Print control device, printer, print control method, and program

Abstract

To form an undercoat on a nail with an ink amount without excess or deficiency.SOLUTION: A control device 10 for a printer 1 being a print control device includes a control unit 11 that functions as: acquisition means which acquires an image of a nail T (a nail image being an image of a finger U including the nail T); extraction means which extracts a region of the nail T as a nail region on the basis of the image of the nail T (nail image); and setting means which sets a discharge amount per unit area of ink for undercoat to be discharged to the nail T on the basis of a value of brightness (brightness value L) of the pixels within the range as the nail area in the image of the nail T.SELECTED DRAWING: Figure 7

Description

[Technical field]

[0001] The present invention relates to a print control device, a printing device, a print control method, and a program. [Background technology]

[0002] 2. Description of the Related Art Conventionally, printing devices (nail printing devices) that print nail designs on nails or the like are known. The color of bare nails varies from person to person, and when a design is printed on top of that, the resulting color may be different from what was imagined. For this reason, when printing on nails, it is preferable to form a base on the nail using a base ink such as white before printing the design in color.

[0003] For example, Patent Document 1 describes the application of a base coat to nails by a printing mechanism (referred to as an "ink mechanism" in Patent Document 1). If the color of the natural nail can be hidden by applying a base coat, the desired design can be printed regardless of the color of the natural nail, improving the finished quality. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2017-018589 A Summary of the Invention [Problem to be solved by the invention]

[0005] For example, when the user applies the base ink (liquid) manually, the user can form the base with an appropriate density while checking how the base color is hidden. However, there is a demand to apply (print) the base ink with a printing device in order to save the user time.

[0006] However, when the base is formed by automatically applying (printing) base ink using a printing device, if the print density is too light, the color of the base nail will not be sufficiently hidden. On the other hand, if too much base ink is applied, the ink will be wasted and it will take a long time for the applied base ink to dry, lengthening the treatment time.

[0007] The present invention has been made in consideration of the above-mentioned circumstances, and has the advantage of providing a printing control device, printing device, printing control method, and program that can form a base on a nail with just the right amount of ink. [Means for solving the problem]

[0008] In order to solve the above problem, one aspect of the print control device according to the present invention is to An acquisition means for acquiring an image of a nail; an extraction means for extracting a range of the nail as a nail region based on the image of the nail; a setting means for setting an amount of base ink per unit area to be discharged onto the nail based on a luminance value of pixels within a range defined as the nail region of the image of the nail; The present invention is characterized by comprising:

[0009] The printing device according to the present invention comprises: A print control device according to any one of claims 1 to 8, a printing means for printing by ejecting the base ink onto the nail based on the ejection amount set by the setting means; The present invention is characterized by comprising:

[0010] The printing control method according to the present invention comprises: An acquisition step of acquiring an image of a nail; an extraction step of extracting a range of the nail as a nail region based on the image of the nail; a setting step of setting an ejection amount per unit area of ​​base ink to be ejected onto the nail based on the brightness values ​​of pixels within a range defined as the nail region of the image of the nail; The present invention is characterized in that it includes:

[0011] The program according to the present invention comprises: On the computer, an image acquisition function for acquiring an image of a nail; an extraction function for extracting a range of the nail as a nail region based on the image of the nail; a setting function for setting an amount of base ink per unit area to be discharged onto the nail based on the brightness values ​​of pixels within a range defined as the nail region of the image of the nail; The present invention is characterized by realizing the above. Effect of the Invention

[0012] According to the present invention, an effect is achieved in that a base can be formed on a nail with just the right amount of ink. [Brief description of the drawings]

[0013] [Figure 1] FIG. 1 is a perspective view showing an external configuration of a main part of a printing device according to an embodiment. [Diagram 2] FIG. 2 is a block diagram showing a main control configuration of the printing apparatus according to the embodiment. [Diagram 3] 2 is a plan view showing a state in which a finger is placed on a finger placement section of the printing device. FIG. [Figure 4] 11 is a table showing an example of a discharge amount table that defines the correspondence between the brightness value of the nail area and the density level of the undercoat ink. [Diagram 5] FIG. 11 is a plan view showing an example of a nail having a low brightness value. [Figure 6] FIG. 11 is a plan view showing an example of a nail having a high brightness value. [Figure 7] 11 is a flowchart showing a process for printing a nail design by applying base ink. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] An embodiment of a print control device, a printing device, a print control method, and a program according to the present invention will be described with reference to FIGS. In addition, the embodiments described below are subject to various limitations that are technically preferable for implementing the present invention, but the scope of the present invention is not limited to the following embodiments and illustrated examples. In addition, in the following embodiment, a printing device is described as an example in which the printing device prints on the printing target of a fingernail, however, the printing target of the printing device in this invention is not limited to fingernails, and the printing target may be, for example, the nails of toes.

