Patent Description:
There is a known technology of measuring a three-dimensional foot shape of a person who is considering purchasing shoes and using the measurement values to analyze whether or not the foot shape fits a shoe (see Japanese Unexamined Patent Application Publication <CIT>; U. Patent Application Publication <CIT>).

In these documents, the foot shape of a subject is compared to a last by comparison with the dimensions of the last. However, the related arts do not disclose a specific method for comparing a foot shape and a last. In general, information on lasts is information to be kept confidential for shoe manufacturers, in which their techniques and know-how are concentrated. Accordingly, information such as the exact dimensions of a last and the design concept, materials, characteristics, and the like of each shoe can only be known by the manufacturer of the shoe. Therefore, even though the comparison between a foot shape and a last is theoretically possible, in reality, it is hard to say that there have been provided means of comparison and fit analysis in which the design concepts and characteristics of shoes and lasts are fully reflected.

Furthermore, <CIT> discloses a method for selecting a shoe, which comprises obtaining electronic data of a foot, comparing the electronic data of a foot with comparative electronic data associated to a plurality of shoes, and selecting a shoe as a function of the comparison. Still further, <CIT> refers to a method for determining well-fitting footware comprises storing a three dimensional (3D) foot image representation defining an exterior contour of a human foot, storing respective 3D footlast representations defining respective interior contours of the footlasts, and determining which one or more of the footlasts has an acceptable fit when one or more respective ones of the interior contours fits about the exterior contour.

Meanwhile, a store such as a shoe store may be staffed with a professional, also called a shoe fitter, who can select shoes that fit a customer's feet, with a wealth of knowledge and skills. Therefore, there has been desired development of technology for selecting shoes more easily and satisfyingly as if a shoe fitter did, without such expertise or skills.

The present disclosure has been made in view of such a situation, and it is an object thereof to provide a technology for improving accuracy of selecting a shoe that fits a foot.

In response to the above issue, the above object is achieved by a shoe fit evaluation device according to claim <NUM> and a shoe fit evaluation method according to claim <NUM>. Alternatively, the above object is achieved by a shoe fit evaluation device according to claim <NUM> and a shoe fit evaluation method according to claim <NUM>.

Further features and advantageous modifications are shown in the dependent claims.

Embodiments will now be described, by way of example only, with reference to the accompanying drawings which are meant to be exemplary, not limiting, and wherein like elements are numbered alike in several FIGURES, in which:.

The disclosure will now be described by reference to the embodiments. This does not intend to limit the scope of the present invention, which is defined in the appended claims, but to exemplify the invention.

In the following, the present disclosure will be described based on embodiments with reference to each drawing. In the embodiments and modifications, like reference characters denote like or corresponding constituting elements, and the repetitive description will be omitted as appropriate.

<FIG> illustrates a basic configuration of a shoe fit evaluation system <NUM>. The shoe fit evaluation system <NUM> mainly includes an information terminal <NUM> and a shoe fit evaluation server <NUM>. The "shoes" herein mainly mean running shoes or walking shoes but may also include other types of shoes. A measurement subject <NUM> scans his or her foot shape using a three-dimensional foot shape measuring device <NUM> installed at a shoe store. Alternatively, the measurement subject <NUM> may place his or her foot on a measurement mat <NUM> and scan his or her own foot shape by capturing an image of the foot with a camera function of the information terminal <NUM> and through measurement with a foot shape measurement application. Alternatively, the foot length and the ball girth of the measurement subject <NUM> may be manually measured using a measuring instrument such as a tape measure <NUM>, and the measurement values may be entered into the information terminal <NUM>. The three-dimensional foot shape measuring device <NUM> acquires three-dimensional data related to the foot shape of the measurement subject <NUM> by laser measurement. The "foot shape" as used herein is a three-dimensional model that virtually reproduces a three-dimensional shape of a foot of the measurement subject <NUM>. The information terminal <NUM> may generate the foot shape of the measurement subject <NUM> by means of a three-dimensional scanner function using a technology such as light detection and ranging (LiDAR) or through image synthesis processing such as photogrammetry.

The shoe fit evaluation system <NUM> may further include the measurement mat <NUM> and the three-dimensional foot shape measuring device <NUM>. The information terminal <NUM> may be operated by the measurement subject <NUM> himself or herself as a user, or the three-dimensional foot shape measuring device <NUM> or the information terminal <NUM> may be used by a person other than the measurement subject <NUM>, such as a salesperson of a shoe store, to perform the foot shape scanning. Therefore, the information terminal <NUM> may be a terminal owned by a shoe store where the three-dimensional foot shape measuring device <NUM> is installed or may be a terminal owned by the measurement subject <NUM> himself or herself.

The measurement values as the result of three-dimensional measurement of a foot shape scanned by the three-dimensional foot shape measuring device <NUM> or the information terminal <NUM> are transmitted from the information terminal <NUM> to the shoe fit evaluation server <NUM>. The "shoe fit evaluation device" in the claims may mean the entire shoe fit evaluation system <NUM> or may mean the shoe fit evaluation server <NUM>. In the present embodiment, the shoe fit evaluation server <NUM> substantially corresponds to the "shoe fit evaluation device" because many of the characteristic functions included in the "shoe fit evaluation device" in the claims are implemented such as to be included in the shoe fit evaluation server <NUM>. The characteristic functions of the "shoe fit evaluation device" may also be distributed between the information terminal <NUM> and the shoe fit evaluation server <NUM> or may also be implemented such that many of them are included in the information terminal <NUM>.

The shoe fit evaluation server <NUM> is a server computer connected to multiple information terminals <NUM> via a network line, such as the Internet or a local area network (LAN), and a communication means, such as wireless communication. The shoe fit evaluation server <NUM> may be constituted by a single server computer or may be constituted by a combination of multiple server computers. The information terminal <NUM> may be a mobile information terminal, such as a smartphone or a tablet terminal, or may be a personal computer.

<FIG> schematically illustrate correspondence relationships between parts in a foot shape of a measurement subject and parts in a last. In the present embodiment, the fit of a foot shape to a shoe as an evaluation target is evaluated based on dimensional differences between multiple foot parts in a foot shape and the corresponding multiple foot parts in a last. <FIG> schematically illustrates a three-dimensional model of a foot shape. <FIG> schematically illustrates a three-dimensional model of a last. The multiple foot parts herein mean the foot length, ball girth, heel width, instep girth, and short heel girth. In the present embodiment, the fit of a foot shape to a shoe is evaluated with reference to the dimensional differences in the foot length and the ball girth and a measurement value of the heel width. In a modification, however, a combination of one or more of the ball girth, heel width, instep girth, and short heel girth and the foot length may be referred to for the evaluation of the fit. In the following, with reference to <FIG>, multiple foot parts including the foot length, ball girth, heel width, instep girth, and short heel girth will be described.

