Image forming apparatus

Abstract

To provide an image forming apparatus capable of preventing the reversal of a cleaning blade with simple constitution.SOLUTION: An image forming apparatus 10 includes a photoreceptor 13 and a cleaning device 14 for removing residual toner on the photoreceptor 13. The cleaning device 14 includes a frame 41, a cleaning blade 42 that is provided in the frame 41, extends in a longitudinal direction of the photoreceptor 13, and abuts on the photoreceptor 13, and a metal plate 43 that is fixed to the frame 41 and holds the cleaning blade 42, and the cleaning device 14 includes a lubricant 45 that abuts on the photoreceptor 13 upstream of the cleaning blade 42, and the lubricant 45 is fixed to a tip of an elastic member 44a fixed to the cleaning device 14.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to an image forming apparatus. [Background technology]

[0002] Some image forming apparatuses use a charging roller. In this type of image forming apparatus, the surface properties of the photosensitive drum (hereinafter referred to as "photosensitive body") change, increasing the coefficient of friction μ, which can easily cause the cleaning blade in contact with the photosensitive body to turn over. To address this issue, Japanese Patent Laid-Open Publication No. 2010-091852 (Patent Document 1), for example, discloses a method in which a brush roller with a lubricant is brought into contact with the photosensitive body upstream of the cleaning blade in the rotation direction of the photosensitive body of the image forming apparatus, and the lubricant is applied to the photosensitive body via the brush roller. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-091852 Summary of the Invention [Problem to be solved by the invention]

[0004] In conventional image forming apparatuses, the cleaning blade has been prevented from reversing as described above. However, the configuration shown in Patent Document 1 has the problem that the configuration of the cleaning blade becomes complicated.

[0005] The present disclosure has been made to solve the above-mentioned problems, and has an object to provide an image forming apparatus that can prevent the cleaning blade from reversing with a simple configuration. [Means for solving the problem]

[0006] The image forming apparatus according to the present disclosure includes a photoconductor and a cleaning device that removes residual toner from the photoconductor. The cleaning device includes a frame, a cleaning blade that is provided within the frame and extends in the longitudinal direction of the photoconductor and contacts the photoconductor, and a cleaning blade holder that is fixed to the frame and holds the cleaning blade. The cleaning device includes a lubricant that contacts the photoconductor upstream of the position where the cleaning blade contacts the photoconductor in the rotation direction of the photoconductor, and the lubricant is fixed to a tip of an elastic member that is fixed to the cleaning device.

[0007] The lubricant may be fixed to the tip of the elastic member fixed to the frame, or may be fixed to the tip of the elastic member fixed to the cleaning blade holding portion.

[0008] It is preferable that the lubricant be in contact only with the photosensitive member outside the development region at both ends in the longitudinal direction.

[0009] The lubricant may be a solid made by compacting powdered stearic acid. [Effects of the Invention]

[0010] According to the present disclosure, the lubricant is fixed to the tip of the elastic member fixed to the cleaning device, so that the lubricant is always in contact with the photosensitive member, thereby providing a friction-reducing effect over a long period of time.

[0011] As a result, an image forming apparatus can be provided that can prevent the cleaning blade from reversing with a simple configuration.

