JP2012086966A - Image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve a problem that a correlative relationship between a drive amount of a motor and an actuation amount of a lifter fluctuates depending on the weight and thickness of a recording material in a constitution in which the motor which is a driving source in a loading section and the lifter which is a loading plate are connected by an elastic spring.SOLUTION: When a first measurement value is defined as x1, a second measurement value is defined as x2 and a difference in the number Pn between the first and second recording material are ΔP12 based on the actuation amount of the lifter and a state of elastic spring, the number of the recording material is detected by Pn=ΔPn_n-1x(Xn-X0+(M0xg÷k)+Hs)÷(Xn-Xn-1).

Description

  The present invention relates to a method for detecting a remaining amount of recording material in a stacking unit on which recording materials of an image forming apparatus such as a copying machine, a laser beam printer (LBP), and an ink jet printer are stacked.

  2. Description of the Related Art Conventionally, an image forming apparatus is configured to form an image on a recording material by loading the recording material on a stacking unit and feeding the loaded recording material. In such a stacking unit, by detecting the remaining amount of the recording material stacked on the stacking unit, the user is prompted to replenish the recording material when the remaining amount is low. For example, Patent Document 1 discloses a method for detecting the remaining amount by detecting the number of pulses of a motor when a loading plate on which a recording material is loaded is lifted up.

JP-A-10-161376

  In the stacking unit, there is a configuration in which a motor, which is a drive source for lifting the stacking plate, and a stacking plate, on which a recording material is stacked, are connected via a spring (spring) which is an elastic member. In the configuration in which the motor and the stacking plate are connected using such a spring, the correlation between the number of pulses of the motor and the operating amount of the stacking plate varies depending on the difference in the weight and thickness of the recording material. Therefore, if the remaining amount is detected based on the number of pulses of the motor as in Patent Document 1, there is a possibility that the remaining amount of the recording material loaded on the loading unit cannot be detected with high accuracy.

  The invention according to the present application has been made in view of the above situation, and the remaining amount of recording material can be accurately obtained even in a configuration in which a driving source and a loading plate are connected via an elastic member as a configuration of the loading portion. The purpose is to detect.

  In order to achieve the above object, a stacking unit for stacking recording materials, a driving unit for driving the stacking unit, an elastic member for transmitting the drive from the driving unit to the stacking unit, and a stacking unit loaded on the stacking unit Detection means for detecting the presence or absence of the recording material being loaded, and control means for calculating the number of recording materials loaded on the stacking means, wherein the control means loads the first number of recording materials. The first operation amount when the loading means in the state of being driven is driven to the position where the recording material is detected by the detection means, and the second number of recording materials smaller than the first number are stacked. A second operating amount when the loading means is driven to a position where the recording material is detected by the detection means and a second amount of the recording material loaded on the loading means using the extension amount of the elastic member. It is characterized by calculating the number of sheets .

  According to the configuration of the present invention, the remaining amount of the recording material can be accurately detected even in the configuration in which the driving source and the stacking plate are connected via the elastic member as the configuration of the stacking unit.

Schematic configuration diagram of an image forming apparatus The block diagram which shows the engine control part of the image forming apparatus 100 Schematic configuration diagram for explaining the lift-up operation of the feeding unit 20 Schematic configuration diagram illustrating lift-down operation of feeding unit 20 Simplified configuration diagram for explaining a method for detecting the remaining amount of recording material Simplified configuration diagram for explaining a method of obtaining the number Pn of recording materials based on the lift operation amount Flow chart showing a method for detecting the number of recording materials Correspondence table for obtaining the number Pn of recording materials based on the lift operation amount and the slope of the lift operation amount equation

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The following embodiments do not limit the invention according to the scope of claims, and all combinations of features described in the embodiments are not necessarily essential to the solution means of the invention.

(First embodiment)
FIG. 1 is a schematic configuration diagram of an image forming apparatus. Hereinafter, the image forming apparatus 100 will be described in detail.

