JP2006071790A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus capable of detecting a state that the remaining amount of a developer is small in a short period of time and also detecting an accurate developer remaining amount toward no developer remaining amount. <P>SOLUTION: A developer remaining amount detecting device has a rough detection mode in which the remaining amount of a developer T in a developer storage part 21 is roughly detected and a precise detection mode in which the remaining amount of the developer T in the developer storage part 21 is accurately detected, and the developer remaining amount detecting device performs the precise detection mode after detecting the remaining amount of the developer T in the rough detection mode to measure the developer remaining amount in the developer storage part 21. <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.

  In other words, the detection light does not pass if the toner container is in a large amount of toner. Conversely, if the toner is consumed, the detection light starts to pass and the detection time becomes longer. If the detection light passage time when the toner in the toner container runs out is set as a threshold value in advance, when the detection light passage time passing through the toner container exceeds the threshold value, The user can be notified that the toner in the container 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, when the image forming speed (process speed) is increased and the printing productivity (printing speed) is improved by using the above configuration, a sheet member, that is, a stirring member according to the image forming speed in order to stabilize the image. When the rotation speed of the toner was increased, the toner immediately covered the light transmission window, the time for the detection light to pass through the toner container became unstable, and the detection accuracy of the remaining amount of toner became unstable.

  This is because when the stirring drive speed of the stirring member is fast, the toner in the toner container is always in the cloud state, and when the stirring drive speed is slow, the toner stays at the bottom of the toner container after entering the cloud state. is there. That is, when the agitation drive speed is high, the toner is always in a cloud state and it is difficult for the detection light to pass through. When the agitation drive speed is slow, the toner is in a cloud state with a low density and then enters the bottom of the toner container. This is because the detection light is easy to pass because it stays (passes during a low-density cloud state).

  As described above, in recent image forming apparatuses, it is required to improve the printing productivity, and it is necessary to maintain the toner transportability in order to improve the image stability. Will be accelerated. Then, the toner is always in a cloud state, and it is difficult for the detection light to pass through, so that the detection accuracy of the remaining amount of toner becomes unstable. As a result, the user is inaccurately notified of the remaining amount of toner that can be printed, and a sufficient period for the user to prepare the next developing device cannot be obtained, resulting in a printing stop period due to no remaining toner. There is a fear. Such a problem may cause a more serious situation in an image forming apparatus with high printing productivity.

  Accordingly, an object of the present invention is to provide an image forming apparatus capable of detecting a state in which the remaining amount of developer is low in a short time and accurately detecting the remaining amount of developer toward the absence of the remaining amount of developer. Is to provide.

The above object is achieved by the image forming apparatus according to the present invention. In summary, according to a first aspect of the present invention, an image carrier, a developer carrier that carries and transports a developer for developing a latent image formed on the image carrier, and A developer accommodating portion that accommodates the developer, an agitation unit that can vary a drive for agitating the developer in the developer accommodating portion, and a remaining amount of the developer in the developer accommodating portion. A developer remaining amount detecting device having a sensor means for detecting the remaining amount of the developer based on a detection value of the sensor means.
The developer remaining amount detecting device includes a rough detection mode for roughly detecting the remaining amount of the developer in the developer accommodating portion, and a precise detection for accurately detecting the remaining amount of the developer in the developer accommodating portion. With mode,
The developer remaining amount detecting device executes the precise detection mode after the remaining amount of the developer is detected in the rough detection mode, and measures the remaining amount of developer in the developer accommodating portion. An image forming apparatus is provided.

According to the second aspect of the present invention, the developer container containing a developer for developing the latent image formed on the image carrier, and the developer in the developer container are agitated. A plurality of developing devices including a plurality of developing devices each having a driving means that can be driven, and a sensor means for detecting the remaining amount of the developer in the developer containing portion of each developing device. In the image forming apparatus that includes a remaining amount detection device, wherein each of the developer remaining amount detection devices detects the remaining amount of the developer of each of the developing devices based on the detection value of the respective sensor means.
The developer remaining amount detecting device includes a rough detection mode for roughly detecting the remaining amount of the developer in the developer accommodating portion, and a precise detection for accurately detecting the remaining amount of the developer in the developer accommodating portion. With mode,
When the remaining amount of developer in any of the developing devices is detected in the rough detection mode, the remaining developer detecting device executes the precise detection mode in all the remaining developer detecting devices. The developer remaining amount detecting device determined to have the least amount of developer remaining in the developer container when the developer remaining amount detecting device continues in the rough detection mode for a predetermined period. An image forming apparatus is provided.

