JP5459473B2 - Paper feeding device and image forming apparatus - Google Patents

Description

  The present invention relates to a sheet feeding device and an image forming apparatus equipped with the sheet feeding device.

  For example, in an electrophotographic image forming apparatus, a fixing temperature used as a fixing condition, a sheet conveyance speed, and the like are important factors for improving image quality and speed. Therefore, a technique for controlling the set temperature, fixing speed, or fixing pressure of the fixing device, which detects the heat capacity of the sheet for improving the fixing property and depends on the detected temperature level, is already known. For example, in Patent Document 1, for the purpose of avoiding fixing failure due to the type of paper, the heat capacity of the paper is detected by the heat capacity detecting means installed in the paper transport path, and the set temperature of the fixing device and the fixing are determined based on the information. A configuration for controlling at least one of speed and fixing pressure is disclosed. However, in the image forming apparatus provided with the conventional heat capacity detecting means, the heat capacity of the paper is detected by the heat capacity detecting means installed in the paper conveyance path, and the set temperature, fixing speed or fixing pressure of the fixing device is determined based on the information. Had controlled at least one of them. The heat capacity detection element configured by the heating element and the temperature detection element measures the heat capacity of the paper by detecting the temperature change of the heating element, which changes depending on the amount of heat energy taken by the paper from the heating element. In addition, since the heat capacity is measured and transported to the fixing device while the paper is being transported, there is a problem that fixing failure occurs when the paper reaches the fixing unit before the fixing device is controlled and the state is optimal for fixing. It was. Also in Patent Document 1, before the fixing device is controlled to shift to an optimum state for fixing, there is a possibility that the sheet reaches the fixing unit and fixing failure occurs.

  Japanese Patent Application Laid-Open No. 2005-228561 describes a fixing control device that includes a temperature / humidity sensor 24 in a paper tray and sets an optimum fixing temperature corresponding to the temperature / humidity of the paper tray using a neuronetwork. However, there is a problem that a fixing failure occurs when the sheet reaches the fixing unit before the fixing device is controlled and the state is optimal for fixing. If the paper conveyance speed is reduced to avoid this, the productivity of image formation decreases.

  The paper feeding device described in Patent Document 3 includes a heater 30 at the bottom of the paper feeding tray, and water content sensors S1 and S2 at the top of the paper feeding tray to control dehumidification by the heater according to the water content state of the paper. To do. However, this control causes the paper temperature to change depending on the moisture content of the paper. For example, when the temperature is relatively high and humid, the paper is heated to a high temperature, and when the temperature is relatively low and low, the paper is heated. Does not heat and stays at a low temperature. This causes over and under fixing.

  In Patent Document 4, a heater is provided in a plurality of stages in a paper feed tray, a humidity sensor is provided inside or outside the image forming apparatus to control the humidity of the paper feed unit, and heat supply or convection is used. A paper dehumidifier that controls the temperature of the entire paper section is described. However, in this case as well, the paper temperature changes depending on the water content of the paper. For example, when the temperature is relatively high and high, the paper is heated and becomes high, and when the temperature is relatively low and low, the paper is heated. Does not heat and stays at a low temperature. This causes over and under fixing.

  In the case of an ink jet recording apparatus, the ink absorption characteristics of the recording paper and the drying speed of the recording ink are also affected by the temperature of the recording paper, and the optimum image forming speed varies. Changes in the recording paper temperature during image formation cause variations in print quality. In the case of a thermal recording apparatus, over and under coloring occurs due to the paper temperature fed to the thermal recording head.

  SUMMARY OF THE INVENTION A first object of the present invention is to provide a sheet feeding device that feeds recording paper having a temperature suitable for image formation and an image forming apparatus equipped with the sheet feeding device. A second object is to prevent over- and under-fixing.

(1) Paper feed tray (28a, 28b);
Feeding means (28af, 28bf) for feeding and feeding the recording paper on the paper feed tray;
Heating means (29a, 29b) provided on the bottom plate of the paper feed tray ;
Temperature detecting means (30a, 30b) for detecting the temperature (Ta) of the upper space of the recording paper on the paper feed tray when the operation power is turned on;
When the temperature (Ta) is lower than the first set temperature (Ts1), heating is started using the heating means, and when the temperature reaches the second set temperature (Ts1 / Ts2) equal to or higher than the first set temperature, the heating is stopped or When the temperature is lowered and the temperature (Ta) is lower than the first set temperature (Ts1), the feeding of the recording paper by the feeding means is suspended and the recording by the feeding means is performed at a temperature equal to or higher than the first set temperature (Ts1). Recording paper feed control means (51) for feeding paper;
A paper feeder (27) comprising:

  In addition, in order to facilitate understanding, the reference numerals or corresponding matters of corresponding elements or equivalent matters of the embodiments shown in the drawings and described later are added in parentheses for reference. The same applies to the following.

