Patent Application
20080001348
Hereinafter, a detailed description will be made of a sheet material information detection apparatus according to an embodiment of the present invention with reference to the drawings. The sheet material information detection apparatus according to the present invention is not limited to a limitative structure according to embodiments described below. As long as an external force application unit is received by an external force receiving member through an intermediation of a sheet material, another embodiment may be achieved, in which a part or a whole of structures of the embodiments may be replaced with an alternative structure.
In this embodiment, a description is made of an example in which the sheet material information detection apparatus is mounted on an electrostatic image forming apparatus. However, the sheet material information detection apparatus may be mounted on an ink jet image forming apparatus, various printing devices, or various sheet material processing apparatus such as a sheet material processing device, a sheet material stacking devices, or a sorter.
Note that, the structure, operation, control, operation principle of the sheet material information detection apparatus, signal processing, and the like of the image forming apparatus disclosed in each of the patent documents described above will not be illustrated in the drawings and descriptions thereof will also be omitted for avoiding redundancy.
As illustrated in
On the other hand, the sheet material P accommodated in a cassette 321 is sent to a transporting unit 112 by a transmission roller 322. In a position adjacent to the transporting unit 112, there is provided the sheet material information detection apparatus 100. The sheet material information detection apparatus 100 is arranged so as to sandwich, from above and below, a transporting position of the sheet material P, being passed from the transmission roller 322 to the transporting unit 112. The sheet material information detection apparatus 100 detects sheet material information (mechanical property) of the sheet material P passing through the transporting position.
A control unit 120 identifies the sheet material information on the sheet material P detected by the sheet material information detection apparatus 100 before the image formation is performed by the image formation process unit 340, and sets an optimum transporting condition, transfer condition, fixing condition, or the like.
Next, the sheet material P is sent to a drum 330. A peripheral surface of the drum 330 is provided with a dielectric sheet. The sheet material P is sucked and carried on by a surface of the drum 330 charged by a suction corona discharger 331. After that, due to an action of the suction corona discharger 332, a toner image on a photosensitive drum 323 is transferred to a sheet material P.
A surface of the photosensitive drum 323 is cleaned by a blade cleaner 324. A pre-exposure lamp 325 and a front static eliminator 326 eliminate an effect remaining on a photosensitive member surface layer due to the last image formation. Next, a surface of the photosensitive drum 323 is uniformly charged by a primary charger 327. A charge amount at this time is determined based on the sheet material information on the sheet material P.
A laser beam scanner 328 scans the surface of the photosensitive drum 323 to form an electrostatic latent image based on the different color signals of the color original 312 obtained by reading. A developing device 329 includes developing units of four colors, which are cyan, magenta, yellow, and black. The developing units corresponding to respective colors successively move to a position directly below the photosensitive drum 323 to develop the latent image on the photosensitive drum 323 to a toner image.
The sheet material P is sucked and carried on the drum 330 until the toner image of four colors is successively transferred. After that, the sheet material P is separated from the drum 330 by an action of a separation claw 333. The separated sheet material P is sent to a heating roller fixing device 335 by a conveyor belt 334 and heat and pressure are applied thereto, so a toner image is fixed onto a surface of the sheet material P. A fixing temperature at this time is determined based on sheet material information on the sheet material P.
The sheet material P after completion of the fixation is delivered onto a tray 336. Toner remaining on the surface of the photosensitive drum 323 after completion of the transfer is cleaned by the blade cleaner 324, and a process advances to a next image formation cycle.
As illustrated in
The sheet material information detection apparatus 100 has a structure in which an external force detection unit 2 detects an external force, which is applied by the external force application section 1 for applying an external force to the sheet material P, through the sheet material P. A converting unit (charge amplifier) 123 converts a change in volume of a pressure-sensitive element 2b due to deformation thereof into a change in voltage signal. The control circuit 121 detects a peak value of the voltage signal output from the converting unit 123 to take out the sheet material information. The sheet material information corresponds to a peak value of an impact force detected through the sheet material P, and reflects mechanical property and a moisture amount of the sheet material P.
The external force application unit 1 includes an end portion (side coming into contact with the sheet material P) 1a, a shaft 1b, and a pin 1c coming into contact with the cam 4. The end section 1a is made of SUS 304, that is, a stainless steel material, and has a contact surface with respect to the sheet material P, which is subjected to spherical working so as to have a radius of 20 mm. A mass of the external force application unit 1 as a whole is 4 g.
