JP2015114510A - Image formation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image formation device capable of preventing the energy used in fixing operation from being wastefully consumed, by setting a fixation temperature based on an amount of developer needed for printing and controlling a fixation unit so that the fixation target temperature is reached.SOLUTION: There is provided an image formation device equipped with a fixation unit for thermally fixing a developer image based on image data onto a medium, the image formation device comprising: a temperature detection unit for detecting a temperature of the fixation unit; a layer thickness calculation unit for calculating a layer thickness of the developer image; a fixation temperature calculation unit for calculating a fixation target temperature from the layer thickness calculated by the layer thickness calculation unit; and a fixation control unit for controlling thermal fixation by the fixation unit from the fixation target temperature calculated by the fixation temperature calculation unit and the temperature detected by the temperature detection unit.

Description

  The present invention relates to an image forming apparatus including a fixing unit that thermally fixes a developer image based on image data onto a medium.

  For example, a plurality of image forming units that perform image formation using developers of different colors such as cyan, magenta, yellow, and black are arranged side by side on the medium conveyance path, and images corresponding to the respective colors are sequentially superimposed on the medium. In an image forming apparatus for forming an image, a medium on which a developer image is formed is passed through a fixing unit including a fixing roller heated at high temperature and a pressure roller provided to face the fixing roller. Some fix the developer image by heat.

  In such an image forming apparatus, for example, the fixing temperature and the conveyance speed of the medium are determined depending on the fixing performance in monochrome printing using a developer of only black and color printing using a developer of a plurality of colors. Are known that perform image formation by changing (see, for example, Patent Document 1).

JP 2007-57870 A

  However, in color printing according to the prior art, for example, printing of a photograph or the like having a high image density and a large amount of developer required for printing, or printing of a text or the like whose image density is not so high and the amount of developer required for printing is not necessarily large. Even if there is a slight difference in the amount of developer required for printing, since fixing is performed at a constant temperature, energy used for the fixing operation is wasted.

  The present invention has been made in view of such a situation, and an object of the present invention is to set a fixing target temperature based on the amount of developer required for printing and to control the fixing unit so as to be the target fixing temperature. Thus, an image forming apparatus capable of preventing wasteful consumption of energy used for the fixing operation is provided.

  In order to solve the above problems, an image forming apparatus according to the present invention is an image forming apparatus including a fixing unit that thermally fixes a developer image based on image data onto a medium, and detects the temperature of the fixing unit. A temperature detecting unit that calculates a layer thickness of the developer image, a fixing temperature calculating unit that calculates a fixing target temperature from the layer thickness calculated by the layer thickness calculating unit, and the fixing temperature And a fixing control unit that controls thermal fixing by the fixing unit based on the fixing target temperature calculated by the calculating unit and the temperature detected by the temperature detecting unit.

  According to the present invention, by setting a fixing target temperature based on the amount of developer required for printing and controlling the fixing unit so as to reach the target fixing temperature, energy used for the fixing operation is wasted. An image forming apparatus capable of preventing this can be provided.

2 is a block diagram illustrating a functional configuration of the image forming apparatus. FIG. FIG. 5 is a correlation diagram illustrating a relationship between a toner layer thickness and a fixing target temperature. 3 is a flowchart for explaining the operation of the image forming apparatus. FIG. 6 is a schematic diagram illustrating temperature control of a fixing unit by a fixing control unit. 2 is a block diagram illustrating a functional configuration of the image forming apparatus. FIG. 3 is a flowchart for explaining the operation of the image forming apparatus. 3 is a flowchart for explaining the operation of the image forming apparatus.

  Embodiments of the present invention will be described below with reference to the drawings. In addition, this invention is not limited to the following description, In the range which does not deviate from the summary of this invention, it can change suitably.

