JP2017128449A - Recording material determination device and image forming apparatus including the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a recording material determination device which inhibits a transmission member from being damaged while inhibiting a recording material from fluttering.SOLUTION: In a recording material determination device 50, including a light source 61 which irradiates a recording material P with light, an image sensor 63 which receives light irradiated by the light source 61 and reflected on a surface of the recording material P, a cover member 68 which is provided between the recording material P irradiated with the light by the light source 61 and the image sensor 63 and transmits the light reflected on the surface of the recording material P, and a roller 71 which is provided opposite to the cover member 68 and presses the recording material P toward the cover member 68, for determining the type of the recording material P irradiated with the light by the light source 61 based on an image captured by the image sensor 63, the roller 71 is a rotation member which rotates together with the recording material P conveyed on the cover member 68, and the roller 71 includes a recess 71a which does not contact an entire area of a portion corresponding to an image used to determine the recording material P and a projection 71b which contacts the recording material P.SELECTED DRAWING: Figure 9

Description

  The present invention relates to a recording material discriminating apparatus that discriminates the surface property by imaging the surface of a recording material and an image forming apparatus including the recording material discriminating apparatus.

  An electrophotographic image forming apparatus such as a copying machine or a laser printer includes an image carrier that carries a latent image, and a developing device that visualizes the latent image as a developer image by applying a developer to the image carrier. And have. The image forming apparatus further includes a transfer unit that transfers the developer image by the developing device to a recording material conveyed in a predetermined direction under a predetermined transfer condition. Further, the image forming apparatus includes a fixing device that fixes the developer image onto the recording material by heating and pressurizing the recording material on which the developer image has been transferred by the transfer unit under predetermined fixing conditions.

  Conventionally, in such an image forming apparatus, the size and type of the recording material are set by the user through a control panel of the image forming apparatus. Then, according to the setting, transfer conditions (for example, transfer bias voltage, recording material conveyance speed during transfer, etc.) and fixing conditions (for example, fixing temperature, recording material conveyance speed during fixing, etc.) are set. It is controlled.

  In recent years, it has also been proposed to use a sensor for discriminating the recording material inside the image forming apparatus to discriminate the type of the recording material and to control the transfer condition or the fixing condition according to the discrimination result. Has been.

  For example, in Patent Document 1, light is irradiated to a surface of a recording material to be detected at a relatively shallow angle (about 10 degrees to 15 degrees) to generate a shadow from unevenness on the surface of the recording material. It is described that the smoothness of the surface of the recording material can be determined with high accuracy by imaging the image of the image.

  Further, in Patent Document 2, an urging plate that faces the detection unit of the optical sensor is provided, and when the recording material to be detected is conveyed, the recording material is pressed against the detection unit of the optical sensor by the urging plate so as to be fluttered. It is described to suppress.

JP 2010-266432 A Japanese Patent No. 4447975

  However, as disclosed in Patent Document 1, light is irradiated at a relatively shallow angle (about 10 degrees to 15 degrees) with respect to the recording material surface, and a shadow is generated from the unevenness of the recording material surface. When imaging the shadow, when the recording material to be detected is conveyed, the vertical position fluctuation (flapping) of the recording material may occur more than expected. In that case, if the surface properties of the recording material cannot be captured optically with high accuracy, the recording material discrimination accuracy decreases.

  Therefore, as in Patent Document 2, it is conceivable to provide a transmissive member that transmits light on the sensor side that images the surface of the recording material, and press the recording material against the transmissive member with an urging plate to suppress fluttering. However, depending on the pressing force of the urging plate and the type of the recording material, the transmission member may be damaged due to repeated rubbing by the recording material conveyed by the transmission member.

  In this case, the sensor for imaging the surface of the recording material receives the light transmitted through the damaged transmission member, but the irregular reflection component increases due to the scratch. For this reason, there is a problem that it is impossible to accurately capture the shadow on the surface of the recording material.

  The present invention solves the above-described problems, and an object of the present invention is to provide a recording material discriminating apparatus that suppresses the scratch of the transmission member while suppressing the fluttering of the recording material.

  In order to achieve the above object, a typical configuration of the recording material discriminating apparatus according to the present invention includes a light irradiation means for irradiating the recording material with light, and a light irradiated by the light irradiation means and reflected by the surface of the recording material. An imaging unit that receives light, a recording member that is irradiated with light by the light irradiation unit and the imaging unit, a transmission member that transmits light reflected by the recording material surface, and facing the transmission member And a pressing member that presses the recording material toward the transmitting member, and determines the type of the recording material irradiated with light by the light irradiation unit based on an image captured by the imaging unit In the material discriminating apparatus, the pressing member is a rotating member that rotates together with the recording material conveyed on the transmitting member, and the pressing member is disposed over the entire area corresponding to the image used for the discrimination of the recording material. Non-contact Characterized in that it comprises a region, a contact region in contact with the recording material, the.

  According to the above configuration, the transmissive member is scratched by the non-contact area that does not contact the entire region corresponding to the image used for discrimination of the recording material while suppressing the flutter of the recording material by the contact area that contacts the recording material. Sticking can be suppressed.