  The image forming apparatus of the present invention can detect the remaining amount of developer without deteriorating the printing productivity until the detection light passage time is obtained in the coarse residual detection mode while forming an image in a high-speed printing state. Even when the developer in the developer container is consumed and the remaining amount becomes low, the remaining amount of developer can be detected with high accuracy without losing the print productivity as much as possible. .

  In addition, since the storage means is provided in the process cartridge, the remaining amount of developer can be detected with high accuracy even when the process cartridge being used is detached from the image forming apparatus and used in another image forming apparatus. It can be carried out.

  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.

  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 agitating member 28 a and the second agitating 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 this embodiment, the first stirring member 28a and the second stirring member 28b are connected to the developing roller 23 by a gear (not shown), and together with driving of the developing roller 23 by a driving unit provided in the image forming apparatus main body 100, A configuration in which the first stirring member 28a and the second stirring member 28b are variably driven 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, when the toner T is in a large amount in the toner container 21, the detection light L does not pass. Conversely, when the toner T is consumed, the detection light L is obtained, and the toner T is consumed. The transit time becomes longer. If the passage time of the detection light L when the toner T in the toner container 21 runs out is set as the threshold value Y in advance, the passage time of the detection light L that passes through the toner container 21 is a threshold value. When Y is reached, 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, which sequentially notifies the remaining amount of toner T in the toner container 21.

  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 amount of toner consumed in the toner container 21 and the passage time during which the detection light L of the developer remaining amount detecting device has passed through the toner container 21 with respect to the second stirring speed.

  In this example, the stirring speed at speed A was 40 rpm, and the stirring speed at speed B was 80 rpm. At speed B, two data obtained at speed B are entered as speed B-1 and speed B-2. When the toner consumption amount 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. When the toner consumption amount is 100%, the toner T in the toner container 21 is consumed and the process is performed. This indicates that the cartridge B is to be replaced.

  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 passes through the toner container 21. In the state where the toner T in the toner container 21 is large, the detection light L Since L is completely shielded by the toner T, it cannot pass through the toner container 21. When the toner T in the toner container 21 is consumed, the detection light L starts to pass through a little, but the detection light passing time is obtained. Then, as the toner T in the toner container 21 is further consumed and the toner T decreases in the toner container 21, the passing time for the detection light L to pass through the toner container 21 increases (= long). Here, the state in which the detection light L does not pass through the toner container 21 is 0, the state in which the detection light L continues to pass through the toner container 21 is 100, and the process cartridge B is replaced at 100. Indicates.

  As shown in FIG. 4, in this embodiment, when the remaining amount of toner is very large, the detection light is not obtained and the detection light passing time is zero regardless of the stirring drive speed. The detection light starts to be obtained when the toner is consumed and the toner consumption is about 60%. In this state, the detection light passing time varies depending on the stirring drive speed.

  In particular, at the speed B where the stirring drive speed is high, the variation in the passage time becomes large. On the contrary, in the case of the speed A where the stirring speed is slow, a stable detection light passing time can be obtained. 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 fast, the toner is always in a cloud state and has a high density, so that it is difficult for detection light to pass through and a stable transit time cannot be obtained. When the remaining amount of toner is large and the stirring drive speed is slow, the toner stays at the bottom of the toner container after entering the low density cloud state, and therefore the detection light easily passes (passes during the low density cloud state) and A stable transit time is obtained.

  When the remaining amount of toner is low and the stirring drive speed is fast, the toner is always in the cloud state, but the density of the toner is small and the detection light easily passes. As indicated by the toner consumption amount 100% at speed B-2, the remaining amount of toner determined from the passage time is still in an image forming (printing) possible state.

