EP2921581A1

EP2921581A1 - Knit design system and knit design method

Info

Publication number: EP2921581A1
Application number: EP15159448.8A
Authority: EP
Inventors: Koichi Terai; Hirofumi Honda
Original assignee: Shima Seiki Mfg Ltd
Current assignee: Shima Seiki Mfg Ltd
Priority date: 2014-03-18
Filing date: 2015-03-17
Publication date: 2015-09-23
Anticipated expiration: 2035-03-17
Also published as: KR101690527B1; JP2015175083A; JP6109105B2; CN104933217B; EP2921581B1; CN104933217A; KR20150108776A

Abstract

It is an object of the present invention to enable calculation of an external size of a knit fabric in a short time.

Configuration: Two types of array pitches of stitches, an array pitch in the course direction and an array pitch in the wale direction are stored such that the array pitch where the same type of stitches are connected to each other and an array pitch where different types of stitches are connected to each other are different from each other. Grid lines of an array of stitches in the course direction are deformed into the wale direction according to an average of pitches in the wale direction of the stitches belonging to the respective grid lines. Furthermore, grid lines of an array of stitches in the wale direction are deformed into the course direction according to an average of pitches in the course direction of stitches belonging to the respective grid lines. Then, the external shape of the unit fabric is obtained based on the deformed grid lines.

Description

Technical Field

The present invention relates to knit design, and particularly relates to calculation of an external size of a knit fabric.

Background Art

Knit fabrics have the problem that it is difficult to knit a product having a size as directed. The possible reason is, for example, that:

the loop length of stitches deviates from a target value;
the size varies due to finish processing after knitting;
it is often the case that a knit fabric is not constituted by only face stitches or rear stitches, but includes both face stitches and rear stitches, a side movement structure, and the like; or
stitches that are connected to each other in the course or wale direction interact with each other, varying the size of the stitches intricately.

Patent Literature 1 ( JP 2676182B ) discloses that a plurality of texture samples are knitted while controlling the loop length, and the most appropriate texture sample is selected after finish processing. By performing knitting according to the loop length of the most appropriate sample, a knit fabric that has a size close to a target size and an excellent texture is obtained. However, by the method of Patent Literature 1, it is difficult to knit a knit fabric that is constituted by a mixture of face stitches and rear stitches and has a side movement structure, in a size as directed.
Patent Literature 2 ( WO 2007/013296A ) discloses simulation of a three-dimensional shape of a knit fabric. Particularly, a tension, a distortion, and a flexure that are applied to each stitch are calculated and the position of the stitch is shifted. In order to simulate the shape of a knit fabric, it is necessary to repeatedly perform calculation until the shape of the knit fabric converges.
Patent Literature 3 ( JP 2009-120987A ) discloses that if it is necessary to change the course number between right and left parts of a knit fabric, that is, between a part of the knitting width and the remaining part, differences in course number are arranged in a distributed manner in the wale direction.

Citation List

Patent Literature

[Patent Literature 1]	JP 2676182B
[Patent Literature 2]	WO 2007/013296A
[Patent Literature 3]	JP 2009-120987A

Summary of the Invention

Problems to be Solved by the Invention

An ordinary knit fabric, in particular, a knit fabric garment is constituted by a mixture of face stitches and rear stitches and has a side movement structure. A structure pattern often includes a mixture of face stitches and rear stitches, and a side movement structure that is made due to increased stitches, decreased stitches, bind-off stitches, or the like.
Accordingly, it is necessary to enable checking in a short time whether or not a knit fabric such as a garment can be knitted in a size as directed. If it is recognized that such knitting of a knit fabric is impossible, shape data, pattern data, knit design data, or the like on the knit fabric is corrected, and if necessary, it is checked whether or not a fabric having a size as directed can be knitted with the corrected data. Accordingly, it is possible to create knit design data or the like for obtaining a knit fabric having a size substantially as directed, without knitting an actual sample and performing time consuming simulation.
It is an object of the present invention to enable checking in a short time whether or not a knit fabric having a size as directed can be knitted.
In particular, it is an object of the present invention to enable calculation of an external size of a knit fabric in a short time.