Temperature above the space of the recording paper on the paper feed tray (Ta) is without performing sheet feeding is less than the first set temperature (Ts1), the heating means (29a, 29b) warming the recording paper on the paper feed tray by Since the sheet feeding is started after being heated to the first set temperature (Ts1) or higher, it is possible to supply a recording sheet in a state suitable for high quality and stable image formation.

  In the electrophotographic image forming apparatus equipped with the paper feeding device (27), over and under fixing can be prevented. Further, in the case of an ink jet recording apparatus equipped with this paper feeding device (27), the optimum image forming speed can be set to be substantially constant, and the printing quality can be stabilized. In the case of a thermal recording apparatus equipped with this paper feeding device (27), it is possible to eliminate color variation (excess or deficiency).

FIG. 3 is a longitudinal sectional view showing an outline of the mechanism of the multifunction copying machine MF1 equipped with the sheet feeding device 27 of the first embodiment of the present invention. FIG. 2 is a block diagram showing an outline of a configuration of an image data processing system of the multi-function copying machine MF1 shown in FIG. 3 is a flowchart showing an outline (first embodiment) of temperature control in a sheet feeding device 27 by an engine ASIC 51 (CPU 52 in the engine) shown in FIG. 6 is a flowchart illustrating a second embodiment of temperature control in the paper feeding device 27; 10 is a flowchart illustrating a third embodiment of temperature control in the paper feeding device 27; It is a flowchart which shows the content of the interruption process INTA set by step s14c of FIG. 10 is a flowchart illustrating a main part of a fourth embodiment of temperature control in the paper feeding device 27;

  (2) The recording paper feeding control means (51) feeds the recording paper by the feeding means when the temperature (Ta) is lower than the first set temperature (Ts1) when the paper temperature adjustment is designated. Is held and the recording paper is fed by the feeding means at a temperature equal to or higher than the first set temperature (Ts1). When there is no paper temperature adjustment designation, the recording paper by the feeding means is irrelevant to the temperature (Ta). The sheet feeding device according to (1) above. According to this, the user can designate paper temperature adjustment and perform image recording with high image quality. Further, it is possible to record an image quickly without specifying the paper temperature adjustment even if the image quality is not high.

  (3) The recording paper feeding control means (51) issues a waiting notification while the feeding of the recording paper is suspended; the paper feeding device according to (1) or (2). According to this, the user can understand the reason why the recording paper feeding is not started from the waiting notification.

  (4) The recording paper feed control means (51) derives and notifies the waiting time (Wt) until the temperature reaches the first set temperature (Ts1) or more while the feeding of the recording paper is suspended. A sheet feeding device according to any one of (1) to (3) above; According to this, the user can recognize the waiting time until the start of feeding, that is, how long to wait.

  (5) The second set temperature (Ts2) is the same as the first set temperature (Ts1) (FIG. 3); the sheet feeding device according to any one of (1) to (4) above. According to this, since heating by the heating means (29a, 29b) is started at a temperature lower than the first set temperature (Ts1) and heating is stopped at a temperature higher than the first set temperature (Ts1), the heating means (29a, 29b) is stopped. Repeated heating and stopping according to 29b). When the control period (Hs) for heating and stopping by the heating means (29a, 29b) with reference to the detected temperature (Ta) of the temperature detection means (30a, 30b) is relatively long, the heating means (29a, This embodiment is preferable because the repetition of heating and stopping in 29b) becomes less than the control cycle (Hs).

  (6) The second preset temperature (Ts2) is higher than the first preset temperature (Ts1) (FIGS. 4 and 5); the sheet feeder according to any one of (1) to (4) above. According to this, heating by the heating means (29a, 29b) is started at a temperature lower than the first set temperature (Ts1), and is heated at a temperature higher than the second set temperature (Ts2) higher than the first set temperature (Ts1). Since it is stopped, the repetition of heating and stopping by the heating means (29a, 29b) is infrequent. When the control period (Hs) for heating and stopping by the heating means (29a, 29b) with reference to the detected temperature (Ta) of the temperature detection means (30a, 30b) is relatively short, this control period (Hs This embodiment is preferable because the repetition of frequent heating and stopping due to () is suppressed.

