Printing device, printing control method, and program

Abstract

To determine the state of an ink tank on the basis of the result of comparison between print data and the printed result.SOLUTION: A printing device 100 includes multiple ink tanks that hold ink, a printing unit 160 that applies ink to a printing object medium, an imaging unit 150 that images the printing object medium, and a control unit 110. The control unit 110 acquires pixel values in the print data to be printed on the printing object medium as data pixel values, controls the printing unit 160 to perform printing on the printing object medium on the basis of the print data, images the printing object medium printed by the printing unit by the imaging unit 150 to obtain imaging data, acquires pixel values in the imaging data as imaging pixel values, and determines the state of the ink tank on the basis of the comparison result between the data pixel values and the imaging pixel values.SELECTED DRAWING: Figure 1

Description

[Technical field]

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

[0002] Because printing devices consume ink and developer (toner) every time printing is performed, many of them are equipped with a function to notify the user when it is time to replace the ink tank or toner cartridge. For example, Patent Document 1 discloses a technology that notifies the user of the end of the cartridge's life based on the amount of developer remaining in the cartridge. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2003-114571 A Summary of the Invention [Problem to be solved by the invention]

[0004] The technology disclosed in Patent Document 1 notifies the user that the cartridge has reached the end of its life when the operating time counted by a counting means exceeds a predetermined threshold after the remaining amount of developer in the cartridge falls below a predetermined value. However, this conventional technology determines the life of the ink tank or cartridge solely based on the remaining amount and operating time, and is not able to determine the remaining amount based on the actual print results.

[0005] The present invention has been made in consideration of the above-mentioned situation, and aims to provide a printing device, a printing control method, and a program that can determine the status of an ink tank based on the results of comparing print data and print results. [Means for solving the problem]

[0006] In order to achieve the above object, a printing device according to the present invention comprises: A plurality of ink tanks for holding ink; A printing unit that applies the ink to a print medium; an imaging unit that images the printing medium; A control unit, The control unit is Obtaining pixel values ​​in the print data to be printed on the print medium as data pixel values; Controlling the printing unit so as to print on the print medium based on the print data; The printing medium printed by the printing unit is imaged by the imaging unit to obtain imaging data; A pixel value in the imaging data is acquired as an imaging pixel value; The state of the ink tank is determined based on a comparison result between the data pixel value and the captured pixel value. Effect of the Invention

[0007] According to the present invention, the state of the ink tank can be determined based on the result of comparing the print data with the print result. [Brief description of the drawings]

[0008] [Figure 1] 1 is a block diagram showing an example of a functional configuration of a printing device according to a first embodiment. [Diagram 2] FIG. 1 is a front view of a printing device according to a first embodiment. [Diagram 3] FIG. 1 is a top view of a printing apparatus according to a first embodiment. [Figure 4] 1 is a flowchart illustrating an example of a printing process according to the first embodiment. [Diagram 5] FIG. 11 is a diagram for explaining an example of a color conversion table. [Figure 6] 10 is a diagram for explaining an example of an imaging color conversion table; FIG. [Figure 7] 13 is a flowchart illustrating an example of a printing process according to a second embodiment. [Figure 8] 13 is a flowchart illustrating an example of a printing process according to a third embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals.

[0010] (Embodiment 1) The printing device 100 according to the first embodiment is an inkjet printer capable of printing nail designs on fingernails, nail tips, and the like.

[0011] As shown in FIG. 1, the printing device 100 includes, as its functional components, a control unit 110, a storage unit 120, a display unit 130, an operation input unit 140, an imaging unit 150, a printing unit 160, and a communication unit 170.

[0012] The control unit 110 is configured with a processor such as a CPU (Central Processing Unit), etc. The control unit 110 executes processes for realizing each function of the printing device 100 and a printing process, which will be described later, by using a program stored in the storage unit 120.

[0013] The storage unit 120 stores the programs executed by the control unit 110 and necessary data. The storage unit 120 may include, but is not limited to, a RAM (Random Access Memory), a ROM (Read Only Memory), a flash memory, etc. The storage unit 120 stores the programs executed by the control unit 110, image data of nail designs to be printed on a print medium (nails, nail tips, etc.) by the printing unit 160, a color conversion table 121 described later, an image capture color conversion table 122, etc. The storage unit 120 may be provided inside the control unit 110.

[0014] The display unit 130 includes a display such as a liquid crystal display or an organic EL (Electro-Luminescence) display, and displays the nail design to be printed, and displays operation and setting error notifications, etc. When notifying the user that the ink tank is out of ink in the printing process described below, the display unit 130 functions as a notification unit.

[0015] Operation input unit 140 is a user interface such as a push button switch, a keyboard, a touch panel, etc., and accepts operation input from a user. When operation input unit 140 includes a touch panel, it may be a touch panel integrated with the display of display unit 130. Operation input unit 140 includes, for example, a print instruction button, an OK button, a CANCEL button, etc.

