JP2016210082A - Printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a printer which can perform three-dimensional expression of an image with existing equipment in various patterns without introducing a new mechanism.SOLUTION: A printer comprises: medium conveyance means 5 which conveys a printing medium Pa; ribbon conveyance means 4 which is sheet conveyance means for conveying an ink ribbon Pb formed with a protective layer for thermal transfer on an image printed on the printing medium Pa; a thermal head 2 in which heater elements 3 are arrayed in the main-scanning direction orthogonal to the conveyance direction of the printing medium Pa; and control means 1 which performs drive control of the medium conveyance means 5, ribbon conveyance means 4 and thermal head 2. The control means 1 is configured to perform heating to the ink ribbon Pb with a reference heat quantity when the protective layer is transferred to a background region on the outer side of an outline region outlining the image on the basis of the image data used for outlining the image, and perform heating to the ink ribbon Pb by changing the heat quantity to the low heat quantity or high heat quantity side with respect to the reference heat quantity when the protective layer is transferred to the outline region.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a printer having a function of transferring a protective layer for protecting an image.

  A thermal printer is a device that prints on a printing medium by transferring a dye or a pigment to a recording medium such as paper through heating control of a heating element of a thermal head.

  Attempts have been made to express images such as photographs three-dimensionally for such a thermal printer.

  For example, a pressure roller is provided, and the paper is physically crushed by the pressure roller so as to be uneven (Patent Document 1).

  Alternatively, the sheet body heating unit that heats the sheet body and the sheet body cooling unit that cools the sheet body in a state where the sheet body is in contact with the contact member, the surface of the sheet body is formed by the sheet body heating unit. There is also known one that imparts surface properties according to image information (Patent Document 2).

  Further, when forming a concavo-convex pattern on the printing medium by selectively changing the thermal energy to the heating element of the thermal head on the protective layer thermally transferred onto the image formed on the printing medium, A heating element array is randomly divided into heating element groups composed of at least two adjacent heating elements, and the same thermal energy is applied to the heating elements constituting the heating element group, so that adjacent heating element groups There is also known a technique in which different thermal energy is applied to produce a silky texture (Patent Document 3).

JP 05-53288 A JP 2005-219388 A JP 2009-137116 A

  However, the thing of patent document 1 requires the function of a press part other than a printing mechanism, and while causing the structure large size, complexity, and cost increase, and pressurization is dependent on the shape of a roller, arbitrary unevenness | corrugation There is a difficulty that can not be attached.

  In addition, the one in Patent Document 2 requires two mechanisms, a heating part and a cooling part of the sheet body, which also increases the size and complexity of the structure and increases the cost, and also has only two parts, a glossy part and a matte part. There is a difficulty that cannot be expressed.

  Furthermore, Patent Document 3 requires a memory having a capacity capable of storing one piece of image data, and is based on the repetition of the minimum pattern, and has a low degree of freedom of changing the expression according to the background. There is a difficulty.

  The present invention has been made paying attention to such problems, and a printer capable of variously expressing images three-dimensionally with existing equipment without introducing a new mechanism separately. It is intended to provide.

  In order to achieve this object, the present invention takes the following measures.

  That is, the printer of the present invention includes a medium conveying unit that conveys a printing medium, a sheet conveying unit that conveys a thermal transfer sheet on which a protective layer is formed on the image printed on the printing medium, and a printing medium. The apparatus includes a thermal head in which heating elements are arranged in a main scanning direction orthogonal to the conveyance direction, and a control unit that drives and controls the medium conveyance unit, the sheet conveyance unit, and the thermal head. Based on the image data used for printing, when transferring the protective layer to the background area outside the outline area where the image is drawn, the thermal transfer sheet is heated with a reference heat amount, and when transferring the protective layer to the outline area The heat transfer sheet is configured to be heated by changing the heat amount to a lower heat amount or a higher heat amount side than the reference heat amount.

