JP3716982B2 - Image forming apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention records the ink applied to the surface layer by heating the recording medium on which the ink is applied to the surface layer using a print head that is driven and controlled by print data created from color image data. The present invention relates to an image forming apparatus for fixing and coloring a fixing layer of a medium.
[Prior art]
As a printing technique for applying a recording medium to a printing liquid such as ink to obtain a printed material, for example, a primary image is first formed on a thermal transfer sheet by an inkjet printer or the like, and then the thermal transfer sheet on which the image is formed is recorded on the recording sheet The image (ink) formed on the thermal transfer sheet is subjected to thermal sublimation transfer to the ink fixing layer of the thermal transfer sheet to form a secondary image on the thermal transfer sheet. A thermal transfer technique for obtaining a printed material is well known from JP-A-10-16188.
In JP-A-10-230589, a laminate material layer is provided in advance on an ink fixing layer of a recording sheet, an image is formed on the laminate material layer with an ink jet printer or the like, and then pressed through a heating roller. A heat fixing printing technique is disclosed in which a laminate material layer is made transparent by heating and an ink dye is fixed to a fixing layer to obtain a printed matter.
[0002]
[Problems to be solved by the invention]
In such an image forming apparatus, a sublimation ink is generally ejected onto a recording medium conveyed in the sub-scanning direction to form an image composed of ink droplets thereon, and then the ink is further added in a heat fixing step. By heating the droplets and fixing them on the fixing layer of the recording medium, a printed dot of a final image that is vividly colored is obtained.
[0003]
For this reason, the fixing color development property of the ink to the fixing layer in the heat fixing step is very important because it greatly affects the quality of the printed matter as the final product. In order to maintain a high level of reproducibility by maintaining this fixed color development characteristic, the specifications that greatly affect the fixation color development characteristic, such as the specifications of the recording medium itself and the heating device, must be maintained at a high level. I must. In other words, many types of recording media whose types of base materials are classified according to paper, film, etc. are handled, but the heat fixing characteristics in the fixing layer are constant regardless of the type of recording media. It must also be ensured that the heating and drying characteristics such as the heating temperature in the heating device are constant in any heating space region throughout the season.
[0004]
However, in order to satisfy such strict conditions, the recording medium and the heating device are forced to increase significantly in cost, and as a result, the marketability of the image forming apparatus becomes low.
SUMMARY OF THE INVENTION In view of the above circumstances, an object of the present invention is to provide an image forming apparatus provided with a technique that can compensate for variations in fixing color development characteristics caused by various factors by a simple method.
[0005]
[Means for Solving the Problems]
In order to solve the above problems, ink applied to a surface layer by heating a recording medium having the surface layer coated with ink using a print head driven and controlled by print data created from color image data. In the image forming apparatus for fixing and developing the color on the fixing layer of the recording medium, in the present invention, the heating device for heating the recording medium, and the fixing coloring property to the fixing layer of the ink obtained by heating the recording medium are used. Based on the color image data, a correction unit that performs correction for fixing color development characteristic compensation is provided, and the correction unit includes heating unevenness and / or drying unevenness that occurs during the heating process for the recording medium. The color image data is corrected in consideration of the variation in the fixing color development characteristic due to the above .
[0006]
In this configuration, the reason why the proper fixing color development characteristic cannot be finally obtained is not improved by seeking the recording medium or the heating device, but the fixing light emission characteristic, for example, an ink jet head or the like depending on a specific condition. When the density value of the print dot on the recording medium formed by the ink droplets from the print head fluctuates, this density is estimated and the density value of the color image data as the print source is compensated for the fluctuation. The adjustment is corrected. If the print dot density is insufficient due to the specifications of the recording medium or the heating device (variation from the appropriate value of the fixing light emission characteristic), it can be obtained as a result by correcting the density value of the color image data in advance. The density of the print dots is made appropriate (fixed light emission characteristics are appropriate). It is convenient that the correction ratios used for such correction of the fixed light emission characteristic compensation are obtained in advance through experiments, and various correction tables created based on these are selected each time during actual printing.