[0016] The imaging unit 150 includes a camera and an LED (Light Emitting Diode), and illuminates a print medium with the LED and captures the image with the camera, thereby acquiring the captured image.

[0017] The printing unit 160 includes an ink holding unit that holds ink, a print head that prints by ejecting ink onto a print medium, and a drive unit (X-axis drive unit and Y-axis drive unit) that moves the print head. The printing unit 160 prints a nail design by applying ink to a print medium. The ink holding unit holds ink for at least three colors (cyan, magenta, and yellow), and each color of ink is held in an ink tank for that color. In other words, the ink holding unit has at least three ink tanks. Note that the ink tank here is a general term for an object that holds a substance that is applied to a print medium during printing, and for example, ink cartridges and toner cartridges are also included in the ink tank.

[0018] The communication unit 170 is an interface for the printing device 100 to communicate with other devices (such as a server). The printing device 100 can obtain image data of a nail design from a server via the communication unit 170, for example.

[0019] Next, the structure of the printing device 100 will be described with reference to FIG. 2 (front view) and FIG. 3 (top view).

[0020] 2 and 3, the print head 161 of the printing device 100 can be moved back and forth and left and right by an X-axis drive unit 162 that moves the print head 161 left and right and a Y-axis drive unit 163 that moves the print head 161 in a front and back direction. When the print medium is a nail 202, the user places the finger 201 on a finger rest 148 made of a cushioning material and fixes the nail 202, which is the print medium, by pressing it from above with a finger rest 149. The finger rest 148 and the finger rest 149 adjust the surface of the nail 202 of the finger 201 to a constant height.

[0021] The print head 161 is moved by the drive units (X-axis drive unit 162 and Y-axis drive unit 163) under the control of the control unit 110, and prints a nail design on the print medium (such as the nail 202) by ejecting ink supplied from the ink holder onto the print medium. The print head 161, X-axis drive unit 162, and Y-axis drive unit 163 are included in the printing unit 160.

[0022] As shown in FIG. 2, a camera 151 is installed on the ceiling of the printing device 100, and LEDs 152 are installed around the camera 151. These are included in the imaging unit 150. Under the control of the control unit 110, the control unit 110 obtains an image of the medium to be printed by illuminating the medium to be printed with the LEDs 152 and photographing the medium with the camera 151. Then, information on the medium to be printed (target information) is obtained by performing image recognition on the image of the medium to be printed. Examples of target information include the shape, size, and position of the nail, and the color distribution on the nail. Note that the camera 151 and LEDs 152 are omitted from FIG. 3 to prevent them from overlapping with the print head 161, X-axis drive unit 162, finger rest 148, etc., making it difficult to see.

[0023] Next, the print process of the printing device 100 will be described with reference to Fig. 4. When a user instructs the printing device 100 to print, execution of the print process begins.

[0024] First, the control unit 110 acquires print data of a nail design selected by the user (step S101). In step S101, the control unit 110 may display a list of nail designs on the display unit 130 and acquire the nail design selected by the user from the list, or may acquire via the communication unit 170 the nail design selected by the user by operating another device (such as a personal computer (PC), tablet, or smartphone).

[0025] Next, the control unit 110 prompts the user to fix the print medium (a finger, a nail chip, etc.) on the finger rest 148 (step S102). Specifically, the control unit 110 prompts the user to fix the finger on the finger rest 148 by displaying a message such as "Place your finger on the finger rest and press it with the finger pressing unit to fix it" on the display unit 130. Although this is omitted in FIG. 4 to avoid complication, after the processing of step S102, the control unit 110 determines that the finger is fixed on the finger rest 148 and then proceeds to step S103.

[0026] Regarding the determination of whether the print medium (finger, nail chip, etc.) is fixed to the finger rest 148, the control unit 110 may display a message such as "Please fix your finger on the finger rest. Once fixed, press the OK button" on the display unit 130, and determine that the print medium is fixed to the finger rest when the OK button is pressed. Also, for example, the finger rest 148 may be equipped with a sensor such as a pressure sensor, and the control unit 110 may determine that the print medium is fixed based on a detection value by the sensor. Also, this determination may be made after step S103, and the control unit 110 may determine whether the print medium is fixed to the finger rest 148 based on the image acquired in step S103, and if the print medium is not fixed, the process may return to step S102.

[0027] Then, the control unit 110 captures an image of the print medium using the imaging unit 150, and acquires image data of the print medium (step S103).

[0028] Then, the control unit 110 recognizes the printing area on the print medium based on the image data acquired in step S103, and corrects the print data of the nail design acquired in step S101 using the curvature and inclination of the print medium (step S104). The curvature and inclination of the print medium may be input by the user using a separate dedicated application software (for example, software that allows the user to easily input the curvature and inclination using a GUI (Graphical User Interface)). The method by which the control unit 110 corrects the print data of the nail design is not particularly limited. Any method may be used for correction as long as the curvature and inclination of the print area of ​​the print medium are taken into consideration and the nail design is properly fitted (mapped) to the print area of ​​the print medium.

