JP4335291B2 - Fixing apparatus and recording apparatus - Google Patents

Description

  The present invention relates to a fixing device that fixes a toner image transferred onto a medium by applying heat and pressure by a fixing member.

  A conventional fixing device used in an electrophotographic recording apparatus or the like includes a fixing roller having a heater disposed therein and a pressure roller that rotates while pressing the fixing roller. The sheet on which the toner image is transferred is nipped between the fixing roller and the pressure roller and conveyed. At this time, the sheet is conveyed so that the surface onto which the toner image is transferred faces the fixing roller, and the toner is melted and fixed on the sheet by heat applied from the fixing roller and pressure from the pressure roller.

  Since the melted toner has adhesiveness, it becomes easy to stick to the fixing roller. In order to reliably separate the sheet from the fixing roller, conventionally, the separation claw is disposed in contact with the fixing roller, and the sheet is peeled off from the fixing roller (see, for example, Patent Document 1).

JP-A-10-171293 (page 3, FIG. 1)

  However, in the conventional fixing device, since the separation claw is in contact with the fixing roller, the fixing roller is damaged at the contact portion of the separation claw, or toner that cannot be fixed is accumulated on the separation claw, causing the print stain. It becomes. In addition, there is a problem that the surface condition and surface roughness of the fixing roller change at the contact portion of the separation claw, which causes uneven gloss of printing.

The fixing device according to the present invention is a toner image adhered to the medium fixing device for fixing by applying heat and pressure,
A fixing member that is in pressure contact with the pressure member, a separation plate that is disposed in close proximity to and substantially parallel to the fixing member, and is positioned on the longitudinal direction side of the separation plate and has a gap between the longitudinal end portion of the separation plate The frame that supports the separation plate in a state of being separated and the longitudinal end portion of the separation plate are urged in the longitudinal direction of the separation plate to allow variation in the gap between the longitudinal end portion and the frame. The separation plate includes a flat portion in which a distance between the front end facing the fixing member and the fixing member is set to a predetermined value, and on the opposite side of the flat portion and the front end. that a provided bending portion you characterized.

According to the present invention, since the sheet is separated from the fixing member by the separation plate arranged without directly contacting the fixing member, the printing by the separation member coming into contact with the fixing member without damaging the fixing member. The occurrence of defects can be prevented.
Furthermore, since the thermal expansion of the separation plate can be absorbed, the space of the medium conveyance path can be secured stably.

Embodiment 1 FIG.
Embodiments of the present invention will be described with reference to the drawings. In addition, the same code | symbol is attached | subjected to the element common to each drawing. FIG. 1 is a perspective view showing a fixing device according to a first embodiment of the present invention, and FIG. 2 is a side sectional view showing the fixing device according to the first embodiment.

  1 and 2, the fixing device 1 according to the first embodiment includes side frames 2 and 3 on the left and right sides, and an upper plate 4 and a lower plate 5 on the upper and lower sides. The upper plate 4 and the lower plate 5 are fixed to the left and right plates 2 and 3. A fixing roller 6 and a pressure roller 7 are rotatably attached to the left side plate 2 and the right side plate 3 via bearings, respectively. The fixing roller 6 and the pressure roller 7 constitute a fixing member in the present invention.

  A gear 8 is attached to the rotation shaft of the fixing roller outside the right side plate 3. Rotation from a drive motor (not shown) is transmitted to the gear 8 and the fixing roller 6 rotates. The pressure roller 7 is attached to the left side plate 2 and the right side plate 3 via bearings so as to be movable in the vertical direction, and is a boss 9 (the left side is not shown) attached to the outside of the left side plate 2 and the right side plate 3 for rotation. Is not urged upward by the spring 10, and is pressed against the fixing roller 6.

  A separation plate 11 is provided in parallel with the fixing roller 6 over the entire length of the fixing roller 6. The separation plate 11 is fixed to the left side plate 2 and the right side plate 3 with screws 12 and 13. The gap between the leading end portion 11a of the separation plate 11 and the fixing roller 6 is set to a predetermined value. In other words, even when the sheet on which the toner is fixed adheres to the surface of the fixing roller 6 and is fed out while rotating, the position where the leading end of the sheet abuts on the lower surface of the leading end 11 a of the separation plate 11 is set. .

