JP2012048043A - Heater control device, printer, and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heater control device capable of highly accurately controlling the temperature of a heater in fixing a toner; and to provide a printer and a program.SOLUTION: A heater control unit includes: a deviation specification unit for specifying a deviation in a transfer amount of the toner at a prescribed area of a printing object; and a temperature control unit for controlling the temperature of the heater generating heat at a substantially uniform temperature for fixing to the printing object, the toner transferred to the prescribed area, according to the deviation specified by the deviation specification unit. The toner is transferred to the printing object so as to form an image represented by print image information, and the deviation specification unit specifies the deviation of the transfer amount of the toner at the prescribed area based on the print image information.

Description

  The present invention relates to a heater control apparatus, a printing apparatus, and a program for controlling the temperature of a heater for fixing toner to a printing material.

  Japanese Patent Application Laid-Open No. 2004-228561 calculates a toner covering amount according to the number of dots in a certain area of a print image, changes a heater temperature according to the toner covering amount, and changes a fixing roller temperature (fixing temperature). Technology is disclosed.

JP 2005-346074 A

  In the technique of Patent Document 1, the fixing temperature is changed in accordance with the toner coverage of the print image. Even if the toner coverage is the same, the content of the print image (image (character, figure, symbol, picture in the print image) Depending on the element, the shape of the photographic image, etc.), the color, etc.), the changed fixing temperature may not be suitable for fixing the toner (for example, the temperature is excessively higher than necessary). That is, with the technique of Patent Document 1, the temperature of the heater may not be accurately controlled in fixing the toner.

  The present invention has been made in view of such problems, and an object of the present invention is to provide a heater control device capable of accurately controlling the temperature of the heater in fixing the toner, To provide a printing apparatus and a program.

In order to achieve the above object, a heater control device according to the first aspect of the present invention provides:
A bias specifying means for specifying a bias in the transfer amount of toner in a predetermined area of the substrate;
Temperature control means for controlling the temperature of a heater for fixing the toner transferred to the predetermined area on the substrate according to the bias specified by the bias specifying means;
Is provided.

A printing apparatus according to a second aspect of the present invention is
The heater control device is provided.

A program according to the third aspect of the present invention is:
Computer
A bias specifying means for specifying a bias in the transfer amount of toner in a predetermined region of the substrate;
Temperature control means for controlling the temperature of a heater for fixing the toner transferred to the predetermined area on the substrate according to the bias specified by the bias specifying means;
To function as.

  According to the present invention, the temperature of the heater can be accurately controlled in fixing the toner.

1 is a configuration diagram of a printing apparatus according to an embodiment of the present invention. It is a figure which shows the structure of the printing apparatus of FIG. It is a figure for demonstrating the hardware constitutions of the heater control part of FIG. It is a block diagram for demonstrating the structure of the heater control part of FIG. 3 is a flowchart illustrating an example of heater control processing content performed by a heater control unit of the printing apparatus of FIG. 1. It is explanatory drawing for demonstrating the dot in a printing image. It is a figure which shows an example of the content of the data table referred in the heater control process of FIG. It is a figure for demonstrating an example of the relationship between a printed image and fixing temperature. It is a figure for demonstrating the dot pattern of a printing image. It is a figure which shows the relationship between the continuous frequency of the effective dot of a printed image, and a coupling rate. FIG. 6 is a diagram for explaining a relationship between a toner to be transferred / fixed on a sheet and a target temperature. FIG. 6 is a diagram for explaining a relationship between a toner to be transferred / fixed on a sheet and a target temperature.

  An embodiment according to the present invention will be described with reference to the drawings. In addition, this invention is not limited by the following embodiment (The content of drawing is also included). It goes without saying that changes (including deletion of components) can be added to the following embodiments. Moreover, in the following description, in order to make an understanding of this invention easy, description of a known technical matter is abbreviate | omitted suitably.

