JP2015212789A - Image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve usability by suppressing the occurrence of conveyance failure.SOLUTION: An image forming apparatus measures a reaching time required for a recording material to reach a predetermined position in a conveyance path from the supply of the recording material after detection of opening/closing of a cassette, and outputs information indicating the state of a regulation plate of the cassette according to a result of comparison between the measured reaching time and a threshold based on a reaching time measured before the detection of opening/closing of the cassette.

Description

  The present invention relates to an apparatus having a function of discriminating a state of a recording material in a stacking unit on which the recording material is loaded.

  Conventionally, the conveyance time from the start of the supply of the recording material in the supply device for supplying the recording material until the recording material reaches a predetermined position on the conveyance path is detected, and the conveyance speed of the recording material is controlled according to the detection result. In addition, a technique for determining a conveyance state of a recording material is known. For example, Patent Document 1 proposes a technique for controlling the conveyance speed of a recording material based on the difference between the conveyance time from the start of supply of the recording material to a predetermined position and the reference time.

Patent No. 4392939

  When a recording material conveyance failure occurs in the recording material supply device, it is necessary to stop the conveyance operation of the supply device and remove the recording material in which the conveyance failure has occurred. As a supply device, it is desirable to reduce the occurrence of such a conveyance failure of the recording material as much as possible. As a case where there is a relatively high possibility that a recording material conveyance failure will occur, there may be mentioned a stacking unit on which the recording material is loaded, for example, immediately after a cassette or tray on which the recording material is loaded. Here, it is known that the recording material may not be set correctly on the cassette or tray by the user immediately after the cassette or tray is attached or removed, so that the possibility of a conveyance failure is relatively high.

  An object of the present invention is to determine a state in which a recording material is stacked on a recording material stacking unit such as a cassette or a tray, thereby suppressing the occurrence of a conveyance failure and improving usability.

  In order to solve the above-described problem, an image forming apparatus according to the present application includes a stacking unit that stacks recording materials, a regulating unit that regulates a position of the recording material in the stacking unit, and a recording material stacked on the stacking unit. A feeding means for feeding; a detecting means for detecting opening / closing of the stacking means; and after the opening / closing of the stacking means is detected by the detecting means, the recording material is conveyed after the recording material is supplied by the supplying means. Measure the arrival time until reaching a predetermined position on the road, compare the measured arrival time with a threshold based on the arrival time measured before the detection means detects the opening and closing of the loading means, and according to the comparison result Control means for outputting information indicating the state of the restricting means.

  According to the present invention, it is possible to improve the usability by suppressing the occurrence of conveyance failure.

FIG. 6 is a diagram illustrating a relationship between a recording material arrival time and a threshold value in Examples 1 and 3; 1 is a configuration diagram of an image forming apparatus. FIG. 3 is a diagram illustrating a recording material position in a cassette according to the first exemplary embodiment. The block diagram which shows an example of a structure of a control part. 5 is a flowchart illustrating the operation of a control unit according to the first embodiment. FIG. 6 is a diagram illustrating a relationship between a recording material arrival time and a threshold value in Examples 2 and 3; FIG. 4 is a configuration diagram of a part of an image forming apparatus in Embodiments 2 and 3. FIG. 9 is a diagram illustrating a state of a recording material in a cassette according to the second embodiment. 9 is a flowchart illustrating the operation of a control unit according to the second embodiment. 10 is a flowchart illustrating the operation of a control unit according to the third embodiment. 1 is a diagram illustrating an example of an image forming system.

  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 claims, and all combinations of features described in the embodiments are not necessarily essential to the solution means of the invention.

  First, Example 1 will be described. In this embodiment, after the cassette as the recording material stacking section is attached / detached (opened / closed), the time from when the recording material is supplied to when it reaches the predetermined position on the transport path is detected. Based on the detected time, it is determined whether or not it is necessary to confirm the position of the regulation plate in the cassette.

(Description of configuration of image forming apparatus)
FIG. 2 shows an example of the configuration of the image forming apparatus 200. The operation of the image forming apparatus 200 is controlled by the controller 110. The controller 110 is equipped with a CPU 100 as an arithmetic processing unit. The recording material P is stacked on the cassette 218, supplied one by one by a paper feed roller 216 as a transport unit at a predetermined timing, and transported toward the photosensitive drum 206 by the transport rollers 214 and 215. The transport units (transport rollers 214 and 215) are driven by a transport motor 233 and a solenoid 234 described later. The supply unit 230 as a supply device includes a cassette 218 that is a stacking portion of the recording material P, a rear end regulating plate 219 that regulates the recording material in the cassette 218, a paper feed roller 216, and a transport roller 215. The presence or absence of the recording material P is detected by a sensor 213 that is installed in the conveyance path of the recording material P and detects the recording material P being conveyed. Further, the image forming apparatus 200 is provided with an open / close sensor 250 as a detection member for detecting opening / closing of the cassette 218, and detects opening / closing of the cassette 218. The CPU 100 measures the time from when the conveyance of the recording material P is started by the paper feed roller 216 until the leading edge of the recording material P reaches the sensor 213. The display panel 120 displays (notifies) information indicating the state of the image forming apparatus 200 such as printing, standby, and occurrence of conveyance failure. This display is a display for warning a user who uses the image forming apparatus.

  The image forming apparatus of this embodiment is an electrophotographic printer. The photosensitive drum 206 rotates in the direction of the arrow in the figure, and a charging voltage is applied to the charging roller 220 and a developing voltage is applied to the developing roller 204 at a predetermined timing. The photosensitive drum 206 is uniformly charged by the charging roller 220. A laser is emitted from the scanner unit 212 as an exposure unit at a predetermined timing. The laser emitted from the scanner unit 212 is applied to the photosensitive drum 206, and an electrostatic latent image is formed on the photosensitive drum 206. The toner container 202 is filled with toner. The developing roller 204 rotates to supply toner in the toner container 202 onto the photosensitive drum 206, and the electrostatic latent image is developed as a toner image. The transfer roller 205 is in contact with the photosensitive drum 206 to form a nip portion. The recording material P is nipped and conveyed. A transfer voltage having a polarity opposite to that of the toner is applied to the transfer roller 205, and the toner image on the photosensitive drum 206 is transferred to the recording material P. The recording material P to which the toner image has been transferred is heated and pressed by the fixing unit 210 as a fixing unit, and the toner image is fixed to the recording material P. The recording material P on which the toner image is fixed is discharged to the outside of the image forming apparatus 200 by the transport roller 211.