  A separation plate 14 is provided in parallel with the pressure roller 7 over the entire length of the pressure roller 7. The separation plate 14 is fixed to the left side plate 2 and the right side plate 3 with screws 15 and 16. The gap between the tip 14a of the separation plate 14 and the pressure roller 7 is set to a predetermined value, but the value of the gap does not require strictness. As can be seen from FIG. 2, the separation plate 11 and the separation plate 14 are arranged in a substantially horizontal state so that the paper can be easily conveyed between the plates 11 and 14.

  Next, the fixing operation in the first embodiment will be described. In FIG. 2, the fixing roller 6 is rotated clockwise by a drive motor (not shown). The pressure roller 7 in pressure contact with the fixing roller 6 rotates counterclockwise by the rotation of the fixing roller 6. The sheet 19 to which the unfixed toner 18 is transferred is conveyed in the direction of arrow A. The toner 19 is melted by the pressure from the fixing rollers 6 and 7 on the paper 19 and is fixed on the paper 19.

  FIG. 3 shows a sheet separation operation according to the first embodiment. The melted toner 18 has adhesiveness and sticks to the surface of the fixing roller 6. Accordingly, the sheet 19 that has passed through the pressure contact portion between the fixing roller 6 and the pressure roller 7 is conveyed while being adhered to the surface of the fixing roller 6. However, normally, the toner 18 is not transferred near the front end 19 a of the paper 19, and the paper 19 is stiff, so the front end 19 a is not attached to the surface of the fixing roller 6. That is, a relatively weak portion of the paper 19 sticks to the surface of the fixing roller, but the tip 19a is slightly separated from the surface of the fixing roller 6 as shown in FIG.

  Therefore, when the sheet 19 is conveyed in this state, the leading end 19a hits the lower surface of the leading end 11a of the separation plate 11, and the sheet 19 is conveyed below the separation plate 11. That is, the paper 19 is separated from the fixing roller 6 by the separation plate 11. The separated sheet 19 is discharged between the separation plate 11 and the lower separation plate 14.

  The gap between the separation plate 11 and the fixing roller 6 needs to be set smaller than the distance at which the leading end 19a of the sheet 19 is separated from the fixing roller 6. The distance at which the leading end 19a is separated from the fixing roller 6 is the type of the sheet 19 In particular, since the stiffness of the paper varies, the vicinity of the leading edge of the weakest paper among the papers 19 to be handled is set to be smaller than the distance away from the fixing roller. Specifically, when the weakest paper has a continuous amount of 50 kg (the continuous amount is the weight of printing paper per 1000 sheets), the gap between the separation plate 11 and the fixing roller 6 is about 1 mm. Set to.

  FIG. 4 shows in detail the setting of the gap between the separation plate 11 and the fixing roller 6. FIG. 5 shows the relationship between the leading edge of the paper and the margin area. In the fixing device of the electrophotographic recording apparatus, the distance L from the leading end Q of the sheet 19 to the front end P of the printing area 19b of the sheet 19 is set to a predetermined value. This is called a margin area (top margin), and printing is prohibited at a position closer to the leading edge Q of the paper than this.

That is, since the toner is not transferred to the margin area, the vicinity of the front end portion 19a of the sheet does not stick to the fixing roller. However, since toner adheres in the printing area 19b behind P, the printing area 19b of the paper is wound around the fixing roller 6. Here, the blank area extends in a direction substantially tangent to the circumferential surface of the fixing roller 6. Here, when considering a right triangle whose angle OPQ is a right angle, there is the following relationship from the three square theorem.

Therefore,

  The leading end 11a of the separation plate 11 needs to be installed so as to be closer to the surface of the fixing roller 6 than the leading end Q of the sheet. Therefore, d must be in the following range.

  As described above, according to the first embodiment, since the sheet 19 is separated from the fixing roller by the separation plate 11 disposed without contacting the fixing roller 6, the separation member is not damaged without damaging the fixing roller. It is possible to prevent a printing defect from occurring due to the contact with the fixing roller 6.