  As illustrated in FIG. 1, the printing apparatus 1 according to the present embodiment includes a controller unit 100 and a printing unit 200. In the following description, the direction in which the paper 3 is fed is referred to as the sub-scanning direction, and the direction orthogonal to the sub-scanning direction is referred to as the main scanning direction.

  The controller unit 100 controls the printing unit 200 to print a predetermined print image on the paper 3 (printed material). Details of the configuration and the like of the controller unit 100 will be described later. The print image is a picture, a text, a photograph, or the like.

  The printing unit 200 includes a photosensitive drum 201, a charging roller 202, an exposure device (exposure head) 203, a developing device 204, a transfer roller 205, a fixing unit 206, a cleaning device 207, an eraser light source 208, Is provided.

  The photosensitive drum 201 is charged to form an electrostatic latent image. The photosensitive drum 201 is driven by a driving unit (not shown) included in the printing unit 200 and rotates in the direction of the arrow about the axis. The photoconductor drum 201 is constituted by, for example, a negatively charged OPC (Organic Photo Conductor) photoconductor.

  The charging roller 202 uniformly charges the photosensitive drum 201. The charging roller 202 is, for example, a negative charger. A negative voltage is applied from a charging power source (not shown), and the peripheral surface of the photosensitive drum 201 is uniformly negatively charged and initialized.

  The exposure device 203 is a light emitting element array exposure device that performs optical writing (exposure) on the charged photosensitive drum 201, and forms an electrostatic latent image on the photosensitive drum 201 by optical writing. The exposure device 203 has a plurality of light sources (corresponding to dots to be described later) arranged in a line in the main scanning direction, and sequentially emits and emits light from each light source, thereby rotating the photosensitive drum 201. Exposure is sequentially performed for each dot row. As a result, an electrostatic latent image for one image is formed on the photosensitive drum 201.

  The developing device 204 includes a toner container 204a and a developing roller 204b. The toner storage unit 204a stores toner. The developing roller 204b rotates and conveys the toner stored in the toner storage unit 204a to the photosensitive drum 201 side. A developing bias is applied to the developing roller 204b from a developing bias power source (not shown). By this application, the toner accommodated in the toner accommodating portion 204a adheres to the rotating developing roller 204b, and the adhering toner is conveyed to the photosensitive drum 201 side. The toner conveyed by the developing roller 204b is transferred to the electrostatic latent image portion on the photosensitive drum 513. By this transfer, a toner image 240 of an image corresponding to the electrostatic latent image is formed on the photosensitive drum 201.

  The transfer roller 205 transfers the toner image 240 formed on the photosensitive drum 201 to the paper 3.

  The fixing unit 206 includes a fixing roller 206 a, a backup roller 206 b, a heater 206 c, and a thermistor 206 d, and thermally fixes the toner image 240 transferred to the paper 3 to the paper 3. The heater 206c is composed of a halogen lamp heater or the like, generates heat at a substantially uniform temperature, and heats the fixing roller 206a (heating target region) substantially uniformly. The thermistor 206d is used to measure the temperature of the fixing roller 206a. The sheet 3 is sandwiched between the fixing roller 206a and the backup roller 206b. Since the fixing roller 206 a is heated, the paper 3 sandwiched between the two is heated (by this, the toner of the toner image 240 is softened) and pressed, and the toner image 240 is thermally fixed to the paper 3.

  The cleaning device 207 removes the transfer leakage toner remaining on the photosensitive drum 201.

  The eraser light source 208 uniformly removes the surface of the photosensitive drum 201.

