Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
  • B60C13/00—Tyre sidewalls; Protecting, decorating, marking, or the like, thereof
  • B60C13/001—Decorating, marking or the like
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29D—PRODUCING PARTICULAR ARTICLES FROM PLASTICS OR FROM SUBSTANCES IN A PLASTIC STATE
  • B29D30/00—Producing pneumatic or solid tyres or parts thereof
  • B29D30/06—Pneumatic tyres or parts thereof (e.g. produced by casting, moulding, compression moulding, injection moulding, centrifugal casting)
  • B29D30/08—Building tyres
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29D—PRODUCING PARTICULAR ARTICLES FROM PLASTICS OR FROM SUBSTANCES IN A PLASTIC STATE
  • B29D30/00—Producing pneumatic or solid tyres or parts thereof
  • B29D30/06—Pneumatic tyres or parts thereof (e.g. produced by casting, moulding, compression moulding, injection moulding, centrifugal casting)
  • B29D30/72—Side-walls
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B44—DECORATIVE ARTS
  • B44C—PRODUCING DECORATIVE EFFECTS; MOSAICS; TARSIA WORK; PAPERHANGING
  • B44C1/00—Processes, not specifically provided for elsewhere, for producing decorative surface effects
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
  • B60C11/00—Tyre tread bands; Tread patterns; Anti-skid inserts
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
  • B60C11/00—Tyre tread bands; Tread patterns; Anti-skid inserts
  • B60C11/24—Wear-indicating arrangements
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
  • B60C13/00—Tyre sidewalls; Protecting, decorating, marking, or the like, thereof
  • B60C13/02—Arrangement of grooves or ribs
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60R—VEHICLES, VEHICLE FITTINGS, OR VEHICLE PARTS, NOT OTHERWISE PROVIDED FOR
  • B60R13/00—Elements for body-finishing, identifying, or decorating; Arrangements or adaptations for advertising purposes

Definitions

• the present invention relates to a tire for a motor vehicle having a tread and a sidewall, said tire comprising on the tread and / or said sidewall a marking.
• the tires have markings on their tread and / or their sidewall which are increasingly made from source images which are printed and which are in particular photographs, or works of art. artists, graphic designers.
• the said source markings are composed of different shades of color that can be transposed into different gray levels.
• WO 2013/1 13526 discloses a tire having a marking on a sidewall.
• This marking consists of a realistic representation of a photograph. More particularly, the marking is composed of a plurality of adjacent ribs having a generally triangular section. The space between two adjacent ribs is filled with a complementary material to a certain level of filling. The level of filling of the complementary material locally determines a gray level of the marking.
• the object of the invention is to propose a solution for producing on a tire complex markings, of photographic representation type, in a simpler and more economical manner than in the prior art.
• Rubber material means a diene elastomer, that is to say in known manner an elastomer derived from at least in part (ie homopolymer or copolymer) of monomers dienes (monomers carrying two carbon-carbon double bonds, conjugated or not).
• tread of a tire means a quantity of rubber material delimited by lateral surfaces and by two main surfaces, one of which, called a tread surface, is intended to come into contact with a road surface. when the tire is rolling.
• sidewall of a tire means a side surface of the tire disposed between the tread of the tire and a bead of the tire.
• String means a filamentary element whose height is at least equal to 2 times the diameter of a disc of the same area as the average section of the strand.
• Standard means elongate strands having a length at least twice their height.
• the luminosity is expressed on a scale from 0 to 100 according to the colorimetric model L * a * b * established by the CIE (International Commission on Illumination) in 1976.
• the value 100 represents white or total reflection; the value 0, black or total absorption.
• a * and b * are chromaticity coordinates.
• the color model L * a * b * thus defines a chromaticity diagram.
• a * and b * indicate the direction of the colors: + a * goes to red, -a * to green, + b * to yellow, and -b * to blue.
• the center of the diagram is achromatic. As the values a * and b * increase, and as we move away from the center of the diagram, the saturation increases.
• Pattern means a geometric element protruding from the tire such as a strand or a sipe, or a geometric element recessed relative to the tire such as a hole or a streak.
• the invention relates to a rubber tire comprising a tread and a sidewall, said tire comprising on the tread and / or said sidewall a marking.
• the marking is divided into a plurality of base areas of the same size, each base area being writable in a circle of diameter equal to 8 mm.