1 is an explanatory cross-sectional view illustrating a configuration of an image forming apparatus including a recording material discrimination device according to the present invention. It is a perspective explanatory view showing a configuration of an optical system of the recording material discrimination device. It is a disassembled perspective view which shows the structure of the optical system of a recording material discrimination | determination apparatus. (A) is a perspective view explaining the arrangement configuration of the optical components of the recording material discrimination device, (b) is a plan view, a side view, and a front view explaining the arrangement configuration of the optical components of the recording material discrimination device. (A) is a perspective explanatory view showing a configuration of a comparative example of the recording material discriminating device, (b) is a perspective explanatory view showing a state in which the recording material is conveyed between the transmitting member and the pressing member. (A) is front explanatory drawing which shows the structure of the principal part of the comparative example of a recording material discrimination | determination apparatus, (b) is HH sectional drawing of (a). It is a figure which shows the recording material displacement amount at the time of recording material conveyance in the recording material discrimination apparatus of a comparative example. (A) is a perspective view explaining the subject in the recording material discrimination device of a comparative example. (B) is a perspective view showing a state in which the transmission member of the recording material discriminating apparatus of the comparative example is scratched. (A) is a perspective explanatory view showing the configuration of the first embodiment of the recording material discriminating apparatus according to the present invention, and (b) is the recording material between the transmission member and the pressing member of the recording material discriminating apparatus of the first embodiment. It is perspective explanatory drawing which shows a mode that is conveyed. (A) is front explanatory drawing which shows the structure of the principal part of the recording material discrimination apparatus of 1st Embodiment, (b) is sectional explanatory drawing which shows the structure of the principal part of the recording material discrimination apparatus of 1st Embodiment. It is a figure which shows the recording material displacement amount at the time of recording material conveyance in the recording material discrimination | determination apparatus of 1st Embodiment. FIG. 3A is a perspective view showing a state in which a scratch is attached outside an image area used for discrimination of a recording material of a transmission member of the recording material discrimination apparatus of the first embodiment. (B), (c) is a perspective view showing a state in which a scratch is attached outside an image region used for discrimination of the recording material of the transmission member of the recording material discrimination apparatus of the first embodiment. (A) is perspective explanatory drawing which shows the structure of 2nd Embodiment of the recording material discrimination | determination apparatus based on this invention, (b) is front explanatory drawing which shows the structure of the press member of 2nd Embodiment. It is a figure which shows the recording material displacement amount at the time of recording material conveyance in the recording material discrimination apparatus of 2nd Embodiment. (A) is a perspective explanatory drawing which shows the structure of 3rd Embodiment of the recording material discrimination | determination apparatus based on this invention, (b) is front explanatory drawing which shows the structure of the press member of 3rd Embodiment. It is a perspective explanatory view showing a configuration of a recording material discrimination device according to the present invention. (A) is front explanatory drawing which shows the structure of the press member of 4th Embodiment, (b) is side explanatory drawing which shows the structure of the press member of 4th Embodiment, (c) is AA cross section of (a). FIG. 4D is a sectional view taken along line BB in FIG. (A), (b) is sectional explanatory drawing which shows a mode that the contact member of 4th Embodiment moves to the direction which presses a recording material toward a transmission member to a press member.

  An embodiment of a recording material discriminating apparatus according to the present invention and an image forming apparatus having the same will be described in detail with reference to the drawings.

  First, the configuration of the first embodiment of the recording material discriminating apparatus according to the present invention and the image forming apparatus including the same will be described with reference to FIGS.

  The recording material discriminating apparatus 50 according to the present embodiment can be used in, for example, an electrophotographic color image forming apparatus 3. FIG. 1 shows a tandem color image forming apparatus that employs an intermediate transfer belt 24 as an example. 3 is shown.

<Image forming apparatus>
First, the configuration and operation of the image forming unit of the image forming apparatus 3 used in this embodiment will be described with reference to FIG.

  The image forming unit serving as an image forming unit that forms a toner image on the recording material P forms a toner image for each station of the feeding cassette 15 serving as a feeding unit, yellow Y, magenta M, cyan C, and black Bk. The photosensitive drums 1Y, 1M, 1C, and 1Bk serving as image bearing members are provided.

  Further, it has charging rollers 2Y, 2M, 2C and 2Bk as primary charging means, exposure light scanner sections 11Y, 11M, 11C and 11Bk, and developing devices 8Y, 8M, 8C and 8Bk as developing means. Further, the image forming apparatus includes an intermediate transfer belt 24 serving as an image carrier on which a toner image is formed, a driving roller 23 that drives the intermediate transfer belt 24, a stretching roller 13, and a secondary transfer counter roller 26.

  Further, the image forming apparatus includes primary transfer rollers 4Y, 4M, 4C, and 4Bk, and a secondary transfer roller 25 that serves as a transfer unit that transfers the toner image formed on the intermediate transfer belt 24 to the recording material P. Further, the image forming apparatus includes a fixing unit 21 serving as an image fixing unit that heats and presses and fixes a toner image formed on the recording material P (on the recording material), and a control unit 10 serving as a control unit that controls the toner image. Configured.

  For convenience of explanation, the photosensitive drums 1Y, 1M, 1C, and 1Bk may be described as the photosensitive drum 1 as a representative. Other image forming units will be described in the same manner.

  The photosensitive drums 1Y, 1M, 1C, and 1Bk are configured by applying an organic optical transmission layer to the outer periphery of an aluminum cylinder, and rotate by receiving a driving force of a driving motor (not shown). The drive motor rotates the photosensitive drums 1Y, 1M, 1C, and 1Bk in the clockwise direction of FIG. 1 according to the image forming operation.

  When the control unit 10 receives the image signal, the recording material P is fed into the image forming apparatus 3 by the feed rollers 17 and 18 from the feed cassette 15 or the like. Then, it is once sandwiched between registration rollers 19 serving as a roller-like synchronous rotating body for synchronizing the image forming operation described later and the conveyance of the recording material P, and stops and waits.

