JP2006071788A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus for successively detecting a highly accurate toner residual amount, by using an optical transmission residual amount detector. <P>SOLUTION: A developer residual amount detector has a developer residual amount detecting mode in the developer residual amount detector, corresponding to a plurality of agitation drive speeds for an agitation means 28. The image forming apparatus A changes the agitation drive speed of the agitating means 28 to a prescribed speed, in response to prescribed timing; stores a developer residual amount in a developer residual amount detecting mode, corresponding thereto to a storing means 26; corrects the developer residual amount in the developer residual amount detecting mode, corresponding to the agitating drive speed of the agitating means 28 in forming images, on the basis of a value of the storing means 26 during forming the images; and stores it to the storing means 26 to make the value stored to the storing means 26 the developer residual amount. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an image forming apparatus that forms a latent image on an image carrier by, for example, electrophotography or electrostatic recording, and develops the latent image to obtain a visible image.

  For example, an image forming apparatus such as a printer using an electrophotographic method uniformly charges a photosensitive drum, which is an image carrier, and forms a latent image by selective exposure to the photosensitive drum. Is visualized with a fine powder toner as a developer to form a visible image (that is, a toner image), the toner image is transferred to a recording medium, and further, heat and pressure are applied to the transferred toner image. Image recording is performed by fixing the image on a recording medium.

  Such an image forming apparatus is provided with a toner remaining amount detecting device for measuring the remaining amount of toner stored in the toner container. There are various types of toner remaining amount detection devices. As an example of a cheaper and simpler configuration, there is a light transmission type toner remaining amount detection as disclosed in Patent Document 1, for example. The light transmission type toner remaining amount detection is a method in which detection light is allowed to pass through a toner container and the remaining amount of toner stored in the toner container is detected based on the passing time of the detection light.

  The configuration of the light transmission type toner remaining amount detection device described in Patent Document 1 will be described. Detection light emitted from a light emitting member such as a light emitting element passes through a first guide portion made of a light transmitting member and enters a toner container. The light enters the toner container from the light transmitting first window member. In addition, the detection light that has entered the toner container passes through the second transparent window member provided in the toner container and has a light transmission property to the outside of the toner container. It reaches a light receiving member such as a light receiving element via a second guide portion made of a transmissive member, and detects the remaining amount of developer in the toner container based on the length of time that the light receiving member receives the detection light. .

  Note that the sheet member of the toner conveying portion in the toner container has intruded about 0.5 to 4 mm with respect to the first window member and the second window member in a part of the longitudinal region. It also serves to wipe off toner adhering to the surfaces of the member and the second window member. With such a configuration, even if the toner is covered on the window member, the window member is cleaned by the sheet member, and the detection light can pass through the toner container. When a large amount of toner is in the toner container, even if the sheet member cleans the surface of the window member, the toner is immediately covered and shields the window member, so that the detection light passes through the toner container. The time to do is short.

  However, when the toner in the toner container is consumed and the remaining amount becomes low, the interval between the sheet member cleaning the window member and the toner covering again increases. Takes longer to pass through the toner container. In this way, the light transmission type toner remaining amount detecting device measures the remaining amount of toner in the toner container based on a change in the length of time that the detection light passes through the toner container.

  That is, when the toner container is in a large amount of toner, the detection light passage time is short. Conversely, when the toner is consumed, the detection light passage time is long. If the passage time of the detection light when the toner in the toner container runs out is set in advance as a threshold value, the process time when the passage time of the detection light passing through the toner container exceeds the threshold value is set. The user can be notified that the toner in the cartridge has run out.

Further, if a toner remaining amount detection sequence is created in which the passage time of the detection light passing through the toner container and the toner remaining amount in the toner container are made to correspond, the toner container corresponding to the passage time of the detection light in the toner container The remaining amount of toner can be sequentially detected by notifying the user of the remaining amount of toner in real time.
JP 2003-241500 A

  However, in the above-described toner remaining amount detection method in the image forming apparatus, there is a constant amount from a state where a large amount of toner is contained in the toner container to a state where the toner in the toner container is consumed and the remaining amount decreases. It is very difficult to detect the remaining amount of toner with high accuracy at the stirring drive speed.

  For example, when the remaining amount of toner is large, the detection light passing time is longer when the stirring drive speed is low, and when the remaining toner amount is low, the detection light passing time is longer when the stirring drive speed is high. This is because when the stirring drive speed is high, the toner in the toner container is always in the cloud state, and when the stirring drive speed is low, the toner stays at the bottom of the toner container after entering the cloud state.

  That is, when the remaining amount of toner is large and the stirring drive speed is high, the toner is always in a cloud state and the density is high, so that the detection light does not easily pass. When the remaining amount of toner is large and the stirring drive speed is slow, the toner is After reaching the low density cloud state, it stays at the bottom of the toner container, so that the detection light easily passes (passes during the low density cloud state).

  When the remaining amount of toner is low and the agitation drive speed is fast, the toner is always in the cloud state and the density is small, so the detection light easily passes. When the remaining toner amount is low and the agitation drive speed is slow, the toner is in the cloud state Since the toner stays at the bottom of the toner container (the toner covers the detection window), the detection light is difficult to pass.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an image forming apparatus capable of sequentially detecting the remaining amount of toner with high accuracy using a light transmission type remaining amount detecting device.