• Each base area has 0 to N patterns.
• the patterns are integral with the tire to define a gray level of the base area among N + 1 gray levels.
• the gray level of a base area depends on the number of patterns present in that base area.
• the marking on the tire comprises at least 5 gray levels. [15]
• the invention thus proposes to carry out a complex marking on a tire, this marking comprising at least 5 gray levels.
• each basic zone comprises patterns made of material with the tire. These patterns have the property of absorbing the incident light before returning it.
• the gray level of this base area is changed.
• the larger the number of patterns in the base area the more the base area becomes black for an observer.
• the tire may further comprise one or more additional characteristics from the following:
• a base area is divided into N parts, a portion comprising at most one pattern.
• the patterns are identical.
• a base area is a polygon each side of which is between 0.02mm and 5mm.
• a pattern is composed of a protruding element with respect to the tread and / or said sidewall.
• said protruding element is a lamella of average width between 0.02 mm and 0.25 mm.
• said protruding element is a strand of average section between 0.0005 mm 2 and 1 mm 2 .
• said protruding element is a side parallelepiped between 0.05 mm and 0.5 mm, height between 0.05 mm and 0.5 mm.
• a pattern is composed of a hollow element relative to the tread and / or said sidewall.
• Marking areas are thus more durable. Indeed, as a zone is composed of hollow elements relative to the tread and / or the sidewall, the impact of friction of a roadway on an area is lower.
• said hollow element forms an opening on the tread and / or said sidewall of equivalent diameter between 0.01 mm and 1.2 mm.
• FIG. 1 shows schematically a perspective view of a part of a tire comprising a tread and a sidewall, said sidewall comprising a marking according to the invention according to a first embodiment
• FIG. 2 diagrammatically represents a perspective view of a portion of a tire comprising a tread and a sidewall, said tread comprising a marking according to the invention according to a second embodiment
• FIG. 3a schematically represents an enlarged view of the marking of FIG. 1 or FIG.
• FIG. 2 is a zoom on part of said marking of Figure 3a;
• FIG. 4 schematically represents a base zone of FIG. 3b, said zone comprising a single portion according to a first non-limiting embodiment;
• Fig. 5 shows the base area of Fig. 4, said part of the base area including an example of a non-limiting pattern;
• FIG. 6 diagrammatically represents a base zone of FIG. 3b, said base zone comprising a plurality of parts according to a second nonlimiting embodiment and according to a first non-limiting variant embodiment;
• FIG. 7 schematically represents a base zone of FIG.
• FIG. 8 diagrammatically represents six basic zones of FIG. 6, each base zone comprising square-shaped portions according to a first non-limiting variant embodiment, and each base zone comprising, according to a first nonlimiting example, between 0 and N patterns according to the gray level defined by said base area, a pattern being made in a portion of said base area;
• FIG. 9 schematically represents six basic zones of FIG. 7, each base zone comprising parts of rectangular shape according to a second nonlimiting variant of embodiment and each base zone comprising according to a first nonlimiting example between 0 and N patterns according to the gray level defined by said base area, a pattern being made in a portion of said base area;
• FIG. 8 diagrammatically represents six basic zones of FIG. 6, each base zone comprising square-shaped portions according to a first non-limiting variant embodiment, and each base zone comprising, according to a first nonlimiting example, between 0 and N patterns according to the gray level defined by said base area, a pattern being made in a portion of said base area;
• FIG. 9 schematically represents six basic zones
• FIG. 10 schematically represents six basic zones of FIG. 6, each base zone comprising square-shaped portions according to a first non-limiting variant embodiment and each base zone comprising, according to a second nonlimiting example, between 0 and N patterns according to the gray level defined by said base area, a pattern being made in a portion of said base area;
• FIG. 11 schematically represents six basic zones of FIG. 7, each base zone comprising parts of rectangular shape according to a second nonlimiting variant of embodiment and each base zone comprising, according to a second nonlimiting example, between 0 and N patterns according to the gray level defined by said base area, a pattern being made in a portion of said base area;
• FIG. 12 represents a plurality of patterns in the base zones of FIG. 6 or FIG.