[0012] The above and other objects, features, and advantages of the present disclosure will become more apparent from the following detailed description of the embodiments, which proceeds with reference to the drawings. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a schematic side view of an image forming apparatus according to an embodiment of the present disclosure. [Figure 2]2 is a view of a photosensitive member of an image forming apparatus, a photosensitive member cleaning device, and its periphery as viewed from the axial direction of the photosensitive member; [Figure 3] 1 is a perspective view of a photosensitive member and a cleaning device for the photosensitive member and its surroundings in an image forming apparatus according to an embodiment of the present disclosure. [Figure 4] 1 is a view of a photoconductor of an image forming apparatus according to an embodiment of the present disclosure, viewed from its longitudinal direction; [Figure 5] FIG. 10 is a perspective view showing another configuration for attaching a lubricant to an elastic member. [Figure 6] 10A and 10B are diagrams illustrating an initial state when an elastic member with a lubricant attached thereto is brought into contact with a photosensitive member. [Figure 7] 10A and 10B are diagrams illustrating a state after a certain time has elapsed when an elastic member with a lubricant attached thereto is brought into contact with a photosensitive member. [Figure 8] 10A and 10B are diagrams illustrating an initial state when an elastic member having a lubricant of a different shape is brought into contact with a photosensitive member. [Figure 9] 10A and 10B are diagrams illustrating a state after a certain time has elapsed when an elastic member having a different shape of lubricant attached thereto is brought into contact with a photosensitive member. [Figure 10] 10 is a view showing an initial state when an elastic member having a lubricant of another shape attached thereto is brought into contact with the photosensitive member as viewed from the axial direction of the photosensitive member; FIG. [Figure 11] 10 is a view showing an initial state when an elastic member having a lubricant of another shape attached thereto is brought into contact with the photosensitive member as viewed from the axial direction of the photosensitive member; FIG. [Figure 12] 10A and 10B are diagrams illustrating a state in which an elastic member with a lubricant attached thereto is brought into contact with a photosensitive member in a second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0014] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present disclosure will now be described in detail with reference to the accompanying drawings. Fig. 1 is a schematic side view of an image forming apparatus according to an embodiment of the present disclosure.

[0015] The image forming apparatus 10 of the present disclosure is configured to include an exposure device 11, a developing device 12, a photosensitive member 13 (an example of an image carrier), a cleaning device 14, a charger 15, an intermediate transfer belt device 16, a fixing device 17, a paper feed tray 18, a paper discharge tray 19, and a paper transport path S, and forms multi-color and monochrome images on a specified paper sheet according to image data transmitted from outside.

[0016] The image data handled by the image forming apparatus 10 corresponds to a color image using the colors black (K), cyan (C), magenta (M), and yellow (Y). Therefore, four developing devices 12, four photoconductors 13, four chargers 15, and four cleaning devices 14 are provided to form four types of latent images corresponding to each color, and are set to black, cyan, magenta, and yellow, respectively, and these constitute four image stations Pa, Pb, Pc, and Pd.

[0017] The photoconductor 13 is disposed approximately in the vertical center of the image forming apparatus 10. The charger 15 uniformly charges the surface of the photoconductor 13 to a predetermined potential. The exposure device 11 exposes the surface of the photoconductor 13 to light to form an electrostatic latent image. The development device 12 develops the electrostatic latent image on the surface of the photoconductor 13 to form a toner image on the surface of the photoconductor 13. Through the series of operations described above, a toner image of each color is formed on the surface of each photoconductor 13. The cleaning device 14 removes and collects residual toner from the surface of the photoconductor 13 after development and image transfer.

[0018] The intermediate transfer belt device 16 is disposed above the photoreceptor 13 and includes an intermediate transfer belt 21, an intermediate transfer belt drive roller 22, an intermediate transfer belt driven roller 23, an intermediate transfer roller 24, and an intermediate transfer belt cleaning device 25. Four intermediate transfer rollers 24 are provided, one for each of the image stations for YMCK colors.

[0019] The intermediate transfer belt drive roller 22, the intermediate transfer belt driven roller 23, and the intermediate transfer roller 24 are configured to stretch the intermediate transfer belt 21 and move the surface of the intermediate transfer belt 21 in a predetermined direction (the direction of the arrow C in the figure).

[0020] The paper transport path S includes a main path S1 formed in an S-shape and a reversing path S2 that branches off from the main path S1 midway and then rejoins the two paths, and along the main path S1, a pickup roller 31, pre-registration rollers 33, registration rollers 32, secondary transfer device 26, fixing device 17, and paper discharge rollers 34 are arranged. The reversing path S2 branches off between the fixing device 17 and paper discharge rollers 34, passes through a plurality of transport rollers 35, and rejoins between the pre-registration rollers 33 and registration rollers 32. The secondary transfer device 26 includes a transfer roller 26a.

