Patent Publication Number: US-7917078-B2

Title: Waste collection device and image forming apparatus

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application claims priority from Japanese Patent Application No. 2008-051248 filed Feb. 29 2008, Application No. 2008-051243 filed Feb. 29 2008, and Application No. 2008-051237 filed Feb. 29 2008. The entire content of these priority applications is incorporated herein by reference. 
     TECHNICAL FIELD 
     The present disclosure relates to a waste collecting device and an image forming apparatus. 
     BACKGROUND 
     An image forming apparatus such as a laser printer includes a toner carrier (e.g. a conveying belt) for conveying sheets, performing intermediate transfer, or the like. This toner carrier can have untransferred toner remaining clinging thereto. This residual toner can give an undesired influence to subsequent image forming operation. 
     There is a known image forming apparatus that includes a waste collecting device for collecting the waste clinging to the toner carrier. Furthermore, there is an image forming apparatus that further includes a waste detecting unit. The waste detecting unit detects an amount of the waste collected in the waste collecting device reaching a predetermined amount. With this waste detecting unit, overflow of the waste out of the waste collecting device is prevented from occurring. 
     Specifically, the known waste collecting device has a collection opening and a displaceable member. The collection opening allows the collected waste to enter, while the displaceable member is disposed directly below the collection opening. This displaceable member is displaced according to an amount of the waste accumulated and, by detecting this displacement, it is determined that the waste amount in the waste collecting device has reached the predetermined amount. 
     Moreover, there is another known waste collecting device that has a collection opening and a waste detecting sensor. The collection opening allows the collected waste to enter, while the waste detecting sensor is disposed near the collection opening. In this art, the waste accumulated directly below the collection opening is detected by the waste detecting sensor and, based on the detection results, it is determined whether or not the waste collecting device is filled with the waste. 
     SUMMARY 
     However, in any one of these known toner collecting devices, a zone or area directly below the collection opening is rendered or utilized as the waste detection zone for the waste detecting means. With this configuration, regardless of the amount of the waste collected in the waste collecting device, the waste collected through the collection opening always enters this detection zone and, therefore, the waste tends to be accumulated specifically in this detection zone, which can result in determination error that the waste has reached the predetermined amount (in spite that the amount of the waste collected in the toner collecting device is less). 
     Furthermore, the entire frame of any one of the known waste collecting devices is formed by welding or the like two members made of same material to each other. That is, it is not taken into consideration that material characteristics (intensity, quality of the material, and the like) to be required for each member are different. 
     An aspect of the present invention is a waste collecting device including a first box including a top surface having a first opening, a bottom surface opposed to the top surface, and side surfaces connecting the top surface and the bottom surface and having a second opening, wherein the top surface, the bottom surface, and the side surfaces define a space allowing waste to be accommodated therein; a second box including a top surface, a bottom surface opposed to the top surface, and side surfaces connecting the top surface and the bottom surface and having a third opening, the third opening being in communication with the second opening; and a sending unit disposed in the first box and configured to send the waste in a direction away from the second box. 
     Another aspect of the present invention is a waste collecting device including a first frame configured to support a removing member. The removing member can remove waste on a toner carrier. The waste collecting device also includes a second frame disposed adjacent to the first frame. The waste collection device also includes a third frame having a box shape with an entire top face thereof opened. The third frame can receive the waste removed by the removing member. The first frame and the second frame covers the opening of the third frame. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a side cross-sectional view showing a schematic configuration of a printer of an illustrative aspect in accordance with the present invention; 
         FIG. 2  is a block diagram showing an electrical structure of the printer; 
         FIG. 3  is a perspective view of a cleaning device as viewed from above; 
         FIG. 4  is a perspective view of the cleaning device as viewed from below; 
         FIG. 5  is an exploded view of a parts of the cleaning device; 
         FIG. 6  is a perspective view showing an internal structure of a third frame; 
         FIG. 7  is a top view showing the internal structure of the third frame; 
         FIG. 8  is a first cross-sectional view of the cleaning device taken along line X-X of  FIG. 4 ; 
         FIG. 9  is a second cross-sectional view of the cleaning device taken along the line X-X of  FIG. 4 ; 
         FIG. 10  is a third cross-sectional view of the cleaning device taken along the line X-X of  FIG. 4 ; 
         FIG. 11  is a fourth cross-sectional view of the cleaning device taken along the line X-X of  FIG. 4 ; 
         FIG. 12  is a cross-sectional view of the cleaning device taken along line Y-Y of  FIG. 4 ; and 
         FIG. 13  is a perspective view showing an internal structure of the third frame of another illustrative aspect. 