A driving unit for driving the external force application unit 1 includes the motor 3, the cam 4, a spring 5 as an acceleration unit. Used as the motor 3 is a stepping motor. The cam 4 is rotated by a requisite angle from a stop position and is returned again to the stop position. At the stop position, the rotation of the cam 4 is started, external application is then performed twice, and the cam 4 then returns again to the stop position (retraction position), thereby completing one cycle. Time required for one cycle is 0.2 seconds. An interval between two times of external force applications is 0.1 seconds.
One cycle is started after a predetermined time has elapsed from reception of a signal of a sheet material passage detection sensor (not shown). The cam 4 lifts the external force application unit 1 against a force of the spring 5 and releases the external force application unit 1. The cam 4 compresses and releases the spring 5 twice in a process of one rotation, and strikes out the external force application unit 1 toward the sheet material P.
The normal stop position of the cam 4 is set to a position before a position where the cam 4 allows the spring 5 to be compressed to a maximum degree during the rotation process of the cam 4. When the cam 4 is at the stop position, the external force application unit 1 is spaced apart from the sheet material P to a maximum degree. The stop position is the same as the retraction position. The external force application unit 1 impacts on the sheet material P at a predetermined speed corresponding to a height to which the external force application unit 1 is lifted by the cam 4, thereby performing external force application. The cam 4, the spring 5, and the external force application unit 1 are designed such that an impact speed in a first external force application is 0.5 m/sec, and an impact speed in a second external force application is 0.2 m/sec.
During one rotation of the cam 4 by the motor 3, there is effected a process of temporarily stopping the rotation. This is effected to wait for unnecessary vibration of the spring 5 and the external force application unit 1 involved in the striking and impacting of the external force application unit 1 to attenuate. The temporary stop of the rotation of the cam 4 is performed when the cam 4 is in a positional range where the cam 4 allows the spring 5 to be compressed.
The external force detection unit 2 is placed so as to be opposed to the external force application unit 1 through the intermediation of the sheet material P. The external force detection unit 2 includes an impact receiving unit 2a and a reinforcing member 2c, and the pressure-sensitive element 2b integrally sandwiched therebetween. The impact receiving unit 2a receives impact of the external force application unit 1 through the sheet material P and exerts a compression force to the entire surface of the pressure-sensitive element 2b. The reinforcing member 2c reinforces the pressure-sensitive element 2b to suppress deformation other than compression, in particular, bending deformation of the pressure-sensitive element 2b.
The reinforcing member 2 fixing the impact receiving unit 2a and the pressure-sensitive element 2b is bonded to a sheet material support unit 17. For the pressure-sensitive element 2b, lead zirconate titanate (PZT) ceramics is used, for the reinforcing member 2c, SUS 304 is used, and the pressure-sensitive element 2b and the reinforcing member 2c are bonded to each other by an epoxy resin.
The sheet material information detection apparatus 100 is provided with a sheet material presser 7 on an inlet side and a sheet material presser 6 on an outlet side, the sheet material presser 7 and the sheet material presser 6 sandwiching the external force detection unit 2 therebetween. The sheet material pressers 6 and 7 suppress flapping of the sheet material transported between transport guides 9, thereby reproducing relative heights of the sheet material P and the external force detection unit 2 at the time of impacting of the external force application unit 1 to be constant. The sheet material pressers 6 and 7 support displacement members 11, that is, metal members which are subjected to curved surface working so as to dissipate impact shock due to the impact caused through transportation of the sheet material P, in a vertically movable manner, and allow the displacement members 11 to be pressed to the sheet material P by pressing springs 12. A pressing force of the sheet material pressers 6 and 7 is determined according to a thickness of the sheet material P or the like, but is 1 N (100 gf) in Embodiment 1.
The abnormality sensing unit for sensing abnormality of the sheet material P includes the sheet material presser 7 which comes into contact with the sheet material P to be displaced, and the push-in sensing unit 8 which senses that the sheet material presser 7 is pushed in by the sheet material P. The abnormality sensing unit is illustrated in detail in
The sheet material P is transported when being pressed by the displacement member 11 and a pressing spring 12 toward the sheet material support unit 17. In the normal state, due to the pressing pressure, the sheet material P is transported in a state where a shaft 14 and a contact point 16 of a switch 15 do not come into contact with each other. However, when the displacement member 11 is pushed up by the sheet material P in which folding is caused due to sheet clogging at the time of abnormality, the shaft 14 and the contact point 16 come into contact with each other, and abnormality sensing is performed by sensing the contact.
