JP2007171805A - Electrophotographic photoreceptor and image forming apparatus equipped with the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus in which dislocation of a heating member in its axial direction is suppressed, and consequently image deletion occurs infrequently. <P>SOLUTION: The image forming apparatus is equipped with an electrophotographic photoreceptor comprising a nearly cylindrical substrate 1 and a photosensitive layer stacked on the outer circumferential surface of the substrate 1, and a planar heating member disposed within the substrate 1, wherein protrusions 1t are located on the inner circumferential surface of the substrate 1. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an electrophotographic photosensitive member and an image forming apparatus equipped with the same.

  2. Description of the Related Art Conventionally, image forming apparatuses such as electrophotographic copying machines and printers are arranged at a predetermined distance from a substantially cylindrical electrophotographic photosensitive member or an electrophotographic photosensitive member for charging the surface thereof. It is composed of a charging member, a heating member provided with a heater for heating the electrophotographic photosensitive member from the inside, and the like.

  During image formation, while rotating the electrophotographic photosensitive member, the surface of the electrophotographic photosensitive member is heated by a heating member installed inside the electrophotographic photosensitive member, and the surface of the latent image forming region is charged by a charging member. Charge uniformly. Thereafter, laser light is irradiated according to the image pattern to form a latent image on the surface of the electrophotographic photosensitive member. Further, toner is attached to the latent image, and the toner is transferred and fixed to a recording medium. Further, after the toner is transferred to the recording medium, the remaining toner is removed by rubbing a cleaning blade on the surface.

  As an electrophotographic photosensitive member used in such an image forming apparatus, one having the following structure is known. That is, an electrophotographic photosensitive member in which a substantially cylindrical substrate made of a metal material is combined with a photoconductive layer and a surface layer made of an inorganic material formed on the substrate as a photosensitive layer has been put into practical use.

  Further, as the heating member described above, the electrode wiring is stretched around the inner insulating base material in a meander shape or a spiral shape, and the outer insulating base material is arranged on the electrode wiring to sandwich the electrode wiring. Heating members are known.

  Then, such a planar heating member is rolled up into a cylindrical shape and accommodated inside the base of the electrophotographic photosensitive member. The planar heating member is accommodated so as not to deviate from a predetermined position by pressing the inner peripheral surface of the base body by an elastic force to spread inside the base body.

  By the way, when it is intended to reduce the thickness of the planar heating member in response to a request for miniaturization of the electrophotographic photosensitive member, it is necessary to reduce the thickness of the insulating base material of the planar heating member.

  However, when the planar heating member is thinned, especially the insulating base material is thinned, the elasticity of spreading inside the base described above is weakened, and therefore the force pressing the inner peripheral surface of the base is weakened. As a result, it is assumed that it deviates from a predetermined position.

  Further, when the image forming speed is increased, the rotational speed of the electrophotographic photosensitive member is increased, so that it is assumed that the image forming speed is more easily shifted.

  If the planar heating member is displaced in the axial direction inside the substrate, heating unevenness occurs in the photosensitive layer of the electrophotographic photosensitive member, and an image flow tends to occur in an area where the heating is insufficient.

  The present invention has been devised in view of the above-mentioned drawbacks, and an object of the present invention is to provide an image forming apparatus that suppresses the displacement of the heating member in the axial direction and thus hardly causes image flow. is there.

  An image forming apparatus of the present invention includes an electrophotographic photosensitive member including a substantially cylindrical base, a photosensitive layer laminated on the outer peripheral surface of the base, and a planar heating member disposed inside the base. In the image forming apparatus, a protrusion is provided on an inner peripheral surface of the base.

  The image forming apparatus according to the present invention is characterized in that the protrusion is positioned on the outer side in the axial direction than the axial end of the planar heating member.

  Furthermore, the image forming apparatus of the present invention is characterized in that the protrusion is positioned inward in the axial direction with respect to the axial end of the planar heating member.

  The image forming apparatus of the present invention is characterized in that the projection is formed by deforming a part of the substrate.

  According to the present invention, an image forming apparatus comprising an electrophotographic photosensitive member having a substantially cylindrical base, a photosensitive layer laminated on the outer peripheral surface of the base, and a planar heating member disposed inside the base. In the apparatus, a protrusion is provided on the inner peripheral surface of the base.

