JP3487894B2 - How to make wood grain conduit groove embossed plate - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing an embossed wood grain conduit groove for forming a textured wood grain pattern on an artificial decorative sheet used for wallpaper or the like.

[0002]

2. Description of the Related Art Decorative sheets such as wallpaper that express the texture of natural wood are widely used as a surface decorative material for building materials, furniture, cabinets for light electric appliances and the like. Usually, a decorative pattern imitating natural wood is printed on such a decorative sheet, and a wood grain pattern having irregularities is formed. The uneven wood grain pattern that appears on the cut surface of natural wood is a pattern that is obtained by cutting conduits that are indispensable mainly for carrying out physiological functions as plants. Will appear on the surface of. Therefore, in order to artificially express the texture of natural wood, it is important to reproduce the wood grain conduit groove existing on the surface of natural wood as faithfully as possible. For this reason, in the general manufacturing process of wallpaper and the like, an embossed plate that faithfully reproduces the wood grain conduit groove is formed, and an uneven pattern is formed on the surface of the wallpaper and the like using this embossed plate.

In order for the wood grain conduit groove formed on the wallpaper to be as visible as the natural wood grain as possible, the uneven pattern formed on the embossed plate is formed by the actual wood grain conduit groove formed in the cross section of the natural wood. It should be created based on. Therefore, usually, a method of extracting the pattern of the wood grain pattern appearing on the surface of natural wood by a method of photography and forming the extracted pattern on the embossed plate by using a photolithography method is a method. To be taken. Since the natural material is used as a motif, the uneven pattern formed on the embossed plate is close to the natural grain.

Further, as a method of faithfully reproducing the conduit groove shape of natural wood, the surface shape of natural wood board is modeled with silicone resin, etc. There is a so-called "electroforming method" in which the formed metal layer is released from the mother die.

[0005]

However, the above-described conventional method for producing a wood grain conduit groove embossing plate by the photolithography method has a problem that information on the conduit groove depth is not reflected. A natural wood grain conduit groove is a groove obtained by cutting a conduit, and usually has different depths in each portion within the groove. However, as described above, if the pattern of the wood pattern that appears on the surface of natural wood is extracted by a method such as photography, only the information on the shape of the cut of the conduit groove is extracted, and the information on the depth is It will be lost.
For this reason, the wallpaper with a textured pattern of wood grain transferred using a conventional wood grain channel embossing plate must have the depth of each channel groove almost uniform, and the texture of natural wood grain must be faithfully reproduced. Can not be. In addition, although the electroforming method faithfully reproduces the conduit groove shape of the natural wood board including the contour shape of the cut end and the gradation of the shallow depth, the number of steps and manufacturing time are large compared to photolithography, and the cost is also high. Get higher

Therefore, the present invention uses a simple photolithography method and faithfully reproduces information on the depth of natural wood grain conduit grooves so that a finish comparable to that of electroforming can be obtained. Wood grain conduit groove embossed version
The purpose is to provide a method of creating .

[0007]

[Means for Solving the Problems] (1) A first invention of the present application is a method for producing an embossed plate that reproduces an uneven structure of a wood grain conduit groove, wherein a wood grain conduit cross-sectional pattern composed of a large number of closed regions is provided. Based on the step of preparing as value image data and the information of the contour line of the wood grain conduit cross-section pattern,
The depth information of the wood grain conduit groove is defined for each position inside the closed area surrounded by the contour line, and the step of converting the binary image data into the gradation image data having the depth information as the gradation, and this gradation Based on the image data, the step of creating a negative original film in which the light transmittance becomes higher at the position where the depth information indicating that the wood grain conduit groove is deeper is defined, and the negative type resist that cures the photosensitive portion. For the membrane,
Exposure through a negative original film, transfer of the exposed resist film to the surface of the plate material that is the material of the embossing plate, and removal of the unexposed area of the resist film transferred onto the plate material by development processing And a step of causing a corrosive liquid to act on the plate material from above the remaining resist film, and performing an etching process such that the thinner part of the residual resist film has a larger corrosion depth and the thicker part has a smaller corrosion depth. , Removing the remaining resist film, and
As binary image data when defining the depth information of the pipe groove
Approximate the contour line of the prepared wood grain conduit cross-section pattern, and
Define a geometrical approximate figure that can be expressed by an expression, and
Inside a closed area surrounded by the contour of the conduit cross-section pattern
For each position of
The corresponding point whose position corresponds to
Create a geometric cross-section model of the conduit based on the method
Using the geometric cross-section model, the conduit at each corresponding point position
The depth information of the groove is obtained.

(2) A second invention of the present application is a method for producing an embossing plate that reproduces the uneven structure of a wood grain conduit groove.
For each position inside the closed area surrounded by the contour line based on the information of the contour line of the wood grain conduit cross-section pattern and the step of preparing a wood grain conduit cross-section pattern composed of a large number of closed areas Defining the depth information of the wood grain conduit groove, converting the binary image data to gradation image data having depth information as gradation, and based on this gradation image data The step of creating a positive master plate film in which the light transmittance becomes lower at the position where the depth information shown is defined, and the positive resist film that the photosensitive part elutes at the time of development are used as a material for the embossing plate. The step of forming on the surface, the step of exposing the resist film through a positive plate film, the step of removing the exposed portion of the resist film after the exposure by a developing treatment, and the remaining Etching the plate material with a corrosive liquid from above the resist film, performing a etching process such that the thinner the remaining resist film is, the larger the corrosion depth of the plate material is, and the thicker the remaining resist film is, the smaller the corrosion depth is. And when defining depth information for the wood grain conduit groove.
In addition, the cross section pattern of the wood grain conduit prepared as binary image data
Geometry that approximates the contour line of the scene and can be expressed by mathematical expressions
Define a similar approximate shape and use it as the contour line
Therefore, for each position inside the enclosed closed area, we defined
Find corresponding points that have relative positions in the approximated figure
The geometry of the conduit based on the dimensions of the defined
Create a cross-section model and use this geometric cross-section model to
To obtain the depth information of the conduit groove at each corresponding point position
It was done.

(3) A third invention of the present application is a method for producing an embossing plate which reproduces an uneven structure of a wood grain conduit groove.
For each position inside the closed area surrounded by the contour line based on the information of the contour line of the wood grain conduit cross-section pattern and the step of preparing a wood grain conduit cross-section pattern composed of a large number of closed areas The step of defining the depth information of the wood grain conduit groove and converting the binary image data into the gradation image data having the depth information as gradation, and the plate material which is the material of the embossing plate based on this gradation image data. Depth information is defined on the surface of the
The first etching treatment step to form a shallow depth inversion groove in which the shallow depth relationship is reversed with respect to the wood grain conduit groove so that it becomes shallower at the opened position , and a corrosion resistant filler is provided in the shallow depth inversion groove. A step of filling, a second etching step of causing a corrosive liquid to act from the surface of the plate material to corrode and remove a region not filled with the filler from the surface side, and a step of removing the filler,
When defining the depth information of the wood grain conduit groove,
Contour of wood grain conduit cross-section pattern prepared as image data
A geometrical approximation figure that can be approximated to a line and expressed by a mathematical formula
Defined and surrounded by the contour line of the wood grain conduit cross-section pattern
Within the defined approximate shape for each position inside the closed region
Then, the corresponding points whose relative positions correspond to
Geometric cross-section model of the conduit based on the dimensions of the approximated shape
Then, using this geometric cross-section model,
It is designed to obtain the depth information of the conduit groove in
is there.

(4) A fourth invention of the present application is a method for producing an embossing plate that reproduces an uneven structure of a wood grain conduit groove,
For each position inside the closed area surrounded by the contour line based on the information of the contour line of the wood grain conduit cross-section pattern and the step of preparing a wood grain conduit cross-section pattern composed of a large number of closed areas The depth information of the wood grain conduit groove is defined, the step of converting the binary image data into the gray scale image data having the depth information as the gray scale, and based on this gray scale image data, regarding the inside of the closed region, The light transmittance becomes higher at the position where the depth information indicating that the groove is deeper is defined, and for the outside of the closed area, a negative original film having almost the same transmittance is uniformly prepared, and For the negative type photosensitive resist film that is cured, the step of exposing through the negative original film, and the step of transferring the resist film after exposure to the surface of the plate material to be the material of the embossing plate The stage where the unexposed portion of the resist film transferred onto the plate material is removed by a development process, and the etching liquid is made to act on the plate material from above the remaining resist film, and the thinner the residual resist film is, the deeper the corrosion depth of the plate material is. A first etching process step of forming a shallow depth reversal groove in which a deeper depth relationship is reversed by performing etching such that a larger and thicker portion has a smaller corrosion depth, and a step of removing a residual resist film. The step of filling a corrosion-resistant filler in the shallow-deep inversion groove and the second step of causing a corrosive liquid to act from the surface of the plate material to corrode and remove a region not filled with the filler from the surface side When performing the etching process and the filler removal process, and defining the depth information of the wood grain conduit groove,
Of the cross-section pattern of the wood grain conduit prepared as value image data
A geometrical approximation that approximates the contour line and can be expressed by a mathematical formula
Define the shape and by the contour line of the wood grain cross section pattern
Approximation diagram defined for each position inside the enclosed closed area
Find the corresponding points in the shape whose positions correspond to each other, and
Based on the dimensions of the approximate shape you just defined,
Create a Dell and use this geometric cross-section model for each correspondence
It also tried to find the depth information of the conduit groove at the point position.
Of.

