1. Field of the Invention
The present invention relates to a recording material image capture device for capturing an image (taking an image) of a surface of a recording material, and to an image forming apparatus.
2. Description of the Related Art
An electrophotographic image forming apparatus such as a copying machine and a laser printer includes an image bearing member for bearing a latent image, a developing device for visualizing the latent image as a developer image by applying a developer to the image bearing member, a transfer unit for transferring the developer image, which is formed by the developing device, onto a recording material conveyed in a predetermined direction under predetermined transfer conditions, and a fixing device for fixing the developer image onto the recording material by heating and pressurizing, under predetermined fixing conditions, the recording material onto which the developer image is transferred by the transfer unit.
Conventionally, in such an image forming apparatus, the size and the type of the recording material are set by a user through a control panel or the like of the image forming apparatus. The image forming apparatus is controlled so that the transfer conditions (for example, the transfer bias voltage or the speed of conveying the recording material in transfer) or the fixing conditions (for example, the fixing temperature or the speed of conveying the recording material in fixing) are set in accordance with the settings.
In recent years, there has also been proposed an image forming apparatus which determines the type of the recording material using a sensor for determining the recording material in the image forming apparatus and controls to set the transfer conditions or the fixing conditions in accordance with the result of the determination.
For example, Japanese Patent Application Laid-Open No. 2010-266432 describes determination of the smoothness of a surface of a recording material with high accuracy by radiating light at a relatively small angle (about 10 to 15 degrees) with respect to the surface of the recording material to be detected, producing a shadow due to unevenness on the surface of the recording material, and capturing an image of the shadow.
Japanese Patent No. 4,447,975 describes suppression of flaps of a recording material by providing an urging plate opposed to a detecting portion of an optical sensor and pressing, with the urging plate, the recording material against the detecting portion of the optical sensor when the recording material to be detected is conveyed.
In Japanese Patent Application Laid-Open No. 2010-266432, light is radiated at a relatively small angle (about 10 to 15 degrees) with respect to the surface of the recording material and a shadow is produced due to unevenness on the surface of the recording material. When an image of the shadow is captured, during the period in which the recording material to be detected is conveyed, the vertical positional variations (flaps) of the recording material are generated to the extent higher than assumed. In such a case, if the property of the surface of the recording material cannot be optically captured with high accuracy, the accuracy of determining the recording material is reduced.
Therefore, as in Japanese Patent No. 4,447,975, the flaps may be suppressed by providing a light transmissive member which passes through light to the side of a sensor for capturing an image of the surface of the recording material and pressing, with the urging plate, the recording material against the light transmissive member. However, depending on the pressing force of the urging plate and the type of the recording material, the light transmissive member is repeatedly rubbed against the conveyed recording material and thus is damaged.
In this case, the sensor for capturing an image of the surface of the recording material receives light which passes through the damaged light transmissive member, and irregular reflection components are increased by the damage. Therefore, there is a problem in that an image of a shadow on the surface of the recording material cannot be captured with high accuracy.
The present invention provides a recording material image capture device and an image forming apparatus which suppress flaps of a recording material and, at the same time, suppress damage to a light transmissive member. According to one embodiment of the present invention, there is provided a recording material image capture device, including: a light radiating unit radiating light to a recording material; an image capture unit receiving the light which is radiated from the light radiating unit and is reflected on a surface of the recording material; a light transmissive member provided between the image capture unit and the recording material to which the light is radiated from the light radiating unit so that the light reflected on the surface of the recording material passes through the light transmissive member; a pressing member provided so as to be opposed to the light transmissive member, pressing the recording material toward the light transmissive member, and rotating along with movement of the recording material which is conveyed on the light transmissive member; an output portion outputting, based on an image captured by the image capture unit, a value related to the recording material to which the light is radiated from the light radiating unit; and the pressing member having a non-contact region which is prevented from contacting with an entire portion corresponding to the image used for determining the recording material, and a contact region which is brought into contact with the recording material.