(Description of operation)
A characteristic operation of the present embodiment will be described. FIG. 4 is a block diagram illustrating an example of a configuration of a control unit by the CPU 100 that controls the conveyance of the recording material P in the image forming apparatus 200. First, the CPU 100 drives the transport motor 233 to rotate the transport roller 215. Thereafter, the solenoid 234 is driven to rotate the paper feed roller 216 once at a predetermined timing in accordance with an instruction to start image formation. The uppermost sheet of the recording material P pushed up in the cassette 218 comes into contact with the paper feed roller 216, and the paper feed roller 216 rotates, whereby the recording material P is separated and supplied one by one, and the transport roller 215 is fed. It is conveyed to. The recording material P is conveyed by the rotating conveyance roller 215 and further conveyed to the position of the sensor 213. When the leading edge of the recording material P reaches the sensor 213, the sensor 213 detects the leading edge of the recording material P. A detection signal from the sensor 213 is input to the CPU 100. The CPU 100 measures a time T (hereinafter, this time is referred to as an arrival time T) from when the solenoid 234 is turned on until the sensor 213 detects the leading edge of the recording material P, and stores it in the memory 101 as a storage unit. . In this embodiment, the memory 101 is a nonvolatile memory. The memory 101 stores an arrival time Tv (k) (k = 1, 2,..., N) for each conveyance, and an arrival time Tz (p) (p = 1, 2,. .., M) are provided (n and m are natural numbers). The arrival time T before the cassette 218 is opened and closed is stored as the arrival time Tv (k), and the arrival time T after the cassette 218 is opened and closed is stored as the arrival time Tz (p). The arrival time T in the m-th and subsequent transport operations after opening and closing of the cassette 218 is again stored in Tv (k).

  Next, a method for updating the storage of the arrival time Tv (k) will be described. At the beginning of the operation of the image forming apparatus 200, arrival times Tv (1) to Tv (n) from the first transport operation to the nth transport operation are stored. At the (n + 1) -th transport operation when the arrival times Tv (1) to Tv (n) are stored, the arrival time Tv (1) n times before is cleared, and the stored arrival time Tv ( 2) is rewritten (updated) to Tv (1). By rewriting in this way, Tv (k) = Tv (k + 1) is obtained, the (n + 1) th arrival time Tv (n + 1) is stored in Tv (n), and Tv (k) is updated. In this way, n Tv (k) including the latest arrival time T are always stored in the storage unit of the CPU 100. Then, the CPU 100 calculates a value obtained by averaging the arrival times Tv (k) for n times each time a plurality of recording materials P are conveyed and conveyed each time.

  Then, a threshold set based on the calculated Tv (ave) is stored in the storage unit of the CPU 100. The threshold setting method will be described later in detail. Even when all the arrival times Tv (1) to Tv (n) for n times are not stored, the average value Tv (ave) of the stored Tv (k) is calculated and based on Tv (ave). May be stored in the storage unit of the CPU 100. The value of n may be set as appropriate. In this embodiment, n = 5.

  Next, a method for storing the arrival time Tz (p) after opening / closing the cassette 218 will be described. When the opening / closing of the cassette 218 is detected by the CPU 100 based on the signal of the opening / closing sensor 250, the arrival time Tz (p) detected after opening / closing the cassette 218 stored in the storage unit of the CPU 100 is cleared. Then, m arrival times Tz (p) newly detected after opening / closing the cassette 218 are stored. Then, the CPU 100 uses the threshold set based on Tv (ave) at the end of the m-th transport operation after opening / closing the cassette 218 and the arrival time Tz (p) for m times newly detected after opening / closing the cassette 218. Compare the averaged values. Tz (P) is calculated by the following equation 2. In this embodiment, m = 5 was set. Note that n and m may be values that are not averaged with n = 1 and m = 1, respectively.

  Then, the calculated Tz (ave) is compared with a threshold value. Based on the comparison result, it is determined whether the conveyance of the recording material P is normal, whether the conveyance is defective, or whether the rear end regulating plate 219 of the recording material P needs to be readjusted. The determination method will be described later in detail.

  Then, Tv (n + 1) = Tz (m) is set when the transport operation after opening / closing the cassette 218 is the mth time. When the transport operation after opening / closing the cassette 218 exceeds the mth time, the storage of the arrival time Tz (p) detected after opening / closing the cassette 218 is terminated, and the update of the arrival time Tv (k) is resumed.

  Even when the image forming apparatus 200 is turned off, the state before the power is turned off is stored and held. Specifically, the number of transfer operations after the cassette 218 is opened, the arrival time Tv (k) for n times stored in the storage unit of the CPU 100, the arrival time Tz (p) for the number of transfer operations, and the threshold are cleared. It is held all the time.

  Next, a determination method of the CPU 100 will be described. The storage unit of the CPU 100 also stores a lower limit threshold Tf and an upper limit threshold Td for determining whether the conveyance of the recording material P is normal. The thresholds Tf and Td are values obtained by adding a margin to a value Tv (ave) obtained by averaging the arrival times Tv (k) for n times. Note that the threshold values Tf and Td may be based on the average value Tv (ave), or corrected by taking into account the operating status of the image forming apparatus 200, the type of the recording material P, the surrounding environment, and the like to the average value Tv (ave). It may be based on the value obtained. Further, it may be based on Tv (1) which is a value for one time just before the cassette 218 is opened and closed.

