Good reading 5: Most readable

[0042] As can be seen from the results in Figure 13, since this is a subjective evaluation, there is some variation, but on average, a visibility value of 2 or more rated as rank 3 or higher, meaning that the characters are legible. Also, it was found that a visibility value of 6 or more rated as rank 5 (most easily readable) by all assessors.

[0043] In view of the above, the relationship between the ratio of the area of ​​the plurality of recesses to the area of ​​the image [(area of ​​the plurality of recesses / area of ​​the image)×100] (hereinafter sometimes referred to as the “processing ratio”) and the visibility value was examined. As shown in Figure 14, in the area where the processing ratio is low, there is a correlation between the processing ratio and the visibility value, and the lower the processing ratio, the worse the visibility. When the processing ratio is 50% or more, the visibility value is approximately 5 or more, and even when the processing ratio is 40% or more, the visibility value is 2 or more. In other words, the lower the processing ratio, the higher the productivity. For example, if the processing ratio is 50%, the productivity is doubled by simple calculation. However, when the processing ratio is less than 40%, although the productivity is high, the visibility value is low quality. As the processing ratio increases, the visibility improves, but the visibility value hardly changes at a processing ratio of 85% or more. In other words, the processing ratio shows the maximum visibility value at 85%, and a 15% improvement in productivity can be expected. Thus, it can be seen that a processing ratio of 40% or more and 85% or less is a preferable range in which visibility and productivity are compatible. By setting the processing ratio at 40% or more, it is possible to provide an image with excellent visibility while maintaining high productivity. Furthermore, by setting the processing ratio at 50% or more, it is possible to form an image with the highest judgment rank in the subjective evaluation of the image.

[0044] Next, FIGS. 15A to 15F show specific examples of an image 11 including a plurality of recessed portions and non-recessed portions. The recess 12 is formed from a plurality of processed portions 47, which are arranged in a line. From the standpoint of visibility, it is preferable that the plurality of processed portions 47 are arranged in a line, touching or overlapping each other, as shown in Figures 15B, 15C, and 15F. Furthermore, we compared the writing speed when multiple processed parts 47 are arranged in a line along the first scanning direction (main scanning direction) as shown in Figure 15F, and when the recesses 12 are arranged in a dot pattern along the second scanning direction as shown in Figure 15C. In Figures 15F and 15C, A is set to 120 μm and B is set to 200 μm. In these figures, the cylindrical container is curved in the left-right direction of the figure. Under these conditions, 2 When writing was performed, the result was that the writing speed was more than twice as fast in the writing time when multiple processed parts 47 were arranged in a line along the first scanning direction (main scanning direction) as shown in Fig. 15F compared to the case where the recesses 12 were arranged in a dot pattern along the second scanning direction as shown in Fig. 15C. This means that the productivity is higher when multiple processed parts 47 are arranged in a line along the first scanning direction (main scanning direction). As shown in Figures 15A, 15D, and 15E, when the recesses 12 are arranged in a dot pattern along the first scanning direction, they are easily affected by the transmitted light of the non-recesses 13 around the processed portion 47. However, by providing the non-recesses 13 between the recesses 12, it is possible to further prevent deformation of the main body due to heat generation and color change due to deterioration of the material.

[0045] The processing ratio is calculated from the width A of the processed portion 47 constituting the recess in the second scanning direction perpendicular to the first scanning direction and the width A of the processed portion 47 in the second scanning direction + the width B of the non-recess 13 in the second scanning direction. For example, when forming an image 11 with a resolution of 200 dpi, as shown in FIG. 15A, if the processed portion 47 is in the form of a dot, the processing ratio is calculated as follows: 2 *π / B 2 When A=90 μm and B=127 μm, the processing ratio is 40%. When the processed portion 47 is in contact, for example, when A=127 μm and B=127 μm, the processing ratio is 79%.

[0046] 15B, when the processing parts 47 are arranged in overlapping lines along the first scanning direction, the processing ratio is A / B, and when A=50 μm and B=127 μm, the processing ratio is 40%. When the processing parts 47 are in contact with each other, for example, when A=120 μm and B=127 μm, the processing ratio is 95%. The processed portions 47 can be arranged in either the vertical or horizontal direction (Figure 15C), and the width A of the processed portions 47 in the second scanning direction and the width B of the non-recessed portions 13 in the second scanning direction do not need to be the same within the image 11 (Figures 15D, 15E, and 15F), and may be arranged randomly.