  On the contrary, when the speed is A, the passage time of the detection light stably follows the toner consumption amount, so that the remaining amount of toner can be accurately detected. As described above, there is an advantage that accurate toner remaining amount detection can be achieved by setting the slow stirring speed A. However, since the stirring speed is slow, the sheet member 28a2 has a long cleaning interval between the light transmission windows 26a and 26b. As a result, it takes a long time to detect the remaining amount of toner (hereinafter referred to as “precision residual detection mode”).

  In this embodiment, in order to improve printing productivity, it is necessary to transport as much toner as possible to the elastic roller 24 and the developing roller 23 in order to enable high-speed printing. using. Therefore, while the image formation is performed in the high-speed printing state, the stirring speed is high at the speed B, and the sheet member 28a2 has the advantage that the cleaning time of the light transmission windows 26a and 26b is short, so that the time for detecting the remaining amount of toner is short. The detection results have a variation (hereinafter referred to as “rough residual detection mode”).

  Here, in this embodiment, the remaining amount of toner is detected in the coarse residual detection mode until the detection light passage time is obtained from the new state of the process cartridge, and then the detection light passage time in the coarse residual detection mode. Is obtained, and after the accurate residual amount mode is obtained and an accurate toner remaining amount is obtained, the image formation (printing) is performed again in the rough residual mode, and then the precise residual mode is executed. . By repeating this and obtaining an accurate remaining amount of toner while gradually reducing the predetermined number of sheets according to the remaining amount of toner obtained from the precision remaining detection mode, it is possible to accurately obtain the timing when the process cartridge 10 is to be replaced. be able to.

The toner remaining amount detection sequence in this embodiment will be described with reference to the flowchart of FIG.
Sequence start.
S1: Toner remaining amount detection is started.
S2: The rough residual detection mode is executed, and it is determined whether or not the detection light passing time is obtained. When the detection light is obtained, the process proceeds to S3, and when the detection light is not obtained, the coarse residual detection mode is continued.
S3: The remaining amount of toner is detected in the precision residual detection mode, and the detection light passing time Ts is measured. In the present embodiment, the precision residual detection mode is the rotation after the image forming operation is completed, or the detection light passes by reducing the stirring speed to the speed A in the non-image area where the conveyance of the recording medium is temporarily interrupted. Time Ts is measured.
S4: When Ts ≦ 30, the process proceeds to S5, and when 30 <Ts, the process proceeds to S10.
S5: The number N of print intervals until the next precision residual inspection mode is executed is set to 100 (N = 100).
S6: When the printing interval sheet number N is set to 100 sheets, a display for notifying toner is displayed on the display unit of the image forming apparatus main body.
S7: Raise the stirring speed to speed B again and execute the coarse residual detection mode. At this time, if there is a recording medium whose conveyance is temporarily interrupted, the conveyance of the recording medium is started again, and the coarse residual detection mode is executed simultaneously with the image formation.
S8: Every time one printing operation is executed, the printing interval number N is updated to N = N-1.
S9: The value of the printing interval number N is determined. If 0 <N, the rough residual inspection mode is continued. When N = 0, the process proceeds to S3 in order to execute the precision residual inspection mode again.
S10: The remaining toner amount is detected in the precision residual detection mode. If the detection light passage time Ts is 30 <Ts ≦ 50, the process proceeds to S11. If 50 <Ts, the process proceeds to S12.
S11: The printing interval number N until the next precision residual inspection mode is executed is set to 80 (N = 80), and the process proceeds to S7.
S12: The remaining toner amount is detected in the precision residual detection mode. If the detection light passage time Ts is 50 <Ts ≦ 70, the process proceeds to S13. If 70 <Ts, the process proceeds to S14.
S13: The number N of printing intervals until the next precision residual inspection mode is executed is set to 50 (N = 50), and the process proceeds to S7.
S14: The remaining toner amount is detected in the precision residual detection mode. If the detection light passage time Ts is 70 <Ts ≦ 90, the process proceeds to S15. If 90 <Ts, the process proceeds to S16.
S15: The number N of print intervals until the next precision residual inspection mode is executed is set to 30 (N = 30), and the process proceeds to S7.
S16: The remaining toner amount is detected in the precision residual detection mode. If the detection light passage time Ts is 90 <Ts100, the process proceeds to S17. If Ts = 100, the process proceeds to S18.
S17: The number N of printing intervals until the next precision residual inspection mode is executed is set to 10 (N = 10), and the process proceeds to S7.
S18: As a result of detecting the remaining amount of toner in the precision residual detection mode, since the detection light passing time Ts is 100, the process cartridge has run out of toner, so the display unit of the image forming apparatus main body is warned that there is no toner. Display.
End of sequence.