[First embodiment]
In the description of the first embodiment, the image forming apparatus 101 capable of transmitting / receiving information to / from a host host 116 such as a PC (Personal Computer) via the interface unit 109 will be described. The image forming apparatus 101 is an image forming apparatus capable of forming a toner image as a developer image based on image data received from the host host 116 on a medium.

  FIG. 1 is a block diagram illustrating a functional configuration of the image forming apparatus 101 according to the first embodiment. The image forming apparatus 101 includes a control unit 102, a ROM (Read Only Memory) 106, a RAM (Random Access Memory) 107, an EEPROM (Electrically Erasable Programmable Read Only Memory) 108, an interface unit 109, and an operation panel 110. The image forming unit 111 and the fixing unit 112 are provided.

  The control unit 102 includes an arithmetic device such as a CPU (Central Processing Unit) and controls the entire image forming apparatus 101 in an integrated manner. The control unit 102 also has a fixing control unit 103 that controls the fixing unit 112, and a toner layer thickness as a developer required for forming a toner image formed on the medium based on image data received from the host host 116. And a fixing temperature calculation unit 105 that calculates how many times the fixing target temperature of the fixing unit 111 is set.

  The ROM 106 stores a control program and various setting values used when the control unit 102 comprehensively controls the image forming apparatus 101. The control unit 102 implements a function by executing a control program stored in the ROM 106.

  The RAM 107 is used as a working area of the CPU provided in the control unit 102, and temporarily stores received image data and the like.

  The EEPROM 108 is, for example, speed error data such as the medium conveyance speed of the fixing unit 111 written at the time of shipment from the factory, output error data of an output value of a thermistor serving as a temperature detecting unit provided in the fixing unit 112, apparatus life information, and the like. Is stored.

  The interface unit 109 includes, for example, a connection unit that enables connection with an electric signal line such as a LAN (Local Area Network) port or a USB (Universal Serial Bus) port, an interface card that controls the connection unit, and the like. Information transmission / reception with 116 is controlled.

  The operation panel 110 includes, for example, a display unit such as an LCD (Liquid Crystal Display) and an input unit such as a touch panel, and accepts display of the apparatus status, the remaining amount of consumables, and the like, and input of print setting values by the user. .

  The image forming unit 111 includes a plurality of image forming units (not shown) that perform image formation using different toners such as cyan, magenta, yellow, and black, and sequentially superimposes toner images corresponding to the respective colors on the medium. A color image is formed.

  The fixing unit 112 is a member that heat-fixes the toner image by applying heat and pressure to the toner image formed on the medium in the image forming unit 111. Such a fixing unit 112 includes at least a heating roller 113, a heater 114, and a thermistor 115.

  For example, the heating roller 113 is formed by coating a hollow cylindrical cored bar made of aluminum or the like with a heat-resistant elastic layer of silicone rubber and covering a PFA (tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer) tube thereon. The heating member is formed by the above-mentioned, and is supported so as to be rotatable with respect to the frame of the fixing device 112 (not shown). The heater 114 is a heating member made of, for example, a halogen lamp or the like, and heats the heating roller 113 from the inside based on control by the fixing control unit 103. The thermistor 115 is disposed near the surface of the heating roller 113 and detects the temperature of the surface of the heating roller 113. The thermistor 115 detects the temperature of the surface of the heating roller 113 as an analog voltage value based on a change in resistance value. The analog voltage value detected by the thermistor 115 is output to the fixing control unit 103 of the control unit 102 and used for controlling the fixing unit 112. In other words, the fixing control unit 103 controls ON / OFF of the heater 114 based on the temperature of the surface of the heating roller 113 detected by the thermistor 115 and the fixing target temperature calculated by the fixing temperature calculation unit 105, thereby heating the heating roller 112. The surface temperature is maintained at a predetermined fixing temperature.