[0029] Next, the control unit 110 converts the RGB (Red, Green, Blue) values ​​of the print data of the nail design into CMY (Cyan, Magenta, Yellow) values ​​using a color conversion table 121 as shown in FIG. 5 (step S105).

[0030] The color conversion table 121 used in step S105 is a table for converting the three RGB values ​​of the print data into the ink amounts of each color used for printing (three CMY values), as shown in Fig. 5, for example, and is stored in advance in the storage unit 120. In general full-color image data, each RGB value is expressed in 8 bits (256 levels from 0 to 255), but in this embodiment, each RGB value is expressed in increments of 16 as shown in Fig. 5, thereby suppressing the size (number of data) of the color conversion table 121 to 4096. For RGB values ​​that do not exist in the color conversion table 121, the control unit 110 obtains the corresponding CMY value by interpolating using multiple values ​​that are close to the value and exist in the color conversion table 121.

[0031] It should be noted that even inks of the same color may have different colors depending on the type and lot of the ink. Therefore, a color conversion table 121 that takes into account the color development of each ink may be used. By doing so, it is possible to improve the reproducibility of the printed colors.

[0032] Returning to FIG. 4, the control unit 110 calculates the average value of the pixel values ​​of each color of CMY of the print data converted into CMY values, and sets the average value as the data pixel value of each color (step S106). Here, the data pixel value of C (cyan) is set as dtac, the data pixel value of M (magenta) as dtam, and the data pixel value of Y (yellow) as dtay. Note that this average value (data pixel value) may simply be the average value calculated from the entire print data, but it may also be calculated in a central area (central area) of the nail surface where accurate image data can be easily obtained, or in an area (mixed color area) where colors in which CMY are mixed at a predetermined ratio or more exist. Hereinafter, the area in the image data where the average value of the pixel values ​​of each color is calculated is also referred to as an average calculation area.

[0033] Then, the control unit 110 controls the printing unit 160 to print the printing data of the nail design on the printing medium using each of the three colors of ink (cyan, magenta, and yellow) held in the ink holding unit at the CMY value densities acquired in step S105 (step S107).

[0034] When printing by the printing unit 160 is completed, the control unit 110 photographs the print result with the imaging unit 150 to obtain the imaging data, and converts the RGB values ​​of the pixels of the imaging data into CMY values ​​using the imaging color conversion table 122 (step S108). This conversion to CMY values ​​can be performed in the same manner as in step S105 described above, but whereas the color conversion table 121 is a table that converts the RGB values ​​of the image data for printing into the CMY values ​​of the ink to be printed, the imaging color conversion table 122 is a table that converts the RGB values ​​of the imaging data into the CMY values ​​of the printed ink.

[0035] The imaging color conversion table 122 used in step S108 is a table that converts the RGB values ​​obtained by capturing an image with the camera of the imaging unit 150 to be equal to the CMY values ​​of the print data, as shown in FIG. 6, for example, and is stored in advance in the storage unit 120.

[0036] For example, the RGB values ​​of print data containing as many colors as possible are converted to CMY values ​​using color conversion table 121 and printed, and the RGB values ​​obtained by photographing this with imaging unit 150 are converted to CMY values ​​of the print data to create captured color conversion table 122. However, the LED 152, which is the light source used during photographing, generally has a variation in brightness. Therefore, when the brightness variation is ±d%, the print is photographed at a standard brightness, and the captured color conversion table 122 is created using the RGB values. Then, the maximum value of the variation width of the CMY values ​​when the brightness is varied by ±d% is set to the specified values ​​Δc, Δm, and Δy described later.

[0037] In general full-color image data, each RGB value is represented by 8 bits (256 levels from 0 to 255), but in this embodiment, as with the color conversion table 121, each RGB value is represented in increments of 16 as shown in Fig. 6, thereby suppressing the size (number of data items) of the captured color conversion table 122 to 4096. For RGB values ​​that do not exist in the captured color conversion table 122, the control unit 110 obtains the corresponding CMY value by interpolating using multiple values ​​that are close to that value and exist in the captured color conversion table 122.

[0038] Returning to Fig. 4, the control unit 110 calculates the average value of the pixel values ​​of each color, CMY, of the captured data, and sets the average value as the captured pixel value of each color (step S109). Here, the captured pixel value of C (cyan) is set as prac, the captured pixel value of M (magenta) as pram, and the captured pixel value of Y (yellow) as pray. Note that this average value (captured pixel value) is calculated in an area (area at the same position) corresponding to the area of ​​the print data (average value calculation area) when the average value (data pixel value) was calculated in step S106.

[0039] That is, if the average value was calculated from the entire print data in step S106, the average value is calculated from the entire image data. If the average value was calculated from the central area (central area) of the nail surface in step S106, the average value is calculated from the area corresponding to the central area, i.e., the central area of ​​the nail surface in the image data. If the average value was calculated from the area (mixed color area) where each of CMY is mixed at a predetermined ratio or more in step S106, the average value of the pixel values ​​of each of CMY colors is calculated in the area corresponding to the mixed color area, i.e., in the area of ​​the image data located in the same position as the mixed color area.