[0047] Furthermore, in terms of improving visibility, it is preferable that the width of the recess in the second scanning direction (sub-scanning direction) perpendicular to the first scanning direction is equal to or less than the width of one dot at a predetermined resolution, for example, 200 dpi. For example, when forming an image with a resolution of 200 dpi, as shown in Figures 16A, 16B, and 16C, if the width C of the second scanning direction (sub-scanning direction) at the smallest dot is 127 μm and the width A of the processed portion 47 in the second scanning direction + the width B of the non-recessed portion 13 in the second scanning direction is 40 μm, laser processing is performed so that three rows of recesses (straight lines) 12 consisting of multiple processed portions 47 are arranged within the width C of the second scanning direction at the smallest dot, thereby making it possible to roughen the surface of the container body more finely and improving visibility.

[0048] In addition to the width B of 40 μm in the second scanning direction in non-recessed portion 13, dots or lines having a width B of 63 μm in the second scanning direction in non-recessed portion 13 are arranged in two rows, and dots or lines having a width B of 80 μm in the second scanning direction in non-recessed portion 13 are arranged in 1.5 rows. Even in these cases, visibility is improved as in the case where the width B of non-recessed portion 13 in the second scanning direction is 40 μm. Furthermore, by making the processing ratio 40% or more and 85% or less, visibility is good, productivity is improved by reducing the processing area, and deformation and material change of the container body due to heat generation can be prevented. In addition, the arrangement of the lines or dots in the processed portion 47 may be either vertical or horizontal, and the width A of the processed portion 47 in the second scanning direction and the width B of the non-recessed portion 13 in the second scanning direction do not need to be the same within the image 11, and may be arranged randomly.

[0049] <Cap> The material, shape, size, structure, color, etc. of the cap are not particularly limited and may be appropriately selected depending on the purpose.

[0050] The material of the cap is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include resin, glass, metal, ceramics, etc. Among these, resin is preferable from the viewpoint of moldability. The resin for the cap may be the same as that for the body of the container. The color of the cap may be, for example, colored opaque, colored transparent, etc. Among these, colored opaque is preferred from the viewpoint of image readability. The shape and size of the cap are not particularly limited as long as they are capable of sealing (closing) the opening of the container body, and can be appropriately selected depending on the purpose.

[0051] The structure of the cap is not particularly limited and can be selected appropriately depending on the purpose, but for example, it is preferable for the cap to have a first part that separates from the container body when opened, and a second part that remains on the container body. The side surface of the first portion is preferably uneven so that the hand does not slip when opening the package, whereas the side surface of the second portion is preferably flat without unevenness.

[0052] In the present invention, the cap has an identification code on the top surface. Examples of identification codes include one-dimensional barcodes and two-dimensional barcodes. Among these, one-dimensional barcodes are preferred from the viewpoint of versatility. Although the term "barcode" generally refers to one-dimensional barcodes, the ISO / IEC standard also refers to two-dimensional barcodes. A barcode is a general term for a code represented by bars called a barcode symbol. Barcodes contain POS (Point Of Sales) information, such as country name, industry, product name, and price, which are necessary for distribution and product management, and can be read by a handheld terminal or barcode reader.

[0053] Here, FIG. 17 is a schematic diagram showing an example of a one-dimensional barcode. The "quiet zone (margin)" is the blank space on the left and right of the barcode symbol. If this blank space is insufficient, the barcode symbol will not be readable. It must be at least 10 times the narrow bar width (minimum element) on both sides.

[0054] "Start / stop characters" are characters that indicate the beginning and end of data. The "start / stop characters" vary depending on the type of barcode; for CODE39 they are "*", and for NW-7 they are "a", "b", "c", and "d".

[0055] "Data (message)" is a bar pattern of characters (numbers, letters, etc.) represented as data, lined up from the left. In Figure 17, the bar patterns representing the characters 0, 1, and 2 are lined up in order from the left to represent the data "012."

[0056] A "check digit" is a calculated number that is added immediately after the barcode data to check for misreading.

[0057] The "length of the barcode" refers to the length including the quiet zones on either side. In other words, if the barcode, including the quiet zones, is not within the reading width of the barcode reader, it cannot be read.

[0058] It is desirable to secure the maximum "barcode height" that can be printed. If the height is too low, the laser light may deviate from the barcode, making it difficult to read stably. It is recommended to secure at least 15% of the barcode length.

