JP2006146065A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus capable of reducing cleaning defects in low-temperature environment with a low cost. <P>SOLUTION: The image forming apparatus includes a temperature detecting means 5, a microcontroller 9 which discriminates whether the temperature discriminated by the temperature detecting means 5 is lower than set temperature, and a means of suspending or skipping the execution of calibration wherein a toner pattern for density detection or color registration detection is formed when discriminating that the temperature is lower than the set temperature. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention has a cleaning device that removes a developer (hereinafter referred to as “toner”) on an image carrier by bringing a cleaning blade into contact with the rotating image carrier and has a calibration function such as image density measurement. The present invention relates to an image forming apparatus such as an electrophotographic copying machine and a printer provided.

  In a conventional electrophotographic image forming apparatus, the surface of an electrophotographic photosensitive member (hereinafter referred to as a photosensitive drum) is uniformly charged by a charging device, and the charged photosensitive drum surface is exposed by an exposure device to be static. An electrostatic latent image is formed. The electrostatic latent image is developed by a developing device to form a toner image, the toner image is transferred to a transfer material such as paper by a transfer device, and the toner image is permanently fixed on the transfer material by a fixing device. Is fixed and output. The toner remaining on the surface of the photosensitive drum after the transfer of the toner image is cleaned by a cleaning device and prepared for the next image forming operation.

  First, the cleaning device will be described. As a cleaning device for removing toner remaining on the surface of the photosensitive drum, a method using a blade is widely used from the viewpoints of downsizing of the device, no need of a driving source, and relatively low manufacturing cost. The blade is mainly configured by bonding or integrally molding a metal sheet metal as a support and a rubber member, and by pressing the tip of the rubber member against the surface of the photosensitive drum, the surface of the photosensitive drum remains. The scraped toner can be scraped off and removed from the drum surface.

  The physical properties of the cleaning blade and the manner of contact with the image carrier greatly depend on the ease of cleaning depending on the degree of adhesion of the transfer residual toner to the photosensitive drum, the surface property of the image photosensitive drum, and the like. Also, the cleaning performance is greatly affected by physical properties such as toner shape, particle size, and material. Therefore, it is necessary to select an appropriate blade and set an appropriate angle and contact load with respect to the image carrier. In the actual selection and setting of the cleaning blade, the optimum conditions are found through repeated trial and error.

  Furthermore, when multiple types of cleaning blades are used in the image forming apparatus, for example, there are variations in the production lots of cleaning blades during long-term production, production at multiple companies, etc., it is difficult to equalize the physical properties of each blade. There are optimum conditions for each of the cleaning blades, and the image forming apparatus is designed for each of the cleaning blades so as to satisfy the optimum conditions.

  As a material of the rubber member of the cleaning device, urethane rubber (polyester urethane elastomer or the like) is widely used mainly from the viewpoint of hardly scratching the surface of the photosensitive drum. However, when the toner remaining on the surface of the photosensitive drum after the toner image transfer is cleaned at a relatively low temperature where the hardness of the rubber member of the cleaning device is increased, the toner slips through the cleaning device and stains the charging device and the transfer material. May occur (cleaning failure).

  A polyester urethane elastomer mainly used as a rubber member of a cleaning device has increased hardness at a relatively low temperature, so that the force received from the photosensitive drum increases and the rubber elasticity also decreases. For this reason, the tip of the blade is chipped with the rotation of the photosensitive drum, or it follows the minute load fluctuation received from the photosensitive drum depending on the surface property of the photosensitive drum surface when the photosensitive drum surface is slid. As a result, residual toner is sandwiched in the contact area between the surface of the photosensitive drum and the rubber member tip, and from the periphery of the sandwiched toner. In some cases, other residual toner slips through (cleaning failure).

  The following various proposals have been made for such a defect problem related to a cleaning blade at a low temperature. There is one provided with a heater for warming the cleaning member (Patent Document 1).

  Also, a heater for heating the cleaning blade and a means for measuring the time after the main power is turned on are provided, the heater is turned on when the main power is turned on, and then the heater is turned off when a predetermined time is measured. There is a thing (refer patent document 2).

  Also, a temperature detection sensor and a pressing pressure driving means for the cleaning blade are provided. When the temperature detection sensor detects that the temperature is about 5 to 10 degrees Celsius, the amount of deflection of the cleaning blade is increased by the pressing pressure driving means. When it is detected that the temperature is 10 degrees Celsius or higher, there is a technique that prevents the occurrence of cleaning failure due to a decrease in temperature by reducing the deflection amount of the cleaning blade by the pressing force driving means. In addition, there is an apparatus that controls on / off of an LED lamp and a charging charger provided in front of the cleaning blade in accordance with a detection temperature of a temperature detection sensor (see Patent Document 3).

  In addition, there is provided an angle adjusting means and a temperature sensor capable of changing a contact angle formed between a cleaning blade and a contact surface of the photosensitive drum as an image carrier, and the contact angle according to a change in environmental temperature. There is one that controls the change (see Patent Document 4).

  Also, there is one that controls energization of a heater that warms the surface of the image carrier based on information from a temperature / humidity detection unit that detects environmental temperature and humidity around the image carrier (see Patent Document 5 and Patent Document 6).

  Further, there is an apparatus that includes an oscillating unit and a temperature detecting unit that vibrate the cleaning member, and controls the oscillating unit based on detected temperature information (see Patent Document 7 and Patent Document 8).

In addition, there are at least two types of cleaning means made of materials having different rebound resilience, and changing the material of the cleaning means based on information from an environmental sensor that detects environmental temperature and environmental humidity (see Patent Document 9).
Japanese Patent Laid-Open No. 6-186885 Japanese Patent No. 0376464 Japanese Patent Laid-Open No. 7-28369 Japanese Patent Laid-Open No. 11-095634 JP 2000-1313070 A JP 2002-268465 A JP 2003-038881 A JP 2003-038882 A JP 2003-323097 A

  However, in the above-described conventional image forming apparatus, a heater control circuit, a safety device, and the like are required in order to provide a heater on the photosensitive drum, the cleaning blade, and the like, and in order to change the vibration means and material of the cleaning blade. Since it is necessary to provide a separate additional device, there is a problem that the device becomes complicated and disadvantageous in terms of cost.

  In addition, since the color image forming apparatus performs calibration such as image density control and color misregistration correction control, cleaning and collection of a large amount of toner image transferred for density detection or color misregistration detection on a transfer belt or the like. Need to do.

  In this case, as described above, the cleaning blade that collects the toner increases in hardness at a relatively low temperature, and therefore increases the force received from the photosensitive drum and also decreases the rubber elasticity, thereby reducing the surface of the photosensitive drum. There is a problem that a phenomenon (cleaning failure) occurs in which residual toner is caught in the contact area between the rubber member and the tip of the rubber member, and other residual toner slips out from around the sandwiched toner.