[0015] Fig. 1 is a perspective view showing the external configuration of the main part of a printing device according to the present embodiment, and Fig. 2 is a block diagram showing the main control configuration of the printing device. In the following embodiments, up / down, left / right, and front / rear refer to the directions shown in Fig. 1. Also, the X direction and the Y direction refer to the directions shown in Fig. 1.

[0016] As shown in FIG. 1, the printing device 1 has a housing 2 formed in a substantially box shape. The housing 2 has an opening 21 formed over almost the entire surface in the left-right direction (the lateral direction of the printing device 1, the left-right direction in FIG. 1, the X direction) in the lower part on the front side (the front side of the printing device 1, the front side in FIG. 1). Also, a notch 22 is formed in the approximate center in the left-right direction of the housing 2, continuing to the upper side of the opening 21. The notch 22 functions as an entrance and exit when the print head 41, which will be described later, is attached to and detached from the device.

[0017] In addition, for example, an operation unit 14 and a display unit 15 are provided on the top surface (top plate) of the housing 2. The shapes and arrangements of the various parts of the housing 2 are not limited to those shown in the drawings and can be set as appropriate. For example, the operation unit 14 and the display unit 15 may be provided on the side or back surface of the housing 2 rather than on the top surface. In addition, the housing 2 may be provided with two or more various operation buttons as the operation unit 14, and may be provided with various display units, indicators, etc.

[0018] The operation unit 14 is, for example, an operation button (power switch button) for turning on / off the power of the printing device 1. When the operation unit 14 is operated, an operation signal is output to the control device 10, and the control device 10 performs control according to the operation signal to operate each part of the printing device 1.

[0019] The display unit 15 is configured with, for example, a liquid crystal display (LCD), an organic electroluminescence display, or another flat display. As described above, a touch panel for performing various inputs may be integrally configured on the surface of the display unit 15. In this case, the touch panel also functions as the operation unit . The display unit 15 is connected to a control unit 11 of the control device 10, which will be described later, and is controlled by the control unit 11.

[0020] The display unit 15 is a display means for displaying various screens. For example, the display unit 15 can display a nail design input / selected by the user via the operation unit 14, various guidance screens, warning display screens, etc. In this embodiment, the display unit 15 may appropriately display the range of the nail T (a nail region, described later, see Figs. 5 and 6) extracted from the nail image captured by the imaging unit 50 (camera 51 of the imaging unit 50) of the printing device 1. Also, a print image of the design printed on the nail T may be displayed as a preview image on the display unit 15.

[0021] Inside the housing 2, a device main body 20 is housed. The device body 20 is provided with, for example, a finger placement unit 3, a printing mechanism 40, an imaging unit 50, and the like. As shown in FIG. 1, the finger placement section 3 is disposed at approximately the center in the left-right direction (X direction) on the front side of the device body 20, and holds a finger U having a nail T (see FIG. 3, etc.), which is the printing target in this embodiment, within an area suitable for printing. The finger placement section 3 has an opening 31 on the front side of the device. A finger placement member 32 is provided inside the finger placement section 3. The finger placement member 32 supports the finger U inserted from the opening 31 by pushing it up from below, and is made of, for example, a flexible resin. A window 33 is formed on the upper surface of the finger placement section 3 to expose a nail T portion of a finger U inserted through the opening 31 and held by the finger placement member 32. At the rear part (the rear side of the device, the back side) within finger placement section 3, there is provided a nail locking part 35 (see FIG. 3) against which the tip of finger U abuts and to which the center of the tip of the nail T is hooked.

[0022] The printing mechanism 40 is a printing means that performs printing on the surface of the nail T, which is a printing target, according to printing data generated in a control unit 11 (see FIG. 2) described later. The printing mechanism 40 includes a head that performs the printing operation (hereinafter referred to as the "printing head 41"), a carriage 42 on which the printing head 41 is mounted and held, and a head moving mechanism 49 (see Figure 3) for moving the carriage 42 carrying the printing head 41.

[0023] As shown in Fig. 1, the carriage 42 of this embodiment is equipped with a base head 41a and a design head 41b as the print head 41. In the following, when simply referring to the "print head 41", this includes both the base head 41a and the design head 41b. Note that the arrangement of the base head 41a and the design head 41b is not limited to the illustrated example. For example, a plurality of carriages may be provided, and each print head 41 may be mounted on a different carriage.