• FIG. 13 shows a plurality of patterns in the base zone of FIG. 6, according to a second nonlimiting variant of a first embodiment of the patterns in which the patterns are composed of the same element in protuberance
• FIG. 14 shows a plurality of patterns in the base zone of FIG. 6, according to a third nonlimiting variant of a first embodiment of the patterns in which the patterns are composed of the same protruding element
• FIG. 15 represents a plurality of patterns in the base zone of FIG. 6, according to a second embodiment of the patterns in which the patterns are composed of the same hollow element;
• FIG. 16 is an enlarged view of a recess of a recessed member of Fig. 15;
• Figure 17 is a flowchart of a method of performing a marking on a tire from a source image; and
• Fig. 18 is a flowchart of the method of Fig. 17, said method comprising additional steps.
• Figures 1 and 2 are shown a portion of the tire 1 having a tread 2 and a sidewall 3, said tire 1 comprising on the tread 2 and / or said flank 3 a marking 4.
• said marking 4 represents a unit of meaning which is here a face.
• Figure 1 shows a portion of the tire 1 having a tread 2 and a sidewall 3 according to a first non-limiting embodiment. According to this mode, the flank 3 has on its surface 30 a marking 4.
• Figure 2 shows a portion of the tire 1 having a tread 2 and a sidewall 3 according to a second non-limiting embodiment.
• the tread 2 has grooves 21 (also called tread patterns) and a tread surface 20 intended to come into contact with the ground. According to this mode, the tread 2 comprises on its running surface 20 a marking 4.
• said marking 4 is composed of a plurality basic areas 50.
• Figure 3b is a zoom on part of the marking 4, namely here on an eye of the face.
• the base areas 50 are identical, namely they have the same shape. We can thus observe a plurality of base areas 50 of square shape in the non-limiting example.
• Each base zone 50 makes it possible to define a particular level of gray Nx.
• the marking 4 comprises for example a first gray level Nx1 which is a light gray (on the left of the eye), a second gray level Nx2 which is a dark gray (above the eye) and a third level of gray Nx3 which is black (in the eye) etc.
• a base area 50 is a polygon each side of which is between 0.02mm and 5mm.
• the low limit of 0.02mm makes it easy to produce areas at the industrial level because the base area 50 is not too small.
• the high limit of 5 mm makes it possible to obtain basic zones 50 which are not too large so that the marking 4 is not too coarse to the naked eye.
• the base areas 50 are all the same size.
• the basic zones are writable in a circle of diameter equal to 8 mm.
• the basic zones are writable in a circle of diameter equal to 2 mm.
• a base area 50 is divided virtually into one or more portions 500. It will be seen later that these portions 500 correspond to portions on an image in computer file format.
• Part 500 makes it possible to define a single level of gray Nx defined from two levels of gray Nx. There is thus a first gray level corresponding to the white color, and a second gray level corresponding to the black color.
• a base area 50 and therefore a portion 500 comprises between 0 and 1 pattern 6 according to the gray level of said base area 50 (part 500).
• the portion 500 of the base area 50 does not include any pattern, as shown in Figure 4, while to achieve the black color, the portion 500 of the base area 50 includes a Pattern 6 (shown in gray) in Figure 5.
• a base area 50 comprises a plurality of portions 500, namely N parts (N> 1), an area for defining a gray level Nx among N + 1 gray levels Nx.
• the part 500 form a square as illustrated in Figure 6.
• a base area 50 comprises nine squares 500.
• the portion 500 forms a rectangle as illustrated in FIG. 7.
• a base zone 50 comprises five rectangles 500.
• a gray level Nx is achieved by the number of patterns 6 in a base area 50, each base area 50 comprising between 0 and N patterns 6 to define a level of gray Nx among N + l gray levels.
• FIG. 8 and FIG. 9 respectively illustrate nine parts 500 and five parts 50 that make it possible to define a maximum of ten gray levels Nx and six gray levels Nx, respectively.
• a portion 500 of a base area 50 comprises either zero pattern 6 or a pattern 6.
• a portion 500 has a square shape and in front view, the base of the pattern 6 is circular in a non-limiting manner.
• a portion 500 has a rectangular shape and in front view, the base of the pattern 6 is rectangular.
• the first base area 50 has no pattern 6. This allows for a gray level of white color.
• the following four zones 50 respectively comprise 1, 2, 3 and four circular base patterns 6 making it possible to achieve increasingly darker gray levels, until reaching the darkest gray level represented by the last basic zone. 50.
• This last base zone 50 here comprises five patterns 6. It may be noted in this variant of realization, that the circular base of a pattern 6 almost completely fills a portion 500.