  On the other hand, in accordance with the received image signal, the control unit 10 has the photosensitive drums 1Y, 1M, 1M, 11M, 11C, and 11Bk charged to a constant potential by the action of the charging rollers 2Y, 2M, 2C, and 2Bk. An electrostatic latent image is formed on the surface of 1C and 1Bk.

  Here, the developing devices 8Y, 8M, 8C, and 8Bk are means for supplying toner to the electrostatic latent image formed on the surface of the photosensitive drum 1 to visualize it as a toner image. Yellow Y and magenta M are provided for each station. , Cyan C, and black Bk are developed. Each developing device 8 is provided with developing sleeves 5Y, 5M, 5C, and 5Bk, and a developing bias voltage for visualizing the electrostatic latent image is applied to the developing sleeve 5.

  As described above, the electrostatic latent images formed on the surfaces of the photosensitive drums 1Y, 1M, 1C, and 1Bk are developed as single-color toner images by the action of the developing devices 8Y, 8M, 8C, and 8Bk.

  Each of the photosensitive drum 1, the charging roller 2, and the developing device 8 is integrally configured, and is attached in the form of a toner cartridge 31 that is detachable from the main body of the image forming apparatus 3.

  The intermediate transfer belt 24 is in contact with the surface of the photosensitive drums 1Y, 1M, 1C, and 1Bk so as to be able to contact and separate, and rotates the photosensitive drums 1Y, 1M, 1C, and 1Bk in the counterclockwise direction in FIG. Rotate in sync with The single color toner image developed on the surface of each photosensitive drum 1 is sequentially transferred onto the outer peripheral surface of the intermediate transfer belt 24 by the action of the primary transfer bias voltage applied to the primary transfer roller 4, and on the intermediate transfer belt 24. A multicolor toner image is obtained.

  Thereafter, the multicolor toner image formed on the intermediate transfer belt 24 is conveyed to a secondary transfer nip portion formed by the secondary transfer roller 25. At the same time, the recording material P that has been waiting while being held between the registration rollers 19 is conveyed to the secondary transfer nip portion while being synchronized with the multicolor toner image on the intermediate transfer belt 24 by the action of the registration rollers 19. The Then, the multicolor toner image on the intermediate transfer belt 24 is collectively transferred onto the recording material P by the action of the secondary transfer bias voltage applied to the secondary transfer roller 25.

  The fixing unit 21 melts and fixes the transferred multi-color toner image while conveying the recording material P, and as shown in FIG. 1, the fixing roller 21a for heating the recording material P and the recording material P are fixed to the fixing roller. A pressure roller 21b is provided for pressure contact with 21a.

  The fixing roller 21a and the pressure roller 21b are formed in a hollow shape, and heaters 21ah and 21bh are incorporated therein, respectively.

  The recording material P holding the multicolor toner image is conveyed by the fixing roller 21a and the pressure roller 21b, and heat and pressure are applied to fix the toner on the surface of the recording material P.

  The recording material P after the toner image is fixed is discharged to the discharge tray 16 by the discharge roller 20, and the image forming operation is completed.

  A cleaning blade 28 serving as a cleaning unit cleans toner remaining as a transfer residue on the intermediate transfer belt 24, and the transfer residual toner collected here is stored in a waste toner container 29 as waste toner.

  Such a series of image forming operations is controlled by the control unit 10 provided in the image forming apparatus 3.

  In the image forming apparatus 3 shown in FIG. 1, the recording material determination device 50 of the present embodiment is installed in a recording material determination unit provided near the downstream side of the registration roller 19 on the recording material conveyance path. Information reflecting the surface smoothness of the recording material P fed from the feeding cassette 15 is detected by the recording material discrimination device 50. In the present embodiment, the surface smoothness of the recording material P by the recording material determination device 50 is determined while the recording material P is fed from the feeding cassette 15 into the image forming apparatus 3 and is nipped and conveyed by the registration rollers 19. Done.

  Based on the discrimination information (discrimination result) of the recording material P sent from the recording material discrimination device 50, the control unit 10 determines the optimum image forming conditions of the image forming means and controls the image forming apparatus 3. Further, the image forming apparatus 3 is controlled to operate by determining an optimum transfer bias voltage as a transfer condition of the secondary transfer roller 25 as a transfer unit. Further, the image forming apparatus 3 is controlled to operate by determining an optimum fixing temperature or the like as a fixing condition of the fixing unit 21 as a fixing unit.

<Recording material discrimination device>
Next, the configuration of the recording material determination device 50 of the present embodiment will be described.

<Comparative example and its problems>
First, the configuration of the comparative example and its problem will be described with reference to FIGS. FIG. 2 is an overall perspective view of a single recording material discriminating apparatus 50. The recording material determination device 50 includes an upper lid member 51 and a housing member 52.

  FIG. 3 is an exploded perspective view of the recording material discrimination device 50. As shown in FIG. 3, two light sources 61R and 61L serve as light irradiating means for irradiating the recording material P with light from different directions installed on a substrate 65 provided below the housing member 52, as shown in FIG. Light is illuminated toward the recording material P shown. The light sources 61R and 61L of the present embodiment are configured by chip-mounted LEDs (Light Emitting Diodes).

  At this time, the irradiation directions of the optical axes 66R1 and 66L1 irradiated by the light sources 61R and 61L are set to the optical axes 66R2 and 66L2 in the recording material discriminating device 50 by the polarizers 64R and 64L, as shown in FIG. Thus, the optical path is polarized. A cover member 68, which is installed on the upper cover member 51, supports the recording material P and guides conveyance, and serves as a transparent transmission member formed of glass or the like that also serves to prevent dust from entering from the outside. The light is transmitted and guided to the surface of the recording material P shown in FIG.