  As shown in FIG. 1, the CPU 100 conveys the recording material P based on the comparison between the arrival time Tz (ave) of the recording material P conveyed after opening and closing of the cassette 218 and the threshold values Tf to Td described above. Is in the range of normal operation. Specifically, in the comparison with the set threshold values Tf to Td, when Tf ≦ Tz (ave) ≦ Td, that is, the average arrival time is equal to or greater than the threshold (Tf or more) or less than the threshold (Td or less). Based on this, it is determined that the conveyance of the recording material P is normal. Further, the storage unit of the CPU 100 also stores a threshold value Te for determining whether or not a conveyance failure has occurred. The threshold value Te is set in consideration of at least the operating state of the image forming apparatus 200, the type of the recording material P, the size of the recording material P, or the conveyance speed. Furthermore, the diameters of the feeding roller 216 and the conveying roller 215 are set within an allowable range in which image formation can be performed even in a state where the recording material P slips (slip) due to a decrease in the diameter due to wear. As shown in FIG. 1, the CPU 100 determines whether the recording material P is conveyed based on the comparison between the arrival time Tz (ave) of the recording material P conveyed after opening and closing the cassette 218 and the threshold values Tf and Te described above. Judge whether it is within the range of normal operation. Specifically, in the comparison with the set threshold values Tf and Te, when the value is below Tf (Tz (ave) <Tf) or above Te (Te <Tz (ave)), an appropriate transport operation or image formation is performed. It is determined that the conveyance failure has occurred.

  FIG. 3 shows a state in which the recording material P is stacked on the cassette 218. Here, the premise of the stacked state of the recording material P for setting the threshold values Tf and Td is assumed that the recording material P is stacked in the normal position in the cassette 218 as shown in FIG. doing. The normal position is a state in which the end of the recording material P in the transport direction is stacked so that the front end regulating portion 240 of the cassette 218 substantially coincides with the transport direction. The rear end regulating plate 219 of the recording material P regulates the rear end of the recording material P with respect to the conveyance direction of the recording material P. Further, the lateral end regulating plates 231 and 232 of the recording material P regulate both ends in the direction orthogonal to the conveying direction of the recording material P, and according to the size of the recording material P loaded on the cassette 218, It can move in the orthogonal direction.

  On the other hand, as shown in FIG. 3B, the recording material P is moved from the normal position to the transport direction by moving the position of the rear end regulating plate 219 of the recording material P backward from the normal position with respect to the transport direction. There is a possibility of being loaded backward. The rear end regulating plate 219 is a member that can move in the transport direction according to the size of the recording material P in the transport direction. Therefore, when the recording material P is loaded by the user while being moved backward in the transport direction and the recording material P is not returned to the restricting position, the state shown in FIG. When the recording material P is transported in a state where it is stacked rearward with respect to the transport direction from the normal position in this way, the transport distance from the leading end of the recording material P to the registration sensor 213 is increased by ΔL in FIG. Therefore, the arrival time T becomes longer. Thus, depending on the distance of ΔL, the arrival time Tz (ave) becomes Td or more. In this case, image formation can be executed within the range of arrival time Tz (ave) ≦ Te. However, since the recording material P in the cassette 218 is not in the normal position, there is a possibility that a paper feeding failure or a conveyance failure may occur. .

  Thus, in the conveyance when the recording material P is stacked behind the normal position, the CPU 100 determines whether the rear end regulating plate 219 needs to be readjusted by executing the following control. Specifically, when the arrival time Tz (ave) of the recording material P conveyed after opening and closing of the cassette 218 has changed to a range of Td <Tz (ave) ≦ Te, the CPU 100 detects the trailing edge of the recording material P. It is determined that the readjustment of the regulation plate 219 is necessary.

  As described above, based on the result of comparison between the arrival time Tz (ave) of the recording material P conveyed after opening / closing the cassette 218 and the threshold values Tf, Td, Te, the recording material in the cassette after opening / closing the cassette 218 Capture changes in loading conditions. The feature of this embodiment is that the necessity of readjustment of the rear end regulating plate 219 is determined.

(Explanation of control by CPU)
Next, the conveyance operation by the CPU 100 of this embodiment will be described with reference to the flowchart of FIG. It is assumed that the CPU 100 recognizes the type and size of the recording material P by the time when the arrival time T is detected. In addition, it is assumed that the CPU 100 that is the main body that controls the conveyance of the recording material P is also controlled while recognizing the conveyance state of the recording material P. The CPU 100 executes the following control by a program stored in a ROM (not shown) in the CPU.

  The CPU 100 determines whether or not the recording material P is transported immediately after the cassette 218 is opened and closed (S101). If the cassette 218 is immediately after the cassette 218 is opened and closed, the CPU 100 arrives after the cassette 218 stored in the memory 101 is opened and closed. Tz (p) is cleared (S102). On the other hand, if it is not immediately after opening / closing of the cassette 218, the arrival time Tz (p) is not cleared. Then, the CPU 100 starts measuring the arrival time T from the instruction to supply the recording material P (S103). Then, it is monitored whether the arrival time (monitoring time) is within a threshold time (S117). Monitoring is continued until the recording material P reaches the sensor 213 (S104). If the recording material P does not reach the sensor 213 within the threshold time, it is determined that the feeding is delayed (S118) and the operation is finished. To do.

  Whether the recording material P reaches the sensor 213 and is the first to m-th (1 ≦ p ≦ m) transport operation after the cassette 218 is opened or closed, and the transport operation beyond the m-th time after the cassette 218 is opened or closed Is determined (S105). In the case of the conveyance operation exceeding the mth time after the cassette 218 is opened and closed, as described above, the CPU 100 stores the arrival time Tv (k) of the memory 101 so that the latest n arrival times Tv (k) are stored. ) Is updated and stored (S108). Thereafter, an average value Tv (ave) and threshold values Tf and Td set based on the average value Tv (ave) are calculated from the latest n arrival times Tv (k), and Tv (ave) and Tf And Td is memorize | stored in the memory 101 (S109), and operation | movement is complete | finished.

