JP2008256864A - Residual toner amount detection system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a residual toner amount detection system configured to accurately detect a residual toner amount. <P>SOLUTION: Light emitted from a light emitting element is transmitted through a developing unit, and the light is varied in accordance with the residual toner amount. The output of a light receiving element of a toner detecting sensor is fetched in (SP1), the received light amount obtained when a developing part is moved to a positive side is discriminated (SP2 and SP3), the maximum received light amount is stored (SP4). The received light amount obtained when the developing part is moved to a negative side is discriminated (SP5 and SP6), the maximum received light amount is stored (SP7). The maximum value on the positive side is compared with the maximum value on the negative side, and the position located on the side having the larger received light amount is decided as a developing position (SP8). <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a toner remaining amount detection system that detects the remaining amount of toner in a developing device in a color image forming apparatus, for example.

In order to detect the remaining amount of toner in the developing device, the color image forming apparatus is provided with a remaining toner amount detecting device as described in, for example, Japanese Patent Laid-Open No. 2000-75749 (Patent Document 1). ing. This toner remaining amount detection device transmits light from a light emitting element of a toner detection sensor into a developing device, reflects the light by a reflecting plate such as a prism, and guides the light to a light receiving element of the toner detection sensor. Is received and converted into an electrical signal. The transmitted light becomes the intensity of the light depending on the remaining amount of toner, which is converted as the intensity of the electric signal, and the remaining amount of toner is reduced by comparing the electric signal with a preset threshold value. Detected.
JP 2000-75749 A (summary, FIG. 1)

  In a color image forming apparatus, for example, in a rotary developing device, development is performed so that a developing device that develops four colors rotates to obtain a predetermined color. When the toner remaining amount detecting device is attached to the rotary type developing device, the prism is attached to the rotating body of each developing device, and the toner detecting sensor including the light emitting element and the light receiving element is attached to a fixed developing position. When developing a predetermined color, it is necessary to stop an optical system such as a prism of a corresponding developing unit so as to be in a position facing the toner detection sensor. If the developing device stops at a position where the toner detection sensor and the optical system are displaced, the remaining amount of toner cannot be detected accurately.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a toner remaining amount detection system capable of accurately detecting the remaining amount of toner.

  The present invention is a toner remaining amount detection system in which a developing device in which toner is stored and a toner detection sensor for detecting toner are relatively movable, and the toner detection sensor is disposed in the developing device. A light emitting element that irradiates the light, and a light receiving element that detects the light that is emitted from the light emitting element through the developing device and changes depending on the remaining amount of toner, so that the amount of light received by the light receiving element is maximized And a positioning means for positioning a relative position between the developing unit and the toner detection sensor.

  Preferably, the positioning unit corrects the moving unit that moves the developing unit, and the position when the developing unit is moved by the moving unit and is made to be relative to the toner detection sensor so that the amount of light received by the light receiving element is maximized. Correction means.

  Preferably, the developing device is a color developing device, and one toner detection sensor is fixedly provided at a predetermined position, and a plurality of developing devices are provided corresponding to each of different colors. Each time a color is developed, it is positioned by a positioning means at a predetermined position so as to face the toner detection sensor.

  Preferably, the correction unit corrects the position where the output of the light receiving element is maximum when the developing unit is moved by the moving unit in at least one of the predetermined direction and the opposite direction to the predetermined direction. To do.

  According to the present invention, since the relative position between the developing device and the toner detection sensor is positioned so that the amount of light received by the light receiving element is maximized, the remaining amount of toner can be accurately detected.

  FIG. 1 is a diagram schematically showing an example of a color image forming apparatus 10 provided with a toner remaining amount detection system according to an embodiment of the present invention. In FIG. 1, the color image forming apparatus 10 includes a photosensitive drum 11, a laser scanning unit 12, a charging member 13, and a rotary developing device 14.

  The developing device 14 includes developing devices 14a to 14d corresponding to the respective colors. For example, the developing device 14 includes a black (BK) developing unit 14a, a magenta (M) developing unit 14b, a cyan (C) developing unit 14c, and a yellow (Y) developing unit 14d. Each color developing device 14 a to 14 d includes a developing container 15, a toner supply roller 16, and a developing roller 17.