  The cover member 68 serving as a transmission member includes a recording material P irradiated with light by the light sources 61R and 61L, and a linear imaging element serving as an imaging unit that receives light reflected by the surface of the recording material P (the recording material surface). The light reflected by the surface of the recording material P (recording material surface) is transmitted.

  The surface of the recording material P is irradiated through the transparent cover member 68 by the optical axes 66R2 and 66L2 guided by the polarizers 64R and 64L. As a result, the surface property of the recording material P (unevenness caused by the fibers of the paper recording material P) can be detected as light brightness (shadow). Then, the surface property of the recording material P is converted into a light / dark distribution of light through a condensing element 62 formed of a rod lens by a line-shaped imaging element 63 in which a plurality of light receiving pixels arranged in a line are arranged on the substrate 65. Imaged.

  From the obtained image reflecting the surface properties of the recording material P, an optical feature amount such as contrast is extracted and calculated, and the surface property of the recording material P is judged based on the value (type of the recording material P). Can be determined).

  In this embodiment, as shown in FIG. 4B, the polarizer 64R is supplied from the two light sources 61R and 61L so that the surface property of the recording material P can be discriminated irrespective of the fiber orientation direction of the paper recording material P. , 64L is irradiated from two directions toward the surface of the recording material P.

  4A, for convenience of explanation, the top cover member 51 and the housing member 52 are omitted, and the three-dimensional arrangement configuration of each component such as the light sources 61R and 61L and the polarizers 64R and 64L is omitted. It is a perspective view shown. Note that the same parts arranged symmetrically may be described with the subscripts R and L omitted for convenience of description.

  FIG. 4B shows a state including an optical path and the like in a three-view diagram. Lights 66L1, 66R1, 66L2, and 66R2 that are guided from the light source 61 to the polarizer 64, pass through the cover member 68, and become virtual center lines of the optical path to the observation image center T that coincides with the surface of the recording material P, respectively. Indicated by a two-dot chain line.

  A virtual optical axis is shown with the observation image center T as the optical center, and at the same time, an effective irradiation area E on the surface of the recording material P (the surface of the cover member 68) is indicated by an elliptical broken line in FIG. . At this time, as shown in FIG. 4B, the optical axes 66R2 and 66L2 have an inclination θ with respect to the conveyance direction of the recording material P (the Y-axis direction in FIG. 4B).

  Further, a typical state passing through the respective observation image centers T in the left and right effective irradiation areas E on the cover member 68 is indicated by virtual optical axes 66R3 and 66L3 in FIG. One line including the observation image center T in the effective irradiation area E on the surface of the cover member (the surface of the recording material P) is imaged in a line shape by the line-shaped image sensor 63 via the light collecting element 62.

Here, the arrangement reference coordinates of each component will be described using the X axis, the Y axis, and the Z axis shown in FIG. In FIG. 4B, the Y axis indicates the optical axis of symmetry and the conveyance direction of the recording material P. The X axis on the image sensor 63 indicates a direction orthogonal to the conveyance direction of the recording material P. The Z axis indicates the thickness direction of the recording material P. When discriminating the recording material P, image portions corresponding to the portions of the effective irradiation areas E _R and E _L of the recording material P are used in the X-axis direction among the images picked up by the image pickup device 63.

That is, an optical feature amount such as contrast is extracted and calculated for the image portion corresponding to the effective irradiation areas E _R and E _L of the recording material P, and the surface property of the recording material P is determined based on the value. (The type of the recording material P is determined).

  It is desirable to press the recording material P onto the surface of the cover member 68 so that the recording material discriminating apparatus 50 having such an optical system can be observed with high accuracy. By moving the recording material P while pressing the recording material P against the flat portion of the surface of the cover member 68 with a predetermined force, it is possible to set the position variation of the surface of the recording material P within the depth allowed by the optical system. I can do it.

  These aspects will be described with reference to comparative examples shown in FIGS. FIG. 5A shows a state in which a cylindrical roller 70 is installed as a pressing member so as to face the cover member 68 provided on the upper surface of the recording material discrimination device 50. FIG. 5B shows a state where the recording material P is conveyed while being sandwiched between the roller 70 and the cover member 68 by showing a part of the recording material P. The arrow a direction in FIG. 5B indicates the conveyance direction of the recording material P. The direction of arrow F in FIG. 5B indicates the direction of the pressing force with which the roller 70 presses the recording material P toward the cover member 68.

  FIG. 6 shows a state in which the roller 70 presses the recording material P toward the cover member 68 and the arrangement relationship between the cover member 68 and the recording material P is viewed from the upstream side in the conveyance direction of the recording material P. Indicates. As shown in FIG. 6A, a pressing force F is applied to both ends of the rotation shaft 70a of the roller 70 from the vertical direction (above FIG. 6A), whereby the recording material P is placed on the cover member 68. Can be seen to be held in a straight line.

  Moreover, the HH cross section in Fig.6 (a) is shown in FIG.6 (b). FIG. 6B shows the conveyance direction of the recording material P in the direction of arrow a, and the rotation direction of the roller 70 in the direction of arrow b. When the recording material P is conveyed and moved in the left direction of FIG. 6B, the roller 70 is driven to rotate in the direction of the arrow b while pressing the recording material P, and the recording material P is rubbed on the cover member 68. Move.