Further, according to another embodiment of the present invention, there is provided an image forming apparatus, including: a light radiating unit radiating light to a recording material; an image capture unit receiving the light which is radiated from the light radiating unit and is reflected on a surface of the recording material; a light transmissive member provided between the image capture unit and the recording material to which the light is radiated from the light radiating unit so that the light reflected on the surface of the recording material passes through the light transmissive member; a pressing member provided so as to be opposed to the light transmissive member, pressing the recording material toward the light transmissive member, and rotating along with movement of the recording material which is conveyed on the light transmissive member; an output portion outputting, based on an image captured by the image capture unit, a value related to the recording material to which the light is radiated from the light radiating unit; an image forming unit forming a toner image on the recording material, the image forming unit determining image forming conditions based on the output from the output portion; and the pressing member having a non-contact region which is prevented from contacting with an entire portion corresponding to the image used for determining the recording material, and a contact region which is brought into contact with the recording material.
Further, according to another embodiment of the present invention, there is provided a recording material image capture device, including: a light radiating unit radiating light to a recording material; an image capture unit receiving the light which is radiated from the light radiating unit and is reflected on a surface of the recording material; a light transmissive member provided between the image capture unit and the recording material to which the light is radiated from the light radiating unit so that the light reflected on the surface of the recording material passes through the light transmissive member; a pressing member provided so as to be opposed to the light transmissive member, pressing the recording material toward the light transmissive member, and rotating along with movement of the recording material which is conveyed on the light transmissive member; an output portion outputting, based on an image captured by the image capture unit, a value related to the recording material to which the light is radiated from the light radiating unit; and the pressing member having a hard portion and a soft portion, the hard portion being brought into contact with a portion of the recording material other than a portion corresponding to the image used for determining the recording material, the soft portion being brought into elastic contact with the portion of the recording material corresponding to the image used for determining the recording material.
Further, according to another embodiment of the present invention, there is provided an image forming apparatus, including: a light radiating unit radiating light to a recording material; an image capture unit receiving the light which is radiated from the light radiating unit and is reflected on a surface of the recording material; a light transmissive member provided between the image capture unit and the recording material to which the light is radiated from the light radiating unit so that the light reflected on the surface of the recording material passes through the light transmissive member; a pressing member provided so as to be opposed to the light transmissive member, pressing the recording material toward the light transmissive member, and rotating along with movement of the recording material which is conveyed on the light transmissive member; an output portion outputting, based on an image captured by the image capture unit, a value related to the recording material to which the light is radiated from the light radiating unit; an image forming unit forming a toner image on the recording material, the image forming unit determining image forming conditions based on the output from the output portion; and the pressing member having a hard portion and a soft portion, the hard portion being brought into contact with a portion of the recording material other than a portion corresponding to the image used for determining the recording material, the soft portion being brought into elastic contact with the portion of the recording material corresponding to the image used for determining the recording material.
Further features of the present invention will become apparent from the following description of exemplary embodiments with reference to the attached drawings.
A recording material determining device (recording material image capture device) and an image forming apparatus including the recording material determining device according to embodiments of the present invention are described in detail with reference to the attached drawings.
(First Embodiment)
First, structures of a recording material determining device (recording material image capture device) according to a first embodiment of the present invention and an image forming apparatus including the recording material determining device according to the first embodiment are described with reference to
A recording material determining device (recording material image capture device) 50 according to this embodiment can be used for, for example, an electrophotographic color image forming apparatus 3.
<Image Forming Apparatus>
First, a structure and operation of an image forming portion of the image forming apparatus 3 which is used in this embodiment are described with reference to
The image forming portion as an image forming unit for forming a toner image on a recording material P includes a feed cassette 15 serving as a feeding portion and photosensitive drums 1Y, 1M, 1C, and 1Bk serving as image bearing members on which toner images of yellow (Y), magenta (M), cyan (C), and black (Bk) stations are formed, respectively.
The image forming apparatus 3 further includes charging rollers 2Y, 2M, 2C, and 2Bk as primary charging units, exposure light scanner portions 11Y, 11M, 11C, and 11Bk, developing devices 8Y, 8M, 8C, and 8Bk as developing units, the intermediate transfer belt 24 serving as an image bearing member on which a toner image is formed, a driving roller 23 for driving the intermediate transfer belt 24, a stretching roller 13, and a secondary transfer opposing roller 26.
