JP2021173829A - Image forming apparatus and program - Google Patents

Abstract

To stabilize fixing quality without increasing the number of temperature detection sensors.SOLUTION: An image forming apparatus 1 comprises: an image forming unit 17 that forms an image on a sheet P; a fixing unit 18 that has a heating unit that can change the amount of heating and fixes the image formed on the sheet to the sheet through application of heat and pressure performed by a heating roller; an image measuring unit of an image measuring device 300 that measures the feature quantity of the image on the sheet P after the fixing and outputs the measured value of the feature quantity; and a control unit that controls the amount of heating performed by the heating roller based on the measured value of the feature quantity measured by the image measuring unit.SELECTED DRAWING: Figure 1

Description

The present invention relates to an image forming apparatus and a program.

Conventionally, there is known an image forming apparatus that forms a toner image on paper and fixes the toner image on the paper by heating and pressurizing a fixing member. In the image forming apparatus, since cooling fans for cooling are installed in various places in the image forming apparatus, various air flows may give an inclination to the temperature distribution in the axial direction of the fixing member.

Therefore, one end and the other end of the heater unit so that the temperature in the axial direction of the heater unit as the fixing member becomes uniform according to the operating status of a plurality of airflow generating members such as an in-machine cooling fan. An image forming apparatus for controlling the heating amount of the above is known (see Patent Document 1).

Japanese Unexamined Patent Publication No. 2016-206296

However, in the image forming apparatus described in Patent Document 1, even if the operating status of a plurality of airflow generating members is acquired, the state changes depending on the outside air temperature, paper passing, paper passing history, and the like. It is very difficult to completely assume the amount of control. Further, although it is possible to make the temperature distribution uniform by increasing the number of temperature detection sensors, it is very difficult to arrange a large number of temperature detection sensors including a safety device.

An object of the present invention is to stabilize the fixing quality without increasing the number of temperature detection sensors.

In order to solve the above problems, the image forming apparatus of the invention according to claim 1 is used.
An image forming part that forms an image on paper,
A fixing portion having a heating portion in which the amount of heating can be changed, and fixing an image on the image-formed paper by heating and pressurizing by the heating portion, and a fixing portion.
An image measuring unit that measures the feature amount of the image on the paper after fixing and outputs the measured value of the feature amount, and the image measuring unit.
A control unit for controlling the heating amount of the heating unit is provided based on the measured value of the feature amount by the image measuring unit.

The invention according to claim 2 is the image forming apparatus according to claim 1.
The image measuring unit has an optical sensor and outputs a measured value of an image feature amount based on the detected amount detected by the sensor.

The invention according to claim 3 is the image forming apparatus according to claim 2.
The sensor irradiates the image on the paper with irradiation light, detects the amount of reflected light, and determines the amount of reflected light.
The image measuring unit outputs the glossiness of the image corresponding to the amount of the detected reflected light as a measured value.

The invention according to claim 4 is the image forming apparatus according to claim 2.
The sensor detects the pixel value of the image on the paper and
The image measuring unit outputs the color of the image corresponding to the detected pixel value as a measured value.

The invention according to claim 5 is the image forming apparatus according to any one of claims 1 to 4.
The control unit compares the measured value of the feature amount measured by the image measurement unit with the preset reference value of the feature amount, and controls the heating amount of the heating unit based on the comparison result. ..

The invention according to claim 6 is the image forming apparatus according to claim 5.
The reference value is set for each paper information.

The invention according to claim 7 is the image forming apparatus according to claim 6.
The control unit calculates the paper information from the measurement result of the position where there is no image on the paper by the image measuring unit.

The invention according to claim 8 is the image forming apparatus according to any one of claims 1 to 7.
The image measuring unit measures the feature amounts of a plurality of image regions located in the direction perpendicular to the paper passing direction of the paper, and measures the features.
The control unit controls the amount of heating in the axial direction of the heating unit based on the measured values of the measured feature amounts of the plurality of image regions.

The invention according to claim 9 is the image forming apparatus according to claim 8.
The heating unit can control the heat generation distribution along the axial direction perpendicular to the paper passing direction.

The invention according to claim 10 is the image forming apparatus according to claim 9.
The heating unit has a plurality of divided heating units that are arranged along the axial direction and each of which can independently control the heating amount.

The invention according to claim 11 is the image forming apparatus according to claim 9.
The heating unit has a plurality of heat distribution heating units having different heat distributions in the axial direction.

The invention according to claim 12 is the image forming apparatus according to any one of claims 8 to 11.
The control unit controls the amount of heating in the axial direction of the heating unit based on the difference between the measured values of the measured features of the plurality of regions.

The invention according to claim 13 is the image forming apparatus according to any one of claims 1 to 12.
The image forming portion forms a patch outside the normal image area of the paper.
The image measuring unit measures the feature amount of the patch.

The invention according to claim 14 is the image forming apparatus according to any one of claims 1 to 13.
The image measuring unit measures the feature amount of the image measuring area in the normal image area of the paper.

The invention according to claim 15 is the image forming apparatus according to claim 1.
The image measuring unit
An image load applying portion that applies a load to the image surface of the paper,
The first sensor that measures the feature amount of the image before applying the load, and
It has a second sensor that measures the feature amount of the image after the load is applied, and based on the measured value of the first sensor and the measured value of the second sensor, the paper Output the measured value of the adhesion strength of the image,
The control unit controls the heating amount of the heating unit based on the measured value of the adhesion strength.

The invention according to claim 16 is the image forming apparatus according to claim 15.
The image load applying unit is
It has a contact portion that comes into contact with the image surface of the paper.

The invention according to claim 17 is the image forming apparatus according to claim 16.
The contact portion is a non-woven fabric, an elastic body or a tape.

The invention according to claim 18 is the image forming apparatus according to claim 15.
The image load applying portion is a fine particle spraying portion that sprays fine particles onto the image surface of the paper.

The invention according to claim 19 is the image forming apparatus according to claim 18.
The image load applying unit has a collecting unit that collects the sprayed fine particles by air flow.

The program of the invention according to claim 20
Computer,
It has a heating part whose heating amount can be changed, and the image is fixed on the paper image-formed by the image forming part by heating and pressurizing by the heating part. Features of the image of the paper after being fixed by the fixing part. A control unit that controls the heating amount of the heating unit based on the measured value of the feature amount measured by the image measuring unit that measures the amount and outputs the measured value of the feature amount.
To function as.

According to the present invention, the fixing quality can be stabilized without increasing the number of temperature detection sensors.

