JP2015001677A - Image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the trouble in sheet conveyance due to the inappropriate water content of sheets in paper cassettes.SOLUTION: An image forming apparatus detects and stores the remaining amount of sheets in each paper cassette (S2), compares, upon detection of the paper cassettes having been withdrawn and re-attached to the image forming apparatus (S3, S4), the remaining amount of sheets X2 at the time of the re-attachment with the remaining amount of sheets X1 before the withdrawn (S6), stores the date if the remaining amount of the sheets is increased (S7), and sets the paper cassette with the oldest date as a paper feed object (S9).

Description

  The present invention relates to an image forming apparatus such as a printer, a copier, a facsimile machine, a multi-function machine, and the like. More particularly, the present invention relates to feeding of sheets from each paper feed cassette.

  2. Description of the Related Art Conventionally, some image forming apparatuses are provided with a sheet cassette heater (dehumidifier) in the apparatus in order to remove the humidity of sheets (paper) in the sheet cassette. In high humidity environments, paper is easy to absorb moisture. Paper that absorbs moisture and contains moisture may cause curling because of its tendency to curl, and image defects such as transfer defects may occur due to the influence of moisture. Therefore, the humidity is removed by a paper feed cassette heater (dehumidifier) so that the moisture content of the paper in the apparatus does not increase.

  A sheet dehumidifying device in a conventional image forming apparatus is described in Patent Document 1. This apparatus estimates the amount of moisture absorption of the entire paper based on the detected humidity, the amount of paper (sheet), and the paper size, and determines the wattage and on-time of the heater.

JP 2000-255807 A

  Conventionally, when paper is just put in a paper feed cassette, it may be fed before the effect of dehumidification by the paper feed cassette heater is produced. Depending on the amount of water contained in the paper, it takes 1 to 2 days from the time the paper is placed in the cassette to the familiarity. Also, until the paper adapts to the environment inside the cassette, moisture will be removed from the edge of the paper, leaving it in the center, and there is a possibility that transfer will be lost or only one side will curl, causing jam etc. Come out. On the other hand, paper that has been left in the cassette for a long time causes moisture to come in and out of the paper due to the opening and closing of the cassette and the cassette heater, so there is also the possibility of paper wavy and the resulting wrinkles and jams. Come.

  In Patent Document 1, the output of the heater is controlled in consideration of the amount of paper, it is possible to remove moisture from the paper located in the middle of the paper feed cassette, and quick dehumidification of the loaded paper. Can be performed. However, this system detects the humidity and amount of paper in the entire paper storage unit containing a large number of paper feed cassettes, and controls the heating by the heater, so the paper (sheets) of each paper feed cassette is considered. It has not been. Therefore, even in this case, the above-described problem occurs due to a time difference after the sheet is supplied to the sheet feeding cassette.

  Therefore, according to the present invention, the date (including date and time) when sheets are supplied to each sheet feeding cassette is stored, and the old one is preferentially fed so that the moisture in the sheets in the sheet feeding cassette is inappropriate. The purpose is to reduce problems such as sheet conveyance.

  The present invention is provided so as to be capable of being pulled out from the apparatus main body, and is in a state in which a plurality of sheet feeding cassettes for stacking sheets and the respective sheet feeding cassettes are pulled out from the apparatus main body and mounted in the apparatus main body. A sheet cassette presence / absence detecting unit for detecting whether or not, a sheet remaining amount detecting unit for detecting a remaining amount of sheets stacked on each sheet cassette, and a sheet for each sheet cassette by the sheet remaining amount detecting unit. And when the presence of the sheet cassette is detected after the sheet cassette presence / absence detecting unit detects the absence of the sheet cassette, the sheet after the presence of the sheet cassette is detected. When the remaining amount of paper is greater than the remaining amount of sheets before the absence of the paper feed cassette is detected, the storage means for storing the date and the paper feed cassette in which the same type of sheets are stacked Of the date stored in the storage means comprises a cassette control means for setting the paper feed cassette of earliest date as the paper target, and in the image forming apparatus characterized by.

  Note that the date is not limited to a simple year, month, and day, but may include time (hour, minute, etc.), and the point means any delimiter when the time has passed.