A foot shape <NUM> is a three-dimensional model obtained by scanning the shape of a foot of the measurement subject <NUM> with the three-dimensional foot shape measuring device <NUM> or information terminal <NUM> and virtually reproducing the shape. However, the foot shape <NUM> does not necessarily faithfully reproduce the foot shape, especially the shape near the toes, of the measurement subject <NUM> and is intentionally deformed so as to be easily compared with a last <NUM>. Based on the three-dimensional model of the foot shape thus generated, a foot shape foot length <NUM>, a foot shape ball girth <NUM>, a foot shape instep girth <NUM>, a foot shape short heel girth <NUM>, and a foot shape heel width <NUM> can be measured. The foot shape foot length <NUM>, foot shape ball girth <NUM>, foot shape instep girth <NUM>, foot shape short heel girth <NUM>, and foot shape heel width <NUM> are parts corresponding respectively to the foot length, ball girth, instep girth, short heel girth, and heel width of the foot of the measurement subject <NUM>.

A last <NUM> is a three-dimensional model that virtually reproduces one of lasts of multiple types of shoes prepared in advance as options for shoes to be recommended. For shoes, multiple types of products are prepared, and even a single type of product model may be available in sizes corresponding to multiple foot lengths and multiple foot widths. Further, different shapes may be prepared for men and women. For each of the many types of shoes, a different last is used. A last is a mold assumed to be an ideal foot shape for each shoe model and is actually used as a mold in the shoe manufacturing process. In the shoe manufacturing process, a shoe is manufactured such that the upper and sole are bonded together such as to wrap around a last before the last is taken out. In the shape and size of the last for each shoe model or in the stretch properties and allowance of the shoe set for each part of the last, the design concept for the product and know-how is reflected, so that such information is not usually disclosed outside the shoe manufacturer. A reference value for fit judgment based on such design concept and know-how is set in advance in the shoe fit evaluation server <NUM>, which will be described later.

In the three-dimensional model of a last, values indicating a last foot length <NUM>, a last ball girth <NUM>, a last instep girth <NUM>, a last short heel girth <NUM>, and a last heel width <NUM> are prepared in advance. The last foot length <NUM>, last ball girth <NUM>, last instep girth <NUM>, last short heel girth <NUM>, and last heel width <NUM> are parts corresponding respectively to the foot shape foot length <NUM>, foot shape ball girth <NUM>, foot shape instep girth <NUM>, foot shape short heel girth <NUM>, and foot shape heel width <NUM>. Therefore, a foot length dimensional difference is calculated between the foot shape foot length <NUM> and the last foot length <NUM>, and a ball girth dimensional difference is calculated between the foot shape ball girth <NUM> and the last ball girth <NUM>. Also, an instep girth dimensional difference may be calculated between the foot shape instep girth <NUM> and the last instep girth <NUM>, a short heel girth dimensional difference may be calculated between the foot shape short heel girth <NUM> and the last short heel girth <NUM>, and a heel width dimensional difference may be calculated between the foot shape heel width <NUM> and the last heel width <NUM>.

<FIG> is a functional block diagram that shows each configuration in the shoe fit evaluation system <NUM>. The shoe fit evaluation system <NUM> in the present embodiment is constituted by the information terminal <NUM> and the shoe fit evaluation server <NUM>. The shoe fit evaluation system <NUM> may be implemented by various hardware configurations and software configurations. For example, the shoe fit evaluation system <NUM> may be constituted only by the shoe fit evaluation server <NUM> or may be constituted only by the information terminal <NUM>.

With regard to each of the information terminal <NUM> and the shoe fit evaluation server <NUM>, <FIG> shows functional blocks implemented by coordination of various hardware configurations and software configurations. Therefore, it will be understood by those skilled in the art that these functional blocks may be implemented in a variety of forms by hardware only, software only, or a combination thereof. The information terminal <NUM> is constituted by a combination of hardware, such as a camera module, range sensor, microprocessor, touch panel, memory, and communication module. The information terminal <NUM> may be a general-purpose information terminal, such as a smartphone or tablet terminal, prepared by the measurement subject <NUM> or a shoe store. By equipping the information terminal <NUM> with a program having the following functions or by accessing a website provided by the shoe fit evaluation server <NUM> via a web browser, the information terminal <NUM> substantially performs the following functions by cooperation between software and hardware. The information terminal <NUM> includes, as its functions, an optical information acquirer <NUM>, a scanning processing unit <NUM>, an operation input unit <NUM>, a model generator <NUM>, an information generator <NUM>, a part measurer <NUM>, a display unit <NUM>, and a communication unit <NUM>.

When a three-dimensional model is generated using a LiDAR technology, the optical information acquirer <NUM> is constituted by a LiDAR sensor in terms of hardware. In this case, the optical information acquirer <NUM> detects laser light, and the scanning processing unit <NUM> scans a three-dimensional shape of a foot of the measurement subject <NUM> by measuring the distance to the object based on the information acquired from the optical information acquirer <NUM>. Based on the information obtained through the scanning by the scanning processing unit <NUM>, the model generator <NUM> generates a three-dimensional model of the foot shape.

When a three-dimensional model is generated using a photogrammetry technology, the optical information acquirer <NUM> is constituted by a camera module in terms of hardware. In this case, the optical information acquirer <NUM> captures an image of a foot of the measurement subject <NUM> from the surroundings, and the scanning processing unit <NUM> scans a three-dimensional shape of the foot of the measurement subject <NUM> by acquiring a moving image or a number of still images as images of the foot. Based on the information obtained through the scanning by the scanning processing unit <NUM>, the model generator <NUM> generates a three-dimensional model of the foot shape.

When a three-dimensional model is generated using the three-dimensional foot shape measuring device <NUM>, the model generator <NUM> acquires information obtained through scanning by the three-dimensional foot shape measuring device <NUM> via the communication unit <NUM> and generates a three-dimensional model of the foot shape based on the information thus acquired.

The part measurer <NUM> measures the foot shape foot length <NUM>, foot shape ball girth <NUM>, foot shape instep girth <NUM>, foot shape short heel girth <NUM>, and foot shape heel width <NUM> in the three-dimensional model generated by the model generator <NUM>. The information generator <NUM> generates screen display contents for displaying the three-dimensional model generated by the model generator <NUM> and the measurement values measured by the part measurer <NUM> on the screen of the information terminal <NUM>. The information generator <NUM> also generates information on the three-dimensional model and the measurement values, identification information and attribute information for identifying the measurement subject <NUM>, information for identifying the shoe preferences and wishes of the measurement subject <NUM>, and the like and transmits such information to the shoe fit evaluation server <NUM> via the communication unit <NUM>. The display unit <NUM> displays the display contents generated by the information generator <NUM> and display contents received from the shoe fit evaluation server <NUM>, on the screen of the information terminal <NUM>.

The shoe fit evaluation server <NUM> is constituted by a combination of hardware, such as a microprocessor, memory, display, and communication module. The shoe fit evaluation server <NUM> may be a server computer constructed and managed by a shoe manufacturer. On the shoe fit evaluation server <NUM>, a program having the following functions runs. The shoe fit evaluation server <NUM> includes, as its functions, a communication unit <NUM>, a measurement value acquirer <NUM>, a storage unit <NUM>, a fit evaluation unit <NUM>, and an output unit <NUM>. The communication unit <NUM> of the information terminal <NUM> and the communication unit <NUM> of the shoe fit evaluation server <NUM> are connected via a network <NUM>.