The sheet material support member 17 has a first function of sandwiching the sheet material between the sheet material pressers 6 and 7 and itself as an opposing member. The sheet material support member 17 has a second function of imparting certain deflection to the sheet material in order to accurately obtain information related to the deflection of the sheet material. The sheet material support member 17 further has a third function of preventing the sheet material from causing clogging or being damaged by entering a recess (groove) at the time of transporting the sheet material in a case where the external force detection unit 2 is provided in the recess formed in the sheet material transport path.
As illustrated in
Except for presence/absence of the switch 15, the sheet material presser 7 is made of the same material, and has the same shape as the sheet material presser 6. Note that, a pressing force of the sheet material presser 7 is a little smaller value than that of the sheet material presser 6 on the downstream side, thereby being 0.8 N (80 gf). The shaft 14 connected to the displacement member 11 is supported by the direct-acting bearing 13 so as to be freely movable in a vertical direction of
As illustrated in
However, as illustrated in
When, in the retained state, the sheet material P pushes up the displacement member 11 by a certain distance (0.7 mm) or more, the shaft 14 and the contact point 16 come into contact with each other, thereby allowing the switch 15 to be turned on. When the switch 15 is turned on, the control circuit 121 determines that the state of the sheet material P is abnormal. When a pushed amount of the displacement member 11 by the sheet material P is less than 0.7 mm, the switch 15 is kept in an off state, and the control circuit 121 determines that the state thereof is normal.
A state of the sheet material P, which is determined to be abnormal by the control circuit 121, is a state where at least a part of the transported sheet material P is bent, folded, or damaged, two or more sheet materials P overlap each other, or a sheet material having unexpected thickness or material is fed. When, by the sheet material P transported between the transport guides 9, the displacement member 11 is pushed up or is flipped up to undergo displacement of certain conditions, the control circuit 121 determines that the state is abnormal.
Determination results of the control circuit 121 are transmitted to the control unit 120 of the image forming apparatus 300 (
With reference to a flow chart of
As illustrated in
Subsequently, in the control circuit 121 for the sheet material information detection apparatus 100, sheet material transport information is input (S12). The sheet material transport information is information related to a position or a speed of the sheet material P, and indicates a timing at which the sheet material P passes through the sheet material information detection apparatus 100. According to the sheet material transport information, a timing of driving (external force application or the like) of the sheet material information detection apparatus 100 is determined. The sheet material transport information has a form of, for example, a signal of the sheet material passage sensor (not shown) of the sheet material information detection apparatus 100 or a signal obtained by processing information related to an operation start (operation in which a copy button is pressed, or the like) of the sheet material information detection apparatus 100.
Subsequently, when receiving the sheet material transport information, the control circuit 121 starts the operation of the sheet material information detection apparatus 100 (S13). As the operation of sheet material information detection, the control circuit 121 performs the abnormality sensing of the sheet material (S14). The control circuit 121 determines that, when the switch 15 is in an on state, the state is abnormal. Note that, in order to prevent an erroneous operation due to vibration or flipping up of a leading end of the sheet material at a time of passage thereof, in a case where the on state satisfies certain conditions, it is determined that the state is abnormal (YES in S14). An example of the certain conditions is conditions in which the switch 15 is kept in the on state for a predetermined time period. As a result, the control circuit 121 can determine a case, where the sheet materials P are double-fed or a loop thereof becomes too large, to be abnormal.
Another example of the certain conditions includes conditions in which a predetermined times or more of the on states are recognized in a certain time period. In this example, the abnormality can be sensed when vibration is caused because the sheet material is folded or wrinkled. In Embodiment 1, in a case where, during a time period in which the sheet material P passes through a position of the sheet material information detection apparatus 100, the on state of the switch 15 is kept for 0.01 or more seconds, the control circuit 121 determines the state as YES (abnormal). In a case where, even after 0.1 or more seconds have elapsed from a time point at which the leading edge of the sheet material P passes a position of the sheet material presser 7, the switch 15 is not turned on, the control circuit 121 determines the state as NO (normal).