  With such a configuration, it is possible to reduce the fluctuation amount of the surface of the cover member 68 of the recording material P when the recording material P is conveyed. FIG. 7 shows an example of the result of measuring the amount of fluctuation of the surface of the recording material P from the surface of the cover member 68 using a laser displacement meter. The horizontal axis of FIG. 7 shows time (sec), and a vertical axis | shaft shows fluctuation amount (displacement; mm). One scale on the vertical axis represents 100 μm. As shown in FIG. 7, it can be seen that the surface of the recording material P changes with a fluctuation amount (displacement) of 100 μm or less represented by one scale on the vertical axis.

  However, when a large number of various recording materials P are conveyed while pressing the recording material P using the rollers 70, the recording material P and the surface of the cover member 68 are rubbed. For this reason, as shown in FIG. 8, scratches D are generated on the surface of the cover member 68. FIG. 8A shows an overall view of the recording material discriminating apparatus 50 in which the scratch D has occurred on the surface of the cover member 68. FIG. FIG. 8B shows a single structure of the cover member 68 with the scratch D.

  As shown in FIG. 8B, it can be observed that the scratches D are distributed linearly in the longitudinal direction (lateral width direction) on the surface of the cover member 68. By pressing the recording material P against the surface of the cover member 68 by the roller 70, the amount of fluctuation of the surface of the recording material P was reduced. However, as a result of long-term use, innumerable fine scratches such as scratches D were generated on the surface of the cover member 68 along the pressing nip portion of the roller 70 on the surface of the cover member 68.

  When the surface of the recording material P is observed at the nip portion of the recording material P and the surface property of the recording material P is judged, the scratch D generated on the surface of the cover member 68 induces a diffuse reflection component to the optical observation system. Then, a noise component due to a decrease in light amount and optical factors is generated. For this reason, it is difficult to obtain the expected surface observation data of the recording material P, and the problem that the discrimination accuracy of the recording material P is reduced occurs.

  As a countermeasure against this problem, it is considered that the scratch D is hardly generated if the pressing force F by the roller 70 is simply reduced. However, the fluctuation amount of the recording material P cannot be suppressed.

  Further, in order not to make the nip portion of the roller 70 that is the pressing portion of the roller 70 that causes the abrasion D to coincide with the detection portion by the optical system, the nip portion of the roller 70 is offset to the upstream and downstream in the conveyance direction of the recording material P. If you want to. However, since the length of the recording material P in the transport direction of the scratch D is several mm or more, it is necessary to offset a distance of several mm or more from the detection region of the optical system. In such a configuration, the pressure restraining force of the recording material P cannot be reduced, and it becomes difficult to stably observe the surface of the recording material P.

  In order to solve the problem of the comparative example shown in FIGS.

  FIG. 9A shows the cover member 68 (on the transmission member) as a pressing member that presses the recording material P toward the cover member 68 so as to face the cover member 68 serving as the transmission member of the recording material discrimination device 50. A roller 71 is provided as a rotating member that rotates together with the recording material P that is conveyed in step S1.

  The recording material discriminating device 50 discriminates the type of the recording material P irradiated with light from the light source 61 based on the image captured by the image sensor 63. A central portion in the axial direction of the cylindrical portion of the roller 71 is provided with a concave portion 71a serving as a non-contact region that does not contact the entire region corresponding to the image used for discrimination of the recording material P. In addition, with respect to a direction orthogonal to the conveyance direction of the recording material P, convex portions 71b serving as contact regions in contact with the recording material P are provided on both sides of the concave portion 71a serving as a non-contact region of the roller 71.

  FIG. 9B shows a state in which the recording material P is nipped and conveyed between the cover member 68 in a state where the pressing force F is applied to the roller 71 and the load is urged to the recording material P. 10A and 10B show an installation state using only the optical system and the roller 71. FIG. As shown in FIG. 10A, a state in which the recording material P is sandwiched and contacted by the convex portions 71b and the cover member 68 serving as contact areas provided on both sides of the cylindrical portion of the roller 71 is shown.

  A recess 71a that is a non-contact area of the roller 71 indicates a state in which the recording material P is not sandwiched and is not in contact. As shown in FIG. 10B, there is a predetermined gap G between the outer peripheral surface of the recess 71a that is a non-contact area of the roller 71 and the surface of the cover member 68.

  FIG. 11 shows the amount of fluctuation of the surface of the recording material P in this embodiment. In FIG. 11, the horizontal axis indicates time (sec), and the vertical axis indicates the amount of displacement (displacement). One scale on the vertical axis is 100 μm.

  By providing the recess 71a that is a non-contact region of the roller 71, the pressing restraining force on the recording material P is reduced. As a result, the surface of the recording material P slightly varies compared to the amount of variation of the surface of the recording material P in the comparative example shown in FIG. However, as shown in FIG. 11, even in this embodiment, the fluctuation amount allowed by the depth of the optical system is 100 μm or less. Thereby, it can be seen that the recording material discriminating apparatus 50 of the present embodiment has sufficient accuracy to observe the surface property of the recording material P and discriminate the type of the recording material P.

Furthermore, FIG. 12 shows the state of the surface of the cover member 68 when a large variety of recording materials P are nipped and conveyed using the roller 71 having the recess 71a as in the present embodiment. FIG. 12A is a perspective view showing an overview of the entire recording material discriminating apparatus 50. FIG. FIG. 12B is an enlarged perspective view showing only the cover member 68. FIG. 12C shows the effective irradiation areas E _R and E _L corresponding to the image used for discrimination of the recording material P shown in FIG. 4 by broken lines.