The measurement value acquirer <NUM> acquires, from the information terminal <NUM> via the communication unit <NUM>, the measurement values of multiple foot part dimensions, which are dimensions of multiple foot parts including at least the foot length, as foot shape dimension information that defines a foot shape of the measurement subject <NUM>. Although the measurement value acquirer <NUM> of the present embodiment acquires the measurement values of the foot length, ball girth, and heel width, in a modification, the measurement values of any one or more or all of the ball girth, instep girth, short heel girth, and heel width in combination with the foot length may be acquired.

The storage unit <NUM> includes a user storage unit <NUM>, a last storage unit <NUM>, and a shoe information storage unit <NUM>. The user storage unit <NUM> stores the identification information and attribute information for identifying the measurement subject <NUM>, transmitted from the information terminal <NUM>. The last storage unit <NUM> stores, for each of multiple types of lasts, multiple last part dimensions, which are dimensions of last parts corresponding to multiple foot parts including at least the foot length, as last dimension information that defines a last. Although the last storage unit <NUM> of the present embodiment stores, as the multiple last part dimensions, the dimensions of the last foot length and the last ball girth for each last, in a modification, the dimensions of any one or more or all of the last ball girth, last instep girth, last short heel girth, and last heel width in combination with the last foot length may be stored. The shoe information storage unit <NUM> stores information on multiple models and multiple sizes of shoes. The multiple models include men's models and women's models. The shoe sizes include multiple foot length sizes and multiple foot width sizes. The shoe information includes various adjustment values, which will be detailed later, set in advance for each last or each shoe.

The fit evaluation unit <NUM> includes a last selector <NUM>, a dimensional difference calculation unit <NUM>, and an evaluation processing unit <NUM>. The last selector <NUM> selects, as an evaluation target, any one or more lasts from among multiple types of lasts stored in the last storage unit <NUM>. For example, based on preference information and measurement values of foot dimensions entered by the operator of the information terminal <NUM>, the last selector <NUM> selects one or more lasts as evaluation targets, from among lasts of shoes that can be worn with a foot of the foot dimensions and lasts of which sizes approximate the foot dimensions. In order to select the most suitable shoe for the foot of the measurement subject <NUM> from among a wide range of options, it is desirable that the last selector <NUM> selects multiple lasts as the evaluation targets. In a modification, instead of the multiple lasts selected in advance as the evaluation targets by the last selector <NUM>, substantially all lasts stored in the last storage unit <NUM> may be set as the evaluation targets. In such a case, the dimensional difference calculation unit <NUM> and the evaluation processing unit <NUM> calculate a part dimensional difference and a last matching rate for each of all lasts as the evaluation targets. Conversely, in the present embodiment, in order to avoid the calculation of the part dimensional difference and the last matching rate for all lasts, the evaluation targets are narrowed down to some extent particularly based on the measurement values of the foot length and the ball girth and on the preferences and attributes of the measurement subject <NUM> before the part dimensional difference and the last matching rate are calculated, so as to reduce the calculation load. A dimensional difference between a last selected by the last selector <NUM> and a foot shape acquired by the measurement value acquirer <NUM> is calculated as follows.

The dimensional difference calculation unit <NUM> calculates a part dimensional difference, which is a difference between the measurement value of a foot part dimension and a last part dimension corresponding to the foot part, in which a predetermined adjustment for the part is performed. The evaluation processing unit <NUM> calculates the last matching rate based on the part dimensional difference. In the following, methods for calculating the part dimensional difference and the last matching rate will be detailed.

As described previously, the part dimensional difference in the present embodiment includes the dimensional difference between the measurement value of the foot length in a foot shape and the last foot length, and the dimensional difference between the measurement value of the ball girth in the foot shape and the last ball girth. In a modification, however, a combination of the part dimensional difference of at least one of the instep girth, short heel girth, or heel width and the part dimensional difference of the foot length may be used.

The "predetermined adjustment" includes the following four calculations. That is, in the calculation of the part dimensional difference, there are an adjustment to subtract an allowance for the specific stretch properties of each shoe part (Adjustment <NUM>), an adjustment to calculate the part dimensional difference as the sum of the squares of part dimensional differences in which the specific weights of the respective parts are added (Adjustment <NUM>), an adjustment to calculate the sum of the squares of part dimensional differences in which a first weight is added to the part dimensional difference of the foot length and a second weight, which is smaller than the first weight, is added to the part dimensional difference of a part other than the foot length (Adjustment <NUM>), and an adjustment to use, as a measurement value of a foot part dimension, a value obtained by adding, to the actual measured value of the foot part dimension, an error correction depending on the measurement method (Adjustment <NUM>). The method for calculating the last matching rate with these adjustments added is given by the following equation.

The part dimensional difference as used herein is the sum of the squares of the foot length dimensional difference and the ball girth dimensional difference and is given by the following equation.

The "foot length score" is a value obtained by squaring the foot length dimensional difference, and the "ball girth score" is a value obtained by squaring the ball girth dimensional difference. The foot length dimensional difference is the dimensional difference between the last foot length and the measurement value of the foot length, and the ball girth dimensional difference is the dimensional difference between the last ball girth and the measurement value of the ball girth. However, since each shoe part may have specific stretch properties, the foot length dimensional difference and the ball girth dimensional difference are calculated such that allowances for such stretch properties are subtracted (Adjustment <NUM>). Therefore, the foot length score and the ball girth score are given by the following equations. <MAT> <MAT>.

The upper may be formed to have relatively low stretchability in the foot length directions of the shoe and may be formed to have relatively high stretchability in the ball girth directions of the shoe. For example, d1, which is an adjustment value in the foot length directions, may be set to a small value of <NUM> or less. Also, d2 may be set to a large value of several millimeters or more, which corresponds to <NUM>-<NUM>% of the ball girth, so as to allow a wearer to select slightly tight shoes at least at the time of purchase, in anticipation of stretching and contracting to some extent in the ball girth directions, for example. Therefore, the values of d1 and d2 may be set so that d1 < d2 holds. Also, each of d1 and d2 may be set to a negative value. Also, d1 and d2 may be set for each last, i.e., for each shoe model or size. Further, d1 and d2 may be set to pre-adjusted values so that the results are equivalent to those obtained when a shoe fitter selects shoes.

Lasts are not necessarily made to perfectly reproduce the shape of a human foot, and a last may be sometimes intentionally made to have a characteristic shape that differs from the shape of a human foot, for a design concept for enhancing the functionality of the shoe. Also, in many designs, a margin called "toe room" is provided as a toe space so as to prevent the toe from frequently coming into contact with an inner tip portion of the shoe during walking. In the case of shoes for trail runners who run on uneven ground or undulating road surfaces, a shoe with larger toe room than a normal shoe may be preferred to prevent frequent contact of the toe with the shoe. Also, the material or thickness of the upper may differ depending on the category or model of the shoe. Thus, since such differences based on the design concept and shoe characteristics can be considered in advance also for the part dimensional difference, d1 and d2 may be set as the adjustment values based on such design differences.

