JP2019018949A - Image forming device - Google Patents

Abstract

To provide an image forming device having a recording material determination part capable of detecting a mass (basis weight) per unit area from a light transmission amount or a light transmittance in order to determine image forming conditions, whereby a remaining amount of a recording material stored in a paper feeding part can be precisely calculated without adding new detection means.SOLUTION: The image forming device includes a storage part for storing a recording material, moving means for moving a recording material bundle stored in the storage part to a paper feedable position, opening/closing detection means for the storage part, and a recording material detecting part for detecting a surface density of the recording material fed from the storage part, and the number of remaining recording material stored in the storage part is determined from a mass of a paper bundle calculated from a workload required for moving the recording material bundle to the paper feedable position and a mass of one paper detected in the recording material detecting part.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an image forming apparatus.

  2. Description of the Related Art Conventionally, there is known an image forming apparatus that detects the type of recording material to be formed and detects the remaining number of recording materials in a paper feed cassette (Patent Document 1). That is, the remaining amount detecting device is configured by sheet type detecting means for detecting the sheet type in the sheet feeding cassette and remaining amount deriving means for deriving the remaining number of sheets in the sheet feeding cassette from the detection result.

  The paper type detecting means includes a transmittance data storing means for storing light transmittance data per sheet for each paper type, a transmittance detecting means for detecting the light transmittance of the first sheet bundle, and transmittance data. Each data in the storage means is constituted by an identification means for identifying the type of paper depending on whether or not there is a data that substantially matches the detected light transmittance.

  The remaining amount derivation means includes weight detection means for detecting the total weight of the paper in the paper cassette, storage means for storing the weight data for each detected type of paper, weight data per paper and paper And calculating means for calculating the remaining number from the total weight. After calculating the remaining number, the number of sheets used for printing is subtracted from the calculated value.

JP 2000-211771 A

  In the conventionally proposed technology for detecting the remaining number of recording material bundles in a paper feeding cassette, the type of recording material and the remaining amount are detected using the light transmittance to the recording material and the known transmittance data. Yes.

  However, when this recording material discriminating method is performed, recording materials having different recording material masses but having similar physical properties may be recognized as the same recording material. In that case, a deviation occurs in the decrease in the paper weight. Similarly, in the case of recording materials having the same recording material mass but different physical properties, the accuracy of remaining amount detection cannot be guaranteed.

  Further, when only the recording material detection result of the first recording material bundle is used, even when different types of recording materials are mixedly loaded in the cassette, a difference in the remaining amount display occurs. Further, the minute weight variation due to the difference in lots of the recording material bundle and the minute weight that changes depending on the moisture absorption state of the recording material are not taken into consideration. .

  An object of the present invention is to provide a new detection means, etc., in an image forming apparatus having a recording material discriminating section capable of detecting mass (basis weight) per unit area from light transmission amount or transmittance in order to obtain image forming conditions. It is an object of the present invention to provide an image forming apparatus that can accurately calculate the remaining amount of recording material accommodated in a sheet feeding unit without adding a color.

In order to achieve the above object, an image forming apparatus according to the present invention includes:
A storage unit that stores the recording material, a moving unit that moves the recording material bundle stored in the storage unit to a feedable position, an opening / closing detection unit of the storage unit, and a recording material that is fed from the storage unit A recording material detection unit that detects the surface density of the recording material, and the recording material detection unit detects the mass of the sheet bundle calculated from the amount of work necessary to move the recording material bundle to a feedable position. The remaining number of recording materials in the storage unit is obtained from the mass of each sheet.

  According to the present invention, in order to obtain the image forming conditions, in the image forming apparatus having the recording material discriminating unit capable of detecting the mass (basis weight) per unit area from the light transmission amount or the transmittance, a new detecting unit or the like Therefore, it is possible to provide an image forming apparatus that can accurately calculate the remaining amount of the recording material stored in the sheet feeding unit without adding the.