(5) A fifth invention of the present application is a method for producing an embossing plate which reproduces an uneven structure of a wood grain conduit groove,
For each position inside the closed area surrounded by the contour line based on the information of the contour line of the wood grain conduit cross-section pattern and the step of preparing a wood grain conduit cross-section pattern composed of a large number of closed areas The depth information of the wood grain conduit groove is defined, the step of converting the binary image data into the gray scale image data having the depth information as the gray scale, and based on this gray scale image data, regarding the inside of the closed region, The light transmittance becomes lower at the position where the depth information indicating that the groove is deeper is defined, and for the outside of the closed area, the step of creating a positive master film having almost the same minimum transmittance and the exposed portion. Of forming a positive type photosensitive resist film, which is eluted during development, on the surface of the plate material that is the material for the embossing plate, and exposing the resist film through the positive master plate film. And a step of removing the exposed portion of this resist film by a development process, and causing a corrosive liquid to act on the plate material from above the remaining resist film, so that the thinner the remaining resist film is, the greater the corrosion depth of the plate material is, The first etching process step of forming a shallow depth inversion groove in which the shallow depth relationship is reversed by performing etching so that the corrosion depth is reduced, a step of removing the residual resist film, and a shallow depth inversion groove. A step of filling a filler having corrosion resistance therein, and a second etching step of causing a corrosive liquid to act from the surface of the plate material to corrode and remove a region not filled with the filler from the surface side; carried out, and removing the filler, wood
Binary image data and
Approximate to the contour line of the wood grain conduit cross-section pattern prepared by
And define geometric approximate figures that can be expressed by mathematical expressions
Closed and surrounded by the contour line of the wood grain conduit cross-section pattern.
For each position inside the region , place it in the defined approximation
To find the corresponding points whose positions correspond to each other
Create a geometric cross-section model of the conduit based on the dimensions of the geometry
Then, using this geometric cross-section model,
The depth information of the conduit groove is obtained.

(6) A sixth invention of the present application is a method for producing an embossing plate which reproduces an uneven structure of a wood grain conduit groove,
For each position inside the closed area surrounded by the contour line based on the information of the contour line of the wood grain conduit cross-section pattern and the step of preparing a wood grain conduit cross-section pattern composed of a large number of closed areas Defining the depth information of the wood grain conduit groove, converting the binary image data into gradation image data having depth information as gradation, and a negative type photosensitive resist film that cures the photosensitive portion to a predetermined support. Based on the step of preparing the resist transfer film formed above and the gradation image data, the light intensity is increased so that the light intensity increases at the position where the depth information indicating that the wood grain conduit groove is deeper is defined. While modulating the beam intensity, a light beam scan is performed on the resist transfer film to expose the resist film, and after the exposure, the resist film is used as an embossing plate material. Surface, the step of removing the unexposed portion of the resist film transferred onto the plate material by a developing process, and the etching liquid acting on the plate material from the remaining resist film, and the thin portion of the residual resist film When defining the depth information of the wood grain conduit groove, the etching process is performed so that the plate material has a greater corrosion depth and the thicker part has a smaller corrosion depth, and the step of removing the residual resist film.
In addition, the cross section pattern of the wood grain conduit prepared as binary image data
Geometry that approximates the contour line of the scene and can be expressed by mathematical expressions
Define a similar approximate shape and use it as the contour line
Therefore, for each position inside the enclosed closed area, we defined
Find corresponding points that have relative positions in the approximated figure
The geometry of the conduit based on the dimensions of the defined
Create a cross-section model and use this geometric cross-section model to
To obtain the depth information of the conduit groove at each corresponding point position
It was done.

(7) A seventh invention of the present application is a method for producing an embossing plate reproducing the uneven structure of a wood grain conduit groove,
For each position inside the closed area surrounded by the contour line based on the information of the contour line of the wood grain conduit cross-section pattern and the step of preparing a wood grain conduit cross-section pattern composed of a large number of closed areas The depth information of the wood grain channel is defined, the step of converting the binary image data into the gradation image data having the depth information as the gradation, and the positive photosensitive resist film that the photosensitive portion elutes during development are embossed. Based on the step of forming on the surface of the plate material that is the material of the plate and the gradation image data, the light intensity is weakened at the position where the depth information indicating that the wood grain conduit groove is deeper is defined. While modulating the beam intensity, a light beam scan is performed on the resist film to expose the resist film, the exposed portion of the resist film is removed by a developing process, and the remaining residue is removed. The etching liquid is applied to the plate material from above the strike film, and the etching process is performed such that the thinner the residual resist film is, the larger the corrosion depth of the plate material is, and the thicker the remaining resist film is, the smaller the corrosion depth is. When defining the depth information of the wood grain conduit groove,
Cross-sectional pattern of wood grain conduit prepared as binary image data
Of the geometrical approximation of the contour line of
By defining a similar figure and
Defined approximation for each position within the enclosed enclosed area
Find corresponding points whose positions are relatively corresponding in the figure,
The geometric cross section of the conduit, based on the dimensions of the defined approximation
Create a model and use this geometric cross-section model to
The depth information of the conduit groove at the point of contact was calculated.
It is a thing.

(8) An eighth invention of the present application is a method for producing an embossing plate which reproduces an uneven structure of a wood grain conduit groove,
For each position inside the closed area surrounded by the contour line based on the information of the contour line of the wood grain conduit cross-section pattern and the step of preparing a wood grain conduit cross-section pattern composed of a large number of closed areas Defining the depth information of the wood grain conduit groove, converting the binary image data into gradation image data having depth information as gradation, and based on this gradation image data, The cutting depth becomes deeper at the position where the depth information shown is defined,
The step of cutting the surface of the plate material that is the material of the embossing plate,
When defining the depth information of the wood grain conduit groove,
Contour of wood grain conduit cross-section pattern prepared as image data
A geometrical approximation figure that can be approximated to a line and expressed by a mathematical formula
Defined and surrounded by the contour line of the wood grain conduit cross-section pattern
Within the defined approximate shape for each position inside the closed region
Then, the corresponding points whose relative positions correspond to
Geometric cross-section model of the conduit based on the dimensions of the approximated shape
Then, using this geometric cross-section model,
It is designed to obtain the depth information of the conduit groove in
is there.

[0015]

[0016]

[0017]

[0018]

[Operation] In the method for producing a wood grain conduit groove embossing plate according to the present invention, depth information is defined for each position inside the pattern based on the plane pattern of the cross section of the wood grain conduit. That is, depth information is added to each position of the wood grain conduit cross-sectional pattern prepared as binary image data, and the binary image data is converted into gradation image data having a gradation value corresponding to the depth degree. If a wood grain conduit cross-section pattern with gradation is obtained in this way, it is possible to prepare an original film having a light transmittance corresponding to this gradation, and by exposing with this original film, It is possible to form a resist film having a thickness according to the tone. When a plate material, which is a material for an embossed plate, is etched from the surface using such a resist film, the thinner the resist film is, the deeper the etching is.
That is, it is possible to form an embossed plate having an uneven structure close to that of natural wood grain.

The depth information used in the above method is calculated.
In order to do so, a geometric cross-section model of a cylindrical conduit is created based on the wood-grain conduit cross-sectional pattern input as binary image data. Generally, natural wood conduits are elongated, cylindrical tubes. Therefore, if we consider this conduit as a geometrically complete cylinder and create a model that considers the cross-sectional pattern of the wood grain conduit as a cut in which this geometrically complete cylinder is cut by a plane, we create this model as an actual natural tree. It can be applied approximately to the cross-section pattern of wood grain conduit. Since the cut end of the conduit in such a model becomes a geometrical ellipse, this geometrical model should be applied if the contour line portion of the wood grain conduit cross-sectional pattern input as binary image data is approximated by an ellipse. Will be able to. If replaced with such a geometric model, a simple arithmetic operation
The depth information of each part of the pattern can be obtained.

[0020]

The present invention will be described below based on illustrated embodiments.

§1. Natural wood grain conduit cross-section pattern An object of the present invention is to create an embossed plate having a concavo-convex pattern that is as close as possible to the natural wood grain conduit cross-section pattern. Therefore, first, the properties of the natural wood grain conduit cross-section pattern will be briefly described.

FIG. 1 shows a lumber board cut out from a very general natural wood. A fine wood grain conduit cross-section pattern often appears along the wood grain pattern appearing on the surface of such a lumber board. For example, when the circular partial area U surrounded by a small circle in FIG. 1 is enlarged, it is understood that a set of elliptical patterns P as shown in FIG. 2 constitutes a wood grain pattern. Such an elliptical pattern P is a wood grain conduit cross-section pattern, that is, a pattern obtained as a cross section of a conduit existing in natural wood. This wood grain conduit cross-section pattern becomes a long and narrow elliptical pattern,
Let's use the model in Figure 3. Here, the description will be given assuming that the conduit T existing in the natural wood has a perfect cylindrical shape. The conduit T is a pipe used as a flow path for substances required for the life support of the plant, and extends along the growth direction of the plant. That is, in the case of a natural tree, it extends in the direction along the trunk. When a lumber board is cut out from such a natural wood, it is usually cut in the direction along the trunk so that a board having a wider area can be taken. Therefore, the longitudinal axis of the conduit T and the cut surface C generally form an acute angle, as shown in FIG. Therefore, the cut end of the conduit T appearing on the cut surface C, that is, the cross-sectional pattern of the wood-grain conduit becomes an elongated elliptical pattern P as shown in the upper part of FIG.

By the way, each of the plurality of elliptical patterns P shown in FIG. 2 is an elongated ellipse substantially along the direction of the longitudinal direction L. This is because all the conduits T existing inside the natural tree extend toward the growth direction of the tree, and thus the directions of the adjacent elliptical patterns P are almost the same. Therefore, also in the whole timber board as shown in FIG. 1, the longitudinal direction L (in the case of this example, the direction extending to the left and right in the figure) that is substantially common to the many elliptical patterns existing on the surface can be determined.