It is a schematic block diagram of the image forming apparatus of the 1st Embodiment of this invention. It is a side view of the fixing part. (A) is a top transmission view of the heating roller. (B) is a diagram showing the amount of heat generated with respect to the axial position of the heating roller. (A) is a top transmission view of a heating roller of another example. (B) is a figure which shows the calorific value with respect to the position in the axial direction of the heating roller of another example. It is a block diagram which shows the functional structure of an image forming apparatus. It is a figure which shows the 1st image measurement pattern. It is a figure which shows the 2nd image measurement pattern. It is a figure which shows the reference glossiness with respect to the image density of a paper. It is a figure which shows the reference glossiness with respect to the image density for each paper type. It is a figure which shows the fixing temperature with respect to the image density. It is a flowchart which shows the 1st heating amount control process. It is a flowchart which shows the 2nd heating amount control processing. It is a figure which shows the schematic structure of the image measuring apparatus of 2nd Embodiment. It is a side view which shows the image load applying part of the 2nd Embodiment. It is a figure which shows the heating amount with respect to the adhesion strength. It is a side view of the image measuring apparatus of the 2nd modification. It is a side view in the main scanning direction of the image load application part of the 2nd modification.

The first embodiment, the first modification, the second embodiment, and the second modification according to the present invention will be described in detail in order with reference to the accompanying drawings. The present invention is not limited to the illustrated examples.

(First Embodiment)
The first embodiment according to the present invention will be described with reference to FIGS. 1 to 11. First, the apparatus configuration of the present embodiment will be described with reference to FIGS. 1 to 10. FIG. 1 is a schematic configuration diagram of the image forming apparatus 1 of the present embodiment.

The image forming apparatus 1 of the present embodiment is a multifunction device (MFP (MultiFunction Peripheral)) that forms a color image on paper by an electrophotographic method based on image data received from an external device. The image forming apparatus 1 may be another electrophotographic type image forming apparatus such as a printer.

As shown in FIG. 1, the image forming apparatus 1 includes a paper feeding device 200, an image forming apparatus main body 100, an image measuring apparatus 300, and rear along a paper flow (paper passing direction) from upstream to downstream. A processing device 400 and a paper ejection tray T4 are provided in this order. The image forming apparatus main body 100 forms a color toner image on the paper supplied from the paper feeding unit 20 (described later) based on the image data received from the external device, fixes it by heating and pressurizing, and forms a subsequent image. The paper after image formation is conveyed to the measuring device 300.

The paper feed device 200 includes a large-capacity paper feed tray (not shown), acquires paper from the paper feed tray instructed by the control unit 11 (described later) of the image forming device main body 100, and transfers the paper to the image forming device main body 100. Transport.

The image measuring device 300 measures the glossiness of the image-formed paper conveyed from the image forming apparatus main body 100, and conveys the image forming apparatus main body 100 to the post-processing apparatus 400 in the subsequent stage.

The post-processing device 400 includes a post-processing unit 22 (not shown in FIG. 1) for performing post-processing on the paper. Examples of the post-treatment include a staple treatment, a punch hole punching treatment, a folding treatment, and a bookbinding treatment. The post-processing device 400 performs post-treatment on the image-formed paper conveyed from the image measuring device 300 by the post-processing unit 22 as necessary, and ejects the post-treated or untreated paper. Discharge to paper tray T4.

The output tray T4 is a tray on which the image-formed (, post-processed) paper conveyed from the post-processing device 400 is placed.

As shown in FIG. 1, the image forming apparatus main body 100 includes an operation unit 12, a display unit 13, an image forming unit 17, a fixing unit 18, paper feed trays T1 to T3, a transport unit 19, and the like.

The operation unit 12 has a touch panel formed so as to cover the display screen of the display unit 13, and various operation buttons such as a number button and a start button.

The display unit 13 is composed of display panels such as an LCD (Liquid Crystal Display) and an EL (ElectroLuminescence) display, and displays various display information on the display screen of the display panel.

The image forming unit 17 forms an image on the paper supplied from the paper feeding unit 20. The image forming unit 17 is an image forming unit 17Y, 17M, 17C, 17K for each color of yellow (Y), magenta (M), cyan (C), and black (K), an intermediate transfer belt 177, and a secondary transfer roller 178. And so on. Each image forming unit 17Y, 17M, 17C, 17K has a photoconductor drum 171, a charging unit 172, an exposure unit 173, a developing unit 174, a primary transfer roller 175, and a cleaning unit 176.

Here, each part of the yellow image forming unit 17Y will be described. The photoconductor drum 171 is a rotating body on which a yellow toner image is formed. The charging unit 172 uniformly charges the photoconductor drum 171. The exposure unit 173 scans and exposes the surface of the photoconductor drum 171 with a beam such as a laser beam based on the yellow component of the image data related to the image formation to form an electrostatic latent image. The developing unit 174 stores the yellow toner and attaches the yellow toner to the electrostatic latent image on the photoconductor drum 171 to perform development. The primary transfer roller 175 transfers the yellow toner image formed on the photoconductor drum 171 onto the intermediate transfer belt 177 (primary transfer). The cleaning unit 176 removes the toner remaining on the photoconductor drum 171. The magenta, cyan, and black image forming units 17M, 17C, and 17K are the same as the yellow image forming units 17Y, except that the colors (toners) handled are different.

The intermediate transfer belt 177 is an endless belt on which toner images formed on the photoconductor drums 171 of each color of the image forming units 17Y, 17M, 17C, and 17K are sequentially transferred. The secondary transfer roller 178 transfers the four-color toner image formed on the intermediate transfer belt 177 onto the paper (secondary transfer).

The fixing section 18 conveys the paper on which the toner image is formed by the image forming section 17, and fixes the toner image on the paper by heating and pressurizing.

The paper feed unit 20 has paper feed trays T1, T2, T3, a paper feed roller, and the like, and supplies paper to the image forming unit 17. Paper of a predetermined paper type and size is stored in each of the paper feed trays T1 to T3. The paper feed unit 20 includes the paper feed device 200.

The transport unit 19 is composed of a transport roller, a resist roller, and the like for transporting paper, and is on a paper transport path from the paper feed unit 20 to the image measuring device 300 via the image forming unit 17 and the fixing unit 18. It is arranged and transports the paper on the paper transport path. Further, the transport unit 19 includes an inversion section that reverses the paper that has been image-formed by the image forming section 17 and is conveyed from the fixing section 18 and conveys the paper to the image forming section 17 again. Further, the transport unit 19 is assumed to include a paper transport unit on the paper transport path that is transported from the image forming apparatus main body 100 and reaches the paper output tray T4 via the image measuring device 300 and the post-processing device 400.

The image forming apparatus 1 may be configured to include other parts such as a scanner that reads a document and generates image data.

Here, the configuration of the fixing portion 18 will be described with reference to FIGS. 2 to 4. FIG. 2 is a side view of the fixing portion 18. FIG. 3A is a top transmission view of the heating roller 182. FIG. 3B is a diagram showing the amount of heat generated with respect to the axial position of the heating roller 182. FIG. 4A is a top transmission view of another heating roller 182a. FIG. 4B is a diagram showing the amount of heat generated with respect to the axial position of the heating roller 182a of another example.