[0040] Next, the control unit 110 compares the ratio of the pixel average values ​​of each of CMY in the print data (i.e., the ratio of the data pixel values, dtac:dtam:dtay) with the ratio of the pixel average values ​​of each of CMY in the imaging data (i.e., the ratio of the imaging pixel values, prac:pram:pray) (step S110). Then, the control unit 110 determines whether or not the numerical value of the ratio of the imaging pixel values ​​in the ratio between these three colors is smaller than or larger than a predetermined value (step S111). The method of comparing the ratio between these three colors will be described later.

[0041] If there is no value smaller than a predetermined value or larger than a predetermined value in the ratios among the three colors (step S111; No), the control unit 110 ends the printing process.

[0042] If the ratio between the three colors has a value smaller than a predetermined value or a value larger than a predetermined value (step S111; Yes), the control unit 110 determines that the ink tank of the color with the value smaller than a predetermined value or the ink tank of the color that does not have the value larger than a predetermined value has an abnormality such as running out of ink (step S112). At that time, the control unit 110 may notify the user by displaying on the display unit 130 that the ink tank of that color is out of ink and urge the user to replace the ink tank. Also, the control unit 110 may display the fact that the ink tank is out of ink on the screen of the user's smartphone via the communication unit 170. Then, the control unit 110 ends the printing process.

[0043] Here, a method for comparing the ratios among the three colors in steps S110 and S111 will be described. When making this comparison, the control unit 110 adjusts each numerical value so that the two sets of ratios among the three colors can be compared. Specifically, for example, the least common multiple of the largest value (e.g., prac) among prac, pram, and pray, which are pixel average values ​​(i.e., image pixel values) of the image data (print result), and the corresponding pixel average value (i.e., data pixel value; for example, dtac corresponds to prac) of the print data is found, and each numerical value of the two ratios is adjusted using the value of this least common multiple.

[0044] For example, let the least common multiple be prac2 and dtac2 (for convenience, they are expressed separately, but the values ​​of prac2 and dtac2 are the same). Then, find a ratio that includes these new numerical values ​​prac2 and dtac2 in the same ratio as the two ratios mentioned above. That is, find the ratio of data pixel values ​​dtac:dtam:dtay=dtac2:dtam2:dtay2 and the ratio of captured pixel values ​​prac:pram:pray=prac2:pram2:pray2. If the colors are printed correctly according to the print data, the remaining two sets of values ​​other than the least common multiple will also be the same, that is, dtam2=pram2 and dtay2=pray2.

[0045] If an abnormality such as running out of ink has occurred, these two sets of values ​​will not be the same. For example, if the magenta ink has completely run out, there will be no magenta in the print result, so pram2 = 0. Therefore, if the captured pixel value is smaller than the data pixel value, the control unit 110 can determine that the ink tank of the color corresponding to that captured pixel value is in an abnormal state, such as running out of ink, having a low ink amount, or being clogged with ink.

[0046] However, even if the ink amounts in the ink tanks of each color are normal, differences may generally exist between the data pixel values and the captured pixel values due to the influence of the values in the imaging color conversion table 122 that converts the RGB values of the captured data to CMY values, the influence of the lighting conditions during shooting, and so on. Therefore, specified values Δc, Δm, and Δy for each color (CMY) are set to absorb such differences, and when the difference exceeds this specified value, it is determined that an abnormality such as out-of-ink has occurred in the ink tank of that color.

[0047] That is, for example, in the case of pram2 where dtam2 - Δm > pram2, it is determined that the magenta ink has an abnormality such as out-of-ink. Here, specified values Δc, Δm, and Δy that are determined by the difference are set as the specified values, but specified values pc, pm, and py that are determined by the ratio may be set, and for example, in the case of pram2 where dtam2 / pram2 > pm, it may be determined that the magenta ink has an abnormality such as out-of-ink.

[0048] Also, in the above example, since prac was the largest value among the numerical values prac, pram, and pray of the ratio of the captured pixel values (that is, the captured pixel value of the cyan ink was the largest), the ratio value was adjusted based on cyan. However, if the cyan ink is abnormal and the original ink amount was not printed even though the captured pixel value of the cyan ink is the largest, the ratio values of the inks other than cyan will increase, and dtam2 + Δm < pram2, dtay2 + Δy < pray2 will result. Therefore, in such a case, it is determined that the cyan ink used as the reference has an abnormality such as out-of-ink. Regarding this as well, instead of the specified values Δc, Δm, and Δy, specified values pc, pm, and py may be set, and when dtam2 / pram2 < pm, dtay2 / pray2 < py, it may be determined that the cyan ink has an abnormality such as out-of-ink.