Now, such an elliptical wood grain conduit cross-sectional pattern is only a cross-sectional pattern appearing on the cut surface C, and is merely the shape of the cut portion of the actual wood grain conduit groove. The actual wood grain conduit groove formed in the surface portion of the timber board is a groove with a deep depth. Therefore, let us examine what kind of distribution the depth of this conduit groove will have. Now consider three cross-sections C1, C2, C3 of the conduit T in the model shown in FIG. Three ellipses C1, C2 and C3 shown in the lower part of FIG. 3 are cross-sectional views at respective cross-section positions. Here, the horizontal broken line C indicates the position of the cutting plane C, and the hatched portion below it indicates the cutting plane C.
2 shows the inner region of the conduit groove G formed in the timber board obtained below. As is clear from this model, the actual depth of the conduit groove G is shallowest on the right side of the figure and deepest on the left side of the figure. Moreover, from right to left,
The depth gradually increases, and the depth increases monotonically from right to left. Further, the depth distribution of the elliptical pattern P in the minor axis direction has an arc shape.

Therefore, although the elliptical pattern P shown in the upper part of FIG. 3 is a mere planar cross-section pattern, if depth information is added to this planar pattern, the right side of the figure is the shallowest, The left side of is deepest. In addition, as described above, since the many adjacent conduits T extend in substantially the same direction, the distribution relationship of the depths is also the same. For example, for one of the plurality of elliptical patterns P shown in FIG. 2, if depth distribution information that the right side edge is shallow and the left side edge is deep is obtained,
Such depth distribution information can be commonly applied to all other elliptical patterns P. If the field of view is further expanded, such depth distribution information can be commonly applied to all of the large number of elliptical patterns formed on the timber board shown in FIG. It should be noted that in a special case where the orientation of the grain changes in the middle, the same depth distribution information cannot always be applied in common,
For most natural wood, such an application does not pose a problem.

In the above model, the conduit T is treated as a simple cylindrical shape, but it is rare that the actual conduit has a geometrically perfect cylindrical shape, and it is natural. Therefore, it naturally has an irregular shape. Some of them are closer to a conical shape that gently slopes from the root to the treetop, rather than a cylindrical shape (cylindrical shape). Therefore, the actual wood grain conduit cross-section pattern has a somewhat distorted shape rather than a geometrically perfect ellipse.

§2. Conventional wood grain conduit groove embossed plate The conventional general method of creating a wood grain conduit groove embossed plate is to extract the pattern of the wood grain pattern appearing on the surface of natural wood by a method such as photography, and extract this extracted pattern. It is a method of forming on the embossed plate by using a photolithography technique. However, in this way,
Since the concavo-convex pattern is formed on the embossing plate only by the information on the cross-sectional pattern of the wood grain conduit appearing on the surface of the natural wood, the information on the depth of the conduit groove cannot be reproduced. FIG. 4 is a cross-sectional view showing an example in which a concavo-convex structure is formed on the embossing plate E using the planar elliptical pattern P. The convex portion formed on the embossing plate E has an elliptical pattern P in a plan view, but the height thereof is substantially uniform (actually, the corner portion is slightly a little based on the characteristics of the etching process. It is rounded) and has a monotonous raised structure.

Using such a conventional embossing plate E,
Wood grain print S (for example, vinyl chloride sheet)
When the concavo-convex structure is transferred to (for example, the embossing plate E is pressed against the vinyl chloride sheet while applying heat), as shown in FIG. 5, a concave part having an elliptical pattern P in plan view is formed. However, the depth is almost uniform (actually, as described above, the corners are slightly rounded), forming a monotonous groove structure. Usually, ink is applied to the inner surface of the recess, but when observing the surface of such a wood grain print S, there is no depth distribution in the formed recess, and therefore the actual natural wood Compared with the case of observing the conduit groove of, the texture will be slightly different,
A feeling of strangeness that is slightly different from that of natural wood will remain.

Therefore, instead of the convex portion of the embossed plate E as shown in FIG. 4, an embossed plate E'having an inclined convex portion as shown in FIG. 6 is prepared. The height of the convex portion is lowest at the right end of the figure, gradually increases toward the left, and becomes highest at the left end of the figure. When the embossed plate E ′ is used to transfer the concavo-convex structure to the wood grain print S ′, a recess having a depth distribution is formed as shown in FIG. 7. That is, the depth of the recess is shallowest at the right end of the figure, gradually deepens toward the left, and deepest at the left end of the figure. Such a depth distribution matches the model of the natural tree shown in FIG. Similarly, in the direction of the minor axis of the ellipse as well, the shape is rounded to match the natural wood. That is, the recesses formed on the wood grain print S ′ shown in FIG. 7 have a depth distribution that matches the conduit grooves of natural wood, and a natural texture can be obtained when observed.

An object of the present invention is to provide a convex portion having a height distribution as shown in FIG. 6 so that a concave portion having a depth distribution as shown in FIG. 7 can be embossed on a wood pattern print. It is to provide a way to create an embossed version.

§3. Method Using Negative Gradation Image Hereinafter, an example of a method for producing a wood grain conduit groove embossing plate according to the present invention will be described. Here, first, an embodiment using a negative gradation image will be described. Now, consider a gradation image as shown in FIG. This gradation image shows a wood grain conduit groove having a depth distribution corresponding to the concave portion of the wood pattern print S ′ shown in FIG. 7. As shown in FIG. 8 (b), the deeper the groove is, the higher the floor is. The light transmittance of the toned image is high (that is, the density value is small). In other words, the deepest part of the groove is represented by “white”, and the shallowest part and the outside of the groove are represented by “black”. This black-and-white relationship is the reverse of the general feeling that "black" is deep inside the groove and "white" at the shallow part of the groove, so in this specification, such a gradation image is referred to as "negative ( Negative image) ”gradation image.

The representation of the gradation image of the wood grain conduit groove in the drawings of the present application shows only the one-dimensional density distribution in the longitudinal direction of the groove, but this is for convenience of illustration. , In fact, a two-dimensional light and shade distribution on a plane is obtained. For example, in the gradation image shown in FIG. 8A, the gradation distribution in the groove is shown as a gradation distribution in the horizontal direction of the figure. It depends. The actual wood grain conduit groove G has a depth distribution also in the direction orthogonal to the longitudinal direction, as shown by hatching in the sectional views C1, C2, and C3 shown in the lower part of FIG. If such an actual depth distribution is shown as a gradation in the drawing, the illustration becomes complicated. Therefore, in the drawing of the present application, only the gradation in the longitudinal direction of the wood grain conduit groove will be shown.

By the way, it is very difficult to obtain such a gradation image from the pattern of the grain pattern appearing on the surface of natural wood by a photographing method or the like. §2
As described in Section 1, the methods such as ordinary photography cannot extract information about the depth of the conduit groove, and a binary image (for example, the inside is Only "black" and "white" outside can be extracted). A major feature of the present invention is that such a binary image is converted into a gradation image as shown in FIG. 8 (a) by calculation. This operation is actually performed by a computer. For example, a binary image is obtained from a wood grain pattern appearing on the surface of natural wood by a photography method or the like, and then this binary image is captured as digital data by an input scanner device or the like. Then, based on the information of the elliptical contour line of the captured pattern, depth information is defined for each position inside the closed area surrounded by the contour line, and a gradation image having this depth information as gradation Create the data. A specific method of creating such gradation image data will be described in detail in Section 6 described later.

Now, the following description will be continued assuming that a gradation image as shown in FIG. 8A has been prepared.
As described above, this gradation image is created as digital data in the computer. However, if a continuous output scanner device or the like is used, the gradation image thus created can be output on a film. it can. here,
In this way, the film on which the negative gradation image is output is
I will call it the negative original film. The light transmittance T (transmitted light intensity / incident light intensity) of this negative original film and the density value D of the image have a relationship of D = log (1 / T), and thus are shown in FIG. 8 (c). Like That is, the light transmittance is higher at a position where depth information indicating that the wood grain conduit groove is deeper is defined.

Then, as shown in FIG. 9 (cross-sectional view), the negative photosensitive resist 2 is formed on the support film 10.
A resist transfer film 100 formed by forming 0 in a film shape is prepared. As the support film 10, a balatay paper used in so-called "carbon tissue" or a resin film such as polyethylene terephthalate used in so-called "auto film" may be used.
The negative photosensitive resist 20 is a resist having a property that the photosensitive portion is hardened, and is composed of dichromated gelatin,
Acrylic ester monomers or prepolypolymers having an acrylic group or a methacrylic group in the molecule, a mixture of bisazide and diene rubber, polyvinyl cinnamate compounds and the like can be used, but in this example, as a preferred material Dichromated gelatin is used. The negative original film 30 is placed on the resist transfer film 100 as shown in FIG. As described above, the negative original film 30 has a gradation pattern as shown in FIG. 8A when viewed from above.

Next, as shown in FIG. 10, ultraviolet rays or visible rays are irradiated through the negative original film 30 (a carbon arc lamp, a mercury lamp or the like may be used as a light source), and the negative resist 20 is exposed. I do. Dichromated gelatin has an exposure density (light intensity I ×
When the exposure time t) exceeds a predetermined set value, it is a negative type resist having a property that a chemical reaction (crosslinking reaction, polymerization reaction) due to exposure abruptly proceeds to cure. Therefore, if the area where the exposure amount density exceeds this predetermined set value is called the exposed area and the other area is called the unexposed area, the resist of the exposed area is in a cured state and the unexposed area is not exposed. The resist remains in its original state (a state in which it is eluted by the subsequent development processing). Therefore, in the negative resist 20 after exposure, the photosensitive portions 21 and the unexposed portions 22 are distributed as shown in FIG. It can be seen that the hatched portion in the drawing is the photosensitive portion 21, and the deeper the portion of the negative original film 30 is, the higher the light transmittance is.