  The photosensitive drum 201 rotates and is charged by the charging roller 202. The exposure device 203 performs optical writing on the charged photosensitive drum 201 to form an electrostatic latent image on the photosensitive drum 201. The developing roller 204b adheres the toner accommodated in the toner accommodating portion 204a, and rotates and conveys the adhered toner to the photosensitive drum 201. As a result, the toner is transferred to the electrostatic latent image on the photosensitive drum 201, and a toner image 240 represented by the electrostatic latent image is formed. On the other hand, the paper 3 is transported by a transport belt or the like (not shown). The toner image 240 is transferred onto the sheet 3 by the transfer roller 205. The fixing roller 206a (heated by the heater 206c) and the backup roller 206b heat-fix the toner image 240 on the paper 3. The thermally fixed paper 3 is discharged out of the printing apparatus 1 by a predetermined discharge means. The cleaning device 207 removes the transfer leakage toner remaining on the photosensitive drum 201 after the toner image 240 is transferred. The eraser light source 208 uniformly removes the surface of the photosensitive drum 201 from which the transfer leakage toner has been removed.

  The configuration of the printing unit 200 is not limited to the above configuration, and the configuration can be changed as appropriate. For example, the transfer of the toner image 240 to the paper 3 may be performed using an intermediate transfer member or the like.

  As shown in FIG. 2, the controller unit 100 includes an I / F (interface) controller unit 110, a video I / F controller unit 120, an engine controller unit 130, and a heater control unit 140.

  The I / F controller unit 110 is connected to a host device 300 such as a personal computer (PC) 301 or a printer server 302 outside the printing apparatus 1. The I / F controller unit 110 and the PC 301 are connected via a Centronics interface, USB (Universal Serial Bus), etc., and the I / F controller unit 110 and the printer server 302 are connected via a LAN (Local Area Network). Has been. The I / F controller unit 110 and the PC 301 may be connected via a LAN.

  When printing is performed by an application such as a word processor, the PC 301 temporarily stores the print data in a print spooler (not shown) while converting the print data into command data. When the connection between the I / F controller unit 110 and the PC 301 is a Centronics interface or USB, command data is sent directly from the print spooler to the printing apparatus 1. When printing is performed via the printer server 302 connected via the LAN, the data stored in the print spooler of the PC 301 is transferred to the print spooler of the printer server 302, and the I / F controller unit is transferred from the print spooler in the printer server 302. Command data is sent to the printing apparatus 1 via 110.

  The I / F controller unit 110 includes a DSP (Digital Signal Processor), a memory, and the like. The memory functions as a buffer memory that sequentially and temporarily stores data generated by the DSP during processing. The DSP sequentially processes command data supplied from the host device, for example, extracts print data from the command data, performs expansion processing on the extracted print data, and print image data (for example, bitmap data) Video data) is generated and stored in the memory. When the DSP generates print image data for one page (stores print image data for one image in the memory), the DSP designates the start of printing to the engine controller unit 130 and print image data (/ VIDEO stored in the memory). [3: 0]) is supplied to the video I / F controller 120 in synchronization with a predetermined synchronization signal supplied from the engine controller 130.

  The synchronization signal is generated by the engine controller unit 130 (particularly, after the start of printing is specified). From the engine controller unit 130, the I / F controller unit 110 and the video I / F controller unit 120 are generated. The heater control unit 140 and the like are supplied. Examples of the synchronization signal include a horizontal synchronization signal (/ HSYNC), a vertical synchronization signal (/ VSYNC), and a synchronization clock (/ NVCLK). These synchronization signals are appropriately supplied to each unit, and each unit (engine controller unit 130, I / F controller unit 110, video I / F controller unit 120, heater control unit 140, etc.) operates in synchronization with these synchronization signals ( For example, supply data for each line or image). Thereby, each part synchronizes.

  The video I / F controller unit 120 includes a video DSP, a video memory, and the like. The video DSP receives print image data from the I / F controller unit 110 and records it in a video memory. Further, the video DSP sequentially transfers the print image data recorded in the video memory to the engine controller unit 130 for each line of the print image in accordance with a request from the engine controller unit 130.