     
    
    
     DETAILED DESCRIPTION 
     An illustrative aspect in accordance with the present invention will be described with reference to  FIGS. 1 through 12 . 
     1. General Configuration of Printer 
       FIG. 1  is a side cross-sectional view showing a configuration of a printer  1  (an illustration of an image forming apparatus) of this illustrative aspect. Note hereinafter that the left direction in  FIG. 1  represents the front direction of the printer  1 . The front direction of the printer  1  is indicated as “F-direction” in each figure. The printer  1  is a color printer that can form color images using various colors of toner (for example, black (K), yellow (Y), magenta (M), and cyan (C), can be used). In a case of hereinafter distinguishing each component by color, “K”, “Y”, “M”, or “C” that indicates the color will be added to the end of the reference numeral of the component. 
     The printer  1  includes a body casing  2 . An openable cover  2 A is provided on the top face of the body casing  2 , while a sheet-feed tray  4  is provided in the bottom portion of the body casing  2 . Sheets  3  (each an illustration of a recording media, which can be paper, plastic, and the like) can be stacked in the sheet-feed tray  4 . A sheet-feed roller  5  is provided above the front end of the sheet-feed tray  4 . As this sheet-feed roller  5  rotates, the uppermost one of the stacked sheets  3  is sent out to a registration roller  6 . The registration roller  6  corrects skew travel of the sheet  3  and, thereafter, conveys the sheet  3  onto a belt unit  11  of an image forming portion  10 . 
     The image forming portion  10  includes the belt unit  11 , an exposing portion  18 , a process portion, a fixing portion  31 , and the like. 
     The belt unit  11  is configured by extending a looped belt  13  (an illustration of a toner carrier) between a front and a rear belt-support rollers  12 . The belt  13  is made of polycarbonate or the like. By rotationally driving the rear belt-support roller  12 , the belt  13  circulates in a clockwise direction in the figure, so that the sheet  3  on the belt  13  is backwardly conveyed. On the other hand, inside the loop of the belt  13 , a transfer roller  14  is provided in each position opposed to each photosensitive drum  28  of the process portion (described below) across the belt  13 . 
     a cleaning device  17  is provided under the belt unit  11 . The cleaning device  17  collects toner, sheet powder, discharge products, and the like that are clinging to an outer surface of the belt  13  (hereinafter referred to as “waste W”). The cleaning device  17  (an illustration of a waste collecting device) will be described below. 
     The exposing portion  18  includes LED units  18 K,  18 Y,  18 M, and  18 C (each an illustration of an exposing unit). The LED units  18 K,  18 Y,  18 M, and  18 C correspond to colors of black, yellow, magenta, and cyan, respectively. LED units  18 K,  18 Y,  18 M, and  18 C are supported on a bottom face of the cover  2 A by respective support members (not illustrated). LED units  18 K,  18 Y,  18 M, and  18 C have LED heads  19 K,  19 Y,  19 M, and  19 C, respectively, on bottom-end portions thereof. Each of the LED heads  19 K,  19 Y,  19 M, and  19 C is a plurality of light-emitting elements including LEDs arranged in line in the right-left direction. Light emission of the light-emitting elements is controlled based on an image data to be formed. Surfaces of the photosensitive drums  28  are irradiated with respective lights emitted from the light-emitting elements, and thus the surfaces are exposed. 
     A process portion  20  includes process cartridges  20 K,  20 Y,  20 M, and  20 C. Each of the process cartridges  20 K,  20 Y,  20 M, and  20 C corresponds to respective one of the above-described colors. The process cartridges  20 K,  20 Y,  20 M, and  20 C have respective cartridge frames  21  and developer cartridges  22 K,  22 Y,  22 M, and  22 C, respectively. Each of the developer cartridges  22 K,  22 Y,  22 M, and  22 C is detachably attached to respective one of the cartridge frames  21 . Upon open of the cover  2 A, the LED units  18 K,  18 Y,  18 M, and  18 C move out following the cover  2 A, and the process cartridges  20 K,  20 Y,  20 M and  20 C become detachable from, or attachable to, the body casing  2 . Note that, in this illustrative aspect, the above-described LED units  18 K,  18 Y,  18 M, and  18 C, the process cartridges  20 K,  20 Y,  20 M, and  20 C, and transfer rollers  14  configure separate image forming units. 