Then, a resist film is transferred onto the surface of the plate material which is the material for the embossing plate. That is, in the state shown in FIG. 10, the negative original film 30 is removed,
The upper surface of the resist transfer film 100 after exposure is covered with the plate material 40.
Closely pressurize the surface of. At this time, if moisture is given to the resist, the gelatinous substance contained in the unexposed portion 22 flows out to the interface with the plate material 40, and the adhesiveness of the gelatinous substance causes the photosensitive portion 21 to move to the surface of the plate material. (In this specification, the operation of attaching the resist film to the surface of the plate material as described above is referred to as “transfer”). This transfer step can be performed by using the ordinary gravure platemaking method as it is. In this embodiment, a copper flat plate is used as the plate material 40, but an iron plate or a cylindrical plate material can also be used. After all, this transfer step is an operation in which the resist transfer film 100 shown in FIG. 10 is turned upside down and attached onto the plate material 40. If development is performed in this state, the unexposed portion 22 is eluted into the developer and removed, and the support film 10 is in a peeled state. This developing process is performed by immersing the plate material 40 and the resist transfer film 100 in a hot water pad at 35 to 45 ° C. Thus, as shown in FIG.
Only the photosensitive portion 21 of the resist film remains on the surface of the.

Next, the remaining resist film (photosensitive portion 2
1) A corrosive liquid is caused to act on the plate material 40 from above, and an etching process is performed such that a thinner portion of the residual resist film has a larger corrosion depth and a thicker portion has a smaller corrosion depth.
This etching process can also use the method of usual gravure plate making. The corrosive liquid is appropriately selected depending on the material of the resist and the plate material. When dichromated gelatin is used as the resist and copper or iron is used as the plate material, a ferric chloride solution is used as the corrosive liquid. Is preferred. After such etching treatment, if the residual resist film is removed, an embossed plate 41 having a sectional structure as shown in FIG. 12 is obtained. That is, the thinner the residual resist film is, the deeper it is corroded. This is because it takes time for the corrosive liquid to reach the surface of the plate material in the thick region of the resist film, so that the corrosion time becomes shorter than that in the thin region of the resist film. In practice, it is preferable that several ferric chloride solutions having different Baume degrees are made to act in the descending order of the Baume degree in accordance with ordinary gravure plate making.

The structure of the embossing plate 41 shown in FIG. 12 thus obtained corresponds to the ideal structure shown in FIG.
Therefore, by forming a wood grain conduit groove on a wallpaper or the like using such an embossed plate, a groove having a depth distribution close to that of a natural conduit groove can be obtained.

In the above embodiment, for convenience, the case where the concavo-convex structure for a single wood conduit groove is formed is described, but in reality, the concavo-convex structure for a large number of wood conduit grooves is simultaneously formed. It will be.

§4. Method Using Positive Gradation Image Next, an example using a positive gradation image will be described. First, a gradation image as shown in FIG. 13 (a) is prepared. This gradation image is a gradation image in which the black-and-white relationship is reversed with respect to the negative gradation image shown in FIG. This black and white relationship is
In the present specification, such a gradation image is referred to as a “positive (positive image)” gradation image, because the depth of the groove is “black” and the shallow part of the groove is “white”. I will call it. When such a positive gradation image is prepared, it is output on a film to prepare a positive original film. The density value distribution of this positive original film is as shown in FIG. 13 (b), and the light transmittance is as shown in FIG. 13 (c).

Subsequently, as shown in FIG. 14 (cross-sectional view), a positive type photosensitive resist 60 is formed on the plate material 50 (for example, a metal plate such as copper or iron). here,
The positive type photosensitive resist 60 is a resist having a property that a photosensitive portion is eluted by development and only an unexposed portion remains, and a phenol resin type resin or a novolac resin type is known. A resin sensitized with benzoquinone azide ester is used. On the positive type resist 60, the positive original film 7
Put 0. As described above, this positive original film 7
At 0, a gradation pattern as shown in FIG. 13A is drawn when viewed from above.

Next, as shown in FIG. 15, the positive resist 70 is exposed through the positive master film 70. As a result, the resist 60 is divided into a photosensitive portion 61 and a non-photosensitive portion 62, as shown in FIG. The hatched portion is the photosensitive portion 61,
The higher the light transmittance of the positive original film 70, the deeper the area is exposed.

Subsequently, if the exposed resist is developed,
The photosensitive portion 61 is dissolved in the developing solution and removed, and as shown in FIG.
Only will be left. The uneven structure of the residual resist film 62 shown in FIG. 16 corresponds to the residual resist film 21 shown in FIG.
It is almost the same as the uneven structure of. Therefore, as in the embodiment of §3, the corrosive liquid is caused to act on the plate material 50 from above the remaining resist film 62, and the thinner the residual resist film is, the larger the corrosion depth of the plate material is. If the etching process is made smaller, the embossed plate 41 having a cross-sectional structure as shown in FIG. 12 can be obtained.

§5. Method of etching twice (part
1) Next, a method of performing the etching process on the plate material in two steps will be described. First, examples using a negative original film will be described. In this embodiment, a gradation image as shown in FIG. 17 (a) is prepared. This gradation image is exactly the same as the negative gradation image shown in Fig. 8 (a) for the inside of the elliptical closed region, but for the outside of the closed region, the density value is 0. It is a toned image. That is,
For the inside of the conduit closed area, the light transmittance is higher at the position where the depth information indicating that the wood grain conduit groove is deeper is defined, and for the outside of the conduit closed area, it is uniformly the maximum or near the maximum light transmittance. It is an image with. Therefore, the density value distribution is as shown in FIG. 17 (b), and the light transmittance distribution is as shown in FIG. 17 (c). Since such a gradation image is basically a gradation image having a negative property, it is tentatively called a "negative gradation image" here.

The processing in the first half of this method is the same as in the embodiment described in §3. That is, as shown in FIG. 18 (cross-sectional view), a resist transfer film 100 formed by forming a negative photosensitive resist 20 in a film shape on a support film 10.
Is prepared, and a negative original film 31 having a gradation image as shown in FIG. 17 (a) is placed thereon. And FIG.
As shown in FIG. 9, the negative resist 20 is exposed by irradiating ultraviolet rays or visible rays through the negative original film 31. By this exposure, the exposed portion 23 and the unexposed portion 24 are formed.

Subsequently, a plate material 80 which is a material for the embossing plate
The resist film is transferred to the surface of the. That is, the resist transfer film 100 shown in FIG.
Paste it on 0. If development is performed in this state, the unexposed portion 24 is eluted and removed in the developing solution, and the support film 1 is removed.
0 is in a peeled state, and only the photosensitive portion 23 of the resist film remains on the surface of the plate material 80 as shown in FIG.

Next, the remaining resist film (photosensitive portion 2
3) A corrosive liquid is caused to act on the plate material 80 from above, and the first etching process is performed such that the thinner the residual resist film is, the larger the corrosion depth of the plate material is, and the thicker the remaining resist film is, the smaller the corrosion depth is. As a result, the plate material 80 is processed into the intermediate body 81 having the structure shown in FIG. A groove is formed on the surface of the intermediate body 81. Since this groove is a groove having a shallow depth relationship reversed from that of the original wood grain conduit groove, here, it is referred to as a shallow depth inversion groove 82. I will call it. The difference between the intermediate body 81 shown in FIG. 21 and the structure shown in FIG. 12 is that
The outside of the closed region of the conduit is not etched and the original height is maintained.

Then, as shown in FIG. 22, an auxiliary film 83 is formed on the surface of the intermediate body 81 as needed, and further, as shown in FIG. The agent 84 is filled. Here, as the filler 84, a material having corrosion resistance to the corrosive liquid used in the second etching process performed next is used. Thus, when the second etching process is performed, the filler 84 functions as a mask, the region not covered with the mask is corroded, and the intermediate 81 is transformed into the structure 85 as shown in FIG. After that, if the auxiliary film 83 and the filler 84 are removed, the structure 85 becomes the embossing plate 85 as it is, as shown in FIG. The structure of the embossing plate 85 shown in FIG. 25 thus obtained corresponds to the ideal structure shown in FIG.

In this embodiment, a plate of copper is used as the plate material 80, and a ferric chloride aqueous solution is used as a corrosive liquid in the first etching and the second etching.
Therefore, any material may be used as the filler 84 as long as it is a material having corrosion resistance to this corrosive liquid. In this embodiment, printing ink (offset ink) is used as the filler 84. It was used (the same process can be performed by using a room temperature curable resin instead of the printing ink). A general printing ink has a viscosity suitable for filling a fine groove, and the step of filling the shallow depth inversion groove 82 can be easily performed. In other words, the method of applying ink to the printing plate surface can be used as it is. Specifically, the filling is completed by applying a printing ink diluted with a solvent to the entire upper surface of the intermediate body 81 and scraping off the excess ink with a squeegee or a doctor blade. Moreover, since the printing ink can be hardened by natural drying, the process of hardening in the shallow depth inversion groove 82 after coating and filling can also be performed by the natural drying method, and the work efficiency is very good.
That is, if left at room temperature for about 24 hours after filling, it can be sufficiently dried and cured. After that, if the ink hardened and adhered to the outside of the groove is polished and removed with a grindstone, the ink can be left only inside the groove. The auxiliary film 83 is formed for the purpose of improving the filling property of the filler 84, and is not always necessary. However, when a printing ink is used as the filler 84, it is preferable to form a chromium plating film as the auxiliary film 83. The chromium film has an interfacial property that improves the filling property of the printing ink, and the so-called “ink deposit” is improved on the chromium film.

When the time of the second etching in the above-mentioned step becomes long, the corrosive liquid gradually begins to permeate into the region masked by the filler 84, and the convex tops of the finally obtained embossed plate 85 corrode. It may be flattened. In such a case, if the third etching in which the corrosive liquid is sprayed from above the convex top is performed, the corners formed in the contour portion of the flattened area are quickly corroded,
An overall smooth ridge structure can be obtained.

As described above, the feature of this embodiment is that only the inside of the conduit closed region is etched by the first etching and the outside of the conduit closed region is etched by the second etching. As described above, an advantage of the method of performing the etching twice is that the resist film in the conduit closed region can be prevented from being peeled off during the etching. For example, in the method described in §3, as shown in FIG. 11, etching is performed in a state in which the plate material 40 is covered with the convex resist film 21, but in this case, the flow of the etching solution is the resist. The resist film 21 may be peeled off during etching because it directly collides with the convex portion of the film 21 corresponding to the closed region of the conduit. On the other hand, in the method of this embodiment, at the time of the first etching, as shown in FIG. 20, the etching is performed with the plate material 80 covered with the concave resist film 23. There is almost no possibility that the resist film will peel off due to the flow.