• the advantage is to juxtapose patterns maximizing the absorption of light, such as cones for example, and thus maximize the contrast obtained between the areas with multiple patterns and areas devoid of reasons.
• the first base area 50 has no reason
• the following four basic zones 50 respectively comprise 1, 2, 3 and four rectangular base patterns 6 making it possible to achieve increasingly darker gray levels, until reaching the darkest gray level represented by the last zone.
• This last base zone 50 here comprises five patterns 6. It may be noted in this variant embodiment that the rectangular base of the pattern 6 does not completely fill a portion 500. The pattern 6 extends in effect only on half the surface of a 500 part. The advantage of this method is industrial. Laser machining machines make it possible to dig furrows quickly. [53] It will be noted that the distribution of the reasons 6 in the different parts
• a base area 50 can be done randomly (respecting the number of patterns in an area to achieve the desired level of gray Nx) as is the case in Figures 8 and 9, or more as ordered in Figures 10 and 11.
• a pattern 6 is arranged next to another pattern to achieve the desired gray level Nx.
• a gray level Nx can be achieved by a plurality of patterns 6 which are adjacent to each other.
• Each pattern 6 having the property of deflecting, dispersing or absorbing the incident light, it is therefore non-tangent to the surface of the tread and / or the sidewall, and is either recessed or protruding as we go see it below.
• Two non-limiting embodiments of a pattern 6 are shown below.
• the pattern 6 is composed of a protruding element with respect to the tread 2 and / or said sidewall 3 and more particularly with respect to the surface 30 of the sidewall 3 in the case illustrated in Figure 1 or the tread surface 20 of the tread 2 in the case illustrated in FIG. 2.
• a base zone 50 thus comprises between 0 and N elements in protuberance, each of the elements being distributed in a part 500.
• a pattern 6 (such as a strand or a slat) is integral with the tread and / or the sidewall, ie it is made of the same rubber material as the tread and / or the sidewall. This produces a marking without adding another material.
• protruding elements make it possible to obtain on the other hand, a visual of the "velvet” type because the elements in protuberance absorb the light and thus make a base zone 50 blacker than the tread and / or the sidewall, and secondly, a touch of the "velvet” type ", Said protruding elements thus provide a base area 50 pleasant to the touch.
• a protruding element is described hereinafter according to various nonlimiting embodiments and in relation to the various embodiments of a portion 500 (square or rectangular shape) of a base zone 50.
• said protruding element is a lamella 8 with an average width of between 0.02 mm and 0.25 mm as illustrated in FIG. 12. It will be noted that the average width corresponds to the average of the widths 1 measured at regular intervals in the height H1 of the lamella, the height of each lamella being between 0.05 and 0.5 mm.
• the base area 50 comprises only one portion 500, or it comprises only one lamella 8 or no lamella 8 so as to achieve one of the two levels of gray Nx desired.
• a portion 500 comprises a single lamella 8 or no lamella 8.
• a portion 500 may comprise only one lamella 8.
• the portion 500 is a square, various alternative embodiments are possible for the protruding element and are described hereinafter.
• said protruding element is a strand 9 having a mean section S between 0.0005 mm 2 and 1 mm 2 . It should be noted that the average section of each strand corresponds to the average of sections S measured at regular intervals from the base of the strand.
• the strands 6 have a generally conical shape with a decreasing section in the Hb height of these strands.
• the base area 50 comprises only one portion 500, or it comprises only one strand 9, or no strand 9 so as to achieve one of the two levels of gray Nx desired.
• a portion 500 comprises a single strand 9 or no strand 9.
• a portion 500 may comprise only one strand 9.
• said protruding element is a parallelepiped 10 side C between 0.05 mm and 0.5 mm, Hp height between 0.05 mm and 0.5 mm.
• the base area 50 comprises only one part 500, it comprises only one parallelepiped 10, or no strand 10 so as to achieve one of the two levels of gray Nx desired.
• a portion 500 comprises a single parallelepiped 10 or no parallelepiped 10.
• a portion 500 may comprise only one parallelepiped 10.
• a white color is obtained.
• the white color is achieved by a smooth surface (that of the tread 2 and / or the sidewall 3) which has a very low surface roughness Ra parameter.
• the arithmetic mean-deviation parameter Ra representative of the surface roughness is less than 30 ⁇ . This smooth surface returns a maximum of incident light. The amount of light reflected by a base area 50 of white color is thus maximized.