With respect to the X-axis direction shown in FIG. 4, in the present embodiment, as shown in FIG. 12, at the position corresponding to the concave portion 71a including the entire effective irradiation regions E _R and E _L of the roller 71 on the surface of the cover member 68, The scratch D of the recording material P was not observed.

  Further, at the place where the recording material P other than the concave portion 71a of the roller 71 was pressed, the same scratch D as in the comparative example occurred. As described above, even after the recording material P is conveyed in a large amount, no scratch D is generated at the position corresponding to the recess 71a of the roller 71 on the surface of the cover member 68, and the surface of the cover member 68 is not changed. . Thereby, the irradiation observation state of the surface of the recording material P is maintained in the initial state. Therefore, in this embodiment, a good observation state is maintained before and after the conveyance of a large amount of recording material P.

  This indicates that the discrimination accuracy of the recording material P in the initial stage can be maintained for a long period of time, and the discrimination accuracy based on the irregular reflection component due to the scratch D on the surface of the cover member 68 while minimizing the surface fluctuation of the recording material P. A configuration that does not cause a drop was realized.

  As described above, the moving recording material P is irradiated with light from two directions, and the surface properties of the recording material P are observed to determine the type of the recording material P. At that time, in order to keep the surface fluctuation of the recording material P within the optical measurement guarantee range, a roller 71 that presses the recording material P against the observation surface is used. By providing the recess 71a in a part of the roller 71, it is possible to maintain the observation performance of the surface property of the recording material P for a long time regardless of the large amount of various recording materials P being conveyed. Thereby, it is possible to guarantee the discrimination accuracy of the recording material P. Further, the recording material discriminating apparatus 50 of the present embodiment can be configured to be small and inexpensive, and an apparatus having a discriminating accuracy of the recording material P can be realized.

  In this embodiment, the surface-mount type LED is used as the light source 61. However, if the recording material P can be illuminated from two directions with respect to the transport direction under a predetermined condition, a bullet-type LED is used. It may be adopted. Other illumination means may be used.

  In addition, the illumination light from the light source 61 was guided to the surface of the recording material P using a light guide such as a polarizer 64, but the light path was set and a reflector or the like was used without using the light guide. A light guide may be set.

  Next, the configuration of the second embodiment of the image forming apparatus provided with the recording material discrimination apparatus according to the present invention will be described with reference to FIGS. In addition, what was comprised similarly to the said 1st Embodiment attaches | subjects the same code | symbol, and abbreviate | omits description.

  In the present embodiment, two light sources 61R and 61L for irradiating the recording material P with light from different directions are provided as light irradiating means. The roller 72, which is a pressing member and is a rotating member, includes two recesses 72a1 and 72a2 that are two non-contact areas corresponding to the portions of the recording material P irradiated with the two light sources 61R and 61L, respectively.

  With respect to the direction orthogonal to the conveyance direction of the recording material P (the axial direction of the roller 72), convex portions 72b1 serving as contact regions are provided between the concave portions 72a1 and 72a2 serving as non-contact regions, and further on both sides of the concave portions 72a1 and 72a2. Protrusions 72b2 and 72b3 serving as contact areas are provided.

  FIG. 13A is a perspective explanatory view showing a roller 72 that is a pressing member that presses the recording material P against the cover member 68 of the recording material discriminating device 50 and that serves as a rotating member. In the present embodiment, a convex portion 72b1 serving as a contact region in contact with the recording material P is further added between the concave portions 72a1 and 72a2 serving as non-contact regions provided on the roller 72.

There are a wide variety of recording materials P, and the main body of the image forming apparatus 3 is also used in various environments. It cannot be completely guaranteed that the recording material P is reliably and stably conveyed within the range of the recess 71a of the roller 71 of the first embodiment. As described above, in the recording material discriminating device 50, the effective irradiation areas E _R and E _L for discriminating the recording material P are set on both sides in the recess 71a installed on the cylindrical roller 71.

On the other hand, the position between the effective irradiation areas E _R and E _L set on the contrary is not involved in the measurement for discriminating the recording material P. Therefore, a convex portion 72b1 is added to a portion which is not relevant for detecting and discriminating the recording material P, and pressing portions of the recording material P are provided on both sides of the concave portions 72a1 and 72a2 and in the middle thereof, thereby stabilizing the recording material P. Can be realized.

  FIG. 14 shows a measurement example of the amount of displacement of the surface during conveyance of the recording material P when this embodiment is used. The horizontal axis in FIG. 14 indicates time (sec), and the vertical axis indicates the displacement (mm). One scale on the vertical axis is 100 μm.

  As shown in FIG. 14, in this embodiment as well, although there are some variations compared to the comparative example shown in FIG. 7, a variation of 100 μm or less, which is sufficiently allowed by the depth of the optical system, is realized. Thus, it can be seen that the state is sufficient for observing the surface property of the recording material P and determining the type of the recording material P.

  In the present embodiment, it is possible to further suppress the fluctuation amount at the time of conveyance of the recording material P by adding the convex portion 72b1 which becomes the pressing portion of the recording material P to the maximum without affecting the measurement. . That is, it is possible to ensure robustness, which is a mechanism for internally preventing changes due to external factors such as various recording materials P and use environments of the image forming apparatus 3. Other configurations are the same as those in the first embodiment, and the same effects can be obtained.

  Next, the configuration of the third embodiment of the image forming apparatus provided with the recording material discrimination device according to the present invention will be described with reference to FIG. In addition, what was comprised similarly to each said embodiment attaches | subjects the same code | symbol, and abbreviate | omits description.