In the case of YES (abnormal), the external force application unit 1 is retracted upwardly (S19). In Embodiment 1, when the cam 4 is at any rotation position, the control circuit 121 immediately allows the motor 3 to rotate at high speed, to thereby lift the external force application unit 1 to a highest retraction position for retraction. The control circuit 121 performs an abnormality information output indicating that the sheet material P is in the abnormal state with respect to the control unit 120.
In the case of NO (normal), the control circuit 121 allows the motor 3 to rotate and allows the cam 4 to make the external force application unit 1 strike out, thereby applying an external force to the sheet material P (S15). As a result, the external force detection unit 2 receives the external force of the external force application unit 1 through intermediation of the sheet material. The external force detection unit 2 inputs a voltage signal to the control circuit 121 through the converting unit 123 (S16). The control circuit 121 detects a peak of the voltage signal and outputs the peak to the control unit 120 as the sheet material information (S17). The control unit 120 selects optimum process conditions for image formation according to the sheet material information, thereby performing an appropriate sheet material processing.
As described above, in Embodiment 1 of the present invention, the abnormality of the sheet material P is sensed to retract the external force application unit 1 of the sheet material information detection apparatus 100. According to the control of Embodiment 1, by retracting the external force application unit 1, even in a case where there is abnormality of the sheet material P which is fed, the sheet material P which is transported can be prevented from being caught by the external force application unit 1, or the external force application unit 1 can be prevented from being applied with a strong force. When the jammed sheet material P is removed, the external force application unit 1 is not strained. Thus, a trouble such as breakage of the sheet material information detection apparatus 100 can be avoided.
As illustrated in
The shaft 1b of the external force application unit 1 is supported so as to be movable in a direction of the shaft by the bearing 1e. The external force application unit 1 also serving as the displacement member is pressed downwardly by the spring (pressing spring) 5. The shaft 1b of the external force application unit 1 is in conduction with the bearing 1e and is insulated from a housing 23 and the transport guides 9. That is, pushing up of the external force application unit 1 by the contact with the sheet material P is detected by the contact point 26. The sheet material P is transported in a state where the sheet material P does not come into contact with the external force application unit 1 or in a state where a excessive pressure is not applied to the external force application unit 1. However, when the external force application unit 1 is flipped up by the sheet material P in the abnormal state, the pin 1c and the contact point 26 come into contact with each other, and the control circuit 125 senses the contact, thereby performing the abnormality sensing.
The above-mentioned structure will be described in more detail. A push-in sensing unit 25 is formed of an elastic electrode member. The contact point 26 at a distal end of the push-in sensing unit 25 is set to a high position of a stroke of the pin 1c of the external force application unit 1. That is, when the motor 3 rotates the cam 4, the pin 1c of the external force application unit 1 does not come into contact with the contact point 26 of the push-in sensing unit 25 except for a certain time period approaching the retraction time, illustrated in
For the push-in sensing unit 25 used for the abnormality sensing, a conductive plate spring is used, a distal end unit thereof is bent to constitute the contact point 26, and a proximal end thereof is fixed to the housing 23 by a screw. Further, by wirings (not shown), a unit between the contact point 26 and the pin 1c is supplied with an electric potential for allowing electrical sensing of the contact therebetween. It is preferable that a spring constant of the plate spring be set such that a reaction force caused at the time of contact is small enough with respect to a driving force used for the external force application.
The external force application unit 1 as the displacement member is identical in material and shape to the external force application unit 1 of Embodiment 1. The spring 5, the bearing 1e, and the shaft 1b have the same structures as those of the corresponding members of Embodiment 1. Note that, the wirings for supplying the potential for the electrical sensing of the contact between the external force application unit 1 and the push-in sensing unit 25 are additionally provided.
As illustrated in
However, as illustrated in
The above descriptions are outlines of the structure and the operation of this embodiment. In Embodiment 2 of the present invention, when the external force application unit 1 is flipped up to be displaced by the sheet material P, the contact point 26 is in the on state. A range in which the contact point 26 is in the on state is set to be a range from the retraction position to a position spaced apart therefrom by 0.5 mm or less.
Further, in Embodiment 2, when, during a time period in which the sheet material P passes through the sheet material information detection apparatus 400 (at a timing at which the contact point 26 and the external force application unit 1 do not come into contact with each other in the normal state), the sheet material P is flipped up even once, the control circuit 125 immediately determines that there is the abnormality of the transportation. However, after that, in a case where the jam is not caused, and it is confirmed by a sensor (not shown) that the sheet material P has passed through the sheet material information detection apparatus 400, the control circuit 125 determines that the state has returned to the normal state.