• the target gray level to be achieved defines the area percentage of the base area 50 to return light, with the remainder of the base area 50 at most absorbing light.
• a pattern 6 is composed of a hollow element 12 (also called hole) with respect to the tread 2 and / or said sidewall 3 and more particularly with respect to the surface 30 of the sidewall 3 in the case illustrated in Figure 1 or the tread surface 20 of the tread 2 in the case illustrated in Figure 2.
• a hollow element 12 is composed of an opening 13 on the surface and an associated cavity 14 extending in the depth of the surface.
• a pattern 6 is composed of a hollow element which forms an opening 13 on the tread 2 and / or said sidewall 3 of equivalent diameter Dt of between 0.01 mm and 1.2 mm.
• An opening 13 extends into the depth of the surface to form a cavity 14.
• a base zone 50 thus has between 0 and N recessed elements, each element being distributed in a portion 500.
• cavities 14 The effect of these cavities 14 is to "trap" a large amount of incident light rays that meet a base area 50, but also to provide greater durability of the base area 50. Indeed, as the cavities 14 are recessed in the surface, the impact of the mechanical attacks on the base area 50, such that the friction of a roadway is lower than for protuberances.
• the hollow elements make it possible to obtain a "velvet” type visual because the cavities absorb the light and thus make a base zone 50 darker than the tread and / or the sidewall.
• a cavity 14 has a depth of at least 0.1mm. In a non-limiting embodiment variant, a cavity 14 has a depth of between 0.2 mm and 0.6 mm. In this way, it is ensured that a large quantity of incident light rays which meet a base zone 50 is trapped by said zone, and since the depth of the cavities is limited, it is also avoided to degrade the mechanical strength of the zone too much. surface 20 and / or 30.
• Figure 15 illustrates the hollow element 12 according to a non-limiting variant of this second embodiment.
• a cavity 14 is in the form of a cone which extends in the depth of the surface 20 and / or 30 and opens out onto said surface forming a circular opening 13.
• a cavity 14 thus has a section which decreases in the depth of the surface. In this way, the contrast of the base area 50 with respect to the remainder of the tire is improved.
• FIG. 16 is a zoom on a cavity 14 of a hollow element of FIG. 15.
• a cavity has at least one wall 16 which, in a sectional view, forms a angle ⁇ between 10 ° and 60 ° relative to a direction Z perpendicular to the base zone 50.
• the protruding elements depending on the desired gray level Nx, the number of recessed elements in a base zone 50 is varied.
• the marking 4 on tire 1 made of rubber material comprising a tread 2 and a sidewall 3 is made from a source image 4 'by means of an MTH production method illustrated in FIGS. 17 and 18.
• the source image 4 ' is an image in the form of a computer file such as files of type bitmap or jpeg (also called digital image). Moreover, its resolution is generally quite high, for example of the order of 3000 pixels by 3000 pixels.
• the MTH production method comprises: a first processing of the source image 4 'into a target image 4 "composed of a plurality of identical basic areas 50, each zone basic 50 defining a level gray Nx among N + 1 levels of gray Nx (illustrated step F1 (4 ', 4 ", 50, Nx));
• the marking 4 from said target image 4 " comprising a plurality of patterns 6 (step illustrated GRAV (4, 6).
• the first processing of the source image 4 ' will make it possible to obtain a target image 4 "made up of a plurality of identical basic areas 50.
• the number of parts 500 in a region is also defined.
• These parts 500 will thus allow the distribution and positioning of the patterns 6 in marking 4 and assisting in the industrial production of said marking 4.
• This processing is done by an appropriate image processing software.
• This processing thus makes it possible to define the desired number of gray levels Nx in the target image 4 ". It will be noted that, starting from 8 gray levels, an observer of the tire begins to no longer distinctly perceive the discontinuities of gray levels.
• the rubber material of the tire 1 absorbs more than 90% of the incident light.
• the processing thus reduces the number of gray levels Nx relative to the number of gray levels defined in the source image 4 '.
• the number Nb of gray levels is between 2 and 10.
• a base area 50 of the target image 4 "will have only one part 500 as described above. If we want to obtain 10 levels of gray a base area 50 will have 9 parts 500 as previously described.
• the target image 4 "obtained after this first step is an image which is always in the form of a computer file.