  On the other hand, when the cassette 218 is in the first to m-th transport operation after opening / closing (S105), it is determined whether it is the m-th (p = m) transport operation after opening / closing the cassette 218 (S106). If p = m is not satisfied (if p <m), the CPU 100 stores the arrival time Tz (p) after opening / closing of the cassette 218 (S110). If p = m, the arrival time Tz (p) (p = 1, 2,..., m−1) after opening / closing of the cassette 218 stored in the CPU 100 and the newly detected mth arrival time Tz ( The average value Tz (ave) is calculated from m) (S111). Then, the average value Tz (ave) is compared with the threshold values Tf to Td stored in the memory 101 (S112). When the arrival time Tz (ave) after opening and closing of the cassette 218 is Tf ≦ Tz (ave) ≦ Td, it is determined as normal. Then, the process of Tv (n + 1) = Tz (m) is performed (S107), the above-described operations (S108) to (S109) are performed, and the process ends.

  Next, when the arrival time Tz (ave) is not Tf ≦ Tz (ave) ≦ Td in (S112), it is determined whether Td <Tz (ave) ≦ Te (S113). If Td <Tz (ave) ≦ Te, the conveyance time of the recording material P is within an allowable range, but the position of the recording material P rear end regulating plate 219 in the cassette 218 may be shifted from the normal position. It is determined that there is (S114). Then, after the printing operation (image forming operation) is completed, the CPU 100 outputs information indicating that it is necessary to confirm the position of the recording material P rear end regulating plate 219 in the cassette 218 via the user interface such as the display panel 120. Then, the user is warned (S115). On the other hand, if the arrival time Tz (ave) after opening / closing the cassette 218 is not Td <Tz (ave) ≦ Te, that is, if Tz (ave) <Tf or Te <Tz (ave), it is determined that the conveyance is defective. Then, the operation is finished (S116).

  Even if different recording material P sizes are stacked before and after the cassette 218 is opened and closed, the sensor arrival time T does not change. Therefore, even if different recording material P sizes are loaded before and after the cassette 218 is opened and closed. The same operation as described above may be performed.

  Further, when the arrival time T is compared with the threshold value, it may be determined including the threshold value or may be determined including the threshold value. In other words, the inequality sign (<,>) and the inequality sign with an equal sign (≦, ≧) used in the judgment formula may be used depending on the situation.

  Further, the storage method in the memory 101 described above is the arrival time Tv (n) before the cassette 218 is opened and closed, the arrival time Tz (m) until the mth transport operation after the cassette 218 is opened and closed, and after the mth time. The arrival time Tv (n) before opening and closing of the cassette 218 was stored. However, the storage method is not limited to this method, and for example, the following method may be used. (1) A method of storing the arrival time T once before and after the cassette 218 is opened and closed. (2) A method of storing the arrival time Tv (n) only before the cassette 218 is opened and closed. (3) The arrival time Tz (m) is continuously updated after the mth time, and when the next cassette 218 is opened and closed, the arrival time Tz (m) is used as data before the cassette 218 is opened and closed. A method of newly storing the data after opening / closing the cassette 218.

  As described above, according to the present embodiment, immediately after opening / closing of the cassette 218 that is highly likely to cause a conveyance failure, the arrival time Tz (ave) after opening / closing of the cassette is compared with a threshold value. Thereby, the state of the recording material P in the cassette after opening and closing the cassette can be determined. Therefore, even in a situation where the position of the recording material P in the cassette 218 is shifted rearward with respect to the transport direction, it is possible to avoid a transport failure in advance.

  Regarding the image forming apparatus 200 in this embodiment, the same parts as those described in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

(Overview)
In this embodiment, the average value Tx (ab) (ave) of the arrival time differences Tx (ab) (p) of the sensors 213a and 213b, which are the second detectors, is opened and closed after the cassette 218 is opened and closed. Specifically, when the average value T (ab) (ave) of the arrival time difference T (ab) (k) is outside the range of the threshold set based on the average value T (ab), the regulating member in the cassette 218 It is possible to warn the user that confirmation of the position of is necessary.

(Description of configuration of image forming apparatus)
FIG. 7 is a view of the conveyance path near the conveyance roller 214 and the registration sensor 213 as viewed from above the image forming apparatus 200. The presence / absence of the recording material P and the skew state are detected by sensors 213a and 213b arranged perpendicularly to the left and right of the transport direction upstream of the transport roller 214. The CPU 100 measures the arrival times of the sensors 213a and 213b, which are the second detection units, after the conveyance of the recording material P is started by the feeding roller 216.

(Description of operation)
The process from the start of the feeding operation to the conveyance to the sensors 213a and 213b is the same as that of the first embodiment. Thereafter, when the recording material P reaches the registration sensors 213a and 213b, the registration sensors 213a and 213b detect the leading edge of the recording material P. Thereby, the CPU 100 measures the arrival time Ta to the sensor 213a and the arrival time Tb to the sensor 213b. Then, an absolute value | Ta−Tb | (hereinafter, referred to as arrival time difference T (ab)) of the difference between the arrival time Ta and the arrival time Tb is calculated and stored in the memory 101. The arrival time difference T (a−b) indicates the skew state of the conveyed recording material P. Similar to the first embodiment, each time the recording material P is conveyed, the memory 101 stores an area for storing the arrival time difference T (ab) (k) and the arrival time difference Tx (a after opening / closing the cassette 218. -B) An area for storing (p) is provided. The arrival time T before the cassette 218 is opened and closed is the arrival time difference T (ab) (k), and the arrival time difference T (ab) after the cassette 218 is opened and closed is the arrival time difference Tx (ab). Stored as (p). In addition, after the cassette 218 is opened and closed, the arrival time difference T (ab) in the m-th and subsequent transport operations is stored again in T (ab) (k). Then, the CPU 100 conveys a plurality of recording materials P, and each time the recording material P is conveyed, the CPU 100 calculates a value T (ab) (ave) obtained by averaging the arrival time differences T (ab) (k) for n times as follows. Calculate with Equation 3

  Then, a threshold value set based on the calculated T (ab) (ave) is stored in the memory 101. The threshold setting method will be described later in detail. It is also assumed that all the arrival time differences T (ab) (1) to T (ab) (n) for n times are not stored. In that case, the average value T (ab) (ave) of the stored T (ab) (k) is calculated, and the threshold value set based on T (ab) (ave) is calculated. You may memorize | store in the memory 101. FIG.