     Each of the developer cartridges  22 K,  22 Y,  22 M, and  22 C includes a toner storage  23  and, further, below the toner storage  23 , a supply roller  24 , a developer roller  25 , a layer-thickness regulating blade  26 , an agitator  27 , and the like. Each toner storage  23  stores toner, which is a developer of each color. The toner released from the toner storage  23  is supplied onto the developer roller  25  by rotation of the supply roller  24 , and is frictionally and positively charged between the supply roller  24  and the developer roller  25 . Then, as the developer roller  25  rotates, the toner supplied onto the developer roller  25  enters between the layer-thickness regulating blade  26  and the developer roller  25 , is further sufficiently frictionally charged there, and is carried on the developer roller  25  as a thin layer having an even thickness. 
     The photosensitive drums  28  (each an illustration of a photoreceptor) and chargers  29  (which can be of the scorotron type) are provided below the respective cartridge frames  21 . The surface of each photosensitive drum  28  is covered with a photosensitive layer having a positive charge property. At the time of an image forming process, the photosensitive drum  28  is rotationally driven and, along with this, the surface of the photosensitive drum  28  is uniformly and positively charged by the charger  29 . Then, the positively charged portion is exposed by high-speed light scanning. Thus, an electrostatic latent image, which corresponds to an image to be formed on the sheet  3 , is formed on the surface of each photosensitive drum  28 . 
     Next, by rotation of the developer roller  25 , the positively charged toner is carried on the developer roller  25 , faces the photosensitive drum  28 , contacts therewith, and is supplied to the electrostatic latent image formed on the surface of the photosensitive drum  28 . Thus, the electrostatic latent image on the photosensitive drum  28  is visualized, and a toner image supplied with toner only on the exposed portion thereof is carried on the surface of the photosensitive drum  28 . 
     Thereafter, as the sheet  3  conveyed by the belt  13  passes the transfer positions between the photosensitive drums  28  and the transfer rollers  14 , the toner images carried on the surfaces of the respective photosensitive drums  28  are transferred by negative transfer voltage onto the sheet  3  one by one. The sheet  3  that carries the transferred toner images is next conveyed to the fixing portion  31 . 
     The fixing portion includes a heat roller  31 A and a pressure roller  31 B. The heat roller  31 A has a heat source, while the pressure roller  31 B presses the sheet  3  toward the heat roller  31 A. The fixing portion  31  fuses the toner image transferred onto the sheet  3 . The sheet  3  (fused by the fixing portion  31 ) is upwardly conveyed and exits onto the top face of the cover  2 A. 
     2. Electrical Structure 
       FIG. 2  is a block diagram showing an electrical structure of the printer  1 . 
     The printer  1  is, as shown in the same figure, includes a CPU  40  (an illustration of a determination unit), a ROM  41 , a RAM  42 , an NVRAM (nonvolatile memory)  43 , and a network interface  44 . They are connected to the image forming portion  10 , a below-described waste detecting sensor  15  (an illustration of a waste detecting unit), a display  45 , a manipulation portion  46 , and the like. 
     The ROM  41  stores programs for executing each kind of operation of the printer  1  such as printing process and waste removing process. The CPU  40  reads out the programs from the ROM  41  and, according to the programs, performs controls of each portion, while storing results of the process in the RAM  42  or in the NVRAM  43 . The network interface  44  can be connected to an external computer and the like (not illustrated) via communication lines  47 , and thus mutual data correspondence can be performed. 
     3. Configuration of Cleaning Device 
       FIG. 3  is a perspective view of the cleaning device  17  as viewed from above.  FIG. 4  is a perspective view of the cleaning device  17  as viewed from below.  FIG. 5  is an exploded view of case  50  parts of the cleaning device  17 . Note that the internal structure of the cleaning device  17  is omitted in  FIG. 1  and  FIG. 5 , while the outer shape of the cleaning device  17  is simplified in  FIG. 1 . 
     As shown in  FIG. 1 , the cleaning device  17  includes the flat box-shaped case  50 . The case  50  is provided below the belt  13 . A collection opening  51  (an illustration of an first opening) is defined in the top face and in the front-end side of the case  50 . A cleaning roller  52  (an illustration of a removing member) is rotatably provided near this collection opening  51 . The cleaning roller  52  is, for example, a foamed silicon roller that is configured by coating a metal roller shaft with a roller body made of conductive foamed material. Note that a backup roller  56  is rotatably provided above the cleaning roller  52 . The backup roller  56  is made of conductive material such as metal. The backup roller and the cleaning roller  52  hold the belt  13  therebetween from above and beneath. 
     A scraping roller  53  is rotatably provided behind the cleaning roller  52  in a manner pressed onto the cleaning roller  52 . This scraping roller  53  is a metal roller made of hard material such as metal and the like. 