The image forming apparatus 3 further includes primary transfer rollers 4Y, 4M, 4C, and 4Bk, a secondary transfer roller 25 serving as a transfer unit for transferring, onto the recording material P, a toner image formed on the intermediate transfer belt 24, a fixing portion 21 serving as an image fixing unit for fixing, by heating and pressurizing the recording material P, a toner image formed on the recording material P (on the recording material), and a control portion 10 serving as a control unit for controlling the above-mentioned components.
For the sake of convenience of description, the description is sometimes made with regard to photosensitive drums 1 which represent the photosensitive drums 1Y, 1M, 1C, and 1Bk. Other image forming units are described in similar ways.
The photosensitive drums 1Y, 1M, 1C, and 1Bk are respectively formed by applying an organic photoconductive layer on outer peripheries of cylinders made of aluminum, and are rotated by driving force transferred from a driving motor (not shown). The driving motor rotates the photosensitive drums 1Y, 1M, 1C, and 1Bk in a clockwise direction in
When the control portion 10 receives an image signal, the recording material P is fed from the feed cassette 15 or the like by feed rollers 17 and 18 into the image forming apparatus 3. The recording material P is then temporarily nipped between registration rollers 19 serving as roller-like synchronous rotation members for synchronization between the image forming operation and the conveyance of the recording material P, and is stopped to wait.
In accordance with the received image signal, the control portion 10 forms electrostatic latent images with the exposure light scanner portions 11Y, 11M, 11C, and 11Bk on surfaces of the photosensitive drums 1Y, 1M, 1C, and 1Bk which are charged at a predetermined potential by the action of the charging rollers 2Y, 2M, 2C, and 2Bk, respectively.
The developing devices 8Y, 8M, 8C, and 8Bk are units for visualizing, as toner images, the electrostatic latent images formed on the surfaces of the photosensitive drums 1 by supplying toner thereto, and develop images of yellow Y, magenta M, cyan C, and black Bk of the respective stations. The developing devices 8 are provided with developing sleeves 5Y, 5M, 5C, and 5Bk, respectively, and developing bias voltage for visualizing the electrostatic latent images is applied to the developing sleeves 5.
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, respectively.
The photosensitive drum 1, the charging roller 2, and the developing device 8 are integrally formed, and are mounted to a main body of the image forming apparatus 3 in the form of a toner cartridge 31 which is removable therefrom.
The intermediate transfer belt 24 is separately held in contact with the surfaces of the photosensitive drums 1Y, 1M, 1C, and 1Bk, and, when a color image is formed, rotates in the counterclockwise direction in
After that, the multicolored toner image formed on the intermediate transfer belt 24 is conveyed into a secondary transfer nip portion formed by the secondary transfer roller 25 and the intermediate transfer belt 24. At the same time, the recording material P which has been waiting under a state of being nipped between the registration rollers 19 is conveyed into the secondary transfer nip portion by the action of the registration rollers 19 in synchronization with the multicolored toner image on the intermediate transfer belt 24. The multicolored toner image on the intermediate transfer belt 24 is collectively transferred onto the recording material P by the action of secondary transfer bias voltage applied to the secondary transfer roller 25.
The fixing portion 21 fuses and fixes the transferred multicolored toner image while conveying the recording material P, and, as illustrated in
The fixing roller 21a and the pressure roller 21b are formed into a hollow shape, and include therein heaters 21ah and 21bh, respectively.
The recording material P having the multicolored toner image is conveyed by the fixing roller 21a and pressure roller 21b, and heat and pressure are applied thereto to fix the toner on a surface of the recording material P
The recording material P after the toner image is fixed thereon is discharged by delivery rollers 20 onto a delivery tray 16, and the image forming operation ends.
A cleaning blade 28 serving as a cleaning unit removes transfer residual toner which remains on the intermediate transfer belt 24. The transfer residual toner is collected and accumulated in a waste toner container 29 as waste toner.