  When the opening / closing of the cassette 218 is detected, the CPU 100 clears the arrival time difference Tx (ab) (p) detected after the opening / closing of the cassette 218 stored in the memory 101. Then, the arrival time difference Tx (ab) (p) for m times newly detected after opening / closing of the cassette 218 is stored. At the end of the m-th transport operation after opening / closing of the cassette 218, the CPU 100 calculates a value Tx (ave) obtained by averaging the arrival time differences Tx (ab) (p) for m times newly detected after opening / closing of the cassette 218 as follows: Calculated using Equation 4. And it compares with the threshold value set based on calculated Tx (ave) and T (ab) (ave). The above n and m may be n = 1 and m = 1, respectively.

  Then, according to the comparison result, whether or not the conveyance of the recording material P is normal, whether or not a conveyance failure has occurred, whether the horizontal end regulating plates 231 and 232 and the rear end regulating plate 219 need to be readjusted. Judge whether. The determination method will be described in detail later.

  Then, when the transport operation after opening and closing the cassette 218 is the mth time, T (ab) (n + 1) = Tx (ab) (m). When the conveyance operation after opening / closing the cassette 218 exceeds m times, the storage of the arrival time difference Tx (ab) (p) detected after opening / closing the cassette 218 is terminated, and the arrival time difference T (ab) (k) ) Restart update.

  Even when the power of the image forming apparatus 200 is turned off, the state before the power is turned off is stored and held. Specifically, the number of transport operations after the cassette 218 is opened and closed, the arrival time difference T (ab) (k) stored in the memory 101, and the arrival time difference Tx (ab) (x) (m). p) and the threshold are not cleared but are retained.

  Next, a determination method of the CPU 100 will be described. The memory 101 also stores an upper limit threshold Tg for determining whether or not the conveyance of the recording material P is normal. The threshold value Tg is a value obtained by adding a margin to a value T (ab) (ave) obtained by averaging n arrival time differences T (ab) (k). The threshold value Tg may be the average value T (ab) (ave) itself, or the average value T (ab) (ave) may include the operating status of the image forming apparatus 200, the type of recording material P, and the surroundings. It may be based on a value corrected in consideration of the environment or the like. Further, it may be based on T (a−b) (1) which is a value for one time just before the cassette 218 is opened and closed.

  As shown in FIG. 6, the CPU 100 determines whether or not the recording material P is based on the comparison result between the arrival time difference Tx (ab) (ave) of the recording material P conveyed after opening and closing of the cassette 218 and the above-described threshold value Tg. It is determined whether the conveyance state is within a normal operation range. Specifically, in the comparison with the set threshold value Tg, if 0 ≦ Tx (ab) (ave) ≦ Tg, it is determined that the conveyance of the recording material P is normal. Furthermore, the memory 101 also stores a threshold value Th for determining whether or not a conveyance failure has occurred. The threshold value Th is set to an allowable range in which image formation can be performed in consideration of at least the operating state of the image forming apparatus 200, the type of the recording material P, the size of the recording material P, the conveyance speed thereof, and the like. As shown in FIG. 6, the CPU 100 determines whether or not the recording material P is based on the comparison result between the arrival time difference Tx (ab) (ave) of the recording material P conveyed after the cassette 218 is opened and closed and the threshold value Th described above. It is determined whether or not the conveyance state is within a normal operation range. Specifically, if the comparison with the set threshold value Th exceeds Th (Th <Tx (ab) (ave)), it is determined that an appropriate conveyance operation or image formation cannot be performed, and conveyance failure Is determined to have occurred.

  FIG. 8 shows a state in which the recording material P is stacked on the cassette 218. Here, the premise of the state of the recording material P for setting the threshold Tg is assumed to be a state in which the recording material P is stacked at a normal position in the cassette 218 as shown in FIG. ing. In the normal position state, the leading end of the recording material P coincides with the leading end restricting portion 240 of the leading end cassette 218 and the lateral end of the recording material P coincides with the lateral end restricting plates 231 and 232 with respect to the conveyance direction of the recording material P. Is in a state of being loaded. The rear end regulating plate 219 regulates the rear end of the recording material P with respect to the conveyance direction of the recording material P, and the lateral end regulating plates 231 and 232 regulate the position in the direction perpendicular to the conveyance direction of the recording material P. Yes. Each regulating plate can be moved in accordance with the size of the recording material P loaded on the cassette 218.

  As shown in FIG. 8B, the recording material P can be stacked at a position shifted obliquely with respect to the normal position in a state where the positions of the lateral end regulating plates 231 and 232 and the rear end regulating plate 219 are moved. There is sex. When the recording material P is transported in a state where the recording material P is stacked at a position obliquely deviated from the normal position, the transport distance from the leading end of the recording material P to the sensor 213a is equal to ΔLa in FIG. 8B. become longer. Therefore, the arrival time Ta is also increased. Thus, the arrival time difference Tx (ab) (ave) between the arrival time Ta to the sensor 213a and the arrival time Tb to the sensor 213b becomes equal to or greater than the threshold Tg depending on the distance of ΔLa. In this case, if the arrival time difference Tx (ab) (ave) ≦ Th is within the range, image formation can be performed, but the recording material P in the cassette 218 is not in the normal position, so that a conveyance failure may occur. There is. As described above, in the conveyance when the recording material P is placed at a position that is obliquely shifted from the normal position, the CPU 100 executes the following control to control the lateral end regulating plates 231 and 232 and the rear end. It is determined whether or not readjustment of the restriction plate 219 is necessary. Specifically, when the arrival time difference Tx (ab) (ave) is Tg <Tx (ab) (ave) ≦ Th, the CPU 100 controls the horizontal end regulating plates 231 and 232 and the rear end regulating plate 219. It is determined that readjustment is necessary.