  The separation plate 14 on the pressure roller 7 side, together with the separation plate 11, forms a conveyance path for conveying the fixed paper. When the paper 19 is attached to the pressure roller 7 due to the toner image formed on the pressure roller 7 side of the paper 19, the separation plate 14 separates the paper 19 from the pressure roller 7. It has the function to do. Therefore, the gap between the separation plate 14 and the pressure roller 7 is set to the same length as the gap between the separation plate 11 and the fixing roller 6.

Embodiment 2. FIG.
6 is a front view showing the fixing device of the second embodiment, FIG. 7 is a side view showing the fixing device of the second embodiment, and FIG. 8 is a front view showing the separation plate of the second embodiment. 6 and 7, the fixing device 20 according to the second embodiment has a left side plate 2, a right side plate 3, an upper side plate 4 and a lower side plate 5 as in the first embodiment, and the left side plate 2 and the right side plate. 3, a fixing roller 6 and a pressure roller 7 are rotatably mounted.

  A separation plate 21 is disposed in parallel with the fixing roller 6 over the entire length of the fixing roller 6. The separation plate 21 is fixed to the left side plate 2 and the right side plate 3 with screws 22 and 23. The attachment portion 21 a of the separation plate 21 is fixed between the left side plate 2 and the washer 33 by the screw 22, and the opposite attachment portion 21 b is fixed between the right side plate 3 and the washer 34 by the screw 23. As shown in the figure, the separation plate 21 has a shape in which the attachment portions 21a and 21b at both ends are bent inward before being attached, and the attachment portions 21a and 21b of the separation plate 21 are It is bent inward from 80 ° to 89 °. When the separation plate 21 is fixed to the left side plate 2 and the right side plate 3, as shown in FIG. 9, the attachment portions 21a and 21b are spread outward, so that the central portion of the separation plate 21 is warped upward. In FIG. 9, a solid line shows the state after attachment, and a dotted line shows the state before attachment.

  A separation plate guide 24 is fixed to the left side plate 2 and the right side plate 3 with screws 25 and 26. The separation plate guide 24 is attached in contact with the upper surface of the separation plate 21, and presses the separation plate 21 from above, thereby pushing down the warpage of the central portion of the separation plate 21 generated at the time of attachment, and at least the separation plate 21. The tip portion 21c of the is in a horizontal state. In the horizontal state, the gap between the tip 21c of the separation plate 21 and the fixing roller 6 is set to about 1 mm.

  A separation plate 27 disposed in parallel with the pressure roller 7 is fixed to the left side plate 2 and the right side plate 3 by screws 28 and 29, respectively. The attachment portion 27 a of the separation plate 27 is fixed between the left side plate 2 and the washer 35 by the screw 28, and the opposite attachment portion 27 b is fixed to the screw 29 between the right side plate 3 and the washer 36. Similarly to the separation plate 21, the separation plate 27 has a shape in which the attachment portions 27a and 27b at both ends are bent inward before being attached, and the attachment portions 21a and 21b of the separation plate 21 are not attached. In the state, it is bent inward from 80 ° to 89 ° with respect to the main body portion. When fixed to the left side plate 2 and the right side plate 3, the attachment portions 27a and 27b are spread outward, so that the central portion of the separation plate 27 is warped downward.

  A separation plate guide 30 is fixed to the left side plate 2 and the right side plate 3 by screws 31 and 32. The separation plate guide 30 is attached to the separation plate 27 so as to be in contact with the lower surface. By pressing the separation plate 27 from below, the warp of the central portion of the separation plate 27 generated at the time of attachment is pushed up. The front end portion 27c is in a horizontal state.

  Next, the fixing operation of the second embodiment will be described. In FIG. 7, the fixing roller 6 is rotated clockwise by a drive motor (not shown). The pressure roller 7 in pressure contact with the fixing roller 6 rotates counterclockwise by the rotation of the fixing roller 6. The sheet 19 on which the unfixed toner 18 is transferred is conveyed in the direction of arrow A. When the sheet 19 enters between the fixing roller 6 and the pressure roller 7, the toner 18 is melted by the heat from the fixing roller 6 and the pressure from the rollers 6 and 7, and is fixed on the sheet 19.