[Image formation process section]
The image forming apparatus 100 includes process cartridges 3a, 3b, 3c, and 3d that are detachable from the image forming apparatus 100. The process cartridges 3a, 3b, 3c, and 3d are different in the color of toner stored in yellow (Y), magenta (M), cyan (C), and black (Bk), but have the same structure. The process cartridges 3a, 3b, 3c, 3d have developing units 4a, 4b, 4c, 4d and cleaner units 5a, 5b, 5c, 5d. Further, the process cartridges 3a, 3b, 3c, 3d are the developing units 4a, 4b, 4c, 4d, the developing rollers 6a, 6b, 6c, 6d, the developer application rollers 7a, 7b, 7c, 7d, and the toner container. Have Photosensitive drums 1a, 1b, 1c, and 1d as image carriers and charging rollers 2a, 2b, 2c, and 2d are provided on the cleaner units 5a, 5b, 5c, and 5d side. Further, the cleaner units 5a, 5b, 5c, 5d have cleaning blades 8a, 8b, 8c, 8d and a waste toner container.

  A scanner unit 9 is arranged vertically below the process cartridges 3a, 3b, 3c, 3d, and exposes the photosensitive drums 1a, 1b, 1c, 1d based on image signals. The photosensitive drums 1a, 1b, 1c, and 1d are charged to a predetermined negative potential by the charging rollers 2a, 2b, 2c, and 2d, and then electrostatic latent images are formed by the scanner unit 9, respectively. The formed electrostatic latent images are reversed and developed by the developing units 4a, 4b, 4c, and 4d, and negative toner is attached to form Y, M, C, and Bk toner images, respectively.

  In the intermediate transfer belt unit 10, an intermediate transfer belt 10e is stretched around a driving roller 10f and a tension roller 10g, and the tension roller 10g applies tension in the direction of arrow T. Further, primary transfer rollers 10a, 10b, 10c, and 10d are arranged inside the intermediate transfer belt 10e so as to face the photosensitive drums 1a, 1b, 1c, and 1d. The toner images formed on the photosensitive drums 1a, 1b, 1c, and 1d are sequentially transferred from the photosensitive drum 1a to the intermediate transfer belt by applying a positive transfer bias to the primary transfer rollers 10a, 10b, 10c, and 10d. 10e is primarily transferred onto 10e. Then, the four color toner images are conveyed to the secondary transfer unit 13 in a state where they overlap.

[Cleaning part]
After the toner image is transferred, the toner remaining on the surface of the photosensitive drums 1a, 1b, 1c, 1d is removed by the cleaning blades 8a, 8b, 8c, 8d. Further, the toner remaining on the intermediate transfer belt 10 e after the toner image is secondarily transferred to the paper as the recording material S is removed by the transfer belt cleaning unit 11. The removed toner passes through a waste toner conveyance path (not shown) and is collected in a waste toner collection container (not shown) disposed in the back surface portion of the transfer belt cleaning unit 11.

[Secondary transfer section and fixing paper discharge section]
In the feeding unit 20 that feeds the recording material, the feeding roller 21 and the separation roller 22 separate the recording material S in the paper feeding cassette 30 one by one from the stack. The separated recording material S is conveyed to the secondary transfer unit 13 via the registration roller pair 14. In the secondary transfer unit 13, the toner image on the intermediate transfer belt 10 e is secondarily transferred onto the recording material S by applying a positive bias to the secondary transfer roller 13 a. The recording material S to which the toner image has been transferred is conveyed to the fixing unit 15 and heated and pressed by the fixing roller 15a and the pressure roller 15b to fix the toner image. The recording material S on which the toner image has been fixed is conveyed to the paper discharge roller pair 16 and discharged onto the paper discharge tray 17.

  FIG. 2 is a block diagram illustrating an engine control unit of the image forming apparatus 100. A host computer 110 transmits image information and a print command to the controller unit. A controller unit 111 analyzes image information received from the host computer 110 and transmits the image information to the video interface unit 114. Reference numeral 112 denotes a display unit that displays information of the image forming apparatus 100. The controller unit 111 can communicate with the host computer 110 and the engine control unit 113. The controller unit 111 transmits a print reservation command, a print start command, and a video signal to the engine control unit 113 for each recording material via the video interface unit 114.