  In this way, the higher the heating amount, the rougher the surface of the protective layer and the lower the light reflectance, resulting in a matte tone. The lower the amount of heating, the better the surface of the protective layer and the light reflectance. As a result, the glossiness becomes high. At this time, the matte tone seems to be depressed on the back side, and the glossy part appears to be raised on the near side. As described above, according to the present invention, it is possible to perform a three-dimensional representation of the image in a state in which the contour region is raised or depressed from the background by using a difference in calorie without adding a separate mechanism. It can be expressed in various ways according to the image.

  Alternatively, the printer of the present invention includes a medium conveying unit that conveys a printing medium, a sheet conveying unit that conveys a thermal transfer sheet on which a protective layer is formed on the image formed on the printing medium, and a sheet conveying unit. A thermal head in which heating elements are arranged in a main scanning direction orthogonal to the conveyance direction, and a medium conveyance unit, a sheet conveyance unit, and a control unit that drives and controls the thermal head, wherein the control unit prints an image. When the protective layer is transferred to the background area outside the contour area where the image is drawn based on the image data used for the heating, the thermal transfer sheet is heated with a reference heat amount, and the protective layer is applied to the image area inside the contour area. When transferring, the heat transfer sheet is heated by changing the amount of heat to a lower or higher amount of heat than the reference heat amount. It may be.

  In this way, it is possible to perform a three-dimensional representation of the image in a state where the image area is raised or depressed from the background, and the representation can be performed in various ways according to the image. .

  Further, the control means may heat the thermal transfer sheet by changing the heat amount for both the outline region and the image region with reference to the background region.

  In order to express the depressed state or the raised state unnaturally, the calorific value data of the region adjacent to the contour region may be changed in a stepwise manner from the contour region to the adjacent region. desirable.

  In order to appropriately correspond to an arbitrary image, the control unit includes an image data acquisition unit that acquires image data, a contour extraction unit that extracts a contour region from the acquired image data, and a region extracted by the contour extraction unit A heat quantity data generation unit that generates heat quantity data for transfer of the protective layer based on the image data, and the contour extraction unit outlines both end positions of a region in which dot data corresponding to the pixels of the image data continues for a predetermined pixel or more. The heat amount data generation unit generates heat amount data for each pixel for a predetermined region based on the contour region extracted by the contour extraction unit, and drives the thermal head based on the heat amount data to control the thermal transfer sheet. It is desirable to be configured so as to heat.

  In the case where the image data is a fixed form, etc., the image data acquisition means acquires the heat amount data for transfer of the protective layer for each pixel associated with the image data in the corresponding area along with the acquisition of the image data, The control means is preferably configured to heat the thermal transfer sheet by driving and controlling the thermal head based on the heat quantity data.

  According to the present invention described above, it is possible to change the heat amount data for heating the thermal transfer sheet in the existing equipment, without affecting the color of the underlying image without introducing a new mechanism. Therefore, it is possible to provide an excellent printer that makes it possible to realize appropriate depth expression and perspective for images such as backgrounds, people, and characters.

FIG. 2 is a schematic plan view showing the vicinity of a thermal head of a printer according to an embodiment of the present invention. FIG. 2 is a block diagram illustrating a configuration of the printer. Explanatory drawing of the ink ribbon used for the printer. The hardware block diagram which comprises the control means of the printer. 6 is a flowchart for explaining a print control routine of the printer. OP printing image diagram by the printer. The figure which shows the outline extraction principle of the printer. The figure which shows the outline extraction principle of the printer. The figure which shows the heat amount data generation principle of the printer. The figure which shows the heat amount data generation principle of the printer. The figure corresponding to FIG. 9 which shows the other aspect of calorie | heat amount data generation. The figure corresponding to FIG. 2 which shows the modification of this invention. The figure corresponding to Drawing 10 showing other modes of calorie data generation.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

  As shown in FIGS. 1 and 2, a thermal printer 1 as a printer of this embodiment includes a thermal head 2 in which a plurality of heating elements 3 that generate heat when energized are arranged to form one line, A medium conveying means 5 for supplying a printing medium Pa such as paper or resin to the thermal head 2, and a ribbon conveying means 4 as a sheet conveying means for supplying an ink ribbon Pb, which is a thermal transfer sheet coated with a dye or pigment, to the thermal head 2; And control means 1. In this embodiment, the arrangement direction of the heat generating elements 3 is referred to as a main scanning direction, and the paper feeding direction orthogonal to the main scanning direction is referred to as a sub scanning direction.