  Next, the operation according to the present embodiment will be described. FIG. 2 is a correlation diagram for explaining the relationship between the toner layer thickness required for forming the toner image formed on the medium based on the image data received from the host host 115 and the fixing target temperature calculated by the fixing temperature calculation unit. FIG. 3 is a flowchart for explaining the operation according to the present embodiment. FIG. 4 is a schematic diagram for explaining temperature control of the fixing unit 112 by the fixing control unit 103.

  First, FIG. 2 will be described. As described above, the image forming apparatus 101 can form a color image by sequentially superimposing a plurality of color toner images of cyan, magenta, yellow, and black. In the present embodiment, the overlapping toners are referred to as layers. In the present embodiment, it is optimal for monochrome printing or monochrome printing (single layer) using only one kind of toner of cyan, magenta, and yellow (single layer) and for color printing (multiple layers). Different fixing target temperatures. FIG. 2 is a diagram showing the correlation between the layer thickness (layer thickness) and the fixing target temperature. In this embodiment, when the layer thickness = 1, the fixing target temperature is the fixing temperature A, and the layer thickness = In the case of 2, the fixing target temperature is the fixing temperature B, and when the layer thickness is 3 or more, the fixing target temperature is the fixing temperature C.

  The flowchart of FIG. 3 will be described below based on the correlation between the layer thickness and the fixing target temperature described in FIG.

  When the image data is transmitted from the upper host 116 shown in FIG. 1, the image forming apparatus 101 receives this via the interface unit 109 (step S201).

  When the image data is received via the interface unit 109, the control unit 102 stores the received image data in the RAM 107 (step S202).

  Next, in step S203, the layer thickness calculation unit 104 counts the video count values of cyan, magenta, yellow, and black for each dot of one page of image data stored in the RAM 107, and uses the maximum value. Calculated as layer thickness.

  Based on the layer thickness calculated by the layer thickness calculation unit 104, the control unit 102 determines how many layers the layer thickness is (step S204). When the control unit 102 determines that the layer thickness is one layer (step S205), the fixing temperature calculation unit 105 calculates the fixing target temperature as the fixing temperature A (step S208). Similarly, when the control unit 102 determines that the layer thickness is two layers (step S206), the fixing temperature calculation unit 105 calculates the fixing target temperature as the fixing temperature B (step S209), and the control unit 102 determines the layer thickness. Is determined to be three layers or more (step S207), the fixing temperature calculation unit 105 calculates the fixing target temperature as the fixing temperature C (step S210).

  Then, the fixing control unit 103 controls the temperature of the fixing unit 112 based on the target fixing temperature calculated by the fixing temperature calculating unit 105.

  Here, the temperature control of the fixing unit 112 by the fixing control unit 103 will be described with reference to FIG. As shown in FIG. 4, the fixing control unit 103 controls the transmission of a signal for turning on / off the heater 114 of the fixing unit 112 to turn on the heater 114. When the heater 114 is turned on, the heating roller 113 is warmed and the surface temperature rises. The temperature of the surface of the heating roller 113 is detected by the thermistor 115 disposed in the vicinity of the surface (step S211 in FIG. 3).

  The fixing control unit 103 performs control until the temperature of the surface of the heating roller 113 reaches a predetermined fixing target temperature and is maintained while repeating the transmission of a signal for turning the heater 114 ON / OFF.

  When the temperature of the surface of the heating roller 113 detected by the thermistor 115 reaches the fixing target temperature and is maintained (Yes in step S213 in FIG. 3), the fixing control unit 103 notifies the control unit 102 of this, Upon receiving the notification, the control unit 102 controls the image forming unit 111 to start a printing operation (step S214). On the other hand, when the temperature of the surface of the heating roller 113 detected by the thermistor 115 does not reach the fixing target temperature and is not maintained (No in step S213 in FIG. 3), the fixing control unit 103 transmits a signal for turning on the heater 114. The temperature of the surface of the heating roller 113 reaches the fixing target temperature as it is, and waits until this is maintained (step S212 in FIG. 3).