The part dimensional difference is calculated as the sum of the squares of part dimensional differences with weights α and β specific to the respective parts added (Adjustment <NUM>). More specifically, the foot length score is multiplied by the weighting factor α, and the ball girth score is multiplied by the weighting factor β. When the fit of a shoe is measured, the foot length is considered to be the most influential factor among multiple foot parts. Therefore, also when the last matching rate is calculated, a relatively large weight is given in the evaluation of the foot length, and a relatively small weight is given in the evaluation of the ball girth (Adjustment <NUM>). The weighting factor α may be set to <NUM> to <NUM>, and the weighting factor β may be set to <NUM> to <NUM>, which is smaller than the weighting factor α. For example, when the weighting factor α is set to <NUM>, the weighting factor β is set to <NUM>; when the weighting factor α is set to <NUM>, the weighting factor β is set to <NUM>. The weighting factors α and β are stored in the shoe information storage unit <NUM> and may be set to different values for each shoe model or size. Further, the weighting factors α and β may be set to pre-adjusted values so that the results are equivalent to those obtained when a shoe fitter selects shoes. As a modification, the instep girth score, short heel girth score, and heel width score may be further calculated based on the instep girth dimensional difference, short heel girth dimensional difference, and heel width dimensional difference, and the square value in each of these scores may be given a specific weight to calculate the part dimensional difference.

As a measurement value of each foot part, a value obtained by adding an error correction depending on the measurement method to the actual measured value of the foot part dimension is used (Adjustment <NUM>). For example, when the last dimensions to be stored in the last storage unit <NUM> are designed to be obtained by manually measuring the foot part dimensions using a measuring instrument such as the tape measure <NUM>, an error may occur between measurement by the three-dimensional foot shape measuring device <NUM> or the information terminal <NUM> by means of laser ranging and the manual measurement. For example, it is considered that the measurement values of laser ranging are slightly smaller. Therefore, when the measurement values are not manually measured, values obtained by adding an error correction of about <NUM> to <NUM>, for example, to each of the actual measured values of the foot length dimension and the ball girth dimension may be used as the measurement values of the foot part dimensions, in order to match the design concept of the last. Also, in the case of manual measurement, the error correction of the ball girth dimension may be made larger than the error correction of the foot length dimension, in order to reflect the feature by which, compared to the measurement of the foot length, the ball girth is likely to be smaller than the actual ball girth by being measured with the tape measure placed tighter.

When the ratio of the actual measured value of the heel width dimension to the actual measured value of the foot length dimension, which is referred to a heel width ratio, is greater than or equal to a predetermined ratio (e.g., around <NUM>/<NUM>), it is assumed that the upper limit of the ideal heel width of the last is exceeded, and the heel of the foot is less likely to fit properly in the heel portion of a shoe made with the last. In such a case, since the heel does not fit in the shoe, the foot will easily move forward during walking or the like, which may cause the shoe to feel tight because there is no room in the toe space. Therefore, when the heel width is a predetermined ratio or greater, a value obtained by adding a predetermined size up adjustment value (<NUM> to <NUM>, for example) to the actual measured value of the foot length dimension may be used as the measurement value of the foot length dimension, for the purpose of recommending the shoe in the next size up. The error correction and the size up adjustment value are stored in the shoe information storage unit <NUM> and may be set to different values for each shoe model or size. Also, the error correction and the size up adjustment value may be set to pre-adjusted values so that the results are equivalent to those obtained when a shoe fitter selects shoes.

The evaluation processing unit <NUM> calculates the last matching rate for each of multiple types of lasts as the evaluation targets. The evaluation processing unit <NUM> selects at least one shoe corresponding to a last having a relatively high last matching rate, from among multiple shoe options. Thus, by calculating the last matching rate based on the part dimensional difference obtained as a result of comparison between the measurement values of foot parts and last parts and by selecting the most suitable shoe based on the last matching rate, a shoe with an inner shape that has a high degree of conformity with the foot shape can be selected. Since the last matching rate is calculated based on the last part dimensions and numerical values in which characteristics of each shoe or each last are accurately reflected, the accuracy of selecting a shoe that fits a foot can be improved. Also, since various adjustment values can be set for each shoe or each last, a shoe selection method in which the expertise and know-how of shoe fitters is reflected can be reproduced more faithfully.

The output unit <NUM> transmits information regarding the last matching rate to the information terminal <NUM> via the communication unit <NUM> so as to display shoe recommendation information including the last matching rate on the screen of the information terminal <NUM>. The output unit <NUM> includes a recommendation output unit <NUM> and a comparison output unit <NUM>. The recommendation output unit <NUM> outputs, as recommendation information, information that indicates a shoe selected by the evaluation processing unit <NUM> and the last matching rate of the last of the shoe. The comparison output unit <NUM> outputs information that visually indicates a comparison result between a last part dimension of a shoe selected by the evaluation processing unit <NUM> and a foot part dimension. Examples of screen display of the recommendation information and comparison result will be detailed later.

<FIG> is a flowchart that shows the process of shoe fit evaluation processing. When the shoe fit evaluation processing is started, the measurement value acquirer <NUM> acquires measurement values of foot part dimensions (S10), and the last selector <NUM> selects a last as an evaluation target (S12). The dimensional difference calculation unit <NUM> recognizes the measurement method used for the measurement of the foot part dimensions (S14) and adjusts the measurement values of the foot part dimensions for error correction depending on the measurement method (S16). The dimensional difference calculation unit <NUM> adjusts the part dimensional difference according to the characteristics of each part (S18), and the evaluation processing unit <NUM> calculates the last matching rate based on the part dimensional difference (S20). The recommendation output unit <NUM> outputs information on the shoe and the last matching rate (S22), the comparison output unit <NUM> outputs comparison information on the foot shape and the last (S24), and the shoe fit evaluation processing is terminated. The processes from S10 to S24 may be performed in various orders, and the order of S10 to S24 in the flowchart of <FIG> is merely an order determined for convenience. Also, the process from the last selection processing at S12 to the output processing at S22 and S24 may be repeated while the shoe as the evaluation target is replaced, until the most suitable shoe for the measurement subject <NUM> is found.

<FIG> illustrates a screen example for shoe recommendation information. On a screen <NUM> displayed on the information terminal <NUM>, recommendation information generated by the recommendation output unit <NUM> based on a shoe selected by the evaluation processing unit <NUM> and the last matching rate is displayed. The screen <NUM> is mainly constituted by a first tab screen <NUM>, a second tab screen <NUM>, a third tab screen <NUM>, and a fourth tab screen <NUM>, and a tab screen selected by the operator from among the first tab screen <NUM>, second tab screen <NUM>, third tab screen <NUM>, and fourth tab screen <NUM> is displayed. For example, the category "PROTECT" on the first tab screen <NUM> corresponds to shoes for a wide range of runners, from beginners aiming to complete a marathon to everyday runners. The category "ENERGY" on the second tab screen <NUM> corresponds to shoes for runners of various levels who want to run longer and comfortably. The category "SPEED" on the third tab screen <NUM> corresponds to shoes for runners who pursue speed, such as athletes and advanced marathon runners. The category "TRAIL" on the fourth tab screen <NUM> corresponds to shoes for trail runners who run on uneven ground or undulating road surfaces. By selecting one of the tab screens, the operator can select a preferred shoe category.