  The heat generating element 3 is provided corresponding to each pixel constituting one line in the main scanning direction of the print area in the print medium Pa, and transfers the dye or pigment of the ink ribbon Pb to the print medium Pa by heat generated by energization. In this case, printing is performed on the corresponding pixel of the print data, and the print medium Pa is moved in the sub-scanning direction together with the ink ribbon Pb to be supplied in the print direction set to any one of the sub-scan directions. The pixels are printed in order along the line.

  For example, in this embodiment, as shown in FIG. 3, an ink ribbon Pb in which three primary colors of Y (yellow), M (magenta), and C (cyan) are arrayed is used. Is expressed on the printing medium Pa. Further, following these three primary colors, an OP layer (overcoat layer) as a protective layer is formed. The “print data” in this specification refers to data necessary for color printing, in other words, data necessary to print a background image before OP layer transfer, and includes monochrome print data. .

  Then, the head driving circuit 61, the energizing circuit 62, the ribbon driving circuit 63, and the paper feed driving circuit 64 cooperate to implement a printing operation in response to a command from the control unit 1 shown in FIG. FIG. 4 shows the basic configuration of the control means 1. The control means 1 includes at least a CPU 11, a ROM 12, a RAM 13, and an interface (I / F) 14. The I / F 14 includes the head drive circuit 61, the energization circuit 62, the ribbon shown in FIG. 2 as peripheral hardware resources. In addition to the drive circuit 63 and the paper feed drive circuit 64, necessary elements are connected, and the ROM 12 stores at least a print control routine as a program necessary for printing.

  The CPU 11 calls and executes a print control routine stored in the ROM 12 as necessary, and cooperates with peripheral hardware to perform image data acquisition unit 15, print control unit 16, protective layer (OP layer) transfer data shown in FIG. It plays a role as the generation unit 17.

  The image data acquisition unit 15 stores in the RAM 13 print data input from the outside in response to a print command. This print data includes gradation values and color data as heat quantity data given to each pixel (dot) to be printed.

  As shown in FIG. 5, the print control unit 16 performs yellow print processing S1, magenta print processing S2, and cyan print processing S3 as shown in FIG. 5, and then performs OP print processing S4. The printing medium Pa is cut and discharged S5 through the medium cutting means and the discharging means, and printing is terminated.

  The basic routine will be described. The image data of the first line where Y color print data exists along the sub-scanning direction shown in FIGS. 1 and 2 is called, and the corresponding line of the print medium Pa is sent through the paper feed drive circuit 64. The print head is transported to the printing position facing the heating element 3 of the thermal head 2 and the head (or a predetermined position) of the Y color area of the ink ribbon Pb is sent to the printing position by the heating element 3 of the thermal head 2 through the ribbon drive circuit 63. Thus, the head drive circuit 61 heads down the thermal head 2 and the energization circuit 62 generates energization pulses corresponding to the gradations specified for each pixel constituting the line, thereby generating the heating element 3 corresponding to the pixel. Turn on the power. When the energization is completed, the printing medium Pa and the ink ribbon Pb are conveyed by one line or a necessary line in the sub-scanning direction, and image data acquisition, energization pulse generation, and energization are performed for the next line. Such an operation is repeated, and the printing for the Y color print data included in one page is completed. Thereafter, the process proceeds to the M color print, the image data of the first line where the M color print data exists is called up, the thermal head 2 is raised, the corresponding line of the print medium Pa is returned to the print position, and the ink ribbon Pb The head of the M color area (or a required position) is sent to the printing unit by the heating element 3 of the thermal head 2, and after the thermal head 2 is headed down, the energization pulse is generated while the printing medium Pa and the ink ribbon Pb are being sent. 3 is energized. Thereafter, an image corresponding to the image data is realized on the print medium Pa by superimposing dyes or pigments of up to Y, M and C colors through the same operation.