  In other words, if the calibration is performed immediately after the power is turned on in the winter morning, there is a large amount of toner that must be collected, and a synergistic effect that the cleaning ability is reduced at low temperatures. There has been a problem that is more likely to occur.

  Further, when the image forming apparatus is under an environment of 10 degrees or less, particularly when the room temperature is suddenly raised by an air conditioner or the like from an environmental temperature such as 0 degrees Celsius (for example, 10 degrees Celsius), image formation is performed. It takes several hours for the internal temperature of the apparatus to rise to about 10 degrees Celsius, which is the same as the room temperature. Therefore, even when the room temperature rises from a very low temperature to a normal temperature, there is a problem that a defective cleaning may occur continuously. was there.

  SUMMARY An advantage of some aspects of the invention is that it provides an image forming apparatus capable of reducing a cleaning defect at a low cost in a low temperature environment.

In order to achieve the above object, an image forming apparatus of the present invention includes at least one image carrier that is rotationally driven, and a developing unit that develops a latent image on the image carrier and visualizes the toner image. Conveying means for carrying and conveying a recording material or a directly formed toner image, and a plurality of image formations arranged along the conveying direction of the conveying means to form a toner image on the recording material or on the conveying means In an image forming apparatus comprising: a cleaning unit that cleans the image carrier and the transport unit;
Temperature detecting means for detecting temperature; and temperature determining means for determining whether or not the temperature detected by the temperature detecting means is equal to or lower than a set value temperature. When it is determined that the calibration is performed, a means for holding or skipping the execution of the calibration for forming the test toner pattern on the conveying means is provided.

Further, the image forming apparatus of the present invention includes at least one image carrier that is rotationally driven, a developing unit that develops a latent image on the image carrier and visualizes it as a toner image, and a recording material or a direct formation. Conveying means for carrying and conveying the toner image formed thereon, a plurality of image forming means arranged along the conveying direction of the conveying means to form a toner image on the recording material or on the conveying means, and the image carrying In an image forming apparatus having a body and a cleaning unit for cleaning the transport unit,
Temperature detecting means for detecting temperature, temperature determining means for determining whether or not the temperature detected by the temperature detecting means is equal to or lower than a set value temperature, and calibration for detecting and correcting image density or color resist of the image And
When the temperature determining unit determines that the temperature is equal to or lower than a set value, the calibration is performed by forming a test toner pattern formed on the conveying unit to be smaller or less than that at the predetermined temperature or more. A parameter related to image formation is calculated by execution.

Further, the image forming apparatus of the present invention further comprises at least one image carrier that is rotationally driven, a developing unit that develops a latent image on the image carrier and visualizes it as a toner image, and a recording material or A conveying means for carrying and conveying a directly formed toner image; a plurality of image forming means arranged along the conveying direction of the conveying means to form a toner image on the recording material or on the conveying means; and In an image forming apparatus having an image carrier and a cleaning unit for cleaning the transport unit,
Temperature detecting means for detecting the temperature, and temperature determining means for determining whether or not the temperature detected by the temperature detecting means is equal to or lower than a set value temperature, and the temperature is not more than a predetermined value by the temperature determining means. If it is determined, the parameter related to image formation is calculated according to the information stored in the memory element, and the execution of the calibration for forming the test toner pattern on the conveying means is suspended or skipped. It is characterized by.

  As described above, according to the image forming apparatus of the present invention, it is possible to hold or skip the calibration that has been conventionally performed regardless of the environment temperature where the apparatus is installed in a low temperature environment. Therefore, in a low temperature environment, it becomes possible to not perform the cleaning process that is essential at the time of calibration. As a result, it is possible to skip the sequence for collecting the test toner used at the time of calibration, and it is possible to reduce defective cleaning that occurs in a low temperature environment where the cleaning blade is cured.

  Further, according to the image forming apparatus of the present invention, even when calibration is suspended or skipped in a low temperature environment, it can be executed in accordance with a subsequent change in environmental temperature. As a result, it is possible to optimize the image quality by executing an optimal calibration process under an environmental temperature where no cleaning failure occurs, and when the temperature of the temperature detection means rises. It is possible to calculate or detect the time for the temperature of the cleaning means to rise to a predetermined temperature regardless of the location of the temperature detection means for detecting the temperature.

  Furthermore, according to the image forming apparatus of the present invention, in contrast to the conventional calibration in which a test pattern having the same size is formed regardless of the environmental temperature where the apparatus is installed, in a low temperature environment. It is possible to form a test pattern having a smaller size or amount than that at the normal temperature. As a result, it is possible to reduce the amount that must be collected for the test toner used during calibration, and it is possible to reduce defective cleaning that occurs in a low temperature environment in which the cleaning blade is cured.

  Further, according to the image forming apparatus of the present invention, the calibration that has been conventionally performed regardless of the environmental temperature in which the apparatus is installed is related to the image formation according to the information stored in the memory element in the low temperature environment. It is possible to calculate parameters to be performed and to suspend or skip the calibration, so that it is possible to disable the cleaning process that is essential during calibration. As a result, it is possible to skip the sequence for collecting the test toner used at the time of calibration, and it is possible to reduce defective cleaning that occurs in a low temperature environment where the cleaning blade is cured.

  The best mode for carrying out the present invention will be described below based on examples.

  Hereinafter, Embodiment 1 of the present invention will be described in detail with reference to the drawings. The detailed description will be given in the order of the entire image forming apparatus, the cartridge apparatus including the cleaning apparatus, the color misregistration correction apparatus, the image density control apparatus, and the calibration apparatus.

  The image forming apparatus according to the first exemplary embodiment uses an environmental sensor to detect the environmental temperature of the image forming apparatus. If the temperature is equal to or lower than a predetermined temperature, engine calibration for detecting density or detecting color misregistration is suspended or skipped. However, the engine calibration is executed according to a predetermined process when a change in temperature rises.

(Image forming device)
The overall configuration of the image forming apparatus will be described with reference to FIG. In an electrophotographic color image forming apparatus, in order to reduce the time required for forming a multicolor image, a multi-color toner is provided by a color optical image forming unit including a scanning optical system for performing image exposure and a cartridge for each color. A so-called tandem type color image forming apparatus for forming an image has already been proposed. In this color image forming apparatus, for example, a conveyor belt that electrostatically adsorbs and conveys a transfer material and a plurality of photoconductors around the transfer belt are arranged, and a charger and a scanning optical system provided to face each photoconductor The toner images of a plurality of colors formed by the developing device are sequentially transferred to a transfer material.