[0059] FIG. 18 is a diagram illustrating bars and spaces in a one-dimensional barcode. A one-dimensional barcode is made up of a combination of thin and thick bars and spaces, and each bar and space is called as shown in Figure 18.

[0060] In one aspect of the present invention, the identification code is a one-dimensional barcode, and an image is formed on an extension line of the longitudinal direction of the bar of the one-dimensional barcode. According to this aspect, it is possible to reduce barcode reading errors and improve operability during scanning.

[0061] Fig. 19 is a diagram showing the positional relationship between the one-dimensional barcode provided on the top surface of the cap and the image provided on the container body. As shown in Fig. 19, an image 11 is formed on the container body 1 on the longitudinal extension of the bars of the one-dimensional barcode 2 provided on the top surface of the cap 8. That is, the bars of the one-dimensional barcode 2 are provided in a fence-like shape relative to the image 11 on the container body 1. Reading experiments were conducted with a direction-dependent barcode, using a container in which a one-dimensional barcode 2 is arranged so that an image 11 of the container body 1 is formed on the longitudinal extension of the bar, as shown in Figure 19, and a container in which the orientation of the one-dimensional barcode is not associated with the image of the container body. As a result, in containers where the orientation of the one-dimensional barcode was not associated with the image of the container body, the task of checking the orientation of the barcode on the top of the cap occurred every time a read was made. However, in the case of a container like the one shown in Figure 19, the orientation of the barcode on the top of the cap can be seen by looking at the image of the main container, so by getting used to the relative positions, it became unnecessary to check the orientation of the barcode on the top of the cap every time, and the time required to read 100 bottles was reduced by approximately 150 seconds. The present invention also has the advantage that it allows for intuitive operation when reading bar codes at a cash register or the like, and reduces errors in reading bar codes.

[0062] In one aspect of the present invention, the identification code is a one-dimensional barcode, and the length of the bar in the longitudinal direction of the one-dimensional barcode is different between the center and the ends in the lateral direction of the bar of the one-dimensional barcode. According to this aspect, it is possible to reduce barcode reading errors and improve operability during scanning.

[0063] The 13-digit barcode JAN-13, which is a commercial barcode commonly used in Japan, is larger than the caps used for beverage bottles at its specified size, and so needs to be reduced when printed on the cap. The international standard for barcodes (ISO) requires a reduction ratio of up to 80% to guarantee reading quality, and so a barcode needs to be smaller than the specified ratio to be placed on a cap. However, in order to maintain the reading quality of the barcode, it is preferable not to reduce the size of the barcode as much as possible. For example, when a barcode is placed on the top surface of a normal PET bottle cap as shown in FIG. 20A, the reduction ratio is about 50%, and in this case, if printing is performed with low contrast, there will be many reading errors. In this case, since the cap is circular, as shown in FIG. 20B, by making the center and ends of the one-dimensional barcode placed on the top surface of the cap 8 different lengths in the short direction, it is possible to place a barcode of the maximum size in the horizontal direction, and furthermore, the bars in the center of the barcode can be made longer in the vertical direction, so that it can be recognized as a larger size. In a reading test, the barcode of this embodiment, each of which has a symbol contrast of 25%, was compared with a normal barcode with a reduction ratio of 50%, and the reading success rate improved from 30% to 80%. In other words, even if the combination of a cap color desired for design and a barcode color desired for design has low symbol contrast, the present invention has increased the possibility of selecting that combination.

[0064] In one aspect of the present invention, the image has a higher diffuse reflectance in the image portion than in the non-image portion, and the light and dark of the image is reversed from that of the original image, and the identification code has a lower diffuse reflectance in the display portion than in the non-display portion, and the light and dark of the identification code is not reversed from that of the original image. This aspect reduces barcode reading errors. Barcodes are recognized as either positive images, with dark bars and light spaces, or negative images, with the light and dark portions reversed. When marking a plastic bottle with a laser, the processed area becomes a bright negative image. Most commercially available barcode reading devices can handle both positive and negative images, but there are some that can only handle positive images. Therefore, by making the barcode on the cap a positive image, reading errors can be reduced.