  In this embodiment, by performing this toner remaining amount detection sequence, the toner remaining amount is not deteriorated until the passing time of the detection light is obtained in the rough remaining detection mode while the image is formed in the high-speed printing state. Quantity detection is possible. Even when the toner in the toner container is consumed and the remaining amount becomes low, the remaining amount of toner can be detected with high accuracy without losing the printing productivity as much as possible.

  In addition, what is necessary is just to select the suitable value according to the apparatus to be used for the passage time Ts of the detection light and the printing interval number N in this embodiment.

  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. FIG. 6 shows a schematic configuration of the image forming apparatus of this embodiment. The image forming apparatus A and the process cartridge B shown in FIG. 6 have the same configuration as the image forming apparatus A and the process cartridge B of Embodiment 1 described with reference to FIGS. Accordingly, members having the same functions and actions in FIG. 6 are denoted by the same reference numerals, detailed description thereof is omitted, and the description of the first embodiment is cited.

  In other words, the present embodiment has a configuration in which the timing for performing the precision residual detection mode is changed in the image forming apparatus A and the process cartridge B described in the first embodiment, and this embodiment is also equivalent to the first embodiment. It has the effect of.

  In this embodiment, the number of rotations of the developing roller 23 interlocked with the rotation of the agitating member 28 is stored in the storage means provided in the process cartridge B, and the precision residual detection mode is performed based on the stored information.

  Referring to FIG. 6, in this embodiment, in the image forming apparatus A, 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. 100 is detachable.

  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) as information transmission means on the memory side, and communicates with a control means (CPU) 32 provided in the image forming apparatus main body 100 wirelessly, thereby Reading and writing are possible. In this embodiment, the CPU 32 has a function as an information transmission unit on the apparatus body side, a unit for reading and writing information in the memory 26, and a memory for storing information in the storage unit 26.

  The storage means 26 provided in the process cartridge B stores the total number of rotations of the developing roller 23 since the use of the process cartridge B is started.

  In this embodiment, the remaining toner amount is detected in the coarse residual detection mode until the detection light passage time is obtained from the new state of the process cartridge B, and then the detection light passage time is obtained in the coarse residual detection mode. When the printing is performed again in the rough residual detection mode after the accurate residual detection mode is obtained and the accurate residual amount is obtained, the developing roller B rotates. Perform the precision residual mode. By repeating this and obtaining an accurate toner remaining amount while gradually decreasing the predetermined number of revolutions according to the toner remaining amount obtained from the precision residual detection mode, the timing at which the process cartridge B is replaced can be accurately determined. It is characterized by obtaining.