Means for Solving Problem

The present invention is directed to a knit design system that is configured to obtain, based on knit design data or knit data, an external size of a knit fabric in which stitches are arrayed in a course direction and a wale direction, and that includes: a pitch storage unit configured to store two types of array pitches of the stitches, an array pitch in the course direction and an array pitch in the wale direction, such that the array pitch where the same type of stitches are connected to each other and the array pitch where different types of stitches are connected to each other are different from each other;
a grid line deforming unit configured to deform grid lines of an array of stitches in the course direction into the wale direction according to an average of pitches in the wale direction of the stitches belonging to the respective grid lines, and to deform grid lines of an array of stitches in the wale direction into the course direction according to an average of pitches in the course direction of the stitches belonging to the respective grid lines; and
an external shape extraction unit configured to obtain an external shape of the knit fabric based on the deformed grid lines,
the external shape of the knit fabric being obtained by deformation of the grid lines according to the array pitches of the stitches.
Furthermore, the present invention is further directed to a knit design method for obtaining an external size of a knit fabric in which stitches are arrayed in a course direction and a wale direction based on knit design data or knit data using a knit design system, the method including steps for:

the knit design system storing two types of array pitches of the stitches, an array pitch in the course direction and an array pitch in the wale direction, the array pitch where the same type of stitches are connected to each other and the array pitch where different types of stitches are connected to each other being different from each other;
the knit design system deforming grid lines of an array of stitches in the course direction into the wale direction according to an average of pitches in the wale direction of the stitches belonging to the respective grid lines, and to deform grid lines of an array of stitches in the wale direction into the course direction according to an average of pitches in the course direction of the stitches belonging to the respective grid lines; and
obtaining an external shape of the knit fabric based on the deformed grid lines,
the external shape of the knit fabric being obtained by deformation of the grid lines according to the array pitches of the stitches.

In the present invention, it is possible to obtain an actual arrangement of stitches in a short time without performing repeated calculation. Therefore, it is possible to obtain an external shape of a knit fabric in a short time, making it possible to, for example, evaluate an error in size between a design of the knit fabric and a knit fabric after completion in a short time. A knit fabric can easily be designed or the design can easily be corrected so that the knit fabric has a target size. Note that in the specification, the description regarding the knit design system is also applied directly to the knit design method. In this specification, knit design data refers to design data on a knit fabric, and knit data refers to data for knitting a knit fabric by a knitting machine, and the knit design data is capable of being converted into the knit data.
It is preferable that the average is a moving average along a grid line, and the average varies depending on the position on the grid line. An interaction acts on stitches that are close to each other so as to align their positions, and an interaction that acts on stitches that are apart from each other is weak. Therefore, a moving average is used to obtain an arrangement of stitches that is closer to an actual arrangement.
Furthermore, it is preferable that a pitch in the course direction and a pitch in the wale direction when a stitch is moved to a side in the course direction be stored in the pitch storage unit, or be calculated using the array pitches stored in the pitch storage unit. In the case, for example, where a knit fabric is a garment, stitches that are moved to the side are included due to increased stitches, decreased stitches, bind-off stitches, a structure pattern, or the like. Furthermore, it is also possible to obtain, in a short time, the shape of a knit fabric including stitches that are moved to the side by deforming grid lines.
Preferably, the knit design system includes a smoothing unit configured to smooth positions of stitches defined by the deformed grid lines with respect to stitches at an end of the knit fabric. In the deformation of grid lines, stitches at an end or in the vicinity of the end may be arranged in unnatural positions. Accordingly, by smoothing, the stitches at the end can be arranged at more real positions. Smoothing can be executed by applying, for example, the method of Patent Literature 2 to stitches of a knit fabric, or stitches at an end of a part when the knit fabric is constituted by a plurality of parts.
Preferably, the knit design system includes a loop arrangement unit configured to arrange images showing stitches in loops of yarns such that the yarns are connected to each other, based on types of stitches, positions of stitches defined by the deformed grid lines, and connection relationship between stitches. The arrangement of stitches has been corrected by deformation of grid lines. Furthermore, since the types of stitches and connection relationship between stitches are already known from the design of the knit fabric or the like, it is possible to easily display the stitches with images of loops of yarns. Therefore, it is possible to display a knit fabric in loops in a short time. Note that more real display in loops is possible by smoothing an arrangement of stitches at an end.
Preferably, the knit design system includes a display control unit configured to display an image showing a target size of the knit fabric and an image of the knit fabric defined by the deformed grid lines on a color monitor in an overlapping manner, and to accept a change of data for defining design of the knit fabric. Accordingly, it is possible to display how much extent of deviation from the target size of a knit fabric occurs in which area. Accordingly, it is possible to immediately determine whether or not it is necessary to change the design of a knit fabric, and if it is necessary to change the design, changing the design is possible. It is particularly preferable that the color monitor is divided into two screens or more, and an image showing the target size of a knit fabric and an image of the knit fabric defined by the deformed grid lines are displayed on one screen in an overlapping manner. Also, a change of data that defines the design is accepted from another screen.