  Thereby, it can suppress that a planar heating member shifts | deviates to an axial direction inside the base | substrate of an electrophotographic photoreceptor.

  Further, when the protrusion is positioned outside in the axial direction with respect to the axial end of the planar heating member, even if the planar heating member is about to be displaced, the protrusion Since the side surfaces of the planar heating member collide with each other, the deviation of the planar heating member is suppressed.

  Furthermore, when the projection is positioned on the inner side in the axial direction with respect to the axial end of the planar heating member, the projection is brought into contact with the outer surface of the planar heating member. The displacement of the planar heating member is suppressed.

  Further, since the protrusion is formed by deforming a part of the base, a member for newly forming the protrusion is not required.

  And since the shift | offset | difference of a planar heating member can be suppressed, the heating nonuniformity of a photosensitive layer is suppressed and the favorable image forming apparatus with few image flows is obtained by extension.

  Hereinafter, an example according to the embodiment of the present invention will be described in detail.

  As shown in FIGS. 1 and 2, an image forming apparatus as an example of the present invention is arranged in a substantially cylindrical electrophotographic photosensitive member and a predetermined distance away from the electrophotographic photosensitive member for charging the surface thereof. The charging roller 9 is composed of a sheet heating member provided with a heater 15 for heating the electrophotographic photosensitive member from the inside.

  This type of image forming apparatus is called a Carlson method, and the following processes are repeated.

That is, while rotating the electrophotographic photosensitive member during image formation by a rotating mechanism provided at one end of the electrophotographic photosensitive member,
1. The photosensitive layer of the electrophotographic photosensitive member is heated to about 35 ° C. to 55 ° C. by the heater 15.

2. The surface of the photosensitive layer of the electrophotographic photosensitive member is charged by the charging roller 9.

3. When the image is exposed by the exposure device 10, an electrostatic latent image as a potential contrast is formed on the surface of the electrophotographic photosensitive member.

4). The electrostatic latent image is developed by the developing device 11. By this development, the toner adheres to the surface of the photoreceptor due to electrostatic attraction with the electrostatic latent image and is visualized.

5. The toner image on the surface of the photoreceptor is electrostatically transferred by applying an electric field having a polarity opposite to that of the toner from the back surface of the recording medium such as paper, whereby the image is transferred onto the recording medium.

6). Residual toner on the surface of the photoreceptor is mechanically removed by the cleaning blade 8.

7). The entire surface of the photoconductor is exposed with strong light, and the remaining electrostatic latent image is removed by the static eliminator 13.

  Hereinafter, each part of the image forming apparatus will be described in detail for each member.

  First, as an example of an electrophotographic photosensitive member used in an image forming apparatus, as shown in FIGS. 1 to 3, a substrate 1 made of a cylindrical metal and a photosensitive layer formed on the outer peripheral surface of the substrate 1. Become. The photosensitive layer further comprises a charge injection blocking layer 2, a photoconductive layer 3, a surface layer 4 and the like formed on the substrate 1.

  The substrate 1 of the electrophotographic photosensitive member has a cylindrical shape and carries an electrostatic latent image on its outer peripheral surface. Further, a protrusion 1t is formed on the inner peripheral surface. The length of the substrate 1 in the axial direction is set to be slightly longer than the length of the largest recording medium to be used, specifically, about 0.5 cm to 5 cm from both ends of the recording medium. For this reason, a non-latent image characteristic region is provided at the end of the substrate 1. Here, the non-latent image forming region is, for example, a region on the surface of the electrophotographic photosensitive member (latent latent image) that is not planned to be used at all when a latent image corresponding to any image size is formed on the surface of the electrophotographic photosensitive member. The outside of the image forming area in the axial direction). A drive transmission flange 5 for rotating the electrophotographic photosensitive member and a bearing flange 6 for holding the substrate 1 are fitted to the inner surface of the substrate 1 corresponding to the non-latent image formability region during image formation. Are provided with a drive transmission side spigot part 1 ′ and a bearing side spigot part 1 ″. The inlay portions 1 ′ and 1 ″ are formed so that the inner diameter thereof is larger than that of the non-inlay portion (the portion where the inlay portion is not formed) of the base 1. The inlay portions 1 ′ and 1 ″ do not necessarily need to be within the non-latent image forming area, and may extend to the inner surface of the substrate 1 corresponding to the latent image forming area.