  According to the first or fourth aspect of the present invention, the date when a sheet is newly supplied is stored for each of the plurality of paper feed cassettes, and the oldest one (or the dehumidifier is activated) from among the paper feed cassettes. The date before the predetermined time) is set as the paper feed target. Therefore, for example, dehumidified by a dehumidifying device and a stable sheet can be fed, and problems such as curl and corrugated sheet jams, and transfer defects due to moisture remaining only partially can be reduced. it can.

  According to the second aspect of the present invention, the date when the sheet is supplied to the sheet feeding cassette is stored, and the date is displayed on the operation unit of the apparatus main body. Thereby, the user can recognize when the sheets in the sheet feeding cassette are replenished.

1 is a cross-sectional view illustrating an entire image forming apparatus to which the present invention is applied. (A) The perspective view which shows a paper feed cassette, (B) is a top view which shows the action | operation of the cassette presence / absence detection means. The control block diagram. FIGS. 9A to 9D are cross-sectional views illustrating sheet remaining amount detection of the sheet feeding cassette, and FIGS. The flowchart by embodiment of this invention. The figure of the operation part screen by this embodiment. FIGS. 9A to 9D are cross-sectional views illustrating sheet remaining amount detection of a sheet feeding cassette according to another embodiment, and FIGS. The flowchart by other embodiment. The control block diagram.

  Embodiments of the present invention will be described below. The present invention can be applied to image forming apparatuses such as copying apparatuses, printers, and facsimiles, and the dimensions, materials, shapes, relative arrangements, and the like of components described in the following embodiments are particularly specific. As long as there is no description, it is not limited only to them.

  First, the configuration and operation of a color image forming apparatus to which the present invention can be applied will be described with reference to FIG. Although the present embodiment is an electrophotographic color image forming apparatus, the type of the image forming apparatus can be similarly applied to an electrostatic recording type or a monochromatic image forming apparatus.

  The image forming apparatus K includes an apparatus (printer) main body 1, and an engine portion Y for forming primary images of four colors of yellow, magenta, cyan, and black in the printer main body 1. M, C, and Bk are arranged. Print data transmitted from an external device such as a personal computer is received by a controller that controls the printer main body 1 and is output as write image data from the laser scanner 2 to the engine unit of each color.

  The laser scanner 2 emits a laser beam onto the photosensitive drum of the engine unit for each color, and draws an optical image according to the written image data. The images on the intermediate transfer belt 3 are matched by adjusting the writing start timing of the laser scanner 2 for each color. The primary image forming unit for each color has a photosensitive drum of the engine unit. Further, the image forming apparatus includes a developing device for developing the electrostatic latent image created by the laser scanner 2 drawing an optical image on the surface of the photosensitive drum into a toner image to be transferred to the intermediate transfer belt 3. Further, a primary transfer roller 4 for transferring the toner image developed on the surface of the photosensitive drum to the intermediate transfer belt 3, and a cleaner 5 for removing the toner remaining on the photosensitive drum after transferring the toner image. Have. The toner image primarily transferred to the intermediate transfer belt 3 is retransferred onto the sheet by the secondary transfer roller 6. The toner remaining without being transferred by the secondary transfer roller 6 is collected by the cleaner 5.

  The image forming apparatus K includes a cassette storage unit 31 installed in the printer main body 1 and an additional cassette storage unit 32 disposed in the lower part of the printer main body 1. Two cassettes, that is, a total of four (plural) sheet cassettes 16, 17, 18, and 19 are removably mounted in both cassette storage units 31 and 32, respectively. An additional cassette storage section 32 is also installed integrally with the printer main body 1, and all the paper feed cassettes 16 to 19 are inserted into and removed from the printer (device) main body 1 and attached to the device main body. Is done. Each storage cassette is provided with a sheet stacking plate 8, and sheets S are stacked on the sheet stacking plate 8.