The above object is achieved by the image forming apparatus according to the present invention. In summary, the present invention provides an image carrier, a developer carrier that carries and transports a developer to develop a latent image formed on the image carrier into a toner image, and the developer. A developer storage unit that is housed, a stirring unit that can be driven to stir the developer in the developer storage unit, and a sensor that detects the remaining amount of the developer in the developer storage unit An image forming apparatus comprising: a developer remaining amount detecting device having a means; a storage means for updating and storing the developer remaining amount; and a transfer means for transferring the toner image to a recording medium.
The developer remaining amount detecting device has a developer remaining amount detecting mode by the developer remaining amount detecting device corresponding to a plurality of stirring drive speeds of the stirring means,
The image forming apparatus changes the stirring drive speed of the stirring unit to a predetermined speed in accordance with a predetermined timing, stores the developer remaining amount in the developer remaining amount detection mode corresponding thereto in the storage unit, and At the time of formation, the developer remaining amount in the developer remaining amount detection mode corresponding to the stirring drive speed of the stirring unit during image formation is corrected based on the value of the storage unit, and stored in the storage unit. The image forming apparatus is characterized in that a value stored in a storage unit is used as a developer remaining amount.

  The image forming apparatus of the present invention can perform sequential detection of the remaining amount of toner with high accuracy by the light transmission type remaining amount detecting device.

  The image forming apparatus according to the present invention will be described below in more detail with reference to the drawings. The examples described below illustrate the present invention by way of example, and the dimensions, materials, shapes, relative arrangements, etc. of the components described below are not particularly specified unless otherwise specified. However, the scope of the present invention is not limited thereto.

Example 1
FIG. 1 shows a schematic cross section of an embodiment of an image forming apparatus according to the present invention. The image forming apparatus A according to the present embodiment is a laser beam printer that forms an image on a recording medium 6 such as a recording sheet or an OHP sheet by electrophotography in accordance with image information. In the image forming apparatus A of this embodiment, as will be described in detail later, the process cartridge B can be attached to and detached from the image forming apparatus main body 100.

  The image forming apparatus A is used by being connected to a host 14 such as a personal computer. In the controller unit 33, a print request signal and image data from the host 14 are processed, and the scanner 3 as an exposure unit is controlled to form an electrostatic latent image on the image carrier 1. In this embodiment, the image carrier 1 is a drum-shaped electrophotographic photosensitive member (hereinafter referred to as “photosensitive drum”), and is rotated in the direction of arrow Ra in the drawing.

  In this embodiment, the photosensitive drum 1 is charged by a roller-shaped charging member that is in pressure contact with the photosensitive drum 1, that is, a DC contact charging roller (hereinafter referred to as a “charging roller”) 2, which is a charging unit. Uniformly charged. A DC voltage fixed to a predetermined value as a charging bias is applied to the charging roller 2 to uniformly charge the surface of the photosensitive drum 1 negatively. The charging roller 2 is driven to rotate in the direction of the arrow Rd in the figure as the photosensitive drum 1 rotates. The charging roller 2 is in contact with the entire length of the photosensitive drum 1 (in the direction orthogonal to the conveyance direction of the recording medium 6).

  The uniformly charged photosensitive drum 1 is exposed by a laser beam E from a scanner 3 as an exposure unit, and an electrostatic latent image is formed on the surface thereof. The scanner 3 includes a laser light source, a polygon mirror, a lens system, and the like, and scans and exposes the photosensitive drum 1 under the control of the controller unit 33.

  Thereafter, the electrostatic latent image is visualized as a toner image by being supplied with a developer by the developing device 4 as a developing means. That is, in this embodiment, the developing device 4 includes a developer container that stores a negatively chargeable nonmagnetic toner (hereinafter simply referred to as “toner”) T that is a one-component developer, that is, a toner container 21. Have. In this embodiment, as the toner T, a substantially spherical toner having excellent fixing characteristics and low viscoelasticity and having a volume average particle diameter of about 6 μm, which enables high-speed image formation (printing), was used.

  A part of the toner container 21 facing the photosensitive drum 1 is opened over substantially the entire longitudinal direction of the photosensitive drum 1, and the developing is a roller-shaped developer carrying member that constitutes developing means in this opening. A roller 23 is disposed. The developing roller 23 is pressed and brought into contact with the photosensitive drum 1 located at the upper left in the drawing of the developing device 4 so as to have a predetermined penetration amount, and is driven to rotate in the direction of the arrow Rb in the drawing.

  An elastic roller 24 is in contact with the developing roller 23 as a means for supplying a developer to the developing roller 23 and stripping off the undeveloped toner from the developing roller 23. The elastic roller 24 is rotatably supported by the toner container 21. The elastic roller 24 is a rubber sponge roller from the viewpoint of supplying toner to the developing roller 23 and stripping off undeveloped toner, and is driven to rotate in the direction of arrow Rc in the figure, which is the same direction as the developing roller 23.

  Further, the developing device 4 includes a developing blade 25 as a developer layer thickness regulating member that regulates the amount of toner carried on the developing roller 23. The developing blade 25 is made of an elastic phosphor bronze metal thin plate, and is provided so that the vicinity of the free end side is in contact with the outer peripheral surface of the developing roller 23 in surface contact. The toner carried on the developing roller 23 by rubbing against the elastic roller 24 is given a charge by frictional charging when passing through the contact portion with the developing blade 25 and is regulated to a thin layer.

  In the developing device 4 having such a configuration, a DC voltage fixed to a predetermined value as a developing bias is applied to the developing roller 23. Thus, in this embodiment, the exposed portion on the surface of the uniformly charged photoreceptor drum 1 where the negative charge is attenuated is developed by reversal development.