  The engine controller unit 130 includes an ASIC (Application Specific Integrated Circuit) or the like. The engine controller unit 130 receives print image data for each image from the video I / F controller unit 120 for each line, operates the printing unit 200 based on a predetermined rule, and causes the sheet 3 to be printed. In particular, the engine controller unit 130 develops (acquires) the print image data into dot pattern data in which each pixel in the print image data is developed into N fine pixels (dots), and the developed dot pattern data Based on this, the exposure apparatus 203 is controlled to perform exposure.

  The dot pattern data is data representing a print image of the print image data by a pattern having dots as a minimum unit. The dot pattern data is data that specifies, for example, whether each dot is valid for each dot. Exposure is performed for dots that are valid (effective dots), and exposure is not performed for dots that are not valid (non-valid dots). In exposure, a high light signal is supplied to the light source that corresponds to the effective dots with respect to the rotating photosensitive drum 201, and a light source that corresponds to the ineffective dots is supplied to the light source that emits the light source. In order to make this light source non-light-emitting, a Low signal is supplied. Such supply of signals is performed under the control of the engine controller unit 130 and is continuously performed for one image. In this manner, an electrostatic latent image of an image represented by effective dots is formed on the photosensitive drum 201. Then, the toner is transferred onto the effective dot portion, that is, the electrostatic latent image in units of dots, and a toner image 240 represented by the electrostatic latent image is formed on the photosensitive drum 201. In the portion where the density of effective dots is high, the toner transfer amount is larger than in the portion where the effective dot is low.

  For example, as shown in FIG. 3, the heater control unit 140 includes a CPU (Central Processing Unit) 141, a ROM (Read Only Memory) 142, a RAM (Random Access Memory) 143, an I / O (In / Out) port 144, A D / A (digital / analog conversion) 145, an analog input 146, and an A / D (analog / digital conversion) 147 are provided. The heater control unit 140 is supplied with the dot pattern data from the engine controller unit 130 via the I / O port 144, and is supplied with a voltage value from the thermistor 206 d via the analog input 146. The voltage value is converted into digital data by the A / D 147 and supplied to the CPU 141. Further, the CPU 141 outputs a control signal to the D / A 145 according to the voltage value supplied from the thermistor 206d. The D / A 145 applies a voltage corresponding to the content of the control signal to the heater 206c. The CPU 141 controls the voltage applied to the heater 206c according to the voltage value supplied from the thermistor 206d (that is, the temperature of the fixing roller 206a), thereby controlling the temperature of the heater 206c. The RAM 143 functions as a main memory for the CPU 141. The ROM 142 stores programs, data (particularly, a table described later) and the like. The CPU 141 executes a heater control process (a process performed by the bias specifying unit 140a and the temperature control unit 140b) described later according to a program stored in the ROM 142 and using various data stored in the ROM 142.

  With the hardware configuration shown in FIG. 3, the heater control unit 140 includes a bias specifying unit 140a and a temperature control unit 140b as shown in FIG. The bias specifying unit 140a includes a CPU 141, a ROM 142, a RAM 143, and an I / O port 144, and the temperature control unit 140b includes a CPU 141, a ROM 142, a RAM 143, a D / A 145, an analog input 146, and an A / D 147.

  Here, a heater control process performed by the bias specifying unit 140a and the temperature control unit 140b will be described with reference to FIGS.

  This process starts when the dot pattern data is supplied from the engine controller 130.

  First, the bias specifying unit 140a acquires dot pattern data supplied from the engine controller 130 (step S101), and specifies the area ratio (%) of effective dots based on the acquired dot pattern data (step S102). . This area ratio can be obtained by the following formula 1, for example, where Z is the total number of dots in the dot pattern data (total number of dots: sum of effective dots and ineffective dots) and n is the number of effective dots. The bias specifying unit 140a specifies the number of effective dots and the total number of dots based on the dot pattern data, and calculates (specifies) the area ratio from the following formula 1 (in this embodiment, the decimal places are rounded off) To do.) Note that the bias specifying unit 140a may specify the area ratio by referring to a data table that includes the total number of dots and the number of effective dots and the area ratio, for example.