As shown in FIG. 2, the fixing portion 18 includes a fixing roller 181, a heating roller 182 as a heating portion, a fixing belt 183, a pressure roller 184, and a motor 185. The fixing roller 181 is a roller whose axial direction is arranged in a direction perpendicular to the paper passing direction (paper conveying direction). The heating roller 182 is a roller that is arranged in the axial direction in the direction perpendicular to the paper passing direction, has a heating source inside, and is heated by the heating source.

In FIGS. 3A to 4B, the back side of the image forming apparatus 1 of FIG. 1 is on the left side, and the front side of the image forming apparatus 1 of FIG. 1 is on the right side. As shown in FIG. 3A, the heating roller 182 has a plurality of heater portions 1821 as divided heating portions which are heating sources extending in the axial direction from the back side of the device to the front side of the device. The number of heater portions 1821 is, for example, five, but is not limited to, the left end portion, the left middle portion, the center portion, the right middle portion, and the right end portion. As shown in FIG. 3B, each heater unit 1821 individually and independently generates heat within a variable width range in response to a change in the target temperature on the surface of the heating roller 182 or a change in the input electric power. It is controllable. Here, the power input to each heater unit 1821 is changed by duty control or waveform thinning control.

Further, the heating roller 182 may be configured to replace the heating roller 182a as another example shown in FIG. 4A. The heating roller 182a has a central heat distribution heater 1822 as a heat distribution heating unit and end heat distribution heaters 1823 and 1824. The central heat distribution heater 1822 is a heater portion that heats the central portion in the axial direction from the back side of the device to the front side of the device and does not heat both ends. The end heat distribution heater 1823 is a heater portion in which the heating amount at the right end portion in the axial direction between the back side of the device and the front side of the device is larger than the heating amount at the left end portion and does not heat the central portion. The end heat distribution heater 1824 is a heater portion in which the heating amount at the left end portion in the axial direction between the back side of the device and the front side of the device is larger than the heating amount at the right end portion and does not heat the central portion. In FIG. 4B, the amount of heat generated by the central heat distribution heater 1822 is shown by a solid line, and the amount of heat generated by the end heat distribution heater 1823 is shown by a dotted chain line in the axial direction from the back side of the device to the front side of the device. The amount of heat generated by the partial heat distribution heater 1824 is shown by a broken line.

Returning to FIG. 2, the fixing belt 183 is an endless belt hung on the fixing roller 181 and the heating roller 182, and transfers the heat of the heating roller 182 to the fixing roller 181. The pressure roller 184 is a roller whose axial direction is arranged in a direction perpendicular to the paper transport direction and is pressed against the fixing roller 181 to form a nip portion. The motor 185 is a motor that rotates the pressure roller 184 around the axis. The rotation of the pressurizing roller 184 by the motor 185 also rotates the fixing roller 181 and the heating roller 182. The paper passed through the nipb is heated and pressurized by the fixing roller 181 and the pressure roller 184.

Then, with reference to FIG. 5, the internal functional configuration of the image forming apparatus 1 will be described. FIG. 5 is a block diagram showing a functional configuration of the image forming apparatus 1.

As shown in FIG. 5, the image forming apparatus 1 includes a control unit 11, an operation unit 12, a display unit 13, a storage unit 14, a communication unit 15, an image processing unit 16, and an image forming unit 17. It includes a fixing unit 18, a transport unit 19, a paper feeding unit 20, an image measuring unit 21, and a post-processing unit 22. Each part of FIG. 5 of the image forming apparatus 1 is connected via a bus 23.

The control unit 11 is composed of a CPU (Central Processing Unit), a RAM (Random Access Memory), a ROM (Read only Memory), and the like, and controls each unit of the image forming apparatus 1. The control unit 11 reads various programs stored in the ROM, expands them in the RAM, and executes various processes in cooperation with the expanded programs and the CPU. For example, it is assumed that the ROM of the control unit 11 stores a first heating amount adjusting program for executing the first heating amount adjusting process described later.

The operation unit 12 receives a touch input and a button press input from the user, and outputs the operation information to the control unit 11.

The display unit 13 displays the display information on the display panel according to the display information input from the control unit 11.

The storage unit 14 is composed of a non-volatile storage device such as an HDD (Hard Disk Drive), an SSD (Solid State Drive), or a flash memory, and stores various data such as image data.

The communication unit 15 transmits / receives data to / from an external device such as a PC (Personal Computer) connected via a communication network such as a LAN (Local Area Network). The control unit 11 transmits / receives data to / from an external device via the communication unit 15. For example, the communication unit 15 receives a job including image data for printing from an external device.

The image processing unit 16 has, for example, a rasterization processing unit, a color conversion unit, a gradation correction unit, and a halftone processing unit. Various image processing is performed on the received image data for printing (stored in the storage unit 14).

Under the control of the control unit 11, the image forming unit 17 receives image data from an external device via the communication unit 15 (image processed by the image processing unit 16), and then image-processed paper feed based on the image data for printing. An image is formed on the paper fed from the unit 20.

According to the control of the control unit 11, the fixing unit 18 heats and pressurizes the paper on which the toner image is formed by the image forming unit 17 to fix the toner image on the paper.

The image measuring unit 21 measures the glossiness as a feature amount of the image surface of the paper conveyed from the image forming apparatus main body 100 in which the toner image is fixed by the fixing unit 18 under the control of the control unit 11, and the measured glossiness is measured. Is output to the control unit 11. As shown in FIG. 1, the image measuring unit 21 includes a sensor 31 provided on a paper transport path in the image measuring device 300. The sensor 31 is an optical type that irradiates the surface of the paper P transported in the paper transport direction (conveyance direction, sub-scanning direction) on the paper transport path in the image measuring device 300 with light and detects the amount of the reflected light. It is a sensor, for example, a line sensor extending in the main scanning direction perpendicular to the paper passing direction. The glossiness as a feature amount indicating the fixed state of the image on the paper is the value [%] of the measured light amount of the reflected light with respect to the light amount of the irradiation light. The image measuring unit 21 calculates the glossiness corresponding to the amount of reflected light measured by the sensor 31 and outputs it to the control unit 11. Toner (image) TN is formed and fixed on the paper P to be measured.

The post-processing unit 22 performs various post-processing as necessary on the image-formed and fixed image-formed paper conveyed from the image measuring device 300 under the control of the control unit 11, and the image-measured paper is appropriately subjected to various post-processing, and the output tray T4 Discharge to.

Here, the measurement of the glossiness of the image measuring unit 21 and the fixing temperature of the fixing unit 18 will be described with reference to FIGS. 6 to 10. FIG. 6 is a diagram showing a first image measurement pattern. FIG. 7 is a diagram showing a second image measurement pattern. FIG. 8 is a diagram showing a reference glossiness with respect to the image density of the paper. FIG. 9 is a diagram showing a reference glossiness with respect to an image density for each paper type. FIG. 10
Is a diagram showing the fixing temperature with respect to the image density.