  A paper feed roller 7 serving as a paper feed unit is disposed at a position corresponding to the upper side of each of the paper feed cassettes 16 to 19, and a retard roller 33 serving as a separation unit is disposed so as to contact the paper feed roller 7. ing. In each of the cassettes 16 to 19, the sheet feeding stacking plate 8 pushes up the sheet S to the sheet feeding roller 7, picks up the uppermost sheet by the sheet feeding roller 7, and sends it out downstream. The sheet S fed from the paper feed roller 7 is conveyed downstream through a vertical conveyance path 9. A registration roller 10 is provided in the middle of the vertical conveyance path 9 to correct the skew of the sheet, and the registration roller 10 matches the timing of image writing and sheet conveyance in the image forming unit. The toner image on the intermediate transfer belt 3 is sent to the secondary transfer roller 6 of the intermediate transfer belt 3 at a timing for aligning the position of the toner image with the leading edge of the sheet S, and the toner image is transferred onto one surface of the sheet S to form an image. . A fixing device 11 for fixing the toner image on the sheet S as a permanent image is provided on the downstream side of the image forming unit.

  The sheet S on which the image is fixed is discharged out of the apparatus by the paper discharge roller 12 and stacked on the paper discharge stacking unit 13. In the color image forming apparatus K, a duplex mode (image formation on both sides of a sheet) can be executed. When forming a double-sided image of the sheet S, after passing through the fixing device 11, the sheet S is guided by switchback reverse conveyance by the paper discharge roller 12. Then, the sheet S reversely conveyed by the paper discharge roller 12 is guided to the double-sided conveyance path 14 and conveyed downward in the double-sided conveyance path 14 by the double-sided conveyance roller 15. The downstream end of the double-sided conveyance path 14 merges with the vertical conveyance path 9, and the sheet S that has passed through the double-sided conveyance path 14 is introduced into the vertical conveyance path 9. Then, after passing through the vertical conveyance path 9 and performing image formation on the back surface, the sheet S with the image fixed on both surfaces is sent to the paper discharge roller 12 and discharged from the apparatus main body.

  In the cassette storage unit 31 and the additional cassette storage unit 32 in the printer main body 1, a paper feed cassette heater (dehumidification) is provided below the paper feed cassettes 17 and 19 to remove the humidity of the paper in the cassette. Apparatus) 20 and 21 are provided. As a cassette heater, a well-known structure as described in JP2010-122334A can be used. The paper feed cassette heaters 20 and 21 are configured to raise the temperature and lower the humidity in the cassette housings 31 and 32 where the paper feed cassettes are located. The user can set the temperature setting of the paper feed cassette heaters 20 and 21 to be constant day and night.

  As shown in FIG. 2, a cassette presence / absence detection switch (paper cassette presence / absence detection means) 22 for detecting attachment / detachment of the paper feed cassette is provided at the back of each of the paper feed cassettes 16 to 19 in the cassette storage units 31 and 32. It is provided to detect attachment / detachment for each paper feed cassette. The cassette presence / absence detection switch 22 detects the presence of a cassette by contacting the cassette presence / absence detection switch 22 and turning off the cassette when the cassette is in the mounting position with respect to the cassette housing portions 31 and 32 as the printer body. In other cases, it is detected that there is no cassette in the mounting position by not turning off the cassette presence / absence detection switch 22. The cassette presence / absence information by the cassette presence / absence detection switch 22 is stored in the CPU 24 or the memory (storage means) 25 in the control unit (cassette control means) 23 of the main body shown in FIG. In addition, the memory (storage means) 25 stores information such as the paper type of the paper feed cassette, the paper size in the paper feed cassette, the paper type, and the basis weight for each paper feed cassette. The paper size information can also be detected by a side guide or a rear end guide that sets the position of the paper in the paper feed cassette. The type and basis weight of the paper are set and stored by input from the operation unit 26. The stacking plate 8 of each sheet cassette is raised by the stepping motor in accordance with the remaining amount of the sheet reduced by the pickup by the sheet feed roller 7. The rotation position of the stepping motor corresponding to the position of the stacking plate 8 is controlled by the control unit 23. Further, the sheet feeding cassette heaters (dehumidifying devices) 20 and 21 are controlled by a signal from the control unit 23.