The toner remaining amount detection sequence in this embodiment will be described with reference to the flowchart of FIG.
Sequence start.
S1: Toner remaining amount detection is started.
S2: The rough residual detection mode is executed, and it is determined whether or not the detection light passing time is obtained. When the detection light is obtained, the process proceeds to S3, and when the detection light is not obtained, the coarse residual detection mode is continued.
S3: The remaining amount of toner is detected in the precision residual detection mode, and the detection light passing time Ts is measured. In the present embodiment, the precision residual detection mode is the rotation after the image forming operation is completed, or the detection light passes by reducing the stirring speed to the speed A in the non-image area where the conveyance of the recording medium is temporarily interrupted. Time Ts is measured.
S4: The total rotation speed R of the developing roller 23 is read from the storage means 26 and stored in the memory unit of the CPU 32 as R0.
S5: If Ts ≦ 30, the process proceeds to S6, and if 30 <Ts, the process proceeds to S11.
S6: The remaining detection start developing roller rotation speed R1 for executing the next precise remaining detection mode is set to R1 = R0 + 1000, and the remaining detection start developing roller rotation speed R1 is stored in the CPU 32.
S7: At the time when the remaining inspection start developing roller rotation speed R1 is set, a display for notifying the absence of toner is performed on the display unit of the image forming apparatus main body.
S8: The stirring speed is increased again to speed B, and the coarse residual detection mode is executed. At this time, if there is a recording medium whose conveyance is temporarily interrupted, the conveyance of the recording medium is started again, and the coarse residual detection mode is executed simultaneously with the image formation.
S9: The total rotation speed R of the developing roller 23 is read from the storage means 26 during the printing operation.
S10: The current total rotation speed R of the developing roller is compared with the remaining detection start developing roller rotation speed R1 stored in the CPU 32. If R <R1, the rough residual detection mode is continued. When R ≧ R1, the process proceeds to S3 in order to execute the precision residual inspection mode again.
S11: The remaining toner amount is detected in the precision residual detection mode. If the detection light passage time Ts is 30 <Ts ≦ 50, the process proceeds to S12. If 50 <Ts, the process proceeds to S13.
S12: The remaining detection start developing roller rotation speed R1 for executing the next precise remaining detection mode is set to R1 = R0 + 800, the remaining detection start developing roller rotation speed R1 is stored in the CPU 32, and the process proceeds to S8.
S13: The remaining toner amount is detected in the precision residual detection mode. If the detection light passage time Ts is 50 <Ts ≦ 70, the process proceeds to S14. If 70 <Ts, the process proceeds to S15.
S14: The remaining detection start developing roller rotation speed R1 for executing the next precise remaining detection mode is set to R1 = R0 + 500, the remaining detection start developing roller rotation speed R1 is stored in the CPU 32, and the process proceeds to S8.
S15: The remaining toner amount is detected in the precision residual detection mode. If the detection light passage time Ts is 70 <Ts ≦ 90, the process proceeds to S16. If 90 <Ts, the process proceeds to S17.
S16: The remaining detection start developing roller rotation speed R1 for executing the next precise remaining detection mode is set to R1 = R0 + 300, the remaining detection start developing roller rotation speed R1 is stored in the CPU 32, and the process proceeds to S8.
S17: The remaining toner amount is detected in the precision residual detection mode. If the detection light passage time Ts is 90 <Ts100, the process proceeds to S18. If Ts = 100, the process proceeds to S19.
S18: The remaining detection start developing roller rotation speed R1 for executing the next precise remaining detection mode is set to R1 = R0 + 100, the remaining detection start developing roller rotation speed R1 is stored in the CPU 32, and the process proceeds to S8.
S19: As a result of detecting the remaining amount of toner in the precision residual detection mode, since the detection light passing time Ts is 100, the process cartridge has run out of toner. Display.
End of sequence.

  In this embodiment, by performing this toner remaining amount detection sequence, the toner remaining amount is not deteriorated until the passing time of the detection light is obtained in the rough remaining detection mode while the image is formed in the high-speed printing state. Quantity detection is possible. Even when the toner in the toner container is consumed and the remaining amount becomes low, the remaining amount of toner can be detected with high accuracy without losing the printing productivity as much as possible.

  The detection light passing time Ts and the residual detection start developing roller rotation speed R1 according to the present embodiment may be set to suitable values according to the apparatus used. In this embodiment, the rotation speed of the developing roller 23 is used as the information stored in the storage unit 26. However, the same effect can be obtained by storing the rotation speed of the stirring member 28 directly related to the detection of the remaining amount of toner.

  Further, in each step (S6, S12, S14, S16, S18) for setting the remaining detection start developing roller rotation speed R1 described above, the set remaining detection start developing roller rotation speed R1 is overwritten according to the storage means 26. By storing, even when the process cartridge B in use is detached from the image forming apparatus A and loaded and used in another image forming apparatus, the current cartridge is detected immediately after the toner remaining amount detection start (S1) shown in FIG. The total rotation speed R of the developing roller is compared with the remaining detection start developing roller rotation speed R1 stored in the storage unit 26, and when R <R1, the rough remaining detection mode is executed. Is possible. In the case of R ≧ R1, in order to execute the precision residual mode again, the process may proceed to S3 to execute the precision residual mode.

  In this embodiment, the number of rotations of the developing roller 23 is used as information stored in the storage unit 26. However, the number N of print intervals until the next precision residual inspection mode described in the first embodiment is executed is stored in the storage unit 26. It is possible to store the toner and perform a toner residual detection sequence similar to that of the present embodiment.