This series of image forming operations is controlled by the control portion 10 provided in the image forming apparatus 3.
In the image forming apparatus 3 illustrated in
The control portion 10 determines the optimum image forming conditions of the image forming unit based on the determination information (result of determination) of the recording material P which is sent from the recording material determining device 50, and controls to operate the image forming apparatus 3. Further, the control portion 10 determines the optimum transfer bias voltage to be the transfer conditions of the secondary transfer roller 25 serving as the transfer unit and controls to operate the image forming apparatus 3. Still further, the control portion 10 determines the optimum fixing temperature and the like to be the fixing conditions of the fixing portion 21 serving as the fixing unit and controls to operate the image forming apparatus 3.
<Recording Material Determining Device>
Next, a structure of the recording material determining device 50 of this embodiment is described. Note that, the recording material determining device 50 is a recording material image capture device which captures (takes) an image of a surface of a recording material for the purpose of determining the surface property of the recording material.
<Comparative Example and Problem Thereof>
A structure of a comparative example and a problem thereof are described with reference to
In this case, as to the radiating directions of optical axes 66R1 and 66L1 radiated by the light sources 61R and 61L, as illustrated in
The cover member 68 serving as a light transmissive member is provided between the recording material P to which light is radiated by the light sources 61R and 61L and a linear image capture element 63 serving as an image capture unit for receiving light reflected on the surface of the recording material P (surface of the recording material), and light reflected on the surface of the recording material P (surface of the recording material) passes therethrough.
The optical axes 66R2 and 66L2 are guided and deflected by the deflectors 64R and 64L. Thereby, light is radiated to the surface of the recording material P through the transparent cover member 68. This enables detection of the property of the surface of the recording material P (unevenness due to paper fibers or the like of the recording material P) as the variations of light and dark (shadow). The linear image capture element 63, which includes a plurality of light receiving pixels mounted on the base plate 65 and arranged in a line, captures an image reflecting the property of the surface of the recording material P as the distribution of light and dark via a light collecting element 62 which is a rod lens.
Based on the obtained image which reflects the property of the surface of the recording material P, an optical feature value such as the contrast is extracted and calculated. Based on the value, the surface property of the recording material P can be determined (the type of the recording material P can be determined). The determination of the surface property of the recording material P specifically means that, based on the output from the image capture element 63, a determining portion (output portion) 69 provided on the base plate 65 extracts and calculates the above-mentioned optical feature value, and, based on the value, outputs a value related to the surface property of the recording material P subjected to the image capture operation to the control portion 10.
In this embodiment, as illustrated in
The imaginary optical axis lines are illustrated with the observation image centers T being the optical centers. At the same time, effective radiation regions E on the surface of the recording material P (surface of the cover member 68) are indicated by oval broken lines in
Further, imaginary optical axes 66R3 and 66L3 illustrated in
Reference coordinates of arranging the respective components are described using the X axis, the Y axis, and the Z axis in
Specifically, optical feature values such as the contrast for the portions in the image corresponding to the effective radiation regions ER and EL of the recording material P are extracted and calculated and, based on the values, the surface property of the recording material P is determined (the type of the recording material P is determined).
With respect to the recording material determining device 50 having such an optical system, it is desired that the recording material P is pressed against the surface of the cover member 68 so that the surface of the recording material P can be observed with high accuracy. By conveying the recording material P while pressing the recording material P against a flat portion of the surface of the cover member 68 with predetermined force, positional variations of the surface of the recording material P can be set within an allowable range of depth of the optical system.
The above-mentioned state is described by way of a comparative example illustrated in
Such a structure enables reduction in the variation amount of the recording material P from the surface of the cover member 68 when the recording material P is conveyed. Exemplary results of measurement of the variation amount of the surface of the recording material P from the surface of the cover member 68 using a laser displacement meter are shown in
However, when a large number of recording materials P of various types are conveyed using the roller 70 while pressing the recording materials P, the surfaces of the recording materials P and the cover member 68 are rubbed against each other. Therefore, as illustrated in
As illustrated in
The surface of the recording material P is observed at the nip portion of the recording material P. When the property of the surface of the recording material P is determined, the abrasion D caused on the surface of the cover member 68 induces irregular reflection components for the optical observation system, and the amount of light is reduced and noise components due to the optical factor are caused. Therefore, it becomes difficult to obtain expected observation data of the surface of the recording material P, and there arises a problem in that the accuracy of determining the recording material P is reduced.