§6. Method of etching twice (part
2) The above-mentioned examples are examples using the negative original film 31, but the same method can be performed using a positive original film. That is, instead of the negative tone image shown in FIG. 17 (a), a positive original film having a positive tone image in which the gradation relationship is reversed is used.
In other words, in the positive gradation image, the light transmittance becomes lower at the position where the depth information indicating that the wood grain conduit groove is deeper is defined, inside the conduit closed region, and outside the conduit closed region. It can be said that the image has a uniform or minimum transmittance.

As described above, when the positive original film is used, it is not necessary to prepare the resist transfer film.
A positive type photosensitive resist film is directly formed on the upper surface of the plate material 80, and the positive type resist is exposed through a positive original plate film. After that, when development is performed, in the positive resist, the photosensitive portion is eluted, so that the same structure as that shown in FIG. 20 is eventually obtained. The following steps are exactly the same as the method described in §5.

§7. Method without using the original film In all of the examples described so far, a positive or negative original film is prepared, and the resist film is exposed through this original film, and the plate material is etched. It is also possible to form an uneven pattern on the plate material without using a film at all. Below, several methods are described.

The first method is a method of exposing the resist in the method described in §3 or §5 by light beam scanning. For example, in the method described in §3, the negative original film 30 as shown in FIG. 8 (a) was used and the resist transfer film 100 was exposed as shown in FIG. 9, but the same effect as this exposure was obtained. Is realized by light beam scanning. That is, the negative original film 30 was used by performing scanning while directly irradiating the upper surface of the negative resist 20 of the resist transfer film 100 with the light beam without using the negative original film 30 and modulating the light beam intensity. The exposure state is the same as in the case. Specifically, the light beam may be modulated so that the intensity of light becomes stronger at a position where depth information indicating that the wood grain conduit groove is deeper is defined. When performing scanning with this light beam, it is preferable that the film is closely attached to a flat plate or a cylinder so that the resist transfer film 100 is not bent, and scanning is performed in a fixed state. After the exposure state as shown in FIG. 10 is obtained, the steps are exactly the same as those of the method described in Section 3 above. Also in the method of §5, exposure by light beam scanning is possible similarly.

The second method is a method of exposing the resist in the method described in §4 or §6 by light beam scanning. For example, in the method described in §4, exposure is performed using a positive master film 70 as shown in FIG. 13 (a), but this exposure is performed by light beam irradiation without using the positive master film. . In this case, the light beam may be modulated so that the intensity of the light becomes weaker at a position where depth information indicating that the wood grain conduit groove is deeper is defined. Other steps are exactly the same as the method described in §4. Also in the method of §6, exposure by light beam scanning is possible in the same manner.

The third method is a method of directly cutting the plate material instead of etching. For example, Japanese Patent Publication Sho 62-
Japanese Patent Publication No. 45978, Japanese Patent Publication No. 62-45982 and the like disclose an electronic engraving machine used for electronic engraving of a gravure plate. In such an electronic engraving machine, the plate material is cut by linearly feeding a cutting blade such as a diamond needle in the axial direction while rotating a cylinder serving as a plate material around an axis. By controlling the cutting blade according to the instruction of the computer, it is possible to form a desired concave-convex pattern on the surface of the plate material while spirally scanning the cylindrical plate material. By using such an electronic engraving machine, the conduit groove pattern can be directly formed on the surface of the plate material without performing etching. That is, based on the depth information of the wood grain conduit groove, the surface of the plate material that is the material of the embossing plate is cut so that the cutting depth becomes deeper at the position where the depth information indicating that the wood grain conduit groove is shallower is defined. The electronic engraving machine may be controlled as described above. In addition, in order to perform cutting, not only mechanical cutting using a blade but also non-contact cutting using a laser light beam such as a high-power carbon dioxide gas laser or an energy beam such as an electron beam I don't care.

§8. The method described in §3~§6 described above the principles of the depth information calculating wood grain conduit grooves are all the information about the depth of the wood vessel grooves prepared gradation image is replaced with information on the concentration, like this This is a method of performing a photolithography process using an original film on which a gradation image is drawn. Further, the above-mentioned method of §7 is a method of performing light beam scanning and cutting based on such a gradation image. One of the features of the present invention is that such a gradation image is obtained by calculation. As already mentioned, when the pattern of the wood grain conduit groove is extracted from the wood grain pattern appearing on the surface of natural wood by a method such as photography, it is not possible to extract information on the depth of the conduit groove, and the ellipse Only a binary image (for example, an image in which the inside is “black” and the outside is “white”) that can distinguish the inside and the outside of the pattern is extracted. In other words, it is only possible to obtain information on the planar contour. The depth information calculation described here is a calculation for giving depth information to each position of the closed region surrounded by such a contour.

First, in order to explain the principle of this operation method, consider a geometric model as shown in FIG. This model is the same as the model shown in FIG. 3, and is a three-dimensional model that is based on the assumption that the conduit T has a perfect geometric cylindrical shape. In such a model, the cross section of the conduit T at the cutting plane C becomes a geometrically correct ellipse J. When the diameter of the conduit T is D, the length of the major axis of the ellipse J is V, the length of the minor axis is W, and the angle formed by the axial direction of the conduit T with respect to the cutting plane C is θ, Let's examine the relationship between each of these numbers. Then, geometrically, the relation W = D V = D / sin θ holds. This is because if the ellipse J that is the cross-sectional pattern is specified (that is, if the length V of the long axis and the length W of the short axis are specified), the diameter D of the conduit T is also cut.
It also indicates that the angle θ with respect to is also specified. In other words, given an arbitrary ellipse,
It follows that a geometric model of the conduit T and the section C where such an ellipse appears as a cross-sectional pattern is determined. However, since information about which of the conduit grooves is deep cannot be obtained only from the ellipse information, strictly speaking, by giving the distribution information of the groove depth, the only geometric model is determined. It will be. For example, in Figure 2.
In FIG. 6, if the ellipse J is given and the depth distribution information that the position of the point F1 is the deepest and the position of the point F2 is the shallowest is given, the three-dimensional model as shown in this figure is uniquely determined. It will be. On the contrary, when the depth distribution information that the position of the point F1 is the shallowest and the position of the point F2 is the deepest is given, even if the model has the same ellipse J as the sectional pattern, the direction of the conduit T is reversed. Becomes a three-dimensional model.

XYZ with the cutting plane C taken on the XY plane
Consider a three-dimensional coordinate system. At this time, if the center point O of the ellipse J is the origin of the coordinate system, the ellipse J becomes a plane figure on the XY plane, and the depth of the conduit groove corresponds to the Z coordinate value. For example, arbitrary points Q1, Q2 on the surface of the conduit T
When projected onto the XY plane, the points Q1 and Q2 are projected at the positions shown in the ellipse J of FIG. 26, but these points are actually located on the XY plane. Depth z1,
It is the point at the position of z2. This is clearly shown in the sectional view below. However, if the diameter D of the conduit T and the intersection angle θ with the XY plane are determined, the points Q1 and Q2
The values z1 and z2 indicating the depth of can be calculated. In other words, an arbitrary projection point Q within the ellipse J
A specific value z indicating the depth can be calculated for (x, y). Specifically, z = ((r ² −x ² ) ^½ −y · sin θ) / co
The value z can be obtained by the formula sθ. However, r = D / 2 (radius of the conduit T) x ² + z ² · sin ² θ ≦ r ² .

From the above description, the following can be understood. Suppose that all actual natural wood conduits have a geometrically perfect cylindrical shape, and such natural wood is cut in a perfect plane to obtain a lumber board. In this case, the cross section pattern of the wood grain conduit appearing on the surface of this timber board is a geometrically complete ellipse, and the depth of each part of the wood grain conduit groove can be calculated by calculation based only on the information of this cross section pattern. . For example, suppose that a wood grain conduit cross-section pattern as shown in FIG. 2 is obtained from a lumber board as shown in FIG. This pattern is a number of ellipses oriented in the longitudinal direction L and does not contain information about the depth of the conduit groove. However, by observing each conduit groove formed on the actual timber board and obtaining which of the left and right directions along the longitudinal direction L the groove is deep, the above-mentioned method is used. , It becomes possible to define depth information at each position inside each ellipse pattern. By converting such depth information into density values, a gradation image as shown in FIG. 8 (a) can be obtained. In the present invention, the binary image of the wood grain conduit cross-sectional pattern is converted into the gradation image by such a method.

[0063]§9. Actual depth information calculation By the way, unfortunately the above geometric model
It cannot be applied as is to the conduit of Karaki. Actual
The conduit of natural wood has a roughly cylindrical shape.
However, strictly speaking, it is a distorted shape that is not a geometrical cylinder
Are doing Therefore, the actual wood grain conduit cross section
The pattern should be a slightly distorted shape, not an exact ellipse.
You are doing it. So, in reality,
Take a method to fit the above model by defining a similar ellipse
It will be.

FIG. 27A shows a geometrically complete ellipse J.
Is shown, and a somewhat distorted figure K is shown in FIG. Actually, the ellipse J is an ellipse obtained as an approximate ellipse of the figure K. The method of obtaining such an approximate ellipse is relatively simple. First, the length h of the figure K in the longitudinal direction is obtained. To determine the longitudinal direction of the figure K, for example, while rotating the figure K on the XY plane, search for a direction in which the distance between the point A having the largest Y coordinate value and the point B having the smallest Y coordinate value becomes the largest. The Y-axis direction in that direction is the longitudinal direction. The distance between the points AB at that time is the length h in the longitudinal direction. Alternatively, in the case of ordinary natural wood, the longitudinal direction of many conduit groove cross-sectional patterns is almost common, so when inputting the pattern of natural wood from a scanner device, etc., the operator should indicate the longitudinal direction. May be. In this case, the longitudinal direction of each pattern is slightly deviated from the common longitudinal direction, but this is not a practical problem. Next, the maximum value of the width in the direction orthogonal to the longitudinal direction is obtained. In the case of the figure K shown in FIG. 27 (b), the maximum value of this width is 2r. Therefore, if an ellipse J having a major axis length h and a minor axis length 2r is defined, this ellipse J becomes an approximate ellipse.