  Next, the bias specifying unit 140a specifies the bias in the entire print image of the effective dots based on the dot pattern data (step S103). This bias is represented by the coupling rate in the present embodiment. The coupling rate is calculated (specified) by the following mathematical formula 2 (in this embodiment liquid, the decimal point is rounded off). The bias specifying unit 140a calculates the coupling rate by the following formula 2 based on the dot pattern data (in this embodiment, the fractional part is rounded off).

  In the above formula, n is the number of effective dots. Xi is the number of effective dots constituting a predetermined dot group. This dot group is composed of one or more effective dots. When the dot group is composed of a plurality of effective dots, the dot group is composed of effective dots that are continuous in the vertical direction and / or the horizontal direction in the printed image. That is, when a dot group is composed of a plurality of effective dots, this dot group is a set of a plurality of effective dots in which other effective dots are located next to each other, and on a print image in units of dots, An unbroken island made up of effective dots is formed (see dot group 1 and dot group 2 in FIG. 6). In FIG. 6, some dots of the print image are drawn. In FIG. 6, the effective dot is “1” and the ineffective dot is “0”. Since the effective dots constituting the dot group 1 and the effective dots constituting the dot group 2 are interrupted on the way, these effective dots do not form one dot group. In the above equation, Xi = i. Yi is the number of the dot groups in the actual print image when Xi = i.

  As can be seen from the above equation, the coupling rate is a value that becomes 100 when all the effective dots constitute a dot group, and is a value that represents the ratio of the effective dots constituting the dot group. Of the total effective dots, the more effective dots that make up a dot group, and the more dot groups that contain many effective dots, the more effective dots are biased and the greater the coupling rate. Become. If the number of effective dots constituting the dot group is large and the number of dot groups including many effective dots is large, the effective dots are unevenly distributed in the entire print image. For this reason, the coupling rate represents the deviation of effective dots in the entire printed image. In addition, since a large amount of toner is transferred to a portion where there are many effective dots, the bias of the effective dots is also a bias of the transfer amount of toner in the entire print image to be printed.

  Note that the bias specifying unit 140a may specify the coupling rate by referring to a data table including the total number of dots and the number of effective dots and the coupling rate, for example.

  When the bias specifying unit 140a specifies the area ratio and bias of the effective dots, the temperature control unit 140b specifies a correction value for the fixing temperature based on the area ratio and bias of the effective dots specified by the bias specifying unit 140a ( Step S104). The correction value may be specified by calculating based on the area ratio and the deviation of the effective dots using a predetermined mathematical formula, but here, it is performed by referring to the data table.

  The data table stores data indicating the effective dot area ratio, effective dot bias, and correction value in association with each other, and the effective dot area ratio (1 to 100 percent). Each shows the correspondence between the effective dot bias and the correction value. FIG. 7 shows a part of the contents of this data table. FIG. 7 shows the relationship between the deviation of the effective dots and the correction value when the effective dots are 50%. Here, the correction value is a value used when setting a target temperature (target temperature of the fixing roller 206a) used when controlling the heater 206c. This correction value is appropriately determined by experiments or the like.

  The temperature control unit 140b sets a target temperature based on the correction value specified above (step S104). A reference base temperature (for example, 155 ° C.) is set in the temperature control unit 140b in advance (this data is recorded in, for example, the ROM 142 and used). The temperature control unit 140b adds the correction value to the base temperature, and sets the added value as a target temperature.