A state of the sheet material P detected to be abnormal in Embodiment 2 is the same as Embodiment 1. When the transported sheet material P pushes up or flips up the external force application unit 1 to allow the external force application unit 1 to be displaced by a certain amount or more, the control circuit 125 determines this as the abnormality. In Embodiment 2, in particular, direct impact of the sheet material P with respect to the external force application unit 1 is detected, so the trouble of breakage of the external force application unit 1 can more effectively be avoided.
As illustrated in
The external force application unit 1 as the displacement member which is displaced by coming into contact with the sheet material P is provided with a mirror surface if on a side surface of the shaft unit 1c. The external force application unit 1 is pushed up by the cam 4 against downward bias by the spring (pressing spring) 5 and is released to be allowed to strike out toward the sheet material P. The external force detection unit 2 receives, through the intermediation of the sheet material P, the external force application unit 1 which is allowed to strike out, and outputs the voltage signal reflecting mechanical property and a moisture amount of the sheet material through the converting unit 123 (
The optical sensor 31 which serves as the push-in sensing unit of the external force application unit 1 includes, as illustrated in
As illustrated in
As illustrated in
Note that, in
As illustrated in
As illustrated in
A clip 53 is provided so as to rotate to a side as illustrated in
The external force detection unit 2 arranged so as to be opposed to the external force application unit 1 receives the external force application unit 1 allowed to strike out as illustrated in
In the normal state, as illustrated in
However, in the abnormal state, as illustrated in
In this embodiment, without depending on the control circuit, the motor, the cam, or the optical sensor, the whole mechanism on the external force application side assembled on the fixing plate 51 instantaneously retracts upwardly by a simple mechanical mechanism. Therefore, damage or adjustment deviation in the vicinity of the external force application unit 1 involved in the impact of the sheet material P or the removal of the jammed sheet can be avoided.
As illustrated in
Subsequently, in the control circuit of the sheet material information detection apparatus 100, the sheet material transport information is input (S32). The sheet material transport information is information related to a position or a speed of the sheet material. That is, the sheet material transport information means a timing at which the sheet material passes the position of the sheet material information detection apparatus. Based on the sheet material transport information, a timing for driving the sheet material information detection apparatus 100 (such as external force application) is determined. The sheet material transport information, for example, a signal of the sheet material passage sensor of the image forming apparatus 300 and information including the operation start or the like of the image forming apparatus 300.
Subsequently, by receiving the sheet material transport information, the operation of the sheet material information detection is started (S33).
Subsequently, abnormality sensing of the sheet material is performed (S34). In this abnormality sensing processing, between cases where abnormality is sensed or where abnormality is not sensed, the following flow differs.
First, a description will be made of the case where the abnormality is not sensed (NO in S34). Following the prior item (S34), the sheet material information detection apparatus 100 detects the sheet material information. Subsequently, based on the sheet material information, the sheet material processing conditions are determined (S36). Next, based on the determined sheet material processing conditions, the sheet material processing such as image formation is performed (S37). After the above-mentioned process, the operation ends (S38).
Next, a description will be made of the case where the abnormality is sensed (YES in S34). Following the prior item (S34), the external force application unit 1 of the sheet material information detection apparatus 100 is retracted (S39). Subsequently, the abnormality information is output to the sheet material information detection apparatus 100 (S40).
After that, whether or not the abnormality is released is determined for a predetermined time period (S41). In a case where the sheet material P passes through the sheet material information detection apparatus 100 to release the abnormality (YES in S41), the operation of the sheet material information detection apparatus 100 is stopped and then the sheet material processing is performed under default conditions (S42). In a case where the abnormality is determined to be minor, the sheet material processing is not necessarily stopped.
However, in a case where an effect of the abnormality is assumed to be great, the control unit 120 suspends the sheet material processing. In the suspension of the sheet material processing, the transport of the sheet material is stopped or the sheet material is delivered (No in S41) (S43), and the abnormality of the image forming apparatus 300 is displayed and recovery is commanded appropriately (S44) Further, the control unit 120 determines the effect with respect to the subsequent sheet material processing as needed, and an appropriate processing is performed.
According to the control introduced in Embodiment 5, even in a case where the abnormality occurs in the sheet material information detection apparatus 200, a trouble such as breakage of the sheet material information detection apparatus or members located therearound can be avoided, and an appropriate image forming process can be performed.