  The engine control unit 113 includes a video interface unit 114, a CPU (central processing unit) 115, and a ROM 116 and a RAM 117 as storage means for storing information. When the engine reservation unit 113 receives the print reservation command from the controller unit 111 via the video interface unit 114, the engine control unit 113 controls the CPU 115 to prepare for execution of printing in the order of the print reservation command, and receives the print start command. Wait for. When the print start command is received, the controller unit 111 outputs a / TOP signal serving as a reference timing for outputting a video signal, and starts a print operation according to the print reservation command. The CPU 115 controls the driving force of the driving unit 119 in response to a signal from the detection unit 118 when performing a printing operation. The detection unit 118 is a paper feed cassette presence / absence sensor 120, a paper surface detection sensor 121, and the like, and the drive unit 119 is a stepping motor 122 and the like.

[Feeding department]
The feeding unit 20 will be described with reference to FIG. FIG. 3 is a schematic configuration diagram illustrating the lift-up operation. 3A shows a state before the lift-up operation is started, FIG. 3B shows a state during the lift-up operation, and FIG. 3C shows a state where the lift-up operation is completed.

  The sheet feeding cassette 30 is provided with a stacking plate 31 on which the recording material S is stacked so as to be rotatable around a rotation fulcrum 31a. A pressing lever 34 that pushes the stacking plate 31 toward the feeding roller 21 is disposed below the stacking plate 31. The pressing lever 34 is connected to a pressing arm 35 and is connected to a lifter rack 37 as a supporting means via a pressing spring 36 which is a pressing means made of an elastic member. The pressing lever 34, the pressing arm 35, the pressing spring 36, and the lifter rack 37 constitute lifter means that pushes up the stacking plate 31.

  A detection lever 23 and a detection photo interrupter 32 are installed beside the feeding roller 21 in the sheet feeding cassette 30 in order to detect the recording material S pushed up. The cassette gear 38 functions as a pinion gear for the lifter rack 37. The feeding unit 20 is provided with a drive transmission gear (not shown), and is driven by a motor (not shown) to transmit the drive to the cassette gear 38. When the paper feed cassette 30 is mounted on the feeding unit 20 of the image forming apparatus 100, the cassette gear 38 provided in the paper feed cassette 30 and the drive transmission gear provided in the feeding unit 20 are engaged. At this time, the position of the stacking plate 31 is the lowest position, and the state of the feeding unit 20 is the initial state.

[Lift up operation]
Next, the lift-up operation of the feeding unit 20 will be described with reference to FIGS. FIG. 3A shows an initial state of the feeding unit 20. An operation signal is sent from the engine control unit 113 to the stepping motor 122, and the stepping motor 122 starts rotating. When the stepping motor 122 starts to rotate, the lifter rack 37 starts to move in the direction of arrow P as shown in FIG. 3B via a drive transmission gear and a cassette gear 38 (not shown). The pressing arm 35 is rotated in the direction of arrow a in the figure by the pressure spring 36 connected so as to be pulled by the lifter rack 37, and the stacking plate 31 is raised via the pressing lever 34. Then, as shown in FIG. 3C, the lifter rack 37 moves to a position where the flag portion 37a shields the photointerrupter 24 from light. At this time, the detection lever 23 is rotated by the recording material S, and the detection photo-interrupter 32 that is in the light-shielding state is in a transmission state.