  FIG. 15A shows a roller 74 which is provided facing the cover member 68 of the recording material discriminating apparatus 50 and presses the recording material P toward the cover member 68 and serves as a rotating member. .

  The roller 74 according to the present embodiment has both end portions 75 serving as contact areas that come into contact with the recording material P in a linear shape by a hard member having a Rockwell hardness of 80 to 120. In addition, a soft member having Asker C hardness of 10 to 30 or rubber hardness of 10 to 30 is provided to have a central portion 76 that is a contact region that elastically contacts the recording material P.

  In this embodiment, a new pressing member (central portion 76) is added to the recess 71a with respect to the roller 71 having the recess 71a shown in the first embodiment shown in FIG.

  There are a wide variety of recording materials P, and the main body of the image forming apparatus 3 is also used in various environments. Therefore, it cannot be completely guaranteed that the recording material P is reliably and stably conveyed within the range of the recess 71a of the roller 71 of the first embodiment. As described above, installing a means for positively pressing and urging the cover member 68 may induce damage to the surface of the cover member 68.

  As a countermeasure, in the first embodiment, a recess 71a is provided on a part of the outer peripheral surface of the roller 71 which is a pressing member. In the present embodiment, the configuration of the cylindrical roller 74 is divided into two at the both end portions 75 and the central portion 76.

  At a portion where the cover member 68 is allowed to be damaged, both ends 75 are formed of a relatively hard material such as a resin member as a main body of the roller 74 to positively press the recording material P. The amount of displacement of the recording material P is suppressed.

  On the other hand, the central portion 76 is formed of a relatively soft material such as so-called rubber or sponge at the central portion 76 where the cover member 68 is not desired to be damaged. Although such a soft member elastically presses and supports the recording material P from the back to some extent, it is not actively biased and pressed. Thereby, damage to the cover member 68 is suppressed while suppressing the amount of displacement of the surface of the recording material P.

  Since the central portion 76 made of a soft member is not a complete space, a slight pressing force is generated, but the cover member 68 is included in the number of transported recording materials P set in consideration of the life of the image forming apparatus 3. The present embodiment can be adopted as long as the scratch D is within the allowable range.

  In the present embodiment, the hardness at the pressing portion of the recording material P is appropriately changed to set the central portion 76 as a soft separate body, thereby suppressing the amount of fluctuation during conveyance of the recording material P and the cover member 68. It becomes possible to suppress damage to the skin. Other configurations are the same as those in the above embodiments, and the same effects can be obtained.

  Next, the configuration of the fourth embodiment of the image forming apparatus provided with the recording material discrimination apparatus according to the present invention will be described with reference to FIGS. In addition, what was comprised similarly to each said embodiment attaches | subjects the same code | symbol, and abbreviate | omits description.

  FIG. 16A shows a roller 77 that is a pressing member that presses the recording material P against the cover member 68 of the recording material discriminating device 50 and that serves as a rotating member. The roller 77 is provided to face a non-contact area that does not contact the entire region corresponding to the image used for discrimination of the recording material P, and corresponds to the image used for discrimination of the recording material P of the roller 77. A cylindrical member 80 serving as a contact member that can contact a portion to be touched is provided. The cylindrical member 80 is configured to be movable independently of the roller 77 in the direction in which the roller 77 presses the recording material P toward the cover member 68.

  In this embodiment, the configuration of the roller portion is changed with respect to the roller 71 having the recess 71a of the first embodiment shown in FIG. 9, and a cylindrical member 80 capable of restraining the recording material P is added to the recess 71a. is there.

  There are a wide variety of recording materials P, and the main body of the image forming apparatus 3 is also used in various environments. Therefore, it cannot be completely guaranteed that the recording material P is reliably and stably conveyed within the range of the recess 71a of the roller 71 shown in the first embodiment of FIG. As described above, installing the urging means that positively presses the cover member 68 may induce damage to the surface of the cover member 68.

  Therefore, in the present embodiment, an example of another configuration of the cylindrical roller 77 is shown. 17 (a) is a front view showing the overall configuration of the roller 77, FIG. 17 (b) is a side view, FIG. 17 (c) is a cross-sectional view taken along line AA in FIG. 17 (a), and FIG. 17 (b) is a cross-sectional view along BB.

  As shown in FIG. 17, the main body portion of the roller 77 includes a shaft member 78 and pressing portions 79R and 79L that press the recording material P. A cylindrical member 80 that can contact the recording material P and restrains the recording material P between the pressing portions 79R and 79L that press the recording material P in the axial direction of the shaft member 78 is attached to the shaft member 78. Insert and install freely. The tubular member 80 is held rotatably with respect to the shaft member 78 while having a predetermined gap G with respect to the shaft member 78.

  That is, the cylindrical member 80 can move independently of the main body of the roller 77 in the direction in which the main body of the roller 77 presses the recording material P toward the cover member 68. FIG. 18A shows a gap G between the outer peripheral surface of the shaft member 78 and the inner peripheral surface of the cylindrical member 80 in a state where the axial center of the shaft member 78 and the axial center of the cylindrical member 80 coincide. It shows how it was formed.

  In FIG. 18A, the gap G is shown to be formed uniformly around the shaft member 78, but in reality, the gap G is biased in any direction due to the influence of gravity or the like. Further, when the recording material P enters between the roller 77 and the cover member 68, as shown in FIG. 18 (b), the cylindrical member 80 is rotated while the recording material P is conveyed and the recording material P is conveyed. Contact P. Then, the main body of the roller 77 moves in the direction opposite to the direction in which the recording material P is pressed toward the cover member 68 (upward in FIG. 18B).