  On the other hand, the recording medium 6 is separated and fed from the recording medium container 16 by a supply roller 16a and the like, and is temporarily stopped by a registration roller 16b. The registration roller 16b synchronizes the recording position of the recording medium 6 with the formation timing of the toner image on the photosensitive drum 1, and moves to a facing portion (transfer portion) between the transfer roller 5 serving as transfer means and the photosensitive drum 1. Then, the recording medium 6 is sent out.

  Thus, the visualized toner image on the photosensitive drum 1 is transferred to the recording medium 6 by the action of the transfer roller 5. The recording medium 6 to which the toner image is transferred is conveyed to the fixing device 9. Here, the unfixed toner image on the recording medium 6 is permanently fixed to the recording medium 6 by heat and pressure. Thereafter, the recording medium 6 is discharged out of the apparatus by a discharge roller 16c and the like.

  Further, untransferred toner remaining on the photosensitive drum 1 without being transferred is cleaned by a cleaning means (cleaner) 7. That is, the cleaner 7 scrapes off the transfer residual toner from the photosensitive drum 1 by the cleaning blade 7 a serving as a cleaning member and stores it in the waste toner container 8. The cleaned photosensitive drum 1 is used for image formation.

  In this embodiment, the image forming apparatus A integrally forms an image carrier having an electrophotographic photosensitive member as the photosensitive drum 1 and process means acting on the image carrier into a cartridge. Is a process cartridge type that can be attached to and detached from the apparatus main body 100.

  Here, the process means includes charging means for charging the electrophotographic photosensitive member, developing means for supplying a developer to the electrophotographic photosensitive member, and cleaning means for cleaning the electrophotographic photosensitive member. That is, the process cartridge is a charging unit, a developing unit, a cleaning unit, and an electrophotographic photosensitive member integrated into a cartridge, and the cartridge can be attached to and detached from the main body of the electrophotographic image forming apparatus, or the charging unit, At least one of the developing means and the cleaning means and the electrophotographic photosensitive member are integrally formed into a cartridge so as to be detachable from the main body of the electrophotographic image forming apparatus, or at least the developing means and the electrophotographic photosensitive member. The cartridge is integrated with the body so that the cartridge can be attached to and detached from the main body of the electrophotographic image forming apparatus.

  In this embodiment, the photosensitive drum 1, the charging roller 2, the developing device 4, and the cleaner 7 are integrally formed into a cartridge to form a process cartridge B, which is detachable from the apparatus main body 100. The process cartridge B is detachably mounted on the apparatus main body 100 via mounting means (not shown) provided in the apparatus main body 100.

  The process cartridge B is provided with a storage means 26. As the storage unit 26, for example, an arbitrary form such as a contact nonvolatile memory, a contactless nonvolatile memory, a volatile memory having a power source can be used. In this embodiment, a non-contact nonvolatile memory 26 is mounted on the process cartridge B as a storage means. The non-contact non-volatile memory 26 has an antenna (not shown) which is an information transmission unit on the memory side, and communicates wirelessly with a control unit (CPU) 32 provided in the image forming apparatus main body 13 so that information can be stored. Reading and writing are possible. That is, in this embodiment, the CPU 32 includes a control unit, a calculation unit, a storage unit (ROM), a clock, and the like, and further includes functions of an information transmission unit on the apparatus body side and a reading / writing unit of information in the memory 26. . As will be described in detail later, the storage means 26 stores the toner consumption amount and the number of images formed (printed) by the toner remaining amount detection.

  Details of toner conveyance and toner remaining amount detection to the process cartridge B and the elastic roller 24 provided in the process cartridge B in the present embodiment will be described.

  As shown in FIG. 2, in this embodiment, the process cartridge B is a separate body, and the cleaning unit 11 constituting the cleaner 7 and the developing device unit 12 constituting the developing device 4 are integrated. Has become a frame structure.

  In the developing device unit 12, the first stirring member 28 a and the second stirring member 28 b are placed in the toner container 21 by the toner container 21 in order from the side close to the opening 41 in the direction intersecting the longitudinal direction of the toner container 21. It is rotatably supported.

  Next, the configuration of the agitating member 28 (28a, 28b) will be described. The first agitating member 28a and the second agitating member 28b are obtained by attaching flexible sheet members 28a2, 28b2 to the rod members 28a1, 28b1. When the first stirring member 28a and the second stirring member 28b rotate in the toner container 21, the sheet members 28a2 and 28b2 of the first stirring member 28a and the second stirring member 28b become the bottom surface of the toner container 21. Scatter toner T accumulated in the toner. The toner T is sent out of the toner container 21 through the opening 41, and thereafter developed on the surface of the photosensitive drum 1 via the toner supply roller 24 and the developing roller 23. In the present embodiment, the first stirring member 28 a and the second stirring member 28 b are connected to the developing roller 23 by a gear (not shown), and the driving roller provided in the image forming apparatus main body 100 drives the developing roller 23 together. A configuration in which the one stirring member 28a and the second stirring member 28b are variably rotated is used.

  Next, the light transmission type developer remaining amount detecting method and apparatus will be described with reference to FIGS.

  As shown in FIG. 2, the toner container 21 of the process cartridge B that stores the toner T is provided with a light transmission window 26a and a light transmission window 26b. Further, as shown in FIG. 3, the image forming apparatus main body 100 is provided with sensor means including a light emitting element 30a and a light receiving element 30b that constitute the developer remaining amount detecting device 30.