  The tandem type color image forming apparatus includes a photosensitive drum (31C, 31Y, 31M, 31Bk) for four colors as an image carrier, and a transfer roller (32C, 32Y, 32M, 32Bk), the cartridge (8C, 8Y, 8M, 8Bk), the developing roller (33C, 33Y, 33M, 33Bk) that conveys the developer from the cartridge, and the photosensitive drum (31C, A laser scanner device (35C, 35Y, 35M, 35Bk) that forms an electrostatic latent image on 31Y, 31M, 31Bk) is provided for each color (yellow, magenta, cyan, black) image forming station.

  The sheet S that has passed the registration roller 37 is conveyed to the adsorption roller 36, and electrostatically adsorbs the sheet S to the electrostatic adsorption conveyance belt 29 formed endlessly by the adsorption roller 36, and is conveyed to the image forming unit. Start.

  A visible image is formed on the electrostatic latent image formed on each photoconductive drum 31 using the developer conveyed from each cartridge 8 by each developing roller 33, and transferred by a transfer roller 32 to which a bias is applied. Transferred onto the material. The transfer roller is for transferring a toner image onto the sheet S, and the toner image developed on the photosensitive drum is conveyed while the sheet is nipped and conveyed between the rotating photosensitive drum 31 and the transfer roller 32. Is transcribed. Note that the sheet S is given conveyance force by the photosensitive drum 31Bk, the transfer roller 32Bk, and the electrostatic adsorption conveyance belt 29 located on the most downstream side in the conveyance direction, and is sent to the fixing device 13 downstream in the conveyance path. The fixing device 13 is a unit for fixing the toner image on the sheet S, and a fixing driven roller 14 for heating the sheet, and a fixing pressure roller for conveying the sheet and applying a rotational force to the fixing driven roller 14 to pressurize the sheet. 15. A color image for four colors is fixed on the sheet S by the nip portion sandwiched between the fixing driven roller 14 and the fixing pressure roller 15. Thereafter, the sheet S is discharged to a discharge tray.

(Cartridge device)
Next, the process cartridge 8 will be described. FIG. 5 is an enlarged schematic configuration diagram of the process cartridges 8 for four colors. In the process cartridge 8, the photosensitive drum 31, the charging roller 23, the developing device 24, and the cleaning device 25 are unitized, and these components are assembled in a predetermined relationship with each other in the cartridge. The cartridge 8 is inserted into and attached to a predetermined part in the main body of the image forming apparatus in a predetermined manner, and can be removed from the main body.

  The toner remaining on the photosensitive drum 31 after the printing is completed is removed by a cleaning device 25 including a cleaning blade 51 made of an elastic blade and a developer collecting container for collecting the cleaned toner. The cleaning blade 51 is arranged so that the tip of the elastic blade is in the counter direction with respect to the rotation direction of the photosensitive drum 31. A sectional view of the cleaning blade 51 is shown in FIG. The cleaning blade 51 is configured by adhering an elastic blade 51b made of a rubber elastic body made of urethane rubber to a holder 51a made of a metal sheet metal.

  The developing device will be described. Toner 41 accommodated in a toner container, a developing roller 33 that carries the toner 41 on the outer peripheral surface and conveys it to a developing area formed with the photosensitive drum 31, and a toner supply that conveys and applies the toner 41 to the developing roller 33 A roller 43, a developing blade 44 for regulating the amount of toner so that the toner 41 applied by the toner supply roller 43 is carried on the developing roller 33 in an appropriate amount, and a developing roller for performing a developing process in the developing region The developing device 24 is configured by a developing bias applying means (not shown) connected to the image forming apparatus main body 33 and provided in the image forming apparatus main body.

  The developing roller 33 is configured by providing an elastic layer 33b including a base layer and a surface layer thereon around a cylindrical body 33a made of metal such as aluminum, an alloy thereof, or stainless steel. The base layer of the elastic layer 33b is made of rubber such as silicon rubber, polyurethane rubber, or NBR, and the surface layer is made of ether urethane, nylon (registered trademark), or the like. Of course, the structure is not limited thereto, and a structure in which a foam such as sponge is used for the base layer and a rubber elastic layer is formed on the surface layer is also possible. Further, the developing roller 33 is rotationally driven in the direction of arrow B in FIG. 5 by a developing roller driving unit (not shown) provided inside the image forming apparatus main body.

  For example, the developing blade 44 is formed by bonding or injection-molding a 1 mm thick polyamide elastomer elastic member to a phosphor bronze plate having a spring elasticity as a metal thin plate and having a thickness of 0.1 mm, and developing the elastic member surface. The roller 33 is in contact with the surface of the roller 33 at a predetermined linear pressure. The pressing force of the developing blade 44 against the developing roller 33 is maintained by a thin metal plate, the negatively chargeable toner 41 is charged by a polyamide elastomer, and a toner layer having a predetermined thickness is formed on the developing roller 33. .

  The toner supply roller 43 has a sponge structure or a fur brush structure in which fibers such as rayon and nylon (registered trademark) are planted on a cored bar. The toner is supplied to the developing roller 33, applied, and the remaining toner is peeled off. From this point, urethane foam 43b is provided on the metal core 43a, for example, an elastic roller having a diameter of 16 mm. The toner supply roller 43 made of an elastic roller is in contact with the developing roller 33 with a predetermined intrusion amount, and is rotationally driven in the same direction as the rotation direction B of the developing roller 33 (direction of arrow C in FIG. 5). Are driven and stopped in synchronization with the developing roller 33.

(Color shift correction device)
A color misregistration factor and a color misregistration correction method in the color image forming apparatus will be described.

  In a tandem color image forming apparatus, if the machine dimensions deviate from the design values due to assembly errors, part tolerances, thermal expansion of parts, etc. during device manufacture, colors such as main scanning position deviation and sub-scanning position deviation Each registration shift occurs.

  Also, in a scanning optical system using a polygon scanner, main scanning magnification deviation is likely to occur due to the positional relationship between the photosensitive drum and the scanner. In a fixed optical element such as an LED, the exposure beam emitted from the exposure element forms an image on the photoconductor while having a certain extent from each light emitting point, but the main scanning overall magnification is unlikely to fluctuate greatly. On the other hand, in the polygon scanner which is a scanning optical system, the exposure beam is scanned radially from the scanner. Therefore, if the distance between the scanner and the photosensitive drum changes, the image magnification in the main scanning direction changes to each color. It will vary significantly from station to station.

  Even when the laser writing position from the horizontal synchronizing signal is made constant for each station, the writing position is likely to change for each color for the same reason, and a positional shift in the main scanning direction occurs.