  Then, the lower gap G in FIG. 18B is eliminated, and a state of having a maximum gap of “2 × G” is provided on the upper side. While the recording material P is being transported, the deformation of the recording material P during transportation is restrained relatively gently under the influence of the weight of the cylindrical member 80 and the like while the surface fluctuation of the recording material P is small. If the shaft member 78 and the cylindrical member 80 having higher rigidity than the recording material P are reached until the maximum displacement of the gap G between the cylindrical member 80 and the shaft member 78 is reached, A state in which no further deformation is allowed can be realized.

During the normal conveyance of the recording material P, the cylindrical member 80 moves to about the fluctuation amount equal to or less than the gap G while rotating, and the fluctuation amount during the conveyance of the recording material P is maintained relatively gently. At this time, since the force with which the recording material P presses the surface of the cover member 68 is slight, the effective irradiation areas E _R and E _L in the cover member 68 are not scratched.

  In the present embodiment, a cylindrical member 80 that gently restrains the fluctuation amount of the recording material P is added to the roller 77, thereby suppressing the fluctuation amount during conveyance of the recording material P and damaging the cover member 68. Can be suppressed. Other configurations are the same as those in the above embodiments, and the same effects can be obtained.

P: Recording material
50 ... Recording material discrimination device
61, 61R, 61L ... Light source (light irradiation means)
63. Imaging element (imaging means)
68… Cover member (transparent member)
71 ... Roller (pressing member; rotating member)
71a ... recess (non-contact area)
71b ... convex portion (contact area)

Typical configuration of an image forming apparatus according to the present invention for achieving the above object, a morphism irradiation you irradiates light to the recording material means, is illuminated by front KiTeru elevation means, the light reflected by the recording material imaging means for imaging a surface image, before provided between the imaging means and the recording material irradiated with light by KiTeru elevation means, a transmitting member which light reflected by the recording material passes, to the transmission member a counter member provided opposite to an image forming means for forming an image on a recording material, on the basis of the surface image captured by the imaging means, and control means for controlling an image forming condition of said image forming means In the image forming apparatus, the recording material is sandwiched between the transmission member and the opposing member, so that a contact area where the opposing member contacts the recording material and a non-contact area where the opposing member does not contact the recording material are provided. Above Formed in the direction member, the non-contact region portion the entire used to control the image forming conditions of the surface image is characterized that you correspond.

Claims (8)

Light irradiating means for irradiating light to the recording material, imaging means for receiving light irradiated by the light irradiating means and reflected by the surface of the recording material, recording material irradiated with light by the light irradiating means, and the imaging means And a transmissive member that transmits light reflected by the surface of the recording material, and a pressing member that is provided facing the transmissive member and presses the recording material toward the transmissive member, In the recording material determination apparatus for determining the type of the recording material irradiated with light by the light irradiation unit based on the image captured by the imaging unit,
The pressing member is a rotating member that rotates together with the recording material conveyed on the transmitting member,
The pressing member includes a non-contact area that does not contact the entire area corresponding to the image used for the determination of the recording material, and a contact area that contacts the recording material. .   The recording material determination apparatus according to claim 1, wherein the contact areas are provided on both sides of the non-contact area with respect to a direction orthogonal to the conveyance direction of the recording material.   The light irradiating means includes two light sources that irradiate the recording material with light from different directions, and the pressing member includes two non-contact areas corresponding to portions irradiated to the two light sources of the recording material, respectively. The recording material discriminating apparatus according to claim 1, further comprising: Light irradiating means for irradiating light to the recording material, imaging means for receiving light irradiated by the light irradiating means and reflected by the surface of the recording material, recording material irradiated with light by the light irradiating means, and the imaging means And a transmissive member that transmits light reflected by the surface of the recording material, and a pressing member that is provided facing the transmissive member and presses the recording material toward the transmissive member, In the recording material determination apparatus for determining the type of the recording material irradiated with light by the light irradiation unit based on the image captured by the imaging unit,
The pressing member is a rotating member that rotates together with the recording material conveyed on the transmitting member,
The pressing member is in contact with the recording material in a linear manner by a hard member having a Rockwell hardness of 80 to 120 and elastically in contact with the recording material by a soft member having an Asker C hardness of 10 to 30 or a rubber hardness of 10 to 30. And a contact area for recording material. Provided in opposition to a non-contact area that does not contact the entire area corresponding to the image used for the determination of the recording material of the pressing member, and is used for the determination of the recording material of the pressing member. A contact member capable of contacting a portion corresponding to an image;
The recording material determination device according to claim 1, wherein the contact member is movable independently of the pressing member in a direction in which the pressing member presses the recording material toward the transmission member. . The recording material discriminating device according to any one of claims 1 to 5,
Image forming means for forming a toner image on a recording material;
Have
An image forming apparatus, wherein an image forming condition of the image forming unit is determined according to a determination result by the recording material determining apparatus. The recording material discriminating device according to any one of claims 1 to 5,
An image carrier on which a toner image is formed;
Transfer means for transferring the toner image formed on the image carrier to a recording material;
Have
An image forming apparatus, wherein a transfer condition of the transfer unit is determined according to a determination result by the recording material determination apparatus. The recording material discriminating device according to any one of claims 1 to 5,
Image forming means for forming a toner image on a recording material;
Fixing means for fixing the toner image formed on the recording material by heating and pressing;
An image forming apparatus, wherein a fixing condition of the fixing unit is determined in accordance with a determination result by the recording material determination apparatus.

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