A simple way to solve this problem is thought to be reduction of the pressing force F applied by the roller 70, because the abrasion D is thought to be less liable to be caused. However, the variation amount of the recording material P becomes less liable to be controlled.
In order that the nip point on the roller 70 which is pressed by the roller 70 as a factor of causing the abrasion D is prevented from being coincident with the detection point by the optical system, the nip point formed by the roller 70 may be shifted upstream or downstream in the conveyance direction of the recording material P. However, the length of the abrasion D in the conveyance direction of the recording material P is several millimeters or more, and thus, it is necessary to effect the shift by a distance of several millimeters or more from the detection point by the optical system. If such a structure is adopted, the pressing and restraining force for the recording material P is inevitably reduced, and it becomes difficult to observe the surface of the recording material P with stability.
In order to solve the problem of the comparative example illustrated in
In
Based on an image captured by the image capture element 63, the recording material determining device 50 determines the type of the recording material P to which light is radiated from the light sources 61. A recess portion 71a serving as a non-contact region, which is not brought into contact with the entire portion corresponding to the image used for determining the recording material P, is provided in a center portion in an axial direction of a cylindrical portion of the roller 71. Projecting portions 71b serving as contact regions, which are brought into contact with the recording material P, are provided on both sides of the recess portion 71a serving as the non-contact region of the roller 71 in a direction orthogonal to the conveyance direction of the recording material P.
The recess portion 71a serving as the non-contact region of the roller 71 does not nip or come into contact with the recording material P. As illustrated in
By providing the recess portion 71a serving as the non-contact region of the roller 71, the pressing and restraining force for the recording material P is reduced. This allows variations of the surface of the recording material P to some more extent compared with the variation amount of the surface of the recording material P in the comparative example shown in
With regard to the direction of the X axis illustrated in
At locations corresponding to portions other than the recess portion 71a of the roller 71 at which the recording material P is pressed, the abrasion D similar to that in the comparative example was caused. In this way, even after a large number of the recording materials P are conveyed, the abrasion D is not caused at the location on the surface of the cover member 68 which corresponds to the recess portion 71a of the roller 71, and the surface of the cover member 68 does not change. The state of the surface of the recording material P which is observed with light radiated thereto is maintained at the initial state. Therefore, in this embodiment, a satisfactory state for observation is maintained before and after a large number of the recording materials P are conveyed.
This means that the accuracy of determining the recording material P in the initial state can be maintained for a long period of time. A structure was realized, which minimized variations of the surface of the recording material P and still did not reduce the accuracy of the determination due to irregular reflection components that were caused by the abrasion D on the surface of the cover member 68. According to the above-mentioned structure, flaps of the recording material are suppressed by the contact regions which are brought into contact with the recording material, and at the same time, the non-contact region, which is not brought into contact with the entire portion corresponding to the image used for determining the recording material, can suppress damage to the light transmissive member.
Light is radiated from two directions to the moving recording material P, and the property of the surface of the recording material P is observed to determine the type of the recording material P. In this case, in order to hold the variations of the surface of the recording material P within an optical guaranteed range of measurement, the roller 71 for pressing the recording material P against the observation surface is used. By providing the recess portion 71a in a part of the roller 71, even if a large number of the recording materials P of various types are conveyed, the performance of observing the property of the surface of the recording material P can be maintained for a long period of time. This enables assurance of the accuracy of determining the recording material P. Further, the recording material determining device 50 of this embodiment is small in size and can be formed at a low cost, and a device having a high accuracy of determining the recording material P can be realized.