As a material of such a base | substrate 1, conductive members, such as metal materials, such as Al or SUS (stainless steel), Zn, Cu, Fe, Ti, Ni, Cr, Ta, Sn, Au, Ag, those alloy materials, Alternatively, a conductive film formed by vapor deposition or the like of a conductive film made of a transparent conductive material such as the above metal, ITO, or SnO ₂ is used on the surface of an insulator such as resin, glass, or ceramic. In particular, when an Al alloy material is used, the cost is lower than when SUS is used, and the weight can be reduced. In addition, a (amorphous; below) is used for the photoconductive layer 2 and the charge injection blocking layer 4 described later. The same) -Si-based material is preferable in that the adhesion to those layers is increased and the reliability is improved.

  Further, as shown in FIG. 1, a protrusion 1t is provided on the non-inlay portion (inside the inlay portions 1 ', 1' ') of the base 1 described above. Thereby, it can suppress that a planar heating member shifts | deviates to an axial direction inside the base | substrate 1. FIG.

  When this protrusion 1t is positioned outside the axial end of the planar heating member in the axial direction, for example, the surface roughness is 0.5 μm to 2 μm in terms of arithmetic average roughness Ra, the maximum height Ry is 6 μm or less (Ra and Ry are both measured in accordance with the recommended values of JIS B0601-1994 and JIS B0633-2001). The height (from the inner peripheral surface of the base 1 is higher than the inner peripheral surface of the base 1). It is desirable to set the height in the direction toward the inside of the substrate 1 to 20 μm to 5000 μm. When the thickness is lower than 20 μm, the effect of suppressing the displacement with respect to the heating member is not sufficient. Conversely, when the thickness exceeds 5000 μm, the planar heating member is taken out when the planar heating member is disposed inside the substrate 1 or inside the substrate 1. It tends to be an obstacle.

  Further, if the projection 1t is positioned outside the axial end of the planar heating member in the axial direction, the projection 1t may be used even when the planar heating member is displaced in the axial direction. Since it collides with the side surface of the planar heating member, specifically, the insulating substrate, the displacement of the planar heating member is suppressed.

  In this case, it is desirable to set the height (referring to the height in the direction from the inner peripheral surface of the substrate 1 to the inside of the substrate 1) to 20 μm to 500 μm with respect to the inner peripheral surface of the substrate 1 described above. If it is lower than 20 μm, the effect of suppressing the displacement with respect to the heating member is not sufficient, and if it exceeds 500 μm, the planar heating member is lifted from the inner peripheral surface of the base 1 around the protrusion 1t, and the heat of the heater 15 is increased. Is not transmitted as compared with other portions, and it is easy to cause an image flow due to uneven heating of the photosensitive layer.

  When the protrusion 1t is positioned inside the axial end of the planar heating member in the axial direction, the protrusion 1t is formed on the outer surface of the planar heating member, that is, the outer insulating base material 17. , The displacement of the planar heating member is suppressed.

  Such a protrusion 1t is formed as follows. That is, it is formed by inserting a cone obliquely with respect to the inner peripheral surface of the base 1 and then raising the cone outward. Or you may form by making thin the thickness of the base | substrate 1 located inside the axial direction rather than the formation location of the projection part 1t by grinding | polishing. Further, the number of protrusions 1t may be one when there is a sufficient shift suppressing effect, and a large number may be provided when not enough. Furthermore, the shape of the protrusion 1t may be a pin shape, or may be an annular shape along the circumferential direction of the substrate 1.

  In addition, when the protrusion 1t is pin-shaped and the protrusion 1t is brought into contact with the outer insulating base material, the tip may be sharpened so that the tip bites into the outer insulating base material. By doing in this way, it becomes possible to suppress the shift | offset | difference of a planar heating member effectively. However, in this case, it is desirable that the height of the projecting portion 1t is lower than the thickness of the outer insulating base material 17 constituting the planar heating member described later. Thereby, it can suppress that the projection part 1t penetrates the outer side insulating base material 17, and contacts the heater 15. FIG.