Example 3
In this embodiment, in the image forming apparatus A described in the first embodiment, the image forming apparatus A includes mounting portions (not shown) for mounting 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. 8, the image forming apparatus A and each process cartridge B of the first embodiment are also included in the image forming apparatus A and each process cartridge B (BY, BM, BC, BK) of the present embodiment. Is provided with a developer remaining amount detecting device having the same configuration and function as the above.

  In the inline full-color image forming apparatus as in the present embodiment, the detection light passage time is obtained in the rough residual detection mode while performing image formation in the high-speed printing state by performing the toner remaining amount detection sequence of the first or second embodiment. Until then, the remaining amount of toner can be detected without impairing the printing productivity, which is an advantage of the inline full-color image forming apparatus. Even when the toner in the toner container is consumed and the remaining amount becomes low, the remaining amount of toner can be detected with high accuracy without losing the printing productivity as much as possible.

  The configuration and operation of the color image forming apparatus A of this embodiment will be described with reference to FIG. 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 the present embodiment, the CPU 332 stores information in the apparatus main body, information in the memory 326 (326Y, 326M, 326C, 326K), and information in the storage means 326 (326Y, 326M, 326C, 326K). It has a function as a memory. The storage means 326 (326Y, 326M, 326C, 326K) provided in the process cartridge B stores the total number of rotations of the developing roller 323 since the use of the corresponding process cartridge B is started.

  In this embodiment, the toner remaining amount detection sequence described in the second embodiment is applied.

  The toner remaining amount detection sequence of the present embodiment is in accordance with the contents described in the second embodiment, but the toner remaining amount detection sequence is a process cartridge B (BY, 4) of four colors (Y, C, M, K). BM, BC, BK) are all executed at the same time, and the process cartridge B with the least amount of toner among the four color (Y, C, M, K) process cartridges B (BY, BM, BC, BK). In accordance with the remaining amount of toner, the timing for executing the precision residual inspection mode for all four colors is determined.