As shown in FIG. 6, the image measuring unit 21 is, for example, a normal image area (printing) formed in the image measuring areas AR10 and AR20 at both ends in a direction perpendicular to the paper passing direction (main scanning direction) of the paper P. The glossiness of the patch (patch image) pb, pg, pr as an image measurement pattern outside the main image area) is measured. The patch pb is a solid blue rectangular image. The patch pg is a solid green rectangular image. The patch pr is a solid red rectangular image. The patches of the same color in the image measurement areas AR10 and AR20 are respectively located on the direction (main scanning direction) perpendicular to the paper passing direction of the paper P, and the positions in the paper passing direction are the same. When the paper P is cut and used, the toner patches pb, pg, and pr are formed by the image forming unit 17 outside the normal image area (image measurement areas AR10 and AR20), and the images are patched by the image measuring unit 21. The state of the image is obtained by reading the glossiness of the images of pb, pg, and pr. The position of the patch on the paper P is not limited to both ends in the main scanning direction, and may be, for example, the ends in the paper passing direction.

Further, as shown in FIG. 7, the image measuring unit 21 may be configured to measure the glossiness of the patch as the image measuring pattern formed in the image measuring regions AR1 and AR2 in the normal image of the paper P. .. The image measurement areas AR1 and AR2 are located on the direction (main scanning direction) perpendicular to the paper passing direction of the paper P, and the positions in the paper passing direction are the same. When the paper P is not cut, a toner patch cannot be formed outside the normal image area. Therefore, the image measuring unit 21 measures the glossiness of the images in the image measuring areas AR1 and AR2 in the normal image area. At that time, since the measurement result differs depending on the image density, the control unit 11 acquires the image density information from the image data of the normal image region used for the image forming unit 17. Further, the control unit 11 determines the development conditions of the image forming unit 17 (such as the charging potential of the charging unit 172 and the development bias applied between the photoconductor drum 171 and the developing unit 174) and the transfer conditions (to the secondary transfer roller 178). A more accurate image density can be obtained by considering the transfer current value to be passed, etc.).

FIG. 8 shows the reference glossiness of the image measurement areas AR1 and AR2 with respect to the image density of the image measurement areas AR1 and AR2 of the paper of FIG. 7. From the graph of FIG. 8, a predetermined reference glossiness is uniquely determined with respect to a predetermined image density. In addition, the reference glossiness changes depending on the image density. Therefore, the control unit 11 calculates the reference glossiness corresponding to the image density, and determines the fixing state by comparing the reference glossiness with the measurement result of the glossiness of the image measurement unit 21. In the example of FIG. 7 using the images of the image measurement areas AR1 and AR2 in the normal image area, the density of the measurement portion (images of the image measurement areas AR1 and AR2) differs depending on the output image, so that the image data of each area Use the standard glossiness corresponding to the image density calculated based on.

FIG. 9 shows the reference glossiness of the image measurement area AR1 with respect to the image density for each paper type. In FIG. 9, the reference glossiness of plain paper having a relatively low glossiness of the paper is shown by a solid line, and the reference glossiness of a cross-coated paper having a relatively high glossiness of the paper is shown by a broken line. The standard glossiness for the same image density may differ depending on the paper type. Therefore, the control unit 11 calculates the reference glossiness in consideration of the paper type information.

FIG. 10 shows the fixing temperature with respect to the image density of the paper. As shown in FIG. 10, when the image density in the actual measurement region is higher than the target image density, it can be considered that the fixing temperature is high. Therefore, the control unit 11 heats the fixing unit 18 so that the fixing temperature is calculated based on the difference between the target image density and the image density corresponding to the glossiness measured by the image measuring unit 21. Is calculated.

Then, the operation of the image forming apparatus 1 will be described with reference to FIG. FIG. 11 is a flowchart showing the first heating amount control process.

Here, among the operations of the image forming apparatus 1, the control of the fixing temperature in the image forming of the image forming apparatus 1 will be described. In advance, in the image forming apparatus 1, a printing job is input from an external device via the communication unit 15, and the control unit 11 sets the paper feeding unit 20, the image forming unit 17, and the fixing according to the input printing job. The image data of the job is formed and fixed on the paper, including fixing by the default fixing temperature by the unit 18 and the conveying unit 19, and the image forming and the glossiness of the paper after fixing are measured by the image measuring unit 21, if necessary. The post-processing by the post-processing unit 22 is started accordingly.

In the image forming apparatus 1, it is triggered that a printing job is input from an external device via the communication unit 15 in parallel with image forming, fixing, image measurement, and post-processing on paper based on the above printing job. As a result, the control unit 11 executes the first heating amount control process according to the first heating amount control program stored in the ROM. The first heat amount control process is executed for each fixing of one sheet of paper until the printing of the job is completed, and the same applies to the second heat amount control process described later.

As shown in FIG. 1, the control unit 11 determines the paper type as the paper information of the input printing job, and the image to be measured in the image data of the job (for example, the image measurement areas AR10 and AR20 in FIG. 6). The image density of the patch pb, pg, pr of the above, or the image of the image measurement areas AR1 and AR2 of FIG. 7) is acquired, and the reference glossiness is calculated from the acquired paper type and image density (step S10). In step S10, for example, the relationship of the reference glossiness with respect to the image density for each paper type of FIG. 9 is stored in advance in the storage unit 14 with data such as a LUT (Look Up Table), and the control unit 11 stores the LUT. Data such as the above is read from the storage unit 14, and the reference glossiness of the paper is calculated by using the read data, the acquired paper type, and the image density. Further, in step S10, the control unit 11 shall acquire the paper type based on the glossiness of the region other than the image of the paper P measured by the image measuring unit 21. However, the present invention is not limited to this, and when the printing job includes paper information (paper type), the control unit 11 may be configured to acquire the paper type from this job.

Further, in step S10, in the present embodiment, for example, it is assumed that the reference glossiness corresponding to the average value of the glossiness measured in each of the image measurement areas AR1 and AR2 is calculated. For example, in the image measurement pattern of FIG. 6, the reference glossiness corresponding to the average value of the image densities of the patches pb, pg, and pr of the image measurement areas AR10 and AR20 is calculated. In the image measurement pattern of FIG. 7, the reference glossiness corresponding to the average value of the reference glossiness of the image densities of the images in the image measurement areas AR1 and AR2 is calculated.

Then, the control unit 11 acquires the measured glossiness from the glossiness of the images in the image measurement areas AR1 and AR2 of the paper measured by the image measurement unit 21 (step S11). In the present embodiment, for example, it is assumed that the average value of the glossiness measured in each of the image measurement areas AR1 and AR2 is used as the measurement glossiness. For example, in the image measurement pattern of FIG. 6, the average value of the glossiness measured in the patches pb, pg, and pr of the image measurement areas AR1 and AR2 is calculated as the measurement glossiness. In the image measurement pattern of FIG. 7, the average value of the glossiness measured in each of the images in the image measurement areas AR1 and AR2 is calculated as the measurement glossiness. Then, the control unit 11 compares the measured glossiness acquired in step S11 with the reference glossiness calculated in step S10 (step S12).