[0024] The base head 41a is a head for printing things other than the design, and applies (prints) a liquid agent (hereinafter referred to as "base ink") that forms a base in the area where the design is to be printed, in an area recognized as a nail area extracted based on a nail image described later, before printing the design. The base ink applied (printed) by the base head 41a is preferably a liquid agent that is white or a color close to white, so that the ink will have good color development when the design is printed.

[0025] Depending on the color of the nail T (bare nail with nothing applied) to be printed, applying the base ink once to the entire nail area may not be enough to conceal the color of the bare nail, and it may be necessary to apply the base ink multiple times to increase the amount of ink applied onto the nail T. For this reason, in this embodiment, the control unit 11, which will be described later, sets the discharge amount of the base ink according to the brightness information of the nail T (in the embodiment, the "brightness value L").

[0026] The design head 41b prints a design on the nail area after the base is formed. The design head 41b can eject ink of each color (hereinafter referred to as "color ink"), such as cyan (C; CYAN), magenta (M; MAGENTA), and yellow (Y; YELLOW). Note that the types of color ink that the design head 41b can eject are not limited to these, and it may be possible to eject ink of other colors.

[0027] In this embodiment, the base head 41a and the design head 41b are both inkjet heads of an inkjet type that print by forming the ink into fine droplets and spraying the ink from the inkjet surface directly onto the nail surface, which is the surface to be printed on the print target (nail T). The configuration of the print head 41 is not particularly limited, but for example, it is a cartridge-integrated head in which an ejection mechanism such as an ink ejection surface and an ink cartridge (neither of which is shown) that stores ink inside are integrated.

[0028] The head movement mechanism 49 includes an X-direction movement mechanism equipped with an X-direction movement motor 46 for moving the print head 41 (the carriage 42 carrying the print head 41) in the left-right direction of the device (X direction), and a Y-direction movement mechanism equipped with a Y-direction movement motor 48 for moving the print head 41 (the carriage 42 carrying the print head 41) in the front-rear direction of the device (Y direction). The head movement mechanism 49 drives the X-direction movement motor 46 to move the print head 41 in the left-right direction of the device (X direction), and drives the Y-direction movement motor 48 to move the print head 41 in the front-rear direction of the device (Y direction). The operations of the X-direction movement motor 46, Y-direction movement motor 48 and print head 41 (the ejection mechanism of the print head 41) of the head movement mechanism 49 are controlled by a control unit 11 (see FIG. 2) of the control device 10 described below.

[0029] Additionally, on the inside of the top surface (top plate) of the housing 2, at a position above the window portion 33 of the finger placement section 3, an imaging section 50 is provided which captures an image of the nail T (a finger U including the nail T) exposed through the window portion 33 to obtain an image of the nail T (an image of the finger U including the nail T, hereinafter also referred to as a "nail image"). The imaging unit 50 only needs to be provided in a position where it can capture an image of the nail T of the finger U placed on the finger placement unit 3, and the specific location of the imaging unit 50 is not particularly limited. For example, the imaging unit 50 may be configured to be movable in the X and Y directions by a head moving mechanism 49 that moves the print head 41, or the like.

[0030] The imaging unit 50 includes, for example, a camera 51 and a light source 52 that illuminates the nail T, which is the subject of imaging. The camera 51 includes, for example, a solid-state imaging element such as a CCD (Charge Coupled Device) type or a CMOS (Complementary Metal Oxide Semiconductor) type having a predetermined number of pixels, a lens, and the like. The light source 52 is, for example, an illumination unit including a plurality of white LEDs. Note that the light source 52 is not limited to an LED as long as it can illuminate the subject of imaging by the camera 51. The nail image captured by the imaging unit 50 (camera 51 of the imaging unit 50) is sent to the control unit 11 described below and acquired by the control unit 11. The nail image may be stored in the storage unit 12 described below.

[0031] The printing device 1 also includes a communication unit 13 that communicates with an external device (not shown). The external device is, for example, a terminal device such as a smartphone. The communication unit 13 includes a wireless communication module and a wired communication module that enable communication between external devices, and communicates with appropriate external devices. The communication between the printing device 1 and the external device may use a network line such as the Internet, or may be wireless communication based on a short-range wireless communication standard such as Bluetooth (registered trademark) or Wi-Fi. When communication is performed via a network, the network used for communication may use any line. Furthermore, communication between the printing device 1 and the terminal device is not limited to wireless communication, and may be configured to enable transmission and reception of various data between the two devices via a wired connection. The communication unit 13 may be any unit capable of communicating with the terminal device, and a unit conforming to the communication standard of the communication unit of the terminal device is applied.