In particular, it is important to provide the correction unit with a function for correcting color image data in consideration of variations in fixing color development characteristics caused by heating unevenness and / or drying unevenness that occur during the heating process for the recording medium. is there. In a general heating device, particularly a heating device that sends heated air to heat the recording medium, the two-dimensional distribution of the temperature state and the dry state is not uniform. For this reason, heating unevenness and drying unevenness occur on the recording medium unique to the image forming apparatus, and the fixing color development characteristic deteriorates depending on the area. By preparing a correction table for the correction ratio of color image data necessary to bring such deterioration in fixing color characteristics in a specific area close to the ideal fixing color characteristics, a heating device is prepared. It is no longer necessary to request unrealistically high specifications.
[0007]
As one of the specific forms of the correction of the fixed light emission characteristic, a recording medium discriminating unit for discriminating the type of the recording medium is provided, and the fixing color development characteristic in the type of recording medium recognized by the recording medium discriminating unit It is proposed to give a correction unit a function of correcting color image data in consideration of the above. In this case, the fixing color development characteristic for every recording medium used in this image forming apparatus is experimentally obtained in advance, and the correction ratio of the color image data necessary to approximate this to the ideal fixing color development characteristic is calculated. Prepare a correction table for each recording medium so that it can be used selectively. Thereby, it is possible to omit a time-consuming configuration of changing the heating temperature and the heating time each time a recording medium having different fixing color development characteristics is loaded.
[0008]
As another specific form of the fixing light emission characteristic compensation correction, an environmental temperature detection unit that detects the environmental temperature of the image forming apparatus is provided, and the fixing coloring that occurs according to the environmental temperature recognized by the environmental temperature detection unit It is proposed to provide a correction unit with a function of correcting color image data in consideration of characteristic variation. Even in this case, it is necessary to install an image forming apparatus in advance under various environmental temperatures, experimentally determine the fixing color characteristics at various environmental temperatures, and approximate this to the ideal fixing color characteristics. The correction ratio of the color image data is prepared in a correction table so that it can be used selectively. As a result, constant fixing color development characteristics can be obtained throughout the four seasons or in any time period without adopting a costly configuration such as heat-insulating the main part of the image forming apparatus or installing a temperature control device. Is possible.
[0010]
When a certain sublimation ink suitable for the image forming apparatus according to the present invention is heated and sublimated and fixed on a fixing layer to develop a color, print dots forming a print image are distributed at a density of a predetermined level or more. However, since a relatively large amount of heat is required for ink sublimation, the desired density tends not to be achieved. In such a case, it is possible to calculate a fixed color development defective area of the print dot in the final print image, for example, a defective area related to density, from the color image data as the print source. Prepared so that the correction ratio of color image data necessary to bring the fixing color development characteristics of the area where fixing color development is expected to be close to the appropriate fixing color development characteristics into a correction table can be used selectively This also has a great advantage in some cases.
[0011]
As one of preferred embodiments of the present invention, a fixing color development characteristic compensation mode in which the correction unit corrects color image data as described above and a fixing color development characteristic no compensation mode in which this correction is not performed are selectively switched. Some have a mode selector. When a recording medium that does not require heat-fixing is selected, it is not necessary to compensate for fixing color development characteristics. For such a case, having a mode selection function for selecting a fixing color characteristic compensation mode and a fixing color characteristic non-compensation mode in which this correction is not performed increases the versatility of the image forming apparatus.
Other features and advantages of the present invention will become apparent from the following description of embodiments using the drawings.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
First, an example of a recording medium 1 handled by the image forming apparatus according to the present invention will be described with reference to FIG. In this recording medium 1, a fixing layer 11 for ink, that is, a dye is formed on a surface of a base material 10 made of a film sheet such as PET (polyethylene terephthalate) with urethane resin or the like, and the ink is further permeated thereon. A surface layer 12 is formed as a permeation layer. When the surface of the substrate 10 has a property capable of fixing the dye, the fixing layer 11 can be omitted. After an ink droplet is applied to the surface layer 12 of the recording medium 1 by an ink jet printer or the like to form an image, when the ink droplet is heated to an appropriate temperature, the applied ink droplet penetrates the surface layer and fixes the fixing layer 11. The dye is fixed. Furthermore, by peeling off the surface layer 12, a very glossy and vivid image-recorded sheet can be obtained as the final printed matter 100. In this recording medium 1, since it is necessary to finally peel off the surface layer 12 from the fixing layer 11 or the substrate 10, it is convenient to provide an easy-release agent between them.