     Furthermore, a rubber blade  54  as a scraping member is provided under the scraping roller  53  in a cantilever manner. The rear-end portion of the blade  54  is adhered to a holder  55 , while the front-end portion, which is a free end, is pressed onto a bottom face of the scraping roller  53  by elastic force of a body of the blade  54 . 
     Waste removing process is executed, for example, after printing process. The waste removing process is executed as follows. While the belt  13  circulates in the clockwise direction in the figure, a driving force from a motor (not illustrated) rotationally drives the cleaning roller  52  in a direction opposing against the circulating direction of the belt  13 , i.e. in a clockwise direction, proximate the contacting face. At the same time with this, the scraping roller  53  is rotationally driven in the counter-clockwise direction in the figure. On the other hand, the backup roller  56  circulates in the clockwise direction in the figure along with the circulation of the belt  13 . 
     The roller shaft of the backup roller  56  is grounded. At a time of the waste removing process, negative bias is applied to the cleaning roller  52 , while a lower negative bias is applied to the scraping roller  53 . Thus, by bias attraction and by contact force of the cleaning roller  52 , waste W clinging to the belt  13  moves to the cleaning roller  52  near the position where the cleaning roller  52  is opposed to the backup roller  56 . Then, the waste W carried on the cleaning roller  52  moves to the hard scraping roller  53  by bias attraction. Thereafter, the waste W carried on the scraping roller  53  is removed by the scraping blade  54 . Finally, the scraped waste W falls in the case  50  via the collection opening  51 . Note that, of course, in order to remove negatively charged sheet powder, bias of the polarity opposite to the above-illustrated polarity will be applied to the cleaning roller  52  and the like. 
     (1) Case Structure of Cleaning Device 
     As shown in  FIG. 5 , the case  50  is configured by three members, i.e. a first frame  57 , a second frame  58 , and a third frame  59 . 
     The first frame  57  supports the above-described cleaning roller  52 , the scraping roller  53 , and the blade  54 . Specifically, the first frame  57  has a rectangular shape having a right-left width greater than a lateral width of the belt  31 . The collection opening  51  is defined by opening a portion substantially central in the front-back direction of the first frame  57 . This collection opening  51  has a rectangular shape extending in the right-left direction. A right-left width of the collection opening is equal to or greater than the right-left width of the belt  13 . Furthermore, a handle  64  is provided on the front-end portion of the first frame  57 . 
     Each of the cleaning roller  52 , the scraping roller  53 , and the blade  54  has a length equal to or greater than the right-left width of the belt  13 . The scraping roller  53  is disposed above the collection opening  51 . Note that, in practice, the cleaning roller  52  is designed so as to have the right-left width dimension greater than an estimated width of waste spilling from the developer cartridges  22 , while the belt  13  is designed so as to have the right-left width greater than the right-left width of the cleaning roller  52 . Gears  60 ,  61  are provided on respective end portions (for example, the left-end portions) of the cleaning rollers  52  and the scraping roller  53 . These gears  60 ,  61  are meshed with each other. Furthermore, the gear  61  is meshed with an input gear  62 . When the cleaning device  17  is attached in the body casing  2 , this input gear  62  is meshed with an output gear (not illustrated) provided on the body casing  2 . Then, the cleaning roller  52  and the scraping roller  53  are rotationally driven by rotationally driving the output gear. Note that the first frame  57  is provided with a gear cover  63 . As shown in  FIG. 3  and the like, the gear cover  63  covers the gears  60 ,  61 , and partially the input gear  62 , and thereby protects the gears  60 ,  61 , and the input gear  62 . Furthermore, bosses  65 ,  65  are formed in a protruding manner on the right and left ends of the first frame  57 . The bosses  65 ,  65  can be fitted in respective support portions (not illustrated) provided on the body casing  2 . 
     The second frame  58  is disposed behind the above first frame  57  and adjacent to the first frame  57 . The second frame  58  has a rectangular flat plate shape extending in the right-left direction as a whole. 
     The third frame  59  serves as a receptacle of the waste W collected by the cleaning roller  52 . The third frame  59  has a box shape with the entire top face thereof opened. The opened portion  59 A is covered with the first frame  57  and the second frame  58 . Furthermore, positioning bosses  66 ,  66  are formed in a protruding manner on rear-end portions of respective right and left faces of the third frame  59 . The positioning bosses  66 ,  66  can be fitted in support portions (not illustrated) provided on the body casing  2 . With the positioning bosses  66 ,  66 , the cleaning device  17  is positioned with respect to the body casing  2 . Note that the internal structure of each of the second frame  58  and the third frame  59  will be described below. 