Hereinafter, modified examples of Embodiments 1 to 5 will be described.
Examples of the sheet material may include paper (ordinary paper, glossy paper, coat paper, recycled paper, or the like), a film made of a resin etc, and an OHP sheet, and the sheet material mainly refers to a sheet-like image recording medium. A shape of the sheet material may be any shape such as one obtained by being cut into predetermined dimensions (cut paper) or one rolled in a roll form (roll paper). Further, the sheet material may be a single material or a sheet material obtained by bonding two or more sheet materials to each other. In this description, the description is made of the sheet material cut into predetermined dimensions as an example.
The sheet material information includes all the information related to the sheet material required for the sheet material processing. Particularly important elements include the physical property and shape, and various pieces of information related thereto. The various pieces of information include at least one of the following: a thickness of the sheet material, density, elastic modulus, viscosity, vibration characteristic, irregularity, surface roughness, state, deformation state, strength, easiness of elastic deformation and plastic deformation, stretch amount, color tone, color change, and reflectance. deformation (stretching, bending, crushing, damaging, folding, etc.), transmittance, state of curling, permeability of a gas or a liquid, thermal property such as heat diffusivity or heat capacity may also be included. In a case of using paper, the examples of information include information on irregularity of fibers, a filler amount, a coat layer, or the like. A water content gives a great effect to physical characteristics and a shape of the sheet material, so the water content is a particularly important attribute.
Another important sheet material information is information on an embedded component affecting the physical property. A list of examples of the embedded component includes elements such as an ID tag and natural objects such as pressed flowers and leaves. The other examples of the important sheet material information include information on an image which has been formed, adhesion of a foreign substance, dirt, a size and shape of media, a fold at an end unit or the like, a working state such as cutting or drilling, lamination or coating, adhesion of a staple, or the like. Further, there are also other examples of the important information including bonding of some pieces of media to each other in an in-plane direction, and whether or not two or more of them entirely or partially overlap each other.
Examples of the abnormality of the sheet material P include sheet clogging, double-feeding, and feeding of the sheet material of an unexpected thickness or material. The examples include the bending and clogging (hereinafter, referred to as sheet clogging) of the sheet material P, transportation in a state where the plurality of sheet materials P overlap each other (double-feeding), and feeding of the sheet material P of an unexpected thickness or material. In a case where there is the above-mentioned abnormality of the sheet material P, not only accuracy of the sheet material information detection is notably reduced, but also a serious trouble such as damage of the sheet material information detection apparatus 100 or the peripheral members is caused.
The above-mentioned embodiments include the sheet material information detection apparatus for detecting and outputting the sheet material information. In a case where there is abnormality in the sheet material, a part or an entire unit of the sheet material information detection apparatus is retracted. The retraction is to move the part or the entire unit of the sheet material information detection apparatus in a direction in which a distance with respect to the sheet material is enlarged. For a specific example, a distance between the external force application unit and the external force detection unit, which are opposed to each other while sandwiching the transport path for the sheet material, is enlarged. For another example, the external force application unit or the external force detection unit is displaced from the transport path for the sheet material to the outside thereof. For still another example, the fixation of the external force application unit or the external force detection unit is alleviated or released, and when a force is applied from the sheet material, the external force application unit or the external force detection unit can be displaced to the outside of the transport path.
As illustrated in
The above-mentioned components are arranged in the transport path 10 for the sheet material P and are fixed to one of the transport guides 9. Note that, the abnormality sensing unit may partially or entirely be formed of different physical units such as an optical unit and an electrical unit.
In the sheet material information detection apparatus is a method in which an impact force is applied to a sheet material P using an external force application unit 1, and reaction of the sheet material P is received by an external force detection unit 2 and is detected by a pressure-sensitive element 2b. As a result, local bending rigidity and compression rigidity can be detected, and mechanical property of the sheet material can be detected.
For the pressure-sensitive element 2b, an element capable of detecting pressure or acceleration, such as a piezoelectric element, a piezoresistance element, an electrostatic capacity acceleration sensor, or a magnetic sensor is appropriately used.
For the application of the impact force, the external force application unit 1 of a certain mass is allowed to impact the sheet material P in a state where an appropriate speed and acceleration are maintained. A material, shape, mass, impact speed, and acceleration of the external force application unit 1 are appropriately determined according to a type and range of the sheet material P as an object of detection. Desirable examples of paper for use in a copying machine used for detection include ordinary paper, coat paper, bond paper, recycled paper, and resin sheets such as OHP.