  Regarding the main items of such resist misalignment, the main scanning position misalignment, the sub-scanning position misalignment, and the main scanning magnification, a resist pattern is formed on the electrostatic attraction / conveying belt 29, and is divided by 2 in the main scanning direction. This is detected by an individual registration detection sensor (not shown), and fine adjustment of the main scanning and sub-scanning writing positions and image clocks for each station makes it possible to perform color registration with excellent accuracy and reproducibility. I do.

(Image density controller)
A density change factor and a density control method in the color image forming apparatus will be described.

  In a color image forming apparatus, it is known that the color and density of an output image may change while printing is performed for a long period of time. This is due to a change with time in printing characteristics of a printer or the like. In addition, such a change in printing characteristics generally includes individual differences between apparatuses such as printers including the above-described change over time. In this case, for example, a plurality of printers There also arises a problem that the colors of the printers in the connected image processing system are different. For example, in the case of a printer using an electrophotographic system as an image forming system for printing, laser exposure in an electrophotographic process, latent image formation on a photoreceptor, development with toner, toner image on an output medium such as paper The process of image transfer and fixing by heat is easily affected by the ambient temperature, humidity, and changes in the components, and the amount of toner that is finally fixed on the paper changes to change the color tone. Arise.

  In order to correct this variation, image density control is performed. Here, this image density control will be briefly described.

  Concerning image density control, density patch images of each color are formed on an intermediate transfer belt or electrostatic attraction conveyance belt, read by a density detection sensor, and fed back to process formation conditions such as high pressure conditions and laser power. A means for matching the maximum density and halftone gradation characteristics of each color is used.

  The density detection sensor irradiates the density patch with a light source and detects the reflected light intensity with a light receiving sensor. The signal of the reflected light intensity is processed by the CPU that is the control means and fed back to the process formation conditions.

  The purpose of image density control is to keep the maximum density (hereinafter referred to as Dmax) of each color constant and to keep the halftone gradation characteristics linear with respect to the image signal.

  The control of Dmax has a great meaning of keeping the color balance of each color constant and at the same time preventing scattering of overlaid characters due to excessive toner loading and fixing failure.

  On the other hand, halftone gradation control is performed in order to prevent a natural image from being formed due to a shift in output density with respect to an input image signal due to nonlinear input / output characteristics (γ characteristics) unique to electrophotography. Image processing that cancels the characteristics and keeps the input / output characteristics linear is performed. As described above, image density control is performed to maintain a constant image forming characteristic.

  In this embodiment, the color shift correction control and the image density control described above are collectively referred to as engine calibration.

(Engine calibration)
Next, the calibration function of the image forming apparatus in this embodiment will be described with reference to FIGS.

  FIG. 3 is a block diagram showing each module related to the calibration function of this embodiment. Reference numeral 1 denotes a printer as an example of an image forming apparatus. The printer 1 includes a printer controller 3, an operation panel 12, and a printer engine 2. The printer controller 3 receives print information from a host computer (not shown), and performs transmission / reception of predetermined data such as communication with the printer engine 2, transmission / reception of vertical synchronization signals and horizontal synchronization signals, transmission of image data, and the like. Execute printing. The operation panel 12 is a part directly having an interface function with the user, and various settings of the printer can be directly performed by a button operation from the user.

  The printer engine 2 includes an engine controller 4 that includes a microcontroller 9 that controls the printing process of the printer 1, an environmental sensor 5 that detects an environmental temperature in which the printer 1 is installed, an engine controller 4, and other electrical devices (not shown). A low voltage power source 6 for supplying power to a circuit board, actuators, etc., a fixing device thermistor 7 built in the fixing device for detecting the temperature of the fixing roller, a cartridge 8 having a charging device, a developing device, and a cleaning device, electrostatic It is composed of a dark detection registration sensor 16 that detects the density and positional deviation of the test toner pattern transferred onto the suction conveyance belt 29.

  The low-voltage power supply 6 is provided with a power switch 11, and power is supplied into the printer 1 when the power switch is turned on by the user. The cartridge 8 includes cartridges (8Bk, 8M, 8Y, 8C) that form image stations for four colors of black, magenta, yellow, and cyan. Each cartridge (8Bk, 8M, 8Y, 8C) includes a cartridge. Nonvolatile memory elements (26Bk, 26M, 26Y, 26C) for storing information are configured. The microcontroller 9 configured in the engine controller 4 incorporates a timer 10 and can measure time.

  Next, engine calibration will be described with reference to FIG. When the user turns on the power switch 11, power is supplied to the engine controller 4, the printer controller 3, and the operation panel 12 that are configured in the printer 1. When the power is supplied to the engine controller 4, the microcontroller 9 performs a predetermined printer starting operation according to a predetermined starting sequence. For example, the presence / absence detection of the residual paper in the apparatus, the failure detection of each actuator or sensor, the cleaning operation of the electrostatic adsorption conveyance belt 29, and the like are performed. Since the image forming apparatus of this embodiment includes the environment sensor 5, the temperature and humidity of the surrounding environment are also detected. Thereafter, the microcontroller 9 performs the above-described engine calibration in order to correct image density differences and color misregistration caused by printer body differences, cartridge differences, changes over time, temperature differences, humidity differences, and the like.

  In many cases, the engine calibration is basically required when the power is turned on. In other cases, the engine calibration is also required, for example, when the cartridge is replaced or after a predetermined number of prints are executed. When such a factor that requires engine calibration occurs, the printer engine 2 transmits a calibration request command to the printer controller 3. The printer controller 3 receives the calibration request transmitted from the engine controller 9 and returns a calibration execution command to the engine controller 4 to actually execute the engine calibration.

  Therefore, for example, in the printer controller 3 incorporating a battery or the like, it was determined that the low voltage power supply off / on time was shorter than the predetermined time, the power supply was turned off / on in a short cycle from the previous engine calibration, and the engine calibration was unnecessary. In some cases, engine calibration may be skipped because the printer controller 3 does not transmit a calibration execution command.

  Further, even when the printer controller 3 does not constitute a battery, the fixing device thermistor 7 is used to detect the fixing temperature to detect whether or not the time from power-off to on is a short cycle. If the temperature of the fixing device thermistor 7 at that time is equal to or higher than a predetermined value, the calibration may be skipped. As a result, the startup time of the color image forming apparatus by engine calibration is shortened.

(Pending calibration due to environmental temperature)
Regarding the image forming apparatus according to the first exemplary embodiment, the suspension of engine calibration will be described in detail with reference to FIGS. 1 and 2.

  First, an outline of the operation will be described. The image forming apparatus according to the first embodiment holds or skips the engine calibration under a low temperature environment (for example, less than 7 degrees Celsius). Further, when the environmental temperature rises thereafter, the time after the predetermined temperature rise (for example, 2 hours) is measured, and the engine calibration that has been suspended or skipped after the lapse of the predetermined time is performed. The two hours exemplified here indicate the time required for the internal temperature of the printer to rise even when the room temperature at which the image forming apparatus is installed rises.