     The first frame  57 , the second frame  58 , and the third frame  59  are secured to each other, for example, screwed in a state where the edge portions thereof are meshed with each other. For example, as shown in  FIG. 1  and in below-described  FIG. 8 , concavities and convexities provided along the edge portions of the second frame  58  are meshed with the concavities and convexities provided along the edge portions of the first frame  57  and the third frame  59 , and this second frame  58  is fastened to the third frame  59 , for example, with screws  70 ,  70 . 
     In this illustrative aspect, the first frame  57  is made of rigid material such as glass-fiber resin. This causes effects as follows. While the cleaning roller  52 , the scraping roller  53 , the blade  54 , and the gears  60  to  62  have certain weights, the first frame  57  can steadily support these cleaning roller  52  and the like. Furthermore, the first frame  57  can steadily press the cleaning roller  52  and the scraping roller  53  onto each other and, further, can uniformly contact the scraping roller  53  with the blade  54  over the entire width of the belt  13 . Therefore, higher collection performance for waste W can be obtained. Moreover, because the above-described positioning bosses  65 ,  65  are provided on the first frame  57  and near the rotational shafts of the cleaning roller  52  and the scraping roller  53 , tolerance in the positional relationship between the body casing  2 , the cleaning roller  52 , and the scraping roller  53  can be reduced in comparison with a case where the first frame  57  is made of soft material such as polystyrene resin (PS resin). 
     On the other hand, the second frame  58  and the third frame  59  are made of soft material such as PS resin. Thus, by forming only the first frame  57 , which specifically requires higher rigidity, out of glass-fiber resin that is comparatively more expensive, while forming the other frames (the second frame  58  and the third frame  59 ) out of PS resin that is comparatively cheaper, a total cost of the cleaning device can be reduced. 
     Furthermore, because the third frame  59  has a shape with the entire top face thereof opened, stripping process at a time of forming the third frame  59  is easier. 
     Suppose here that the first frame  57 , the second frame  58 , and the third frame  59  are assembled by welding. Then, attachment and position adjustment of the cleaning roller  52  and the like can be performed only after welding. To the contrary, in this illustrative aspect, the case  50  is configured by assembling the first frame  57 , the second frame  58 , and the third frame  59  by screwing, not by welding. Therefore, attachment and position adjustment of the cleaning roller  52  and the like to the first frame  57  can be performed before assembly. Furthermore, when taking away the waste W collected in the cleaning device  17 , it is only necessary to disengage only the second frame  58 . This makes it easier to take away the waste W. 
     In addition, The first frame  57 , the second frame  58 , and the third frame  59  are meshed with each other along the edge portions thereof. This serves in reducing spill of waste W from gaps between the first frame  57  and the second frame  58 , between the second frame  58  and the third frame  59 , and between the third frame  59  and the first frame  57 . 
     Furthermore, in this illustrative aspect, by opening the cover  2 A and detaching the process cartridges  20 K,  20 Y,  20 M, and  20 C and the belt unit  11 , the cleaning device  17  can be detached from the body casing  2 . Because the first frame  57  supports the cleaning roller  52  and the like, the first frame  57  can be heavier than the other frames  58 ,  59 . Therefore, in this illustrative aspect, the first frame  57  is provided with the handle  64 . By this, the center of gravity of the whole cleaning device  17  comes closer to the handle  64  and, therefore, the cleaning device is easy to carry. 
     Suppose that the handle  64  is provided in the side opposite to the collection opening  51  (the rear-end side of the cleaning device  17 ). Then, when grasping the handle  64  and lifting the cleaning device  17 , the collection opening  51  comes to a lower-end side of the cleaning device  17 , and the collected waste W can spill from the collection opening  51 . To the contrary, in this illustrative aspect, the handle  64  is provided on the collection opening  51  side. Therefore, when grasping the handle  64  and lifting the cleaning device  17 , the collection opening  51  is positioned at the upper-end side of the cleaning device  17 , and spill of the waste W from the collection opening  51  can be reduced. 
     (2) Internal Structure of Cleaning Device 
       FIG. 6  is a perspective view showing an internal structure of the third frame, while  FIG. 7  is a top view showing the internal structure of the third frame. Each of  FIGS. 8 through 11  is a cross-sectional view of the cleaning device  17  indicating a path of rotational movement of a below-described sending member  71 . In each of  FIGS. 8 through 11 , an outline arrow indicates the direction in which waste W is sent by the sending member  71 , while black bold arrows indicate a rotational direction of a crankshaft  75  of the sending member  71  and a movement direction of protrusions  77 , respectively. 