[0049] To sum up, when the captured pixel value is smaller than the data pixel value by a predetermined amount for a color other than the reference color (cyan in the above example), the control unit 110 can determine that the ink tank of the color corresponding to the captured pixel value has run out of ink or other abnormality. When the captured pixel value is larger than the data pixel value by a predetermined amount for a color other than the reference color, the control unit 110 can determine that the ink tank of the reference color has run out of ink or other abnormality.

[0050] Then, for colors other than the reference color (cyan in the above example), if the data pixel value is not 0 but the image pixel value is 0, the control unit 110 can determine that the ink tank of that color is completely empty. If the image pixel value is smaller than the data pixel value by a predetermined amount but is not 0, the control unit 110 can determine that there is still a small amount of ink remaining in the ink tank of that color, but that the ink is getting too low (a state in which the original amount of ink cannot be ejected).

[0051] In the above comparison method, if all inks are decreasing at the same rate, the numerical value of the ratio of the captured pixel values ​​may be almost the same as when the ink is normal, and in this case, a correct judgment cannot be made. However, it is rare for all inks to decrease at the same rate, and in most cases there is a bias in the ink consumption. For this reason, there are usually no problems with the above comparison method.

[0052] As described above, in the first embodiment, the control unit 110 can determine the state of the ink tank based on the result of comparing the print data with the print result.

[0053] (Embodiment 2) As described in the comparison method in steps S110 and S111 of the printing process (FIG. 4) above, in the first embodiment, the ratio of the three colors is adjusted based on the ink with the highest density in the captured data. Normally, if the captured pixel value of an ink other than the reference ink is smaller than a preset value or more, the control unit 110 can determine that the ink tank of that ink is out of ink or has an abnormality. However, there may be cases where the captured pixel value is maximum even though the ink is low (because the density in the print data is high). In this case, the control unit 110 adjusts the ratio of the three colors based on the ink that is low. In this case, if the captured pixel value of an ink other than the reference ink is larger than a preset value or more, the control unit 110 needs to determine that the ink tank of the reference ink is out of ink or has an abnormality. In this way, in the first embodiment, it becomes necessary to determine both cases where the captured pixel value is smaller than a preset value and cases where the captured pixel value is larger than a preset value. A second embodiment that can avoid such a determination will be described.

[0054] As shown in FIG. 1, the functional configuration of a printing device 101 according to the second embodiment is similar to that of the printing device 100 according to the first embodiment, and only the content of the printing process executed by a control unit 110 is different.

[0055] The print processing according to the second embodiment will be described with reference to Fig. 7. As in the first embodiment, when a user instructs the printing device 101 to print, execution of the print processing starts.

[0056] The processing from step S201 to step S209 is similar to the processing from step S101 to step S109 in the printing process (FIG. 4) according to the first embodiment, and therefore a description thereof will be omitted.

[0057] In step S210, the control unit 110 sets the color (cyan, magenta, or yellow) that has the maximum value among the data pixel values ​​of each of CMY to A, and sets the data pixel value of color A to Av. Then, the control unit 110 sets the captured pixel value of color A to Apv (step S211). However, even if the ink amounts of all three colors are normal, the captured pixel value Apv and the data pixel value Av will generally differ in value. Therefore, a specified value Δcmy is set so that if the difference between the captured pixel value Apv and the data pixel value Av is within the specified value, they are considered to be the same.

[0058] That is, as explained in the first embodiment, the captured color conversion table 122 that converts the RGB values ​​obtained by photographing with the camera of the imaging unit 150 to be equal to the CMY values ​​of the print data is created in advance and stored in the storage unit 120, and in step S208, the captured color conversion table 122 is used to convert the captured data to CMY values, but since the LED 152, which is the light source used during photographing, has brightness variations, when the brightness variation is ±d%, the print is photographed at a standard brightness and the RGB values ​​are used to create the captured color conversion table 122. Then, the average (or maximum) of the fluctuation range of the CMY values ​​when the brightness is varied by ±d% is set to the specified value Δcmy.

[0059] Then, the control unit 110 judges whether the captured pixel value Apv is smaller than the data pixel value Av by a specified value Δcmy or more (i.e. Av-Δcmy>Apv) (step S212). If the captured pixel value Apv is smaller than the data pixel value Av by the specified value Δcmy or more (step S212; Yes), the control unit 110 judges that the ink tank of color A has an abnormality such as running out of ink (step S213). At that time, the control unit 110 may notify the user by displaying on the display unit 130 that the ink tank of color A is out of ink, and urge the user to replace the ink tank. Also, the control unit 110 may display the fact that the ink tank of color A is out of ink on the screen of the user's smartphone via the communication unit 170. Then, the control unit 110 ends the printing process.

[0060] If the captured pixel value Apv is not smaller than the data pixel value Av by the specified value Δcmy or more (step S212; No), the control unit 110 proceeds to step S214. The process of step S214 is similar to the process of step S110 in the printing process (FIG. 4) of the first embodiment. The control unit 110 then determines whether or not the numerical value of the ratio of the captured pixel values ​​in the ratios among these three colors is smaller than a predetermined value (step S215). The method of comparing the ratios among these three colors is as described above for the method of comparing the ratios among the three colors in steps S110 and S111 of the first embodiment.