[0032] The control device 10 is mounted on a board (not shown) or the like that is disposed in the housing 2, the device main body 20, or the like. As shown in FIG. 2, the control device 10 is a computer including a control unit 11 consisting of a processor such as a CPU (Central Processing Unit), and a memory unit 12 consisting of a ROM (Read Only Memory), a RAM (Random Access Memory), etc. (neither of which are shown). The storage unit 12 may be configured separately and provided outside the control device 10.

[0033] The storage unit 12 has a program storage area 121 in which various programs for operating the printing device 1 are stored. Specifically, the memory unit 12 stores various programs such as a printing program for performing printing processing, a nail area extraction program for extracting the area of ​​the nail T from the nail image, and a luminance information detection program for detecting luminance information (specifically, the luminance value L) of the nail T from the nail image, and the control unit 11 loads these programs, for example, in a working area of ​​a RAM, and the programs are executed in the control unit 11, thereby providing overall control of each part of the printing device 1. Each function of the control unit 11 is realized by cooperation between the control unit 11 and the programs stored in the program memory area 121 of the memory unit 12.

[0034] In this embodiment, the control device 10 is a "print control device" and its control unit 11 has the following functions in particular. First, the control unit 11 functions as an acquisition unit that acquires an image of the nail T (a nail image that is an image of a finger U including the nail T). Here, the "nail image" is an image of a bare nail with nothing applied thereto. For example, the control unit 11 controls the operation of the imaging unit 50 to capture an image of the finger U placed on the finger placement unit 3 with the camera 51, and acquires a nail image from the imaging unit 50. Note that the nail image is not limited to one acquired by the imaging unit 50 of the printing device 1. For example, in the case where a terminal device such as a smartphone is linked to the printing device 1 via the communication unit 13, the control unit 11 may acquire a nail image captured by such an external terminal device or the like via the communication unit 13.

[0035] Furthermore, when the control unit 11 acquires an image of the nail T, it functions as an extraction means for extracting the range of the nail T as a nail region (natural nail region) based on the image of the nail T. The method by which the control unit 11 extracts the nail region from the nail image is not particularly limited. For example, the control unit 11 performs various image analyses on the nail image to detect the brightness difference between the nail T and other parts (such as the skin of the finger U) and detects the boundary as a contour shape. Then, the area inside the contour is extracted (recognized) as the nail region.

[0036] Furthermore, when the control unit 11 extracts the nail region from the image of the nail T, it acquires the luminance values ​​(luminance value L) of the pixels within the range determined as the nail region. Then, the control unit 11 also functions as a specifying unit that specifies the pixel with the lowest luminance (luminance value L) among all the pixels within the range determined as the nail region. Specifically, the control unit 11 functions as a conversion means that acquires the RGB values ​​of each of all pixels of the image of the nail T and converts them into the HSL color space. Then, as a specification means, the control unit 11 specifies the pixel with the lowest luminance (luminance value L) among all pixels of the image of the nail T based on the HSL color space of each of all pixels.

[0037] The method of identifying the pixel with the lowest luminance (luminance value L) among all pixels of the image of the nail T is not limited to the example given here, and other methods may be used. For example, it is not essential for the control unit 11 to convert the RGB values ​​of all pixels of the image of the nail T into the HSL color space. The control unit 11 may identify the pixel with the lowest luminance (darkest) among all pixels within the range determined to be the nail region without converting to the HSL color space.

[0038] Then, the control unit 11, as a determination means, identifies the pixel with the lowest brightness among all the pixels of the image of the nail T, and further, as a setting means, sets the ejection amount per unit area of ​​the base ink to be ejected onto the nail T based on the brightness value (brightness value L) of the identified pixel. When setting the ejection amount of the base ink, for example, the control unit 11 refers to an ejection amount table that associates the minimum value of the luminance value L identified from the nail image with the ejection amount of the base ink.

[0039] FIG. 4 is a table showing an example of the discharge amount table. The discharge amount table is stored in advance in, for example, the storage unit 12. In other words, the storage unit 12 is a storage means for storing in advance a discharge amount table in which the brightness value and the discharge amount of the undercoat ink are associated with each other. Note that the storage means for storing the discharge amount table is not limited to being stored in the storage unit 12 of the printing device 1, and may be an external storage means accessible by the control unit 11.