The flowchart regarding the remaining amount calculation according to the embodiment of the present invention. 1 is a schematic configuration diagram of an image forming apparatus according to an embodiment of the present invention. Schematic configuration diagram of recording material discriminator The block diagram of the control system which concerns on embodiment of this invention Flow chart for calculating remaining amount in conventional example Correlation diagram between sheet bundle weight and torque in an embodiment of the present invention Correlation diagram of basis weight and transmission coefficient in an embodiment of the present invention

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be exemplarily described in detail with reference to the drawings. Note that this embodiment is an embodiment to which the present invention can be applied, and is not limited to this.

(First embodiment)
<Image forming apparatus>
The image forming apparatus 100 shown in FIG. 2 is a four-color full-color electrophotographic full-color machine, and includes a recording material transport unit 1, four stations for each color of YMCK arranged in a substantially straight line in the horizontal direction, and fixing. A fixing device 2 is provided as a means. The image forming apparatus 100 includes a paper cassette 3, a paper feed roller 4, a paper presence / absence sensor 5 that detects the presence / absence of paper in the paper cassette, a recording material detection unit 6, and a temperature / humidity detection unit 7.

  The image forming apparatus 100 shown in the present embodiment forms an image signal for image formation from the control unit 8 and image data transmitted from a host computer or an image scanner (not shown) connected to the image forming apparatus 100. And a video controller 9. The control unit 8 and the video controller 9 correspond to setting means.

  The control unit 8 includes a memory such as a ROM or a RAM and a CPU. The memory stores an image formation control sequence for forming an image on a recording material, a fixing temperature control sequence of the fixing device 2, and the like. The CPU is connected to an image forming unit (charging, exposure, development, transfer, fixing, cleaning), and image forming conditions based on detection values obtained by the recording material detection unit 6 and the temperature / humidity detection unit 7. When an abnormality / warning of the image forming unit is detected, the abnormality / warning is displayed on a display unit (not shown) of the image forming apparatus 100.

  Each station includes a drum-type electrophotographic photosensitive member (hereinafter referred to as “photosensitive drum”) as an image carrier. The photosensitive drum 10 is supported by the image forming apparatus 100 so as to be rotatable in the arrow R1 direction. Around the photosensitive drum 10, a primary charger (charging means) 11, an exposure device (exposure means) 12, a developing device (developing means) 13, a cleaning device (cleaning means) 14, and a front are sequentially arranged along the rotation direction. An exposure device (pre-exposure means) 15 is arranged.

  The developing device (developing unit) 13 is provided with a developing roller 16 for supplying a developer to the photosensitive drum 10. Further, an intermediate transfer belt 20 (hereinafter referred to as “ITB”) that rotates in the direction of arrow R2 is disposed so as to be sandwiched between the photosensitive drum 10 and the first transfer roller 18 (transfer means) at each station. . The second transfer roller 19 is disposed so as to contact the ITB 20.

  A fixing device 2 including a fixing roller 21 and a pressure belt 22 is disposed at the end of a paper passing portion conveyed by the ITB 20.

  Next, an outline of the process up to printing will be described.

  The image forming apparatus 100 includes a paper feed motor that feeds and transports a recording material, and the fed recording material is transported from the ITB 20 to the fixing unit 2. The recording material detection unit 6 is arranged at a position upstream of the second transfer unit 19, and the fed recording paper is conveyed by the conveying means 1, and the control unit 8 is in that state the type of the recording material A detection operation for discriminating between the two is performed.

  During image formation, the photosensitive drum 10 is rotationally driven at a predetermined process speed in the direction of the arrow R1. The surface of the photosensitive drum 10 is substantially uniformly charged by performing bias application control from a bias power source (not shown) by the primary charger 11. The control unit 8 controls the exposure device 12 so that an image pattern based on the image signal is irradiated with light from a laser chip provided in the exposure device 12 with an exposure amount instructed from the video controller 9. The surface of the photosensitive drum 10 after charging is irradiated with scanning light.