When the measured glossiness> the reference glossiness (step S12;>), the control unit 11 reduces the heating amount of the fixing temperature of the fixing unit 18, and controls the fixing temperature of the fixing unit 18 with the reduced heating amount (step). S13), the first heating amount control process is completed. In step S13, for example, the relationship of the fixing temperature with respect to the difference in glossiness (measured glossiness-reference glossiness) for each paper type corresponding to the fixing temperature corresponding to the image density in FIG. 10 is stored in data such as LUT. It is stored in the unit 14 in advance, and the control unit 11 reads the data such as the LUT from the storage unit 14, and calculates the amount of heating to be reduced by using the read data and the difference in glossiness. For example, as shown in FIG. 10, when the reference glossiness corresponds to the target image density and the measured glossiness corresponds to the measured value of the image density, the heating for shifting from the measured value of the fixing temperature to the target fixing temperature. The amount of decrease corresponds to the amount of deviation corresponding to the arrow on the figure. The control unit 11 changes the target temperature for switching ON / OFF of the heating roller 182 (or 182a) as a heating source according to the calculated decrease in the heating amount, or changes the lighting duty of the duty control of the fixing unit 18. Or change the waveform thinning control. Specifically, when reducing the heating amount in step S13, the target temperature is lowered, the lighting duty is reduced, or the thinning amount of the lighting waveform is increased.

When the measured glossiness = the reference glossiness (step S12; =), the control unit 11 does not change the heating amount of the fixing temperature of the fixing unit 18, and controls the fixing temperature of the fixing unit 18 with the same heating amount (step S12; =). Step S14), the first heating amount control process is completed. When the measured glossiness <reference glossiness (step S12; <), the control unit 11 increases the heating amount of the fixing temperature of the fixing unit 18, and controls the fixing temperature of the fixing unit 18 with the increased heating amount (step). S15), the first heating amount control process is completed. In step S15, the control unit 11 increases the heating amount so as to heat from the measured fixing temperature to the target fixing temperature in the same manner as in the calculation of the decrease amount of the heating amount and the control of the fixing unit 18 in step S13. And control the fixing unit 18. Specifically, when increasing the heating amount in step S15, the target temperature is increased, the lighting duty is increased, or the thinning amount of the lighting waveform is decreased.

As described above, according to the present embodiment, the image forming apparatus 1 has an image forming unit 17 for forming an image on paper and a heating roller 182 whose heating amount can be changed, and by heating and pressurizing by the heating roller 182. , The fixing unit 18 for fixing the image on the image-formed paper, the image measuring unit 21 for measuring the feature amount of the image on the paper after fixing, and outputting the measured value of the feature amount, and the feature by the image measuring unit 21. A control unit for controlling the heating amount of the heating roller 182 based on the measured value of the amount is provided. Therefore, the fixing quality of the image on the paper can be stabilized so that the feature amount of the image on the paper after fixing is the same without increasing the temperature detection sensor in the image forming apparatus 1.

Further, the image measuring unit 21 has a sensor 31 and outputs a measured value based on the detected amount detected by the sensor 31. More specifically, the sensor 31 irradiates the image of the paper with irradiation light and detects the amount of the reflected light. The image measuring unit 21 outputs the glossiness as the feature amount of the image corresponding to the light amount of the irradiation light and the detected light amount of the reflected light as the measured value. Therefore, the quality of the fixing glossiness of the image on the paper can be stabilized.

Further, the control unit 11 compares the measured glossiness measured by the image measuring unit 21 with the reference glossiness as a preset reference value, and based on the comparison result, heats the heating roller 182. Control. Therefore, the fixing quality can be stabilized so that the fixing glossiness of the image on the paper matches the target reference glossiness.

The standard glossiness is set for each paper type as paper information. Therefore, the fixing quality can be more stable depending on the paper type.

Further, the control unit 11 calculates the paper type from the measurement result of the position where there is no image on the paper by the image measurement unit 21. Therefore, even if the job does not have paper information, the paper type can be easily acquired.

Further, the image forming unit 17 forms patches pb, pg, pr in the image measurement areas AR10 and AR20 outside the normal image area of the paper as shown in FIG. The image measuring unit 21 measures the glossiness of the patches pb, pg, and pr. Therefore, the glossiness can be accurately measured by the patches pb, pg, and pr that do not affect the image formation in the normal image region.

Further, the image measuring unit 21 measures the glossiness of the image of the image measuring areas AR1 and AR2 in the normal image area of the paper as shown in FIG. Therefore, the fixing quality of the image of the element can be stabilized without cutting the paper.

(First modification)
A first modification as a modification of the first embodiment will be described with reference to FIG. FIG. 12 is a flowchart showing a second heating amount control process.

The device configuration of this modification uses the image forming device 1 as in the first embodiment. However, it is assumed that the ROM of the control unit 11 stores a second heating amount control program for executing the second heating amount control process described later in place of the first heating amount control program. ..

Next, the operation of this modification in the image forming apparatus 1 will be described with reference to FIG. In advance, in the image forming apparatus 1, a printing job is input from an external device via the communication unit 15, and the control unit 11 sets the paper feeding unit 20, the image forming unit 17, and the fixing according to the input printing job. The image data of the job, including fixing at the default fixing temperature by the unit 18 and the conveying unit 19, is formed on the paper, and the image measuring unit 21 forms the image and measures the glossiness of the paper after fixing, if necessary. The post-processing by the post-processing unit 22 is started. Further, in this modification, the paper is image-formed by the image measurement pattern of FIG. 6, and the glossiness measurement area is the patches pb, pg, pr of the image measurement areas AR10 and AR20 of FIG.

In the image forming apparatus 1, it is triggered that a printing job is input from an external device via the communication unit 15 in parallel with image forming, fixing, image measurement, and post-processing on paper based on the above printing job. As a result, the control unit 11 executes the second heating amount control process according to the second heating amount control program stored in the control unit 11.

As shown in FIG. 12, first, the control unit 11 acquires the glossiness of the images of the image measurement areas AR10 and AR20 of the paper measured by the image measurement unit 21 (step S21). The measured glossiness of the image measurement area AR10 (or AR20) is, for example, the average value of the measurement glossiness of the patches pb, pg, pr of the image measurement area AR10 (or AR20). Then, the control unit 11 compares the measured glossiness of the image measurement areas AR10 and AR20 measured in step S21 (step S22).