  The melted toner 18 has adhesiveness and sticks to the surface of the fixing roller 6. Accordingly, the sheet 19 that has passed through the pressure contact portion between the fixing roller 6 and the pressure roller 7 is conveyed while being stuck to the surface of the fixing roller 6. As described above, since the leading end 19 a of the sheet 19 is separated from the surface of the fixing roller 6, the leading end 21 c of the separation plate 21 enters the gap to separate the sheet 19 from the fixing roller 6.

  Since the separation plates 21 and 27 are disposed near the fixing roller 6, the separation plates 21 and 27 may thermally expand due to heat from a heat roller (not shown) provided inside the fixing roller 6. In the present embodiment, the separation plate 21 has a warp that bends upward and is forcibly maintained in a horizontal state by the separation plate guide 24, so that the center portion is always upward when it thermally expands. Since the upper separation plate is thermally expanded, there is no possibility that the center portion bends toward the conveyance path side of the sheet 19 to narrow the conveyance path.

  Further, the lower separation plate 27 has a warp that bends downward, and is forcedly maintained in a horizontal state by the separation plate guide 30, so that it always bends downward when thermally expanded. Therefore, the conveyance path of the paper 19 is not narrowed by the deformation of the separation plate, and the height of the conveyance path can always be ensured sufficiently. Even if the separation plates 21 and 27 are thermally expanded, the amount of deformation is restricted by the separation plate guides 24 and 30, so that they are not greatly deformed and affect the separation of the sheet 19 from the fixing roller 6. Never give.

  As described above, according to the second embodiment, in addition to the same effects as in the first embodiment, the height of the conveyance path of the paper 19 is always set even when the separation plates 21 and 27 are thermally expanded. There is an effect that can be secured sufficiently.

Embodiment 3 FIG.
FIG. 10 is a front view showing the fixing device according to the third embodiment, and FIG. 11 is a perspective view showing the main part of the third embodiment. The fixing device according to the third embodiment uses a configuration different from that of the second embodiment to absorb expansion of the separation plate.

  In FIG. 10, the fixing device 40 of the third embodiment includes the left side plate 2 and the right side plate 3, the upper side plate 4 and the lower side plate 5, and the left side plate 2 and the right side plate 3, as in the first embodiment. Further, the fixing roller 6 and the pressure roller 7 are rotatably mounted.

  A separation plate 41 is disposed in parallel with the fixing roller 6 over the entire length of the fixing roller 6. The separation plate 41 is fixed to the left side plate 2 and the right side plate 3 by screws 22 and 23, respectively. The attachment portion 41a of the separation blade 41 is fixed between the left side plate 2 and the washer 33 by the screw 22, and the opposite attachment portion 41b is screwed between the right side plate 3 and the washer 34 via the compression spring 42. 23. As shown in FIG. 11, the total length in the longitudinal direction of the separation plate 41 is made shorter than the distance between the left side plate 2 and the right side plate 3 so that a gap 43 is formed between the separation plate 41 and the right side plate 3. It has become. Although not shown, the screw hole formed in the attachment portion 41b of the separation plate 41 through which the screw 23 passes is sufficiently larger than the diameter of the shaft of the screw 23, and is slightly larger than the attachment portion 41b. It is designed to allow movement.

  A separation plate 44 arranged in parallel with the pressure roller 7 is fixed to the side frames 2 and 3 by screws 28 and 29, respectively. The mounting portion 44a of the separation plate 44 is fixed between the left side plate 2 and the washer 35 by screws 28, and the opposite mounting portion 44b is screwed between the right plate 3 and the washer 36 with a spring 45 interposed therebetween. 29. A gap 43 is provided between the attachment portion 44 b of the separation plate 44 and the right side plate 3 in the same manner as the attachment portion 41 b of the separation plate 41.