     The third frame  59  includes a waste-accommodating portion  72  for accommodating the waste W that has been collected by the cleaning roller  52  and has entered the collection opening  51 . This waste-accommodating portion  72  includes a first waste-accommodating portion  73  and a second waste-accommodating portion  74 . Note that, in the case  50 , a part corresponding to the first waste-accommodating portion  73  is a first box, while a part corresponding to the second waste-accommodating portion  74  is a second box. 
     The first waste-accommodating portion  73  is located directly below the above-described collection opening  51  and directly receives the waste W that has entered from the collection opening  51 . Specifically, as shown in  FIGS. 7 ,  8 , and the like, the first waste-accommodating portion  73  is a space expanding from a zone or area directly below the collection opening  51  to a rear wall of the third frame  59 . In addition, the first waste-accommodating portion  73  is upwardly stepped toward the rear wall. That is, a bottom face of the rear-end portion is higher by a step than the other portions thereof. 
     The first waste-accommodating portion  73  is provided with a sending unit. The sending unit sends the waste W, which has entered from the collection opening  51 , in a direction opposite to the second waste-accommodating portion  74  (the rear wall of the third frame  59 ). Specifically, this sending unit has the sending member  71 . The crankshaft  75  rotates a front-end portion of this sending member  71  in the collection opening  51  side, so that a rear-end portion of the sending member  71  reciprocates back and forth (see the black bold arrows in each of  FIGS. 8 through 11 ). As shown in  FIGS. 6 and 7 , the sending member  71  has a rectangular flat plate shape as a whole and a plurality of holes  71 A defined therethrough; the sending member  71  thus has a lattice-like structure. 
     The crankshaft  75  has a rotational axis substantially in parallel to the cleaning roller  52  and the like. The front-end portion of the sending member  71  can be rotated by the crankshaft  75 . A gear  76  is provided on the left-end portion of the crankshaft  75 . This gear  76  is meshed with the above-described input gear  62 . Two protrusions  77 ,  77  are provided on the rear-end portion of the sending member  71 . The protrusions  77 ,  77  are movable back and forth while being restricted in up-and-down movement by a guide portion  78  of the third frame  59  and a guide portion  79  of the second frame  58  (see  FIG. 5 ). 
     When the input gear  62  is rotationally driven, the crankshaft  75  rotates in a clockwise direction in  FIG. 8 . Then, the front-end portion of the sending member  71  moves around the crankshaft  75  and, following this, the protrusions  77  are guided by the guide portions  78 ,  79  so that the rear-end portion of the sending member  71  moves back and forth. Note that, in this illustrative aspect, the rear-end portion of the sending member  71  moves back and forth on a level higher than the level of the rotational center of the crankshaft  75 . 
     The waste W, which has fallen from the collection opening  51 , is accumulated directly below the collection opening  51  into heaps (see  FIG. 8 ). Then, when the upper portions of the heaped waste W contacts the sending member  71 , the waste W of the upper portions is moved backward by the sending member  71  (see  FIG. 9 ). Thereafter, when the amount of the waste W accumulated in the first waste-accommodating portion  73  accumulates more and a large amount of waste W is accumulated in the rear-end side of the first waste-accommodating portion  73 , then, the waste W comes to contact with the rear-end portion of the sending member  71  and begins to be sent toward the center of the first waste-accommodating portion  73  (see  FIGS. 10 and 11 ). Thus, the waste W can be uniformly accommodated in the entire first waste-accommodating portion  73 . 
     Note that, when the sending member  71  is located at the uppermost position (see  FIG. 10 ), there is a clearance between the second frame  58  that serves as a ceiling of the case  50 . This is in order to allow the sending member  71  to smoothly move even when the first waste-accommodating portion  73  is filled with the waste W and, at the same time, to prevent spill of waste W out of the case  50 . 
     On the other hand, after the amount of the waste W accommodated in the first waste-accommodating portion  73  reaches a predetermined amount, the second waste-accommodating portion  74  receives the waste W spilled from the first waste-accommodating portion  73 . Specifically, the second waste-accommodating portion  74  is located in front of the zone directly below the collection opening  51 , and is in communication with the first waste-accommodating portion  73  (see  FIGS. 6 and 12 ) This communication opening is a second opening and a third opening. The second waste-accommodating portion  74  includes an auger  80  and a detection portion  81 . The auger  80  and the detection portion  81  are disposed in the second waste-accommodating portion  74 . The waste W moved by the auger  80  is accommodated in the detection portion  81 . 