When the measurement glossiness of the image measurement area AR10> the measurement glossiness of the image measurement area AR20 (step S22;>), the control unit 11 is on the image measurement area AR10 side with respect to the fixing temperature on the image measurement area AR20 side of the fixing unit 18. The heating ratio of the fixing temperature is reduced, the fixing temperature of the fixing portion 18 is controlled by the reduced heating ratio (step S23), and the second heating amount control process is completed. In step S23, for example, when the fixing unit 18 has the heating roller 182, the control unit 11 reduces the heating amount of the heater unit 1821 on the image measurement region AR10 side (the back side of the image forming apparatus 1 in FIG. 1). Alternatively, the heating amount of the heater unit 1821 on the image measurement area AR20 side (front side of the image forming apparatus 1 in FIG. 1) is increased, or the heating amount of the heater unit 1821 on the image measurement area AR10 side is decreased and the image measurement is performed. The heating amount of the heater unit 1821 on the region AR20 side is increased, and the heater unit 1821 is controlled according to these heating amounts. The control by increasing or decreasing the heating amount of the heater unit 1821 is performed, for example, by adjusting the lighting duty of the duty control or controlling the thinning amount of the lighting waveform of the waveform thinning control, as in the first embodiment.

In step S23, for example, when the fixing unit 18 has the heating roller 182a, the control unit 11 is an end heat distribution heater having a large amount of heat on the image measurement region AR10 side (the back side of the image forming apparatus 1 in FIG. 1). The amount of heat of 1824 is decreased, or the amount of heat of the end heat distribution heater 1823, which is large on the image measurement area AR20 side (front side of the image forming apparatus 1 in FIG. 1), is increased, or the amount of heat is increased. The heating amount of the heat heater 1824 is decreased and the heating amount of the end heat distribution heater 1823 is increased, and the heating roller 182a including the end heat distribution heaters 1824 and 1823 is controlled according to these heating amounts.

When the measurement glossiness of the image measurement area AR10 = the measurement glossiness of the image measurement area AR20 (step S22; =), the control unit 11 is on the image measurement area AR10 side with respect to the fixing temperature on the image measurement area AR20 side of the fixing unit 18. The fixing temperature of the fixing portion 18 is controlled at the same heating ratio without changing the heating ratio of the fixing temperature (step S24), and the second heating amount control process is completed.

When the measurement glossiness of the image measurement area AR10 <the measurement glossiness of the image measurement area AR20 (step S22; <), the control unit 11 is on the image measurement area AR10 side with respect to the fixing temperature on the image measurement area AR20 side of the fixing unit 18. The heating ratio of the fixing temperature is increased, the fixing temperature of the fixing portion 18 is controlled by the increased heating ratio (step S25), and the second heating amount control process is completed. In step S25, for example, when the fixing unit 18 has the heating roller 182, the control unit 11 increases the heating amount of the heater unit 1821 on the image measurement region AR10 side (the back side of the image forming apparatus 1 in FIG. 1). Alternatively, the heating amount of the heater unit 1821 on the image measurement area AR20 side (front side of the image forming apparatus 1 in FIG. 1) is decreased, or the heating amount of the heater unit 1821 on the image measurement area AR10 side is increased and the image measurement is performed. The heating amount of the heater unit 1821 on the region AR20 side is reduced, and the heater unit 1821 is controlled according to these heating amounts.

In step S25, for example, when the fixing unit 18 has the heating roller 182a, the control unit 11 is an end heat distribution heater having a large amount of heat on the image measurement region AR10 side (the back side of the image forming apparatus 1 in FIG. 1). Increase the amount of heat of 1824, or decrease the amount of heat of the end heat distribution heater 1823, which has a large amount of heat on the image measurement area AR20 side (front side of the image forming apparatus 1 in FIG. 1), or end arrangement. The heating amount of the heat heater 1824 is increased and the heating amount of the end heat distribution heater 1823 is decreased, and the end heat distribution heaters 1824 and 1823 are controlled according to these heating amounts.

When the fixing portion 18 has the heating roller 182, the measurement glossiness of the image measurement area AR10 and the reference glossiness of the plurality of measurement positions (image measurement areas AR10 and AR20) are compared and the image measurement area AR10 is compared. The heating amount of the heater unit 1821 on the side was obtained, and the heating amount of the heater unit 1821 corresponding to the measured glossiness of the other image measurement area AR20 was obtained by comparing with the measured glossiness on the image measurement area AR10 side. It can also be the amount of heating of. The image measurement area AR10 and the image measurement area AR20 may be reversed. Further, when the fixing portion 18 has the heating roller 182a, the heating amount on the image measurement areas AR10 and AR20 is controlled in the same manner as when the fixing portion 18 has the heating roller 182.

Further, when the paper is formed with the image measurement pattern of FIG. 7, and the images of the image measurement areas AR1 and AR2 as the glossiness measurement areas are formed with the same image density, the image is formed. The second heating control process can be applied to the measurement areas AR10 and AR20 → the image measurement areas AR1 and AR2.

As described above, according to the present modification, the image measuring unit 21 measures the gloss amount as the feature amount of the images of the image measuring areas AR10 and AR20 located in the direction perpendicular to the paper passing direction (main scanning direction). The control unit 11 controls the heating amount in the axial direction of the heating roller 182 based on the measured gloss amount of the measured image measurement areas AR10 and AR20. Therefore, the fixing quality of the image on the paper in the axial direction (main scanning direction) can be stabilized.

Further, the heating roller 182 can control the heat generation distribution along the axial direction perpendicular to the paper passing direction. More specifically, it has a plurality of heater units 1821 that are arranged along the axial direction and can independently control the amount of heat. Therefore, the amount of heating in the axial direction of the image of the paper can be freely controlled, and the fixing quality in the axial direction can be stabilized.

Further, the heating roller 182a has a central heat distribution heater 1822 and end heat distribution heaters 1823 and 1824 having different heat distributions in the axial direction. Therefore, the amount of heating in the axial direction of the image of the paper can be freely controlled, and the fixing quality in the axial direction can be stabilized.

Further, the control unit 11 controls the amount of heating in the axial direction of the heating roller 182 based on the difference in the measured glossiness of the measured images of the image measurement areas AR10 and AR20. Therefore, the glossiness of the images in the image measurement areas AR10 and AR20 can be made the same, and the fixing quality in the axial direction can be stabilized.

(Second Embodiment)
A second embodiment according to the present invention will be described with reference to FIGS. 13 to 15. FIG. 13 is a diagram showing a schematic configuration of the image measuring device 300a. FIG. 14 is a side view showing the image load applying unit 34a. FIG. 15 is a diagram showing the amount of heat with respect to the adhesion strength.

The device configuration of this modification uses the image forming device 1 as in the first embodiment. However, the image forming apparatus 1 includes an image measuring apparatus 300a instead of the image measuring apparatus 300. Further, in the image forming apparatus 1, the same reference numerals are given to the same parts as those in the first embodiment, and the description thereof will be omitted.

As shown in FIG. 13, in the image measuring device 300a, the sensor 32, the image load applying portion 34a, and the sensor 33 are arranged in this order from upstream to downstream in the paper passing direction. The sensors 32 and 33 are included in the image measuring unit 21.