  The basic routine of the OP layer is the same as described above, but here, the image data acquired by the image data acquisition unit 15 is not used, but the OP data is transferred to the protective layer transfer data generation unit 17 using the image data. Heat quantity data is generated, and printing is performed using the heat quantity data. As shown in FIG. 6 as an OP image image diagram, the amount of heat data in this embodiment is such that the contour region A1 that draws a figure is depressed (dark state) and the inner image region A2 is raised with respect to the outer background region A3. It is generated as data representing a stereoscopic image. For this purpose, the protective layer transfer data generation unit 17 shown in FIG. 2 extracts a contour from the acquired image data, a contour extraction unit 17a, and a contour region A1, a background region A3 based on the contour extracted by the contour extraction unit 17a, A heat quantity data generation unit 17b that generates heat quantity data for OP with respect to pixels at necessary portions in the image area A2 is provided.

  The contour extraction unit 17a extracts a region where pixels (dots) to be printed by image data are continuous for a predetermined pixel or more, and uses the region as an extraction target. For example, in the “TEST” printing example of FIG. 7, if the main scanning direction is called a row and the sub-scanning direction is called a column as necessary, the column to be printed by the Xth heating element 3 along the main scanning direction. It is detected that the pixels in the direction are continuous from the Yth row to the Y + bth row in the sub-scanning direction. Then, it is determined whether or not b (or b + 1) is equal to or greater than a predetermined dot (for example, 120 dots). A portion that is less than the predetermined dot is a narrow region and is not extracted because a visual effect cannot be expected even if it is shaded. If it is determined that the dot is equal to or larger than the predetermined dot, a predetermined dot width including both end dots (Y, Y + b) is set in the contour area A1, as shown in FIG. In the example of FIG. 7, such a contour region A1 continues from the Xth column to the X + ath column in the main scanning direction, and therefore, the portion where the contour region A1 is continuous in the line direction is above “T”. It is recognized as a pair of upper and lower contour lines that draw a horizontal line.

  When such a contour area A1 is extracted, the heat quantity data generation unit 17b generates heat quantity data for the pair of contour areas A1, A1 inside the area A1, and the background area A3 outside as shown in FIG. To do. In the heat quantity data generation of this embodiment, a mode for embossing an image and a mode for depression of an image can be selected through an input unit (not shown) connected to the I / F 14 shown in FIG. Now, the description will proceed on the assumption that the mode for embossing the image is selected. In this case, as shown in FIG. 9, the background area A3 is set as a reference heat quantity, the outline area A1 is set to a high heat quantity, and the image area A2 is set to a low heat quantity, and stepwise between the area A1 → A2 and between A1 → A3. The calorific data with the calorific value changed is generated. For example, assuming that the gradation of heat quantity data is from 0 gradation to 255 gradation, the background area A3 is set to 100 gradations, the contour area A1 is set to 120 gradations, and the image area A2 is set to 50 gradations. As shown in FIG. 10 in which part C of FIG. 9 is enlarged, the contour area A1 has 120 gradations over 5 dots, and from there to the image area A2, the image area is lowered by 5 gradations every 3 dots. The process is connected to 50 gradations, which is the set heat amount of A2, and connected to 100 gradations, which is the reference heat amount of the background area A3, while the background area A3 is lowered by 3 gradations every 5 dots.