This embodiment is described using surface mounted LEDs as the light sources 61. However, insofar as light can be radiated to the recording material P from two directions with respect to the conveyance direction under predetermined conditions, shell-type LEDs may be adopted, and other illumination units may also be used.
Illumination light from the light sources 61 was guided to the surface of the recording material P using light guiding members such as the deflectors 64. However, it is not necessary to use the light guiding members, and optical paths may be set and light guide paths using reflectors or the like may be set.
(Second Embodiment)
Next, a structure of an image forming apparatus including a recording material determining device (recording material image capture device) according to a second embodiment of the present invention is described with reference to
In this embodiment, the two light sources 61R and 61L for radiating light to the recording material P from different directions are provided as the light radiating unit. A roller 72 which serves both as a pressing member and a rotating member includes recess portions 72a1 and 72a2 serving as two non-contact regions corresponding to portions of the recording material P to which light is radiated from the two light sources 61R and 61L, respectively.
A projecting portion 72b1 serving as a contact region is provided between the recess portions 72a1 and 72a2 serving as the non-contact regions in a direction orthogonal to the conveyance direction of the recording material P (axial direction of the roller 72), and further, projecting portions 72b2 and 72b3 serving as contact regions are provided on both sides of the recess portions 72a1 and 72a2, respectively.
Various types of the recording material P are used, and the main body of the image forming apparatus 3 is used in various environments. It cannot be completely ensured that the recording material P is conveyed without fail and with stability in the range of the recess portion 71a of the roller 71 of the above-mentioned first embodiment. In the recording material determining device 50, the effective radiation regions ER and EL for determining the recording material P are set on both sides within the recess portion 71a provided on the cylindrical roller 71.
Conversely, the location between the set effective radiation regions ER and EL is not involved in the measurement for determining the recording material P. By additionally providing the projecting portion 72b1 at the location which is not involved in the detection and determination of the recording material P and providing pressing portions for pressing the recording material P on both sides of the recess portions 72a1 and 72a2, respectively, and at the portion therebetween, conveyance of the recording material P can be realized with stability.
As shown in
In this embodiment, by additionally providing the projecting portion 72b1 serving as the pressing portion for pressing the recording material P to the maximum extent insofar as the measurement is not affected, the variation amount when the recording material P is conveyed can be further suppressed. The image forming apparatus 3 is robust against change in measurement conditions due to external factors such as the recording material P of various types and the usage environment of the image forming apparatus 3, and, as a result, the accuracy of determining the recording material can be stabilized. The structure is otherwise similar to that of the above-mentioned first embodiment, and similar effects can be obtained. According to the above-mentioned structure, flaps of the recording material are suppressed by the contact regions in contact with the recording material, and at the same time, the non-contact regions, which are not brought into contact with the entire portions corresponding to the image used for determining the recording material, can suppress damage to the light transmissive member.
(Third Embodiment)
Next, a structure of an image forming apparatus including a recording material determining device (recording material image capture device) according to a third embodiment of the present invention is described with reference to
The roller 74 of this embodiment has ends (hard portions) 75 formed of hard members having a Rockwell hardness of 80 to 120 serving as contact regions which are brought into linear contact with the recording material P. The roller 74 further has a center portion (soft portion) 76 formed of a soft member having an Asker C hardness of 10 to 30 or a rubber hardness of 10 to 30 serving as a contact region which is brought into elastic contact with the recording material P.
In this embodiment, a new pressing member (center portion 76) is added to the recess portion 71a of the roller 71 of the first embodiment illustrated in
Various types of the recording material P are used, and the main body of the image forming apparatus 3 is used in various environments. Thus, it cannot be completely ensured that the recording material P is conveyed without fail and with stability in the range of the recess portion 71a of the roller 71 of the above-mentioned first embodiment. Providing a unit for actively pressing and urging the cover member 68 may induce damage to the surface of the cover member 68.
As a measure against that, in the above-mentioned first embodiment, the recess portion 71a is provided in a part of the outer peripheral surface of the roller 71 as a pressing member. In this embodiment, the structure of the cylindrical roller 74 is divided into two components, that is, the ends 75 and the center portion 76.