  With reference to FIG. 4, the operation of the remaining sheet detecting means 27 when the sheet is supplied to the sheet feeding cassette will be described. A sheet presence / absence detecting unit 28 that detects whether or not there is a sheet on the stacking plate 8 of each of the sheet feeding cassettes 16 to 19 and a sheet remaining amount detecting unit 27 that detects the remaining amount of sheets in the sheet feeding cassette are provided. As shown in FIG. 4D, in the sheet presence / absence detection means 28, a flag 28a is rotatably supported so that a leading end enters a through hole formed in the stacking plate 8, and a photo sensor or a contact is supported by the flag 28a. A switch 28b consisting of a switch is switched ON and OFF. If there is even one sheet on the stacking plate 8, the flag 28a does not contact the sheet and enter the through hole, and the switch 28b is in the OFF position away from the flag 28a and displays the sheet presence information. To emit. If there is no sheet on the stacking plate 8, the leading edge of the flag 28a enters the through hole, and the switch 28b is in the ON position with the optical path closed by the flag 28a (or in contact with the flag) and emits no sheet information.

  The sheet remaining amount detecting means 27 has two switches 27A and 27B that are switched ON and OFF depending on the position of the drive unit that operates the stacking plate 8. The drive unit includes a sector gear 40 that integrally fixes a pinion gear 37 provided on an output shaft 36 of a stepping motor and a lifter arm 29 that supports the stacking plate 8. The pinion gear 37 and the sector gear 40 are engaged with each other, and the lifter arm 29 is rotated via the pinion gear 37 and the sector gear 40 by the rotation of the stepping motor, so that the elevation position of the stacking plate 8 is adjusted. The two switches 27A and 27B are composed of photosensors (or contact switches), and the flag is switched ON and OFF across the optical path (or in contact with the flag) according to the rotational position of the sector gear 40.

  When the sheet is full or close to the sheet cassette, as shown in FIG. 4A, the sheet remaining amount detecting means 27 has both switches 27A and 27B in the OFF state. When the number of sheets in the sheet feeding cassette is reduced by the sheet feeding roller and the remaining amount of the sheet becomes about half, as shown in FIG. 4B, one switch 27B is in the OFF state but the other switch 27A is turned on. Switched. Further, when the number of sheets in the sheet feeding cassette decreases and the remaining amount of sheets becomes small, as shown in FIG. 4C, one switch 27B is also turned ON, and both switches 27A and 27B are both in the ON position. Become. When there is no sheet on the stacking plate 8 of the sheet cassette, the switch 28b of the sheet presence / absence detecting means 28 is turned on as shown in FIG. As a result, the three switches 28b, 27A, and 27B detect a state in which there is no sheet in the sheet feeding cassette, a state in which the remaining amount of the sheet is small, a state that is approximately half, and a state that is nearly full.

  In the above embodiment, the stacking plate 8 of each sheet feeding cassette is driven by the stepping motor to lift the stacking plate so that the sheet surface to be fed is always constant with respect to the sheet feeding roller. The loading plate may be lifted by a spring or the like.

  That is, when there is no paper (sheet) in the paper feed cassette, the paper presence / absence detection switch 28b is turned on. When the amount of paper is small, both the remaining paper amount detection switch 27A and the remaining paper amount detection switch 27B are ON and the paper presence / absence detection switch is OFF. When the remaining amount of paper is about 50%, the remaining amount detection switch 27A is ON, the remaining amount detection switch 27B is OFF, and the presence / absence detection switch is OFF. When the paper is almost full, both the remaining paper amount detection switch 27A and the remaining paper amount detection switch 27B are OFF and the sheet presence / absence detection means 28 is OFF. It is also possible to detect a finer remaining amount by increasing the number of switches of the remaining sheet detecting means 27.