  The charge held on the surface of the photosensitive drum 10 is removed by charging to form an electrostatic latent image. To this electrostatic latent image, a bias is applied to a developing roller 16 which is a developer carrying member provided in the developing device 13, whereby the toner flies and adheres to the photosensitive drum and is developed as a toner image. At this time, the larger the potential difference that is the difference between the exposure amount and the bias applied to the developing roller, the larger the toner amount to be developed.

  The developed toner image is primarily transferred from the photosensitive drum 10 to the ITB 20 in the first transfer unit 18, and is secondarily transferred from the ITB 20 to the recording material in the second transfer unit 19. The recording material is conveyed to the fixing device 2 where it is heated and pressurized to fix the toner image on the recording material and discharged onto the paper discharge tray 23. The four-color full-color image formation on one side (front surface) of one recording material is thus completed.

<Detection of recording material type>
FIG. 3 is a schematic cross-sectional view of the recording material detection unit 6 that detects information on the recording material. The information required for printing the recording material is the surface smoothness of the recording material and the mass per unit area (also referred to as basis weight).

  The surface smoothness of the recording material is obtained from the reflected light rate (or a value representing reflectance, specifically a value representing the amount of reflected light) and a relational expression, and the mass per unit area or basis weight (surface density) is It is obtained from the transmission coefficient (or transmittance, specifically, a value representing the amount of transmitted light) and a relational expression between them. Since the transmission coefficient is a value determined from the transmittance, the value decreases as the mass or basis weight per unit area increases, and the value increases as the mass or basis weight per unit area decreases.

  Here, when the amount of light emitted from the light source is determined in advance, the reflectance is detected from the value representing the reflected light amount, and the transmission coefficient is detected from the value representing the transmitted light amount (hereinafter referred to as “paper type”). It is possible to calculate with the accuracy required for this.

  As shown in FIG. 3, the recording material detection unit 6 includes an imaging lens 1113, a CMOS area sensor 1110, a reflected light LED 1111, and a transmitted light LED 1112. The imaging lens 1113 forms an image of the imaging region on the recording material, and the CMOS area sensor 1110 is disposed on this imaging surface. The reflected light LED 1111 is a first light irradiating unit that irradiates the imaging region from obliquely above, and the transmitted light LED 1112 is a second light irradiating unit for detecting a transmitted light amount of the recording material.

  Light using the reflected light LED 1111 as a light source is applied to the recording material surface so as to have a predetermined incident angle. The reflected light from the recording material is condensed through the imaging lens 1113 and imaged on the CMOS area sensor 1110. The controller reads the surface image of the recording material by controlling the CMOS area sensor and taking out an electrical signal proportional to the amount of received light. Therefore, the reflected image from the surface of the recording material represents the uneven state of the paper surface of the imaging region. The control unit detects the reflected light rate using the reflected image.

  Next, a method for detecting the transmission coefficient of the recording material will be described. Light using the transmitted light LED 1112 as the second light irradiating means as a light source is irradiated in the direction of the image reading sensor 123 from the opposite side of the image reading sensor 123 to the recording material. The transmitted light of the recording material is condensed through the imaging lens 1113 and irradiated to the CMOS area sensor 1110. At this time, the transmission coefficient is detected from the luminance value in the entire sensor area or in a predetermined range.

  The configuration of the recording material detection unit 6 is not limited to this embodiment, and the present embodiment is an embodiment to which the present invention can be applied.

<Detection of remaining recording material>
The remaining amount of recording material is detected based on the mass of the recording material bundle in the paper feed cassette and the mass of one recording material.

  First, a method for measuring the mass of the recording material bundle will be described.

  The recording material bundle housed in the paper feed cassette is lifted up to a paper feedable position by the moving means. FIG. 6 is a graph in which the horizontal axis represents the mass of the recording material bundle, and the vertical axis represents the torque required to lift up the recording material bundle. From this result, the mass of the recording material bundle can be calculated by measuring the torque required at the time of lift-up. Further, the method for calculating the mass is not limited to the torque measurement, and an electric power value or a current value necessary for lift-up can also be used.