  Conventionally, in order to perform stable heat fixing on all image data, for example, heat fixing has been performed at a fixing temperature C having the highest fixing target temperature. In the first embodiment, thermal fixing is performed at a fixing temperature B lower than the fixing temperature C when the layer thickness is two layers, and at a fixing temperature A lower than the fixing temperature when the layer thickness is one layer. Therefore, it is possible to prevent wasteful consumption of energy used for the fixing operation, and power saving can be achieved.

[Second Embodiment]
FIG. 5 is a block diagram illustrating a functional configuration of the image forming apparatus 101 ′ according to the second embodiment. In addition to the configuration of the image forming apparatus 101 according to the first embodiment, the image forming apparatus 101 ′ according to the present embodiment determines whether the data transmitted from the upper host 116 is text data or image data. And a layer thickness density calculation unit 402 as an image density calculation unit that calculates the layer thickness average of pages from the layer thickness of each dot calculated from the image data transmitted from the host host 116. . Since other configurations are the same as those of the first embodiment, the same members are denoted by the same reference numerals, and description thereof is omitted.

  Next, the operation according to the present embodiment will be described. FIG. 6 is a flowchart for explaining an example in which the process branches depending on whether the data transmitted from the upper host 116 is text data or image data, and FIG. 7 illustrates an image transmitted from the upper host 116. It is a flowchart explaining the example which a process branches as a result of calculating the layer thickness average of a page from the layer thickness for every dot calculated from data.

  First, the flowchart of FIG. 6 will be described. When the image data is transmitted from the upper host 116 shown in FIG. 5, the image forming apparatus 101 ′ receives this via the interface unit 109 (step S601).

  When image data is received via the interface unit 109, the control unit 102 stores the received image data in the RAM 107 (step S602).

  In step S <b> 603, the data type determination unit 401 determines the type of image data stored in the RAM 107. If it is determined that the image data is text data (YES in step S604), the data type determination unit 401 notifies the fixing temperature calculation unit 105 to that effect. Receiving the notification, the fixing temperature calculation unit 105 calculates the fixing target temperature as the fixing temperature A (step S607).

  On the other hand, when it is determined that the image data is not text data but image data (NO in step S604), the data type determination unit 401 notifies the layer thickness calculation unit 104 to that effect. Upon receiving the notification, the layer thickness calculation unit 104 counts the video count values of cyan, magenta, yellow, and black for each dot of one page of the image data stored in the RAM 107, and uses the maximum value as the layer thickness. Calculate (step S605).

  Based on the layer thickness calculated by the layer thickness calculation unit 104, the control unit 102 determines how many layers the layer thickness is (step S606). When the control unit 102 determines that the layer thickness is one layer (step S607), the fixing temperature calculation unit 105 calculates the fixing target temperature as the fixing temperature A (step S610). Similarly, when the control unit 102 determines that the layer thickness is two layers (step S608), the fixing temperature calculation unit 105 calculates the fixing target temperature as the fixing temperature B (step S611), and the control unit 102 determines the layer thickness. Is determined to be three layers or more (step S609), the fixing temperature calculation unit 105 calculates the fixing target temperature as the fixing temperature C (step S612).

  Then, the fixing control unit 103 controls the temperature of the fixing unit 112 based on the target fixing temperature calculated by the fixing temperature calculating unit 105. Note that the operations according to steps S613 to S614 can be performed in the same manner as the operations described with reference to steps S211 to S214 in FIG.

  Next, the flowchart of FIG. 7 will be described. When the image data is transmitted from the upper host 116 shown in FIG. 5, the image forming apparatus 101 ′ receives this via the interface unit 109 (step S701).

  When image data is received via the interface unit 109, the control unit 102 stores the received image data in the RAM 107 (step S702).