  The developing device 14 is rotationally driven by a driving force applied from a driving unit (not shown) via a clutch, and sequentially develops toner images on the photosensitive drum 11 by the developing rollers 17 of the developing devices 14a to 14d of the respective colors. Form. Around the photosensitive drum 11, a cleaning rubbing member 18 and a cleaning device 19 are disposed. An intermediate transfer belt 20 is disposed in contact with the photosensitive drum 11, and the intermediate transfer belt 20 is interposed therebetween. The photosensitive drum 11 and the primary transfer roller 21 face each other.

  The intermediate transfer belt 20 is stretched between the primary transfer roller 21, the drive roller 22, and the driven roller 23, and the intermediate transfer belt 20 is rotationally driven in the direction of the arrow. Further, a secondary transfer roller 24 is provided to face the driving roller 22 with the intermediate transfer belt 20 interposed therebetween. The toner image on the photosensitive drum 11 is primarily transferred onto the intermediate transfer belt 20 by the primary transfer roller 21. The recording paper is conveyed from the paper feed cassette 25 through the paper feed path 26 to a secondary transfer position that is a nip portion between the drive roller 22 and the secondary transfer roller 24, and is transferred onto the intermediate transfer belt 20 at the secondary transfer position. The toner image is secondarily transferred to the paper. Thereafter, the recording sheet is conveyed to the fixing unit 27 where the toner image on the sheet is fixed, and the sheet is discharged to the discharge tray 29 through the discharge path 28.

  The toner layer on the developing roller 17 is regulated in thickness by a layer thickness regulating member (not shown) and is frictionally charged, and the electrostatic latent image on the photosensitive drum 11 is developed by the developing roller 17.

  When replenishing toner to the developing device 14a, the developing device 14 is rotationally driven to position the developing device 14a at a toner replenishing position in the vicinity of the replenishing pipe 33 shown in FIG. Then, the tip of the supply pipe 33 is inserted into a connecting portion (not shown) of the developing device 14a, so that the toner is supplied to the toner chamber.

  FIG. 2 is an external perspective view of the developing unit shown in FIG. 1, and FIG. 3 is a diagram showing the configuration of the toner detection sensor, the optical path, and the reflecting mirror.

  As shown in FIG. 2, the developing unit 14a is provided with a side wall 14f, and the toner detection sensor 43 is fixedly provided at a predetermined position with a certain interval facing the side wall 14f. As shown in FIG. 3, the toner detection sensor 43 includes a light emitting element 44 and a light receiving element 45. In the developing device 14a, an optical path 46, a reflecting mirror 48, an optical path 47, and a reflecting mirror 49 are provided in the vicinity of the side wall 14f. The optical path 46, the reflecting mirror 48, the optical path 47, and the reflecting mirror 49 operate as an optical system.

  The optical path 46 is provided so that one end is exposed from the side wall 14f and faces the light emitting element 44 and extends in the first direction in the toner chamber 15a. The optical path 47 is provided in the toner chamber 15 a so that one end is exposed from the side wall 14 f and faces the light receiving element 45 and extends in parallel to the optical path 46. Reflecting mirrors 48 and 49 are provided at the other ends of the optical paths 46 and 47, respectively, so that the optical axes formed by each of them intersect with each other in the first direction of the toner chamber 15a. Instead of the reflecting mirrors 48 and 49, prisms or other reflecting means may be used.

  The light emitted from the light emitting element 44 enters from the end face of the optical path 46, is reflected from the reflecting mirror 48, passes through the toner in the toner chamber 15a, and enters the light receiving element 45 from the reflecting mirror 49 via the optical path 47. The If the remaining amount of toner in the toner chamber 15a is large, the amount of light incident on the reflecting mirror 49 from the reflecting mirror 48 becomes small. If the remaining amount of toner decreases, the amount of light incident on the reflecting mirror 49 from the reflecting mirror 48 increases. Therefore, the remaining amount of toner can be detected by the light receiving output of the light receiving element 45.