  FIG. 5 is a flowchart showing a process for setting a paper feed target cassette according to the present invention. The date (date and time) T1 when the sheet has reached the predetermined remaining amount X0 (substantially full) in the paper feed cassette (for example, 17) is stored in the memory (storage means) 25 (S1). The above date can be any number of years, months, days, but what time, sometimes hours and minutes can be used. In short, the date is not just a day, it can distinguish the passage of old and new time. . When a sheet is fed from the sheet feeding cassette 17 and the remaining amount of sheets stacked on the stacking plate 8 is reduced, the remaining sheet amount detecting unit 27 detects the remaining sheet amount X1, and the memory (storage unit). ) 25. That is, for each print job, the remaining sheet amount X1 of the used paper cassette 17 is detected and stored in the memory 25 (S2). It is detected by the cassette presence / absence detection means 22 that the paper feed cassette 17 has been pulled out of the apparatus (S3), and the cassette presence / absence detection means 22 again detects that the paper feed cassette has been returned to a predetermined position of the main body (S4). ). The remaining sheet quantity X2 when the cassette presence / absence detecting means 22 detects the presence of a cassette is detected by the remaining sheet quantity detecting means 27 (S5). The sheet remaining amount X2 at this time is compared with the previous sheet remaining amount X1 (S6). If the sheet remaining amount X2 is larger than the previous sheet remaining amount X1 (X1 ≧ X2; NO), a sheet is loaded in the cassette. It is determined that the supply has been made, and the date (date and time) T2 is stored in the memory 25 (S7). For example, the predetermined remaining amount X2 (50% remaining amount) increases from the predetermined remaining amount X1 (substantially full), or no paper or the predetermined remaining amount X3 (small amount) increases to the predetermined remaining amount X2 (50% remaining amount). This corresponds to an increase in the remaining sheet capacity. On the contrary, when the remaining amount is reduced or there is no change, it is determined that the sheet is not supplied to the cassette even by pulling out the paper feed cassette, and the memory 25 is left with the date (date and time) T1 at the previous replenishment. Is not updated (S6; YES). Accordingly, each paper cassette is not necessarily replenished so as to be fully loaded, and even when a small number of sheets are increased, it is determined that the sheet is replenished, and the date is stored.

  It is determined whether the paper size, basis weight, and paper type of each of the paper feed cassettes 16, 17, 18, and 19 stored in the memory 25 match the sheets of the predetermined paper feed cassette 17 (S8). Similarly to the predetermined sheet feeding cassette 17, the sheet replenishment date (date and time) is stored in the memory 25 for all the cassettes 16, 17, 18, and 19. If there is a cassette having the same sheet size or the like in step S8, the date (date and time) stored in the memory 25 is compared. The oldest date (date and time) is selected and set so as to give priority to the cassette to be fed (S10). The remaining amount of sheets in the sheet feeding cassette after the main power of the printer main body is turned off and before the power is turned off is stored in the memory 25, and the remaining amount of sheets when the main power is turned on. In comparison, the date (date and time) of the remaining amount of sheets is stored in the memory 25. Based on the stored date (date and time), when there is a paper feed cassette of the same paper type / same paper size, the oldest one is preferentially used. Steps S6, S7, S8, S9, and S10 correspond to the control for setting the paper feed target by the cassette control means according to the present invention.

  In the above embodiment, the sheet size, basis weight (thickness), and paper type stored in each paper feed cassette are stored and the same type is selected, but only the sheet size is stored. You may select from among them. That is, the sheet cassettes loaded with the same type of sheets are loaded with sheets to be selected for image formation, such as sheets having the same sheet size, sheets having the same basis weight such as sheet size and sheet thickness, and the like. Means a paper cassette.

  Even when the sheet cassette heaters (dehumidifiers) 20 and 21 are in the ON state, the dehumidifying effect cannot be exhibited immediately after the sheets are put into the sheet cassette. For this reason, control is performed so as to preferentially use an old sheet (date and time) on which the sheet was replenished more than a predetermined time (for example, 24 hours) before the sheet feeding cassette heaters 20 and 21 are operating. That is, control is performed so that a paper feed cassette in which the dehumidifying device has been operating for a predetermined time or longer has been fed.

  FIG. 6 is a diagram showing a display of the operation unit 26. The date (date and time) when the paper cassette is almost full, which is stored in the memory 25 of the control unit, is automatically displayed on the operation unit and the paper feed stage portion of the print screen. When starting a job, the user can be notified or selected of the date and time (date) when the paper was replenished. In FIG. 6, A4 plain paper is selected, and a second-stage switch corresponding to an old (2012.6.01) paper feed cassette is turned on. As a result, the second-stage sheet cassette is distinguished from the other-stage sheet cassette switch part (corresponding part) that is not lit (dark), and the user recognizes that the sheet is to be fed. Then, the paper is fed by an OK operation. The user can select the mode that prioritizes the date and time (date) or whether to prioritize the speed of the first image.