  Next, in step S703, the layer thickness calculation unit 104 counts the video count values of cyan, magenta, yellow, and black for each dot of one page of image data stored in the RAM 107, and calculates the maximum value. Calculated as layer thickness. Subsequently, the layer thickness density calculation unit 402 calculates the average layer thickness of pages based on the layer thickness calculated by the layer thickness calculation unit 104 (step S704).

  Based on the layer thickness average calculated by the layer thickness density calculation unit 402, the control unit 102 determines how many layers the layer thickness average has (step S705). When the control unit 102 determines that the average layer thickness is 1 layer or less (step S706), the fixing temperature calculation unit 105 calculates the fixing target temperature as the fixing temperature A (step S709). Similarly, when the control unit 102 determines that the average layer thickness is greater than one layer and equal to or less than two layers (step S707), the fixing temperature calculation unit 105 calculates the fixing target temperature as the fixing temperature B (step S710). When the control unit 102 determines that the average layer thickness is larger than two layers (step S708), the fixing temperature calculation unit 105 calculates the fixing target temperature as the fixing temperature C (step S711).

  Then, the fixing control unit 103 controls the temperature of the fixing unit 112 based on the target fixing temperature calculated by the fixing temperature calculating unit 105. Note that the operations according to steps S712 to S715 can be performed in the same manner as the operations described with reference to steps S211 to S214 in FIG.

  As described above, according to the second embodiment, although the received data is text data, since it is a color image, the layer thickness is calculated to be thick, and as a result, at a high fixing temperature. In cases such as when heat fixing is performed, or because there are locally thick parts, the layer thickness of the entire page is calculated to be thick, and as a result, heat fixing at a high fixing temperature is performed. In such a case, it is possible to perform heat fixing at a more suitable low fixing temperature, so that energy used for the fixing operation can be prevented from being wasted and power saving can be achieved. be able to.

  In the description of the present invention, an example in which three stages of fixing target temperatures are set according to the layer thickness (average) has been described. However, the present invention is not limited to this, and the fixing target temperature may be set more finely.

  The present invention can be applied not only to a printer as an image forming apparatus but also to a facsimile machine, a multi-function machine, and the like provided with a mechanism for thermally fixing a toner image formed on a medium.

101, 101 'Image forming apparatus 102 Controller 103 Fixing controller 104 Layer thickness calculator 105 Fixing temperature calculator 106 ROM
107 RAM
108 EEPROM
109 Interface Unit 110 Operation Panel 111 Image Forming Unit 112 Fixing Unit 113 Heating Roller 114 Heater 115 Thermistor 116 Host Host 401 Data Type Determination Unit 402 Layer Thickness Density Calculation Unit

Claims (5)

An image forming apparatus including a fixing unit that thermally fixes a developer image based on image data on a medium,
A temperature detection unit for detecting the temperature of the fixing unit;
A layer thickness calculator for calculating a layer thickness of the developer image;
A fixing temperature calculating unit that calculates a fixing target temperature from the layer thickness calculated by the layer thickness calculating unit;
An image forming apparatus comprising: a fixing control unit that controls thermal fixing by the fixing unit based on the target fixing temperature calculated by the fixing temperature calculating unit and the temperature detected by the temperature detecting unit. An image density calculation unit for calculating an image density of the developer image;
The fixing temperature calculation unit calculates the fixing target temperature from the layer thickness calculated by the layer thickness calculation unit and the image density calculated by the image density calculation unit. Image forming apparatus.   The image according to claim 1, wherein the layer thickness calculation unit counts a video count value corresponding to a developer included in the image data, and calculates the maximum value as a layer thickness of the developer image. Forming equipment. A receiving unit for receiving data transmitted from an external device;
The image forming apparatus according to claim 1, further comprising: a data type determining unit that determines whether the data received via the receiving unit is text data or image data.   When the data received by the data type determination unit is text data, the fixing control unit detects heat from the fixing unit based on the preset fixing target temperature and the temperature detected by the temperature detection unit. The image forming apparatus according to claim 4, wherein fixing is controlled.