Next, calculation of the mass of one recording material will be described. FIG. 7 is a graph in which the horizontal axis represents the basis weight (mass per unit area) and the vertical axis represents the transmission coefficient. There is a correlation between the basis weight and the transmission coefficient. When the basis weight is X and the transmission coefficient is Y, in the system in which the measurement of FIG.
Y = 627912X- ^0.98
Can be obtained.

  Therefore, the actual basis weight of the actually measured paper can be calculated using the transmission coefficient measured from the recording material detection unit. Then, the mass of one recording material is obtained by multiplying the basis weight obtained as described above by the size of the recording material.

  The remaining number of recording material bundles can be calculated by dividing the mass of the recording material bundle obtained as described above by the mass of one recording material. Further, the remaining amount displayed on the image forming apparatus may have a width such that the minimum unit for displaying the remaining amount is set to every 10 sheets, in addition to using the value calculated as described above.

  FIG. 1 is a flowchart of the operation relating to the remaining recording material detection according to the present embodiment. FIG. 4 shows a control system of this embodiment.

  The control for detecting the remaining amount of recording material will be described with reference to FIG.

  In S1, the image forming apparatus 100 detects whether the paper feed cassette is opened or closed. For the open / close detection, an open / close detection sensor (not shown) of the paper feed cassette is used. When the cassette is opened and closed in S1, the control unit treats the recording material in the paper feeding cassette as a new recording material, and stores the “recording material remaining amount” and “recording material bundle mass” from the memory immediately before. Erase (S2).

  In S3, a lift-up operation is performed to move the recording material bundle in the paper feed cassette to a paper feedable position. At this time, the mass of the recording material bundle is detected, and the control unit saves the recording material bundle mass in the memory, and the calculation unit stores the remaining recording material from the detected recording material bundle mass and the paper setting of the paper feed cassette. Calculate the amount. The calculated recording material remaining amount is displayed on the display unit of the image forming apparatus and stored in the memory (S4). Examples of the paper setting of the paper feed cassette used in the calculation of this step include a paper size and a paper type. From the maximum basis weight value and the paper size in the paper type category, the mass of one sheet is obtained, and the number of recording material bundles is calculated.

  Further, the basis weight value used in the calculation for obtaining the initial number of recording material bundles is not limited to the above, and other values may be used. The minimum number of sheets that can be guaranteed from the maximum basis weight that can be passed by the image forming apparatus can be estimated, or the remaining amount can be calculated using the basis weight immediately before detection of opening / closing of the paper cassette. There is also a method of displaying the remaining amount as “Calculating” until the basis weight is detected after the actual paper feeding.

  After calculating the initial number of recording material bundles, the main body shifts to a printable state and waits for a print instruction (S5).

  If the cassette has not been opened / closed in S1, the control unit determines that the recording material in the paper feed cassette has not been changed, and the “recording material remaining amount” and “recording material bundle mass” up to immediately before are determined. Is held in the memory (S11). Thereafter, the main body shifts to a printable state and waits for a print instruction (S5).

  When the main body receives a print instruction, the recording material detection unit 6 determines the paper type of the recording material for the fed recording material (S6, S7).

  The calculation unit calculates the basis weight of the recording material using the transmission coefficient obtained from the recording material detection unit. Further, the calculated basis weight is stored in the memory (S8).

  In S9, the calculation unit calculates the mass of one recording material using the basis weight and the paper size obtained in S8, and the recording material mass of one sheet is calculated from the recording material bundle mass stored in the memory. Is divided by the mass of one recording material to determine the remaining amount in the paper feed cassette. Also, the display on the display unit is changed. Further, the control unit changes the value of “recording material bundle mass” stored in the memory to the value of “recording material bundle remaining mass”.

  In S10, the control unit confirms the detection result of the paper presence / absence sensor in the paper cassette and confirms whether the paper cassette is out of paper. When the paper presence / absence detection sensor detects the absence of paper, the control unit displays “no paper” (S11). If the presence of paper is detected in S10, the presence / absence of the next print instruction is confirmed (S13). If there is no print instruction in S13, the process shifts to a printable state in S5, and the subsequent flow is repeated. If there is a print instruction in S13, the process proceeds to recording material detection in S7, and the subsequent flow is repeated.