The desirable material and shape of the external force application unit 1 are those causing minimum wear due to impacting with the sheet material P or contacting involved therein, and minimum plastic deformation and elastic deformation, and having high toughness and causes no crack. Specifically, as the material, a metal material such as stainless steel is desirably used. As the shape, a spherical shape or a bar shape is desirable, and a distal end portion thereof impacting the sheet material P desirably has a curved surface. By providing the curved surface, even in a case where an impact angle is changed due to vibration of the external force application unit or sheet material P at the time of impact, stable impact application is possible, and local wear is reduced, so an even impact application is realized. A part of the curved surface may be provided with a flat portion. By allowing the flat portion to impact the sheet material, the sheet material at an impact portion is evenly compressed, so an error resulting from unevenness of the sheet material can be reduced.
The mass, the impact speed, and the acceleration of the external force application unit 1 is appropriately determined in consideration to rigidity of the sheet material within a range in which the external force application unit 1 does not leave impression or the like on the sheet material P. A desirable range for the detection of the sheet material (paper) for use in the image forming apparatus 300 is mass of about 1 g to 10 g and impact speed of about 0.1 m/sec to 1 m/sec.
Further, the acceleration at the time of impact is desired to be as small as possible. This is because, even in a case where a moving distance until the external force application unit 1 impacts the sheet material depending on dispersion in thickness of the sheet materials P, fixation accuracy of the sheet material information detection apparatus 100, or the like, the impacting at a stable speed can be realized. While depending on the impact speed, variation in speed of the acceleration is desirably within a range of 5% or less, more desirably, 1% or less for the moving distance of 1 mm. In order to reduce the acceleration, acceleration caused by an acceleration unit, acceleration/deceleration caused by the gravity, and deceleration due to resistance caused by friction or the like are used while appropriately compensating for one another.
The application of the external force through the impact may be performed once or a plurality of times for one time of sheet material information detection. Further, the application may be performed in a plurality of positions at the same time, or may be performed intermittently. In a case where the plurality of times of impact application is performed, it is desirable that by applying impact forces of the same value, the output value be equalized to enhance the accuracy. Further, by applying the impact forces of different values to a single sheet material, a plurality of physical property values of the sheet material can be detected.
There may be provided a mechanism for deflecting or compressing the sheet material P by the external force application. For the mechanism for deflecting the sheet material P, in a position opposing the external force application unit 1 through the intermediation of the sheet member P, a step structure such as a groove structure (recess structure) is provided. For the mechanism for compressing the sheet material P, in a position opposing the external force application unit 1 through the intermediation of the sheet member, an external force receiving member for receiving the external force is provided. The groove structure and the external force receiving member may be integrated to each other, or may be separated from each other.
The sheet material P may be deflected while being supported only at one side or both sides. Further, a part of the sheet surface may be deflected to be a recess. Note that, in a case where, as disclosed in Japanese Patent Application Laid-Open No. 2005-024550, an external force detection mechanism is directly connected to the external force application unit to detect a repulsive force of the sheet material P, the external force receiving member is not necessarily required.
The sheet material has elasticity and flexibility, so displacement according to mechanical property of the sheet material P is caused by the impact force when impact force is impressed. The displacement of the sheet material P is measured by the displacement detection element, and mechanical property of the sheet material P can be detected from a displacement amount, displacement speed, and acceleration of the sheet material. As the displacement detection element, the pressure-sensitive element 2b as described above may be used.
The pressure-sensitive element 2b is bonded to a mechanical displacement member (plate-spring like cantilever or the like) to be brought into contact with the sheet material P, so the displacement can be measured from the output of the pressure-sensitive element 2b. As a matter of course, the displacement of the sheet material P may be measured from transmittance and reflection of light, sound, or the like without mechanical contact by applying the light, sound, or the like to the sheet material P by an optical element, an acoustic element, or the like.