The sensors 32 and 33 are optical sensors that irradiate the toner (image) T formed and fixed on the conveyed paper P with light, detect the reflected light, scan the toner (image) T, and acquire pixel values (image data). Is. As shown in FIG. 14, the image load applying portion 34a has a contact portion 341, and applies a load to the toner TN of the paper P measured by the sensor 32 by the contact portion 341 to scrape the toner TN. This scraping amount represents the adhesion strength of the toner TN to the paper P and changes depending on the fixing state. Therefore, the fixing state can be determined by the scraping amount and reflected in the heating amount. The contact portion 341 is a non-woven fabric or an eraser as an elastic body, but the contact portion 341 is not limited to this, and may be, for example, a contact portion having a structure for adhering and peeling tape. The adhesive strength of the toner TN can also be evaluated by peeling. As an example of the index of the adhesion strength of the toner as a feature amount indicating the fixing state, the adhesion strength [%] obtained by calculating the ratio of the image density after the load is applied to the image density before the load is applied is used.

For example, it is assumed that patches pb, pg, and pr as shown in FIG. 6 are formed on the paper P, the contact portion 341 scrapes the toner TN of the patches pb, pg, and pr, and the sensors 32 and 33 are used. Image data of patches pb, pg, pr shall be detected. This is to remove the toner TN of a normal image on the paper P so that the image density of the image is not affected.

The image measuring unit 21 has an image density corresponding to the image data of the toner TN of the paper P before the load applied detected by the sensor 32 and the image density of the paper P after the load applied by the image load applying unit 34a detected by the sensor 33. The adhesion strength is calculated and output to the control unit 11 based on the image density corresponding to the image data of the toner TN.

FIG. 15 shows the amount of heating with respect to the adhesion strength. When the adhesion strength measured by the image measuring unit 21 is set to the target adhesion strength, as shown by the arrow in the figure, the target is based on the heating amount of the heating roller 182 of the fixing unit 18 corresponding to the measured adhesion strength. The heating amount may be increased by the amount of deviation from the heating amount.

As the operation of the image forming apparatus 1, the same process as the first heating amount control process of the first embodiment of FIG. 11 is executed. However, in step S10, the control unit 11 calculates the reference adhesion strength as the target adhesion strength corresponding to the image density of the image data of the job instead of the reference glossiness. In step S11, the control unit 11 measures the adhesion strength of the measurement areas (image measurement areas AR10 and AR20) by the image measurement unit 21. In step S12, the control unit 11 compares the reference adhesive strength with the measured adhesive strength. Further, similarly to the second heating amount control process of FIG. 11, even if the adhesion strengths of the images in the image measurement areas AR10 and AR20 are compared and the heating amount is controlled so that these adhesion strengths are the same. good.

As described above, according to the present embodiment, the image measuring unit 21 includes an image loading unit 34a that applies a load to the image surface of the paper, and a sensor 32 that measures the image density as a feature amount of the image before the load is applied. It has a sensor 33 for measuring the image density as a feature amount of the image after applying a load, and measures the adhesion strength of the image on the paper based on the measured values of the image density of the sensors 32 and 33. Output. The control unit 11 controls the heating amount of the heating roller 182 based on the measured value of the adhesion strength. Therefore, the fixing quality of the image on the paper can be stabilized so that the adhesion strength of the image on the paper after fixing is the same.

Further, the image load applying portion 34a has a contact portion 341 that contacts the image surface of the paper. The contact portion 341 is a non-woven fabric, an elastic body, or a tape. Therefore, the load can be reliably applied by contacting the image surface of the paper.

Further, the image forming unit 17 forms patches pb, pg, pr in the image measurement areas AR10 and AR20 outside the normal image area of the paper as shown in FIG. The image load applying unit 34a applies a load to the toner TN of the patches pb, pg, and pr. Therefore, it is possible to prevent deterioration of the image quality in the normal image area without imposing a load on the normal image area of the paper.

(Second modification)
A second modification as a modification of the second embodiment will be described with reference to FIGS. 16 and 17. FIG. 16 is a side view of the image measuring device 300b. FIG. 17 is a side view of the image load applying portion 34b in the main scanning direction.

The device configuration of this modification uses the image forming device 1 as in the second embodiment. However, the image forming apparatus 1 is provided with the image measuring apparatus 300b instead of the image measuring apparatus 300a. Further, in the image forming apparatus 1, the same reference numerals are given to the same parts as those in the second embodiment, and the description thereof will be omitted.

As shown in FIG. 16, in the image measuring device 300b, the sensor 32, the image load applying portion 34b, and the sensor 33 are arranged in this order from upstream to downstream in the paper passing direction. FIG. 16 is a side view along the paper passing direction.

As shown in FIGS. 16 and 17, the image load applying portion 34b includes a fine particle spraying portion 342, a cooling fan 343, and filters 344 and 345, and fine particles are applied to the toner TN of the paper P like sandblasting. Spray and scrape. FIG. 17 is a side view along a direction perpendicular to the paper passing direction (main scanning direction).
The fine particle spraying unit 342 sprays fine particles on the patch toner of the toner TN of the paper P measured by the sensor 32 and scrapes it under the control of the control unit 11. The fine particle spraying portion 342 uses a blasting agent (fine particles) of metal or ceramic particles using a resin as a binder as a condition for obtaining the effect, and the particle size of the fine particles is 10 [μm] to 100 [μm], and compressed air. Therefore, the particles are sprayed at a pressure of 0.1 [Mpa] to 1 [Mpa]. Since the toner particle size is a little less than 10 [μm], the particle size of the fine particles is 1 to 10 times larger, and the particles can be recovered by the filters 344 and 345 for collecting the scattered toner.

The cooling fan 343 is a fan that cools the inside of the machine by discharging the air in the image measuring device 300b to the outside under the control of the control unit 11. The filter 344 is arranged inside the image measuring device 300b of the cooling fan 343, filters the toner particles from the air containing the scattered toner, and filters the fine particles sprayed by the fine particle spraying unit 342. The filter 345 collects the toner particles that have been filtered by the filter 344 and dropped, and also collects the fine particles. In the image measuring device 300b, the fine particles are collected by using the cooling fan 343 for collecting toner and the filters 344 and 345 as the existing air flow in the device, and there is no need to add a new mechanism.

For example, it is assumed that patches pb, pg, and pr as shown in FIG. 6 are formed on the paper P, and as shown in FIG. 17, the fine particle spraying portion 342 is not the toner TN1 of the normal image but the toner. It is assumed that the toner TN2 of the toner TN2 of the patches pb, pg, pr outside the TN1 is scraped, and the sensor 32 and the sensor 33 detect the image data of the toner TN2 of the patches pb, pg, pr.

The measurement of the adhesion strength of the toner TN of the paper P and the control of the heating amount of the fixing portion 18 in the image measuring apparatus 300b are the same as those of the image measuring apparatus 300a of the second embodiment except that the load is applied by the fine particle spraying unit 342. The same is true.

As described above, according to the present modification, the image load applying portion 34b has a fine particle spraying portion 342 that sprays fine particles on the image surface of the paper. Therefore, it is possible to reliably apply a load by spraying fine particles on the image surface of the paper.