[0040] For example, FIG. 5 is an example of a nail T with a relatively low luminance value L (eg, "luminance value L0-24" in FIG. 4), and FIG. 6 is an example of a nail T with a relatively high luminance value L (eg, "luminance value L75-100" in FIG. 4). When the brightness value L is low, as in the case of nail T shown in FIG. 5, the color of the natural nail cannot be concealed unless the density level of the base ink is increased. In contrast, when the brightness value L is high, as in the case of nail T shown in FIG. 6, the color of the natural nail can be concealed without applying the base ink very thickly. For this reason, in the example shown in FIG. 4, the density level of the base ink required to conceal the color of the natural nail, "100", is associated with the case of "brightness value L0 to 24". Also, the density level of the base ink required to conceal the color of the natural nail, "25", is associated with the case of "brightness value L75 to 100".

[0041] Here, the density of the base ink itself is constant for each ink (ink type, composition, etc.), and the density of the ink itself in the base head 41a cannot be manipulated. Therefore, when it is desired to increase the density level of the base ink, the control unit 11 improves the apparent degree of concealment by depositing the ink multiple times. In other words, "increasing the density level" means "increasing the amount of ink ejected." For this reason, in the ejection amount table, a higher brightness value corresponds to a smaller ejection amount, and a lower brightness value corresponds to a larger ejection amount (per unit area) of the undercoat ink.

[0042] In the ejection amount table shown in FIG. 4, the concentration level of the base ink "100" means the maximum value, or limit value, of the base ink that can be ejected into the nail area, taking into consideration the type, composition, etc. of the base ink (ink stored in the base head 41a) used for printing, the ejection performance of the base head 41a of the printing device 1 used for printing, and the type of ink receiving layer, if an ink receiving layer is formed to receive the ink ejected onto the nail before printing the base ink.

[0043] That is, for example, if the type of ink and the performance of the base head 41a allow for about three overlapping deposits in the same nail area, the density level of the base ink "100" refers to the amount of ink ejected when the ink is ejected three times. Also, if the type of ink and the performance of the base head 41a allow for about four overlapping deposits in the same nail area, the density level of the base ink "100" refers to the amount of ink ejected when the ink is ejected four times. And, when this limit value is "100," the case where the ejection amount should be about half of that is set to "50," and the case where the ejection amount should be about one-quarter of that is set to "25," etc.

[0044] In the example shown in FIG. 4, the ink ejection amount is specified in four stages, from the brightness value L of "0 to 24" which is the density level "100" required for concealment, to the brightness value L of "75 to 100" which is the density level "25" required for concealment, but the correspondence between the brightness value and the ejection amount of the base ink is not limited to four stages. The correspondence may be less than the illustrated example, such as two or three stages, or may be divided into more stages. Also, the brightness value L may be linearly and steplessly associated with the density level of the antimagnetic ink required for concealment.

[0045] In addition, the control unit 11 may obtain various nail information such as the curved shape of the nail T and the height of the nail T (the vertical position of the nail T) from the nail image, etc., and make appropriate corrections by referring to this data when generating the printing data. The control unit 11 also controls the operation of each unit of the device, such as the printing mechanism 40, the imaging unit 50, the communication unit 13, the display unit 15, etc., as appropriate.

[0046] [Effect] Next, with reference to FIG. 7, the operation of the print control device (control device 10) of this embodiment and the printing device 1 including the same, and print control processing will be described. FIG. 7 is a flowchart showing the print control process in this embodiment.

[0047] When applying nail printing to a nail using the printing device 1, a message or the like is displayed first urging the user to place a finger U corresponding to the nail T to be printed on the finger placement section 3 of the printing device 1 (step S1). When the user follows this and places the finger U on the finger placement section 3, the control section 11 operates the camera 51 of the imaging section 50 to capture an image of the finger U including the nail T exposed through the window section 33 of the finger placement section 3, and obtains the image (a natural nail image) (step S2).

[0048] When the nail image is acquired, the control unit 11 performs image processing and the like on the natural nail image and extracts the nail region from the image (recognizing the natural nail region, step S3). The control unit 11 also detects brightness information (brightness value L) within the area extracted as the nail area from the natural nail image (step S4), and sets the discharge amount (per unit area) of the base ink based on the detected brightness information (brightness value L) (step S5).

[0049] Specifically, the control unit 11 obtains the RGB values ​​of each pixel in the range determined as the nail region among all pixels of the nail image, and converts them into the HSL color space. Then, based on the HSL color space of each pixel, the control unit 11 identifies the pixel with the lowest brightness (brightness value L) among all pixels in the range determined as the nail region, and sets this pixel as the minimum brightness value L in the nail region.