  Further, in the case where the protruding portion 1t is annular, the effect of suppressing the shift is further increased if the protruding portion 1t is positioned outside in the axial direction with respect to the axial end portion of the planar heating member. In this case, it is desirable that the height of the protruding portion 1t is higher than the thickness of the outer insulating base material 17 constituting the planar heating member described later. Thereby, it becomes possible to more effectively suppress the displacement of the planar heating member. Needless to say, these pin-like protrusions and annular protrusions may be used in combination, or protrusions of other structures may be combined.

  Further, the protrusions 1t are provided by deforming the base body 1 by processing or the like, so that the protrusion parts 1t and the base body 1 are integrated, and a protrusion portion made of another material, such as a photo-curing resin or a thermosetting resin, is provided. Compared with the case of attaching, it is possible to prevent the protruding portion 1t itself from being peeled off from the base 1, and the mechanical strength is stabilized, and it is possible to manufacture at a lower cost.

  Furthermore, when the protrusion 1t is positioned outside the axial end of the planar heating member in the axial direction of the base 1, the protrusion 1t is not only at one end in the axial direction but at both ends. It is needless to say that the sheet heating member can be hardly displaced with respect to either of the axial directions by forming the sheet heating member and positioning the sheet heating member inside the both projecting portions 1t.

  A charge injection blocking layer 2 made of an inorganic material is provided on the outer peripheral surface of the substrate 1 described above. The charge injection element layer 2 has a function of blocking the injection of charges (electrons and holes) from the substrate 1.

  Various layers can be used for the charge injection blocking layer 2 depending on the material of the photoconductive layer 3. When the photoconductive layer 3 is made of an a-Si material, an electrophotographic film having excellent adhesion between the substrate 1 and the photoconductive layer 3 by using an a-Si material for the charge injection blocking layer 2 as well. A photoreceptor is obtained.

  When the charge injection blocking layer 2 is formed of an a-Si-based material in this way, more IIIb group elements and Vb group elements are contained or boron (B ), Nitrogen (N), and oxygen (O) to increase the resistance.

  Instead of the charge injection blocking layer 2, a long wavelength light absorption layer may be provided. Providing this long-wavelength light absorption layer suppresses the occurrence of interference fringes in the recorded image by reflecting the long-wavelength light incident during exposure (referred to as light having a wavelength of 0.8 μm or more) on the surface of the substrate 1. It becomes possible to do.

On the charge injection blocking layer 2, a photoconductive layer 3 made of an inorganic material is deposited. Examples of the photoconductive layer 3 made of this inorganic material include a-Si or a-Se such as a-Se, Se-Te, As ₂ Se ₃ or II-VI such as ZnO, CdS, CdSe. Group compounds can be used. Note that, instead of the above-described photoconductive layer 3 made of an inorganic material, a photoconductive layer or an OPC photoconductive layer in which the above-mentioned inorganic material is made into particles and dispersed in resin can also be used. In particular, when using an a-Si material of a-Si or an alloy obtained by adding C, N, O, etc. to a-Si, such as high photosensitivity characteristics, high-speed response, repeated stability, heat resistance, durability, etc. It is preferable in that excellent electrophotographic characteristics can be stably obtained and the compatibility with the a-SiC: H surface layer 4 is excellent.

  Examples of the a-Si based material include a-Si, a-SiC, a-SiN, a-SiO, a-SiGe, a-SiCN, a-SiNO, a-SiCO, a-SiCNO, and the like. These are formed by, for example, a glow discharge decomposition apparatus, various sputtering apparatuses, various vapor deposition apparatuses and the like shown in FIG. 5, and in forming the film, hydrogen (H) or halogen elements (F, Cl) are used for dangling bond termination. ) In an amount of 1 to 40 atomic%. In addition, in order to obtain desired characteristics of the electrical characteristics such as dark conductivity and photoconductivity of each layer and optical band gap, group IIIb elements (hereinafter abbreviated as group IIIb elements) and Vb By adding 0.1 to 20000 ppm of a group element (hereinafter abbreviated as a Vb group element) or adjusting the content of elements such as C, N, and O in the range of 0.01 to 100 ppm, the above characteristics can be achieved. adjust.