[0013]
An example of an image forming apparatus for producing the final printed matter 100 using such a recording medium 1 will be described with reference to FIGS. As shown in FIG. 2, the image forming apparatus includes a print station PS and an operating station OS.
[0014]
The print station PS includes an inkjet print unit IU, a heat fixing unit HU mounted on the paper discharge side of the inkjet print unit IU, and a housing that covers these units.
[0015]
As is apparent from FIG. 3, in the print station PS, the surface layer 12 that is a print surface is formed by rewinding the recording medium 1 wound in a roll shape that can be stored in a roll sheet cartridge (not shown). The recording medium 1 is transported by the sheet transport mechanism 6 so as to come to the ink discharge port side of the ink jet head 2 as a print head. The inkjet head 2 is supported so as to be reciprocally movable by a head feeding mechanism 3 in a direction transverse to the conveyance direction of the recording medium 1, that is, in the main scanning direction, and ink is ejected from the ejection port to the surface layer 12 of the recording medium 1. Each time the ink-jet head 2 is moved in the main scanning direction while being ejected, the recording medium 1 is conveyed in the sub-scanning direction, whereby print images are sequentially formed. A plurality of discharge port modules capable of discharging different main colors to form a color print image are prepared in the inkjet head 2. For example, when a photographic quality color print image is required, in general, dark and light inks of the same color are used in addition to inks such as cyan, magenta, yellow, and black. Since the inkjet head 2 mounted on a general-purpose inkjet printer is used, further explanation is omitted here.
[0016]
The recording medium 1 on which the print image is formed on the surface layer 12 by the ink droplets 2a ejected from the ink-jet head 2 passes through the ink-jet print unit IU and creates a heat-fixing region where the ink is fixed to the fixing layer 11 by heat. To the heating and fixing unit HU. The heat fixing unit HU is provided with a heating device 4.
[0017]
In the recording medium 1 that has passed through the heat-fixed area, the ink (dye) forming the print image is fixed on the fixing layer 11 and has developed color. A final printed product 100 having an image is obtained. Although a series of conveyance of the recording medium 1 is performed by the conveyance mechanism 6 shown here by a roller method, other conveyance methods such as a belt method may be adopted.
[0018]
Since the recording medium 1 that is originally a long sheet needs to be cut according to the size of a print image formed thereon, a sheet cutter means 5 is provided. In this embodiment, the sheet cutter means 5 includes a first sheet cutter 5 </ b> A attached to the inkjet head 2 and a second sheet cutter 5 </ b> B provided in a rear region in the conveying direction of the heating device 4. The first sheet cutter 5A has the blade 51 attached to the ink jet head 2, so that the recording medium 1 can be cut by driving the head feed mechanism 3, whereas the second sheet cutter 5B has its blade. A dedicated feeding mechanism 53 for reciprocating the 52 is provided.
[0019]
Therefore, when a plurality of print images are continuously formed, the recording medium 1 is cut by the first sheet cutter 5A at the rear end of the entire length, and each print image unit is cut by the second sheet cutter. When a single print image is formed at 5B, the recording medium 1 is cut into a print image size by the first sheet cutter 5A and sent to the heating device 4.
[0020]
The heating device 4 includes an electric heater 41 for increasing the air temperature in the heating space, a temperature sensor 42 for measuring the temperature in the heating space, and an electric power inside the heating space formed by the wall 40 made of heat insulating material. A fan 43 that sends heated air heated by the heater 41, a fan motor 44 that drives the fan 43, and a shielding plate 45 that prevents the recording medium from being directly irradiated with heat from the electric heater 41 are provided. . By contacting the recording medium 1 with air heated to a predetermined temperature inside the heating space, non-contact heating is performed on the recording medium 1, and ink sublimation fixing is realized by this heating. In order for the recording medium 1 to pass through the heating space, the transport mechanism 6 is provided with a pressure-feed type transport roller unit composed of a driving roller and a driven roller at a position sandwiching the heating space.