  The higher the gradation, that is, the higher the heating amount, the rougher the surface of the OP layer and the lower the light reflectance. As a result, the lower the heating amount, the better the OP layer surface and the higher the light reflectance. As a result, a glossy appearance is obtained. At this time, the matte tone seems to be depressed on the back side, and the glossy part appears to be raised on the near side.

  As a result, the horizontal line portion of “T” in FIG. 7 is depressed (darkened) in the outline area A1 with respect to the background area A3 as shown in part A in FIG. 6, and the inner image area A2 is embossed with respect to the background area A3. The OP layer is transferred in the highlighted state (becomes bright).

  In this case, since the outline is not picked up at the end portion (both ends in the longitudinal direction) of the horizontal line portion of “T” shown in FIG. 7, the shading processing as in the B portion in the image diagram of FIG. 6 is not performed.

  Therefore, also in the main scanning direction, in the same manner as described above, both ends of a dot continuous region are detected by the contour extracting unit 17a, and the contour region A1 is set as a high heat amount by using the background region A3 as a reference heat amount by the heat amount data generating unit 17b. In addition, if the heat quantity data is generated by changing the heat quantity stepwise between the areas A1-A2 and A1-A3 by setting the image area A2 to a low heat quantity, the D part at the end of the horizontal line T shown in FIG. The contour area A1 of the image is dull and dark (dark) like the B part of the image diagram of FIG. 6, and the inner image area A2 (between the D part and D part) is more embossed than the background area A3. The OP layer is transferred when it becomes brighter

  At this time, each pixel of the image area A2 is given two amounts of heat data generated by the process in the sub-scanning direction and heat data generated by the process in the main-scanning direction. The contour of the end portion in the main scanning direction (D portion in FIG. 7) becomes brighter. If priority is given to the main scanning direction, the contour of the end portion in the sub scanning direction (E portion in FIG. 7) becomes brighter. Therefore, in order to raise only the inner image area A2 in the matte state for both the D part and the E part, the heat quantity data obtained through contour detection in both the main and sub scanning directions is used. What is necessary is just to perform the appropriate process for satisfying both. As an example of processing, if the higher one (the one in which the matte state is entered) is selected from the calorie data obtained through contour detection in both the main and sub scanning directions, the end portion D in the main scanning direction shown in FIG. Both the end portion E in the sub-scanning direction can make the contour region A1 dented in a matte tone so that both the expression of the state of brightening as it goes to the center of the image region A2 can be achieved. Of course, the method of processing is not limited to this.

  As a result, no matter what figure or curve the image is like “her” drawn in the lower left of FIG. 6, the contour region A1 is suitably extracted to make it depressed (dark), and the inside A three-dimensional expression with the embossed (bright) state and the outside background as a normal density can be realized through the OP layer.

  In the mode of embossing the image, when transferring the OP layer to the contour area A1, as shown in FIG. 9, the heat quantity is higher than the reference heat quantity when transferring the OP layer to the background area A3. When the OP layer is transferred to the image area A2 inside the contour area A1, the ink ribbon Pb is heated by changing the heat quantity to the lower heat quantity side than the reference heat quantity, but the image is depressed. 11 is selected, when transferring the OP layer to the contour area A1, as shown in FIG. 11, the heat quantity is changed to a higher heat quantity side than the reference heat quantity when the OP layer is transferred to the background area A3, or When forming the OP layer in the image area A2 inside the contour area A1, the ink ribbon Pb may be heated by changing the heat amount to a higher heat amount side than the reference heat amount. In the illustrated example, both the contour area A1 and the image area A2 are changed to the higher heat amount side. In this case, the contour area A1 is set to have a slightly higher heat amount than the image area A2, and the contour is blurred. I am trying not to. The amount of heat is gradually changed between the regions as described above.

  Of course, the combination of the amount of heat when transferring the OP layer to the contour region A1 and the amount of heat when transferring the OP layer to the image region A2 with respect to the reference heat amount when transferring the OP layer to the background region A3 May be other than the above.