  Next, another embodiment of the present invention will be described with reference to FIGS. Note that the same portions as those of the previous embodiment are denoted by the same reference numerals and description thereof is omitted. Also in the present embodiment, the cassette presence / absence detecting means 22 for detecting attachment / detachment of the paper feed cassette is provided to detect opening / closing of the paper feed cassette. The method of the cassette detection means is the same as described in the previous embodiment. Information on attachment / detachment of the paper feed cassette is stored in the control unit 23 of the main body by the CPU 24 or the memory (storage means) 25. In addition, the memory (storage means) 25 stores information such as the paper type, paper size, and basis weight in the paper feed cassette for each paper feed cassette.

  The sheet remaining amount detection when sheets are supplied to the sheet cassette will be described with reference to FIG. When the cassette presence / absence detection means 22 detects that the paper feed cassette is in the loading position, and the sheet presence / absence detection means 28 of the paper feed cassette detects that there is a sheet on the stacking plate 8, the lifter driving stepping motor 30 is turned on. To drive. The rotation of the stepping motor 30 rotates the lifter arm 29 integrally through the pinion gear 37 and the sector gear 40, lifts the sheet by the sheet feeding stacking plate 8, and the sheet surface to be fed is always constant with respect to the sheet feeding roller. To be.

  The remaining amount of sheets in the sheet feeding cassette is stored in the memory (storage means) 25 as the remaining amount information according to the number of driving steps in which the lifter driving stepping motor 30 rotates. The paper feed stacking plate 8 is lifted so that the paper surface to be fed is always constant with respect to the paper feed roller.

  Accordingly, by counting the driving steps of the lifter driving stepping motor 30, the sheet is moved by the lifter arm 29 from the lowest position of the sheet stacking plate to the sheet feeding roller based on the amount of movement until the sheet stops. Detect the remaining amount.

  FIG. 7A shows a state in which sheets S are fully loaded (or a state close to that) in a paper feed set (for example, 17). FIG. 7B shows a case where the sheet is half, FIG. 7C shows a small amount, and FIG. When there is no sheet on the stacking plate 8, the sheet stacking plate 8 is lifted from the lowest position to the maximum sheet feeding position, and the number of steps of the lifter driving stepping motor 30 at this time is maximum P0. . This value is set as P0, and the value of the number of steps driven by the lifter driving stepping motor 30 is stored in the memory (storage means) 25 as information on the remaining sheet amount.

  FIG. 8 is a flowchart showing a process for setting a cassette to be fed. FIG. 9 is a block diagram showing control of the paper feed cassette. The processing in FIG. 8 is executed, for example, after executing a print job (every time after job processing). The date and time (date) when the paper cassette (for example, 17) reaches a predetermined remaining amount X0 (substantially full) by detecting that the number of sheets in the cassette has increased. ) T3 is stored in the memory 25 (S11). Then, after executing the print job, the remaining amount of paper X1 in the paper cassette is always stored in the memory 25 (S12). It is detected by the cassette presence / absence detection means 22 that the paper feed cassette 17 has been pulled out from the apparatus main body (S13), and the cassette presence / absence detection means 22 detects that the cassette has been loaded again (S14). At this time, an amount obtained by subtracting a step count from the lowermost position of the paper feed stacking plate 8 of the lifter driving stepping motor 30 from a predetermined number of steps is stored in the memory as the remaining paper amount X. The sheet remaining amount X when the sheet feeding cassette 17 is returned to the predetermined position of the main body is compared with the previous sheet remaining amount X1 stored in the previous print job. If the sheet remaining amount X is larger than the sheet remaining amount X1 and is less than or equal to the substantially full sheet remaining amount X0, it is determined that the sheet has been replenished and the date (date / time) T4 is stored in memory. The data is stored in (storage means) 25 (S17). In other words, the memory is updated when the remaining amount of sheets increases. On the contrary, when the remaining amount is reduced or there is no change, the full date is not updated.