  On the other hand, the image forming apparatus consumes electric power every time printing is performed, and the loss amount excluding the exhaust amount of heat increases the internal temperature of the printer. For this reason, for example, the measurement time of 2 hours described above can be shortened by a predetermined ratio every time one page is printed.

  Note that the environmental sensor described in this embodiment is described as measuring the external temperature at which the image forming apparatus is installed. However, as long as the temperature of the cleaning blade can be calculated indirectly, image formation is performed. You may measure the internal temperature of an apparatus.

  FIG. 2 shows an engine calibration state transition table in the first embodiment. The vertical axis shows the row of each event, and the horizontal axis shows the column of each state. Events include temperature changes (events 0 to 2), generation of calibration requests (event 3), timeout of the hold timer (event 4), 1-page printing (event 5), and execution of calibration (event 6). To do.

  In this embodiment, the “temperature change” event is divided into three categories. However, it is not limited to three, and the temperature need not be limited to those shown in FIGS. The first segment of temperature change is event 0 below 7 degrees Celsius, the second segment is event 1 at 7 degrees Celsius or more and less than 10 degrees Celsius, and the third segment is Event 2 at 10 degrees Celsius or more. This temperature change is detected by the environmental sensor 5 and the microcontroller 9 shown in FIG.

  Event 3 of “generation of calibration request” is detected by the microcontroller 9 configured in the engine controller 4 and notified to the printer controller 3. Specifically, when the low-voltage power supply 6 is turned on, when a cartridge is replaced, when a return operation from the sleep mode is performed, an event 3 “generation of calibration request” occurs.

  The “hold timer timeout” event 4 is an event that occurs when a predetermined time elapses after the measurement of the timer 10 built in the microcontroller 9 is started.

  Event 5 of “1-page printing” is an event that occurs when the printer 1 executes printing for one page.

  The “Calibration execution” event 6 mainly occurs when the printer controller 3 transmits a calibration execution command to the engine controller 4 in response to a calibration request notified from the engine controller 4 to the printer controller 3. It is an event. Even when the user requests the printer controller 3 to forcibly execute engine calibration via the operation panel 12, the printer controller 3 transmits a calibration execution command to the engine controller 4, and event 6 is displayed. appear.

  Next, a description will be given using the state transition diagram shown in FIG. State A is an initial state in which the printer is turned off. When the low-voltage power supply is turned on, the state transitions to any one of states 0 to 2 according to the environmental temperature. When the temperature is less than 7 degrees Celsius, the state transits to 0. When the temperature is not less than 7 degrees Celsius and less than 10 degrees Celsius, the state 1 is transited. When the temperature is 10 degrees Celsius or higher, the state transits to 2. In the state 0, when an event 1 of temperature change (7 ° C. ≦ Tc <10 ° C.) occurs, there is no action and the state 1 is transited. In state 1, when event 2 of temperature change (Tc ≧ 10 ° C.) occurs, there is no action and transition to state 2 occurs. On the other hand, if event 0 of temperature change (Tc <7 ° C.) occurs in state 1, there is no action and transition to state 0 occurs. In state 2, when event 1 of temperature change (7 ° C. ≦ Tc <10 ° C.) occurs, there is no action and the state 1 is entered.

  In the state 0, when the event 2 of the temperature change (Tc ≧ 10 ° C.) occurs without going through the event 1 of the temperature change (7 ° C. ≦ Tc <10 ° C.), there is no action and the state 2 is transited. Conversely, in state 2, if event 0 of temperature change (Tc <7 ° C.) occurs without going through event 1 of temperature change (7 ° C. ≦ Tc <10 ° C.), no action is taken and transition is made to state 0 To do.

  In the state 1 and the state 2, when an event 3 of “calibration request” occurs, a calibration request command is transmitted to the printer controller 3 and a calibration operation equivalent to the conventional one is performed. On the other hand, in the state 0, when the event 3 of “Calibration request” occurs, the calibration is suspended and a predetermined initial value is set in the suspension timer, and the state transitions to the state 3.

  In state 3, even if event 3 of “calibration request” occurs, the holding of the calibration request is continued. If event 1 with a temperature change (7 degrees Celsius or more and less than 10 degrees Celsius) occurs, there is no action and the state 4 is transitioned to. In state 4, when event 0 of temperature change (Tc <7 ° C.) occurs, a predetermined initial value is set in the hold timer and the state transitions to state 3. In the state 4, similarly to the state 3, even when the “calibration request” event 3 occurs, the hold of the calibration is continued. In the state 4, when the event 2 of the temperature change (Tc ≧ 10 ° C.) occurs, the measurement of the hold timer is started and the state is changed to the state 5. When an event of temperature change (7 ° C. ≦ Tc <10 ° C.) occurs in state 5, the suspension timer that has started measurement is stopped and transition to state 4 is made. When event 2 of temperature change (10 degrees Celsius or more) occurs, measurement of the hold timer is started and a transition is made to state 5. This means that a temperature of less than 7 degrees Celsius is measured when the power is turned on, a subsequent increase in the environmental temperature is detected, and the internal temperature of the image forming apparatus starts to rise.

  In the state 3, when the event 2 of the temperature change (Tc ≧ 10 ° C.) occurs without going through the event 1 of the temperature change (7 ° C. ≦ Tc <10 ° C.), the measurement of the holding timer is started and the state 5 Transition to. On the other hand, if event 0 of temperature change (Tc <7 ° C.) occurs without going through event 1 of temperature change (7 ° C. ≦ Tc <10 ° C.) in state 5, a predetermined initial value is set in the hold timer. Is set and the state 3 is entered.

  In state 5, even when event 3 of “calibration request” occurs, the calibration request is suspended and the state is maintained without transition. When event 5 of “one page print” occurs, the hold timer is rotated quickly and the state is maintained without transition.

  In state 5, when event 4 of “hold timer time-out” occurs, a temperature of less than 7 degrees Celsius is measured when the power is turned on, and the internal temperature of the image forming apparatus as the environmental temperature subsequently increases is also a predetermined temperature. This means that the above has been reached, and a calibration request command is transmitted to the printer controller 3.

  In the state 3, the state 4, and the state 5, when the operation panel 12 requests the forced execution of the calibration, the printer controller 3 transmits a calibration execution command to the engine controller 4, and “ Event 6 “Calibration execution” may occur. In this case, state 3, state 4, and state 5 transition to state 0, state 1, and state 2, respectively, while clearing the hold timer and the calibration request.

  When event 6 of “Calibration execution” occurs in state 0, state 1 and state 2, state 0, state 1 and state 2 clear the calibration request and state 0, state 1 and state respectively. 2 is maintained.