  (7) The recording paper feed control means (51) sets the detected temperature (Ta) of the temperature detecting means (30a, 30b) at a set time period (Hs) while waiting for a paper feed instruction (image forming instruction). For reference, if the temperature is lower than the first set temperature (Ts1), the heating means is used to start heating, and when the temperature reaches the second set temperature (Ts1 / Ts2) equal to or higher than the first set temperature, the heating is stopped or heated. The sheet feeding device according to any one of (1) to (6) above. According to this, in a standby state waiting for a paper feed instruction (image formation instruction), if the recording paper temperature is low, heating is performed. Therefore, when the paper supply instruction (image formation instruction) is given, the recording paper is the first. There is a high probability that the temperature is equal to or higher than the set temperature (Ts1), and the waiting time from when a paper feed instruction (image formation instruction) is issued until paper feed is started is shortened.

  (8) The recording paper feed control means (51) reports an abnormality (s32, s33, s42) when the waiting notification duration (Rhp) exceeds a set value (Eh); The sheet feeding device according to any one of (7) to (7) (FIG. 6). The duration (Rhp) is the heating time of the recording paper on the paper feed tray by the heating means (29a, 29b) .If this is abnormally long, the heating means (29a, 29b) or the temperature detection means (30a, There is a risk of failure in 30b). In this case, since the recording paper feed control means (51) notifies the abnormality, it is possible to take measures beforehand.

  (9) The recording paper feed control means (51) starts timekeeping (It) when heating is started using the heating means, and when the heating is continued, the timekeeping value (It) is When the set value (Ehi) or more is reached, an abnormality is notified (s45, s46; s33v, s42); the paper feeding device according to any one of (1) to (7) (FIG. 7). The time measured value (It) is the heating time of the recording paper by the heating means (29a, 29b) while waiting for a paper feed instruction (image forming instruction), and if this is abnormally long, the heating means (29a, 29b) or There is a risk of failure of the temperature detecting means (30a, 30b). In this case, since the recording paper feed control means (51) notifies the abnormality, it is possible to take measures beforehand.

(10) The sheet feeding device (27) according to any one of (1) to (9) above;
Forming an electrostatic latent image on the photosensitive member (22), developing the electrostatic latent image to visualize it, and developing the developed image directly or indirectly via the intermediate transfer member (21), the paper feeding device (27) An electrophotographic image-forming device (20) that transfers to the recording paper fed by
A fixing device (34) for fixing the visible image on the recording paper by heating and pressurizing the recording paper on which the visible image is transferred by the imaging device (20);
An image forming apparatus (FIG. 1).

  According to this, the fixing quality by the fixing device (34) can be improved by using the paper temperature adjusting function of the paper feeding device (27).

  (11) Further, an image reading device (10) that reads an image on a document and generates image data; and converts the image data into recording image data that conforms to the image forming characteristics of the image forming device (20). The image forming apparatus (10) according to (10), further comprising an image data processing means (41) to be given to the image forming apparatus (20). According to this, a document copy with high fixing quality can be obtained.

  (12) The image data processing means (41) further converts the document information given from the outside (PC1, 67, network, 60) into image data for recording and gives it to the image forming device (20); The image forming apparatus according to 11) (FIG. 2). According to this, for example, a document created by a personal computer (PC1) can be printed out with high fixing quality by the image forming apparatus.

  Other objects and features of the present invention will become apparent from the following description of embodiments with reference to the drawings.

Example 1
FIG. 1 shows an outline of a digital full-color copying machine (multifunction copying machine) MF1 having an MFP (Multi Function Printer) function according to the first embodiment of the present invention. This full-color copying machine is roughly constituted by units of an automatic document feeder (ADF) 12, a color scanner 10, a color printer 20, a paper feed bank 27, and an operation board 66 (FIG. 2). . A LAN (Local Area Network) to which the personal computer PC1 is connected is connected to the in-machine network I / F 62 (FIG. 2). The facsimile controller in the machine can also perform facsimile communication via the network I / F 62 modem.

  The printer 20 includes a transfer unit, and the transfer unit includes a transfer belt 21 that is an endless belt. The transfer belt 21 is wound around three support rollers and one tension roller, and is driven to rotate counterclockwise. Near the tension roller, there is a transfer body cleaning unit that removes residual toner remaining on the transfer belt 21 after image transfer.