  According to the developer remaining amount detection device 30 of the present embodiment, the detection light L emitted from the light emitting element 30a passes through the light guide 31a disposed over the length of the toner container 21 and passes through the light transmission window 26a. The light enters the toner container 21. Then, the detection light L incident on the inside of the toner container 21 passes through the light transmission window 26b to the outside of the toner container 21. The detection light L that has passed to the outside of the toner container 21 reaches the light receiving element 30b through the light guide 31b that is also disposed over the length of the toner container 21, and the light detection element 30b detects how much time the detection light L is. The remaining amount of the toner T stored in the toner container 21 is detected based on whether or not the light is received.

  The sheet member 28a2 of the first stirring member 28a penetrates about 0.5 to 4 mm with respect to the light transmission windows 26a and 26b in a part of the longitudinal region, and adheres to the surfaces of the light transmission windows 26a and 26b. It also serves to wipe off the toner. With this configuration, even if toner is covered on the light transmission windows 26a and 26b, the surface of the light transmission windows 26a and 26b is cleaned by the sheet member 28a2, and the detection light L passes through the toner container 21. It becomes possible to do. In a state where a large amount of toner T is contained in the toner container 21, even if the sheet member 28a2 cleans the surface of the light transmission windows 26a and 26b, the toner is immediately covered and the light transmission windows 26a and 26b are shielded from light. Therefore, the time for the detection light L to pass through the toner container 21 is short.

  However, when the toner T in the toner container 21 is consumed and the remaining amount is reduced, the interval until the toner T is again covered after the sheet member 28a2 cleans the light transmission windows 26a and 26b is increased. Therefore, the time for the detection light L to pass through the toner container 21 correspondingly increases. In this way, in the light transmission type developer remaining amount detecting device, the remaining amount of the toner T in the toner container 21 is measured by the change in the length of time that the detection light L passes through the toner container 21.

  That is, the passage time of the detection light L is short when the toner T is in a large amount in the toner container 21, and the passage time of the detection light L is long when the toner T is consumed. If the passage time of the detection light L when the toner T in the toner container 25 runs out is set in advance as the threshold value Y, the passage time of the detection light L passing through the toner container 21 is a threshold value. When Y is exceeded, the user can be informed that the toner T in the process cartridge B has run out.

  Further, if a toner remaining amount detection sequence in which the passage time of the detection light L passing through the toner container 21 is associated with the remaining amount of the toner T in the toner container 21 is created, the detection light L in the toner container 21 is detected. Corresponding to the passing time, it is possible to sequentially detect the remaining amount of toner to notify the user of the remaining amount of toner T in the toner container 21 in real time.

  Here, the relationship between the stirring speed and the toner remaining amount detection accuracy in this embodiment will be described.

  FIG. 4 is a graph showing the relationship between the toner consumption amount in the toner container 21 and the passage time during which the detection light L of the developer remaining amount detection device has passed through the toner container 21 with respect to the stirring speed 3 level. The speed increases in the order of speed 1 <speed 2 <speed 3. When the toner consumption on the horizontal axis is 0%, the toner container 21 is in an initial state in which a predetermined amount of toner T is packed, and when the toner consumption is 100%, the toner T in the toner container 21 is completely consumed. Indicates that the condition has disappeared.

  The passage time of the detection light L on the vertical axis indicates the passage time when the detection light L of the developer remaining amount detection device 30 passes through the toner container 21, and is detected in a state where the toner T in the toner container 21 is large. Although the transit time for the light L to pass through the toner container 21 is short (= short), the toner T in the toner container 21 is consumed, and as the toner T is reduced in the toner container 21, the detection light L is transferred to the toner container 21. The transit time passing through the interior is large (= long). Here, the state in which the detection light L does not pass through the toner container 21 is 0, and the state in which the detection light L continues to pass through the toner container 21 is 100.

  As shown in FIG. 4, in this embodiment, when the remaining amount of toner is large, the slower the stirring drive speed is, the longer the detection light passes, and when the remaining amount of toner is small, the faster the stirring drive speed is. However, the passage time of the detection light becomes longer. This is because when the stirring drive speed is high, the toner in the toner container 21 is always in the cloud state, and when the stirring drive speed is low, the toner stays at the bottom of the toner container after entering the cloud state.

  That is, when the remaining amount of toner is large and the stirring drive speed is high, the toner is always in a cloud state and the density is high, so that the detection light does not easily pass. When the remaining amount of toner is large and the stirring drive speed is slow, the toner is After the low density cloud state, the detection light easily passes because it stays at the bottom of the toner container (passes during the low density cloud state).

  When the remaining amount of toner is low and the agitation drive speed is fast, the toner is always in the cloud state and the density is small, so the detection light easily passes. When the remaining toner amount is low and the agitation drive speed is slow, the toner is in the cloud state Since the toner stays at the bottom of the toner container (the toner covers the detection window), the detection light is difficult to pass.

  However, in this embodiment, if the stirring speed is set to speed 2, the remaining amount of toner can be detected with high accuracy regardless of the remaining amount of toner, and the stirring speed for detecting high-accuracy toner remaining is set to speed 2 (hereinafter referred to as “high” Called “accuracy check mode”).

  In this embodiment, since it is desired to transport as much toner as possible to the elastic roller 24, it is necessary to increase the stirring speed, and the normal speed uses the speed 3 (hereinafter referred to as “normal residual detection mode”).