[Lift down operation]
Next, the lift-down operation of the feeding unit 20 will be described with reference to FIGS. FIG. 4A shows a state where the feeding unit 20 is lifted up. An operation signal is sent from the engine control unit 113 to the stepping motor 122, and the stepping motor 122 starts to rotate in the direction opposite to that during lift-up. When the stepping motor 122 starts to rotate, the lifter rack 37 starts to move in the direction of the arrow R as shown in FIG. 4B via a drive transmission gear (not shown) and the cassette gear 38. The pressing arm 35 is rotated in the direction of arrow b in the figure by the pressing spring 36 connected to the lifter rack 37, and the stacking plate 31 is lowered via the pressing lever 34. When the stepping motor 122 rotates by the number of steps T2 of the stepping motor 122 held during the lift-up operation, the state becomes as shown in FIG. 4C, and the stepping motor 122 is stopped and the lowering of the stacking plate 31 is stopped. When the loading plate 31 is lowered, the detection lever 23 pushed up by the recording material S loaded on the loading plate 31 is also lowered. Then, the detection photo interrupter 32 that has been in the transmissive state is shielded by the detection lever 23 again.

[Simplified drawing of feeding section]
Next, an algorithm for detecting the remaining amount of recording material will be described with reference to FIG. Here, for convenience of explanation, as shown in FIGS. 3 and 4, the recording material is not configured to be lifted up and down obliquely with respect to the recording material, but as a simplified example of FIGS. 3 and 4, the recording material is used. FIG. 5 shows a configuration for lifting up and down vertically. Here, the reason why the algorithm is described using a simplified configuration is that the description of the algorithm becomes complicated because a link mechanism is interposed in FIGS. 3 and 4. Therefore, a component 200 necessary for explaining the algorithm is selected, and a simplified model 200 is shown in FIG. Although the algorithm will be described using the configuration of FIG. 5, it is also possible to apply a similar algorithm to FIG. 3 and FIG. A method adapted to FIGS. 3 and 4 will be described later.

  Each configuration of FIG. 5 will be described. Reference numeral 206 denotes a stacking plate that is movable in the vertical direction and stacks recording materials. Connected to the center of the stacking plate 206 is a stacking plate arm 205 that vertically lifts the stacking plate 206 toward a feed roller (not shown). The stacking plate arm 205 is connected to a lifter rack 202 as a supporting means via a spring 204. The stacking plate arm 205, the spring 204, and the lifter rack 202 constitute lifter means for moving the stacking plate 206 vertically.

  Further, a detection lever 207 and a detection photo interrupter 208 are provided for detecting the recording material S lifted by the lifter means. A cassette gear 201 functions as a pinion gear for the lifter rack 202. The image forming apparatus main body is provided with a drive transmission gear (not shown), which receives the drive from the stepping motor 122 and transmits the drive to the lifter rack 202.

  FIG. 5A shows an initial state in which the lift-down is performed. When the drive is transmitted from the stepping motor 217, the lifter rack 202 is driven and the lift-up is started. FIG. 5B shows a state immediately before the stacking plate 206 is lifted up, and FIG. 5C shows a state in which the recording material S is detected by the detection photo interrupter 208 due to the lift-up. Show.

[Calculation of lift operation amount]
Next, the lift operation amount at the time of lift-up and lift-down will be described. As shown in FIG. 5, the lift operation amount is the displacement amount X0 from the start of driving of the stepping motor 122 to the end thereof, and the displacement amount from the start of driving of the stepping motor 122 to the balanced state of the spring 204. Xt is constituted by a displacement amount Xm from when the balanced state is reached until the recording material S is detected by the detection photo interrupter 208. From these, when the lift operation amount Xn is obtained,
Xn = X0−Xt + Xm (1)
Can be calculated.

The amount of displacement Xt from when the stepping motor 122 starts to rotate until the spring 204 reaches a balanced state is the weight M0 of the stacking plate 206, the weight Mp of the recording material per sheet, the number Pn of recording materials, gravity From acceleration g and spring constant k, Xt = (Mp × Pn + M0) × g ÷ k (2)
Can be calculated. Equation (2) is
(Mp × Pn + M0) ÷ g = k × Xt (3)
And can be deformed.

The amount of displacement Xm until the paper surface reaches the paper surface detection sensor position after reaching the balanced state is the position Hs from the bottom of the cassette until the detection lever 207 does not shield the detection photo interrupter 208, and the recording material thickness per sheet. From the height Hp and the number Pn of recording materials,
Xm = (Hs−Hp × Pn) (4)
And can be calculated.