On the screen <NUM> shown in <FIG>, pieces of information for recommending four types of shoes as the shoes corresponding to the category "PROTECT" are displayed respectively in a first recommendation column <NUM>, a second recommendation column <NUM>, a third recommendation column <NUM>, and a fourth recommendation column <NUM>. For example, in the first recommendation column <NUM>, a shoe image <NUM>, a product name <NUM>, size information <NUM>, a last matching rate <NUM>, a comparison button <NUM>, and a detail button <NUM> are displayed. The shoe image <NUM> visually shows the appearance of a recommended shoe. The product name <NUM> is a model name of the shoe, such as "GK-<NUM> WOMEN WIDE", and includes an identification name to distinguish whether the model is for men or women and which foot width model it is. The size information <NUM> is a character string indicating the last foot length, such as "<NUM>". However, since the length unit used for a product model varies, such as centimeters and inches, it is not required that the length is exactly the same as the actual last foot length.

As the last matching rate <NUM>, the numerical value of the last matching rate calculated by the evaluation processing unit <NUM> is displayed in the form of a character string, such as "matching <NUM>%". The comparison button <NUM> is a link button to a comparison page for comparing a foot shape and a last, and, when the operator presses the comparison button <NUM>, the screen switches to the comparison page between the foot shape and the last. The detail button <NUM> is a link button to a product introduction page for introducing the details of the shoe model recommended in the first recommendation column <NUM>, and, when the operator presses the detail button <NUM>, the screen switches to the product introduction page.

As in the first recommendation column <NUM>, also in each of the second recommendation column <NUM>, third recommendation column <NUM>, and fourth recommendation column <NUM>, the shoe image, product name, size information, last matching rate, comparison button, and detail button are displayed. Thus, the last matching rate for each recommended shoe model is presented, so that the user can compare the products with each other and consider a purchase based thereon.

<FIG> illustrates a first example of a comparison page for a foot shape and a last. On a screen <NUM> displayed on the information terminal <NUM>, left and right foot shape images <NUM> are displayed, and left and right shoe images <NUM> are also displayed such as to overlap the foot shape images <NUM>. In <FIG>, the outline of each shoe is indicated as a shoe image <NUM> with a dotted line, for the sake of convenience. However, in order to make a difference in positional relationship or size between a foot shape image <NUM> and a shoe image <NUM> clearer, an actual shoe image may be displayed in a translucent manner and superimposed on the foot shape image <NUM>.

A left foot length difference area <NUM> is an area displayed to indicate a margin in the foot length directions of the left foot, and a pattern or color indicating that the left foot length dimension difference is appropriate is applied to the area. As a left foot length fit display <NUM>, which indicates the magnitude of the left foot length dimension difference in words, the character string of "RECOMMENDED" is displayed to indicate that the left foot length dimension difference is appropriate.

A right foot length difference area <NUM> is an area displayed to indicate a margin in the foot length directions of the right foot, and a pattern or color indicating that the right foot length dimension difference is too small is applied to the area. As a right foot length fit display <NUM>, which indicates the magnitude of the right foot length dimension difference in words, the character string of "TIGHT" is displayed to indicate that the right foot length dimension difference is too small.

A left ball girth difference area <NUM> is an area displayed to indicate a margin in the ball girth directions of the left foot, and a pattern or color indicating that the left ball girth dimension difference is slightly large is applied to the area. As a left ball girth fit display <NUM>, which indicates the magnitude of the left ball girth dimension difference in words, the character string of "LOOSE" is displayed to indicate that the left ball girth dimension difference is slightly large.

A right ball girth difference area <NUM> is an area displayed to indicate a margin in the ball girth directions of the right foot, and a pattern or color indicating that the right ball girth dimension difference is too small is applied to the area. As a right ball girth fit display <NUM>, which indicates the magnitude of the right ball girth dimension difference in words, the character string of "TIGHT" is displayed to indicate that the right ball girth dimension difference is too small.

As described above, by visually expressing differences between a foot shape and a last with words, colors, patterns, and the like, whether or not the shoe fits the foot can be intuitively grasped by the measurement subject <NUM>.

<FIG> illustrates a second example of a comparison page for a foot shape and a last. On a screen <NUM> displayed on the information terminal <NUM>, left and right foot shape images <NUM> are displayed in the form of three-dimensional models, and last images <NUM> are also displayed in the form of three-dimensional wire frames around the foot shape three-dimensional models. In other words, the foot shapes of the measurement subject <NUM> are displayed three-dimensionally as if they were wearing recommended shoes. As recommendation information <NUM>, a character string indicating the size of the foot length, such as "<NUM>", and a character string indicating the foot width type, such as "WIDE", are displayed. Also, the numerical value of the last matching rate may be further displayed.

As described above, by visually expressing a difference or the fit between a foot shape and a last in three-dimensional space, whether or not the shoe fits the foot can be intuitively grasped by the measurement subject <NUM>.

The second embodiment differs from the first embodiment in that the fit is calculated with further reference to the instep girth, toe shape, and short heel girth, besides the measurement values of the foot length, ball girth, and heel width, as the reference values used for evaluation of the fit of a foot shape to a shoe. Also, in the second embodiment, the fit of a foot shape is calculated for a shoe selected by the user, which differs from the first embodiment in which a shoe that fits a foot shape is extracted and presented to the user. In the following, description will be given mainly for the differences from the first embodiment, and the description of features in common will be omitted.

<FIG> is a flowchart that shows the process of the shoe fit evaluation processing in the second embodiment. In the second embodiment, measurement values of a foot shape of the measurement subject <NUM> acquired by the three-dimensional foot shape measuring device <NUM> or the like are transmitted to the shoe fit evaluation server <NUM> and stored in association with identification information of the measurement subject <NUM> in the shoe fit evaluation server <NUM> in advance. In a modification, measurement values of a foot shape of the measurement subject <NUM> may not be acquired in advance by the three-dimensional foot shape measuring device <NUM> or the like. In that case, the user himself or herself may enter information on the foot length and the ball girth as the measurement values of the foot shape by text entry or the like, and the information thus entered may be stored as the measurement values of the foot shape in association with the user's identification information in the shoe fit evaluation server <NUM>. Alternatively, the measurement values of a foot shape or information on the foot length and the ball girth entered by the user himself or herself may not be stored in association with the identification information in the shoe fit evaluation server <NUM>; when a shoe size suitable for the user's foot and the last matching rate thereof are calculated, the user may enter the information on the foot length and the ball girth, and the information may be used for the calculation.

When a user accesses an online shoe sales site, a list of shoes for sale is displayed (S30). When the user selects, from the shoe list, a shoe model to consider purchasing (S32), a product detail page of the selected shoe is displayed (S34). On the product detail page of the shoe, an image and detailed information of the shoe is presented, and shoe size options are also displayed. When the user has already logged in to the shoe sales site (Y at S36) and when measurement values of the user's foot have been measured and stored in the shoe fit evaluation server <NUM> in advance (Y at S38), the processes from S39 to S48 are performed. That is, the last selector <NUM> selects, as evaluation targets, one or more lasts of which the last foot length is close to the user's foot length, from among lasts of multiple types of shoe sizes corresponding to a shoe model that the user is considering purchasing (S39). The dimensional difference calculation unit <NUM> recognizes the measurement method used for the measurement of the foot part dimensions of the user (S40) and adjusts the measurement values of the foot part dimensions for error correction depending on the measurement method (S42). The dimensional difference calculation unit <NUM> adjusts the part dimensional difference according to the characteristics of each part (S44), and the evaluation processing unit <NUM> calculates the last matching rate based on the part dimensional difference (S46). The recommendation output unit <NUM> displays a shoe size of which the last matching rate is highest, and the last matching rate (S48).