  As these IIIb group element and Vb group element, boron (B) and phosphorus (P) are desirable in that they can excel in the covalent bond property and can change the semiconductor characteristics sensitively and can provide excellent photosensitivity. And when it is made to contain with elements, such as C, N, and O, 0.1-20,000 ppm is good for a IIIb group element, and 0.1-10000 ppm is good for a Vb group element.

  Further, when elements such as C, N, O, etc. are not contained, or when a trace amount (0.01-100 ppm) is contained, 0.01-200 ppm of IIIb group elements and 0.01-100 ppm of Vb group elements are contained. Good. The content of these elements may be provided with a gradient over the layer thickness direction, in which case the average content of the entire layer may be within the above range.

  Further, the a-Si-based material may include μc-Si (microcrystalline silicon), and when this μc-Si is included, the dark / photoconductivity can be increased. There is an advantage that the degree of freedom of design increases. Such μc-Si can be formed by employing the same formation method as described above and changing the film formation conditions. For example, in the glow discharge decomposition method, it can be formed by setting the substrate temperature and high-frequency power higher than in the case of a-Si and increasing the flow rate of hydrogen as a dilution gas. Further, when μc-Si is included, an impurity element similar to the above may be added.

A surface layer 4 made of an inorganic material for protecting the photoconductive layer 3 from sliding contact with the recording medium is deposited on the photoconductive layer 3 described above. When the surface layer 4 is made of, for example, a-SiC: H (which is made of a-SiC and contains hydrogen, which is the same hereinafter), the thickness is preferably 0.2 to 1.5 μm. The surface layer is made of a-SiC: H, and the element ratio is expressed by the composition formula a-Si _1-X C _X : H, and the X value is 0. .55 ≦ X <0.93, preferably 0.6 ≦ X ≦ 0.7.

  By setting the thickness to 0.2 μm or more, it is possible to prevent image scratches and image density unevenness due to printing durability, and by setting the thickness to 1.5 μm or less, initial characteristics (image defects due to residual potential, etc.) Can be improved. Further, by setting the X value to 0.55 or more, it is possible to obtain an appropriate hardness, ensuring durability, and by setting it to less than 0.93, an appropriate hardness can be obtained similarly.

  In addition, about H content of the surface layer 4 which consists of a-SiC: H, it is good to set to about 1-70 atomic%. Within this range, the number of Si—H bonds is smaller than that of Si—C bonds, and trapping of charges generated when the surface of the surface layer 4 is irradiated with light can be suppressed, and residual potential is prevented. It is preferable in that it can be performed. According to the knowledge of the present inventor, better results can be obtained when the H content is about 45 atomic% or less.

  Next, the planar heating member of the present invention will be described with reference to FIG. The planar heating member according to an example of the embodiment of the present invention has a configuration in which a heater 15 is sandwiched between an inner insulating substrate 16 and an outer insulating substrate 17.

  The insulating base materials 16 and 17 are made of an insulating resin such as silicon resin, PET (polyethylene terephthalate), or acrylic resin. Each of the inner and outer insulating base materials is appropriately set to have a thickness of 0.5 mm to 3.5 mm.

  The heater 15 is formed by patterning the insulating base material 16 so that heat is generated in a planar shape, for example. The material of the heater 15 can be used without particular limitation as long as it generates heat when energized. As an example, a nichrome wire, a copper wire, or the like drawn around, or those metal materials formed on an insulating substrate may be used. In addition to metal materials, carbon-based and metal oxide-based heat generating materials can also be used.

  And such a planar heating member is accommodated in the inside of the base | substrate 1 by rounding what formed the flat sheet shape into a cylinder shape. Furthermore, when it accommodates in the inside of the base | substrate 1, the insulating base materials 16 and 17 press the inner peripheral surface of the base | substrate 1 with the elasticity. Thereby, a planar heating member is arrange | positioned in a predetermined location, without using a screw, an adhesive agent, etc. especially.

  This planar heating member energizes the heater 15 when the image forming apparatus is used, and the photosensitive layer of the electrophotographic photosensitive member is heated to 35 ° C. to 55 ° C. As a result, moisture is removed from the surface of the photosensitive layer, and image flow is suppressed.