  As described above, the printer according to the present embodiment transports the medium transport unit 5 that transports the printing medium Pa and the ink ribbon Pb that is a thermal transfer sheet on which an OP layer is formed on the image printed on the printing medium Pa. A ribbon transport unit 4 serving as a sheet transport unit, a thermal head 2 in which the heating elements 3 are arranged in a main scanning direction orthogonal to the transport direction of the printing medium Pa, a medium transport unit 5, the ribbon transport unit 4 and the thermal head 2. And a control means 1 for driving control. Then, the control means 1 heats the ink ribbon Pb with a reference heat amount when transferring the OP layer to the background area A3 outside the contour area A1 that draws the image based on the image data used for image printing. When the OP layer is transferred to the contour area A1, the ink ribbon Pb is heated by changing the heat amount to a lower heat amount or higher heat amount than the reference heat amount.

  For this reason, the higher the heating amount, the rougher the OP layer surface and the lower the light reflectance, resulting in a matte tone. The lower the heating amount, the better the OP layer surface and the higher the light reflectance. As a result, a glossy appearance is obtained. At this time, the matte tone seems to be depressed on the back side, and the glossy part appears to be raised on the near side. As described above, according to the present embodiment, it is possible to perform a three-dimensional representation of the image in a state where the outline is raised or depressed from the background by using the difference in calorific value without adding a separate mechanism. It can be expressed in a form that conforms to the image. Moreover, since it is not the heating control of the OP layer to the entire printing area but the heating control of the OP layer only in the area corresponding to the specific image, it is not necessary to secure a capacity for one piece of printing area data in the RAM 13. There is no heavy load.

  At the same time, when transferring the OP layer to the image area A2 inside the outline area A1, the control means 1 changes the heat amount to a lower heat amount or higher heat amount side than the reference heat amount and heats the ink ribbon Pb. Since this is done, it is possible to simultaneously perform a three-dimensional representation of the image in a state where the image is raised or depressed from the background, and that representation can also be performed in a manner according to the image. .

  Furthermore, since the heat amount data of the regions A2 and A3 adjacent to the contour region A1 are gradually changed from the contour region A1 toward the adjacent regions A2 and A3, the region A1-A2 and the region A1- It is possible to effectively avoid the formation of an unnatural boundary between A3.

  In particular, the control unit 1 of this embodiment is based on the image data acquisition unit 15 that acquires image data, the contour extraction unit 17a that extracts the contour region A1 from the acquired image data, and the region that is extracted by the contour extraction unit 17a. A heat quantity data generation unit 17b that generates heat quantity data for OP layer transfer, and the contour extraction unit 17a extracts both end positions of a region in which dot data corresponding to the pixels of the image data continues for a predetermined pixel or more as a contour region A1. Then, the heat quantity data generation unit 17b generates heat quantity data for each pixel for the inner image area A2 and the outer background area A3 based on the contour area A1, and drives and controls the thermal head 2 based on the heat quantity data. Since the image OP layer is transferred, even if the image data is arbitrarily given by a handwriting input tool or the like, There, the data for only the printing of the OP layer without affecting the color tone of the image can be appropriately generate.

  The specific configuration of each unit is not limited to the above-described embodiment. For example, when image data such as a stamp is prepared in advance in the printer, protective layer transfer data for applying a three-dimensional expression to the image data is prepared together with the image data, as shown in FIG. In addition, the image data acquisition unit 15 acquires the protection layer transfer data in which the heating amount is set for each pixel associated with the corresponding region as the image data is acquired, temporarily stores it in the RAM 13 or the like, and the control unit 1 However, the OP layer may be transferred by drivingly controlling the medium conveying means 5, the ribbon conveying means 4 and the thermal head 2 based on the OP heat quantity data.

  In this way, it is possible to instantaneously take out and use the calorific value data without frequently calculating each image that is frequently used.

  Further, the background image need not necessarily be all colored images. For example, when a photograph is taken and a character is overlapped and drawn using a pen tool or the like, only the character portion is used as the background image data, and the OP layer is transferred to the image data portion by applying the present invention. Calorie data generation may be performed.