  Similarly, the other developing units 14b to 14d are provided with optical paths 46 and 47 and reflecting mirrors 48 and 49, respectively. In the toner detection sensor 43, when the developing device 14 rotates and any one of the developing devices 14a to 14d is in a home position which is a developing position, the light emitting element 44 and the light receiving element 45 are in an optical path 46 of the developing device. When the optical axes coincide with each other so as to face the optical path 47, the remaining amount of toner in the corresponding developing device is detected. Thus, without providing the toner detection sensor 43 in each of the developing devices 14a to 14d, the toner of the four developing devices 14a to 14d is obtained by one toner detection sensor 43 each time the developing devices 14a to 14d rotate. The remaining amount can be detected.

  FIG. 4 is a block diagram of a toner remaining amount detection system according to an embodiment of the present invention. 4, the toner remaining amount detection system includes a light emitting element control unit 51, a toner detection sensor 43 including a light emitting element 44 and a light receiving element 45, a light receiving element control unit that operates as a toner presence / absence determining unit, a positioning unit, and a correcting unit. 52, a storage unit 53, and a drive unit 54 that operates as a moving means. The light emitting element control unit 51 and the light receiving element control unit 52 are included in a control unit (not shown) that controls the color image forming apparatus 10.

  The light emitting element control unit 51 performs control for lighting the light emitting element 44, and intermittently turns on and off the light emitting element 44 by, for example, pulse width modulation. The light receiving element control unit 52 receives the light receiving output of the light receiving element 45, determines the level of the light receiving output, and determines the presence or absence of toner.

  In addition, the light receiving element control unit 52 positions the relative positions of the developing units 14 a to 14 d and the toner detection sensor 43 so that the amount of light received by the light receiving element 45 is maximized based on the light reception output of the light receiving element 45. For this purpose, the light reception output of the light receiving element 45 is stored in the storage unit 53 and the drive unit 54 that operates as a moving unit is controlled. The driving unit 54 sequentially rotates so that each of the developing devices 14a to 14d is located at a predetermined developing position.

  FIG. 5 is a flowchart for explaining the operation at the time of initial adjustment of the toner remaining amount detection system according to the embodiment of the present invention.

  For example, in a state in which the developing device 14a containing no toner is incorporated in the color image forming apparatus 10, the developing device 14a is moved to a default position which is a predetermined position. The light emitting element control unit 51 turns on the light emitting element 44. When the light emitting element 44 is lit, the lit light is guided to the light receiving element 45 via the optical path 46, the reflecting mirror 48, the optical path 47, and the reflecting mirror 49 of the developing device 14a as shown in FIG. The light receiving element 45 receives the light. The light reception output of the light receiving element 45 is given to the light receiving element control unit 52.

  In step (abbreviated as SP in the drawing) SP1, the light receiving element control unit 52 takes in the light reception output of the light receiving element 45 and measures the transmittance between the optical paths 46 and 47 and the reflecting mirrors 48 and 49. Based on the light reception output of the light receiving element 45, the position where the transmittance is maximized is set as the developing position of the home position of the developing device 14a.

  That is, in step SP2, the driving unit 54 moves the developing device 14a from the default position to the + side as a predetermined direction. Here, the + side indicates, for example, a clockwise direction in which the developing devices 14a to 14d of the rotary type developing device 14 shown in FIG. 1 are rotated in order to switch, and the − side indicates a counterclockwise direction opposite thereto. To do. In step SP3, it is determined whether or not the amount of light received by the light receiving element 45 has increased. If it has increased, in step SP2, the developing device 14a is further moved slightly to the + side. In step SP3, it is determined whether or not the amount of received light has increased. This operation is repeated, and the position where the amount of received light is maximized when the developing device 14a is moved to the + side in FIG. 1, for example, is obtained. If it is determined in step SP3 that the amount of received light does not increase any more, the output of the light receiving element 45 at that time is stored in the storage unit 53 in step SP4.