  Here, in the present embodiment, it is proposed that the high-accuracy residual detection mode is performed for every 100 printed sheets, the toner consumption amount in the normal residual detection mode is corrected, and the accuracy of the toner residual amount detection is improved.

  First, a method for correcting the remaining toner amount detection in the normal residual detection mode using the high accuracy residual detection mode will be described.

  Table 1 below shows the passage time of the detection light L of the developer remaining amount detection device passing through the toner container 21 with respect to the toner consumption in the normal residual detection mode and the high accuracy residual detection mode. Here, the state in which the detection light L does not pass through the toner container 21 is 0, and the state in which the detection light L continues to pass through the toner container 21 is 100.

  From Table 1, the change amount of the detected light passing amount in the normal residual detection mode and the high accuracy residual detection mode with respect to the toner consumption transition was calculated, and a correction coefficient for correcting the normal residual detection mode was derived. A method for calculating the correction coefficient will be described.

  In Table 1, when the normal amount of detected light passing when the toner consumption is 0 is expressed as normal (0), for example, the correction coefficient when the toner consumption transition is 0% -10% is {high accuracy (10)- High precision (0)} / {normal (10) −normal (0)}.

  The relationship between the toner consumption transition and the correction coefficient is shown in Table 2 below.

  How to use this correction coefficient will be described. The high-accuracy residual detection mode is performed at a certain timing, stored in the storage means 26, and the value is set as the toner consumption. When the normal remaining detection mode remaining amount detection is performed, the toner consumption stored in the storage unit 26 is obtained by multiplying the change amount of the detected light passing amount by the correction coefficient corresponding to the toner consumption amount stored in the storage unit 26. In addition to the quantity, it is stored in the storage means 26 and its value is used as the toner consumption.

  The toner remaining amount detection sequence in this embodiment will be described with reference to the flowchart of FIG.

The process cartridge B includes a storage unit 26. The storage unit 26 includes T, which is the number of printed sheets after the high-accuracy residual detection mode, toner consumption amount P (T) in the normal residual detection mode, and toner remaining amount detection. The toner consumption amount Z derived by the sequence is stored.
Sequence start.
S1: Toner remaining amount detection is started.
S2: Determine the number of printed sheets T <100 after the high accuracy residual check mode.
S3: When T ≧ 100, the remaining toner amount is detected in the high-accuracy remaining detection mode, and the toner consumption is calculated. To reset T, which is the number of printed sheets after the high-accuracy residual detection mode, T = 0 is set.
S4: When T <100, the remaining toner amount is detected in the normal remaining detection mode, the toner consumption is calculated, and written in P (T).
S5: Toner consumption is calculated using the correction coefficient. Specifically, calculated toner consumption below = {P (T) −P (T−1)} × correction coefficient + Z
As the correction coefficient, the correction coefficient corresponding to the consumption transition of Z is selected from Table 2.
S6: T = T + 1.
S7: The toner consumption value calculated in S3 and S5 is written in Z.
End of sequence.

  In this embodiment, by performing this toner remaining amount detection sequence, even if the accuracy in the normal residual detection mode is low, the high accuracy residual detection mode is updated every 100 sheets and the correction to the normal residual detection mode is executed. Therefore, the remaining amount of toner can be sequentially detected with high accuracy by the light transmission type remaining amount detecting device.

  In this embodiment, the relationship between the image formation (printing) speed and the stirring speed is not mentioned, but image formation is performed at a plurality of printing speeds corresponding to a plurality of stirring driving speeds according to the type of the recording medium. Also in the apparatus, substantially the same effect can be obtained by performing the high-accuracy residual detection mode in the above-described toner remaining amount detection sequence while image formation is not being performed.

  In this embodiment, the interval according to the number of printed sheets is used as the timing for performing the high-accuracy residual detection mode. However, it is more effective to use the integrated image formation time including other sequences.

  The present invention can also be applied to a case where the image forming apparatus is not of a process cartridge type, and can achieve the same effects as the present embodiment.

Example 2
Next, another embodiment of the image forming apparatus according to the present invention will be described.

  The present embodiment is characterized in that, in the image forming apparatus A and the process cartridge B described in the first embodiment, the timing for performing the remaining toner amount detection sequence is changed and the same effect as the first embodiment is obtained. Therefore, in this embodiment, the description of the image forming apparatus A and the process cartridge B described in Embodiment 1 is omitted.

  In the present embodiment, the variance is calculated every time the normal residual detection mode is performed 10 times in the first embodiment, and the high-accuracy residual detection mode is executed according to the value. In this embodiment, the threshold value for performing the remaining toner amount detection sequence, the remaining toner amount detection accuracy, the image adverse effect (thinning density due to a decrease in stirring speed), and the average interval (number of printed sheets) at which the high accuracy residual detection mode is performed. The relationship is shown in Table 3 below.

  Table 3 shows that the residual accuracy decreases when the variance value serving as the threshold is set large, and the image defect occurs when it is set small.

  Since it is better that the average interval in which the high-accuracy residual check mode is performed is shorter, in this embodiment, variance ≦ 50 is selected as the variance threshold.

  The remaining toner amount detection sequence in this embodiment will be described with reference to the flowchart of FIG.