  The date (date and time) of the full load history of each paper feed cassette stored in the memory (storage means) 25 of the control unit 23 is automatically displayed on the operation unit 26 or the paper feed stage portion of the print screen. The oldest history of each paper cassette is notified to the user by changing the color, size, etc. (S18).

  In the embodiment described above, the oldest of the paper cassettes is set as the paper cassette and displayed on the operation unit 26 of the apparatus main body so that it can be distinguished from other paper cassettes. The sheet is fed from the sheet feeding cassette by selecting it. Not limited to this, the oldest paper cassette is set from among the paper cassettes loaded with sheets of the same size (or the same paper type and basis weight in addition to the same size). Alternatively, paper may be fed.

  In addition, a paper feed cassette with a date (history information) older than a predetermined time (for example, 24 hours) during which a dehumidifier such as a cassette heater is operating is set as a paper feed target, and the paper feed target cassette is displayed. The user may select and feed paper from among them.

  In the above description of the embodiment, the configuration in which the paper feed cassette heater (dehumidifying device) is provided has been described, but the present invention should not be limited to this. The feature of this embodiment is that when a sheet is supplied to the sheet cassette, the memory stores the date (date and time), and it is possible to determine whether the sheet is familiar with the environment in the sheet cassette. .

  For example, by displaying the date when a sheet is replenished on the operation unit of the apparatus main body, the user can determine whether or not the sheet in the sheet cassette is familiar with the environment in the sheet cassette. Further, by comparing the dates stored in the memory by the CPU, it is possible to set a sheet that is familiar with the environment in the sheet feeding cassette from among a plurality of sheet feeding cassettes as a sheet feeding target.

S sheet K image forming apparatus 1 apparatus (printer) main body 8 (paper feeding) stacking plates 16, 17, 18, 19 paper feeding cassette 20, 21 dehumidifying device (paper feeding cassette heater)
22 Feed cassette presence / absence detection means (switch)
23 Control unit (control means)
25 Storage means (memory)
26 Display means (operation unit)
27 Sheet (paper) remaining amount detection means 28 Sheet (paper) presence / absence detection means 29 Lifter arm 30 Stepping motors 31, 32 Cassette housing portion

Claims (15)