  Next, the fixing operation of the third embodiment will be described. The fixing operation by the fixing device 40 and the operation of separating the sheet 19 from the fixing roller 6 by the separation plate 44 are the same as in the first embodiment. When the separation plate 41 expands due to heat from a heat roller (not shown) provided inside the fixing roller 6, the mounting portion 41 b of the separation plate 41 moves in a direction approaching the right side plate 3. Since the gap 43 is provided between the mounting portion 41b and the right side plate 3, the mounting portion 41b moves without difficulty to approach the right side plate 3. That is, the thermal expansion can be absorbed while the separation plate 41 is kept horizontal. When the main body portion of the separation plate 41 expands, the attachment portion 41b may move in the vertical direction. However, in this embodiment, since the screw hole of the attachment portion 41b is formed large, the attachment portion 41b can be moved in the vertical direction, and the separation plate 41 is not particularly deformed.

  Similarly, when the separation plate 44 is thermally expanded, the attachment portion 44b of the separation plate 44 moves in a direction approaching the right side plate 3. Since the gap 43 is provided between the mounting portion 44b and the right side plate 3, the mounting portion 44b moves toward the right side plate 3 without difficulty. That is, thermal expansion can be absorbed while the separation plate 44 is kept horizontal.

  As described above, in the third embodiment, even when the upper and lower separation plates 41 and 44 are thermally expanded, they move while maintaining a horizontal state, so that the height of the sheet conveyance path can always be sufficiently secured.

  Next, a modification of the third embodiment will be described. 12 and 13 are explanatory views showing a first modification of the third embodiment. In FIG. 12, in this modification, the separation plate 41 is formed of an elastic body, and the mounting portion 41 a is fixed to the outside of the right side plate 3 with screws 23. The separation plate 41 extends outward through a hole 47 formed in the right side plate 3.

  When the separation plate 41 is thermally expanded, the main body portion 41c of the separation plate 41 extends in the arrow B direction shown in FIG. Since there is nothing to restrict the movement in this direction, the main body portion extends in the same direction, and the attachment portion 41b is deformed as shown in FIG. Thereby, thermal expansion is absorbed.

  As described above, the first modification has the same effect as that of the third embodiment, but in addition, the number of parts and the number of manufacturing steps can be reduced.

  FIG. 14 is a perspective view showing a second modification of the third embodiment. In FIG. 14, in the modified example 2, the upper separation plate 51 has a main body portion 51c having a substantially L-shaped side section and attachment portions 51a and 51b at both ends. The attachment portion 51 a is fixed to the inside of the left side plate 2 with a screw 52. The opposite mounting portion 51 b is fixed by an outer screw 53 of the right side plate 3. The separation plate 51 protrudes from the notch 54 formed on the right side plate 3 to the outside of the right side plate 3. The separation plate 51 is formed of an elastic body, and like the first modification, the main body portion 51c extends in the longitudinal direction due to thermal expansion, and the attachment portion 51b is deformed.

  The body portion 51c of the separation plate 51 is provided with a plurality of cutouts 55 formed from the vertical portion 51d to the horizontal portion 51e. This notch 55 is for escaping water vapor and water droplets due to moisture adhering to the paper and toner. By forming such a notch 55, the paper is deformed by the water vapor accumulated near the separation plate 51 and the separation plate 51 is moved to. It is possible to prevent image deterioration due to contact of the paper and adhesion of water vapor or water droplets.

  As shown in FIG. 15, the shape of the notch 55 provided in the horizontal portion 51e is formed so that its width gradually increases from the upstream side to the downstream side in the paper transport direction (arrow A direction). By adopting such a shape, when the sheet comes into contact with the separation plate 51, the corner of the sheet is prevented from being caught by the notch 55. Further, by forming the notch 55 up to the vertical portion 51d of the separation plate 51, it is possible to further prevent the corner of the paper from being caught.

  The lower separation plate 56 is formed of an elastic body and has a planar main body portion 56c and attachment portions 56a and 56b at both ends. The attachment portion 56 a is fixed to the inside of the left side plate 2 by screws 57. The opposite planar mounting portion 56 b is fixed to a mounting plate 61 provided inside the right side plate 3 with screws 58. A long hole 59 is formed in the attachment portion 56b along the longitudinal direction of the separation plate 56, and a screw 58 is inserted and fixed in the long hole 59. The separation plate 56 is movable in the longitudinal direction by thermal expansion. It has become.