[0021]
In this embodiment, the heating device 4 is configured to heat the recording medium 1 with heated air. Instead, an infrared heater (including a far-infrared heater) is disposed inside the heating space. Thus, the recording medium 1 can be heated by an infrared radiant heat beam.
[0022]
In the recording medium 1 described above, the sublimation ink used in this embodiment starts sublimation at about 80 ° C., and becomes an optimum sublimation fixing state by heating at 180 ° C. for about 2 minutes. This sublimable ink can be easily sublimated at a temperature of about 170 ° C. to 200 ° C., and the fixing layer 12 is required by heating for about 1 minute at 200 ° C. and heating for about 5 minutes at 170 ° C. The fixing coloring of the ink dye is realized.
[0023]
The inkjet head 2, the head feed mechanism 3, the heating device 4, the sheet cutter means 5, the transport mechanism 6, and the like are comprehensively controlled by a controller 7. In order to grasp the position of the recording medium 1 conveyed by the conveyance mechanism 6, a sheet detection sensor 60 is installed at a predetermined position on the conveyance line formed by the conveyance mechanism 6, and the detection signal is also sent to the controller 7. Further, a recording medium type detection sensor 61 for detecting an ID code applied to the roll sheet cartridge or the shaft body that winds and supports the recording medium 1 is also installed to send the detection signal to the controller 7. The controller 7 can specify the specifications such as the fixing color development characteristic of the recording medium 1 loaded from the detection signal.
[0024]
The controller 7 of the image forming apparatus includes a first controller 7A on the operating station OS side and a second controller 7B on the print station PS side, and is connected to each other via a communication cable so that data can be exchanged. It can function like
[0025]
As shown in FIG. 2, the operating station OS includes a general-purpose computer 80 that also functions as the first controller 7A, a monitor 81, a keyboard 82, a mouse 83, and a developed silver salt film F. Film scanner 85 that photoelectrically converts images into color image data, and data holding media (CD, CD-R, or MO, and communication that consists of data communication lines as well as semiconductor media such as compact flash and smart media) And an image acquisition unit 84 (which is built in the computer 80 in this case) for extracting color image data from the medium. In this image forming apparatus, the color image data transferred to the first controller 7A through the film scanner 85 and the image acquisition unit 84 is sent to the second controller 7B as print data after being subjected to various data processing and printed. A print image is formed on the recording medium 1 at the station PS.
[0026]
The controller 7 includes a first controller 7A and a second controller 7B, each having a microcomputer system including a CPU, a ROM, a RAM, an I / O interface circuit, and the like as core members. As shown in FIG. In the first controller 7A, peripheral devices such as an image acquisition unit 84 and a film scanner 85 for sending image data are connected via an I / O interface circuit. In the second controller 7B, a peripheral device such as an image acquisition unit 84 is connected via an I / O interface circuit. Peripheral devices incorporated in the print station PS such as the inkjet head 2, the head feeding mechanism 3, the heating device 4, and the transport mechanism 6 are connected. The first controller 7A and the second controller 7B can transmit data via their respective communication modules, and the image data that has undergone image processing and correction processing in the first controller 7A is substantially the final print data. After being converted and transmitted to the second controller 7B via the communication modules 74a and 74b, it is used for applying sublimation ink to the recording medium 1.