  As illustrated in FIG. 7, in the data table referred to in step S <b> 104, the correction value increases as the effective dot bias increases (when the coupling rate increases). For this reason, if a plurality of cases where the deviation of effective dots differs with the same area ratio is considered, the target temperature increases as the deviation of effective dots increases. For example, when the area ratio is 50% and the coupling ratio is 57%, the temperature control unit 140b specifies + 8 ° C. as the correction value and the specified correction at the base temperature (here, 155 ° C.). Add the values and set 163 ° C. as the target temperature. In the data table referred to in step S104, the correction value increases as the area ratio increases. For this reason, if a plurality of cases with the same coupling rate and different area rates are considered, the target temperature increases as the area rate increases.

  When the target temperature is set, the temperature control unit 140b controls the temperature of the heater 206c during the thermal fixing for one print image so that the temperature of the fixing roller 206a becomes the set target temperature (step S107). ), This process ends.

  The temperature controller 140b sequentially detects the temperature (fixing temperature) of the fixing roller 206a based on the voltage value supplied from the thermistor 206d so that the detected temperature of the fixing roller 206a becomes the target temperature set above. The temperature of the heater 206c is controlled. As described above, the temperature control unit 140b controls the heating temperature of the heater 206 by controlling the voltage applied to the heater 206c with a control signal. For example, if the temperature of the fixing roller 206a is lower than the target temperature, the temperature control unit 140b increases the voltage applied to the heater 206c to increase the temperature of the heater 206c. As a result, the temperature of the fixing roller 206a heated by the temperature of the heater 206c is raised. For example, if the temperature of the fixing roller 206a is higher than the target temperature, the temperature control unit 140b lowers the voltage applied to the heater 206c to lower the temperature of the heater 206c. As a result, the temperature of the fixing roller 206a heated by the temperature of the heater 206c is lowered.

  As shown in FIG. 8, when printing a first print image (combination rate: 0%) with an area ratio of 50% and a dot of 50% in which effective dots are dispersed, the target temperature is set to the base by the above processing. Heater control is performed such that the temperature is set to 155 ° C. and the fixing temperature is 155 ° C. In addition, when printing a solid second print image (combination rate: 100%) in which effective dots are concentrated in a predetermined area obtained by dividing the print image into two, the target temperature is the base temperature by the above processing. Heater control is performed such that the fixing temperature is set to 171 ° C. As described above, when the coupling rate is large, that is, when the deviation of effective dots is large, the target temperature is set high and the heater control is performed.

  Here, the present embodiment will be described based on further specific examples. Here, description will be made with reference to FIGS. Here, in order to facilitate understanding, a dot for one line in the printed image is considered. Further, the total number of dots for one line is 16 (the actual number of dots is larger). The effective dot is 8. That is, the area ratio of this one line is 50%. FIG. 9 illustrates some of the effective dot arrangement patterns in such a case. In FIG. 9, among 16 dots (see dot numbers 1 to 16 in FIG. 9 and the like), effective dots are indicated by black circles, and ineffective dots are indicated by white circles. For example, there are patterns 1 to 7 as the arrangement pattern of the effective dots when the area ratio is 50%. In pattern 1, eight effective dots are closer to the left side (dot numbers 1 to 8) of the 16 total dots. In FIG. 9, a plurality of continuous effective dots respectively constitute the dot group (for example, effective dots of dot numbers 1 to 8 in pattern 1).

  FIG. 10 shows the number of effective dots constituting the dot group (that is, continuous) and the number of dot groups having that number of effective dots for the patterns 1 to 7 in FIG. In FIG. 10, the numbers of the dot groups that are distinguished by the continuous number of effective dots (dot length) for each of the patterns 1 to 7 in FIG. 9 are collected. Further, the coupling rates for the patterns 1 to 7 are also summarized. The effective dot is also the number of light sources (exposure dots in FIG. 910) used for exposure. For example, in pattern 1, since there is only one dot group of eight consecutive effective dots, in FIG. 10, the number “1” is written in the column of “8” dot length, Since effective dots are combined (adjacent to other effective dots), the combination rate is 100%. For example, in pattern 1, since there is no dot group of two or more consecutive effective dots (that is, there are eight dots having one dot length), the “1” dot length column is The number “8” is described, and since all the effective dots are not combined (adjacent to other effective dots), the combination rate is 0%. As shown in FIGS. 9 and 10, even if the area ratio is the same, if the coupling ratio is different, it can be understood that the distribution of effective dots is different and the bias of effective dots is also different. If the coupling rate is high, the deviation of effective dots is large.