When the user has not logged in to the shoe sales site (N at S36) or when measurement values of the foot have not been measured in advance (N at S38), the processes from S39 to S48 are skipped. In the example described above, when the user has already logged in, the user selects a shoe model from a shoe list, as in S32, and a shoe size of which the last matching rate is high and the last matching rate are then displayed on the product detail page of the shoe. In a modification, the last matching rate for each shoe model may be calculated as shown in S36 to S48 prior to the display of a shoe list at S32; at the stage of the display of a shoe list at S32, a shoe size of which the last matching rate is high and the last matching rate may be displayed for each shoe model.

<FIG> illustrates a screen example for a first product detail page in the second embodiment. The first product detail page is a product detail page displayed when the user is not logged in to the product sales site. On a screen <NUM>, detailed information of a shoe is displayed, and a link button <NUM> showing "LOGIN / MEMBER REGISTRATION" is also displayed at the upper right of the screen <NUM>. The link button <NUM> is linked to a page for login or member registration and indicates that the user viewing the product detail page has not yet logged in or signed up as a member. When the user presses the link button <NUM>, the screen shifts to the page for login or member registration.

On the first product detail page, besides the product name, a product image, and detailed description, evaluation information for the product is also displayed on the screen <NUM>. As shoe color options, multiple color selection buttons are displayed. When one of the color selection buttons is pressed, the pressed selection button is highlighted as a selected state, and a shoe image of the selected color is displayed. Also, the type of the width size of the displayed shoe is displayed in a width size display column <NUM>.

In a shoe size selection column <NUM>, multiple size buttons are displayed as multiple shoe size options. When one of the size selection buttons is pressed, the pressed selection button is highlighted as a selected state. A size recommendation column <NUM> is a column in which a shoe size suitable for the user's foot and the last matching rate thereof are displayed. However, since the measurement values of a foot of a user who is not logged in are unknown, the shoe size suitable for the user's foot and the last matching rate thereof are not displayed.

<FIG> illustrates a screen example for a second product detail page in the second embodiment. The second product detail page is a product detail page displayed when the user has already logged in to the product sales site. As with the screen <NUM> of the first product detail page shown in <FIG>, the screen <NUM> displays the detailed information of a shoe. However, at the upper right of the screen <NUM>, the link button <NUM> is not displayed, but instead a link button <NUM> showing the user name and the character string "LOGOUT" is displayed. The link button <NUM> is linked to a page for logout and indicates that the user viewing the product detail page has already logged in.

When the user has already logged in, the last matching rate is calculated with the measurement values of the user's foot based on the part dimensional difference between the user's foot and lasts of multiple shoe sizes. When the shoe size with the highest last matching rate is "<NUM>", for example, the selection button indicating "<NUM>" is displayed in a different color from the other buttons in the shoe size selection column <NUM>, suggesting that it is most suitable for the user's foot. In the size recommendation column <NUM>, character strings are displayed to indicate that the shoe size most suitable for the user's foot is "<NUM>" and that the last matching rate is "<NUM>%". Also, in an other size information column <NUM> displayed below the size recommendation column <NUM>, the last matching rates for the shoe sizes one size larger and one size smaller are displayed as information regarding other shoe sizes.

<FIG> is a functional block diagram that shows each configuration in the shoe fit evaluation system <NUM> in the second embodiment. The storage unit <NUM> in the second embodiment further includes a measurement value storage unit <NUM> in which measurement values of multiple foot part dimensions acquired from the information terminal <NUM> are stored in association with the identification information of the measurement subject <NUM>.

The last selector <NUM> selects, as an evaluation target, one or more lasts corresponding to a shoe model selected by the user, from among multiple types of lasts stored in the last storage unit <NUM>. Based on the measurement values of the user's foot dimensions, the last selector <NUM> selects one or more lasts as evaluation targets, from among lasts of shoe sizes and width sizes that can be worn with a foot of the foot dimensions and lasts of which sizes approximate the foot dimensions. The lasts are designed and stored respectively for multiple sizes of multiple models. The multiple sizes include multiple shoe sizes as the sizes in the foot length directions, and multiple width sizes as the sizes in the foot width directions. One or more width sizes are designed for one shoe size. Whether or not multiple width sizes are designed for one shoe size depends on the shoe model.

With regard to a last selected by the last selector <NUM>, the dimensional difference calculation unit <NUM> calculates a part dimensional difference, which is a difference between the measurement value of a foot part dimension and a last part dimension corresponding to the foot part, in which a predetermined adjustment for the part is made. The evaluation processing unit <NUM> calculates the last matching rate based on the part dimensional difference for the last selected by the last selector <NUM>. In the following, methods for calculating the part dimensional difference and the last matching rate in the second embodiment will be detailed.

The "predetermined adjustment" includes the following four calculations as in the first embodiment. That is, in the calculation of the part dimensional difference, there are an adjustment to subtract an allowance for the specific stretch properties of each part of a shoe upper (Adjustment <NUM>), an adjustment to calculate the part dimensional difference as the sum of the squares of part dimensional differences in which the specific weights of the respective parts are added (Adjustment <NUM>), an adjustment to calculate the sum of the squares of part dimensional differences in which a first weight is added to the part dimensional difference of the foot length and a second weight, which is smaller than the first weight, is added to the part dimensional difference of a part other than the foot length (Adjustment <NUM>), and an adjustment to use, as a measurement value of a foot part dimension, a value obtained by adding, to the actual measured value of the foot part dimension, an error correction depending on the measurement method (Adjustment <NUM>). The method for calculating the last matching rate with these adjustments added is given by the following equation.

The "specific stretch properties of each part" as used herein mean the properties of the shoe upper's stretching and contracting. The upper is made of mesh or artificial leather, for example, and the rigidity is different in each part. Accordingly, the stretch properties of each part based on the materials and structure of the upper are taken into consideration in the calculation of the part dimensional difference. Even two shoes manufactured with the same last will differ in stretch properties if the materials or structures of their uppers are different. Therefore, Adjustment <NUM> may be performed depending on the difference in stretch properties, as necessary.

Also, with regard to the "specific weights", since the rigidity distribution in the shoe upper is not necessarily constant for each shoe model, the specific weights are used to weight the calculated values, as Adjustment <NUM>, in order to adjust the influence of each part on the last matching rate.

In the second embodiment, among the predetermined adjustments (Adjustments <NUM> to <NUM>) for foot parts in the calculation of the part dimensional difference, Adjustment <NUM> using a value obtained by adding an error correction depending on the measurement method may be performed in advance, and the adjusted values after Adjustment <NUM> may be stored as the measurement values of the foot part dimensions of the user in the measurement value storage unit <NUM>. In that case, since Adjustment <NUM> has already been performed on the measurement values stored in the measurement value storage unit <NUM>, Adjustment <NUM> is not performed when a last suitable for the user's foot is evaluated for a shoe model selected by the user.