[0050] When the minimum value of the brightness value L within the nail area is derived, the control unit 11 refers to the discharge amount table (see FIG. 4) to determine the “concentration level of the base ink required for concealment” that corresponds to the derived minimum value of the brightness value L, and sets the ink discharge amount that should be used for that concentration level in light of the performance of the printing device 1 and the base head 41a, and the properties and composition of the base ink stored in the base head 41a. That is, in light of the information and conditions such as the performance of the printing device 1 and the base head 41a, and the properties and composition of the base ink stored in the base head 41a, if three overlapping strokes is the maximum or limit value of the ink ejection amount that can be ejected by the printing device 1, the control unit 11 sets the ink ejection amount for three overlapping strokes as a density level of "100" and finds the ink ejection amount that corresponds to the density level corresponding to the minimum value of the luminance value L. Then, the control unit 11 sets the ink ejection amount corresponding to that density level as the "ejection amount of base ink required for concealment."

[0051] Furthermore, the control unit 11 generates base printing data for printing on the extracted nail area with a set ejection amount of base ink (step S6), and controls the base head 41a of the printing mechanism 40, etc. to print the base with the base ink based on the generated base printing data (step S7). Then, when the base is formed by the base ink, the control unit 11 further controls the printing mechanism to print the nail design on the base with the design ink (color ink) by the design head 41b (step S8). As a result, the nail design is printed on the nail T.

[0052] Although detailed explanation is omitted here, after the base is formed with the base ink, drying and other processes are required, so the control unit 11 causes the display unit 15 or the like to display a message urging the user to remove the finger U from the device, perform necessary processes such as drying, and then place the finger on the finger placement unit 3 again. Then, when the finger U is repositioned for design printing, the control unit 11 again photographs the finger U with the camera 50 of the imaging unit 50 to obtain a nail image, recognizes the nail area which is the range in which the design should be printed, and confirms the range to be printed, etc. before causing the design to be printed.

[0053] This allows the design to be printed on top of the base ink, which is sufficiently covered by white or other color, allowing nail printing to be done exactly as imagined, regardless of the natural nail color.

[0054] [effect] As described above, according to this embodiment, the printing control device (control device 10) of the printing device 1 acquires an image of the nail T, extracts a range of the nail T as a nail area based on the image of the nail T, and is equipped with a control unit 11 that sets the ejection amount (per unit area) of the base ink to be ejected onto the nail T based on the brightness value (brightness value L) of the pixels within the range of the image of the nail T that has been determined to be the nail area. This allows the amount of ink to be set as the amount of base ink that is just enough to conceal the color of the base nail. Therefore, by printing according to this setting, a uniform base of white or the like can be formed regardless of the color of the base nail where nothing is applied, and a design can be printed on the base with a good finish. Furthermore, since the base can be formed with an appropriate ejection amount required to conceal the natural nail color, it is possible to avoid ejecting too much ink unnecessarily and also to prevent the ink from taking too long to dry.

[0055] Furthermore, in this embodiment, the control unit 11 identifies the pixel with the lowest brightness among all pixels within the range defined as the nail area in the image of the nail T, and sets the amount of base ink to be ejected onto the nail T based on the brightness value (brightness value L) of the identified pixel. This effectively prevents the occurrence of a portion of the nail T where the natural nail color cannot be completely concealed.

[0056] In this embodiment, the control unit 11 also functions as a conversion means for converting the RGB values ​​of each of the pixels of the image of the nail T into HSL color space, and identifies the pixel with the lowest brightness among all the pixels of the image of the nail based on the HSL color space of each of the pixels. Therefore, the pixel with the lowest luminance (luminance value L) can be more appropriately identified by objective evaluation based on luminance, hue, and saturation.

[0057] Furthermore, in this embodiment, a discharge amount table in which the brightness value (brightness value L) corresponds to the discharge amount of the base ink is stored in advance in the memory unit 12 or the like, and the control unit 11 sets the discharge amount of the base ink to be discharged onto the nail T based on this discharge amount table. Therefore, there is no need to use a complicated conversion formula or the like, and the ejection amount of the undercoat ink to be set can be obtained easily and in a short time.

[0058] In this embodiment, in the discharge amount table, the higher the brightness value (brightness value L), the smaller the discharge amount is associated. Nails T with a high brightness value (brightness value L) are relatively whitish to begin with, and so there is little need to apply undercoat ink. In such cases, reducing the amount of ink ejected can reduce ink waste and shorten the time it takes for the undercoat ink to dry. This shortens the overall treatment time and reduces the burden on the user.