[0027]
Each function by the controller 7 is created by hardware and / or software. However, here, if only the functional elements related to the present invention are listed, a print designated through the operation of the keyboard 82 and the mouse 83 by the operator will be described. A print size setting unit 70 for setting an image size, and an image processing unit 72 for performing resolution change or trimming on the image data transferred from the image data input unit 9 based on the print image size set by the print size setting unit 70 In addition to general image correction processing such as color correction and head shading correction, a correction unit 90 for performing correction processing for fixing color development characteristics described later, which characterizes the present invention, and a correction table used in the correction unit 90 91, the correction table storage unit 92 for storing 91 A correction mode selection unit 93 for designating the correction table 91 and loading the correction table 91 from the correction table storage unit 92 to the correction unit 90, and using a binarization method such as error diffusion from the corrected image data. A print data generation unit 73 that generates print data for the head 2, a print control unit 75 that drives the inkjet head 2 based on the transferred print data and discharges ink droplets from the ejection ports, and driving the inkjet head 2. At the same time, the head feed control unit 76 that moves the inkjet head 2 in the main scanning direction, intermittently feeds the recording medium 1 and feeds the recording medium 1 to the heating device 4 every time the inkjet head 2 moves in the main scanning direction. Based on detection signals from the conveyance control unit 77 and the temperature sensor 42, the heating device 4, a heating control unit 78 that drives and controls the infrared heater 41, and a recording medium type determination unit that acquires information such as the width of the recording medium 1 loaded from the ID code read by the recording medium type detection sensor 61. 79a, an environmental temperature detection unit 79b that detects the environmental temperature of the image forming apparatus based on a signal from the temperature sensor 86, and a fixing coloring defect area calculation that calculates a region where fixing coloring defects can occur from color image data as a print source. The part 79c and the like are representative.
[0028]
In addition to the color correction processing normally performed in digital photographic prints, the correction unit 90 performs fixing color development characteristic compensation correction to compensate for deterioration in fixing light emission characteristics caused by specific conditions. For example, when the density value of a print dot on a recording medium formed by ink droplets from a print head such as an ink jet head fluctuates, a color image as a print source is estimated to compensate for the fluctuation by estimating this fluctuation. The density value of the data is adjusted and corrected. If the print dot density is insufficient due to the specifications of the recording medium or the heating device, the density of the color image data is corrected in advance. Appropriate). The correction table 91 used for such correction of the fixed light emission characteristic compensation is created through an experiment in advance for each condition affecting the fixing color development characteristic, stored in the correction table storage unit 92, and selected as a correction mode as required. The data is selected by the unit 93 and loaded into the correction unit 90. When such a correction table 91 for fixing color characteristic compensation is loaded into the correction unit 90, the correction unit 90 functions as a fixing color characteristic compensation correction unit.
[0029]
Since generally used correction tables for image processing such as color correction and sharpness are well known, only the correction table 91 for compensating the color development characteristics will be described here.
Due to individual differences in the image forming apparatus, particularly the heating device 4, the state of the heating space also varies, and as a result, the hue of the finally obtained print image may deviate from an appropriate one to some extent. For this reason, a print test is performed in advance using test print pattern image data, and the print image obtained thereby is compared with an ideal image prepared in advance, and correction for color image data necessary to compensate for the difference is performed. The ratio is obtained, and a correction table 91 for fixing color development characteristic compensation is created. This is a basic correction table 91 relating to compensation for fixing color development characteristics.
[0030]
The fixing color development characteristics of the recording medium 1 itself often vary slightly if the manufacturer is different or the size is different even if the manufacturer is the same. For this reason, test printing is performed for each type of recording medium 1, and a correction table 1 for fixing color development characteristic compensation for each recording medium corresponding to a specific type of recording medium 1 is created and stored in the correction table storage unit 92. The correction mode selection unit 93 loads the appropriate correction table 1 into the correction unit 90 based on the recording medium type determined by the recording medium type determination unit 79a.
[0031]
Moreover, even if the difference between individual differences of the heating device 4 can be compensated, the heating behavior of such a heating device 4 has a great influence on the environmental temperature unless it is arranged in a large heat insulating space. For this reason, test printing is performed for each predetermined environmental temperature, and a fixing color characteristic compensation correction table 91 for each environmental temperature corresponding to a specific type of recording medium 1 is created and stored in the correction table storage unit 92. The correction mode selection unit 93 may load the appropriate correction table 1 into the correction unit 90 based on the environmental temperature determined by the environmental temperature detection unit 79b.