  As described above, the change after opening / closing of the cassette 218 is captured by the comparison result between the arrival time difference Tx (ab) (ave) of the recording material P conveyed after opening / closing of the cassette 218 and the threshold values Tg and Th. Thus, the feature of this embodiment is that the necessity of readjustment of the lateral end regulating plates 231 and 232 and the rear end regulating plate 219 is determined.

(Description of control of conveyance operation by CPU)
Next, the conveying operation by the CPU 100 of this embodiment will be described with reference to the flowchart of FIG. In addition, the same code | symbol is attached | subjected to the same function as FIG. 5, and description is abbreviate | omitted. The general sequence is the same as the flowchart of FIG. 5, and the functions of S207, S208, S209, S210, S211, S212, and S213 are different. In this embodiment as well, the CPU 100 executes the following control by a program stored in a ROM (not shown) in the CPU.

  The recording material P reaches the sensor 213 (213a and 213b), and whether it is the first to m-th (1 ≦ p ≦ m) transport operation after the cassette 218 is opened or closed, exceeds the m-th time after the cassette 218 is opened or closed. It is determined whether or not it is a transport operation (S105). In the case of the transfer operation exceeding the mth time after the cassette 218 is opened and closed, an arrival time difference T (ab) (k) between the latest n times of arrival time Ta and arrival time Tb is calculated. Then, the arrival time difference T (ab) (k) in the memory 101 is updated and stored so that the arrival time difference T (ab) (k) is stored (S208). Thereafter, a threshold value set based on the average value T (ab) (ave) and the average value T (ab) (ave) from the latest n arrival time differences T (ab) (k). Tg is calculated. Then, T (ab) (ave) and Tg are stored in the memory 101 (S209), and the operation is terminated.

  On the other hand, when the cassette 218 is in the first to m-th transport operation after opening / closing (S105), it is determined whether or not it is the m-th (p = m) transport operation after opening / closing the cassette 218 (S106). If p = m is not satisfied (if p <m), the arrival time difference Tx (ab) (p) after opening / closing the cassette 218 is calculated, and the arrival time difference Tx (ab) after opening / closing the cassette 218 is calculated. ) (P) is stored in the memory 101 (S210). If p = m, the arrival time difference Tx (ab) (p) (p = 1, 2,..., m−1) after opening / closing of the cassette 218 stored in the memory 101 and the mth arrival time difference An average value Tx (ab) (ave) is calculated from Tx (ab) (m) (S211). Then, the average value Tx (ab) (ave) is compared with the threshold value Tg stored in the memory 101 (S212). When the arrival time difference Tx (ab) (ave) after opening / closing the cassette 218 is 0 ≦ Tx (ab) (ave) ≦ Tg, it is determined as normal. Then, the process of T (ab) (n + 1) = Tx (ab) (m) is performed (S207), the above-described operations (S208) to (S209) are performed, and the process ends.

  Next, when the arrival time difference Tx (ab) (ave) after opening / closing of the cassette 218 is not 0 ≦ Tx (ab) (ave) ≦ Tg in (S212), Tg <Tx ( a−b) It is determined whether (ave) ≦ Th (S213). The subsequent operation is the same as that described with reference to FIG.

  Further, when the arrival time T and the threshold value are compared, the determination may be made including the threshold value or may be made including the threshold value. In other words, the inequality sign (<,>) and the inequality sign with an equal sign (≦, ≧) used in the judgment formula may be used depending on the situation.

  As described above, according to the present embodiment, the threshold value is compared with the arrival time difference Tx (ab) (ave) after opening / closing of the cassette immediately after opening / closing of the cassette 218 which is highly likely to cause a conveyance failure. Thereby, the state of the recording material P in the cassette after the cassette 218 is opened and closed can be determined. Therefore, even when the position where the recording material P is placed in the cassette 218 is obliquely shifted with respect to the transport direction, it is possible to avoid the occurrence of transport failure.

  In the image forming apparatus 200 according to the present embodiment, the same parts as those in the first and second embodiments are denoted by the same reference numerals, and the description thereof is omitted.

(Overview)
In this embodiment, Ts (p) = (Ta (p) + Tb (p)) / 2 calculated from arrival times Ta (p) and Tb (p) of the sensors 213a and 213b, which are detection units after the cassette 218 is opened and closed. Average value Ts (ave) is used. It is determined whether or not the average value Ts (ave) is out of the range of the threshold set based on the average value Tr (ave) of the arrival time Tr (k). Further, an average value Tx (ab) (ave) of arrival time differences Tx (ab) (p) of the sensors 213a and 213b, which are detection units after the cassette 218 is opened and closed, is calculated. And it is judged whether it is outside the range of the threshold set up based on average value T (ab) (ave) of arrival time difference T (ab) (k) computed. Then, it is possible to warn the user that it is necessary to confirm the positions of the lateral end regulating plates 231 and 232 and the rear end regulating plate 219 which are regulating members in the cassette 218.

(Description of configuration of image forming apparatus)
Since the configuration of the image forming apparatus is the same as that of the second embodiment, the description thereof is omitted.

(Description of operation)
From the start of the paper feeding operation, the sensors 213a and 213b detect the leading edge of the recording material P, and until the arrival time Ta to the sensor 213a and the arrival time Tb to the sensor 213b are measured, the same as in the second embodiment. It is. Thereafter, a center arrival time Tr = (Ta + Tb) / 2 (hereinafter referred to as arrival time Tr) between the arrival time Ta and the arrival time Tb is calculated and stored in the memory 101. Similar to the first and second embodiments, the memory 101 stores an area for storing the arrival time Tr (k) and the arrival time difference T (ab) (k) for each conveyance of the recording material P, and the cassette 218. An area for storing the arrival time Ts (p) after opening and closing and the arrival time difference Tx (ab) (p) is provided. The arrival time T until the cassette 218 is opened and closed is stored as the arrival time Tr (k), and the arrival time difference T (ab) is stored as the arrival time difference T (ab) (k). Further, the arrival time T after the cassette 218 is opened and closed is stored as the arrival time Ts (p), and the arrival time difference T (ab) is stored as the arrival time difference Tx (ab) (p). The arrival time T in the m-th and subsequent transport operations after opening / closing of the cassette 218 is again stored in Tr (k), and the arrival time difference T (ab) is again stored in T (ab) (k).