[0065] (Containment Unit) The container of the present invention includes the container of the present invention and an item contained in the container. The contained object may be, for example, a liquid, a gas, or a granular solid. Examples of liquids include water, tea, coffee, black tea, soft drinks, etc. When the content is a liquid beverage, it often has a color such as transparent, white, black, brown, or yellow. Examples of gases include oxygen, hydrogen, and nitrogen. Examples of granular solids include pieces or particles of fruit pulp, vegetables, nata de coco, tapioca, jelly, konjac, etc.

[0066] <Container manufacturing method and container manufacturing device> The method for manufacturing the container used in the present invention is a method for manufacturing the container of the present invention, and includes an irradiation step in which laser light is irradiated onto the container body to form an image, and preferably includes at least one of a rotation step and a movement step, and further includes other steps as necessary. The container manufacturing apparatus used in the present invention is an apparatus for manufacturing the container of the present invention, and has an irradiation means for irradiating the container body with laser light to form an image, and preferably has at least one of a rotation means and a movement means, and further has other means as necessary.

[0067] The spot diameter of the laser light is preferably 1 μm to 200 μm, more preferably 10 μm to 100 μm. If the spot diameter is smaller than 1 μm, it becomes close to the wavelength of visible light, and the structure processed with the beam spot diameter cannot scatter the light, and cannot be clouded. If the spot diameter is larger than 200 μm, the structure can be recognized by the human eye.

[0068] It is preferable to form an image by controlling the intensity of the laser light. It is preferable to form an image by scanning the laser light. It is preferable to form an image by independently controlling the intensities of a plurality of laser beams emitted from a plurality of laser light sources.

[0069] In the method for manufacturing a container used in the present invention, a container body on which an image is to be drawn is rotated and irradiated with laser light to form an image. Regarding the configuration of the device, there are two cases: the laser position is fixed and the container side is moved, and the container side is fixed and the laser position is moved. In addition, when the container body is moved, there are cases where the image is formed by synchronous control, such as rotating the container body by a certain angle, performing laser drawing, and then rotating the container body by the same angle and performing laser drawing again, or where the container body is rotated at a constant speed and laser drawing is performed. The container holding part may be the mouth, the body, or the bottom. The container body may be placed vertically, horizontally, or at an angle during processing.

[0070] Incidentally, marking may be performed from one side when the container body passes through a conveyor or the like, or marking may be performed simultaneously from a plurality of places when the container body passes through a conveyor or the like.

[0071] The wavelength of the laser light source is preferably not only in the ultraviolet region or the visible light region, but also in the near infrared region to the mid-infrared region, specifically in the wavelength region of 1,200 nm or more and 1,500 nm or less.

[0072] For example, wavelengths in the near-infrared to mid-infrared regions are suitable for high speed processing when opacifying the material by foaming (thermal denaturation) and for facilitating the formation of arrays of devices.Wavelengths in the ultraviolet region are suitable for processing by ablation, as the light intensity of the laser light can be increased. Furthermore, for each wavelength band, there are wavelengths whose absorptance in the container body is significantly higher than the surrounding wavelengths, and it is particularly preferable to use these wavelengths.

[0073] Although the embodiment of the present invention has been described in detail above, the present invention is not limited to the above embodiment, and various modifications may be made without departing from the gist of the present invention.