• the selection of one or more patterns 6 to achieve the levels of gray Nx of said base areas 50 makes it possible to define said patterns as input parameter of the machine M which will perform the marking 4.
• a single pattern 6 will be selected.
• a base area 50 will comprise between zero and N occurrences of the same pattern 6.
• a plurality of patterns will be selected.
• a base area 50 will comprise between zero and N patterns 6 of different shape.
• marking 4 is carried out by laser etching by means of a laser engraving machine M on a mold or directly on said tire 1.
• the etching of the marking 4 is in a first embodiment carried out on a mold. In a second embodiment, it is carried out directly on said tire 1. Thus, the etching of the marking 4 is carried out before or after firing of the tire 1.
• Said etching comprises the etching of a plurality of patterns 6, each base zone 50 composing the marking 4 comprising between 0 and N patterns 6 to define a level of gray Nx among N + l gray levels Nx. A level of gray Nx is thus achieved by a repetition of a same pattern 6 (in the case where a single pattern is used) or a plurality of patterns 6.
• the laser engraving machine M is in a non-limiting example a pulsed laser which comprises in a non-limiting example a power of 50 W and a speed of 1000mm / s and operates at a frequency of 50kHz.
• said method further comprises the definition of the pitch Pa between two adjacent patterns 6 to be made on the tire 1 (step shown in dotted lines SELEC (Pa)).
• the choice of the pitch Pa to be made on the tire 1 is set on the laser engraving machine M.
• the pitch Pa is defined as the input parameter of the machine M.
• the not Pa is between 0.2mm and 1mm. This allows a realization at the industrial level. It should be noted that the smaller the pitch Pa, the more precise the marking will be.
• a pitch Pa between two adjacent patterns 6 is defined with respect to a median passing through the center of each pattern. This step can be performed at any time in the process.
• the MTH method further comprises a transformation of the source image 4' in color into a source image 4 'in levels gray (step shown in dotted lines TRANS_CO (4 ', Nx) in FIG. 18).
• the MTH method further comprises the clipping of the source image 4 '. This makes it possible to better highlight the unity of meaning in the source image 4 'once it is transferred onto the tire (step shown in dashed lines DETOUR (4') in FIG. 18).
• the method further comprises a second processing (step shown in dashed lines F2 (4 ', p, Nx, L *) in FIG. 18) in which p parameters of the image source 4 'are set so that at least five percent of the gray levels Nx of said source image 4' have a brightness value L * less than 20 and at least five percent of the gray levels Nx of said source image 4 'have a brightness value L * greater than 80.
• p parameters of the image source 4 ' are in a non-limiting example the contrast and / or the brightness and / or the gamma parameter.
• the source image 4 ' is adjusted so as to obtain a marking 4 on the tire that is closest to the source image 4', notably thanks to the adjustment of the gamma parameter (also called gamma correction).
• the gamma correction can be controlled by means of a histogram of the pixel values of the source image 4 '.
• Rubbers composing tires are typically anthracite gray in color.
• the maximum amplitude of contrast on these materials is low because the maximum brightness is of the order of 25. This step thus makes it possible to maximize the contrast made on a tire for an observer, on the support that is the pneumatic with its rubber material. The loss of the maximum amplitude of contrast imposed by the material is thus minimized.
• the step of transforming the color image is performed before the second processing.
• the clipping step can be performed before or after the second treatment.
• the first treatment described previously is performed on the source image
• the MTH method further comprises an adaptation of the resolution RI of said source image 4 'as a function of the desired resolution R2 of the marking 4 on said tire 1 and the pitch Pa between two adjacent patterns in said marking 4 (step dashed ADAPT (4 ', RI, 4, R2, Pa) in Figure 18).
• the resolution RI is the number of pixels that make up the source image 4 'in height and width.
• the resolution R2 is the number of millimeters that make up the marking 4 in height and width on the tire 1, namely the space in millimeters on the tire 1 dedicated to said marking 4.
• the source image 4 'must indeed have a resolution RI adapted to the desired visual effect ultimately on the tire 1.
• the adaptation of said resolution RI according to the resolution R2 comprises the following substeps: [112] In a first substep (illustrated CALC (R2 ', R2, Pa) in FIG. calculates the resolution R2 'in pixels of a digital image corresponding to the resolution R2 in millimeters of the marking 4 to be made on the tire 1.