[0059] [Variations] Although the embodiment of the present invention has been described above, it goes without saying that the present invention is not limited to such an embodiment, and various modifications are possible without departing from the gist of the present invention.

[0060] For example, in this embodiment, the control unit 11 as a setting means identifies the pixel with the lowest brightness (brightness value L) among all pixels in the nail area, and sets the amount of base ink to be ejected onto the nail T based on the brightness value (brightness value L) of the identified pixel, but the method of setting the amount of base ink to be ejected is not limited to this. For example, the control unit 11 as a setting means may set the amount of base ink ejected (per unit area) onto the nail T based on the average value of the brightness values ​​(brightness value L) of pixels within the range designated as the nail area. This makes it possible to prevent a discharge amount that is too large to actually conceal the color of a nail T that has some parts with low brightness values ​​(brightness value L) but has a high overall brightness value L, from being set.

[0061] In addition, the control unit 11, which serves as a setting means, may set the amount of base ink ejected (per unit area) onto the nail T based on the median brightness value (brightness value L) of pixels within the range designated as the nail area. Even in this case, it is possible to prevent a discharge amount that is too large to actually conceal the color of a nail T that has some parts with low brightness values ​​(brightness value L) but has a high brightness value L overall.

[0062] Furthermore, in the example shown in this embodiment, when looking at the pixel brightness value L, the entire nail T was the target, but there may be cases where the brightness value L varies depending on the position, such as the nail T being relatively bright in the central part in the width direction and relatively dark at both ends. For this reason, for example, the control unit 11 as a setting means may divide the nail area into multiple unit areas and set the amount of base ink to be ejected into each unit area of ​​the nail T based on the brightness value (brightness value L) of the pixel for each unit area. In this way, it is possible to adequately conceal the entire nail T with the base ink, and also to prevent over-application of the base ink in areas with high brightness values ​​L. This allows a more appropriate ink amount to be set, and prevents ink waste.

[0063] Furthermore, the amount of base ink ejected may be set for each pixel. In this way, the amount of base ink ejected can be set more precisely, so that the amount is neither too much nor too little, and the base can be formed appropriately.

[0064] In addition, as in this embodiment, when the control unit 11 also functions as a conversion means for converting the RGB values ​​of each of all pixels of the image of the nail T into HSL color space, and the pixel with the lowest brightness among all pixels of the image of the nail is identified based on the HSL color space of each of all pixels, the ejection amount of the base ink may be set taking into consideration not only the brightness value L but also other elements such as hue and saturation. This is expected to enable more appropriate responses to be made according to the color of various nails T.

[0065] Furthermore, in this embodiment, the RGB values ​​of all pixels of the nail image are converted into the HSL color space, and the control unit 11, as a setting means, sets the amount of base ink to be ejected onto the nail T based on the luminance values ​​(luminance value L) of the pixels within the range designated as the nail area, but the method of setting the amount of base ink to be ejected is not limited to this. For example, the control unit 11 may convert the RGB values ​​of each of all pixels of the nail image into a color space other than the HSL color space (for example, the Lab color space). Then, when the RGB values ​​are converted into the Lab color space, the control unit 11, as a setting means, may set the amount of base ink to be ejected (per unit area) onto the nail T based on the brightness values ​​of the pixels within the range designated as the nail area. In this case as well, the color of the nail T can be objectively evaluated and an appropriate amount of base ink to be discharged for each nail T, neither too much nor too little, can be set.

[0066] In this case, as in the case where the brightness value L is used, the pixel with the lowest brightness value among all pixels in the nail area may be identified, and the amount of base ink to be ejected onto the nail T may be set based on the brightness value of the identified pixel, or the amount of base ink to be ejected onto the nail T (per unit area) may be set based on the average or median brightness value of all pixels in the nail area.

[0067] In addition, in this embodiment, an example has been given of the case where the control unit 11, as a setting means, sets the ejection amount of the base ink to be ejected onto the nail T based on an ejection amount table in which the brightness value (brightness value L) is associated with the ejection amount of the base ink, but the method of setting the ejection amount of the base ink is not limited to this. For example, the luminance value (luminance value L) and the discharge amount of the undercoat ink may be associated with each other by a conversion formula or the like without using a conversion table.