  The transfer belt 21 between one support roller and another support roller has Bk (black), C (cyan), M (magenta), and Y (yellow) from the upstream side along the moving direction. An image forming unit for each color image is provided, and there is a transfer roller 26 facing each photoconductor drum 22 in the image forming unit with the transfer belt 21 in between. Above the image forming apparatus is an optical writing unit 24 that irradiates each photosensitive drum of each color photosensitive unit with laser light for image formation. The photosensitive drum 22 is uniformly charged by the charging roller 23, and the optical writing unit 24 projects a laser modulated by an image signal onto the charging surface. The electrostatic latent image generated thereby is developed by the developing device 25 into a toner image. This toner image is transferred to the transfer belt 21.

  Below the transfer belt 21 is a conveyance belt 33. The conveyor belt 33 transfers the toner image on the transfer belt 21 onto a recording sheet, that is, a sheet sent out by a sheet feeding bank 27 that is a sheet feeding device. The sheet onto which the toner image has been transferred is sent out to the fixing unit 34 by the conveyor belt 33. Below the conveying belt 33 and the fixing unit 34, there is a double-sided drive unit 35 that is a sheet reversing unit that feeds a sheet immediately after an image is formed on the front surface and reverses the front and back to record an image on the back surface.

  When the start switch of the operation board 66 (FIG. 2) is pressed, if there is a document in the automatic document feeder (ADF) 12, it is transported onto the contact glass of the scanner 10 and then there is no document in the ADF 12. In order to read a manually placed document on the contact glass, the scanner 10 is immediately driven, and the first carriage and the second carriage in the scanner 10 are read and scanned. Then, light is emitted from the light source on the first carriage to the contact glass, and reflected light from the document surface is reflected by the first mirror on the first carriage and directed to the second carriage, and reflected by the mirror on the second carriage. Then, an image is formed on a CCD as a reading sensor through an imaging lens. Bk, C, M, and Y color recording data are generated based on the image signal obtained by the reading sensor.

  Further, when the start switch is pressed, the rotation driving of the transfer belt 21 is started, the image forming preparation of each unit of the image forming apparatus is started, and the image forming sequence of each color image is started. Thus, an exposure laser modulated based on each color recording data is projected onto the photosensitive drum for each color, and each color toner image is transferred onto the transfer belt 21 as a single image by each color image forming process. When the leading edge of the toner image enters the conveying belt 33, the sheet is fed to the transfer belt 33 from the registration roller pair 32, that is, the feeding roller at a timing so that the leading edge enters the conveying belt 33 at the same time. The toner image on the belt 21 is transferred to the paper. A voltage for transferring toner is applied to the transfer belt 21 by a transfer roller 26. The sheet on which the toner image has moved is sent to the fixing unit 34 where the toner image is fixed on the sheet.

  Note that the above-mentioned paper selectively rotates one of the feed rollers 28af and 28bf, which are feeding means, immediately above the feed trays (also referred to as feed stages or cassettes) 28a and 28b of the feed bank 27. The paper is fed from one of the paper feed trays 28a and 28b provided in multiple stages in the paper feed bank 27, separated by a separation roller, and put into a vertically arranged transport roller unit, and transported upward to be stored in the printer 20. The paper is guided to the conveyance path, conveyed to the registration roller pair 32 by the conveyance roller 31 of the conveyance path, and the front end of the sheet is abutted against the registration roller pair 32 and stopped. It is driven and sent to the conveyor belt 33. It is also possible to feed paper by inserting paper on the right side manual feed tray. When the user inserts paper on the manual feed tray, the printer 20 rotates the paper feed roller of the manual feed tray to separate one sheet of paper on the manual feed tray and pull it into the manual feed path. Stop against the pair 32.

  The paper discharged after receiving the fixing process by the fixing unit 34 is guided to a discharge roller by a switching claw and stacked on a paper discharge tray (not shown). Alternatively, it is guided to the double-sided drive unit by the switching claw, reversed there and led again to the transfer position, and the image is recorded also on the back surface, and then discharged onto the paper discharge tray by the discharge roller. On the other hand, residual toner remaining on the transfer belt 21 after image transfer is removed by a transfer body cleaning unit (not shown) to prepare for image formation again.

  The bottom plates of the paper feed trays 28a and 28b are equipped with heaters 29a and 29b, which are heating means, suitable for heating (slow heating), with heater wires embedded in the plates, and loaded on the paper feed trays. The temperature sensors 30a and 30b, which are temperature detection means, detect the temperature of the space above the paper.