[0021] Furthermore, when forming an image on the back side of the paper as well as the front side, the paper is transported in the reverse direction from the paper discharge rollers 34 to the reversal path S2, the paper is turned over, the paper is guided again to the registration rollers 32, an image is formed on the back side in the same manner as on the front side, and the paper is then transported to the paper discharge tray 19. Next, we will explain the periphery of the photoreceptor 13 and the photoreceptor cleaning device 14 of the image forming apparatus 10. Fig. 2 is a diagram of the periphery of the photoreceptor 13 and the photoreceptor cleaning device 14 of the image forming apparatus 10 shown in Fig. 1 as viewed from the axial direction of the photoreceptor 13, and Fig. 3 is a perspective view of the periphery of the photoreceptor 13 and the photoreceptor cleaning device 14.

[0022] [First embodiment] 2 and 3, image forming apparatus 10 includes photoreceptor 13 and cleaning device 14 that removes residual toner from photoreceptor 13. Photoreceptor 13 rotates in the direction indicated by the arrow in FIG. 1. Cleaning device 14 includes frame 41, cleaning blade 42 that is provided within frame 41, extends in the longitudinal direction (axial direction) of photoreceptor 13, and abuts against photoreceptor 13, and a metal plate (cleaning blade holder) 43 that is fixed to frame 41 and holds cleaning blade 42. Cleaning device 14 includes lubricant 45a that abuts against photoreceptor 13 upstream of the position where cleaning blade 42 abuts against photoreceptor 13 in the rotation direction of photoreceptor 13. Lubricant 45a is a solid made by solidifying powdered stearic acid and is fixed to the tip of a film 44a made of PET (hereinafter referred to as "elastic member") that is fixed to cleaning device 14.

[0023] Here, the lubricant 45a has a surface that follows the circumferential surface of the photoreceptor 13 and is rectangular when viewed from the axial direction of the photoreceptor 13. A metal plate 43 is provided at the bottom of the frame 41 of the cleaning device 14, and the lubricant 45a is fixed to the tip of an elastic member 44a that is fixed to the metal plate 43.

[0024] As shown in FIG. 2, the metal plate 43 has a surface on the photoreceptor 13 side and an opposite surface, and the cleaning blade 42 is attached to the surface on the photoreceptor 13 side, and the elastic member 44a is attached to the opposite surface.

[0025] In FIG. 3, the elastic member 44a provided on the metal plate 43 and the lubricant 45a attached thereto are omitted.

[0026] Here, the structure for attaching lubricant 45a to elastic member 44a will be described. In the structure shown in Fig. 2, elastic member 44a having lubricant 45a attached to the tip thereof is held by metal plate 43, and elastic member 44a is attached to metal plate 43 while curved toward photoreceptor 13 so that lubricant 45a is pressed against photoreceptor 13.

[0027] Next, the longitudinal direction of the photoreceptor 13 will be described. Fig. 4 is a view of the photoreceptor 13 of the image forming apparatus 10 according to an embodiment of the present disclosure, viewed from a direction perpendicular to the rotation axis. Referring to Fig. 4, the central portion of the photoreceptor 13 in the longitudinal direction is the development area 46, which is covered by the charging area 47, and the cleaning area 48 is provided to cover the charging area 47.

[0028] Here, charging occurs in the charging region 47 of the photoreceptor 13, causing the surface of the photoreceptor 13 to become rough. At this time, a toner image is formed in the developing region 46 within the charging region 47, and the toner remaining after the toner image is transferred reaches the cleaning blade 42 (see FIGS. 2 and 3), where the toner acts as a lubricant and reduces the coefficient of friction μ between the photoreceptor 13 and the cleaning blade 42. On the other hand, since there is no toner in the charging region 47 but outside the developing region 46, the coefficient of friction μ at the contact point between the photoreceptor 13 and the cleaning blade 42 increases, forming a region 49 where the coefficient of friction μ increases. Therefore, in this embodiment, only in the region 49 where the coefficient of friction μ increases, which is in the charging region 47 but outside the developing region 46, a lubricant 45a provided at the tip of the elastic member 44a (see FIG. 2) is brought into contact with the photoreceptor 13 to reduce the coefficient of friction μ. In addition, in Figure 4, only the lubricant 45a provided in the region 49 where the friction coefficient μ increases outside the development region 46 within the charging region 47 at both ends of the photosensitive member 13 in the longitudinal direction is shown, and the elastic member 44a is not shown.