When the lift operation amount is obtained from the above explanation,
Xn = X0− (Mp × Pn + M0) × g ÷ k− (Hs−Hp × Pn) (5)
And can be calculated. It is assumed that the recording material weight Mp per sheet, the recording material thickness Hp per sheet, and the number Pn of recording materials are variables, and other parameters are constants.

[Calculation of remaining recording material]
A method of obtaining the number Pn of recording materials based on the lift operation amount described above will be described with reference to FIG. As in the case described with reference to FIG. 5, the recording material weight Mp per sheet, the recording material thickness Hp per sheet, and the number Pn of recording materials are used.

  FIG. 6A shows a state in which the recording material S is detected by the photo interrupter 208 for detection after lifting the stacking plate 206 in a state where the number P1 of recording materials is stacked. At this time, the lift operation amount is X1. FIG. 6B shows a state in which the number of stacked sheets is reduced by a predetermined number from the number P1 of recording materials stacked in FIG. 6A, that is, a state in which (P1-P2) is decreased. In FIG. 6C, the number of stacked sheets is reduced by (P1-P2), the stacking plate 206 in a state where the number of recording materials P2 is stacked is lifted, and the recording material S is detected by the photo interrupter 208 for detection. The detected state is shown. At this time, the lift operation amount is X2.

  When (P1-P2) recording materials are reduced from the recording materials S stacked in FIG. 6A, the upper surface of the recording materials stacked is (Hp-Mp ×) as shown in FIG. 6B. g ÷ k) × (P1-P2). This is because the height of the entire recording material loaded is reduced by Hp × (P1−P2), and the upper surface of the recording material is also lowered. However, since the weight of the entire recording material is reduced by Mp × (P1−P2), the spring is reduced by (Mp × g ÷ k) × (P1−P2), and the upper surface of the recording material is increased. Considering these effects, the upper surface of the recording material is lowered by (Hp−Mp × g ÷ k) × (P1−P2).

As shown in FIG. 6C, the lift operation amount when the number P2 of recording materials is stacked is X2. The amount of displacement (Hp−Mp × g ÷ k) × (P1−P2) on the upper surface of the recording material and the amount of change in the lift operation amount (X1−X2) due to the decrease in the number of recording materials from P1 to P2 are the same value. is there. From this, the relational expression of the lift operation amount based on the recording material weight Mp per sheet, the recording material thickness Hp per sheet, and the number Pn of recording materials is
(X1−X2) = (Hp−Mp × g ÷ k) × (P1−P2) (5)
And can be calculated.

Based on the equation (5), the remaining amount of the recording material is obtained by the following procedure. When the number of recording materials loaded on the stacking plate 206 is different and the number of recording materials is known, the lift operation amount Xn for each number of recording materials is measured. The first measurement value is X1, the second measurement value is X2, and the difference between the first and second recording material numbers Pn is ΔP12. From this, the lift operation amounts X1 and X2 are respectively
X1 = X0− (Mp × (Pn−ΔP12) + M0) × g ÷ k− (Hs−Hp × (Pn−ΔP12)) (6)
X2 = X0− (Mp × Pn + M0) × g ÷ k− (Hs−Hp × Pn) (7)
And can be calculated.

Using the relational expression (5) of the lift operation amount (X1−X2) and the relational expressions (6) and (7) of the lift operation amounts X1 and X2, the remaining amount P2 of the recording material is
P2 = ΔP12 × (X2−X0 + (M0 × g ÷ k) + Hs) ÷ (X2−X1) (8)
And can be calculated.

To further generalize this,
Pn = ΔPn_n−1 × (Xn−X0 + (M0 × g ÷ k) + Hs) ÷ (Xn−Xn−1) (9)
And can be calculated.