  FIG. 2 shows an outline of the image data processing system of the copying machine MF1 shown in FIG. The copying machine MF1 includes a scanner 10 that reads an image on a document as a document reading device, a printer 20 that is an image forming device that writes an image on a sheet, and an engine ASIC (Application Specific IC) 51 that controls these. The engine ASIC 51 includes an engine 50 and is connected to a printer controller 40 that performs system control and image processing control of the copying machine by a general-purpose bus such as a PCI bus. The engine ASIC 51 includes a process controller that controls reading of a document image by the scanner 10 and image formation on a sheet by the printer 20, and the main body of the process controller is a CPU 52. The engine ASIC 51 is also a recording paper feed control unit that controls paper temperature adjustment and paper feed of the paper feed bank 27.

  The printer controller 40 includes a controller ASIC 41, a main CPU 42, a ROM (EEPROM) 43 that stores BIOS, a NAND flash ROM 44 that stores software (programs) and stores a large amount of image data, job history, and the like. There is a RAM 45, a hard disk 46, and an engine I / F 47) that store and hold status information of each part of the copier. Hereinafter, the NAND flash ROM 44 is expressed as FROM 44.

  The I / O controller 60 of the copying machine MF1 is an I / OASIC, and is connected to the printer controller 40 by a general-purpose bus such as a PCI bus different from the general-purpose bus on the engine 50 side. The I / O controller 60 includes a circuit (not shown) that controls the return from the energy saving mode to the normal mode, a sub CPU 61 that controls the main CPU 42 to control communication via the network in the energy saving mode, and a network or USB host. I / F 62, 63, SD I / F 64, operation I / F 65, and the like. A controller unit including the printer controller 40 and the I / O controller 60 performs overall control of the copying system, that is, system control. The main CPU 42 of the printer controller 40 can easily access not only the RAM 45 but also the internal registers in the I / O controller 60.

  SD card 67, which is a removable storage medium and an external storage device, stores optional font data, stores optional application programs, mounts system update programs, stores address book data, For storing user's document information, etc., one of these is attached to and detached from the card reader connected to the SD I / F 64. The USB I / F 63 is connected / separated with a communication cable for connecting a digital camera, a document image scanner, a personal computer PC1 and other HOSTs.

  The controller ASIC 41 exchanges image data between the I / O controller 60 and the engine ASIC 51 of the engine 50 under the control of the main CPU 42. In addition, the controller ASIC 41 is also an image data processing means, and an image data processing function for converting the image data generated by the scanner 10 by reading the document into recording image data suitable for the image forming characteristics of the printer 20 and giving the image data to the printer 20; Also, an image data processing function for converting document information given from outside (PC 1, SD card 67, network) via the I / O controller 60 into image data for recording and giving it to the printer 20 is also provided.

  The operation board 66 is an operation board of the multifunction copy machine MF1. The operation board 66 is provided with a key switch group including an initial setting key and a numeric keypad and a state indicator lamp group in addition to a touch panel which is a flat display capable of touch input. When the initial setting key is operated, an initial setting key is displayed on the touch panel. The setting menu is displayed. When the user designates “paper temperature adjustment” in the initial setting menu by touch or key input, the temperature threshold value Ts1, which becomes the reference paper temperature for designation / cancellation of “paper temperature adjustment” and paper temperature adjustment (second) In the embodiment and later, items for inputting Ts2) and the control period Hs of the waiting paper temperature adjustment waiting for an image forming (paper feed) instruction (and the interruption period HsA in the third and later embodiments) are displayed. Initially, the standard state is displayed, but the user can change the contents of each item by touch or key input.

  The operation voltage is applied to the entire copying machine MF1, and it is possible not only to cope with external access but also to start image processing instructed in response to instructions such as reading, copying, printing, etc., that is, image processing instructions. The state that can be performed is referred to as a normal mode or an operation mode, and a circuit portion and a state for recognizing an external access (external access) such as communication from outside and a print instruction or an operator's operation (operator access) to the copier MF1. A state where power is always supplied only to a circuit that holds information and no power is supplied to other circuit portions is referred to as an energy saving mode (energy saving mode) or a power saving mode (low power consumption mode). In FIG. 2, the operation mode is applied to all of the engine 50, the printer controller 40, and the I / O controller 60 in the normal mode. In the energy saving mode, the operating voltage to the entire engine 50 and to the main CPU 42 and the controller ASIC 41 in the printer controller 40 is cut off.

  In FIG. 3, after the main power switch of the copying machine MF1 is turned on or during the on time, the energy saving mode is switched to the operation mode, and the operation voltage is applied to the engine ASIC 51, and the operation power is turned on. An outline of “paper temperature adjustment” by the engine ASIC 51 is shown. When the engine ASIC 51 is started by “operating power on”, the engine ASIC 51 reads the state of each part in the engine 50 and sets (initializes) the state. When each part is ready (normal operation is possible), the Hs timer is started, that is, the time limit The timing of the value Hs is started (s1), and the detected temperatures Ta and Tb of the temperature sensors 30a and 30b are read (s2).