     The auger  80  has a rotational shaft and a spiral blade formed around the outer periphery of the rotational shaft. The rotational shaft has a rotational axis substantially in parallel to the cleaning roller  52  and the like. A gear  82  is provided on the left-end portion of the auger  80 . The gear  82  has a gear connection with the above-described input gear  62  via an idle gear. When the input gear  62  is rotationally driven, the auger  80  rotates and sends the waste W accumulated in the second waste-accommodating portion  74  toward the right (upwardly in  FIG. 7 ). 
     As shown in  FIG. 6 , a raised bottom portion  83  is formed below the right-end side of the auger  80 . The raised bottom portion  83  is raised by a step. The above-described detection portion  81  is opened to the raised bottom portion  83 . Thus, only the waste W sent by the auger  80  and raised up onto the raised bottom portion  83  is accommodated in the detection portion  81  (see  FIG. 11 ). 
     The detection portion  81  has a flat shape to the right and left. The detection portion  81  is made of light-transmissive material. The waste detecting sensor  15  is, for example, of a transmission type having a light-emitting portion and the light-receiving portion disposed in a manner opposed to each other across the detection portion  81 . When the amount of the waste W accommodated in the detection portion  81  becomes equal to or more than a predetermined amount, the waste detecting sensor  15  of transmission type is in a light-blocked state. The above-described CPU  40  determines based on a detection signal from the waste detecting sensor  15  whether or not the amount of the waste W accommodated in the detection portion  81  has reached the predetermined amount, i.e. a full or near-full state. 
     Provided between the first waste-accommodating portion  73  and the raised bottom portion  83  is a guard wall  84 . This guard wall  84  prevents the waste W in the first waste-accommodating portion  73  from directly entering the detection portion  81 . 
     With the above-described configuration, while the waste W that has entered the collection opening  51  is accommodated in the first waste-accommodating portion  73 , the waste W accommodated in this first waste-accommodating portion  73  is not rendered to detection performed by the waste detecting sensor  15 . On the other hand, the waste W that has entered from the first waste-accommodating portion  73  is accommodated in the second waste-accommodating portion  74 , and this waste W accommodated in the second waste-accommodating portion  74  is rendered to the detection performed by the waste detecting sensor  15 . Therefore, determination error that the amount of the accommodated waste W has reached the predetermined amount (in spite that the accommodated amount is less) can be reduced in comparison with a known waste collecting device having a detection zone directly below a collection opening  51 . 
     Furthermore, until the waste W is accumulated to a certain amount in the first waste-accommodating portion  73 , entrance of the waste W into the second waste-accommodating portion  74  can be reduced by the sending unit. Therefore, the determination error that the amount of the accommodated waste W has reached the predetermined amount (in spite that the accommodated amount is less) can be still more reliably reduced. 
     Furthermore, the waste W that has entered the collection opening  51  is accommodated in the waste-accommodating portion  72 . The accommodated waste W is further sent to the detection portion  81  by rotation of the auger  80 . The waste W accommodated in this detection portion  81  is rendered to the detection performed by the waste detecting sensor  15 . Here, even if a large amount of waste W is accumulated into heaps in a particular zone near the auger  80  (a zone indicated by a reference numeral Pin  FIG. 7 ), it is impossible for the waste W in this zone P to be directly rendered to the detection performed by the waste detecting sensor  15 . The auger  80  rotates and thereby moves (and evens), the waste W in the zone P and in other zones P′ along the rotational shaft direction. Then, the waste W finally moved into the detection portion  81  is rendered to the detection performed by the waste detecting sensor  15 . That is, regardless of difference in zones where the large amount of waste W is accumulated, the auger  80  moves the waste W accumulated in these zones in the direction of the rotational shaft. Thus, when the waste W is accumulated in the second waste-accommodating portion  74  to a predetermined height and substantially over the entire length of the auger  80 , the waste W begins to enter the detection portion  81  (see  FIG. 11 ). Consequently, variety in detection results depending on the difference in the zones where the large amount of waste W is accumulated can be reduced. 
     Suppose here that the handle  64  and the detection portion  81  are disposed in opposite sides in the case  50 . Then, when the handle  64  is grasped and the cleaning device  17  is inclined, the waste W in the first waste-accommodating portion  73  is caused to enter the detection portion  81 . Then, when the cleaning device  17  is settled again in the body casing  2 , determination error that the amount of the waste W accommodated in the cleaning device  17  has reached the predetermined amount (in spite that the accommodated amount is less) can be caused. To the contrary, in this illustrative aspect, the handle  64  and the detection portion  81  are provided in a same side in the case  50 . Therefore, such a problem as described above is difficult to be caused. 