Brief Description of the Drawings

FIG. 1 is a block diagram showing a knit design apparatus according to an embodiment.
FIG. 2 is a diagram showing processes of the embodiment.
FIG. 3 is a diagram schematically showing calculation of external shape data on a knit fabric.
FIG. 4 is a flowchart showing an algorithm for obtaining gauges and pitches in the embodiment.
FIG. 5 is a flowchart showing an algorithm for calculating an external size of a knit fabric in the embodiment.
FIG. 6 is a diagram showing pitches of stitches and grid lines in the embodiment.
FIG. 7 is a diagram showing a method for calculating a pitch of a stich that is moved to the side in the embodiment.
FIG. 8 is a diagram showing another method for calculating a pitch of a stich that is moved to the side in the embodiment.
FIG. 9 is a diagram showing yet another method for calculating a pitch of a stich that is moved to the side in the embodiment.
FIG. 10 is a diagram showing a method for calculating a pitch of a stretched stitch in the embodiment.
FIG. 11 is a diagram showing deformation of the grid lines of the embodiment with respect to a 2×2 cable pattern.
FIG. 12 is a diagram showing deformation of the grid lines of the embodiment with respect to a part having a bind-off.
FIG. 13 is a flowchart showing smoothing performed at an end of a part after the external size was obtained in the embodiment.
FIG. 14 is a flowchart showing an algorithm for displaying loops in the embodiment.
FIG. 15 is a flowchart showing an algorithm for correcting a knit design in the embodiment.

Description of Embodiments

Hereinafter, an optimal embodiment for carrying out the present invention will be described.