[0061] If there is no value smaller than a predetermined value in the ratio among the three colors (step S215; No), the control unit 110 ends the printing process.

[0062] If the ratio between the three colors has a value smaller than a predetermined value (step S215; Yes), the control unit 110 determines that the ink tank of the color with the value smaller than the predetermined value has an abnormality such as being out of ink (step S216). At that time, the control unit 110 may display on the display unit 130 that the ink tank of that color is out of ink to notify the user and encourage them to replace the ink tank. The control unit 110 may also display the out-of-ink message on the screen of the user's smartphone via the communication unit 170. Then, the control unit 110 ends the printing process.

[0063] In steps S212 and S213, instead of setting a specified value of the difference Δcmy, a specified value of the ratio pcmy may be set so that if Av / Apv>pcmy, it is determined that the ink tank of color A has an abnormality such as being out of ink. Also, the value of Apv in the out-of-ink state may be set as Aoff, and if Apv is Aoff or less, it may be determined that the ink tank of color A has an abnormality such as being out of ink.

[0064] Also, in step S210 of the printing process described above (FIG. 7), the control unit 110 determines the ink amount for color A, which is the color (cyan, magenta, or yellow) that has the maximum value among the data pixel values ​​of each of CMY, and thereafter determines the ink amount based on the ratio among the three colors, as in the first embodiment. However, in steps S210 to S212, the ink amount of color A that has the maximum value among the data pixel values ​​is determined, and if there is no problem with the ink amount of color A (step S212; No), the ink amount of color A2 that has the second largest value among the data pixel values ​​is determined, and if there is no problem with the ink amount of color A2, the ink amount of color A3 that has the smallest value among the data pixel values ​​is determined. When making such a determination, it is no longer necessary to determine the ink amount based on the ratio among the three colors.

[0065] However, if the data pixel value Av is less than a predetermined lower limit (for example, Δcmy) (i.e. Av<Δcmy), step S212 will always be No, making it difficult to make a correct determination. Therefore, a predetermined lower limit value equal to or greater than Δcmy may be set for the data pixel value Av, and the ink amount may be determined if Av is equal to or greater than the lower limit, but the ink amount may not be determined if Av is less than the lower limit.

[0066] If the data pixel value Av is below a specified lower limit, even if the print data is printed when the ink runs out, the color of the printed result is not significantly affected. Therefore, in most cases, it is considered that there is no problem even if the ink amount is not determined when Av is below the lower limit.

[0067] By the printing process described above, the control unit 110 of the printing device 101 can determine the status of the ink tank based on the result of comparing the print data with the print result. Furthermore, in the second embodiment, the status of the ink tank for color A, which has the maximum pixel value (highest density) among CMY, is determined first, so that the status of the ink tank can be correctly determined even if all inks are decreasing at the same rate.

[0068] (Embodiment 3) In the above-described embodiment, it was assumed that the base color of the printing medium (the color of the nail or the nail tip before printing) was white or a color close to white. When printing on nails, it is normal to apply a white base ink to the nail and then print the nail design, and nail tips are usually white, so there is no particular problem with this assumption. However, it cannot be said that there are no cases where printing is performed on a base other than white, and in such cases, the image pixel value is affected by the base color. Therefore, a third embodiment will be described, which can correctly determine the state of the ink tank even when the base is not white or not close to white.

[0069] As shown in FIG. 1, the functional configuration of a printing device 102 according to the third embodiment is similar to that of the printing device 100 according to the first embodiment, and only the content of the printing process executed by the control unit 110 is different.

[0070] The print processing according to the third embodiment will be described with reference to Fig. 8. As in the first embodiment, when a user instructs the printing device 101 to print, execution of the print processing starts.

[0071] The processes from step S301 to step S303 in the printing process (FIG. 8) according to the third embodiment are similar to the processes from step S101 to step S103 in the printing process (FIG. 4) according to the first embodiment, and therefore description thereof will be omitted.

[0072] In step S304, the control unit 110 converts the RGB values ​​of the image data of the print medium acquired in step S303 into CMY values ​​using the captured color conversion table 122, and sets the converted data as background data.

[0073] The processes from step S305 to step S309 are similar to the processes from step S104 to step S108 in the printing process (FIG. 4) according to the first embodiment, and therefore a description thereof will be omitted.

[0074] In step S310, the control unit 110 calculates the average value of the pixel values ​​of each color of CMY in the image data and the average value of the pixel values ​​of each color of CMY in the background data, and determines the image pixel value by subtracting the average value of the pixel values ​​of the background data from the average value of the pixel values ​​of the image data. In other words, if the area (area in the image data) where the average value is calculated when calculating the image pixel value is set as the average calculation area, then for each color of CMY, Image pixel value = average value in average calculation area of ​​pixel values ​​of image data - average value in average calculation area of ​​pixel values ​​of background data It becomes.