  When the detected temperatures Ta and Tb are read, if the detected temperature Ta is lower than the set temperature T1 that is shared with the first set temperature and the second set temperature in the first embodiment, the engine ASIC 51 detects The heater 29a is energized (s3, s4), and if it is equal to or higher than the set temperature T1, the heater 29a is deenergized (s5). Similarly, when the detected temperature Tb is lower than the set temperature T1, the heater 29b of the paper feed tray 28b is energized (s6, s7), and when it is higher than the set temperature T1, the heater 29b is deenergized (s8).

  The reading of the detected temperature Ta (Tb) and the energization / energization of the heater 29a (29b) corresponding to the detected temperature are repeated in the Hs cycle (s9, s1). If an image formation instruction (including a print instruction and a copy instruction) is given from the printer controller 40 during this repetition, the engine ASIC 51 designates / cancels “paper temperature adjustment” in the initial setting of the paper temperature adjustment. If this is a release designation, that is, if there is no paper temperature adjustment designation, the process proceeds to image formation (s22), and image formation process control (print process control or copy process control) is performed (s11, s22). However, if the paper temperature adjustment is designated, the paper feed designation is referred to as the paper feed tray 28a or 28b (s12, s16). If the paper feed tray 28a is designated, the detected temperature Ta of the temperature sensor 30a is set to the paper feed tray. When 28b is specified, the detected temperature Tb of the temperature sensor 30b is read (s13, s17), and when any detected temperature is read, if the read temperature Ta (Tb) is equal to or higher than the set temperature Ts1, the corresponding The energization of the heater 29a (29b) of the paper feed tray 28a (28b) is stopped (s14, s20; s18, s20), the process proceeds to image formation (s22), and image formation process control is performed. However, when the read temperature Ta (Tb) is lower than the set temperature Ts1, “Waiting notification” (s15, s19) is displayed on the touch panel of the operation board 66, “Paper temperature rising. Please wait”. That is, “waiting” is displayed, and the heater 29a (29b) is energized (s4, s7). Thereafter, when the detected temperature of the temperature sensor 30a (30b) becomes equal to or higher than the set temperature, the energization of the heater 29a (29b) is stopped (s20), the “waiting” display is canceled (erased) (s21), and the image ( Proceed to s22).

  When the temperature Ta (Tb) becomes equal to or higher than the set temperature Ts1 after the heater 29a (29b) is energized, the energization current value is reduced instead of immediately deenergizing, and then energized after a predetermined time. There is also an aspect of blocking the.

-Example 2-
The engine ASIC 51 of the second embodiment performs the paper temperature adjustment shown in FIG. The difference from the paper temperature adjustment (FIG. 3) of the first embodiment is that the heater 29a (if the second set temperature Ts2 is higher than the first set temperature Ts1 and the detected temperature Ta (Tb) is lower than the first set temperature Ts1. 29b) is energized (s4, s7), but the energization is stopped when the detected temperature Ta (Tb) reaches the second set temperature Ts2 or higher (s5a, 5b; s8a, 8b). Other functions of the paper temperature adjustment of the second embodiment are the same as those of the paper temperature adjustment (FIG. 3) of the first embodiment. The hardware and other functions of the second embodiment are the same as those of the first embodiment (FIGS. 1 to 3).

-Example 3-
The engine ASIC 51 of the third embodiment performs the paper temperature adjustment shown in FIG. In the paper temperature adjustment of the third embodiment, when the image forming instruction is given, if the detected temperature Ta (Tb) of the temperature sensor 30a (30b) is lower than the first set temperature Ts1, “waiting” is notified (s15a , S19a), HsA (HsB) timer HsA (HsB) is started (s15b, s19b), the timer interrupt INTA (INTB) is permitted (s15b, s15c; s19b, s19c), and the heater 29a (29b) Energize (s4, s7). When the detected temperature Ta (Tb) reaches the second set temperature Ts2 or more, the timer interruption is stopped (s20a), the heater energization is stopped (s20b), and the “waiting” display is canceled (erased) (s21). The process proceeds to image formation (s22).

  FIG. 6 shows the contents of the timer interrupt INTA. Since this timer interrupt INTA is executed in response to the timer HsA being timed out, it is repeatedly executed in the HsA cycle (s15b, s31). The contents of the timer interrupt INTB are the same as the contents of INTA. Since the timer interrupt INTB is executed in response to the timer HsB time-over, it is repeatedly executed in the HsB cycle.