The process cartridge B includes a storage unit 26. The storage unit 26 includes T, which is the number of printed sheets after the calculation of the dispersion of consumption 10 times in the normal residual detection mode, and the toner consumption P ( T) and the toner consumption amount Z derived by the toner remaining amount detection sequence are stored.
Sequence start.
S1: Toner remaining amount detection is started.
S2: Determine the number of printed sheets T <10 after the high-accuracy residual inspection mode.
S3: When T ≧ 10, the variance of P (0) to P (9) is calculated, and the variance calculated value ≦ 50 is determined.
S4: When the dispersion calculation value> 50, the remaining toner amount is detected in the high-accuracy remaining detection mode, and the toner consumption is calculated. To reset T, which is the number of printed sheets after the high-accuracy residual detection mode, T = 0 is set.
S5: If T <10 in S2 or the calculated dispersion value ≦ 50 in S4, the remaining toner amount is detected in the normal remaining detection mode, and the toner consumption is calculated and written in P (T).
S6: Toner consumption is calculated using the correction coefficient. Specifically, calculated toner consumption below = {P (T) −P (T−1)} × correction coefficient + Z
As the correction coefficient, the correction coefficient corresponding to the consumption transition of Z is selected from Table 2.
S7: T = T + 1.
S8: The value of the toner consumption calculated in S3 and S5 is written in Z.
End of sequence.

  In this embodiment, by performing this toner remaining amount detection sequence, even if the accuracy in the normal residual detection mode is low, the high-accuracy residual detection mode is changed every time the dispersion in the normal residual detection mode is large (the variation becomes large). Since it is updated and the correction to the normal residual detection mode is executed, it is possible to sequentially detect the remaining amount of toner with high accuracy by the light transmission type residual amount detection device.

  In this embodiment, the relationship between the printing speed and the stirring speed is not mentioned, but in an apparatus that performs image formation at a plurality of printing speeds corresponding to a plurality of stirring driving speeds according to the type of the recording medium, By performing the high-accuracy residual detection mode in the above-described toner remaining amount detection sequence while image formation is not being performed, substantially the same effect can be obtained.

  The present invention can also be applied to a case where the image forming apparatus is not of a process cartridge type, and can achieve the same effects as the present embodiment.

Example 3
In the present embodiment, in the image forming apparatus A described in the first embodiment, the mounting portion (not shown) for mounting the four process cartridges B arranged in parallel in the vertical direction as shown in FIG. The present invention is characterized by being applied to an in-line full-color image forming apparatus. Each process cartridge B, that is, the process cartridges BY, BM, BC, and BK of Y color, M color, C color, and K color, have the same configuration as the process cartridge B described in the first embodiment. 1, the mounting portion of the image forming apparatus main body 100 can be attached to and detached from the image forming apparatus main body 100.

  Although not shown in FIG. 7, the image forming apparatus A and each process cartridge B according to the first embodiment are also applied to the image forming apparatus A and each process cartridge B (BY, BM, BC, BK) according to the present embodiment. Is provided with a developer remaining amount detecting device having the same configuration and function as the above.

  With reference to FIG. 7, the configuration and operation of the color image forming apparatus A of the present embodiment will be described. The color image forming apparatus A of this embodiment is used by being connected to a host 314 such as a personal computer.

  The controller unit 333 processes a print request signal and image data from the host 314, and controls the scanner 303 (303Y, 303M, 303C, 303K) that is an exposure unit, whereby the image carrier that rotates in the direction of the arrow Ra in the figure. An electrostatic latent image is formed on a photosensitive drum 301 (301Y, 301M, 301C, 301K) as a body.

  The photosensitive drum 301 (301Y, 301M, 301C, 301K) provided in each process cartridge B (BY, BM, BC, BK) is a photosensitive drum 301 (301Y, 301M, 301C, 301K) which is a charging unit. It is uniformly charged by a roller-shaped charging member pressed against the surface, that is, a DC contact charging roller (charging roller) 302 (302Y, 302M, 302C, 302K). A DC voltage fixed to a predetermined value as a charging bias is applied to the charging roller 302 (Y, M, C, K), and the surface of the photosensitive drum 301 (301Y, 301M, 301C, 301K) is uniformly made negative. To charge. The charging roller 302 (302Y, 302M, 302C, 302K) is driven to rotate by the rotation of the photosensitive drum 301 (301Y, 301M, 301C, 301K) in the direction of arrow Rd in the drawing. The charging roller 302 (302Y, 302M, 302C, 302K) abuts over substantially the entire length of the photosensitive drum 301 (301Y, 301M, 301C, 301K) in the longitudinal direction (direction perpendicular to the conveyance direction of the recording medium 306). Has been.

  The photosensitive drum 301 (301Y, 301M, 301C, 301K) uniformly charged by the charging roller 302 (302Y, 302M, 302C, 302K) is supplied from a scanner 303 (303Y, 303M, 303C, 303K) as an exposure unit. Is exposed to a laser beam, and an electrostatic latent image is formed on the surface thereof. The scanner 303 (303Y, 303M, 303C, 303K) includes a laser light source, a polygon mirror, a lens system, and the like, and scans and exposes the photosensitive drum 301 (301Y, 301M, 301C, 301K) under the control of the controller unit 333. To do.

  Thereafter, the electrostatic latent image is visualized as a toner image by being supplied with a developer by a developing device 304 (304Y, 304M, 304C, 304K) which is a developing unit.

  That is, the developing device 304 (304Y, 304M, 304C, 304K) contains a developer containing negatively charged nonmagnetic toner (toner) of Y color, M color, C color, and K color, respectively, as a one-component developer. A toner container 321 (321Y, 321M, 321C, 321K). In this embodiment, a substantially spherical toner having a high viscoelasticity and a low viscoelasticity and a volume average particle diameter of about 6 μm, which enables high-speed printing, was used as the toner.