As another method of obtaining the approximate ellipse, instead of taking the maximum value of the width as the length of the minor axis, the width at the midpoint in the longitudinal direction can be taken. That is, when the length h in the longitudinal direction is obtained, the width of the figure K at the position of the length h / 2 (width in the direction orthogonal to the longitudinal direction) is obtained and used as the length of the minor axis. In addition, the approximate ellipse may be obtained by any method. Since this approximate ellipse is a graphic used for the purpose of calculating the depth information, even if the degree of approximation is somewhat low, it does not pose a serious problem in practice.

Now, when the approximate ellipse is obtained, the corresponding point is found in the approximate ellipse J for any point in the figure K. Here, the corresponding points are points at relatively corresponding positions. For example, 1 in the figure K in FIG. 27 (b).
For the point P1, the corresponding point Q1 within the ellipse J of FIG. 27 (a) is found. Here, the point P1 and its corresponding point Q1 have the following relationship. That is, the distribution position of the points P1 in the longitudinal direction of the figure K is equal to the distribution position of the corresponding points Q1 in the major axis direction of the ellipse J, and the distribution position of the points P1 in the direction orthogonal to the longitudinal direction of the figure K. And the distribution position of the points Q1 in the minor axis direction of the ellipse J become equal. Let me show this more concretely. First, regarding the position in the vertical direction in the figure, if the point P1 is located at a position dividing the longitudinal direction of the figure K into a: b, the point Q1 is located at a position dividing the major axis of the ellipse J into a: b. It must be a point of existence. Regarding the horizontal position in the figure, if the point P1 is located at a position that divides the horizontal width of the figure K into c: d, the point Q1 also divides the horizontal width of the ellipse J into c: d. It must be a point that exists at the position where Corresponding points that satisfy such conditions can be obtained by simple coordinate calculation.

By the way, an ellipse J as shown in FIG.
Is a geometrically correct ellipse, it is possible to apply the geometric model described in §8. That is, for any point Q1 (x, y) in this ellipse J,
The depth value z can be calculated. Therefore, if the depth value z obtained for the corresponding point Q1 is defined as it is as the depth value for the original point P1 in the figure K, then for any point in the figure K,
Each predetermined depth value can be defined by calculation. According to the present invention, the geometric model described in §8 is applied to the distorted wood grain conduit groove cross-sectional pattern by such a method, and the wood grain conduit groove cross-sectional pattern obtained from an actual natural tree is applied. Depth information is given to.

Next, an example of the configuration of a specific device for performing the above-mentioned depth information calculation will be shown. FIG. 28 is a block diagram showing a configuration example of such an arithmetic unit. This apparatus uses a pattern input means 1 for inputting a cross-sectional pattern of a wood grain conduit as shown in FIG. 2 as digital image data, an approximate ellipse defining means 2 for defining an ellipse approximating the contour line of this pattern, and this contour line. For each position inside the enclosed closed region, a corresponding point calculation means 3 for finding a corresponding point whose position relatively corresponds in the approximate ellipse, and a cylindrical shape based on the lengths of the major axis and the minor axis of the approximate ellipse. Create a geometric cross-section model of the conduit, and in this geometric cross-section model,
Depth information calculation means 4 for calculating depth information of the conduit groove at each corresponding point position obtained by the corresponding point calculation means 3.
And, Here, the pattern input means 1 is an image input means such as a scanner device, and the approximate ellipse definition means 2, the corresponding point calculation means 3, and the depth information calculation means 4 are means realized by a computer. Since the image data is handled on a pixel-by-pixel basis inside the computer, the corresponding point calculation means 3 carries out a calculation for obtaining corresponding points on a pixel-by-pixel basis. In this case, for example, the center point of the pixel may be treated as the representative position of the pixel. Finally, if the depth value calculated by the depth information calculation means 4 is output as a density value on the film, an original film having a gradation image can be created. When applied to the embodiment described in §7,
Based on the depth value calculated by the depth information calculation means 4, the light beam intensity can be modulated and the engraving machine can be controlled.

§10. Separation process of cross-sectional pattern of wood grain conduit
Management up to now, grain conduit cross-section pattern obtained by such methods from the natural wood photography has been promoting a story based on the assumption that the shape close to a generally elliptical. Certainly, when one conduit is cut, the cut end has a substantially elliptical shape. However, in natural wood, there is a part where two conduits are fused, and as for such a part, as shown in FIG. 29, the cut end seems to be a fusion of two elliptical patterns. It has a complicated shape. In addition, even if two trees are not fused in actual natural wood, if the two wood grain conduit cross-section patterns are very close to each other, they will be fused at the stage of performing optical processing such as photography. Sometimes it ends up. When the depth calculation processing described above is performed on such a fused pattern, correct processing will not be performed unless the fused pattern is separated into two. For example, in the case of the pattern as shown in FIG.
Although it can be recognized that the two elliptical patterns are fused, a uniform processing by a computer requires an approximate ellipse for the entire fused pattern. Therefore, it is preferable to find such a fusion pattern and perform the separation process by the following method before the depth calculation process.

First, the process of scanning the pattern shown in FIG. 29 in the horizontal direction will be sequentially performed from the top to the bottom. Then, in the portion above the line A, two sets of horizontal line segments a1 and a2 exist, but in the portion below the line A, only one set of horizontal line segments exists on the scan line. On the contrary, in the portion above the line B, only one set of horizontal line segments exists on the scanning line, but in the portion below the line B, two sets of horizontal line segments b1 and b2 appear on the scanning line. . Therefore, when the number of horizontal line segments changes in this way from 2 → 1 → 2, the pattern can be recognized as a fusion pattern. A fusion pattern can be discovered by such a method.

When the fusion pattern is found, it is separated into two patterns by the procedure shown in the flowchart of FIG. First, in step S1, a ratio of widths of horizontal line segments immediately before line A (immediately before fusion) is obtained. In this example, the ratio a1: a2 is obtained. Then, step S2
In, the width ratio of the horizontal line segment immediately after line B (immediately after branching) is obtained. In this example, the ratio b1: b2 is obtained. Based on these ratios, the separation point x is obtained in the section of lines A to B. First, in step S3, attention is paid to the line A. Then, in step S4, the separation point x is obtained on the line of interest, and in step S5,
The two separated horizontal line segments are added as elements constituting the left and right conduits. This process is performed in step S6.
Through S7, line by line is repeated, and when line B is reached, the process is completed.

Here, the separation point x in step S4
Can be determined as follows. That is, as shown in FIG. 29, the total width on an arbitrary line X is w, the width of the horizontal line segment on the left side of the separation point x is w1, and the width of the horizontal line segment on the right side is w2.
Then, w1 = (w / (c + d)) * (d * a1 / (a1 + a)
2) + c · b1 / (b1 + b2)) w2 = (w / (c + d)) · (d · a2 / (a1 + a)
2) + c · b2 / (b1 + b2)) is required to determine w1 and w2.

The present invention has been described above based on several illustrated embodiments, but the present invention is not limited to these embodiments and can be implemented in various modes other than this. . For example, in the above embodiment, FIG.
When a figure K as shown in Fig. 4 is obtained, depth information is given to each position in the figure K and output as a gradation image to obtain an original film. On the other hand, it is also possible to perform a transformation process inside the computer and output the transformed gradation image on the original film. For example, the conduits of natural trees are very small, but the root side is thick and the treetop side is thin. In order to emphasize this property, a modification process may be performed such that the upper width of the figure K shown in FIG. 27B is narrowed and the lower width thereof is thickened.
Although the original pattern of the natural wood is deformed by such deformation processing, it is understood as a pattern closer to the natural wood in terms of design. Alternatively, since there is a so-called node in the conduit of the natural wood, if such a node is faithfully reproduced, as shown in FIG. 31, a pseudo node n1, inside the groove in the geometric model.
Assuming n2 and n3, the pseudo node portion (the portion indicated by the alternate long and short dash line in the plane pattern shown in the upper part of FIG. 31) may be shallowed by the depth of the node.

Further, for example, the embossed plate 4 shown in FIG.
In No. 1, the inclined portion seen in the cross section of the convex portion has a linear shape, but it is also possible to replace this with a continuous curve that is convex upward such as a logarithmic curve. In particular, it is preferable to use a continuous curve in which the slope gradually approaches 0 (horizontal) as it gets closer to the top, because a groove having a depth closer to that of a natural conduit groove can be reproduced.

Further, when a gradation image is output on the original film based on the result of the depth information calculation, the contour portion of the elliptical wood-pipe conduit cross-section pattern may become unclear. For example, in the original film shown in FIGS. 13 (a) and 17 (a), the outline of an ellipse is drawn as a black line in the drawing, but the gradation image based on the result of the depth information calculation is as follows. It does not include the outline. Therefore, even in the finally obtained embossed plate, the outline portion may be unclear. In such a case, it is advisable to superimpose an image in which only the contour line is drawn on the gradation image based on the result of the depth information calculation. This is because the exposure is performed in a state in which the first original film that outputs the gradation image based on the result of the depth information calculation is overlapped with the second original film that outputs the image in which only the outline is drawn. Alternatively, both images may be output by superimposing them on one original film. Further, the method of inputting the cross-sectional pattern of the natural wood grain conduit as digital image data is not limited to the input by the scanner device, and the image extracted by the television camera or the photograph is AD by an appropriate method.
You may use the method of converting. The digital image data input in this way is usually stored in a storage device such as a magnetic disk.