  1 and 2, the image forming apparatus of the present invention includes a drive transmission unit 5 (drive transmission flange), a bearing unit 6 (bearing flange), a gear 7 and the like which are rotation mechanisms of the electrophotographic photosensitive member. I have. Further, a charging roller 9 that presses the peripheral surface of the electrophotographic photosensitive member, an exposure device 10 (LED head or laser) that irradiates light onto the surface of the electrophotographic photosensitive member after charging, and a toner image on the surface of the electrophotographic photosensitive member. A developing device 11 having toner for forming the toner, a transfer device 12 for transferring the toner image to a recording medium, a cleaning blade 8 for removing residual toner on the surface of the photoreceptor after the transfer, and a residual static after the transfer. And a static eliminator 13 for removing the electrostatic latent image. Further, a fixing device 14 is provided for fixing the toner image transferred to the recording medium by heat or pressure.

  The drive transmission flange 5 provided for rotating the above-described electrophotographic photosensitive member is fitted into the drive transmission side inlay portion 1 ′ of the base 1. The drive transmission flange 5 has an outer diameter that substantially coincides with the inner diameter of the drive transmission side spigot portion 1 ′, thereby reliably supplying the rotational power from the gear 7 without requiring a screw or the like. Can be communicated to. Further, in order to transmit the rotation from the gear 7 to the base body 1, teeth that mesh with the teeth engraved on the gear 7 are also engraved on the drive transmission flange 5.

  The drive transmission unit is not limited to this flange, and may have another structure as long as it can apply a predetermined rotational force to the electrophotographic photosensitive member. Without limitation, it may be a rotating belt or a chain. The gear 7 rotates the electrophotographic photosensitive member at a constant speed, for example, 320 mm / sec.

  On the other hand, the bearing flange 6 is fitted into the bearing side inlay portion 1 ″ which is the other end of the base 1 of the electrophotographic photosensitive member. Unlike the drive transmission flange 5, the bearing flange 6 is not applied with a rotational force. The fitting portion between the bearing side inlay portion 1 ″ and the bearing flange 6 has a slight play (gap) as compared with the fitting portion between the drive transmission side inlay portion 1 ′ and the drive transmission flange 5.

  The cleaning blade 8 used in the image forming apparatus is disposed so that the tip thereof is in sliding contact with the latent image forming area of the electrophotographic photosensitive member, and scrapes residual toner from the surface of the surface layer 4 of the electrophotographic photosensitive member. Play a role. Such a cleaning blade 8 is made of, for example, a rubber material mainly composed of polyurethane resin, and is pressed by a biasing means such as a spring provided on the side opposite to the sliding contact surface of the surface layer 4.

  The cleaning blade 8 is set to have a thickness of 1.0 to 1.2 mm on the tip side (side in contact with the surface layer 4) and a blade linear pressure of 14 gf / cm (generally 5 to 30 gf / cm). It is set to be. The cleaning blade has a JIS hardness of 74 degrees (preferable range 67 to 84 degrees).

  Further, the charging roller 9 may be one in which a conductive rubber is coated on a metal core and further a surface coating of PVDF (polyvinylidene fluoride) is performed. The charging roller 9 is installed for the purpose of charging the electrophotographic photosensitive member by contact with the photosensitive member.

  Further, the exposure device 10 irradiates the surface of the photoconductor with light having a specific wavelength (650 nm to 780 nm) for the purpose of forming a latent image on the surface of the photoconductor. In the image forming apparatus of the present invention, an LED head in which the wavelength of LED light is 680 nm and the light emitting elements are arranged at a density of 600 dpi can be employed.

  Further, the developing device 11 is installed to form a toner image on a portion holding an electric charge on the electrophotographic photosensitive member on which the latent image is formed. It consists of a wheel called a roller for controlling the distance between the magnetic roller for magnetically holding the toner and the stirrer for stirring the toner.

  Further, the transfer device 12 applies a bias opposite to that of the charging roller 9 to the electrophotographic photosensitive member in order to transfer the toner image formed on the electrophotographic photosensitive member to a recording medium (transfer object) such as paper. Is for. Usually, a DC bias voltage in which an AC component is superimposed is applied.