  Furthermore, in the above embodiment, an example in which a relatively gentle heat quantity gradient as shown in FIG. 10 is applied from the contour region A1 to the image region A2 or the background region A3 is shown. You may make it give a calorie | heat amount difference. FIG. 13 shows an example of this. The contour area A1 has 200 gradations over 3 dots, and from there to the image area A2, the first 3 dots are reduced by 22 × 3 = 66 gradations, and then 3 It is connected to 100 gradations, which is the set heat amount of the image area A2 while lowering 5 gradations for each dot, and to the background area A3, the reference heat amount of the background area A3 (in this example, lowering 10 gradations for each dot). 150 gradation) is performed. In this way, the contour can be expressed more sharply.

  Other configurations can be variously modified without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 1 ... Control means 2 ... Thermal head 3 ... Heat generating element 4 ... Sheet conveyance means (ribbon conveyance means)
5 ... Medium conveying means 15 ... Image data acquisition means 17a ... Contour extraction section 17b ... Heat quantity data generation section A1 ... Contour area A2 ... Image area A3 ... Background area Pa ... Printing medium Pb ... Thermal transfer sheet (ink ribbon)

Claims (6)

Medium conveying means for conveying the printing medium;
Sheet conveying means for conveying a thermal transfer sheet on which a protective layer is formed for thermal transfer on an image printed on the printing medium;
A thermal head in which heating elements are arranged in a main scanning direction orthogonal to the conveyance direction of the printing medium;
In the medium transporting means, the sheet transporting means and a control means for driving and controlling the thermal head,
The control means, based on image data used for printing the image, heats the thermal transfer sheet with a reference heat amount when transferring the protective layer to a background region outside the contour region for drawing the image, and the contour region A printer configured to heat the thermal transfer sheet by changing the amount of heat to a lower heat amount or higher heat amount side than the reference heat amount when transferring the protective layer. Medium conveying means for conveying the printing medium;
Sheet conveying means for conveying a thermal transfer sheet on which a protective layer is formed for thermal transfer on the image formed on the printing medium;
A thermal head in which heating elements are arranged in a main scanning direction orthogonal to the conveyance direction of the printing medium;
In the medium transporting means, the sheet transporting means and a control means for driving and controlling the thermal head,
The control means, based on image data used for printing the image, heats the thermal transfer sheet with a reference heat amount when transferring the protective layer to a background region outside the contour region for drawing the image, and the contour region A printer configured to heat the thermal transfer sheet by changing a heat amount to a lower heat amount or a higher heat amount side than the reference heat amount when transferring a protective layer to an image area inside the printer.   The control unit further performs heating of the thermal transfer sheet by changing a heat amount to a lower heat amount or a higher heat amount side than the reference heat amount when transferring a protective layer to an image region inside the contour region. The printer described.   The printer according to any one of claims 1 to 3, wherein the calorific value data of an area adjacent to the contour area is gradually changed in heat amount from the contour area toward the adjacent area.   The control means generates image data acquisition means for acquiring image data, a contour extraction section for extracting a contour area from the acquired image data, and generates heat quantity data for transfer of the protective layer based on the area extracted by the contour extraction section. The contour extraction unit extracts, as the contour region, both end positions of a region in which dot data corresponding to the pixels are continuous from a predetermined pixel in the image data, and the heat amount data generation unit. 5 generates heat quantity data for each pixel in a predetermined area based on the outline area extracted by the outline extraction unit, and drives the thermal head based on the heat quantity data to heat the thermal transfer sheet. A printer according to any one of the above. The image data acquisition means acquires heat amount data for transfer of a protective layer for each pixel associated with the image data in a corresponding region as the image data is acquired, and the control means is based on the heat amount data. The printer according to any one of claims 1 to 5, wherein the thermal transfer sheet is heated by driving the thermal head.