In the second embodiment, the dimensional difference calculation unit <NUM> and the evaluation processing unit <NUM> calculate a size score and a width score to calculate the last matching rate based on the part dimensional difference. The part dimensional difference is the sum of the squares of the size score based mainly on the foot length dimensional difference and the width score based mainly on the ball girth dimensional difference and is given by the following equation.

In the equation, "α" is a weighting factor by which the size score is multiplied and corresponds to the "first weight" in the first embodiment and the claims. Also, "β" is a weighting factor by which the width score is multiplied and corresponds to the "second weight" in the first embodiment and the claims. The size score substantially corresponds to the "foot length score" in the first embodiment. Also, the width score substantially corresponds to the "ball girth score" in the first embodiment.

The size score is a value calculated based on the measurement results of the foot length, heel width, short heel girth, and toe shape and is given by the following equation.

The adjustment value d1 is an adjustment value used when Adjustment <NUM> is applied to the foot length dimensional difference, similarly to Adjustment <NUM> in the first embodiment. The adjustment value d1 is an allowance subtracted from the foot length dimensional difference, based on the specific stretch properties of each shoe part.

The correction value C1 corresponds to the "size up adjustment value" described in the first embodiment and is one of (<NUM>) a correction value based on the heel width ratio, (<NUM>) a correction value based on a short heel girth ratio, or (<NUM>) a correction value based on the toe shape, or a value obtained by adding these correction values. The correction value C1 is a variable value, as which a different value is set also depending on the width type of a last as an evaluation target for the part dimensional difference. The "heel width ratio" is a ratio of the heel width to the foot length, i.e., heel width ratio = heel width / foot length, and is usually around <NUM>/<NUM> to <NUM>/<NUM>. The "short heel girth ratio" is a ratio of the short heel girth to the foot length, i.e., short heel girth ratio = short heel girth / foot length, and is usually a ratio of <NUM>% or higher.

(<NUM>) The foot length dimensional difference is adjusted based on the heel width ratio because, since the heel of a foot with a larger heel width ratio is more difficult to fit into a heel portion of a shoe, the entire foot shifts toward the toe, so that the shoe is likely to be tight at the toe. (<NUM>) The foot length dimensional difference is adjusted based on the short heel girth ratio because, as with the heel width ratio, since the heel of a foot with a larger short heel girth ratio is more difficult to fit into a heel portion of a shoe, the entire foot shifts toward the toe, so that the shoe is likely to be tight at the toe. (<NUM>) The foot length dimensional difference is adjusted based on the toe shape because, especially when the toe shape is a square type, the fourth and fifth toes are difficult to fit into a toe portion of a shoe. The toe shape includes a round type characterized by a long second toe, an oblique type characterized by a long first toe, and a square type characterized by little difference in toe length. The square type is particularly common in children's feet. The type of toe shape can be determined by evaluating the ratio of the length or tip position of each of the first to fifth toes to the foot length.

Since (<NUM>) the correction value based on the heel width ratio and (<NUM>) the correction value based on the short heel girth ratio have a feature in common of having the reason for adjustment of the fit of the heel, there is no need to perform the adjustment doubly, and the larger correction value is preferentially used for the adjustment. Meanwhile, (<NUM>) the correction value based on the toe shape is not used for adjustment for the fit of the heel. Therefore, the adjustment may be doubly performed such as (<NUM>) + (<NUM>) or (<NUM>) + (<NUM>).

The width types of lasts are provided by classifying the shoe size in a foot width direction into types, which are a first type, a second type, a third type, and a fourth type in the second embodiment. The first type is "Narrow", which is a type with a narrower foot width than Standard. The second type is "Standard" with a standard foot width. The third type is "Wide", which is a type with a wider foot width than Standard. The fourth type is "ExtraWide", which is a type with a wider foot width than Wide.

The correction value C1 is set based on different criteria depending on which of the first to fourth types the width type of the last is. Also, as described above, a different value is set as the correction value C1 depending on the heel width ratio, short heel girth ratio, and toe shape. When the heel width ratio is a predetermined heel width reference value RW or greater, one of correction values CW1 to CW3, which are variable values that increase in proportion to the heel width ratio, may be set. More specifically, as the correction value C1, the correction value CW1 may be set when the width type is the first type, the correction value CW2 may be set when the width type is the second or third type, and the correction value CW3 may be set when the width type is the fourth type. When the short heel girth ratio is a predetermined short heel girth reference value RG or greater and when the width type is one of the second to fourth types, a correction value CG, which is a fixed value, may be set as the correction value C1. However, when the heel width ratio is the heel width reference value RW or greater and when the short heel girth ratio is the short heel girth reference value RG or greater, the greater value of the correction values CW1 to CW3 and the correction value CG may be set as the correction value C1. Furthermore, when the width type of the last is one of the second to fourth types and when the toe shape in the foot shape is the square type, a correction value CT is added to the correction value C1.

<FIG> shows the relationship between the heel width ratio and the correction value for each width type in the second embodiment. In the three lines drawn in the graph of <FIG>, from the bottom, a first line <NUM> indicates the first type as the width type, a second line <NUM> indicates the second or third type as the width type, and a third line <NUM> indicates the fourth type as the width type.

The first line <NUM> indicates the case where the width type of a last as an evaluation target is the first type, i.e., narrower than Standard, and, when the heel width ratio of the foot shape is the predetermined heel width reference value RW or greater, the correction value CW1 is set as the correction value C1. The correction value CW1 is a value that increases in proportion to the heel width ratio, in the range from a first correction value <NUM> to a second correction value <NUM>. When the heel width ratio of the foot shape is less than the predetermined heel width reference value RW, adjustment with the correction value C1 is not performed, or the correction value C1 is set to <NUM>.

The second line <NUM> indicates the case where the width type of a last as an evaluation target is the second or third type, i.e., Standard or Wide, and, when the heel width ratio of the foot shape is the predetermined heel width reference value RW or greater, the correction value CW2 is set as the correction value C1. The correction value CW2 is a value that increases in proportion to the heel width ratio, in the range from a third correction value <NUM> to a fourth correction value <NUM>. The increase rate of the correction value CW2 proportional to the heel width ratio in the second line <NUM> is smaller than the increase rates of the correction values CW1 and CW3 proportional to the heel width ratio in the first line <NUM> and the third line <NUM>.

The third line <NUM> indicates the case where the width type of a last as an evaluation target is the fourth type, i.e., Extra Wide or wider, and, when the heel width ratio of the foot shape is the predetermined heel width reference value RW or greater, the correction value CW3 is set as the correction value C1. The correction value CW3 is a value that increases in proportion to the heel width ratio, in the range from the third correction value <NUM> to a fifth correction value <NUM>.

The second correction value <NUM>, which is the upper limit value of the correction value in the first line <NUM>, and the third correction value <NUM>, which is the lower limit value of the correction value in the second line <NUM> and the third line <NUM>, may be the same value, which may be a value corresponding to a difference of one size in the shoe size.

Also, although the correction values CW1 to CW3 based on the heel width ratio are variable values, the correction value CG based on the short heel girth ratio may be a fixed value. The value of the correction value CG based on the short heel girth ratio may be a value corresponding to a difference of one size in the shoe size. The value of the correction value CG based on the short heel girth ratio may also be the same value as the second correction value <NUM>, which is the upper limit value of the correction value CW1 in the first line <NUM>. The value of the correction value CG based on the short heel girth ratio may also be the same value as the third correction value <NUM>, which is the lower limit value of the correction values CW2 and CW3 in the second line <NUM> and third line <NUM>.