At portions where damage to the cover member 68 is allowable (portions which are brought into contact with portions which do not correspond to the image used for determining the recording material), the ends 75 are formed of a relatively hard material typified by resin members as the body of the roller 74, and actively press the recording material P to suppress the variation amount of the recording material P.
On the other hand, at the center portion 76 where damage to the cover member 68 is not desired (portion which is brought into contact with a portion corresponding to the image used for determining the recording material), the center portion 76 is formed of a relatively soft material such as so-called rubber or sponge. Such a soft member elastically presses and supports the recording material P to some extent from behind, but does not actively urge and pressurize the recording material P. This suppresses the variation amount of the surface of the recording material P, and at the same time, suppresses damage to the cover member 68.
The center portion 76 formed of the soft member is not a complete space, and thus, slight pressing force is generated. If the abrasion D of the cover member 68 is allowable within the range of the number of the conveyed recording materials P which is set taking the life of the image forming apparatus 3 into consideration, this embodiment can be adopted.
In this embodiment, by appropriately changing the hardness of the pressing portions which press the recording material P and setting the center portion 76 as a separate soft member, both suppression of the variation amount of the recording material P when the recording material P is conveyed and suppression of damage to the cover member 68 can be accomplished. That is, in this embodiment, in the pressing member, the hardness of the portion which is brought into contact with a portion corresponding to the image used for determining the recording material (soft portion) is set smaller (softer) than the hardness of the portions which are brought into contact with portions which do not correspond to the image used for determining the recording material (hard portions). In this way, the variation amount of the recording material P when the recording material P is conveyed is suppressed, and at the same time, damage to the cover member 68 is suppressed. The structure is otherwise similar to those of the above-mentioned embodiments, and similar effects can be obtained. According to the above-mentioned structure, flaps of the recording material are suppressed by the contact regions which are brought into contact with the recording material, and at the same time, the soft portion which is brought into contact with the portion corresponding to the image used for determining the recording material can suppress damage to the light transmissive member.
(Fourth Embodiment)
Next, a structure of an image forming apparatus including a recording material determining device (recording material image capture device) according to a fourth embodiment of the present invention is described with reference to
In this embodiment, the structure of the roller 71 including the recess portion 71a of the first embodiment illustrated in
Various types of the recording material P are used, and the main body of the image forming apparatus 3 is used in various environments. Thus, it cannot be completely ensured that the recording material P is conveyed without fail and with stability in the range of the recess portion 71a of the roller 71 of the first embodiment illustrated in
Therefore, in this embodiment, another exemplary structure of the cylindrical roller 77 is described.
As illustrated in
The cylindrical member 80 is movable independently of the body portion of the roller 77 in a direction in which the body portion of the roller 77 presses the recording material P toward the cover member 68.
Now, the gap G on the lower side is lost and the gap on the upper side is “2×G” at the maximum as illustrated in
When the recording material P is normally conveyed, the cylindrical member 80 rotates and, at the same time, moves by about a variation amount which is equal to or smaller than the size of the gap G, to thereby maintain a state in which the variation amount of the recording material P when the recording material P is conveyed is relatively mildly restrained. In this case, the force of pressing the surface of the cover member 68 by the recording material P is small, and thus, the abrasion D is not caused in the effective radiation regions ER and EL in the cover member 68.
In this embodiment, by adding, to the roller 77, the cylindrical member 80 for mildly restraining the variation amount of the recording material P, both suppression of the variation amount of the recording material P when the recording material P is conveyed and suppression of damage to the cover member 68 can be achieved. The structure is otherwise similar to those of the above-mentioned embodiments, and similar effects can be obtained. According to the above-mentioned structure, flaps of the recording material are suppressed by the contact regions which are brought into contact with the recording material, and at the same time, the cylindrical member which is brought into contact with the portion corresponding to the image used for determining the recording material can suppress damage to the light transmissive member.
While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.
This application claims the benefit of Japanese Patent Application No. 2012-270253, filed Dec. 11, 2012, which is hereby incorporated by reference herein in its entirety.
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2012-270253 | Dec 2012 | JP | national |
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