  When the process proceeds to the timer interrupt INTA (FIG. 6) in response to the timer HsA time-over, the engine ASIC 51 of the third embodiment first restarts the timer HsA (s31) and permits the HsA interrupt (s15c). Elapsed time Rhp, that is, the paper feed suspension time (the energization continuation time of the heater 29a) after the image formation instruction is issued is updated (s32), and the paper feed suspension time Rhp is used for abnormality determination during the paper feed suspension period. It is confirmed whether or not the threshold value Eh has been reached (s33). If the threshold value Eh has been reached, the heater energization is stopped and “image temperature adjustment error”, “service man call”, and “image formation is possible if the paper temperature adjustment designation is canceled”. In addition to the “waiting” display, each part of the engine 50 is set in a standby state and waits for a new input (s42). Here, the heater energization time Rhp to be monitored for abnormality is the paper feed suspension time after the image forming instruction is given.

  If the paper supply holding time Rhp is less than the threshold value Eh, the temperature Ta detected by the temperature sensor 30a is read (s34), the temperature increase rate Vt for the HsA period immediately before the current time is calculated and written to the memory (temperature register) (s35). ). Then, the write count Rmc is incremented by 1 (S36), and it is confirmed whether the write count Rmc has reached 4 times (s37). The process returns to the main routine (FIG. 5) immediately before entering the process INTA.

  When the write count Rmc reaches four times, an average value MVt of the four temperature rise rate calculated values Vt1 to Vt4 on the memory is calculated (s38), and the calculated data Vt1 to Vt4 and the write count of the memory are set to 0. (S39). Then, a time Wt until the first set temperature Ts1 is reached from the detected temperature Ta read in step s34 is calculated by a prediction (estimation) calculation (s40), and the time Wt as a waiting time until the start of image formation is displayed in s15a. In addition to the “waiting” display that has been started (s41), the process exits the interrupt process INTA and returns to the main routine (FIG. 5) immediately before entering the interrupt process INTA. Other functions of the paper temperature adjustment of the third embodiment are the same as those of the paper temperature adjustment (FIG. 4) of the second embodiment. The hardware and other functions of the third embodiment are the same as those of the first embodiment (FIGS. 1 and 2).

Example 4
The engine ASIC 51 of the fourth embodiment includes "starting energization of the heater 29a" (s4), "stopping energization of the heater 29a" (s8b) and "in the paper temperature adjustment (FIGS. 5 and 6) of the third embodiment. Paper temperature adjustment is performed by changing the “HsA interrupt” INTA to (a), (b) and (c) of FIG.

  Referring to (a) of FIG. 7, in “starting energization of heater 29 a” (s 4), reference is made to whether or not the first energization is started (s 51), and if it is, time It is started (s 52). The information FRi for determining whether or not it is the first is rewritten to “1” indicating that it is not the first (s53), and the heater 29a is energized (s54). Then, the process proceeds to the next step s9 (FIG. 5). When the heater 29a is already energized (FRi = “1”) when proceeding to “Start energizing the heater 29a” (s4), check whether the measured value It is equal to or higher than the abnormality determination threshold value Ehi. (S55), if it is equal to or higher than Ehi, the heater energization is stopped, “Paper temperature adjustment error”, “Service man call” and “Image can be set if paper temperature adjustment designation is canceled” are displayed as “Waiting”. In addition, each part of the engine 50 is set in a standby state to wait for a new input (s56). If it is less than Ehi, the process proceeds to the next step s9 (FIG. 5).

  Referring to (b) of FIG. 7, in “stop heater 29a energization” (s8b), the heater energization is first stopped (s61), the timing It is stopped and the timing value It is cleared (s62, s63). ), The heater energization information (FRi = “1”) is reset to information (FRi = “0”) indicating that the heater energization is stopped (s64), and the process proceeds to the next step s9 (FIG. 5).

  Referring to (c) of FIG. 7, in the “HsA interrupt” (s8b), when the timer HsA is restarted (s31), it is confirmed whether or not the measured value It is equal to or higher than the threshold value Ehi for abnormality determination ( s33v), if it is equal to or higher than Ehi, the heater energization is stopped, and “paper temperature adjustment error”, “service man call” and “image creation is possible if paper temperature adjustment designation is canceled” are added to the “waiting” display Therefore, each part of the engine 50 is set in a standby state and waits for a new input (s42). If it is less than Ehi, the processing from step s34 is performed as in the third embodiment (FIG. 6). In the fourth embodiment, the energization time value It is the heater energization time from when the energization of the heater 29a is first started (s4) regardless of whether an image formation instruction is received. Other functions of the paper temperature adjustment of the fourth embodiment are the same as those of the paper temperature adjustment of the third embodiment (FIGS. 5 and 6). The hardware and other functions of the fourth embodiment are the same as those of the first embodiment (FIGS. 1 and 2).