  A plurality of notches 60 are provided in the main body portion 56 c of the separation plate 56. Similarly to the notch 55, the notch 60 is for releasing water vapor and water droplets due to water adhering to the paper and toner. The notch 60 deforms the paper due to water vapor accumulated near the separation plate 56 and removes the paper to the separation plate 56. Image deterioration due to contact or adhesion of water vapor or water droplets can be prevented. As shown in FIG. 14, the notch 60 avoids the position where both ends of the conveyed paper travel, and is formed at other positions so that the corner of the paper is not in contact with the separation plate 56. It is possible to prevent the object from being caught in the notch 60.

  As described above, the second modification has the same effect as the first modification, but in addition to that, deformation of the paper due to water vapor accumulated near the separation plate, contact of the paper with the separation plate, and adhesion of water vapor or water droplets. It is possible to prevent image degradation caused by

Embodiment 4 FIG.
FIG. 16 is a perspective view showing a fixing device according to the fourth embodiment, FIG. 17 is a side sectional view showing the fixing device according to the fourth embodiment, and FIG. 18 is a perspective view showing a main part of the fourth embodiment. The fourth embodiment is provided with means for keeping the distance between the separation plate and the fixing roller constant.

  16 and 17, a separation plate 71 is disposed between the left side plate 2 and the right side plate 3. The separation plate 71 has an L-shaped cross section, and both end portions are movably supported by the receiving holes 72 of the left side plate 2 and the receiving holes 73 of the right side plate 3. A spring 74 is disposed inside the receiving hole 72 and biases one end of the separation plate 71 toward the fixing roller 6. A spring 75 is disposed inside the receiving hole 73 to urge the other end of the separation plate 71 toward the fixing roller 6.

  As shown in FIG. 18, a contact roller 76 is rotatably provided on one end side of the separation plate 71, and a contact roller 77 is rotatably provided on the other end side. The springs 74 and 75 urge the separation plate 71 toward the fixing roller 6, so that the contact rollers 76 and 77 are pressed against the fixing roller 6, whereby the leading end 71 a of the separation plate 71 and the fixing roller 6 The interval is kept constant. The contact rollers 76 and 77 are provided on both sides of the paper conveyance area, and the normally conveyed paper does not contact the contact rollers 76 and 77.

  A separation plate 81 is also provided on the pressure roller 7 side. The separation plate 81 has a substantially L-shaped cross section, and both end portions thereof are received in the receiving holes 82 of the left side plate 2 and the receiving holes 83 of the right side plate 3 and are movably supported. A spring 84 is disposed inside the receiving hole 82 and biases one end portion of the separation plate 81 toward the pressure roller 7. A spring 85 is disposed inside the receiving hole 83 and urges the other end of the separation blade 81 toward the pressure roller 7.

  A contact roller 86 is rotatably provided on one end side of the separation plate 81, and a contact roller 87 is rotatably provided on the other end side. The springs 84 and 85 urge the separation plate 81 in the direction of the pressure roller 7, so that the contact rollers 86 and 87 are pressed against the pressure roller 7, whereby the tip of the separation plate 81 and the pressure roller 7 are pressed. Is kept constant.

  In the fourth embodiment having the above configuration, the separation plate 71 is always pressed against the surface of the fixing roller 6 by the springs 74 and 75. As a result, the gap between the tip 71a of the separation plate 71 and the fixing roller 6 is kept constant, and a stable function can always be exhibited in the separation of the paper.