A plurality of paper feed cassettes provided so as to be capable of being pulled out from the apparatus main body,
Paper feed cassette presence / absence detecting means for detecting whether each of the paper feed cassettes is pulled out from the apparatus main body and attached to the apparatus main body;
Sheet remaining amount detecting means for detecting the remaining amount of sheets stacked in each sheet cassette;
This is a case where the remaining amount of sheets for each sheet feeding cassette by the sheet remaining amount detecting unit and the presence of the sheet feeding cassette are detected after the sheet feeding cassette presence / absence detecting unit detects the absence of the sheet feeding cassette. Storage means for storing the date when the remaining amount of the sheet after the presence of the sheet cassette is detected is greater than the remaining amount of the sheet before the absence of the sheet cassette is detected. When,
Cassette control means for setting, as a paper feed target, the paper feed cassette having the oldest date among the dates stored in the storage means among the paper feed cassettes loaded with the same type of sheets;
An image forming apparatus. A plurality of paper feed cassettes provided so as to be capable of being pulled out from the apparatus main body,
Paper feed cassette presence / absence detecting means for detecting whether each of the paper feed cassettes is pulled out from the apparatus main body and attached to the apparatus main body;
Sheet remaining amount detecting means for detecting the remaining amount of sheets stacked in each sheet cassette;
The remaining amount of sheets for each sheet feeding cassette by the sheet remaining amount detecting means, and the presence of the sheet feeding cassette after the sheet feeding cassette presence / absence detecting means detects the absence of the sheet feeding cassette, and Storage means for storing the date when the remaining amount of sheets after the presence of the sheet cassette is detected is greater than the remaining amount of sheets before the absence of the sheet cassette is detected;
Display means for displaying a date for each of the paper feed cassettes stored in the storage means on an operation unit of the apparatus main body,
An image forming apparatus. A dehumidifying device is disposed in a cassette housing portion that houses the paper feeding cassette.
The image forming apparatus according to claim 1. A plurality of paper feed cassettes provided so as to be capable of being pulled out from the apparatus main body,
A dehumidifying device disposed in a cassette housing for housing the paper feed cassette;
Paper feed cassette presence / absence detecting means for detecting whether each of the paper feed cassettes is pulled out from the apparatus main body and attached to the apparatus main body;
Sheet remaining amount detecting means for detecting the remaining amount of sheets stacked in the sheet cassette;
The remaining amount of sheets for each sheet feeding cassette by the sheet remaining amount detecting means, and the presence of the sheet feeding cassette after the sheet feeding cassette presence / absence detecting means detects the absence of the sheet feeding cassette, and Storage means for storing the date when the remaining amount of sheets after the presence of the sheet cassette is detected is greater than the remaining amount of sheets before the absence of the sheet cassette is detected;
Cassette control means for setting, as a paper feed target, the paper feed cassette in which the dehumidifying device has been operating for a predetermined time or more in the paper feed cassette loaded with the same type of sheets;
An image forming apparatus. The storage means detects the remaining amount of sheets detected by the remaining sheet amount detecting means after the presence of the sheet feeding cassette is detected, and the remaining sheet amount detecting means before detecting the absence of the sheet feeding cassette. To determine whether the remaining amount of sheets has increased by comparing the remaining amount of sheets detected by
The image forming apparatus according to claim 1. An operation unit for selecting and feeding the plurality of paper feed cassettes;
A portion corresponding to the paper feed cassette set as a paper feed target by the cassette control means in the operation unit is displayed so as to be distinguishable from a corresponding portion of another paper feed cassette;
The image forming apparatus according to claim 1, or 3 to 5. The cassette control means automatically selects and feeds sheets of the paper feed cassette set as a paper feed target;
The image forming apparatus according to claim 1, or 3 to 6. For each of the paper feed cassettes, the size of the sheet is stored in the storage means,
The cassette control means sets a sheet feed target in the sheet cassette loaded with sheets of the same size;
The image forming apparatus according to claim 1, or 3 to 7. For each of the paper feed cassettes, in addition to the sheet size, the paper type and basis weight are stored in the storage means,
The cassette control means sets a paper feed target in the paper feed cassette loaded with sheets of the same size, paper type and basis weight;
The image forming apparatus according to claim 8. A loading plate provided in the sheet feeding cassette and on which sheets are stacked;
A sheet presence / absence detecting means for detecting that a sheet is not stacked on the stacking plate;
Adding the sheet presence / absence detecting means to the remaining sheet quantity detecting means to detect the remaining sheet quantity of each of the paper feed cassettes;
The image forming apparatus according to claim 1. The cassette control means detects the presence of the paper feed cassette after the paper feed cassette presence / absence detection means detects the absence of the paper feed cassette, and detects the presence of the sheet after the presence of the paper feed cassette is detected. If the remaining amount is not greater than the remaining amount of sheets before the absence of the sheet cassette is detected, the date stored in the previous storage unit is stored in the storage unit as history information as it is;
The image forming apparatus according to claim 1, or 3 to 10. A display means for displaying the date stored in the storage means for each of the paper feed cassettes in an operation unit for selecting and operating each of the paper feed cassettes.
The image forming apparatus according to claim 1, or 3 to 9. Provided in the paper feed cassette, comprising a stacking plate on which sheets are stacked;
The sheet remaining amount detecting means has a plurality of switches that are switched on and off corresponding to the position of the stacking plate.
The image forming apparatus according to claim 1. Provided in the paper feed cassette, comprising a stacking plate on which sheets are stacked;
The loading plate of each of the paper feed cassettes is driven by a stepping motor,
The sheet remaining amount detecting means detects the sheet remaining amount by counting the number of driving steps of the stepping motor.
The image forming apparatus according to claim 1. The sheet remaining amount detecting means detects the sheet remaining amount after each job processing of the image forming apparatus.
The image forming apparatus according to claim 1.

Images