  In any of the first to third embodiments (FIGS. 3 to 5), “start energization of heater 29a” s4 is replaced with the content shown in FIG. 7A and “stop energization of heater 29a”. There is also an aspect in which s8 and s8b are replaced with the contents shown in FIG. 7B, and an abnormality in which the heater energization is too long while waiting for an image formation instruction is monitored.

21: transfer belt 22: photosensitive drum 23: charging roller 24: optical writing unit 25: developing unit 26: transfer roller 28a, 28b: paper feed tray 28af, 28bf: paper feed roller (feeding means)
29a, 29b: heater (heating means)
30a, 30b: Temperature sensor (temperature detection means)
33: Conveying belt 34: Fixing unit (fixing device)
35: Double-sided drive unit 41: Controller ASIC (image data processing means)
51: Engine ASIC (recording paper feed control means)

JP 2002-55564 A Japanese Patent Laid-Open No. 7-13462 JP-A-7-53075 JP-A-7-121090

Claims (12)

Paper tray;
A feeding means for feeding and feeding the recording paper on the paper feed tray;
Heating means provided on a bottom plate of the paper feed tray ;
Temperature detecting means for detecting the temperature of the upper space of the recording paper on the paper feed tray when the operation power is turned on;
When the temperature is lower than the first set temperature, heating is started using the heating means. When the second set temperature equal to or higher than the first set temperature is reached, the heating is stopped or the temperature is lowered, and the temperature is set to the first set temperature. A recording paper feed control means for holding the feeding of the recording paper by the feeding means below the temperature and feeding the recording paper by the feeding means at a first set temperature or higher;
A paper feeding device comprising:   The recording paper feeding control means holds the feeding of the recording paper by the feeding means when the temperature is lower than a first set temperature when the paper temperature adjustment is specified, and the feeding is performed at a temperature equal to or higher than the first set temperature. 2. The paper feeding device according to claim 1, wherein the recording paper is fed by means, and when the paper temperature adjustment is not specified, the recording paper is fed by the feeding means regardless of the temperature.   The paper feeding device according to claim 1, wherein the recording paper feeding control unit issues a waiting notification while the feeding of the recording paper is suspended.   The recording paper feed control means derives and reports a waiting time until the temperature reaches the first set temperature or more while the feeding of the recording paper is suspended; The paper feeder described.   The sheet feeding device according to any one of claims 1 to 4, wherein the second set temperature is the same as the first set temperature.   The sheet feeding device according to any one of claims 1 to 4, wherein the second set temperature is higher than the first set temperature.   The recording paper feed control means refers to the temperature detected by the temperature detection means at a set time period while waiting for a paper feed instruction, and starts heating using the heating means if the temperature is lower than the first set temperature. The sheet feeding device according to any one of claims 1 to 6, wherein when the temperature reaches a second set temperature that is equal to or higher than the 1 set temperature, the heating is stopped or the temperature is decreased.   The sheet feeding device according to any one of claims 1 to 7, wherein the recording sheet feeding control unit reports an abnormality when a duration time of the waiting notification becomes a set value or more;   The recording paper feed control means starts timing when heating is started using the heating means while waiting for a paper feed instruction, and when the heating is continued, the time measured value reaches a set value or more. Then, the abnormality is notified; The sheet feeding device according to any one of claims 1 to 7. A paper feeding device according to any one of claims 1 to 9;
An electrostatic latent image is formed on the photosensitive member, the electrostatic latent image is developed and visualized, and the developed image is transferred directly or indirectly to the recording paper fed by the paper feeding device via the intermediate transfer member. An electrophotographic imaging device; and
A fixing device for fixing the visible image on the recording paper by heating and pressurizing the recording paper on which the visible image is transferred by the imaging device;
An image forming apparatus comprising:   Furthermore, an image reading device that reads an image on a document and generates image data; and image data that is converted into recording image data that conforms to the image forming characteristics of the image forming device and is given to the image forming device The image forming apparatus according to claim 10, further comprising a processing unit.   12. The image forming apparatus according to claim 11, wherein the image data processing means further converts document information given from the outside into image data for recording and gives the image forming apparatus.

Images