  A part of the toner container 321 (321Y, 321M, 321C, 321K) facing the photoconductor drum 301 (301Y, 301M, 301C, 301K) is the length of the photoconductor drum 301 (301Y, 301M, 301C, 301K). A developing roller 323 (323Y, 323M, 323C, 323K), which is a roller-shaped developer carrier constituting the developing means, is disposed in the opening in substantially the entire direction. The developing roller 323 (323Y, 323M, 323C, 323K) is predetermined on the photosensitive drum 301 (301Y, 301M, 301C, 301K) positioned at the upper left in the drawing of the developing device 304 (304Y, 304M, 304C, 304K). It is pressed and contacted so as to have an intrusion amount, and is driven to rotate in the direction of arrow Rb in the figure.

  To the lower right of the developing roller 323 (323Y, 323M, 323C, 323K) in the drawing, developer is supplied to the developing roller 323 (323Y, 323M, 323C, 323K), and undeveloped toner is supplied to the developing roller 323 (323Y). 323M, 323C, 323K), elastic rollers 324 (324Y, 324M, 324C, 324K) are in contact with each other. The elastic roller 324 (324Y, 324M, 324C, 324K) is rotatably supported by the toner container 321 (321Y, 321M, 321C, 321K). The elastic roller 324 (324Y, 324M, 324C, 324K) is a rubber sponge roller from the viewpoint of supplying toner to the developing roller 323 (Y, M, C, K) and stripping off undeveloped toner. It is rotationally driven in the same direction as the H.323 (323Y, 323M, 323C, 323K) (arrow Rc direction in the figure).

  The developing device 304 (304Y, 304M, 304C, 304K) is a developing blade 325 (325Y, 325Y) serving as a developer layer thickness regulating member that regulates the amount of toner carried on the developing roller 323 (323Y, 323M, 323C, 323K). 325M, 325C, 325K). The developing blade 325 (325Y, 325M, 325C, 325K) is made of an elastic phosphor bronze metal thin plate, and the vicinity of the free end is the outer peripheral surface of the developing roller 323 (323Y, 323M, 323C, 323K). It is provided so as to come into contact with surface contact. The toner carried on the developing roller 323 (323Y, 323M, 323C, 323K) by sliding with the elastic roller 324 (324Y, 324M, 324C, 324K) is developed with a developing blade 325 (325Y, 325M, 325C, 325K). When passing through the abutting portion, electric charge is imparted by frictional charging and the thin layer is regulated.

  In the developing device 304 (304Y, 304M, 304C, 304K) having such a configuration, a DC voltage fixed to a predetermined value as a developing bias is applied to the developing roller 323 (323Y, 323M, 323C, 323K). . Thus, in this embodiment, the exposed portion on the surface of the uniformly charged photosensitive drum 301 (301Y, 301M, 301C, 301K) where the negative charge is attenuated is developed by reversal development.

On the other hand, an electrostatic transfer belt 341 that circulates and moves so as to face and contact all the photosensitive drums 301 (301Y, 301M, 301C, and 301K) is provided. The transfer belt 341 is a film-like member having a volume resistivity of 10 ¹¹ to 10 ¹⁴ Ω · cm and a thickness of about 150 μm.

  Then, the recording medium 306 is separated and fed from the recording medium container 316 by a supply roller 316a and the like, and is temporarily stopped by a registration roller 316b. The registration roller 316b synchronizes the recording position of the recording medium 306 with the formation timing of the toner image on the photosensitive drum 301 (Y, M, C, K), and transfers the transfer roller 305 (305Y, 305M, 305C, 305K) and the photosensitive drum 301 (301Y, 301M, 301C, 301K), the recording medium 306 is sent out to the facing portion (transfer portion).

  In this way, the recording medium 306 is sequentially conveyed to the Y, M, C, and K transfer positions by the transfer belt 341, and each color on the photosensitive drum 301 (301Y, 301M, 301C, 301K). The toner images are sequentially transferred onto the recording medium 306, and conveyed upward while laminating the toner images.

  The recording medium 306 onto which the toner image has been transferred is conveyed to the fixing device 309. Here, the unfixed toner image on the recording medium 306 is permanently fixed to the recording medium 306 by heat and pressure. Thereafter, the recording medium 306 is discharged out of the apparatus by a discharge roller 316c or the like.

  Further, untransferred toner remaining on the photosensitive drum 301 (301Y, 301M, 301C, 301K) without being transferred is cleaned by a cleaning unit (cleaner) 307 (307Y, 307M, 307C, 307K). That is, the cleaner 307 (307Y, 307M, 307C, 307K) removes the transfer residual toner from the photosensitive drum 301 (301Y, 301M, 301C, 301K) by the cleaning blade 307a (307aY, 307aM, 307aC, 307aK) as a cleaning member. It is scraped off and stored in a waste toner container 308 (308Y, 308M, 308C, 308K). The cleaned photosensitive drum 301 (301Y, 301M, 301C, 301K) is again used for image formation.