[0032]
Furthermore, there are cases where it is necessary to take into account variations in fixing color development characteristics caused by heating unevenness and / or drying unevenness that occur during the heating process for the recording medium 1. Since such heating unevenness or drying unevenness depends on a partial area of the recording medium 1 to be heated and dried, uniform correction cannot be performed. In order to compensate for such a problem, an area where heating unevenness or drying unevenness is generated is checked in advance by a test print or the like, and a correction table 91 for fixing coloring characteristic compensation with masking is created outside the area. There is a need to. That is, when the dot density value of the print image is low only in a predetermined area due to heating unevenness or drying unevenness, correction is performed to increase only the density value of color image data corresponding to that area.
[0033]
In addition, when sublimation ink is heated and sublimated to fix the color on the fixing layer, the water contained in the ink will evaporate, but this moisture evaporation takes a certain amount of heat, resulting in printing. There is a tendency that a desired density is not achieved in an area where dots are distributed at a density of a predetermined level or higher. In order to compensate for such a problem, an image data area in which print dots are distributed at a density of a predetermined level or higher is regarded as a fixing coloring defect area, and the density value of pixels belonging to the area is finally set to an appropriate value. A correction table 91 for correcting the color development characteristic for correcting the color development characteristic is prepared in advance. Such a fixed color defect region can be recognized by a fixed color defect region recognition unit 79c that can be constructed by a programming method known in the image processing technology.
[0034]
Ideally, it is desirable to use all of the fixing color characteristic compensation table 91 as described above. Of course, only these arbitrary ones may be used. When a normal inkjet recording paper that does not need to be heat-fixed is used as the recording medium 1, the correction of the fixing color characteristic is omitted by the correction mode selection unit 93 that can be operated by the operator using the keyboard 82 or the like. Is done.
[0035]
Next, how a captured image is formed on the recording medium 1 using color image data of the captured image read from the color negative film F using the film scanner 85 will be described with reference to a schematic flowchart of FIG.
[0036]
When the color negative film F is read by the film scanner 85, the CCD output signal of the film scanner 85 is amplified and AD converted and transferred to the image data input unit 71 as 12-bit RGB color image data (# 01). The color image data is subjected to typical correction as scanner data such as gamma correction in the image data input unit 71 and then sent to the image processing unit 72 (# 02). Before and after this, the operator operates the keyboard 82 and the mouse 83 while looking at the print order slip, designates and inputs the print image size, and sets the print image size in the print size setting unit 70 (# 03).
[0037]
The image processing unit 72 performs resolution conversion corresponding to the finished print size based on the print image size received from the print size setting unit 70 for the received color image data and trimming as necessary. At the same time, the 12-bit data is converted into 8-bit data and delivered to the correction unit 90 (# 05).
[0038]
In addition to the color correction processing normally performed in digital photographic prints, the correction unit 90 performs correction for the above-described fixing color development characteristic compensation. First, a basic correction table 91 relating to fixing color development characteristic compensation is loaded from the correction table storage unit 92 to the correction unit 90 (# 07) by address designation by the correction mode selection unit 93 (# 07). Done. Further, the fixing color development characteristic compensation correction corresponding to the type of the recording medium 1 is obtained from the recording medium type determination unit 79a (# 08). The correction mode selection unit 93 selects an appropriate correction table based on the recording medium type information. This is done by loading 1 into the correction unit 90. Similarly, the fixing color development characteristic compensation correction according to the environmental temperature is obtained from the environmental temperature detection unit 79b (# 09). Based on the environmental temperature information, the correction mode selection unit 93 loads the appropriate correction table 1 into the correction unit 90. Is done. In addition, if the correction table 1 taking into account the variation of the fixing color development characteristics due to heating unevenness and / or drying unevenness is stored in the correction table storage unit 92, this is also loaded into the correction unit 90, and the heating unevenness and drying Correction to compensate for unevenness is performed.
[0039]
Further, when the fixed color defect region is recognized by the fixed color defect region recognition unit 79c from the color image data as the print source, this fixed color defect region information is sent to the correction mode selection unit 93 (# 10). Based on this, the correction mode selection unit 93 loads the appropriate correction table 1 masked by the fixing color development defective area information into the correction unit 90. It should be noted that the function of the fixing color defect area recognition unit 79c is incorporated in the correction table 1, and correction is performed in a filter process such that when a predetermined density value is distributed at a predetermined density, the density value is adjusted. A configuration may be adopted.