Embodiment

FIGS. 1 to 15 show an embodiment and, specifically, FIG. 1 shows a knit design apparatus 2 according to the embodiment, in which the reference numeral 4 denotes a bus, the reference numeral 6 denotes a color monitor, the reference numeral 8 denotes a manual input device such as a stylus, a mouse, and a keyboard. The reference numeral 10 denotes a file input/output device, such as a LAN interface, a disk drive, or an external memory, that inputs/outputs a file such as a directed size, knit design data, and knit data. The reference numeral 12 denotes a color printer, and the reference numeral 14 denotes a memory that stores arbitrary data, a database, a program, and the like. Additionally, a CPU (not shown) is provided.
Designing a knit fabric starts with defining the shape of each part of the knit fabric based on a directed size and the like. Pattern data is data obtained by converting the shape into stitch numbers in the course and wale directions. Knit design data is design data that indicates stitch numbers in the course and wale directions, the type of each stitch, connection relationship between stitches, and the like, and is based on the pattern data. Design that is designated by the pattern data, the knit design data, or the like is referred to as knit design. Knit data is data that is used for driving a knitting machine such as a flat knitting machine or a circular knitting machine to knit a knit fabric according to the knit design data, and is obtained by converting the knit design data into data for driving a knitting machine.
A knit design unit 16 designs a knit fabric based on a file that was input from the file input/output device 10, a manual input from the manual input device 8, or the like. The knit design unit 16 then outputs knit design data on the designed knit fabric, converts the knit design data into knit data, and outputs the converted knit data.
A pitch storage unit 17 stores gauges and pitches of stitches. The gauges are numbers of stitches per a predetermined length and include a gauge in the course direction and a gauge in the wale direction. The gauges can be measured by, for example, the most appropriate texture sample. Note that gauges show the size of stitches of a structure constituted by only face stitches or rear stitches. When a face stitch and a rear stitch are connected to each other, the pitch between the stitches is problematic. Pitches include a pitch between face and face stitches, a pitch between rear and rear stitches, and a pitch between face and rear stitches, the pitch between face and face stitches and the pitch between rear and rear stitches being equal to each other. Furthermore, the pitch between face and rear stitches and the pitch between rear and face stitches are equal to each other. Pitches include a pitch in the course direction (x direction in FIG. 6 and the like) and a pitch in the wale direction (y direction in FIG. 6 and the like). The reason why the pitch between face and rear stitches, or the like is problematic is that a knit structure such as a rib, a garter, or a structure pattern is included, and gauges suffice in the case of a structure constituted by only face stitches or rear stitches. The pitch storage unit 17 may also store, in addition thereto, a pitch of a stitch that is moved to the side.
An external shape calculation unit 18 calculates an external size of a knit fabric according to knit data, based on the gauges and pitches of stitches in the pitch storage unit 17. The external shape calculation unit 18 includes a grid line deforming unit 19 that arranges stitches on lines in the course direction and lines in the wale direction (they are referred to as grid lines) and deforms the grid lines based on the pitch of stitches and side movement. The external shape calculation unit 18 further includes an external shape extraction unit 20 that obtains the external shape, in particular, the external size of a knit fabric based on the deformed grid lines. Note that positions of stitches become clear from the deformed grid lines.
In the deformation of grid lines, stitches connected to each other in the course direction are shifted while being aligned, and also stitches connected to each other in the wale direction are shifted while being aligned. Therefore, not shifting of each stitch but deformation of the grid lines is calculated. Then, the extent that stitches are shifted while being aligned is defined using a moving average or an average over the entire length in the course or wale direction, and is particularly defined with a length that is obtained by averaging using a moving average. In the present invention, since grid lines are deformed, stitches do not shifted without being aligned, thus eliminating the need to perform repeated calculation for obtaining an external shape. Furthermore, if the position of each stitch becomes clear, the external shape of a knit fabric will also become clear. Accordingly, it is possible to calculate the external shape of a knit fabric or the external shape of a part of a knit fabric in a short time. Therefore, it is possible to calculate the external size in a short time.
A grid line deforming unit 19 obtains the positions of stitches by deforming grid lines. However, at an end of a knit fabric or a part thereof, positions of stitches may be disordered. Accordingly, it is preferable to smooth the stitch positions of stitches at the end or stitches within a predetermined number of courses (such as, for example, 5 courses or 3 courses) from the end by a smoothing unit 24.
A loop arrangement unit 26 generates an image in which stitches are depicted in loops based on the stitch positions obtained by the external shape calculation unit 18, or stitch positions obtained by the smoothing unit 24 smoothing the stitch positions. From data that was input into the loop arrangement unit 26, the reference position (for example, a starting position), the end position, and the like of the stitches become clear, and connection relationship between stitches and the types of the stitches also become clear. The loop arrangement unit 26 depicts the stitches in loops of yarns according to the data.