  Then, for each conveyance of the recording material P, the CPU 100 calculates a value Tr (ave) obtained by averaging the arrival times Tr (k) for n times according to the following Expression 5.

  Then, a value T (ab) (ave) obtained by averaging Tr (ave) and arrival time difference T (ab) (k) by the same operation as in the second embodiment is calculated, and Tr (ave) and The threshold value set based on T (ab) (ave) is stored in the memory 101. The threshold setting method will be described in detail later.

  Similarly, the arrival time Ts (p) = (Ta (p) + Tb (p)) / 2 (hereinafter referred to as arrival time Ts) and the arrival time difference Tx (ab) (p) after opening / closing the cassette 218 Stored in the memory 101.

  When the opening / closing of the cassette 218 is detected, the arrival time Ta stored in the memory 101 and the center arrival time Ts (p) = (Ta (p) + Tb (p)) / 2 of the arrival time Tb (hereinafter, the arrival time) The time difference Tx (ab) (p) is cleared. Then, the m arrival times Ta and the center arrival time Ts (p) = (Ta (p) + Tb (p)) / 2 newly detected after opening and closing of the cassette 218 and the arrival time difference Tx (ab) ) (P) is stored.

  The CPU 100 sets a threshold based on Tv (ave) and T (ab) (ave) at the end of the m-th transport operation after the cassette 218 is opened and closed. Further, a value Ts (ave) obtained by averaging the arrival times Ts (p) for m times newly detected after opening / closing of the cassette 218 is calculated by the following equation (6).

  Then, Ts (ave) and the value Tx (ab) (ave) = average value of the arrival time differences Tx (ab) (p) = the values calculated by the above-described Expression 3 are compared. According to the comparison result, whether or not the recording material P is conveyed normally, whether or not a conveyance failure has occurred, whether or not the horizontal end regulating plates 231 and 232 and the rear end regulating plate 219 need to be readjusted. to decide. The determination method will be described in detail later.

  Then, when the transport operation after opening and closing the cassette 218 is the mth time, Tr (n + 1) = Ts (m) and T (ab) (n + 1) = Tx (ab) (m) are set. If the transport operation after opening / closing the cassette 218 exceeds m times, the storage of the arrival times Ts (p) and Tx (ab) (p) detected after opening / closing the cassette 218 is terminated and reached again. The updating of the times Tr (k) and T (ab) (k) is resumed.

  Next, a determination method of the CPU 100 will be described. In the first embodiment, the arrival time for n times detected before opening and closing of the cassette 218 is Tv (n). However, in the third embodiment, the arrival time for k times detected before opening and closing of the cassette 218 is Tr (k). The discrimination operation is performed.

  In Example 1, the arrival time for m times detected after opening / closing of the cassette 218 is Tz (m). However, in this Example 3, the arrival time for p times detected after opening / closing of the cassette 218 is Ts (p ) And a discrimination operation is performed. Since operations other than those described above are the same as those in the first and second embodiments, a description thereof will be omitted.

  Before and after the cassette 218 is opened and closed, changes in both the arrival time (Ta + Tb) / 2 and the arrival time difference T (ab) are captured. Thus, the feature of this embodiment is that the necessity of readjustment of the lateral end regulating plates 231 and 232 and the rear end regulating plate 219 is determined.

(Explanation of control by CPU)
Next, the conveyance operation by the CPU 100 of this embodiment will be described with reference to the flowchart of FIG. 5 and 9 are denoted by the same reference numerals and description thereof is omitted. The difference between the flowcharts of FIGS. 5 and 9 is that the functions of S307, S308, S309, S310, and S311 are different. The CPU 100 executes the following control by a program stored in a ROM (not shown) in the CPU.

  Whether the recording material P reaches the sensor 213 (213a, 213b) and is the first to m-th (1 ≦ p ≦ m) transport operation after opening / closing the cassette 218, or the transport operation exceeding the mth operation after opening / closing the cassette 218 Is determined (S105). In the case of the transfer operation exceeding the mth time after opening / closing the cassette 218, the arrival time Tr (k) of the storage unit of the CPU 100 is updated so that the latest arrival time Tr (k) for n times is stored. Further, the arrival time difference T (ab) (k) between Ta and the arrival time Tb is calculated, and the arrival time difference T (a) of the memory 101 is stored so that the arrival time difference T (ab) (k) is stored. -B) Update (k) and store (S308). Thereafter, the average values Tr (k) (ave), T (ab) (ave), average values of the latest arrival times Tr (k) and arrival time differences T (ab) (k), respectively. Threshold values Tf, Td, and Tg set based on the above are calculated. Then, Tr (k) (ave), T (ab) (ave), Tf, Td, and Tg are stored in the memory 101 (S309), and the operation ends.

  On the other hand, if the cassette 218 is in the first to m-th transport operation after opening / closing (S105), it is determined whether it is the m-th (p = m) transport operation after opening / closing of the cassette 218 (S106). If p = m is not satisfied (if p <m), the arrival time difference Tx (ab) (p) after opening / closing the cassette 218 is calculated, and the arrival time Ts (p) after opening / closing the cassette 218 is stored in the memory 101. And arrival time difference Tx (ab) (p) is stored (S310). If p = m, the arrival time Ts (p) (p = 1, 2,..., m−1) after opening / closing the cassette 218 stored in the CPU 100 and the newly detected mth arrival time Ts (m ) To calculate an average value Ts (ave). Further, the arrival time difference Tx (ab) (p) (p = 1, 2,..., M−1) after opening / closing the cassette 218 stored in the memory 101 and the newly detected mth arrival time difference Tx ( An average value Tx (ab) (ave) is calculated from ab) (m) (S311). Then, the operations of (S112), (S212), (S113), and (S213) are performed in the same manner as in the first and second embodiments. It is determined whether there is a possibility of deviation or a conveyance failure.