  Next, the relationship between the distribution of effective dots and the toner transferred and fixed on the paper 3 for the patterns 1 and 7 in FIG. 9 will be described with reference to the schematic diagrams of FIGS. FIG. 11 shows the relationship between the effective dot distribution for pattern 1 and the toner, and FIG. 12 shows the relationship between the effective dot distribution for pattern 7 and the toner. The exposure control in FIGS. 11 and 12 indicates that a High signal is supplied when a light source corresponding to a dot is caused to emit light. That is, the toner is transferred to the image for the dot corresponding to the light source to which the High signal is supplied.

  In FIG. 11, the effective dots are all continuous in the dot numbers 1 to 8. For this reason, the toner is gathered (biased) on the left side of the sheet 3 as viewed in the figure. The portion where the toner is collected becomes a lump as shown in FIG. In such a case, since the total amount of toner in one lump becomes large, heat conduction in the whole toner is deteriorated, and a high temperature is required to spread the heat necessary for softening (that is, fixing) to the whole toner. Become. That is, it is necessary to increase the target temperature.

  In FIG. 12, the effective dots are positioned at the dot numbers 1 to 16 in succession. For this reason, the toner is positioned in a discrete manner (dispersed). In this case, since the toner is dispersed, the toner does not become a large lump. In such a case, heat conduction in each toner is not particularly deteriorated, and a high temperature may not be required to spread the heat necessary for softening (that is, fixing) to the entire toner. That is, it is not necessary to increase the target temperature.

  As can be seen from the above, it is necessary to increase the target temperature as the effective dots are biased. When the effective dots are small, it is not necessary to increase the target temperature. However, since the heater temperature was controlled in accordance with the area ratio, there were cases where the fixing temperature was not appropriate (particularly when the fixing temperature was too low), such as when the deviation of the toner was large. In the above temperature control of the heater, even if the area ratio is the same, the target temperature is set higher (the temperature of the heater 206c is increased) as the toner transfer amount is biased (the coupling rate is higher). The target temperature is prevented from becoming unnecessarily too low or unnecessarily high. Even if the coupling rate is the same, if the area rate is different, the number of continuous effective dots is naturally different. In the above temperature control of the heater, even if the coupling rate is the same, if the area ratio is large, the target temperature is set high, so the target temperature is unnecessarily too low or unnecessarily high. Is prevented. As described above, in this embodiment, an appropriate target temperature is set.

  As described above, in the present embodiment, the bias specifying unit 140a performs the above-described processing so that the bias transfer unit 140a biases the toner transfer amount in a predetermined area of the paper 3 (in the present embodiment, the area where the entire print image is printed). In the embodiment, the effective dot is expressed based on the effective dot bias in the print image information (dot pattern data in the present embodiment). The toner is transferred to the paper 3 so as to form an image represented by the print image information. Further, the temperature control unit 140b controls the temperature of the heater 206b for fixing the toner transferred to the predetermined area on the paper 3 according to the bias specified by the bias special portion 140a. As a result, the target temperature, that is, the actual toner fixing temperature can be set to a temperature suitable for toner fixing as described above, and the temperature of the heater 206c can be accurately controlled during toner fixing. . In particular, it is possible to perform highly accurate control according to the characteristics of the print image. In the present embodiment, power saving is realized by controlling the temperature of the heater 206c with high accuracy to suppress unnecessary heating. Further, since the heating is not performed more than necessary, the curling of the paper 3 is prevented, the temperature rise of the printing apparatus 1 is suppressed, and the noise is reduced by reducing the rotation speed of the cooling fan in the printing apparatus 1. .