A display control unit 28 controls display on the color monitor 6, and interprets an input from the manual input device 8. For example, the screen of the color monitor 6 is divided into two screens or the like, and on one screen, a design based on a directed size and the external shape obtained by the external shape extraction unit 20 are displayed in an overlapping manner so that a user can check an error. On another screen, correction of the pattern data, correction of design of a structure pattern, adding of a stitch, deletion of a stitch, or the like is accepted.
FIG. 2 shows processes in the embodiment, and in process p1, knit design data and knit data are created by designating size data (directed size) that directs the size of a knit fabric, texture data (gauges or the like), types of stitches, and connection relationship of stitches. In process p2, grid lines are deformed based on gauges in the course and wale directions, pitches between face and rear stitches in the course and wale directions, and pitches between stitches that are moved to the side in the course and wale directions. Stitches are located at intersection points of grid lines in the course direction and grid lines in the wale direction, and if the grid lines are defined, the positions of stitches are defined.
Processes p3 to p5 may be omitted, and in process p3, a stitch arrangement in the vicinity of an end is smoothed, and in process p4, each stitch is replaced by an image of a loop. In process P5, the shape of a knit fabric according to a directed size, and the external shape of the knit fabric obtained by the external shape calculation unit 18 and the like are displayed in an overlapping manner on one screen. Furthermore, correction of pattern data, knit design data, or the like is accepted in accordance with a manual input from the other screen.
FIG. 3 schematically shows calculation of the external size of a knit fabric, and a box 30 shows knit data, that is, the box 30 actually shows the types of stitches and a side movement structure or the like in different colors. A box 31 shows external shape data on the knit fabric, and a box 32 shows enlarged stitch arrangement of the box 31. The stitches are arranged in grids in the course and wale directions. Each stitch is connected to upper, lower, right, and left stitches unless otherwise specified, and the connection relationship of stitches is shown when it is changed due to side movement or the like. In the display of the box 32, the size is not actual size since it does not reflect the change in the pitches due to the connection between face and rear stitches, side movement of stitches, or the like.
FIG. 4 shows an algorithm for obtaining gauges and pitches. A texture sample itself is well-known from Patent Literature 1, and in step S1, texture samples are designed so as to include a rib structure (face stitches and rear stitches appear alternately in the course direction) and a garter structure (face stitches and rear stitches appear alternately in the wale direction) in addition to structure constituted by only face stitches or rear stitches. Furthermore, the texture samples may also include a side movement structure and the like.
The knit design data of the texture samples is converted into knit data, a knit fabric is knitted by a flat knitting machine or the like, and finish processing is performed thereon (step S2). At that time, a plurality of texture samples are knitted while changing the loop length of each stitch, and the sample of the most appropriate texture is selected (step S3). If there is no most appropriate sample, a texture sample is knitted again with the loop length and the like changed.
With respect to the most appropriate texture sample, a pitch xp in the course direction and a pitch yp in the wale direction of stitches when face and face stitches and rear and rear stitches are adjacent to each other are obtained (step S4). By indicating these pitches as gauges, the gauges of the most appropriate texture sample are obtained and are used.
A pitch xp in the course direction and a pitch yp in the wale direction of stitches when face and rear stitches are adjacent to each other are obtained as pitches between face and rear stitches (step S5). These pitches include pitches in the case of a rib and pitches in the case of a garter, and which pitches to apply is determined according to the type of stitches in the knit data. In the case of a rear stitch or the like surrounded by face stitches, it is preferable to comply with a model (rule) in which, for example, the pitch xp in the course direction is determined by the pitch of stitches of a rib and the pitch yp in the wale direction is determined by the pitch of stitches of a garter, or it is preferable that such stitches are included in texture samples. Furthermore, if texture samples include a side movement structure or the like, a pitch in the course direction and a pitch in the wale direction of the side movement structure are obtained in step S6. With the above-described procedure, gauges and pitches that serve as bases of the size of stitches are obtained.
In a knit fabric, a stitch is connected to adjacent stitches in the course direction and adjacent stitches in the wale direction, and thus the shape of that stitch changes under the influence of the peripheral stitches. Processing shown in FIGS. 5 to 15 is performed for obtaining the external size of a knit fabric in a short time while taking into consideration the influence of the peripheral stitches, without repeatedly performing calculation.
In step S11 of FIG. 5, the shape of a knit fabric is defined based on a directed size and the like, in step S12, pattern data is obtained by converting the directed size and the like into stitch numbers based on gauges, and in step S13, knit design data is obtained by adding a knit structure, the types of stitches, and the like. Then, in step S 14, the knit design data is converted into knit data. Here, the stitch numbers do not reflect the facts that a face stitch and a rear stitch are connected to each other, stitches are moved to the side, and the like, and thus by performing knitting according to the knit data, a knit fabric that has the size different from the directed size is ordinarily realized.