• a first substep illustrated CALC (R2 ', R2, Pa) in FIG. calculates the resolution R2 'in pixels of a digital image corresponding to the resolution R2 in millimeters of the marking 4 to be made on the tire 1.
• the resolution R2 ' is equal to said resolution R2 divided by said pitch Pa.
• a transcription of a physical space available on the tire 1 is carried out in a resolution of a digital image.
• the resolution RI of the source image 4' is modified.
• the resolution RI which was at the beginning of 3000 * 3000pixels is modified so as to obtain a new resolution RI equal to 100 * 100pixels.
• the gray level Nx defined by a pixel in the reduced source image 4 ' is equal to the gray level Nx defined by a square of 30 * 30 pixels in the source image 4' obtained just after the second processing in the illustrated example of Figure 18.
• FIG. 18 illustrates the MTH method of marking 4 incorporating these three additional steps (transformation of the image into color, trimming and adaptation).
• a first step 1) the source image 4 'in color is transformed into a source image 4' comprising several levels of gray Nx.
• a third step 3 the parameters of said source image 4 'are adjusted.
• the resolution RI of the source image 4 ' is adapted according to the desired resolution R2 of the marking 4 to be made on the tire 1.
• This step includes:
• the sub-epate 41 to modify the resolution RI of the source image 4 'as a function of the calculated pixel resolution R2'.
• the modification here corresponds to a decrease in the resolution RI.
• RI has been modified to define the marking 4) to obtain a target image 4 "composed of a plurality of identical basic areas 50, namely the number of gray levels Nx that one wants to obtain on the tire 1 is defined in marking 4, which amounts to defining the number of parts 500 in a base area 50.
• a sixth step 6 the laser engraving machine M is adjusted with the value of the pitch Pa between two adjacent patterns 6 to be produced, not measured on the tire 1.
• the one or more patterns 6 are selected to carry out the marking 4;
• the machine M realizes the patterns 6 in the base areas 50 so as to perform the marking 4 on the tire 1 with different levels of gray Nx.
• the laser engraving machine M only engraves one of the two levels of gray. In a non-limiting example, it engraves the black color, the white color being produced by the smooth surface of the tread and / or the side on which the marking 4 is located.
• a portion 500 is square in shape
• a plurality of patterns 6 can be produced by means of the same protruding element which is a lamella 8.
• the patterns are all adjacent to each other and aligned on the same line (horizontal or vertical) in a base zone 50.
• the openings 13 of FIG. have the circular shape, square, or polygonal (for example hexagonal) and the corresponding cavities 12 a form of cylinders, parallelepipeds, or polygons.
• the tread 2 of the tire and / or the sidewall 3 may each comprise one or more markings 4.
• a pattern 6 is achieved by simple disbursement performed by laser.
• the disbursement has a depth of between 0.1 and 0.5 mm.
• the base zones 50 may have a hexagonal shape.
• the method of performing the marking comprises: a first processing of the source image into a target image composed of a plurality of identical zones, each zone defining a level of gray among N + 1 gray levels ;
• the marking comprising a plurality of patterns.
• the method of realization further comprises a second processing in which parameters of the source image are set so that at least five percent of the gray levels of said source image have a brightness value of less than 20 and at least five percent of the gray levels of said source image have a brightness value greater than 80.
• the production method further comprises defining the pitch between two adjacent patterns to be made on the tire.
• the method of realization further comprises an adaptation of the resolution of said source image into depending on the desired resolution of said marking on said tire and the pitch between two adjacent patterns in the marking.
• the marking is carried out by laser etching by means of a laser engraving machine on a mold or directly on said tire.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Tires In General (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=51519081

Family Applications (1)

Country Status (5)

Families Citing this family (6)

Citations (1)

Family Cites Families (12)

• 2014
  • 2014-07-11 FR FR1456696A patent/FR3023507B1/fr active Active
• 2015
  • 2015-07-10 US US15/325,673 patent/US20170157994A1/en not_active Abandoned
  • 2015-07-10 EP EP15735703.9A patent/EP3166802A1/de not_active Withdrawn
  • 2015-07-10 WO PCT/EP2015/065859 patent/WO2016005569A1/fr not_active Ceased
  • 2015-07-10 CN CN201580037862.4A patent/CN106536221B/zh active Active

Patent Citations (1)

Also Published As

Similar Documents

Legal Events