  Further, the static eliminator 13 uniformly irradiates the surface of the electrophotographic photosensitive member with a light source such as an LED in order to erase all charges remaining on the photosensitive layer of the electrophotographic photosensitive member. As a result, the history of the previous rotation on the photosensitive member is completely erased.

  The fixing device 14 is installed in order to fix a toner image formed on a transfer object such as paper to the transfer object. Usually, a toner image is fixed by pressing a transfer object with a roller in which a surface coating such as Teflon (registered trademark) is applied on a heated metal roller.

  In this embodiment, the configuration of a printer is described as an example of the image forming apparatus. However, instead of the exposure device 10 such as an LED head, an optical system including a laser beam or a polygon mirror, or reflected light from a document. If an optical system composed of a lens, a mirror, or the like is used, an image forming apparatus having a configuration of a copying machine is obtained.

The image forming apparatus uses normal dry development, but can also be applied to liquid developers used for wet development.

  Thus, in the image forming apparatus of the present invention, while rotating the electrophotographic photosensitive member, the photosensitive layer of the electrophotographic photosensitive member is heated by the planar heating member installed inside the electrophotographic photosensitive member, and a latent image is formed. The surface of the formation region is uniformly charged by the charging member. Thereafter, laser light is irradiated according to the image pattern to form a latent image on the surface of the electrophotographic photosensitive member. Further, toner is attached to the latent image, and the toner is transferred and fixed to a recording medium. Further, after the toner is transferred to the recording medium, the remaining toner is removed by rubbing a cleaning blade on the surface.

  Hereinafter, specific examples of the electrophotographic photoreceptor of the present invention will be described. However, the present invention is not limited to the following examples, and various changes and improvements may be made without departing from the scope of the present invention.

Table 1 below shows the dimensions of the substrate 1 of the electrophotographic photosensitive member of the example and the film forming conditions of the charge injection blocking layer 2, the photoconductive layer 3, and the surface layer 3. The substrate 1 is made of A5052 TDS aluminum alloy seamless pipe (JIS H4080-1988). Further, the RF power, reaction gas flow rate, dilution gas flow rate and the like of each layer under the photosensitive layer deposition conditions shown in Table 1 are values per glow discharge decomposition apparatus.

  Protrusions shown in Table 2 were provided on the inner peripheral surface of the base 1 thus obtained. In Table 2, no. 1-No. 16 is the present invention. 17 and no. 18 is a comparative example. Further, the height of the protrusion 1t is a height in a direction from the inner peripheral surface of the base 1 toward the inside of the base 1. The position of the protrusion 1t indicates whether the position where the protrusion 1t is provided is on the outer side or the inner side in the axial direction with respect to the end in the axial direction of the planar heating member disposed inside the substrate 1. . Further, the type of the heating member is the type of the planar heating member disposed inside the base body 1. In the example, the evaluation is performed using two types of the planar heating member A and the planar heating member B. Displacement of the planar heating member means that after arranging the planar heating member inside various electrophotographic photosensitive members, the arrangement of the inner peripheral surface of the substrate 1 and the heating member is marked in advance, and the arrangement is performed after running evaluation. This is a result of visually observing the change. The image determination result is a result of comprehensively judging the image flow and the degree of image density unevenness with respect to the image obtained by the running evaluation (◯: good, x: image flow or density unevenness present). . For running evaluation, an electrophotographic photosensitive member is incorporated in the image forming apparatus shown in FIG. 2, and 5,000 A3-size white papers are printed as a recording medium. As an environment for running evaluation, room temperature is 15 ° C. and humidity is 30%. The planar heating member disposed inside the substrate 1 is temperature-controlled so that the substrate temperature becomes 40 ° C. while monitoring the temperature of the inner peripheral surface of the substrate 1.

The planar heating member A of the present example is drawn around a heating resistor in which a nichrome wire having a cross-sectional area of 0.5 mm ² is covered with silicon rubber, and PET (polyethylene terephthalate) having a thickness of 0.5 mm is used as the outer insulating base material 17. Used, PET having a thickness of 1 mm is used as the inner insulating base material 16 and the heater 15 is sandwiched between the two insulating base materials. In addition, PET which is an insulating substrate has a durometer hardness of 70 (type D JIS K 7215-1986).