In step S15, a grid line in the course direction and a grid line in the wale direction are deformed based on the pitch between face and rear stitches and the pitch of side movement, and more actual positions of stitches are obtained. In step S16, the external size of the knit fabric is calculated based on the obtained positions of the stitches.
A grid line model is shown in dashed lines in FIG. 6. Courses c1 to c4 and wales w1 to w5 are indicated, in which the wales w1 to w3 are face stitches and the wales w4 and w5 are rear stitches, and j denotes the course number and i denotes the wale number. A straight or curved line on which stitches are arranged in each of the courses c1 to c4 and the wales w1 to w5 are grid lines. Furthermore, the starting point of a knit fabric is arranged in, for example, the lower left portion of FIG. 6. The pitch between the wales w2 and w1 is assumed to be an average of pitches xpj in the x direction of four stitches (j = 1 to 4) of the wale w2. The pitch between the courses c1 and c2 is assumed to be an average of pitches ypi in the y direction of five stitches (i = 1 to 5) of the course c2. That is, stitches are not moved independently, but the grid lines in the course direction and the wale direction to which the stitches belong are deformed using an average or a moving average of pitches of stitches. Note that the pitches between the wales w1 and w2, the wales w4 and w5, and the like are equal to pitches that are defined by gauges. Furthermore, the pitch between the courses c1 and c2 is a weighted average of a pitch between face stitches × 3 and a pitch between rear stitches × 2, in which the weight is the stitch number of that pitch. Furthermore, the pitches from between the courses c1 and c2 to between the courses c3 and c4 are the same. Data for defining grid lines is, for example, a coordinate arrangement of intersection points (stitches) of the grid lines, and deforming the grid lines refers to moving the coordinates of stitches.
It is natural that a short grid line is close to a straight line and a long grid line deviates from a straight line. In other words, a pitch of one stitch must hardly influence the arrangement of stitches that are widely distanced from that stitch. Therefore, it is preferable to use a moving average that is obtained by averaging of stitches in the number that allows the positions of the stitches to be aligned on a straight line.
FIG. 7 shows calculation of a pitch that is moved to the side, and when the texture sample includes a stitch to be moved to the side, a measured value is used. It is assumed that the size itself of the stitch is not changed due to side movement, and the size (xp² + yp²)^1/2 is not changed, where xp and yp respectively refer to standard pitches that correspond to the pitch between face and face stitches and the pitch between face and rear stitches (the same applies to below). Then, a stitch 71 is rotated so as to be a stitch 72 along a circle 73 centered on the reference position, such as a base end, of the stitch. Note that another model for obtaining a pitch of side movement is conceivable and any approximating method between the model and the pitch may be used.
Additionally, FIGS. 8 and 9 show a method for calculating a pitch that is moved to the side. Only the direction is shown in which the pitch of the stitch that is moved to the side shrinks, and the pitch of this stitch between the wales 3 and 4 is considered, where in FIG. 8, the black circle (●) denotes the starting point of the stitch and the white circle (○) denotes the top end thereof. It is assumed that a denotes the top end position of the stitch before side movement, and a' denotes the position after side movement. It is assumed that when the position a' is on the wale 3, the pitch of this stitch between the wales 3 and 4 is 0. If x and y with respect to the position a' are defined as in FIG. 8, the pitch of this stitch between the wales 3 and 4 is -xp + x (where xp is a standard pitch), and the pitch between the courses 2 and 3 is y. Then, x and y are obtained assuming that the position a' is located on the line connecting between the base end and the position a and the distance between the position a' and the base end is equal to yp. FIG. 9 shows the same calculation example with respect to another stitch.
FIG. 10 shows a way of thinking of the pitch of a stretched stitch, and it is assumed that the top end of this stitch converges from a position b to a position b'. The pitch of this stitch between the courses 3 and 4 is considered, and it is assumed that the pitch is 0 when the top end positon b' is located on the grid line of j = 3. Since the top end position b' converges on the grid line of j = 2, it is assumed that the pitch between the courses 3 and 4 is -yp.
The models of FIGS. 8 and 9 are used to calculate pitches between courses and pitches between wales in FIG. 11. A course 1 and the like of FIG. 15 denotes a pitch between the courses 1 and 2, and the like. Furthermore, a to d are reference numerals of stitches. Note that the pitch between the wales 2 and 3 (xp + xp - (xp - xpa) + xp)/4 is obtained assuming that there are two stitches of a pitch xp, and the stitch a has a pitch - (xp - xpa), and the base end of the stitch c contributes the pitch xp. However, the detail of the calculation method may be changed arbitrarily.
The model of FIG. 10 and the model of FIG. 8 and the like are used to calculate pitches in FIG. 12. The pitch between the courses 3 and 4 is (2ypa + 0)/3, and contribution of the stitch a and the stitch of the same shape as that of the stitch a is 2ypa, and the top end of a stitch e is likely to converge on the grid line of j = 3, and thus contribution to the pitch is 0. The pitch between the courses 4 and 5, and the like are calculated in a similar manner. The pitch between the wales 1 and 2 is (2xp+xpa)/3 that is obtained by averaging, since the number of ordinary stitches is two and the contribution is 2xp and the contribution of the stitch a is xpa.
In this manner, pitches of each stitch in the course and wale directions are obtained and averaged for each grid line indicated by a dashed line, and thereby the position of the grid line after deformation is defined. Note that FIGS. 11 and 12 show a simple average, but a moving average is preferable if the grid line is long.
As described above, pitches in the case of side movement are:

measured using a texture sample; or
obtained directly using the model of FIGS. 8, 9, or 10, or using a model obtained by correcting that model of FIGS. 8, 9, or 10.

These pitches are stored in a pitch storage unit 17, or obtained each time by calculation of a grid line deforming unit 19. Furthermore, it is assumed that miss and tuck stitches are irrelevant to deformation of grid lines, but an appropriate model may also be defined separately. When it is determined how the grid line is deformed, the positions of stitches are defined. This processing is executed in a short time without repeated calculation, and thus the external size of a knit fabric is obtained in a short time.
The positions of stitches at the end of a part may be disordered since stitches are shifted in a unit of a grid line. In order to solve the disorder, processing in FIG. 13 is executed. In step S21, stitches at an end of a part or stitches within a predetermined number of courses such as 5 courses or 3 courses from the end are extracted. When the part is a body and the positon of the end is at an arm hole, the positions of stitches at the end may be changed by the stitches being connected to a sleeve and drawn by stitches of the sleeve. Therefore, when an end is connected to an end of another part, connection data of stitches of the other part is virtually added (step S22). When the stitch number of the end matches the stitch number of the other part, the stitches are connected to each other in a 1:1 relationship. If the stitch numbers do not match each other, connection by, for example, a double stitch is added.
In steps S23 and S24, only stitches in the vicinity of the end are subjected to processing disclosed in Patent Literature 2 or the like, and are smoothed. Detail of the processing is arbitrary, but, for example for each stitch, a tension based on the distance between the stitches, a distortion caused by the course direction and the wale direction being not orthogonal, and flexures in the course and wale directions based on the fact that ends of a knit fabric are likely to be curled are evaluated (step S23), and stitches are shifted based on these evaluated values (step S24). The processing time of the processing in FIG. 13 is short since it is performed only with respect to the vicinity of ends, and an arrangement of stitches that is closer to the actual arrangement is realized in the vicinity of ends.
An arrangement of stitches is obtained, and if the arrangement of stitches in the vicinity of an end is smoothed as desired, it is possible to simply display a knit fabric by depicting each stitch in a loop of a yarn. This processing is shown in FIG. 14, and in step S31, the reference point, the top end and the like of each stitch are extracted. Furthermore, the connection relationship of each stitch to the peripheral stitches and the type of the stitch, that is, a face or rear stitch are extracted (step S32). The data has been obtained by calculation of knit data and an external size, and the like. Accordingly, the positions and shapes of stitches, the connection relationship to the peripheral stitches, and the like become clear, and thus by arranging images of yarns according to the information such that ends of yarns are connected to each other at borders of the stitches, it is possible to display loops of the stitches (step S33).
FIG. 15 shows correction of the knit design with display of two screens. If the external size of a knit fabric becomes clear, it is recognized whether or not the external size matches the directed size. Therefore, the obtained external shape of a knit fabric is compared with the shape data or the like based on the directed size. Then, on one screen, an image of the external shape of a knit fabric and an image of the shape data are displayed in an overlapping manner (step S41), and an input for correction of the design is accepted from the other screen (step S42). For example, pattern data is corrected to add or delete a stitch, and the design of a knit structure is changed. In order to add a stitch to a part of the knit fabric, the processing as Patent Literature 3 is preferably used, for example. Furthermore, as desired, the external shape of a knit fabric having the corrected design is obtained (step S43), and the procedure returns to step S41, where it is checked whether or not the external shape matches the directed size.
In the embodiment, the following effects are achieved.

1) The external shape of a knit fabric is obtained in a short time.
2) A stitch arrangement that is closer to the actual arrangement is obtained by smoothing stitches in the vicinity of an end of a part.
3) A simple loop simulation is realized by replacing stitches by images of loops.
4) A knit fabric having a size as directed is knitted by viewing an error with respect to a directed size and correcting pattern data or the like.