[0068] In addition, in this embodiment, one printing device 1 is equipped with a base head 41a and a design head 41b as the printing head 41, and when automatically applying (printing) the base ink, printing is performed using the base head 41a. However, the method of applying (printing) the base ink is not limited to this. For example, a printing device for design printing equipped with a print head for printing designs using design ink (colored ink) and a printing device dedicated to base printing equipped with a printing section (print head, pen, etc.) for printing base ink may be separately prepared, and the base ink may be applied (printed) to the nail T using the printing device dedicated to base printing to form a base, and then the finger may be held in the finger placement section of the printing device for design printing to print the design on the nail T. In this case, the control device of the printing device dedicated to base printing functions as the print control device.

[0069] In addition, in this embodiment, the printing device 1 is configured to complete the printing operation by itself, and an example is given of the case where the control device 10 of the printing device 1 is a print control device, but the print control device is not limited to the control device 10 of the printing device 1. For example, the printing device 1 may be configured to print on the nail T in cooperation with various terminal devices such as a smartphone, and in this case, a control device of the terminal device may function as a print control device.

[0070] Furthermore, in this embodiment, the printing device 1 is configured to include an inkjet type print head 41 as the print head 41, but the configuration of the print head 41 is not limited to this. The print head 41 may have a different configuration from the inkjet type print head 41, such as a syringe type head or a pen type head. In this case, it is also possible to print ink or liquid with a relatively high viscosity.

[0071] Although several embodiments of the present invention have been described above, the scope of the present invention is not limited to the above-described embodiments, but includes the scope of the invention described in the claims and its equivalents. [Explanation of symbols]

[0072] 1 Printing device 3 Finger placement area 10 Control device 11 Control section 12 Storage section 40 Printing mechanism 41 Print Head 41a Base Head 41b Design Head 50 Imaging unit 51 Camera 52 Light source T-nail U finger

Claims

1. An acquisition means for acquiring an image of a nail; an extraction means for extracting a range of the nail as a nail region based on the image of the nail; a setting means for setting an amount of base ink per unit area to be discharged onto the nail based on a luminance value of pixels within a range defined as the nail region of the image of the nail; A print control device comprising:

2. The higher the brightness value of the pixel in the range determined as the nail region, the smaller the discharge is set.

2. The print control device according to claim 1.

3. a specifying means for specifying a pixel having the lowest brightness among all pixels within the range defined as the nail region in the image of the nail, the setting means sets an amount of base ink to be discharged onto the nail based on the luminance value of the pixel identified by the identifying means.

2. The print control device according to claim 1.

4. A conversion means for converting the RGB values ​​of all pixels of the image of the nail into an HSL color space, The specifying means specifies a pixel having the lowest brightness among all pixels of the image of the nail based on the HSL color space of each of the pixels.

4. The print control device according to claim 3.

5. The ink ejection amount table is stored in advance in such a manner that the brightness value is associated with the ejection amount of the undercoat ink. the setting means sets an ejection amount of the base ink to be ejected onto the nail based on the ejection amount table.

2. The print control device according to claim 1.

6. the setting means sets an amount of base ink to be discharged onto the nail based on an average value of luminance values ​​of pixels within the range determined as the nail area.

2. The print control device according to claim 1.

7. the setting means sets an amount of base ink to be discharged onto the nail based on a median value of luminance values ​​of pixels within the range determined as the nail area.

2. The print control device according to claim 1.

8. the setting means divides the nail area into a plurality of unit areas, and sets an ejection amount of base ink to be ejected into each of the unit areas of the nail based on a luminance value of a pixel for each unit area.

2. The print control device according to claim 1.

9. A print control device according to any one of claims 1 to 8, a printing means for printing by ejecting the base ink onto the nail based on the ejection amount set by the setting means; A printing device comprising:

10. An acquisition means for acquiring an image of a nail; an extraction means for extracting a range of the nail as a nail region based on the image of the nail; a setting means for setting an amount of base ink to be discharged onto the nail based on a brightness value of pixels within a range defined as the nail region of the image of the nail; A print control device comprising:

11. An acquisition step of acquiring an image of a nail; an extraction step of extracting a range of the nail as a nail region based on the image of the nail; a setting step of setting an ejection amount per unit area of ​​base ink to be ejected onto the nail based on the brightness values ​​of pixels within a range defined as the nail region of the image of the nail; A printing control method comprising:

12. On the computer, an image acquisition function for acquiring an image of a nail; an extraction function for extracting a range of the nail as a nail region based on the image of the nail; a setting function for setting an amount of base ink per unit area to be discharged onto the nail based on the brightness values ​​of pixels within a range defined as the nail region of the image of the nail; A program for realizing the above.

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