The toner remaining amount detection sequence in this embodiment will be described with reference to the flowchart of FIG.
Sequence start.
S1: Toner remaining amount detection is started.
S2: The rough residual detection mode is executed, and it is determined whether or not the detection light passing time is obtained. When the detection light is obtained, the process proceeds to S3, and when the detection light is not obtained, the coarse residual detection mode is continued.
S3: The remaining amount of toner is detected in the precision residual detection mode, and the detection light passing time Ts is measured. In the present embodiment, the precision residual detection mode is the rotation after the image forming operation is completed, or the detection light passes by reducing the stirring speed to the speed A in the non-image area where the conveyance of the recording medium is temporarily interrupted. Time Ts is measured.
S20: As a result of detecting the remaining amount of toner in the precision residual detection mode in S3, it is determined whether there is a process cartridge in which the remaining amount of toner is large and the detection light passage time Ts is Ts = 0, and the passage time Ts is Ts = 0. For the color to be the process cartridge, the process proceeds to S21. If there is no process cartridge in which Ts = 0, the process proceeds to S4.
S21: As a result of detecting the remaining amount of toner in the precision residual detection mode in S3, in the process cartridge of a color having a large amount of remaining toner and the detection light passing time Ts Ts = 0, no processing operation is performed and Ts described later is performed. Toner remaining amount detection will be performed in the remaining detection mode of the process cartridge in which ≠ 0.
S4: The total rotational speed R of the developing roller 323 is read from the storage means 326 of the process cartridge where T ≠ 0, and stored in the storage means 326 of the process cartridge as R0.
S5: If Ts ≦ 30, the process proceeds to S6, and if 30 <Ts, the process proceeds to S11.
S6: The remaining detection start developing roller rotation speed R1 for executing the next precise remaining detection mode is set to R1 = R0 + 1000, and the remaining detection start developing roller rotation speed R1 is stored in the CPU 332.
S7: At the time when the remaining inspection start developing roller rotation speed R1 is set, a display for notifying the absence of toner is performed on the display unit of the image forming apparatus main body.
S22: R1-R of each color of the process cartridge is calculated for each color, and the color with the smallest value of R1-R is selected as the Ct color.
S23: The remaining detection start developing roller rotation speed R1 selected as the Ct color is stored in the CPU 332 as R1 (Ct).
S8: The stirring speed is increased again to speed B, and the coarse residual detection mode is executed. At this time, if there is a recording medium whose conveyance is temporarily interrupted, the conveyance of the recording medium is started again, and the coarse residual detection mode is executed simultaneously with the image formation.
S9: During the printing operation, the total rotation speed R (Ct) of the developing roller 323 is read from the Ct color storage means 326.
S10: The total rotation speed R (Ct) of the current developing roller 323 of Ct color is compared with the remaining detection start developing roller rotation speed R1 (Ct) stored in the CPU 332, and when R (Ct) <R1 (Ct) Continues the coarse residual mode. When R (Ct) ≧ R1 (Ct), the process proceeds to S3 in order to execute the precision residual detection mode again.
S11: The remaining toner amount is detected in the precision residual detection mode. If the detection light passage time Ts is 30 <Ts ≦ 50, the process proceeds to S12. If 50 <Ts, the process proceeds to S13.
S12: The remaining detection start developing roller rotation speed R1 for executing the next precise remaining detection mode is set to R1 = R0 + 800, the remaining detection start developing roller rotation speed R1 is stored in the CPU 332, and the process proceeds to S22.
S13: The remaining toner amount is detected in the precision residual detection mode. If the detection light passage time Ts is 50 <Ts ≦ 70, the process proceeds to S14. If 70 <Ts, the process proceeds to S15.
S14: The remaining detection start developing roller rotation speed R1 for executing the next precise remaining detection mode is set to R1 = R0 + 500, the remaining detection start developing roller rotation speed R1 is stored in the CPU 332, and the process proceeds to S22.
S15: The remaining toner amount is detected in the precision residual detection mode. If the detection light passage time Ts is 70 <Ts ≦ 90, the process proceeds to S16. If 90 <Ts, the process proceeds to S17.
S16: The remaining detection start developing roller rotation speed R1 for executing the next precise remaining detection mode is set to R1 = R0 + 300, the remaining detection start developing roller rotation speed R1 is stored in the CPU 332, and the process proceeds to S22.
S17: The remaining toner amount is detected in the precision residual detection mode. If the detection light passage time Ts is 90 <Ts100, the process proceeds to S18. If Ts = 100, the process proceeds to S19.
S18: The remaining detection start developing roller rotation speed R1 for executing the next precise remaining detection mode is set to R1 = R0 + 100, the remaining detection start developing roller rotation speed R1 is stored in the CPU 332, and the process proceeds to S22.
S19: As a result of detecting the remaining amount of toner in the precision residual detection mode, since the detection light passing time Ts is 100, the process cartridge has run out of toner. Display.
End of sequence.

  This makes it possible to detect the remaining amount of toner without sacrificing printing productivity, which is an advantage of an inline full-color image forming device, until the detection light passage time is obtained in the coarse residual detection mode while forming an image in a high-speed printing state. It becomes. Even when the toner in the toner container is consumed and the remaining amount becomes low, the remaining amount of toner can be detected with high accuracy without losing the printing productivity as much as possible.

  In this embodiment, the rotation speed of the developing roller 323 is used as information stored in the storage unit 326. However, the same effect can be obtained by storing the rotation speed of the stirring member 328 directly related to the toner remaining amount detection. Further, the number N of print intervals until the next precise residual detection mode described in the first embodiment is executed is stored in the storage unit 326, and a toner residual detection sequence similar to that of the present exemplary embodiment can be performed.