[0029] Next, a configuration for attaching a lubricant to an elastic member, which is different from the configuration for attaching lubricant 45a to elastic member 44a shown in Fig. 2, will be described. Fig. 5 is a perspective view showing another configuration for attaching a lubricant to an elastic member. Referring to Fig. 5, elastic member 44b here is not curved so as to be pressed against photoreceptor 13 like elastic member 44a described above, but is a flat plate attached parallel to cleaning blade 42 (see Figs. 2 and 3), and equilateral triangular lubricant 45b is attached to one end of elastic member 44b so as to share one side with elastic member 44b.

[0030] Next, the change over time of the lubricant 45b will be described. Fig. 6 is a diagram showing the initial state when the elastic member 44b with the lubricant 45b attached thereto is brought into contact with the photosensitive member 13, and Fig. 7 is a diagram showing the state after a certain time has elapsed when the elastic member 44b with the lubricant 45b attached thereto is brought into contact with the photosensitive member 13.

[0031] The more times the photosensitive member 13 is charged, the greater the friction coefficient μ of the surface of the photosensitive member 13. Therefore, in this case, the contact area between the photosensitive member 13 and the lubricant 45b is made small in the initial state, and the contact area is made larger after a certain period of time has passed. 6 and 7, in the initial state when the elastic member 44b with the lubricant 45b attached thereto is brought into contact with the photosensitive member 13, the elasticity of the elastic member 44b causes the cleaning blade 42 and the vertices of the equilateral triangular lubricant 45b to come into contact with the photosensitive member 13. On the other hand, after a certain time has passed, the contact surface between the photosensitive member 13 of the cleaning blade 42 and the equilateral triangular lubricant 45b increases.

[0032] Next, other shapes of lubricant 45 will be described. The shape of the lubricant attached to the tip of the elastic member may be a right triangle with a right angle between its long and short sides, with the long side sharing the elastic member. Fig. 8 is a diagram showing the initial state in which elastic member 44b with lubricant 45c attached thereto is brought into contact with photoreceptor 13, and Fig. 9 is a diagram showing the state after a certain time has elapsed in this case, and corresponds to Figs. 6 and 7 when lubricant 45 is an equilateral triangle.

[0033] In the case of a right triangle with a right angle between its long and short sides, in the initial state when elastic member 44b with lubricant 45c attached is brought into contact with photosensitive member 13, the elasticity of elastic member 44b causes cleaning blade 42 and the vertices of right-angled triangular lubricant 45c to come into contact with photosensitive member 13. On the other hand, after a certain time has passed, the contact area between photosensitive member 13 of cleaning blade 42 and right-angled triangular lubricant 45c increases.

[0034] Next, another configuration different from the contact method of the elastic member and lubricant with the photoreceptor 13 shown in Figures 2, 5, etc. will be described. Figure 10 is a view seen from the axial direction of the photoreceptor 13 of an initial state when an elastic member 44c of another shape, to which the rectangular lubricant 45a shown in Figure 2 is attached, is contacted with the photoreceptor 13. Referring to Figure 10, here, the shape of the lubricant 45a attached to the tip of the elastic member 44c attached to the metal plate 43a is rectangular, similar to that in Figure 2, but the shapes of the metal plate 43a and the elastic member 44c are different, the degree of contact with the photoreceptor 13 is stronger than in Figure 2, and the elastic member 44c is curved more greatly when contacting the photoreceptor 13.

[0035] Next, another configuration will be described. Fig. 11 is a view seen from the axial direction of photoreceptor 13 showing a case in which elastic member 44c, to which lubricant 45c of the shape shown in Fig. 8 is attached, is brought into contact with photoreceptor 13. Referring to Fig. 11, lubricant 45c is fixed to the tip of elastic member 44c, which is fixed to metal plate 43a of the same shape as shown in Fig. 10. Lubricant 45c has a right-angled triangular shape, similar to Figs. 8 and 9, but the degree to which elastic member 44c is brought into contact with photoreceptor 13 is stronger than in Figs. 8 and 9, and elastic member 44c is curved more greatly when it comes into contact with photoreceptor 13.