[0075] The processing from step S311 to step S313 is similar to the processing from step S110 to step S112 in the printing process (FIG. 4) according to the first embodiment, and therefore a description thereof will be omitted.

[0076] With the printing process described above, the control unit 110 of embodiment 3 subtracts the pixel values ​​of the background data from the pixel values ​​of the imaging data before comparing them with the pixel values ​​of the print data, thereby reducing the influence of the background color and enabling a more accurate determination of the state of the ink tank.

[0077] (Modification) Although the embodiment of the present invention has been described above, the above-mentioned embodiment is merely an example, and the scope of application of the present invention is not limited thereto. In other words, the embodiment of the present invention can be applied in various ways, and all embodiments are included in the scope of the present invention.

[0078] For example, it is possible to combine the second and third embodiments by performing step S304 of the printing process of the third embodiment (FIG. 8) immediately after step S203 of the printing process of the second embodiment (FIG. 7) described above, and performing step S310 instead of step S209. By doing so, the ink tank status can be correctly determined even when all inks are running low at the same rate, and since the effect of the background color can be reduced, the ink tank status can be determined even more correctly.

[0079] In the above embodiment, the ink holding unit 164 is described as having ink tanks of three colors, CMY (cyan, magenta, yellow), but the inks used for printing do not have to be limited to the three colors of CMY. For example, if a black (K) ink tank is also provided in addition to these, the control unit 110 can determine the status of the ink tanks, including the black ink, by similar printing processing by storing a color conversion table 121 and an image color conversion table 122 in the storage unit 120 that convert RGB values ​​to CMYK values.

[0080] In addition, in addition to the three colors of ink, CMY, or the four colors of ink, CMYK, if a color conversion table 121 and an imaged color conversion table 122 corresponding to the ink tanks equipped in the printing devices 100, 101, and 102 are stored in the storage unit 120 and conversion is performed using the color conversion table 121 and the imaged color conversion table 122 in the printing process, it is possible to support ink tanks of other colors.

[0081] Furthermore, if the nail design to be printed is designed in relatively light colors overall, the data pixel values ​​obtained by averaging the entire print data may all be below a specified value, in which case the control unit 110 will be unable to determine the state of the ink tank. Therefore, the control unit 110 may extract a dark area (high density area) from the print data, obtain the data pixel value from the extracted high density area, and also obtain the image pixel value from the high density area.

[0082] In addition, there is no problem if the areas for obtaining the data pixel values ​​and the image pixel values ​​are different for each color. Therefore, the control unit 110 may extract areas for each of the colors CMY where that color is used frequently from the print data (i.e., areas where cyan is used frequently, areas where magenta is used frequently, and areas where magenta is used frequently), and obtain the data pixel values ​​and image pixel values ​​of that color by obtaining the average value of the pixel values ​​of each color from the extracted areas where each color is used frequently.

[0083] In the above embodiment, the color conversion table 121 is used when converting the RGB values ​​of the print data to CMY values, but a formula for converting the RGB values ​​to CMY values ​​may be used. When the control unit 110 converts the RGB values ​​to CMY values ​​using a formula, the storage unit 120 does not need to store the color conversion table 121. It is considered difficult to define a normal formula for the captured color conversion table 122 because it is affected by the color development of the ink, the characteristics of the camera of the image capture unit 150, the characteristics of the lighting, etc., but it is possible to have a function similar to that of the captured color conversion table 122 by learning the RGB values ​​and CMY values ​​of various captured data using a neural network, etc. Of course, the color conversion table 121 may also be replaced with one that has been learned using a neural network, etc., instead of the normal formula.

[0084] In the above embodiment, the print medium is described using nails and nail tips as examples, but the print medium is not limited to these and may be paper, for example. In particular, if the print medium is white, such as white paper, the control unit 110 can more accurately determine the state of the ink tank without being affected by the color of the background. Conversely, when printing on a colored print medium, it is desirable to execute the print process with the printing device 102 according to the above-mentioned third embodiment in order to reduce the influence of the coloring.

[0085] In the above embodiment, the printing devices 100, 101, and 102 are inkjet nail printers equipped with ink tanks of multiple colors, but the printing device is not limited to inkjet nail printers equipped with ink tanks of multiple colors. For example, the present invention can be applied to color laser printers equipped with toner cartridges of multiple colors, and also to printers that print on normal paper. In other words, if the printing device uses ink of multiple colors, the control unit 110 can determine the status of the ink tanks by a printing process similar to that described above.

[0086] However, since nail printers usually need to recognize the shape of the print medium (nail, nail tip, etc.), obtain the print area, and correct the nail design as necessary, they are equipped with an imaging unit 150 that images the print medium. Therefore, with a nail printer, the imaging unit for obtaining the print area can be used to image the print medium after printing (obtain image data), and there is an advantage in that there is no need to provide a new device separately.