Further, in the embodiment of the depth information calculation described above, the cylindrical model is used as the geometric model, but an elliptic cylinder or a cone may be used instead.

[0077]

As described above, according to the method for producing a wood grain conduit groove embossing plate according to the present invention, depth information is calculated by calculating the depth information for a wood grain conduit cross section pattern having only contour information. Since the embossing plate is created using the original film that expresses the information of as the density, it becomes possible to create the embossing plate that faithfully reproduces the information of the depth of the natural wood grain conduit groove.

[Brief description of drawings]

FIG. 1 is a view showing an example of a wood grain conduit cross-sectional pattern appearing on a general natural wood lumber board.

FIG. 2 is an enlarged view of a circular partial area U of the pattern shown in FIG.

FIG. 3 is a diagram illustrating the depth distribution of conduit grooves obtained when a general natural tree is cut.

FIG. 4 is a diagram showing a plane pattern and a cross section of a convex portion of a conventional general wood grain conduit groove embossing plate.

5 is a diagram showing a plane pattern and a cross section of a concave portion of a wood grain print product obtained by embossing using the wood grain conduit groove embossing plate shown in FIG.

FIG. 6 is a view showing a plane pattern and a cross section of a convex portion of an ideal wood grain conduit groove embossing plate to be produced by the method of the present invention.

FIG. 7 is a diagram showing a plane pattern and a cross section of recesses of a wood grain print product obtained by embossing using the wood grain conduit groove embossing plate shown in FIG. 6;

FIG. 8 is a diagram showing a gradation image of a negative original film used in the present invention and its physical characteristics.

9 is a cross-sectional view showing a state where the negative original film 30 shown in FIG. 8 is placed on the resist transfer film 100.

FIG. 10 shows a case where exposure is performed in the state shown in FIG.
FIG. 6 is a cross-sectional view showing a distribution state of a photosensitive portion and a non-photosensitive portion in the resist.

11 is a plan view of the photosensitive member 21 of the resist shown in FIG.
It is sectional drawing which shows the state transferred on 0.

FIG. 12 is a cross-sectional view showing a state after performing an etching process from the upper surface in the state shown in FIG. 11.

FIG. 13 is a diagram showing a gradation image of a positive original film used in the present invention and its physical characteristics.

FIG. 14 shows a positive resist 60 formed on the plate material 50.
It is sectional drawing which shows the state which put the positive original film shown in FIG. 13 on it.

FIG. 15 is a cross-sectional view showing a distribution state of exposed portions and unexposed portions in a resist when exposure is performed in the state shown in FIG.

16 is a cross-sectional view showing a state where development is performed in the state shown in FIG. 15 and only the unexposed portion 62 is left on the plate material 50. FIG.

FIG. 17 is a diagram showing a gradation image of another negative original film used in the present invention and its physical characteristics.

FIG. 18 is a cross-sectional view showing a state where the negative original film 31 shown in FIG. 17 is placed on the resist transfer film 100.

FIG. 19 is a cross-sectional view showing a distribution state of exposed portions and unexposed portions in the resist when exposure is performed in the state shown in FIG.

20 is a plan view of the photosensitive member 23 of the resist shown in FIG.
It is sectional drawing which shows the state transferred on 0.

FIG. 21 is a cross-sectional view showing a state after performing an etching process from the upper surface in the state shown in FIG. 20.

22 is an auxiliary film 8 on the surface in the state shown in FIG.
It is sectional drawing which shows the state which formed 3.

FIG. 23 is a shallow depth inversion groove 82 in the state shown in FIG. 22.
It is sectional drawing which shows the state which filled the filler 84 inside.

FIG. 24 is a cross-sectional view showing a state after performing an etching process using the filler 84 as a mask in the state shown in FIG. 23.

25 is a cross-sectional view showing a state in which the auxiliary film 83 and the filler 84 have been removed in the state shown in FIG.

FIG. 26 shows a geometric model assuming that the conduit has a geometrically perfect cylindrical shape.

FIG. 27 is a diagram showing a correspondence relationship between a wood grain conduit cross-sectional pattern used in the depth information calculation according to the present invention and its approximate ellipse.

FIG. 28 is a block diagram showing a basic configuration of a depth information calculation device for a wood grain conduit cross-section pattern according to the present invention.

FIG. 29 is a diagram showing an example of a fusion pattern found in an actual wood grain conduit cross-sectional pattern.

FIG. 30 is a flowchart showing a procedure for separating a fusion pattern as shown in FIG. 29.

FIG. 31 is a diagram showing a state in which a node is reproduced in a wood grain conduit groove in the method for producing a wood grain conduit groove embossing plate according to the present invention.

[Explanation of symbols]

1 ... Pattern input means 2 ... Approximate ellipse defining means 3 ... Corresponding point calculation means 4 ... Depth information calculation means 10 ... Support film 20 ... Negative photosensitive resist 21 ... Photosensitive part 22 ... Unexposed area 30 ... Negative original film 31 ... Negative original film 40 ... Plate material 41 ... Embossed version 50 ... Plate material 60 ... Positive photosensitive resist 61 ... Photosensitive part 62 ... Unexposed area 70 ... Positive type original film 80 ... Plate material 81 ... Intermediate 82 ... Shallow depth inversion groove 83 ... Auxiliary membrane 84 ... Filler 85 ... Embossed version A, B ... Scan line C, C1, C2, C3 ... Cut surface D ... Diameter of conduit T E, E '... Embossed version G ... Conduit groove J ... Oval K ... Graphic of cross section of wood grain conduit L ... longitudinal direction P ... Elliptical pattern S, S '... wood grain print T ... conduit U: Circular area V: Length of major axis of ellipse W ... The length of the minor axis of the ellipse

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yasuhiro Hayashi 1-1-1, Ichigayakamachi, Shinjuku-ku, Tokyo Within Dai Nippon Printing Co., Ltd. (72) Inventor Hideki Murota 1-1-1, Ichigayaka, Shinjuku-ku, Tokyo No. 1 Dai Nippon Printing Co., Ltd. (72) Inventor Ieji Hashizume 1-1-1 Ichigaya Kaga-cho, Shinjuku-ku, Tokyo Inside 1-1 Dai Nippon Printing Co., Ltd. (72) Toshio Ariyoshi Toshio Ariyoshi, Shinjuku-ku, Tokyo 1-1-1 1-1 Dai Nippon Printing Co., Ltd. (72) Inventor Yu Okamoto 1-1-1 Ichigaya-Kagacho, Shinjuku-ku, Tokyo Dai Nippon Printing Co., Ltd. (72) Inventor Yoshio Sukegawa Miyoshi Iruma-gun Saitama Machi Takemazawa 311 Stock company Dai Nippon Total Process Building Materials (56) Reference JP-A-5-305662 (JP, A) JP-A-5-247670 (JP, A) JP-A-5-214577 (JP , A) JP-A-63-104839 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) B29C 33/38 B29C 59/02

Claims (8)