  That is, based on the state transition diagram of FIG. 1 described above, the engine calibration can be suspended or skipped at a temperature lower than a predetermined low temperature environment, and image formation is performed as the environmental temperature subsequently increases. When the internal temperature of the apparatus rises above a predetermined level, the engine calibration that has been suspended or skipped can be appropriately executed. As a result, it is possible to avoid the recovery cleaning of the test toner pattern required at the time of engine calibration in a low temperature environment, and it is possible to reduce the cleaning failure that easily occurs in the low temperature environment.

  Embodiment 2 of the present invention will be described in detail with reference to the drawings.

  The image forming apparatus according to the second exemplary embodiment detects the environmental temperature of the image forming apparatus using an environmental sensor. When the temperature is equal to or lower than a predetermined temperature, the size or quantity of the toner pattern for performing density detection or color shift detection is determined. The engine calibration is performed with a minimum control. Since the image forming apparatus, the color misregistration correction apparatus, and the image density control apparatus described in the first embodiment have the same contents, description thereof is omitted.

  The material of the electrostatic adsorption conveyance belt 29 in the color image forming apparatus of the present invention is formed of, for example, a PVDF resin containing carbon and is in a transparent state with a slight blackishness. A resist detection pattern image (hereinafter abbreviated as a registration pattern) for detecting an image position and a color shift formed on each photosensitive drum, and a density detection pattern for detecting an image density on the surface of the electrostatic attraction conveyance belt 29. An image (hereinafter abbreviated as a dark patch) is directly transferred. In each of the four color image forming units of black, yellow, magenta, and cyan, a plurality of registration patterns and dark patches are formed on the electrostatic adsorption conveyance belt 29 at predetermined intervals along the traveling direction of the electrostatic adsorption conveyance belt 29. It is formed all around. FIG. 7 shows a resist pattern of the color misregistration correction apparatus in the second embodiment.

  Patterns 17H and 17L shown in FIG. 7 show an example of a registration pattern used for color shift detection. Patches 18H and 18L shown in FIG. 8 show an example of a deep test patch used for density detection. Such a registration pattern and a dark patch are formed on the surface of the electrostatic attraction conveyance belt 29 at predetermined intervals for each basic pattern block of black, yellow, magenta, and cyan.

  When the temperature detected by the engine controller 4 and the environmental sensor 5 shown in FIG. 3 is equal to or higher than a predetermined temperature (for example, 7 degrees Celsius or higher), the registration pattern 17H and the dark patch 18H 29 shows a test pattern drawn on the surface. One registration pattern 17L and dark detection patch 18L indicate test patterns drawn on the surface of the electrostatic adsorption conveyance belt 29 when the detected temperature is less than a predetermined temperature (for example, less than 7 degrees Celsius). It is a thing.

  A sensor (hereinafter, abbreviated as a dark detection register sensor) 16 composed of a light emitting element and a light receiving element is provided at a position facing the electrostatic adsorption conveyance belt 29 on which the registration pattern and the dark detection patch are transferred to the surface. The registration pattern and the dark patch are detected by sampling.

  The detected registration pattern position signal is input to the microcontroller 9 shown in FIG. 3, and the interval between the registration patterns of each color is calculated. The microcontroller 9 corrects the image forming portion and the image formation timing of each color so that the calculated registration pattern interval between each color becomes equal to a predetermined reference value. The color misregistration correction value of each color image obtained in this way is stored in a nonvolatile memory (not shown) configured by the microcontroller 9 as an engine controller.

  On the other hand, the detected density signal of the dark patch is input to the microcontroller 9, and the density of each dark patch is detected. The density of the dark detection patch is detected by the amount of light incident on the light receiving element of the dark detection registration sensor 16, and is determined by the reflectance of the electrostatic adsorption conveyance belt 29 as a base and the toner amount of the dark detection patch as a test pattern image. Is done.

  The density signal of the darkness detection patch detected by the darkness detection sensor 16 is input to the microcontroller 9, and the density of each darkness detection patch is detected.

  Here, a registration pattern that is selectively changed under normal temperature and low temperature environments will be described.

  The registration pattern 17H in FIG. 7 is a pattern used in a relatively warm temperature region where the cleaning blade is hard to be cured, and is a pattern that places importance on detection correction accuracy. The registration pattern 17L is a pattern that is used in a low temperature range where the cleaning blade is relatively hard to cure, and is used as a test pattern so that no cleaning failure occurs during toner collection performed after engine calibration. The amount of toner to be reduced is reduced as much as possible.

  The length of the registration pattern 17H in the direction perpendicular to the conveyance direction of the electrostatic adsorption conveyance belt 29 is determined in consideration of variations in the mechanical arrangement of the electrostatic adsorption conveyance belt 29 and the dark detection registration sensor 16 in the image forming apparatus. The pattern length is sufficiently considered. Further, eight identical registration patterns of the same color are repeatedly formed in the transport direction, and the detection accuracy is improved by calculating the detection average value of the registration patterns. For the detection value averaging, the remaining six detection values excluding the maximum and minimum values are used. Further, by ensuring a sufficiently high density of the registration pattern, a difference in light reflectance between the surface of the electrostatic adsorption conveyance belt 29 and the registration pattern surface is reliably ensured, and measurement accuracy is improved.

  On the other hand, regarding the registration pattern 17L, the length of the registration pattern in the direction orthogonal to the conveyance direction of the electrostatic attraction conveyance belt 29 is shortened to the minimum pattern length, thereby reducing the amount of test toner. Further, in the transport direction, the same registration pattern of the same color is formed with a reduced quantity of about four to reduce the amount of test toner. Further, by reducing the density of the registration pattern to the minimum, the amount of test toner is reduced. For the detection of the registration pattern 17L, an average value of the detected values is calculated after performing a filtering process by firmware such as removing an unexpected detection value due to a detection failure or the like.

  Therefore, as described above, it is possible to execute color misregistration correction control in which a registration pattern in which priority is given to reducing the amount of toner used as much as possible can be selected under a low temperature environment.

  Next, the deep detection patch that is selectively changed under normal temperature and low temperature environments will be described.

  The dark test patch 18H in FIG. 8 is a pattern used in a relatively warm temperature region in which the cleaning blade is hard to be cured, and is a pattern in which detection correction accuracy is emphasized. The dark test patch 18L is a pattern used in a low temperature region where the cleaning blade is relatively hard to be cured, and is used as a test pattern so that a cleaning failure does not occur when the toner is collected after engine calibration. The amount of toner to be reduced is reduced as much as possible.