  Further, when the arrival time T and the threshold value are compared, the determination may be made including the threshold value or may be made including the threshold value. In other words, the inequality sign (<,>) and the inequality sign with an equal sign (≦, ≧) used in the judgment formula may be used depending on the situation.

  As described above, according to the present embodiment, immediately after opening / closing of a cassette that is highly likely to cause a conveyance failure, the arrival time Ts and threshold value after the cassette opening / closing and the arrival time difference Tx (ab) and threshold value are set. Compare. Thereby, the state of the recording material P in the cassette after opening and closing the cassette can be determined. Therefore, even in a situation where the position of the recording material P in the cassette 218 is shifted obliquely with respect to the transport direction, it is possible to avoid the occurrence of a transport failure in advance.

  In the first to third embodiments, the arrival time immediately after opening and closing of the cassette is used. However, the present invention is not limited to this. For example, the same effect can be obtained by using the arrival times before and after the power of the image forming apparatus is turned on and off. Can be obtained. When the image forming apparatus is powered off, the CPU 100 cannot recognize the opening / closing of the cassette. Accordingly, it is effective to use the arrival times before and after the power is turned on and off when the loading state of the recording material P in the cassette changes when the power of the image forming apparatus is turned off.

  In this embodiment, the configuration of the image forming apparatus has been described. However, the present invention can also be applied to an option supply apparatus including a plurality of cassettes on which recording materials are stacked. The option supply device is a device that can be mounted as an optional device of the image forming apparatus described in the above embodiment.

(Other examples)
An image forming system can be configured by combining the image forming apparatus described in the first to third embodiments and a computer connected to the image forming apparatus. For example, by using a computer connected to the image forming apparatus as an input unit and a display unit, it is possible to display and notify a message prompting the user to confirm the regulating member. FIG. 10 shows an example of the image forming system.

  FIG. 10 shows a system configuration in which a computer 300 is connected to a server 302 via a network line 303, and an image forming apparatus 301 is connected to the computer 200. As an example, the arrival time is measured for the image forming apparatuses described in the first to third embodiments, and the measurement result is transmitted to the computer 300. The computer 300 further transmits arrival time information to the server 303. The server 303 can accumulate and manage arrival time information for each image forming apparatus. For example, for an image forming apparatus that frequently outputs information for prompting confirmation of the restriction member, information such as confirming whether the restriction member itself is normal may be transmitted to the computer 300. Thereby, it is possible to monitor the abnormality of the regulating member of the image forming apparatus.

  Note that such an image forming system may be configured to collect and manage information from other computers and printers connected to the server 303. In that case, a system can be configured by a combination of a plurality of computers and one printer, a plurality of computers and a plurality of printers, or a computer and a plurality of printers.

100 CPU
200 Image forming apparatus 213, 213a, 213b Sensor 216 Supply roller 218 Cassette 219 Rear end regulating plate 231 232 Horizontal end regulating plate P Recording material

Claims (11)

Loading means for loading recording materials;
Regulation means for regulating the position of the recording material in the stacking means;
A feeding means for feeding the recording material loaded on the loading means;
Detection means for detecting opening and closing of the loading means;
After the opening and closing of the stacking means is detected by the detection means, the arrival time from when the recording material is supplied by the supply means until the recording material reaches a predetermined position in the transport path is measured, A control means for comparing a threshold value based on an arrival time measured before the opening and closing of the stacking means is detected by the detecting means, and for outputting information indicating the state of the restricting means according to a comparison result;
An image forming apparatus comprising:   The image forming apparatus according to claim 1, wherein the control unit determines whether or not the regulating unit is deviated from a normal position according to the comparison result.   The sensor has a sensor that detects that the recording material has reached the predetermined position in the conveyance path, and the control unit measures the time from the start of the supply of the recording material until the recording material is detected as the arrival time. The image forming apparatus according to claim 1, wherein the image forming apparatus is an image forming apparatus.   If the arrival time is greater than the first threshold and less than the second threshold greater than the first threshold, the control means determines that the restriction means is not in a position relative to the size of the recording material. The image forming apparatus according to claim 1, wherein the image forming apparatus is an image forming apparatus.   If the arrival time is less than or equal to the first threshold, it is determined that the recording material has been normally conveyed; if the arrival time is greater than or equal to the second threshold, it is determined that a conveyance failure has occurred. The image forming apparatus according to any one of claims 1 to 4.   The image forming apparatus according to claim 1, wherein the restricting unit is a rear end restricting unit that restricts a rear end in a recording material conveyance direction. A first sensor and a second sensor for detecting the recording material in a direction orthogonal to the conveying direction of the recording material;
The restricting means is a lateral end restricting means for restricting an end portion of the recording material in a direction orthogonal to the recording material conveyance direction,
The control unit includes a first arrival time from the start of supplying the recording material to the detection of the recording material by the first sensor, and a recording material by the first sensor after starting the supply of the recording material. 2. The second arrival time until the detection is detected, and using the measured first and second arrival times, it is determined whether or not the lateral end regulating plate is displaced. The image forming apparatus according to claim 5.   The control means obtains a difference between the second arrival time and the second arrival time, compares the obtained difference with a threshold set based on the difference, and controls the lateral end restriction based on a comparison result. 8. The image forming apparatus according to claim 7, wherein it is determined whether or not the plate is displaced.   The control means determines that the recording material has been normally conveyed when the difference is equal to or less than the threshold value, and determines that a conveyance failure has occurred when the difference is equal to or greater than the threshold value. The image forming apparatus according to 8.   The image forming apparatus according to claim 1, wherein the arrival time is an average of a plurality of arrival times measured by conveying a plurality of recording materials. Display means for displaying the information;
The image forming apparatus according to claim 1, wherein the information includes information for prompting confirmation of a position of the restricting unit.

Images