[0074] For example, aspects of the present invention are as follows. <1> A container having a container body and a cap for sealing a content in the container body, The cap has an identification code on the top surface thereof, the container body includes a plurality of recesses and has an image having an area larger than that of the identification code; The container is characterized in that the difference in diffuse reflectance between the display portion and the non-display portion of the identification code is greater than the difference in diffuse reflectance between the image portion and the non-image portion. <2> The container body has a visibility value represented by the following formula (1) that is equal to or greater than a predetermined value. <1> It is a container as described above. Visibility value = b0 L * 0·(1-exp(b1·ΔL * ))···Formula (1) In the above formula (1), L * 0 is the brightness of the image, ΔL * represents the difference between the brightness of the image and the brightness of the portion other than the image, b0 is a positive real number, and b1 is a negative real number. <3> The visibility value is 2 or more. <2> It is a container as described above. <4> When the visibility value represented by the following formula (1) in a state in which the content is contained in the container body is 14 or less, The symbol contrast of the identification code of the cap, which is expressed by the following formula (2), is 30% or more. <1> It is a container as described above. Visibility value = b0 L * 0·(1-exp(b1·ΔL * ))···Formula (1) In the above formula (1), L * 0 is the brightness of the image, ΔL * represents the difference between the brightness of the image and the brightness of the portion other than the image, b0 is a positive real number, and b1 is a negative real number. Symbol contrast = |Diffuse reflectance of the non-display portion of the identification code-Diffuse reflectance of the display portion of the identification code|... Formula (2) <5> The image has a non-recessed portion. <1> from <2> and <4> 1 is a container according to any one of the preceding claims. <6> a ratio of the area of ​​the plurality of recesses to the area of ​​the image [(area of ​​the plurality of recesses / area of ​​the image)×100] is 40% or more and 85% or less; <1> from <2> and <4> 1 is a container according to any one of the preceding claims. <7> The recess is formed of a plurality of processed portions, and the plurality of processed portions are linearly arranged along a first scanning direction. <1> from <2> and <4> 1 is a container according to any one of the preceding claims. <8> a width of the recess in a second scanning direction perpendicular to the first scanning direction is equal to or less than one dot width at a predetermined resolution; <7> It is a container as described above. <9> the identification code is a one-dimensional barcode, The image is formed on an extension line of a bar in the longitudinal direction of the one-dimensional barcode. <1> from <2> and <4> 1 is a container according to any one of the preceding claims. <10> the identification code is a one-dimensional barcode, The length of the bar in the longitudinal direction of the one-dimensional barcode is different between the center and the end in the lateral direction of the bar of the one-dimensional barcode. <1> from <2> and <4> 1 is a container according to any one of the preceding claims. <11> the image has a larger diffuse reflectance in the image portion than in the non-image portion, and light and dark are inverted from the original image; the identification code has a smaller diffuse reflectance of a display portion of the identification code than a non-display portion thereof, and the light and dark of the identification code is not inverted from that of an original image; <1> from <3> 1 is a container according to any one of the preceding claims. <12> The above <1> from <2> and <4> and an object contained in the container.

[0075] The above <1> from <11> The container according to any one of the above, <12> According to the container described above, the conventional problems can be solved and the object of the present invention can be achieved. [Explanation of symbols]

[0076] 1 Container body 2. One-dimensional barcode 7 Containment Unit 8 Cap 9 Contents 11 Image (character) 12 Concave (straight line) 13 Non-recessed 47 Processing Department [Prior art documents] [Patent documents]

[0077] [Patent Document 1] JP 2021-176648 A

Claims

1. A container including a container having a container body and a cap that seals the contents in the container body, and the contents contained in the container, A one-dimensional barcode is provided on the upper surface of the cap, the container body includes a plurality of recesses and has an image with an area larger than that of the one-dimensional barcode; The visibility value represented by the following formula (1) is 2 or more and 14 or less, A container in which the symbol contrast of the one-dimensional barcode on the cap, as expressed by the following formula (2), is 30% or more. Visibility value=b0·L*0·(1−exp(b1·ΔL*)) Formula (1) In the above formula (1), L*0 represents the brightness of the image obtained based on the G signal in an image of the container photographed in a darkroom environment with a pair of white diffusion surfaces placed on the side surfaces of the container body, and a polynomial obtained by photographing a color chart with known brightness and approximating the relationship between the G signal and brightness using an n-th order polynomial; ΔL* represents the difference between the brightness of the image obtained based on the G signal in the photographed image and the polynomial, and the brightness of the portion of the container body other than the image; b0 is 0.195, and b1 is −0.

193. Symbol contrast=|Diffuse reflectance of the non-display portion of the one-dimensional barcode−Diffuse reflectance of the display portion of the one-dimensional barcode|...Equation (2)

2. A container as described in claim 1, wherein the one-dimensional barcode is printed in ink.

3. A container as described in claim 1 or 2, wherein the container is made of resin.

4. A container as described in Claim 3, wherein the container is made of polyethylene terephthalate.

5. 5. The container of claim 1, wherein the image is non-recessed.

6. 6. The container according to claim 1, wherein the ratio of the area of ​​the plurality of recesses to the area of ​​the image [(area of ​​the plurality of recesses / area of ​​the image) x 100] is 40% or more and 85% or less.

7. A container described in any one of claims 1 to 6, wherein the height of the one-dimensional barcode is 15% or more of the length of the one-dimensional barcode.

8. A container described in any one of claims 1 to 7, wherein the size of the one-dimensional barcode is smaller than the reduction ratio relative to the specified size guaranteed by international standards.

Images