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 steel made 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. It is a schematic sectional drawing of the other Example of the image forming apparatus which concerns on this 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. 6 is a flowchart illustrating the operation of another embodiment of the image forming apparatus according to the present 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 (developer container)
23, 323 Development roller (developer carrier)
26, 326 non-contact memory (storage means)
28, 328 Agitating means 30 Developer remaining amount detecting device 30a Light emitting element (sensor means)
30b Light receiving element (sensor means)
32 CPU (control means)

Claims (18)

An image carrier, a developer carrier that carries and transports a developer for developing a latent image formed on the image carrier, a developer container that contains the developer, and the developer container. And a developer remaining amount detecting device having a stirring unit that can change a drive for stirring the developer in the unit, and a sensor unit that detects the remaining amount of the developer in the developer containing unit. In the image forming apparatus for detecting the remaining amount of the developer based on the detection value of the sensor means,
The developer remaining amount detecting device includes a rough detection mode for roughly detecting the remaining amount of the developer in the developer accommodating portion, and a precise detection for accurately detecting the remaining amount of the developer in the developer accommodating portion. With mode,
The developer remaining amount detecting device executes the precise detection mode after the remaining amount of the developer is detected in the rough detection mode, and measures the remaining amount of developer in the developer accommodating portion. 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 through the developer in the developer accommodating portion without being blocked by the developer is detected by the light receiving element, and the development is performed based on the time that the detection light passes through the developer accommodating portion. It is a light transmission method that detects the remaining amount of agent,
The image forming apparatus according to claim 1, wherein the coarse detection mode measures a remaining amount of developer in the developer accommodating portion during image formation.   After executing the fine detection mode, the remaining amount of the developer is detected again in the rough detection mode, and after the rough detection mode is continued for a predetermined period, the fine detection mode is executed again to execute the developer. The image forming apparatus according to claim 1, wherein the remaining amount of the developer in the housing portion is measured.   The image forming apparatus according to claim 3, wherein the predetermined period is variable according to a developer remaining amount in the developer accommodating portion.   The image forming apparatus according to claim 3, wherein the predetermined period is a predetermined number of image forming sheets.   The image forming apparatus according to claim 3, wherein the predetermined period is a time during which the developer carrying member is driven for a predetermined time.   The image forming apparatus according to claim 3, wherein the predetermined period is a time during which the stirring unit is driven for a predetermined time.   8. The time required to measure the remaining amount of developer in the fine detection mode is longer than the time required to measure the remaining amount of developer in the coarse detection mode. The image forming apparatus according to the item.   At least the image carrier, the developer carrier, the developer container, and the agitation unit are integrated into a process cartridge, and the process cartridge can be attached to and detached from the image forming apparatus main body. The image forming apparatus according to claim 1, wherein the image forming apparatus is an image forming apparatus.   The image forming apparatus according to claim 9, wherein the process cartridge includes a storage unit.   The image forming apparatus according to claim 10, wherein at least the number of image formations is stored in the storage unit.   12. The image forming apparatus according to claim 11, wherein the storage unit stores a planned number of image formations scheduled to be performed in the next precise detection mode.   The image forming apparatus according to claim 10, wherein at least a total number of rotations of the developer carrying member is stored in the storage unit.   The image forming apparatus according to claim 13, wherein the storage unit stores a predetermined rotation speed of the developer carrying member scheduled to be subjected to the next precise detection mode.   The image forming apparatus according to claim 10, wherein the storage unit stores at least a total number of rotations of the stirring unit.   The image forming apparatus according to claim 15, wherein the storage unit stores a predetermined number of rotations of the stirring unit that is scheduled to perform the next precise detection mode.   The image forming apparatus according to claim 9, wherein a plurality of the process cartridges containing developers of different colors are provided. A developer containing portion that contains a developer for developing a latent image formed on the image carrier, and an agitating means for changing the drive for stirring the developer in the developer containing portion; A plurality of remaining developer detectors, each having a plurality of developer remaining amount detecting devices having sensor means for detecting the remaining amount of the developer in the developer accommodating portion of each developing device; The remaining amount detection device is an image forming apparatus that detects the remaining amount of developer in each of the developing devices based on the detection value of each of the sensor units.
The developer remaining amount detecting device includes a rough detection mode for roughly detecting the remaining amount of the developer in the developer accommodating portion, and a precise detection for accurately detecting the remaining amount of the developer in the developer accommodating portion. With mode,
When the remaining amount of developer in any of the developing devices is detected in the rough detection mode, the remaining developer detecting device executes the precise detection mode in all the remaining developer detecting devices. The developer remaining amount detecting device determined to have the least amount of developer remaining in the developer container when the developer remaining amount detecting device continues in the rough detection mode for a predetermined period. An image forming apparatus.

Images