     &lt;Other Illustrative Aspects&gt; 
     The present invention is not limited to the illustrative aspect as described above with reference to the drawings; for example, the following illustrative aspects are also included within the scope of the present invention. 
     (1) In the above-described illustrative aspect, the belt  13  for conveying sheets is adopted as the “toner carrier”. A main purpose of the belt  13  is to convey the sheets  3 . Density patches or registration marks for color shift detection are printed on the belt  13  at proper timings and, thereafter, these patches or registration marks are collected by the cleaning device  17 . The present invention is not limited to this; the belt may be an intermediate transfer belt or a photoreceptor belt with a main purpose is to carry toner images. 
     (2) In the above illustrative aspect, the second frame  58  is configured to be detachably attached by screws  70 . The present invention is not limited to this; the second frame  58  may be detachably attached by press fitting or with a lock mechanism. 
     (3) In the above-described illustrative aspect, the optical-type sensor is adopted as the “waste detecting unit”. The sensor may be other non-optical type sensors (e.g. a noncontact-type sensor, a contact-type sensor, or the like). 
     (4) In the above-described illustrative aspect, the sending member  71  is provided as the “sending unit”. The present invention is not limited to this. For example, the waste W may be sent by rotation of a rotatable member having an ellipsoidal cross-sectional shape and disposed in parallel to the cleaning roller  52  and the like. Or, it may simply be a bottom face of the waste-accommodating portion  72 , which is downwardly inclined toward the rear end thereof. Or, the sending unit may be excluded. In this case, it is preferable that the second waste-accommodating portion  74  is upwardly raised by a step with respect to the first waste-accommodating portion  73 . 
     (5) In the above-described illustrative aspect, the cleaning device  17  includes the cleaning mechanism such as the cleaning roller  52 , the scraping roller  53 , the blade  54 , and the like as the “waste collecting device”. The present invention is not limited to this; the cleaning mechanism, or parts thereof, may be excluded. 
     (6) In the above-described illustrative aspect, the collection opening  51  is elongated in the right-left direction, and the auger  80  is provided in parallel to the elongated direction of the collection opening  51 . The present invention is not limited to this; the auger  80  maybe provided nonparallel to the direction. Note however that, in the case where the collection opening  51  is elongated in the right-left direction, the waste W can be accumulated into heaps at various zones along the elongated direction of the collection opening  51 . Therefore, with the configuration of the above-described illustrative aspect, variation in detection results performed by the waste detecting unit due to the variation in the zones where the waste W is accumulated can be reduced. 
     (7) In the above-described illustrative aspect, the auger  80  is disposed in a front side of the third frame  59  (in the second waste-accommodating portion  74 ). The auger  80  may be disposed in, for example, a rear side of the third frame  59  (in the first waste-accommodating portion  73 ) as shown in  FIG. 13 . In this case, a raised bottom portion  91 , a guard wall  92 , and a detection portion  90  should be disposed in the front-end side of the third frame  59 . Note that they are configured similar to the above-described raised-bottom  83 , the guard wall  84 , and the detection portion  81 . The auger  80  sends out the waste W gathered in the rear-end side of the third frame  59  by the sending member  71  into the detection portion  90 . Even with such a configuration, the auger  80 , regardless of difference in the zones where the large amount of waste W is accumulated, sends out the waste W accumulated in these zones in the direction of the rotational shaft. Thus, when the waste W is accumulated in the first waste-accommodating portion  73  to the predetermined height and substantially over the entire length of the auger  80 , the waste W begins to enter the detection portion  90 . Therefore, variation in the detection results due to the difference in the zones where the large amount of waste W is accumulated can be reduced. In a short, it is only necessary for the waste collecting device to include a collection opening, a waste-accommodating portion that receives the waste that has removed from a toner carrier and has entered from the collection opening, an auger that rotates about a predetermined rotational shaft in the waste-accommodating portion and thereby sends out the waste accommodated in the waste-accommodating portion in a sending direction along the rotational shaft, and a detection portion that is provided on the distal-end side of the sending direction by the auger, accommodates the waste sent moved by the auger, and renders the accommodated waste to the detection performed by a waste detecting unit. 
     (8) In the above-described illustrative aspect, the cleaning device  17  is detachable from, and attachable to, the body casing  2 . The cleaning device  17  may be undetachable and attachable. 
     (9) In the above-described illustrative aspect, the printer  1  that exposes the photoreceptor using LEDs is illustrated. Other types of printers may be used, such as an electrophotographic image forming apparatus such as a laser printer that exposes the photoreceptor using laser light.