[Recording material remaining amount detection method]
A method of detecting the number of recording materials will be described with reference to the flowchart of FIG. Here, for convenience of explanation, it is assumed that the stacking plate 206 is in the lowest position in the initial state, but the initial position is not limited to the lowest position. Here, the position of the stacking plate 206 is changed by driving the stepping motor 122. That is, the number of driving steps of the stepping motor 122 corresponds to the displacement amount of the stacking plate 206. Therefore, the displacement amount of the stacking plate 206 can be replaced with the number of steps of the stepping motor 122.

  In step S701, when the laser beam printer is turned on, the CPU 115 starts a lift-up operation. In S702, when the lift-up operation is completed, the CPU 115 acquires the step number T1 of the stepping motor 122 and stores it in the RAM 117 as the lift operation amount X1. In step S <b> 703, the CPU 115 lifts down the stacked loading plate 206. In step S704, the CPU 115 waits until receiving a print instruction.

  In step S705, when the CPU 115 receives the print instruction, the CPU 115 performs the lift-up operation again. In S706, the CPU 115 performs a printing operation when the lift-up operation is completed. In step S707, the CPU 115 counts the number of printed sheets V on which printing has been performed. In step S <b> 708, the CPU 115 repeats the printing operation and the number of printed sheets until all printing instructed by the printing instruction is completed.

  In step S709, the CPU 115 determines whether or not the number of printed sheets V is equal to or greater than the lift operation amount detectable sheet number V0. If the number of printed sheets V is less than the lift operation amount detectable sheet number V0, a lift-down operation is performed and the process proceeds to S703. If the number of printed sheets V is greater than or equal to the lift operation amount detectable sheet number V0, the CPU 115 holds the number of printed sheets V as ΔP12 in the RAM 117 in S710. In S711, the CPU 115 performs a lift-down operation. In S712, when the lift-down operation is completed, the CPU 115 acquires the step number U1 of the stepping motor 122 and stores it in the RAM 117 as the lift operation amount X2.

  In step S713, the CPU 115 calculates the number Pn of recording materials according to the equation (9) using the lift operation amounts X1 and X2 and the number of printed sheets ΔP12 held in the RAM 117. In step S <b> 714, the CPU 115 displays the calculated number Pn of recording materials on the display unit 112. In step S715, the CPU 115 clears the count of the number of printed sheets V and ends the process.

  Up to this point, the method of detecting the number Pn of recording materials using the simplified model 200 shown in FIGS. 5 and 6 has been described. However, the supply of the method of lifting up obliquely shown in FIGS. It is also possible to detect the number Pn of recording materials in the feeding unit 20. The detection of the number Pn of recording materials in the feeding unit 20 that lifts obliquely will be described. Unlike the simplified model 200, the feeding unit 20 has a link mechanism, and the stacking plate 31 rotates around the rotation fulcrum 31a to realize a lifting operation. Therefore, there is a possibility that the lift operation amount expression cannot be obtained as a primary expression such as Expression (4). Therefore, a formula for the lift operation amount in the feeding unit 20 is set in advance in the development stage. When the lift operation amount is a linear expression, the number Pn of recording materials can be obtained using Expression (9).

  If the set lift operation amount equation is not a linear equation, the number Pn of recording materials can be obtained from the correspondence table between the lift operation amount and the lift operation amount equation shown in FIG. 8 and the number Pn of recording materials. . The lift operation amounts X1 and X2 shown in FIG. 8 are the above-described first and second lift operation amounts. ΔP12 indicates the number of recording materials printed from the first measurement to the second measurement of the lift operation amount. From the expression (X1−X2) ÷ ΔP12 indicating the inclination of the lift operation amount and the lift operation amount expression, the number Pn of recording materials can be obtained.

  Thus, the lift operation amounts X1 and X2 and the number of printed sheets ΔP12 are measured, and the remaining recording material information can be obtained from the stacked recording material number correspondence table held in the ROM 116. Further, when the lift operation amount X2 is not shown in the drawing, (X1−X2) ÷ ΔP12, the recording material remaining amount information can be obtained by linearly complementing each item.