  The length of the dark detection pattern 18H in the direction perpendicular to the conveyance direction of the electrostatic adsorption conveyance belt 29 is sufficient in consideration of variations in the mechanical arrangement of the adsorption conveyance belt 29 and the dark detection registration sensor 16 in the image forming apparatus. The pattern length is taken into consideration. Further, in the transport direction, while sequentially changing the development bias value, five dark test patterns of the same color are repeatedly formed in succession to form dark test patches for each development bias value. Note that the developing bias value is switched in the arrow section a in the figure.

  FIG. 8Hb is an enlarged view of the dark test patch 18H shown in FIG. 8Ha. Eight black circles in the center of the patch indicate points sampled by the dark detection register sensor 16. FIG. In each dark patch, the detection accuracy is increased by calculating the respective detection average value.

  On the other hand, regarding the dark test patch 18L, the length of the dark test patch in the direction perpendicular to the transport direction of the electrostatic adsorption transport belt 29 is shortened to the minimum pattern length to reduce the amount of test toner. . Also in the transport direction, as shown in FIG. 8Lb, the number of times of sampling within one dark patch is reduced to four, thereby reducing the amount of test toner. . For the detection of the dark patch 8Lb, after performing a filtering process by firmware such as removing an unexpected detection value, an average value of the detected values is calculated. Further, FIG. 8Lc is obtained by deleting unnecessary corner portions of the patch in order to further reduce the area of the dark patch.

  Therefore, as described above, in a low temperature environment, it is possible to execute image density control capable of selecting a dark patch that gives priority to reducing the amount of toner to be used as much as possible.

  As described above, in a predetermined low-temperature environment, a pattern with a reduced amount of test toner used for engine calibration is selected, so the amount of toner collected after engine calibration is reduced. It becomes possible to reduce. As a result, it is possible to perform simple engine calibration in a low temperature environment and reduce the occurrence of cleaning failure due to the cleaning blade being cured.

  Embodiment 3 of the present invention will be described in detail with reference to the drawings.

  The image forming apparatus according to the third exemplary embodiment detects the environmental temperature of the image forming apparatus using an environmental sensor, and skips the image density control sequence when the temperature is equal to or lower than a predetermined temperature and is recorded in advance in a nonvolatile memory. The image is formed according to the conditions. Note that the image forming apparatus, the image density control apparatus, and the engine calibration portion described in the first and second embodiments have the same contents, and thus the description thereof is omitted.

  First, image density control by maximum density control and halftone gradation control when performing multi-value image formation in the color image forming apparatus of this embodiment will be described.

  When multi-value image formation such as full color is performed, the relationship between the input density level signal and the actual image density is linear (density linearity), and for signals of the same density level. The density at which an image is formed needs to be constant (constant density) regardless of conditions such as temperature and humidity. In the case of a full-color image forming apparatus, linearity and uniformity of density are required for four colors, for example, magenta, cyan, yellow, and black.

  However, in an image forming apparatus that performs electrophotographic image forming processing, toner characteristics and development characteristics fluctuate depending on various conditions such as the use environment and the number of prints, so that linearity and uniformity of density are maintained. Therefore, image density control such as maximum density control and halftone gradation control is performed.

  In the maximum density control, a toner image for detection of the maximum density (reference image pattern; dark patch) is experimentally tested for each color toner on a carrier carrying a toner image such as a photosensitive drum or an electrostatic adsorption conveyance belt. The density detection result is created and fed back to process conditions such as a developing bias potential, and the maximum density of each toner is adjusted to a predetermined value.

  Halftone gradation control creates a plurality of halftone (halftone gradation) patches for each color toner on a carrier such as a photosensitive member or a transfer member, and detects their density with an optical sensor or the like. From the result, a look-up table (hereinafter also referred to as “LUT”) is corrected (so-called γ correction) in the controller so that the input image signal and the output image density have a linear relationship. As described above, by performing the γ correction after controlling the maximum density to a predetermined value, the linearity and the constant density are maintained.

  FIG. 9 shows a flowchart of image density control in the third embodiment.

  The image density control according to the present embodiment is performed by updating processing parameters in the output γ correction processing or the like by the printer controller 3. Specifically, each of the above processes is performed using a lookup table, and image density control is performed by updating the table data. In order to update the table data, a predetermined image (for example, a dark patch) is output by an image forming apparatus that is an object of image density control, and this is optically read. After the process, information is transmitted to the printer controller 3 (step S209 in FIG. 9).

  On the other hand, in a low temperature environment, the hardness of the cleaning blade is increased and there is a risk that cleaning failure may occur. Therefore, in the image forming apparatus of this embodiment, the sequence of skipping image density control and generating toner recovery is avoided. The procedure will be described below.

  The image forming apparatus basically requires engine calibration after the low-voltage power supply is turned on to correct image density differences caused by machine differences, cartridge differences, changes over time, temperature differences, humidity differences, etc. There are many cases.

  Therefore, in step S101, it is determined whether or not engine calibration is requested when an event such as power-on occurs. For example, when the printer controller 3 shown in FIG. 3 incorporating a battery or the like is used, the low-voltage power supply OFF / ON time is shorter than a predetermined time, and the power supply is turned OFF / ON in a short cycle since the previous engine calibration. Therefore, it is determined that engine calibration is unnecessary. Further, when the temperature of the fixing device 13 is detected by using the fixing device thermistor 7 or the like, and it is detected that the time from power-off to on is a short cycle, it is determined that the engine calibration is unnecessary.

  On the other hand, if the low-voltage power supply is in a state other than the above, it is determined that engine calibration is necessary, and the process proceeds to step 102. If it is detected that a predetermined time or a predetermined number of prints have elapsed since the previous engine calibration, it is determined that the engine calibration is necessary, and the process proceeds to step S102.

  In step S102, the ambient temperature is detected, and if it is 7 degrees Celsius or more, the process proceeds to step S201 and maximum density control (Dmax control) is started. If it is less than 7 degrees Celsius, the process proceeds to step S301. In this embodiment, the threshold value of the low temperature environment where the cleaning failure occurs is set as an example of 7 degrees Celsius. However, the temperature need not be limited to this value as long as the temperature is related to the cleaning failure.

  Next, steps S201 to S210 where the maximum density control is started will be described. When the maximum density control is started, a cleaning sequence is first executed in step S201 to clean the electrostatic attraction conveyance belt and the like. In step S202, a dark patch for maximum density control is formed under the density detection sensor on the surface of the electrostatic adsorption transport belt 29 while changing the developing bias value. In step S203, a density detection sensor is used to detect a dark patch. In step S204, based on the output of the density detection sensor, a developing bias value at which the density is appropriate is calculated by the microcontroller. In step S205, the developing bias value calculated by the microcontroller is set. In step S206, the concentration patch used for the maximum density control (Dmax control) is collected and cleaned, and the maximum density control ends. Next, halftone gradation control is started following maximum density control.