  In step SP5, the developing device 14a is moved in the negative direction from the default position. In step SP6, it is determined whether or not the amount of received light has increased. If it has increased, the process returns to step SP5 to move the developing device 14a slightly to the negative side. In step SP6 again, it is determined whether or not the amount of received light has increased. This operation is repeated to obtain a position where the amount of received light becomes maximum when the developing device 14a is moved to the negative side. If it is determined in step SP6 that the amount of received light is no longer increased, it is determined that the amount of received light is maximized, and the output of the light receiving element 45 at that time is stored in the storage unit 53 in step SP7. In step SP8, the maximum value of the light receiving output on the + side of the light receiving element 45 stored in the storage unit 53 is compared with the maximum value of the light receiving output on the-side, and the position where the light receiving output is larger is the home of the developing device 14a. Determine as the position of the position.

  Note that when the developing device 14a is moved from the default position to at least one of the + side and the − side, the position where the output of the light receiving element 45 reaches the peak may be corrected to be the developing position. That is, for example, if the light reception output increases when moved to the + side, the peak value of the light reception output exists on the + side, and therefore detection on the-side may be omitted. On the contrary, when the amount of received light is small, the peak value of the received light output is on the − side, and therefore the detection time can be shortened if the detection on the + side is omitted.

As described above, according to this embodiment, the position at which the output of the light receiving element 45 is maximized when the developing device 14a is moved in the + direction and the − direction by the driving unit 54 is corrected so as to become the developing position. Can do. As a result, the toner detection sensor 43 and the optical paths 46 and 47 of the developing device 14a can be accurately opposed to each other, and the respective optical axes are not shifted, so that the presence or absence of the remaining amount of toner can be accurately detected. When the developing units 14b to 14d are moved to the development position, the same control is performed, so that the toner detection sensor 43 can accurately detect the remaining amount of toner at each position.

  In the above description, the case where the present invention is applied to the color image forming apparatus having the rotary developing device 14 has been described. However, the present invention may be applied to a color image forming apparatus having a tandem developing device.

  Further, a color copying machine, a color printer, or the like can be applied as the color image forming apparatus.

  As mentioned above, although embodiment of this invention was described with reference to drawings, this invention is not limited to the thing of embodiment shown in figure. Various modifications and variations can be made to the illustrated embodiment within the same range or equivalent range as the present invention.

1 is a diagram schematically illustrating an example of a color image forming apparatus including a toner remaining amount detecting device according to an embodiment of the present invention. FIG. 2 is an external perspective view of the developing device illustrated in FIG. 1. It is a figure which shows the structure of a toner detection sensor, an optical path, and a reflective mirror. 1 is a block diagram of a toner remaining amount detection system according to an embodiment of the present invention. FIG. 6 is a flowchart for explaining the operation of the remaining toner amount detection system according to the embodiment of the present invention.

Explanation of symbols

  10 color image forming measures, 14 rotary developing device, 14a to 14d developing device, 15a toner chamber, 43 toner detection sensor, 44 light emitting element, 45 light receiving element, 46, 47 optical path, 48, 49 reflecting mirror, 51 light emitting element control Part, 52 light receiving element control part, 53 memory | storage part, 54 drive part.

Claims (4)

A toner remaining amount detection system in which a developing device in which toner is stored and a toner detection sensor for detecting toner are relatively movable,
The toner detection sensor includes: a light emitting element that emits light into the developing unit; and a light receiving element that detects light that is irradiated from the light emitting element through the developing unit and changes according to the remaining amount of toner. And a positioning means for positioning a relative position between the developing device and the toner detection sensor so that the amount of light received by the light receiving element is maximized. The positioning means includes
Moving means for moving the developing device;
2. The correction unit according to claim 1, wherein a position when the developing unit is moved by the moving unit and is moved relative to the toner detection sensor includes a correction unit that corrects the received light amount of the light receiving element to be maximum. Toner level detection system. The developing device is a color developing device,
One toner detection sensor is fixed at a predetermined position, and one toner detection sensor is provided.
The developing device is provided in a plurality corresponding to each of different colors, and is positioned by the positioning means at the predetermined position so as to face the toner detection sensor every time the different colors are developed. The toner remaining amount detection system according to 1 or 2.   The correcting means sets the position where the output of the light receiving element is maximum when the developing unit is moved by the moving means in at least one of a predetermined direction and the opposite direction to the predetermined position. The toner remaining amount detection system according to claim 2 or 3, wherein

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