<FIG> is a flowchart that shows an algorithm for calculating the correction value C1. When the width type of a last as an evaluation target is not equal to or wider than Standard, i.e., when it is the first type narrower than Standard, the process proceeds to S71 (N at S70). At S71, when the heel width ratio of the foot shape is the heel width reference value RW or greater (Y at S71), the correction value CW1 as a variable value based on the heel width ratio, in the range from the first correction value <NUM> to the second correction value <NUM>, is set as the correction value C1 (S72), and the calculation flow is terminated. When the heel width ratio is not equal to or greater than the heel width reference value RW (N at S71), the process of S72 is skipped, and the calculation flow is terminated with the correction value C1 remaining at <NUM>.

When the width type of a last as an evaluation target is Standard or wider (Y at S70) and narrower than Extra Wide (N at S73), i.e., when it is the second or third type, the process proceeds to S74. At S74, when the heel width ratio of the foot shape is the heel width reference value RW or greater (Y at S74), the correction value CW2 as a variable value based on the heel width ratio, in the range from the third correction value <NUM> to the fourth correction value <NUM>, is set as the correction value C1 (S77), and the process proceeds to S90. When the heel width ratio of the foot shape is not equal to or greater than the heel width reference value RW (N at S74) and when the short heel girth ratio of the foot shape is the short heel girth reference value RG or greater (Y at S75), the correction value CG as a fixed value based on the short heel girth ratio is set as the correction value C1 (S76), and the process proceeds to S90. When the short heel girth ratio of the foot shape is not equal to or greater than the short heel girth reference value RG (N at S75), the process of S76 is skipped, and the process proceeds to S90. When the heel width ratio of the foot shape is the heel width reference value RW or greater (Y at S74), since the correction value CG based on the short heel girth ratio is not greater than the correction value CW2, the processes of S75 and S76 are skipped.

When the width type of a last as an evaluation target is Standard or wider (Y at S70) and when it is ExtraWide or wider (Y at S73), i.e., when it is the fourth type, the process proceeds to S80. At S80, when the heel width ratio of the foot shape is the heel width reference value RW or greater (Y at S80), the correction value CW3 as a variable value based on the heel width ratio, in the range from the third correction value <NUM> to the fifth correction value <NUM>, is set as the correction value C1 (S83), and the process proceeds to S90. When the heel width ratio of the foot shape is not equal to or greater than the heel width reference value RW (N at S80) and when the short heel girth ratio of the foot shape is the short heel girth reference value RG or greater (Y at S81), the correction value CG as a fixed value based on the short heel girth ratio is set as the correction value C1 (S82), and the process proceeds to S90. When the short heel girth ratio of the foot shape is not equal to or greater than the short heel girth reference value RG (N at S81), the process of S82 is skipped, and the process proceeds to S90. When the heel width ratio of the foot shape is the heel width reference value RW or greater (Y at S80), since the correction value CG based on the short heel girth ratio is not greater than the correction value CW3, the processes of S81 and S82 are skipped.

At S90, i.e., after the correction value is calculated when the width type of the last is Standard or wider, when the toe shape is the square type (Y at S90), the correction value CT as a fixed value is added to the correction value C1 (S91), and the calculation flow is terminated. When the toe shape is not the square type (N at S90), the process of S91 is skipped, and the calculation flow is terminated.

The width score is a value calculated based on the measurement results of the ball girth and instep girth and is given by the following equation.

The "ball girth measurement value" in the above width score calculation equation is set based on predetermined criteria depending on a ball girth ratio or a instep girth ratio. The "ball girth ratio" is a ratio of the ball girth to the foot length, i.e., ball girth ratio = ball girth / foot length. The "instep girth ratio" is a ratio of the instep girth to the foot length, i.e., instep girth ratio = instep girth / foot length. When the difference between the ball girth and the instep girth is within a predetermined range, the width score is calculated using the above calculation equation. When the instep girth is greater than the ball girth by more than a criterion, the width score is calculated using the instep girth instead of the ball girth. When the ball girth is greater than the instep girth by more than a criterion, the width score is calculated using an average of the ball girth and the instep girth. In the following, a more specific calculation equation will be described.

When the ball girth is greater than the instep girth and when the difference between the ball girth ratio and the instep girth ratio is within a predetermined reference range, such as smaller than or equal to a predetermined reference value RD1 and larger than or equal to a predetermined reference value RD2, where RD2 is a negative value, the following equation is used as with the width score calculation equation described above.

Meanwhile, when the instep girth is greater than the ball girth and when the "ball girth ratio - the instep girth ratio" is smaller than the predetermined reference range, i.e., smaller than the predetermined reference value RD2, where RD2 is a negative value, since the instep girth is greater than the ball girth by more than a criterion, the instep girth measurement value is used to calculate the width score. In this case, the width score calculation equation is given by the following equation.

Thus, for a person who has the instep girth larger than the ball girth, the width score is evaluated based on the instep girth, so that the last matching rate can be calculated more accurately.

When the ball girth is greater than the instep girth and when the difference between the ball girth ratio and the instep girth ratio is larger than the predetermined reference range, i.e., larger than the predetermined reference value RD1, an average value of the ball girth measurement value and the instep girth measurement value is used to calculate the width score. In this case, the width score calculation equation is given by the following equation.

In a last, the ball girth and the instep girth are almost proportional and there is almost no difference between them. Therefore, whether to use the ball girth or the instep girth as a girth length causes no significant difference. This is because lasts are designed so that the ball girth and the instep girth are proportional. On the other hand, the actual relationship between the ball girth and the instep girth acquired from multiple measurement subjects varies greatly among them, with some people having larger ball girth and others having larger instep girth. The difference also varies from person to person. In order to calculate the width score more appropriately considering such individual differences, the value used as the ball girth measurement value is determined based on the difference between the ball girth and the instep girth.

Claim 1:
A shoe fit evaluation device (<NUM>), comprising:
a measurement value acquirer (<NUM>) that acquires measurement values of a plurality of foot part dimensions, which are dimensions of a plurality of foot parts including at least a foot length, as foot shape dimension information that defines a foot shape of a measurement subject;
a last storage (<NUM>) that stores, for each of a plurality of types of lasts, a plurality of last part dimensions, which are dimensions of last parts corresponding to a plurality of foot parts including at least the foot length, as last dimension information that defines a last;
a dimensional difference calculator (<NUM>) that calculates a part dimensional difference, which is a difference between a measurement value of a foot part dimension and a last part dimension corresponding to the foot part, by performing a predetermined adjustment for the part;
an evaluation processor (<NUM>) that calculates a last matching rate based on the part dimensional difference; and
an outputter (<NUM>) that outputs information regarding the last matching rate, wherein
the plurality of foot parts are a combination of at least one of a ball girth, a heel width, a instep girth, or a short heel girth and the foot length, characterized in that
the dimensional difference calculator (<NUM>) calculates the part dimensional difference by performing, as the predetermined adjustment, addition of a correction value based on a short heel girth ratio with respect to the foot length when the ball girth is a predetermined criterion or greater.