  In step S207, a halftone halftone image signal is generated, and a dark patch is created on the photosensitive drum in accordance with this signal. In the present embodiment, each color image signal has 8 bits, and can generate image signals of 256 levels from 00H to FFH (H means hexadecimal display). However, a latent image of the patch is formed by generating image signals of about 10 levels such as 00H, 10H,... A halftone image for halftone gradation control is formed on the surface of the electrostatic attraction / conveyance belt so as to be under the density detection sensor as in the case of maximum density control. In step S208, the density of the halftone image is measured using a density detection sensor. In step S209, the output signal of the density detection sensor is converted into density information by the density conversion table and transmitted to the printer controller. In step S210, the dark patch used for the halftone gradation control is collected and cleaned, and the halftone gradation control ends. As described above, when the environmental temperature is 7 degrees Celsius or higher, image density control is executed.

  Next, a case where the environmental temperature is less than 7 degrees in step S102 and the process proceeds to step S301 will be described. In step S301, a development bias value suitable for a low temperature environment stored in advance is read from a nonvolatile memory or the like configured in the engine controller. In step S302, the read development bias value is set. In step S303, density information suitable for the low temperature environment is transmitted to the printer controller. Then, the printer controller updates the data in the lookup table, and the setting under the simple low temperature environment is completed.

  Therefore, as described above, in steps S301 to S303 in a low-temperature environment, although the engine calibration is suspended or skipped, it is possible to set the development bias and the LUT based on information stored in advance. . As a result, in a low temperature environment where the cleaning blade is cured, a simple development bias value and lookup table can be set, and cleaning defects occurring after engine calibration can be reduced.

State transition diagram of engine calibration showing the first embodiment of the present invention Engine calibration state transition table showing the first embodiment of the present invention The figure which shows the schematic block of the control circuit in the Example of this invention Cross-sectional explanatory diagram showing an overview of the overall configuration of the image forming apparatus Cross-sectional explanatory view showing a schematic configuration of a process cartridge of the image forming apparatus Schematic configuration diagram of a cleaning blade of an image forming apparatus (A) and (b) are diagrams showing examples of a registration pattern in a normal environment and a low-temperature environment in the second embodiment of the present invention. (A) and (b) are diagrams showing an example of a dark detection patch in a normal environment and a low temperature environment in the second embodiment of the present invention. Flowchart of image density control in the third embodiment of the present invention

Explanation of symbols

1 Printer (corresponds to one of the configurations related to calibration)
2 Printer engine (corresponds to one of the configurations related to calibration)
3. Printer controller (supports the function to send calibration execution commands to the microcontroller)
4 Engine controller (supports the function to send calibration request command from microcontroller)
5 Environmental sensor (corresponding to temperature detection means)
6 Low voltage power supply 7 Fixing device thermistor 8 Cartridge 9 Microcontroller (corresponding to temperature discrimination means)
DESCRIPTION OF SYMBOLS 10 Timer 11 Power switch 12 Operation panel 13 Fixing device 14 Fixing driven roller 15 Fixing pressure roller 16 Dark detection register sensor 17 Registration pattern 18 Dark detection patch 23 Charging roller 24 Developing device (corresponding to developing means)
25 Cleaning device (corresponding to cleaning means)
26 Nonvolatile memory element 29 Electrostatic adsorption conveyance belt (corresponding to conveyance means)
31 Photosensitive drum (corresponding to image carrier)
32 Transfer roller 33 Development roller 35 Laser scanner device 36 Adsorption roller 37 Registration roller 41 Toner 43 Toner supply roller 44 Development blade 51 Cleaning blade

Claims (11)

At least one image carrier that is rotationally driven, developing means for developing the latent image on the image carrier and visualizing it as a toner image, and transport for carrying and transporting the recording material or the directly formed toner image A plurality of image forming units that form a toner image on the recording material or on the transport unit arranged along the transport direction of the transport unit, and a cleaning that cleans the image carrier and the transport unit An image forming apparatus comprising:
Temperature detecting means for detecting temperature; and temperature determining means for determining whether or not the temperature detected by the temperature detecting means is equal to or lower than a set value temperature. An image forming apparatus comprising: means for suspending or skipping execution of calibration for forming a test toner pattern on the conveying means when it is determined that   The image forming apparatus according to claim 1, wherein the temperature detecting unit detects a temperature of the cleaning unit.   The image forming apparatus according to claim 1, wherein the temperature detecting unit detects an ambient temperature or an internal temperature of the image forming apparatus.   The image forming apparatus according to claim 1, wherein the toner pattern forms an image density or an image color resist for detection and correction.   The image forming apparatus according to claim 1, wherein the calibration that has been suspended or skipped is executed after a set standby time after the temperature detecting unit detects an increase from a set temperature.   6. The image forming apparatus according to claim 5, wherein the waiting time is a time from when the ambient temperature or the internal temperature rises until the temperature of the cleaning unit rises to the same temperature.   6. The image forming apparatus according to claim 5, wherein the waiting time is shortened by a predetermined ratio according to execution of printing. At least one image carrier that is rotationally driven, developing means for developing the latent image on the image carrier and visualizing it as a toner image, and transport for carrying and transporting the recording material or the directly formed toner image A plurality of image forming units that form a toner image on the recording material or on the transport unit arranged along the transport direction of the transport unit, and a cleaning that cleans the image carrier and the transport unit An image forming apparatus comprising:
Temperature detecting means for detecting temperature, temperature determining means for determining whether or not the temperature detected by the temperature detecting means is equal to or lower than a set value temperature, and calibration for detecting and correcting image density or color resist of the image And
When the temperature determining means determines that the temperature is equal to or lower than a set value, the calibration is performed by forming a test toner pattern formed on the conveying means that is smaller or less than the time when the temperature is higher than the set value. An image forming apparatus that calculates parameters related to image formation by executing.   The image forming apparatus according to claim 8, wherein the temperature detecting unit detects an ambient temperature or an internal temperature of the image forming apparatus. At least one image carrier that is rotationally driven, developing means for developing the latent image on the image carrier and visualizing it as a toner image, and transport for carrying and transporting the recording material or the directly formed toner image A plurality of image forming units that form a toner image on the recording material or on the transport unit arranged along the transport direction of the transport unit, and a cleaning that cleans the image carrier and the transport unit An image forming apparatus comprising:
Temperature detecting means for detecting temperature; and temperature determining means for determining whether or not the temperature detected by the temperature detecting means is equal to or lower than a set value temperature. If it is determined, the parameter related to image formation is calculated according to the information stored in the memory element, and the execution of the calibration for forming the test toner pattern on the conveying means is suspended or skipped. An image forming apparatus.   The image forming apparatus according to claim 10, wherein the temperature detecting unit detects an ambient temperature or an internal temperature of the image forming apparatus.