[0036] Furthermore, the shape of the contact surface of the lubricant 45c against the photosensitive member 13 has a larger area as it approaches the mounting surface of the elastic member 44c.

[0037] As shown in Figures 10 and 11, by attaching the elastic member 44c that fixes the lubricants 45a and 45c and the cleaning blade 42 so that they are at an angle to each other, the distance between them can be made smaller as one approaches the tip of the cleaning blade 42, so that the lubricants 45a and 45c can be used up to the fixed position of the elastic member 44c.

[0038] [Second embodiment] Next, a second embodiment of the present disclosure will be described. Fig. 12 is a diagram showing a state in which a lubricant 50 attached to an elastic member 44 is brought into contact with the photoreceptor 13 upstream in the rotation direction of the photoreceptor 13 in the second embodiment of the present disclosure.

[0039] Referring to Figure 12, in the second embodiment, the cleaning device 14 also has a frame 41, a cleaning blade 42 that is provided within the frame 41, extends in the longitudinal direction of the photosensitive member 13 and abuts against the photosensitive member 13, and a metal plate 43 that is fixed to the frame 41 and holds the cleaning blade 42.

[0040] In the second embodiment, the cleaning device 14 also has a lubricant 50 that contacts the photoreceptor 13 upstream of the cleaning blade 42, but the lubricant 50 is fixed to the tip of an elastic member 44d that is fixed to the upper part of the frame 41 of the cleaning device 14 and extends downward. Here, the lubricant 50 has a surface that follows the circumferential surface of the photoreceptor 13, and has a rectangular cross section in the axial direction of the photoreceptor 13, but may have other shapes as shown in the first embodiment.

[0041] The present disclosure can be implemented in various other forms without departing from its spirit or main features. Therefore, the above-described embodiments are merely examples and should not be interpreted as being limited. All modifications and variations within the scope of the claims of the present disclosure are within the scope of the present disclosure. [Industrial Applicability]

[0042] According to the present disclosure, it is possible to provide an image forming apparatus that can prevent the cleaning blade from reversing with a simple configuration, and therefore it is useful as an image forming apparatus. [Explanation of symbols]

[0043] 10 Image forming device 11 Exposure equipment 12 Developing device 13 Photoreceptor 14 Cleaning device 15 Charger 16 Intermediate transfer belt device 17 Fixing device 18 Paper tray 19. Paper output tray 21 Intermediate transfer belt 22 Intermediate transfer belt drive roller 23 Intermediate transfer belt driven roller 24 Intermediate transfer roller 25 Intermediate transfer belt cleaning device 26 Secondary transfer device 26a Transfer roller 31 Pickup roller 32 Registration roller 33 Pre-registration roller 34 Paper ejection roller 35 Conveyor roller 41 Frame 42 Cleaning blade 43, 43a Cleaning blade holder (metal plate) 44a, 44b, 44c, 44d PET film (elastic member) 45,50 Lubricant 46 Development area 47 Charged Area 48 cleaning areas 49 Region where the friction coefficient μ increases

Claims

1. An image forming apparatus including a photoreceptor and a cleaning device that removes residual toner from the photoreceptor, the cleaning device includes a frame, a cleaning blade provided in the frame, extending in the longitudinal direction of the photosensitive member and contacting the photosensitive member, and a cleaning blade holder fixed to the frame and holding the cleaning blade; the cleaning device has a lubricant that contacts the photosensitive member upstream of a position where the cleaning blade contacts the photosensitive member in a rotation direction of the photosensitive member, The image forming apparatus, wherein the lubricant is fixed to a tip of an elastic member fixed to the cleaning device.

2. 2. The image forming apparatus according to claim 1, wherein the lubricant is fixed to a tip of an elastic member fixed to the frame.

3. 2. The image forming apparatus according to claim 1, wherein the lubricant is fixed to a tip of an elastic member fixed to the cleaning blade holding portion.

4. 2. The image forming apparatus according to claim 1, wherein the lubricant contacts only the outermost portions of the photosensitive member outside the development region at both ends in the longitudinal direction.

5. 2. The image forming apparatus according to claim 1, wherein the lubricant is a solid material obtained by solidifying powdered stearic acid.

Images