Further, the image load applying unit 34b has a cooling fan 343 and filters 344 and 345 as a collecting unit for collecting the sprayed fine particles by air flow. Therefore, the fine particles can be reliably recovered, and the fine particles can be recovered by using the existing recovery unit of the scattered toner, the structure of the image forming apparatus 1 can be simplified, and the cost can be reduced.

The description in the above-described embodiment and modification is an example of a suitable image forming apparatus and program according to the present invention, and is not limited thereto. For example, a configuration in which a plurality of configurations of at least a part of the above-described embodiment and modification may be combined may be used.

Further, in the first embodiment and the first modification, the image measuring unit 21 measures the glossiness as a feature amount of the image on the paper, but the present invention is not limited to this. For example, the sensor 31 is an optical sensor that scans an image on paper to acquire pixel values (image data), and the image measuring unit 21 uses the image data acquired by the sensor 31 as a special amount of color for the image. (Measurement color) may be output as a measurement result. The control unit 11 uses the measurement color measured from the image on the paper by the image measurement unit 21 as a reference value of the color corresponding to the image density in the same manner as in the first heating amount control process of the first embodiment. The heating amount of the heating roller 182 of the fixing portion 18 may be controlled according to the deviation amount by comparing with the reference color of the above. Further, the control unit 11 compares the measurement colors of the image measurement areas AR1 and AR2 measured from the image of the paper by the image measurement unit 21 in the same manner as in the second heating amount control process of the first modification. The heating amount of the heating roller 182 (at the front side of the device and the end on the back side of the device) of the fixing portion 18 may be controlled according to the difference. According to this configuration, the fixing quality of the image on the paper can be stabilized so that the colors of the image on the paper after fixing are the same.

Further, the detailed configuration and detailed operation of each part constituting the image forming apparatus 1 in the above embodiments can be appropriately changed without departing from the spirit of the present invention.

1 Image forming device 100 Image forming device main body 11 Control unit 12 Operation unit 13 Display unit 14 Storage unit 15 Communication unit 16 Image processing unit 17 Image forming unit 17Y, 17M, 17C, 17K Image forming unit 171 Photoreceptor drum 172 Charging unit 173 Exposure section 174 Development section 175 Primary transfer roller 176 Cleaning section 18 Fixing section 181 Fixing roller 182, 182a Heating roller 1821 Heater section 1822 Central heat distribution heater 1823, 1824 End heat distribution heater 183 Fixing belt 184 Pressurizing roller 185 Motor 19 Transport unit 20 Paper feed unit T1 to T3 Paper feed tray 200 Paper feed device 21 Image measurement unit 300, 300a, 300b Image measurement device 31, 32, 33 Sensor 34a, 34b Image load application unit 341 Contact unit 342 Fine particle spraying unit 343 Cooling Fan 344,345 Filter 22 Post-processing unit 400 Post-processing device 23 Bus T4 Output tray

Claims (20)

An image forming part that forms an image on paper,
A fixing portion having a heating portion in which the amount of heating can be changed, and fixing an image on the image-formed paper by heating and pressurizing by the heating portion, and a fixing portion.
An image measuring unit that measures the feature amount of the image on the paper after fixing and outputs the measured value of the feature amount, and the image measuring unit.
An image forming apparatus including a control unit that controls the heating amount of the heating unit based on the measured value of the feature amount by the image measuring unit. The image forming apparatus according to claim 1, wherein the image measuring unit has an optical sensor and outputs a measured value of an image feature amount based on the detected amount detected by the sensor. The sensor irradiates the image on the paper with irradiation light, detects the amount of reflected light, and determines the amount of reflected light.
The image forming apparatus according to claim 2, wherein the image measuring unit outputs a glossiness of an image corresponding to the amount of the detected reflected light as a measured value. The sensor detects the pixel value of the image on the paper and
The image forming apparatus according to claim 2, wherein the image measuring unit outputs a color of an image corresponding to the detected pixel value as a measured value. The control unit compares the measured value of the feature amount measured by the image measurement unit with the preset reference value of the feature amount, and controls the heating amount of the heating unit based on the comparison result. The image forming apparatus according to any one of claims 1 to 4. The image forming apparatus according to claim 5, wherein the reference value is set for each paper information. The image forming apparatus according to claim 6, wherein the control unit calculates the paper information from the measurement result of the position where there is no image on the paper by the image measuring unit. The image measuring unit measures the feature amounts of a plurality of image regions located in the direction perpendicular to the paper passing direction of the paper, and measures the features.
The image forming according to any one of claims 1 to 7, wherein the control unit controls the amount of heating in the axial direction of the heating unit based on the measured values of the measured feature amounts of the plurality of image regions. Device. The image forming apparatus according to claim 8, wherein the heating unit can control the heat generation distribution along the axial direction perpendicular to the paper passing direction. The image forming apparatus according to claim 9, wherein the heating unit is arranged along the axial direction and has a plurality of divided heating units capable of independently controlling the heating amount. The image forming apparatus according to claim 9, wherein the heating unit has a plurality of heat distribution heating units having different heat distributions in the axial direction. The image according to any one of claims 8 to 11, wherein the control unit controls the heating amount in the axial direction of the heating unit based on the difference between the measured values of the feature amounts of the measured plurality of regions. Forming device. The image forming portion forms a patch outside the normal image area of the paper.
The image forming apparatus according to any one of claims 1 to 12, wherein the image measuring unit measures a feature amount of the patch. The image forming apparatus according to any one of claims 1 to 13, wherein the image measuring unit measures a feature amount of an image measuring area in a normal image area of the paper. The image measuring unit
An image load applying portion that applies a load to the image surface of the paper,
The first sensor that measures the feature amount of the image before applying the load, and
It has a second sensor that measures the feature amount of the image after the load is applied, and based on the measured value of the first sensor and the measured value of the second sensor, the paper Output the measured value of the adhesion strength of the image,
The image forming apparatus according to claim 1, wherein the control unit controls the heating amount of the heating unit based on the measured value of the adhesion strength. The image load applying unit is
The image forming apparatus according to claim 15, which has a contact portion that comes into contact with the image surface of the paper. The image forming apparatus according to claim 16, wherein the contact portion is a non-woven fabric, an elastic body, or a tape. The image forming apparatus according to claim 15, wherein the image load applying unit is a fine particle spraying unit that sprays fine particles onto the image surface of the paper. The image forming apparatus according to claim 18, wherein the image load applying unit has a collecting unit that collects the sprayed fine particles by air flow. Computer,
It has a heating part whose heating amount can be changed, and the image is fixed on the paper image-formed by the image forming part by heating and pressurizing by the heating part. Features of the image of the paper after being fixed by the fixing part. A control unit that controls the heating amount of the heating unit based on the measured value of the feature amount measured by the image measuring unit that measures the amount and outputs the measured value of the feature amount.
A program to function as.

Images