[0040]
When all necessary color image data correction is completed in the correction unit 90, the color image data is sent to the print data generation unit 73 (# 11). Since the RGB color image data is converted into CMYK color image data at an appropriate stage before and after other corrections in the correction unit 90, the color image data sent to the print data generation unit 73 is CMYK color image data.
[0041]
The print data generation unit 73 performs binarization processing for performing gradation formation by area gradation by the inkjet head 2 from the received 8-bit CMYK color image data, and generates binary CMYK print data, and the print control unit 75 (# 12).
[0042]
The print control unit 75 generates a drive pulse signal for the inkjet head 2 from the transferred binary CMYK print data, thereby controlling the drive element of the inkjet head 2 and spraying ink droplets onto the recording medium 1. . At the same time, the head feed control unit 75 drives and controls the head feed mechanism 3, and the carry control mechanism 77 drives and controls the carry mechanism, whereby a photographic image is formed on the recording medium 1 (# 13).
[0043]
The recording medium 1 on which the photographed image is formed is heated and fixed by passing through the heating space of the heating device 4 whose temperature is adjusted by the heating control unit 78 with the set heating temperature as the control target temperature (# 14). By performing appropriate fixing color development characteristic compensation correction, a final printed matter 100 having a desired color tone is finally obtained.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view illustrating an example of a recording medium handled by an image forming apparatus according to the present invention. FIG. 2 is an external view illustrating an embodiment of an image forming apparatus according to the present invention. FIG. 4 is a functional block diagram for explaining the function of the controller. FIG. 5 is a diagram illustrating how the input image data is corrected and then sent to the inkjet head as print data. Schematic flow diagram showing how it is formed 【Explanation of symbols】
DESCRIPTION OF SYMBOLS 1 Recording medium 2 Inkjet head 3 Head feed mechanism 4 Heating device 6 Conveyance mechanism 7 Controller 7A 1st controller 7B 2nd controller 72 Image processing part 73 Print data generation part 75 Print control part 79a Recording medium type determination part 79c Fixing color development Defect area recognition unit 79b Environmental temperature detection unit 86 Temperature sensor 90 Correction unit (fixing color development characteristic compensation correction unit)
91 Correction Table (Fixing Coloring Characteristic Compensation Correction Table)
92 Correction table storage unit 93 Correction mode selection unit

Claims (5)

Using a print head that is driven and controlled by print data created from color image data, the recording medium with the ink applied to the surface layer is heated to cause the ink applied to the surface layer to be fixed to the recording medium. In an image forming apparatus for fixing and developing color,
A heating device for heating the recording medium, and a fixing color characteristic compensation correction when creating print data from the color image data based on the fixing color characteristic of the ink obtained by heating the recording medium to the fixing layer. A correction unit that performs correction, and the correction unit corrects color image data in consideration of variations in fixing color development characteristics caused by heating unevenness and / or drying unevenness that occur during the heating process for the recording medium. An image forming apparatus.   A recording medium discriminating unit for discriminating the type of the recording medium is provided, and the correction unit takes into account the color development characteristics of the recording medium of the type recognized by the recording medium discriminating unit in consideration of the color development characteristics. The image forming apparatus according to claim 1, wherein the image data is corrected.   An environmental temperature detection unit for detecting the environmental temperature of the image forming apparatus is provided, and the correction unit takes into account the variation of the fixing color development characteristic that occurs according to the environmental temperature recognized by the environmental temperature detection unit. The image forming apparatus according to claim 1, wherein the image data is corrected. Optimal fixing color defect region out of the fixing coloring characteristics are calculated from the color image data, according to claim 1 to 3 wherein the correction unit, characterized in that for correcting the color image data corresponding to the calculated fixed color defect regions The image forming apparatus according to any one of the above. 2. A mode selection unit that selectively switches between a fixed color development characteristic compensation mode in which color image data is corrected by the correction unit and a fixed color development characteristic non-compensation mode in which this correction is not performed is provided. The image forming apparatus according to any one of 1 to 4 .

Images