Note that the present invention may also be used not for the purpose of matching the external size of a knit fabric with a directed size but for the purpose of a simple simulation of the knit fabric shape. When a plurality of types of yarns are used, it is preferable to knit texture samples including the respective yarns and to acquire the most appropriate loop length, gauges, pitches, and the like. Furthermore, when the stitch size varies depending on the knitting width or knitting length, it is preferable to knit a plurality of types of texture samples in a variety of widths and lengths.

Reference Signs List

2: Knit design apparatus
4: Bus
6: Color monitor
8: Manual input device
10: File input/output device
12: Color printer
14: Memory
16: knit design unit
17: Pitch storage unit
18: External shape calculation unit
19: Grid line deforming unit
20: External shape extraction unit
24: Smoothing unit
26: Loop arrangement unit
28: Display control unit
30 to 32: Box
71, 72: Stitch
73: Circle
c1 to c4: Course
w1 to w5: Wale
xp: Standard pitch in wale direction
yp: Standard pitch in course direction

Claims

A knit design system (2) configured to obtain, based on knit design data or knit data, an external size of a knit fabric in which stitches are arrayed in a course direction and a wale direction, characterized in that the knit design system (2) comprises:
a pitch storage unit (17) configured to store two types of array pitches of the stitches, an array pitch in the course direction and an array pitch in the wale direction, such that the array pitch where the same type of stitches are connected to each other and the array pitch where different types of stitches are connected to each other are different from each other;

a grid line deforming unit (19) configured to deform grid lines of an array of stitches in the course direction into the wale direction according to an average of pitches in the wale direction of the stitches belonging to the respective grid lines, and to deform grid lines of an array of stitches in the wale direction into the course direction according to an average of pitches in the course direction of the stitches belonging to the respective grid lines; and

an external shape extraction unit (20) configured to obtain an external shape of the knit fabric based on the deformed grid lines,

the external shape of the knit fabric being obtained by deformation of the grid lines according to the array pitches of the stitches.
The knit design system (2) according to claim 1,
characterized in that the average is a moving average on each of the grid lines, and the average varies depending on positions on the respective grid lines.
The knit design system (2) according to claim 1 or 2,
characterized in that a pitch in the course direction and a pitch in the wale direction when a stitch is moved to a side in the course direction are stored in the pitch storage unit (17), or are calculated using the array pitches stored in the pitch storage unit (17).
The knit design system (2) according to any one of claims 1 to 3,
characterized in that the knit design system (2) further comprises a smoothing unit (24) configured to smooth positions of stitches defined by the deformed grid lines with respect to stitches at an end of the knit fabric.
The knit design system (2) according to any one of claims 1 to 4,
characterized in that the knit design system (2) further comprises a loop arrangement unit (26) configured to arrange images showing stitches in loops of yarns such that the yarns are connected to each other, based on types of stitches, positions of stitches defined by the deformed grid lines, and connection relationship between stitches.
The knit design system (2) according to any one of claims 1 to 5,
characterized in that the knit design system (2) further comprises a display control unit (28) configured to display an image showing a target size of the knit fabric and an image of the knit fabric defined by the deformed grid lines on a color monitor (6) in an overlapping manner, and to accept a change of data for defining design of the knit fabric.
A knit design method for obtaining an external size of a knit fabric in which stitches are arrayed in a course direction and a wale direction based on knit design data or knit data using a knit design system (2), characterized in that the method comprises steps for:
the knit design system (2) storing two types of array pitches of the stitches, an array pitch in the course direction and an array pitch in the wale direction, the array pitch where the same type of stitches are connected to each other and the array pitch where different types of stitches are connected to each other being different from each other;

the knit design system (2) deforming grid lines of an array of stitches in the course direction into the wale direction according to an average of pitches in the wale direction of the stitches belonging to the respective grid lines, and to deform grid lines of an array of stitches in the wale direction into the course direction according to an average of pitches in the course direction of the stitches belonging to the respective grid lines; and

obtaining an external shape of the knit fabric based on the deformed grid lines,

the external shape of the knit fabric being obtained by deformation of the grid lines according to the array pitches of the stitches.