  The deviation in the toner transfer amount may be represented by, for example, the number of effective dots (the number of effective dots that are the most continuous) constituting a dot group that occupies the largest area in the entire print image. This is because if the target temperature is adjusted to fix such a dot group, even if other dot groups exist in the print image, the other dot groups are fixed on the sheet 3 by the target temperature. In this case, the target temperature increases as the number of effective dots increases. The bias specifying unit 140a specifies the number of the most effective dots that are continuous, and the temperature control unit 140b sets the target temperature based on this number in the same manner as described above.

  The predetermined area of the paper 3 is an area obtained by dividing an area for printing the entire print image in the main scanning direction of the image (the direction of one line in the print image) and / or the sub-scanning direction (a direction orthogonal to the main scanning direction). (Divided region) may be used. When the region divided in the sub-scanning direction is a predetermined region, for example, the bias specifying unit 140a specifies the bias of the toner transfer amount for each predetermined region, and the temperature control unit 140b determines the bias of each predetermined region. Based on the above, similarly to the above, temperature control (control of the temperature of the heater 206c) at the time of fixing and heating the toner is performed for each predetermined region. When the region divided in the main scanning direction is a predetermined region, a plurality of heaters (corresponding to the heater 206c) are arranged. For example, the bias specifying unit 140a specifies the bias of the toner transfer amount for each predetermined region. The temperature control unit 140b controls the temperature of each heater in the same manner as described above based on the bias of each predetermined region. By controlling the temperature of the heater in such a divided region, fine control of the heater is performed, and power saving and the like are further realized.

  In the above embodiment, the heater control unit 140 has been described as having a program stored in advance in a memory or the like. However, a program for executing the above processing is stored and distributed on a computer-readable recording medium such as a flexible disk, a CD-ROM (Compact Disc Read-Only Memory), a DVD (Digital Versatile Disk), and the like. May be installed in a computer to execute the above-described processing.

  Furthermore, the program may be stored in a disk device or the like included in a server device on the Internet, and the program may be downloaded to a computer (heater control unit 140), for example, superimposed on a carrier wave.

  The heater control unit 140 may be configured by at least a part of hardware (for example, an ASIC) that configures the engine controller unit 130. In this case, the engine controller unit 130 can also be regarded as a heater control device. In color printing, when fixing each color toner transferred to the paper 3 to one toner image composed of each color toner, it is desirable to apply the above-described embodiment to this one toner image.

DESCRIPTION OF SYMBOLS 1 ... Printing apparatus, 100 ... Controller part, 110 ... I / F controller part, 120 ... Video I / F controller part, 130 ... Engine controller part, 140 ... Heater control part , 140a... Bias identification unit, 140b... Temperature control unit, 200... Printing unit, 203... Exposure device, 206... Fixing unit, 206a.

Claims (6)

A bias specifying means for specifying a bias in the transfer amount of toner in a predetermined area of the substrate;
Temperature control means for controlling the temperature of a heater for fixing the toner transferred to the predetermined area on the substrate according to the bias specified by the bias specifying means;
A heater control device comprising: The heater generates heat at a substantially uniform temperature.
The heater control device according to claim 1. The toner is transferred to the substrate to form an image represented by print image information,
The bias specifying means specifies a bias of the toner transfer amount in the predetermined area based on the print image information.
The heater control device according to claim 1 or 2, wherein The temperature control means increases the temperature of the heater as the bias increases.
The heater control apparatus according to any one of claims 1 to 3, wherein   A printing apparatus provided with the heater control apparatus of any one of Claims 1 thru | or 4. Computer
A bias specifying means for specifying a bias in the transfer amount of toner in a predetermined region of the substrate;
Temperature control means for controlling the temperature of a heater for fixing the toner transferred to the predetermined area on the substrate according to the bias specified by the bias specifying means;
A program characterized by functioning as

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