The planar heating member B is used with a nichrome wire cross-sectional area 1mm ² is a heat generating resistor as a heater 15, which is sandwiched by the silicon rubber sheet having a thickness of 1mm is an insulating substrate 16, 17. This silicon rubber sheet has a spring hardness of 30 (C-type testing machine JIS K 6301-1975). In the running evaluation, a corona charger is used as the charging member of the image forming apparatus in FIG. 2, and an LED head having a wavelength of 680 nm is used as the exposure member. At this time, the speed of the electrophotographic photosensitive surface is 240 mm / sec.

  No. in Table 2 1-4 and No.1. Nos. 9 to 12 have the protrusion 1t positioned only on one end side outside the end in the axial direction of the planar heating member. No. 5-8 and no. Reference numerals 13 to 16 indicate that the protrusion 1t is positioned only at one position inside the end of the heating member in the axial direction. No. 1, 5, 9, and 13 were used to water aluminum oxide media (WHITE ABRAX # 80 Nippon Abrasives Co., Ltd.) on the inner peripheral surface of the substrate 1 with a liquid honing device (LH-10, Fuji Seiki Seisakusho). The protrusion 1t is provided by striking together with the inner peripheral surface. No. 2, 3, 6, 7, 10, and 14 are obtained by pressing the cutting edge of a super steel precision scraper (SC5500 Noga Japan Co., Ltd.) against the inner peripheral surface of the substrate 1, thereby partially forming the aluminum alloy as the substrate 1. Are deformed and raised to provide protrusions. No. 4, 8, 11, 12, 15 and 16 are formed by bonding a conical epoxy resin projecting member to the inner peripheral surface of the base 1 using an epoxy adhesive (Petropoxy 154 PALOUSE PETRO). Yes. No. In all of Nos. 1 to 16, there was no deviation of the heating member after running evaluation, and there was no image flow or image density unevenness.

  On the other hand, no. Although 17 and 18 are comparative examples, the deviation of the heating member has been confirmed after running evaluation. No. In FIGS. 17 and 18, the sheet heating member was displaced with respect to the axial direction of the substrate 1. No. Since both 17 and 18 have no protrusions, the heating member is displaced during running evaluation, and the temperature of the electrophotographic photosensitive member becomes non-uniform and unstable, resulting in image flow and density unevenness.

1 is a partial cross-sectional view of an image forming apparatus according to an example of an embodiment of the present invention. It is a fragmentary sectional view of an image forming device concerning other examples of an embodiment of the present invention. 1 is a cross-sectional view illustrating a layer configuration of an electrophotographic photoreceptor according to an example of an embodiment of the present invention. It is a perspective view of the planar heating member concerning an example of the embodiment of the present invention. (A) is a top view which shows an example of the film-forming apparatus of the electrophotographic photoreceptor of this invention, (b) is the sectional drawing.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Base | substrate 2 ... Charge injection | blocking prevention layer 3 ... Photoconductive layer 4 ... Surface layer 5 ... Drive transmission part (drive transmission flange)
6 ... Bearing part (bearing flange)
7 ... Gear 8 ... Cleaning blade 9 ... Charging roller 10 ... Exposure device (LED head)
DESCRIPTION OF SYMBOLS 11 ... Developing device 12 ... Transfer device 13 ... Static eliminator 14 ... Fixing device 15 ... Heater 16 ... Inner insulating base material 17 ... Outer insulating base material 18 ... Reaction chamber outer wall 19 ... gas introduction pipe 20 ... gas introduction port

Claims (4)

An image forming apparatus comprising an electrophotographic photosensitive member having a substantially cylindrical base and a photosensitive layer laminated on the outer peripheral surface of the base, and a planar heating member disposed inside the base,
An image forming apparatus comprising a protrusion provided on an inner peripheral surface of the base. The image forming apparatus according to claim 1, wherein the protruding portion is positioned outside in an axial direction with respect to an axial end portion of the planar heating member. The image forming apparatus according to claim 1, wherein the protrusion is positioned on an inner side in an axial direction than an end of the planar heating member in the axial direction. The image forming apparatus according to claim 1, wherein the protrusion is formed by deforming a part of the base.

Images