  Each process cartridge B (BY, BM, BC, BK) is provided with storage means 326 (326Y, 326M, 326C, 326K). As the storage unit 326 (326Y, 326M, 326C, 326K), for example, any form such as a contact nonvolatile memory, a contactless nonvolatile memory, and a volatile memory having a power source can be used. In this embodiment, a non-contact nonvolatile memory 326 (326Y, 326M, 326C, 326K) is mounted on each process cartridge B as a storage means. The non-contact non-volatile memory 326 (326Y, 326M, 326C, 326K) has an antenna (not shown) as information transmission means on the memory side, and wirelessly includes a control means (CPU) 332 provided in the image forming apparatus main body. Can read and write information. In this embodiment, the CPU 332 stores information in the apparatus main body side, information in the memory 326 (326Y, 326M, 326C, 326K), and information in the storage unit 326 (326Y, 326M, 326C, 326K). It has a function as a memory. Note that the storage means 326 (326Y, 326M, 326C, 326K) provided in the process cartridge B stores the toner consumption amount and the number of printed sheets by detecting the remaining amount of toner in the corresponding process cartridge B.

  In this embodiment, the toner remaining amount detection sequence of Embodiments 1 and 2 is executed independently for each of the process cartridges B (BY, BM, BC, BK), whereby the process cartridge B (BY, BM) is executed. , BC, BK) can perform sequential detection of the remaining amount of toner with high accuracy. That is, also in the present embodiment, it is possible to achieve the same effect as in the first and second embodiments.

  In this embodiment, as described above, the inline full-color laser beam printer is used. However, the same effect can be obtained in a full-color laser beam printer using a rotary system.

1 is a schematic cross-sectional view of an embodiment of an image forming apparatus according to the present invention. It is a schematic sectional drawing of the process cartridge which concerns on this invention. FIG. 5 is a perspective view of a developing device unit showing a configuration of light transmission type toner remaining amount detection in a process cartridge according to the present invention. 6 is a graph showing a relationship between a toner consumption amount in one embodiment of the image forming apparatus according to the present invention and a transit time during which the detection light L of the developer remaining amount detection device passes through the toner container. 3 is a flowchart illustrating the operation of an embodiment of the image forming apparatus according to the present invention. 6 is a flowchart illustrating the operation of another embodiment of the image forming apparatus according to the present invention. It is a schematic sectional drawing of the other Example of the image forming apparatus which concerns on this invention.

Explanation of symbols

1,301 Photosensitive drum (image carrier)
2,302 Charging roller (charging means)
3, 303 Scanner (exposure means)
4,304 Developing device (developing means)
5,305 Transfer roller (transfer means)
7,307 Cleaner (cleaning means)
21, 321 Toner container 23, 323 Developing roller (developer carrier)
26, 326 non-contact memory (storage means)
28, 328 Stirring member (stirring means)
30 Developer remaining amount detection device 30a Light emitting element (sensor means)
30b Light receiving element (sensor means)
32 CPU (control means)

Claims (8)

An image carrier, a developer carrier for carrying and transporting a developer for developing a latent image formed on the image carrier to form a toner image, a developer containing portion containing the developer, A developer remaining amount detection having a stirring unit that can change a drive for stirring the developer in the developer accommodating portion, and a sensor means for detecting the remaining amount of the developer in the developer accommodating portion. In an image forming apparatus comprising: an apparatus; a storage unit that updates and stores a developer remaining amount; and a transfer unit that transfers the toner image to a recording medium.
The developer remaining amount detecting device has a developer remaining amount detecting mode by the developer remaining amount detecting device corresponding to a plurality of stirring drive speeds of the stirring means,
The image forming apparatus changes the stirring driving speed of the stirring unit to a predetermined speed in accordance with a predetermined timing, stores the developer remaining amount in the developer remaining amount detection mode corresponding thereto in the storage unit, and At the time of formation, the developer remaining amount in the developer remaining amount detection mode corresponding to the stirring drive speed of the stirring unit during image formation is corrected based on the value of the storage unit, and stored in the storage unit. An image forming apparatus characterized in that a value stored in a storage means is used as a developer remaining amount.   The image forming apparatus according to claim 1, wherein the image forming apparatus has a plurality of image forming speeds according to the type of the recording medium, and can form an image at the plurality of stirring drive speeds corresponding to the respective image forming speeds. Image forming apparatus.   3. The image forming apparatus according to claim 1, wherein the predetermined timing is a predetermined number of image forming sheets or a predetermined image forming integrated time. 4.   The predetermined timing is a case where a predetermined number of detections is detected by a developer remaining amount detection mode corresponding to the stirring drive speed of the stirring unit during image formation, and the dispersion of the remaining amount of developer becomes a predetermined value or more. The image forming apparatus according to claim 1, wherein the image forming apparatus is an image forming apparatus.   The developer remaining amount detecting device includes a light emitting element that emits detection light that passes through the developer accommodating portion, and a light receiving element that receives detection light emitted from the light emitting element, and in a stirring state by the stirring unit. Light that is emitted from the light emitting element and passes without being blocked by the developer in the developer accommodating portion is detected by the light receiving element, and the developer remaining in the developer accommodating portion is detected based on the detection output of the light receiving element. The image forming apparatus according to claim 1, wherein the amount is measured.   At least the image carrier, the developer carrier, the developer container, the agitation unit, and the storage unit are integrated into a process cartridge, and the process cartridge with respect to the image forming apparatus main body The image forming apparatus according to claim 1, wherein the image forming apparatus is detachable.   The image forming apparatus according to claim 6, wherein the storage unit stores at least an image forming number and a toner consumption amount.   The image forming apparatus according to claim 6, wherein a plurality of the process cartridges containing developers of different colors are provided.

Images