  FIG. 19 is a main part perspective view showing a modification of the fourth embodiment. FIG. 20 is a plan view of relevant parts showing a modification of the fourth embodiment. The separation plate 91 has end portions 91a and 91b, a plurality of protruding portions 91c, and a plurality of cutout portions 91d. End portions 91a and 91b of the separation plate 91 are slidably received in narrow slits provided in the left side plate 2 and the right side plate 3, and are supported so as to be movable back and forth with respect to the circumferential surface of the fixing roller. Yes. The springs 74 and 75 are provided at both ends of the separation plate 91 (only the spring 74 is shown in FIG. 19), and urge the end portions 91a and 91b of the separation plate 91 against the circumferential surface of the fixing roller 6. Yes. Since the plurality of projecting portions 91c are shorter than the end portions 91a and 91b by a distance h, only the end portions 91a and 91b abut against the circumferential surface of the fixing roller. Therefore, the separation plate 91 is positioned such that the plurality of protrusions 91c and the surface of the fixing roller 6 maintain a constant gap. Since the end portions 91a and 91b are outside the region W through which the sheet 19 to be conveyed passes, even if the fixing roller is slightly worn by friction with the fixing roller, the print quality and the sheet conveyance are affected. There is no. In addition, the plurality of notches 91d function to release water vapor and water droplets, similarly to the notches 55 in the third embodiment. The characteristics required for the material of the separation plate 91 are that it does not deform even when it receives heat from the fixing roller 6, has sufficient wear resistance against contact with the fixing roller and friction, and has low thermal expansion. And having a hardness equivalent to or lower than that of the fixing roller. Therefore, synthetic resins having excellent heat resistance and abrasion resistance are used. Specific examples of these materials include polyimide and PEEK materials (polyetheretherketone). In this modification, in addition to the same effects as in the fourth embodiment, the number of parts can be reduced by forming the separation plate 91 integrally.

1 is a perspective view illustrating a fixing device according to a first embodiment. FIG. 2 is a side sectional view showing the fixing device according to the first embodiment. 6 is an explanatory diagram illustrating a sheet separation operation according to Embodiment 1. FIG. It is a figure explaining the setting conditions of the clearance gap between a separation plate and a fixing roller. The relationship between the leading edge of the paper and the margin area is shown. FIG. 6 is a front view illustrating a fixing device according to a second embodiment. FIG. 6 is a side sectional view showing a fixing device according to a second embodiment. FIG. 6 is a front view showing a separation plate of a second embodiment. It is explanatory drawing which shows the attachment state of a separation plate. FIG. 10 is a front view illustrating a fixing device according to a third embodiment. FIG. 10 is a perspective view showing a main part of a third embodiment. FIG. 10 is an explanatory diagram showing a first modification of the third embodiment. FIG. 10 is an explanatory diagram showing a first modification of the third embodiment. FIG. 10 is an explanatory diagram showing a second modification of the third embodiment. FIG. 10 is a perspective view showing a second modification of the third embodiment. FIG. 6 is a perspective view showing a fixing device according to a fourth embodiment. FIG. 6 is a side sectional view showing a fixing device according to a fourth embodiment. FIG. 10 is a perspective view showing a main part of a fourth embodiment. FIG. 11 is a perspective view of relevant parts showing a modification of the fourth embodiment. FIG. 11 is a plan view of relevant parts showing a modification of the fourth embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Fixing device, 6 Fixing roller, 7 Pressure roller, 11, 21, 41, 51, 71, 91 Separation plate, 14, 27, 44, 56, 81 Separation plate, 19 Paper, 24 Separation plate guide, 30 Separation plate Guide, 55 notch, 60 notch, 76,77 contact roller, 86,87 contact roller.

Claims (5)

In a fixing device for fixing a toner image attached to a medium by applying heat and pressure,
A fixing member pressed against the pressure member;
A separation plate disposed close to and in parallel with the fixing member;
A frame that is located on the longitudinal direction side of the separation plate and supports the separation plate in a state having a gap with a longitudinal end of the separation plate;
Urging means for urging the longitudinal end of the separation plate in the longitudinal direction of the separation plate to allow variation in the gap between the longitudinal end and the frame ;
The separation plate includes a flat portion in which a distance between the front end facing the fixing member and the fixing member is set to a predetermined value, and a bent portion provided on the opposite side of the flat portion and the front end. A fixing device.   The fixing device according to claim 1, wherein both ends of the separation plate are in contact with the fixing member.   The fixing device according to claim 1, wherein one end of the separation plate is fixed to the frame.   The fixing device according to claim 1, wherein the bent portion of the separation plate is bent to a side opposite to a conveyance surface of the medium.   A recording apparatus comprising the fixing device according to claim 1.

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