(57) [Claims] 1. A method of creating an embossed plate that reproduces the uneven structure of a wood grain conduit groove, comprising the steps of preparing a wood grain conduit cross section pattern composed of a large number of closed regions as binary image data, and a wood grain conduit cross section. Based on the information of the contour line of the pattern, the depth information of the wood grain conduit groove is defined for each position inside the closed region surrounded by the contour line, and the binary image data is a gradation using the depth information as gradation. Converting into image data, and based on the gradation image data, creating a negative original film in which light transmittance is higher at a position where depth information indicating that the wood grain conduit groove is deeper is defined A step of exposing the negative type photosensitive resist film, where the photosensitive portion is cured, through the negative original plate film; A step of copying, a step of removing an unexposed portion of the resist film transferred onto the plate material by a development process, and a corrosive liquid acting on the plate material from the remaining resist film to make the residual resist film thin. And a step of performing an etching process such that the corrosion depth of the plate material is larger in the portion and the corrosion depth is smaller in the thicker portion, and the step of removing the residual resist film is defined, and the depth information of the wood grain conduit groove is defined. At this time, it approximates the contour line of the wood grain conduit cross-section pattern prepared as binary image data, and defines a geometrical approximate figure that can be expressed by a mathematical formula, for each position inside the closed region surrounded by the contour line. , Find corresponding points in the approximate figure having corresponding relative positions, create a geometrical section model of the conduit based on the dimensions of the approximate figure, and use this geometrical section model. Te, wood vessel grooves embossing plate creation method characterized by obtaining the depth information of the vessel grooves in each of the corresponding point positions. 2. A method for creating an embossed plate that reproduces the uneven structure of a wood grain conduit groove, comprising the steps of preparing a wood grain conduit cross section pattern composed of a large number of closed regions as binary image data, and a wood grain conduit cross section. Based on the information of the contour line of the pattern, the depth information of the wood grain conduit groove is defined for each position inside the closed region surrounded by the contour line, and the binary image data is a gradation using the depth information as gradation. Converting into image data, and based on the gradation image data, creating a positive original film in which light transmittance becomes lower at a position where depth information indicating that the wood grain conduit groove is deeper is defined And a step of forming a positive type photosensitive resist film on which a photosensitive portion is eluted during development on the surface of a plate material which is a material of an embossing plate, and the positive original plate film with respect to the resist film. Exposing through the resist film, removing the exposed portion of the resist film by a developing process, and causing a corrosive liquid to act on the plate material from above the remaining resist film, so that the thinner the remaining resist film is, the more corrosive the plate material is. When defining the depth information of the wood grain conduit groove, the binary image has a step of performing an etching process such that the corrosion depth becomes larger as the depth increases and becomes thicker, and the step of removing the residual resist film. Approximate the contour line of the wood grain conduit cross-sectional pattern prepared as data, define a geometrical approximate figure that can be expressed by a mathematical formula, for each position inside the closed area surrounded by the contour line, within the approximate figure Obtain corresponding points whose positions correspond to each other, create a geometrical cross-section model of the conduit based on the dimensions of the approximated figure, and use this geometrical cross-section model to create each pair. Wood vessel grooves embossing plate creation method characterized by obtaining the depth information of the conduit groove at the point position. 3. A method for producing an embossed plate that reproduces the uneven structure of a wood grain conduit groove, comprising the steps of preparing a wood grain conduit cross section pattern composed of a large number of closed regions as binary image data, and a wood grain conduit cross section. Based on the information of the contour line of the pattern, the depth information of the wood grain conduit groove is defined for each position inside the closed region surrounded by the contour line, and the binary image data is gradation using the depth information as gradation. The step of converting into image data, based on the gradation image data, on the surface of the plate material which is the material of the embossing plate, the depth information indicating that the wood grain conduit groove is deeper is made shallower at the defined position. Forming a shallow depth inversion groove having a shallow depth relationship reversed from that of the wood grain conduit groove;
Etching treatment step, filling the shallow inversion groove with a filler having corrosion resistance, and causing a corrosive liquid to act from the surface of the plate material to surface the area not filled with the filler. A second etching treatment step of removing corrosion from the side, and a step of removing the filler, and in defining the depth information of the wood grain conduit groove, the wood grain conduit cross-sectional pattern prepared as binary image data. A geometrical approximation figure that can be represented by a mathematical formula, and each position inside the closed area surrounded by the contour line has a corresponding point to which the position relatively corresponds. Based on the dimensions of the approximated figure, a geometric section model of the conduit is created, and using this geometric section model, depth information of the conduit groove at each corresponding point position is obtained. How to make eye conduit groove embossed plate. 4. A method for producing an embossed plate that reproduces the concavo-convex structure of a wood grain conduit groove, comprising the steps of preparing a wood grain conduit cross section pattern composed of a large number of closed regions as binary image data, and a wood grain conduit cross section. Based on the information of the contour line of the pattern, the depth information of the wood grain conduit groove is defined for each position inside the closed region surrounded by the contour line, and the binary image data is gradation using the depth information as gradation. The step of converting into image data, based on the gradation image data, inside the closed region, the light transmittance becomes higher at a position where depth information indicating that the wood grain conduit groove is deeper is defined, and the closed region As for the outside, the step of producing a negative original film having almost the same maximum transmittance, and the negative original film is passed through a negative type photosensitive resist film in which the photosensitive part is cured. Exposing, a step of transferring the resist film to the surface of a plate material which is a material of an embossing plate, a step of removing an unexposed portion of the resist film transferred on the plate material by a developing treatment, An etching liquid is caused to act on the plate material from the remaining resist film, and etching is performed so that the thinner the residual resist film is, the larger the corrosion depth of the plate material is, and the thicker the resist film is, the smaller the corrosion depth is. Is a first etching treatment step of forming a shallow depth inversion groove in which the shallow depth relationship is reversed, a step of removing the residual resist film, and filling the shallow depth inversion groove with a filler having corrosion resistance. A second etching treatment step of causing a corrosive liquid to act from the surface of the plate material to corrode and remove a region not filled with the filler from the surface side, and a step of removing the filler. Shi When defining the depth information of the wood grain conduit groove, it is approximated to the contour line of the wood grain conduit cross-sectional pattern prepared as binary image data, and a geometrical approximation figure that can be expressed by a mathematical formula is defined, and surrounded by the contour line. For each position inside the closed area, the corresponding points in the approximated figure that correspond to the relative position are obtained, and based on the dimensions of the approximated figure, a geometrical cross-section model of the conduit is created. A method for producing a wood grain conduit groove embossing plate, characterized in that depth information of the conduit groove at each corresponding point position is obtained using a model. 5. A method for producing an embossed plate that reproduces the concavo-convex structure of a wood grain conduit groove, comprising the steps of preparing a wood grain conduit cross section pattern composed of a large number of closed regions as binary image data, and a wood grain conduit cross section. Based on the information of the contour line of the pattern, the depth information of the wood grain conduit groove is defined for each position inside the closed region surrounded by the contour line, and the binary image data is gradation using the depth information as gradation. The step of converting into image data, and based on the gradation image data, inside the closed region, the light transmittance becomes lower at the position where the depth information indicating that the wood grain conduit groove is deeper is defined, and the closed region As for the outside, the step of making a positive master plate film that has almost the same minimum transmittance and the positive type photosensitive resist film that the photosensitive part elutes during development are used as the material for the embossing plate. Forming on the surface of the resist film, exposing the resist film through the positive master film, removing the exposed portion of the resist film by a developing process, and removing a corrosive liquid from the remaining resist film. Etching is performed on the plate material such that the thinner the residual resist film is, the larger the corrosion depth of the plate material is, and the thicker the resist film is, the smaller the corrosion depth is. A first etching treatment step of forming a reverse groove, a step of removing the residual resist film, a step of filling the shallow depth reverse groove with a filler having corrosion resistance, and A second etching treatment step of causing a corrosive liquid to act so as to corrode and remove the area not filled with the filler from the surface side; and a step of removing the filler, When defining the degree information, a geometrical approximate figure that can be expressed by a mathematical formula that approximates the contour line of the wood grain conduit cross-sectional pattern prepared as binary image data is defined, and a closed area surrounded by the contour line is defined. For each internal position, the corresponding points in which the relative positions in the approximated figure are relatively determined are obtained, and based on the dimensions of the approximated figure, a geometric cross-section model of the conduit is created, and this geometric cross-section model is used. A method for producing a wood grain conduit groove embossing plate, characterized in that depth information of the conduit groove at each corresponding point position is obtained. 6. A method for producing an embossing plate that reproduces the concavo-convex structure of a wood grain conduit groove, comprising the steps of preparing a wood grain conduit cross section pattern composed of a large number of closed regions as binary image data, and a wood grain conduit cross section. Based on the information of the contour line of the pattern, the depth information of the wood grain conduit groove is defined for each position inside the closed region surrounded by the contour line, and the binary image data is gradation using the depth information as gradation. Converting into image data, preparing a resist transfer film formed by forming a negative photosensitive resist film on which a photosensitive portion is cured on a predetermined support, and based on the gradation image data The light beam scanning is performed on the resist transfer film while modulating the light beam intensity so that the light intensity becomes stronger at a position where depth information indicating that the conduit groove is deeper is defined. A step of exposing the resist film, a step of transferring the resist film to a surface of a plate material which is a material of an embossing plate, and a developing treatment of an unexposed portion of the resist film transferred onto the plate material. An etching process is performed so that the plate material is exposed to a corrosive liquid from the remaining resist film and the remaining resist film has a greater corrosion depth and a thicker part has a smaller corrosion depth. A step of removing the residual resist film, and, when defining depth information of the wood grain conduit groove, approximate the contour line of the wood grain conduit cross-sectional pattern prepared as binary image data, and A geometrical approximate figure that can be expressed is defined, and for each position inside the closed area surrounded by the contour line, a corresponding point whose position relatively corresponds in the approximate figure. Obtained, based on the dimensions of the approximate figure, to create a geometric cross-section model of the conduit, using this geometric cross-section model, to obtain depth information of the conduit groove at each of the corresponding point positions, the wood grain conduit How to make a groove embossed plate. 7. A method for producing an embossed plate that reproduces the uneven structure of a wood grain conduit groove, comprising the steps of preparing a wood grain conduit cross section pattern composed of a large number of closed regions as binary image data, and a wood grain conduit cross section. Based on the information of the contour line of the pattern, the depth information of the wood grain conduit groove is defined for each position inside the closed region surrounded by the contour line, and the binary image data is a gradation using the depth information as gradation. Converting the image data into image data, forming a positive type photosensitive resist film on the surface of the plate material that becomes the material of the embossing plate, the photosensitive portion of which elutes during development, based on the gradation image data The light beam scanning is performed on the resist film while modulating the light beam intensity so that the light intensity becomes weaker at a position where depth information indicating that the conduit groove is deeper is defined. And exposing the exposed portion of the resist film by a developing process, and causing a corrosive liquid to act on the plate material from above the remaining resist film, and the thinner the remaining resist film is, the deeper the corrosion depth of the plate material is. Of the binary image data to define the depth information of the wood grain conduit groove. Approximate to the contour line of the wood grain conduit cross-sectional pattern prepared as, to define a geometrical approximate figure that can be expressed by a mathematical formula, for each position inside the closed region surrounded by the contour line, within the approximate figure The corresponding points corresponding to the positions are obtained, based on the dimensions of the approximated figure, a geometric cross-section model of the conduit is created, and using this geometric cross-section model, Wood vessel grooves embossing plate creation method characterized by obtaining the depth information of the vessel grooves in 応点 position. 8. A method for producing an embossed plate that reproduces the concavo-convex structure of a wood grain conduit groove, comprising the steps of preparing a wood grain conduit cross section pattern composed of a large number of closed regions as binary image data, and a wood grain conduit cross section. Based on the information of the contour line of the pattern, the depth information of the wood grain conduit groove is defined for each position inside the closed region surrounded by the contour line, and the binary image data is a gradation having the depth information as the gradation. The step of converting into image data, and based on the gradation image data, the plate which is the material of the embossing plate is such that the cutting depth becomes deeper at the position where the depth information indicating that the wood grain conduit groove is shallower is defined. It has a step of cutting the surface of the material, and, when defining the depth information of the wood grain conduit groove, it can be expressed by a mathematical formula by approximating to the contour line of the wood grain conduit cross-sectional pattern prepared as binary image data. Mathematically approximated figure is defined, for each position inside the closed area surrounded by the contour line, a corresponding point in which the position relatively corresponds in the approximated figure is obtained, and based on the dimension of the approximated figure. A method for producing a wood grain conduit groove embossing plate, characterized in that a geometric sectional model of a conduit is created, and depth information of the conduit groove at each corresponding point position is obtained using this geometric sectional model.