  Depending on the accuracy of the recording material detector, the mass detection of one recording material varies depending on the accuracy of the recording material detection in the repetition of the flow of S5 or S7 to S13. There is a possibility that it will fluctuate from one paper pass to another. In order to avoid such a situation, the basis weight value used in the calculation of the remaining amount may be changed to use the average value of the latest five sheets.

  For the recording material bundle in the paper feed cassette, the mass of the recording material bundle is measured, and the mass of the paper used for printing is also calculated. As for the mass of the recording material bundle, the remaining mass in the cassette is updated by subtracting the mass of the used recording material. By dividing the remaining mass in the cassette by the mass of the printed recording material, the number of recording materials remaining in the cassette can be calculated.

  In this embodiment, since the basis weight is detected and the remaining amount is calculated for all the recording materials, the remaining amount can be obtained even when different types of recording materials are mixedly loaded in the paper feed cassette. It becomes possible to adjust the display appropriately.

  Furthermore, if the lift-up operation of S3 is performed at an arbitrary timing, the actual remaining mass of the sheet bundle can be measured again, so that the accuracy of calculating the remaining amount can be improved. For example, by adding a flow such as performing a lift-up operation at the timing of waiting for a print instruction when the remaining amount of paper is 100 sheets or less, the difference between the calculated remaining amount and the actual remaining amount can be corrected.

  In this embodiment, the mass (basis weight) per unit area is detected from the light transmission amount or transmittance for all the recording materials, and the mass of each recording material is calculated from the basis weight and the recording material size. Ask. Further, the mass of the recording material bundle in the paper feed cassette is measured in advance. As for the mass of the recording material bundle, the remaining mass in the cassette is updated by subtracting the mass of the used recording material. It is possible to provide an image forming apparatus that can accurately calculate the number of recording materials remaining in the cassette by dividing the remaining mass of the recording material in the cassette by the mass of the recorded recording material.

  The present invention grasped from the above-described embodiment is as follows.

  “Accommodating portion for accommodating recording material, moving means for moving recording material bundle accommodated in the accommodating portion to a feedable position, open / close detecting means for the accommodating portion, and recording fed from the accommodating portion A recording material detection unit that detects the surface density of the material, and the recording material detection unit detects the mass of the sheet bundle calculated from the amount of work required to move the recording material bundle to a feedable position. In other words, the image forming apparatus is characterized in that the remaining number of recording materials in the storage unit is obtained from the mass of each sheet.

  Further, “in the step of calculating the remaining number of recording materials, the surface density of a plurality of recording materials accommodated in the accommodating portion is detected, and the remaining number of recording materials in the accommodating portion is determined from the plurality of detection results Is an image forming apparatus characterized by

  Furthermore, “the recording material detection unit includes a light or ultrasonic wave irradiation unit and a transmitted light or ultrasonic wave detection unit”.

100 image forming apparatus,
1 conveying means, 3 paper cassette, 5 paper presence sensor in cassette,
6 Recording material detection unit, 7 Temperature / humidity detection unit, 8 Control unit, 9 Video controller

Claims (3)

A storage unit that stores the recording material, a moving unit that moves the recording material bundle stored in the storage unit to a feedable position, an opening / closing detection unit of the storage unit, and a recording material that is fed from the storage unit A recording material detection unit for detecting the surface density of
Based on the mass of the sheet bundle calculated from the amount of work required to move the recording material bundle to the feedable position and the mass of each sheet detected by the recording material detection unit, the remaining recording material in the storage unit is obtained. An image forming apparatus characterized in that the number of sheets is obtained.   In the step of calculating the remaining number of recording materials, the surface density of a plurality of recording materials accommodated in the accommodating portion is detected, and the remaining number of recording materials in the accommodating portion is calculated from a plurality of detection results. The image forming apparatus according to claim 1.   The image forming apparatus according to claim 1, wherein the recording material detection unit includes a light or ultrasonic wave irradiation unit and a transmitted light or ultrasonic wave detection unit. .