[0087] If the printing device, such as a normal printer, does not have an imaging unit 150, the print result can be photographed with a camera of another device (e.g., a digital camera, a smartphone, a tablet terminal, etc.), and the photographed image can be transferred via the communication unit 170 so that the control unit 110 acquires the image data.

[0088] In the above embodiment, the CPU of the control unit 110 executes the program stored in the storage unit 120 to control each unit of the printing devices 100, 101, 102. However, in the present invention, the control unit 110 may include dedicated hardware such as an ASIC (Application Specific Integrated Circuit), an FPGA (Field-Programmable Gate Array), and various control circuits instead of a CPU, and the dedicated hardware may control each unit of the printing devices 100, 101, 102. In this case, each function of the control unit 110 may be realized by individual hardware, or each function may be collectively realized by a single piece of hardware. Also, some of the functions may be realized by dedicated hardware, and the other parts may be realized by software or firmware.

[0089] Furthermore, the printing devices 100, 101, and 102 may not be a single device, but may be separated into a control device (e.g., a PC, a smartphone, a tablet, or the like, equipped with a control unit 110, a storage unit 120, a display unit 130, an operation input unit 140, and a communication unit 170) and a printing device (equipped with an imaging unit 150, a printing unit 160, and a communication unit 170). In this case, the above-mentioned printing process is performed by the control unit 110 of the controlling device, and it is possible to obtain an image of the printing medium obtained by the imaging unit 150 of the printing device via the communication unit 170, and to instruct the printing unit 160 to print.

[0090] Although the above describes a preferred embodiment of the present invention, the present invention is not limited to the specific embodiment, and the present invention includes the invention described in the claims and its equivalents. [Explanation of symbols]

[0091] 100, 101, 102...printing device, 110...control unit, 120...storage unit, 121...color conversion table, 122...captured color conversion table, 130...display unit, 140...operation input unit, 148...finger rest, 149...finger holding unit, 150...capture unit, 151...camera, 152...LED, 160...printing unit, 161...print head, 162...X-axis driving unit, 163...Y-axis driving unit, 164...ink holding unit, 170...communication unit, 201...finger, 202...nail

Claims

1. A plurality of ink tanks for holding ink; A printing unit that applies the ink to a print medium; an imaging unit that images the printing medium; A control unit, The control unit is Obtaining pixel values ​​in the print data to be printed on the print medium as data pixel values; Controlling the printing unit so as to print on the print medium based on the print data; The printing medium printed by the printing unit is imaged by the imaging unit to obtain imaging data; A pixel value in the imaging data is acquired as an imaging pixel value; determining a state of the ink tank based on a comparison result between the data pixel value and the captured pixel value; Printing device.

2. The control unit is An average value of each pixel value of CMY in the print data is obtained as the data pixel value; an average value of each of the CMY pixel values ​​in the imaging data is obtained as the imaging pixel value; The printing device of claim 1 .

3. The control unit is an average value of pixel values ​​of each of CMY in a mixed color area, which is an area where a color in which each of CMY of the print data is mixed at a predetermined ratio or more exists, is obtained as the data pixel value; obtaining an average value of each of the pixel values ​​of CMY in an area of ​​the imaging data corresponding to the mixed color area as the imaging pixel value; The printing device according to claim 2 .

4. The control unit is determining whether or not any of the ink tanks is out of ink based on a comparison result between the data pixel value and the captured pixel value; The printing device according to claim 3 .

5. Further comprising a notification unit, The control unit is When it is determined that any one of the ink tanks has run out of ink, the notification unit notifies the user that the ink tank has run out of ink. The printing device according to claim 4.

6. the printing medium is a nail, The control unit is A pixel value in a central region of the print data, which is a central region of the surface of the nail, is acquired as the data pixel value; acquiring, as the imaged pixel value, a pixel value in a region of the imaging data corresponding to the central region; The printing device according to any one of claims 1 to 5.

7. The control unit is Before printing by the printing unit, the printing medium is imaged by the imaging unit to obtain background data; Calculating the captured pixel value by subtracting the pixel value in the base data from the pixel value in the captured data; The printing device according to claim 6.

8. A printing control method for a printing device having an ink tank, a printing unit, an imaging unit, and a control unit, comprising: The control unit: A pixel value in the print data to be printed on the print medium is obtained as a data pixel value; Controlling the printing unit so as to print on the print medium based on the print data; The printing medium printed by the printing unit is imaged by the imaging unit to obtain imaging data; A pixel value in the imaging data is acquired as an imaging pixel value; determining a state of the ink tank based on a comparison result between the data pixel value and the captured pixel value; Printing control method.

9. A printing device including an ink tank, a printing unit, an imaging unit, and a control unit, the control unit being provided with: A pixel value in the print data to be printed on the print medium is obtained as a data pixel value; Controlling the printing unit so as to print on the print medium based on the print data; The printing medium printed by the printing unit is imaged by the imaging unit to obtain imaging data; A pixel value in the imaging data is acquired as an imaging pixel value; determining a state of the ink tank based on a comparison result between the data pixel value and the captured pixel value; The program that performs the processing.

Images