  As described above, even in the case where an elastic member is provided as a configuration of the stacking unit on which the recording material is loaded, the remaining amount of the recording material can be accurately detected based on the lift operation amount and the state of the elastic member. Therefore, if it is possible to accurately detect that the loading amount of the recording material has decreased, it is possible to accurately perform control such as notifying the user that there is no paper or stopping image formation when the recording material runs out.

DESCRIPTION OF SYMBOLS 20 Feeding part 21 Feeding roller 22 Separation roller 23 Paper surface detection lever 24 Photo interrupter 30 Paper feed cassette 31 Loading plate 32 Paper surface detection photo interrupter 36 Pressure spring

Claims (8)

Loading means for loading recording materials;
Driving means for driving the loading means;
An elastic member for transmitting a driving force from the driving means to the loading means;
Detecting means for detecting the recording material stacked on the stacking means by driving the stacking means with a driving force from the driving means;
A first operating amount when the loading unit in a state where the recording material is loaded is driven to a position where the detection unit detects the recording material, and after feeding a predetermined number of recording materials, The number of sheets of recording material loaded on the stacking unit is calculated using the second operation amount when the stacking unit in the stacked state is driven to a position where the detection unit detects the recording material. And a recording material loading device.   The recording material stacking apparatus according to claim 1, wherein the control unit raises the stacking unit by the driving unit until the recording unit loaded on the stacking unit is detected by the detection unit. The control means sets the second number of recording materials to P2, the operation amount from the start of the drive means to the end thereof being X0, the first operation amount is X1, the second operation amount is X2, The difference between the first number and the second number is ΔP12, the weight of the loading plate is M0, the acceleration of gravity is g, the spring constant of the elastic member is k, and the height until the recording material is detected by the detecting means Let Hs be
P2 = ΔP12 × (X2−X0 + (M0 × g ÷ k) + Hs) ÷ (X2−X1)
The recording material stacking apparatus according to claim 1, wherein the second number of the recording materials is calculated by: Storage means for storing a correspondence table between the operation amount by the driving means and the number of recording materials stacked on the stacking means;
When the stacking means is configured to move up and down obliquely, the control means is configured to use the first operation amount, the second operation amount, and a correspondence table stored in the storage means according to the correspondence table stored in the storage means. The recording material stacking apparatus according to claim 1, wherein the second number of recording materials stacked on the recording medium is calculated. Loading means for loading recording materials;
Driving means for driving the loading means;
An elastic member for transmitting a driving force from the driving means to the loading means;
Detecting means for detecting the recording material stacked on the stacking means by driving the stacking means with a driving force from the driving means;
A first operating amount when the loading unit in a state where the recording material is loaded is driven to a position where the detection unit detects the recording material, and after feeding a predetermined number of recording materials, The number of sheets of recording material loaded on the stacking unit is calculated using the second operation amount when the stacking unit in the stacked state is driven to a position where the detection unit detects the recording material. And an image forming apparatus.   The image forming apparatus according to claim 5, wherein the control unit raises the stacking unit by the driving unit until a recording material stacked on the stacking unit is detected by the detection unit. The control means sets the second number of recording materials to P2, the operation amount from the start of the drive means to the end thereof being X0, the first operation amount is X1, the second operation amount is X2, The difference between the first number and the second number is ΔP12, the weight of the loading plate is M0, the acceleration of gravity is g, the spring constant of the elastic member is k, and the height until the recording material is detected by the detecting means Let Hs be
P2 = ΔP12 × (X2−X0 + (M0 × g ÷ k) + Hs) ÷ (X2−X1)
The image forming apparatus according to claim 5, wherein the second number of recording materials is calculated by: Storage means for storing a correspondence table between the operation amount by the driving means and the number of recording materials stacked on the stacking means;
When the stacking means is configured to move up and down obliquely, the control means is configured to use the first operation amount, the second operation amount, and a correspondence table stored in the storage means according to the correspondence table stored in the storage means. The image forming apparatus according to claim 5, wherein the second number of recording materials stacked on the printer is calculated.

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