Vibration is applied to the sheet material P, and detection may be performed by the pressure-sensitive element. A reaction from the medium when the vibration is applied to the sheet material is detected by the pressure-sensitive element. For example, the sheet material P is sandwiched between the external force application unit generating vibration and the external force detection unit formed of the pressure-sensitive element, and the vibration is applied to the sheet material P by the external force application unit, and the vibration is detected by the external force detection unit through the sheet material. As a result, attenuation, change in phase, transmission time, and the like of the vibration of the sheet material P are measured to detect mechanical property of the sheet material P. There may be employed various arrangement relationships between the external force application unit and the external force detection unit, and the sheet material P.
In addition, a force of vibration or a frictional force may be detected by applying a transport force as the external force and rubbing a surface of media with a probe. Alternatively, property may be detected by imparting a wave motion such as light or acoustic wave, and detecting a wave motion after reflection or transmission.
The abnormality sensing unit for sensing the abnormality of the sheet material P which is transported detects the case of sheet clogging, double-feeding, feeding of the sheet material of an unexpected thickness or material, or the like. The push-in of the displacement member 11 in a suppression detection unit may be sensed through electrical conduction detection or mechanical pressing detection. Further, the push-in sensing may be performed by an optical detection element (for example, photointerrupter). The detection may be of a contact type as described in Embodiment 2 or a non-contact type.
When the abnormal displacement of the displacement member is detected by the suppression detection unit, the external force application unit or at least a part of the external force detection unit is retracted from the sheet material P interlockingly therewith. The retraction herein means to move the external force application unit or at least a part of the external force detection unit in a direction in which a distance between the external force application unit or at least a part of the external force detection unit, and the sheet material P which are opposed to each other enlarges. The movement may actively be performed by using a driving force, or may passively be performed by releasing the fixation upon application of a force from the sheet material P.
The interlock between the detection of displacement of the displacement member and the retraction movement may electrically be controlled. For example, the abnormality is detected by the electrical conduction detection, and a conduction signal is transmitted to a motor control system to operate a motor, thereby allowing the external force application unit to be retracted to the retraction position. The retraction position in Embodiments 1 and 2 corresponds to a position where the external force application unit 1 is pulled up to the vicinity of an upper dead center of the cam 4 illustrated in
The interlock between the detection of displacement of the displacement member and the retraction movement may mechanically be controlled as described in Embodiment 5. The mechanical control means to release the fixation by driving a releasing mechanism by a suppression force of the displacement member, or the like.
The retraction amount is set to a distance, which does not cause a damage to the sheet material information detection apparatus 100 and the image forming apparatus 300 due to at least passage and impact of the sheet material. Specifically, the retraction is desirably performed to outside a surface of a transport guide 9, which is to be brought into contact with the sheet material P, the transport guide constituting the transport path 10 for the sheet material P. However, in a case where there is provided a mechanism for dissipating a pressure due to the contact with the sheet material P, such as a case where a surface of the member of the sheet material information detection apparatus 100 to be retracted, which is adjacent to the sheet material P, is structured to be a curved surface, protruding of the curved surface into the transport path may not be a problem.
Recovery from the retraction position may automatically be performed. Alternatively, the recovery may actively be performed through a resetting operation by a user or may manually be performed.
In Embodiment 1, the description is made of the image forming apparatus 300. However the sheet material processing apparatus of the present invention is not limited to the image forming apparatus. The image forming apparatus includes an apparatus for recording characters, images, or the like on a sheet material. Among current representative image forming apparatuses, that is, a copying machine, a laser beam printer, and an ink jet printer, there is generally provided a sheet material processing apparatus having a structure in which, as a part of a process, sorting, punching, or stapling for book binding, curl correction, stacking, or the like. As described above, an object of the present invention is aimed at an entire process performed until the medium which is set is discharged from the image forming apparatus 300.
Further, another example of the sheet material processing according to the present invention is to read a content recorded on the sheet material. The content recorded on the sheet material may be of any type or form, including images or characters, stamps, magnetically-recorded data, and data recorded on an embedded element.
Further, other examples of the sheet material processing apparatus of the present invention include an apparatus for transporting a sheet material and reading information recorded on the sheet material (such as so-called document scanner), a feeder apparatus for paper money, tickets, or the like, an apparatus for performing machining such as folding, punching, or the like of the sheet material.
In the image forming apparatus serving as a processing unit, processing conditions for the sheet material P are changed, adjusted, or controlled based on the sheet material information obtained by the sheet material information detection apparatus. An example of the processing conditions include image forming conditions related to transferring of colorant to the medium, the colorant mainly being toner in a case of an electrophotographic printer, and mainly being ink in a case of an ink jet printer. In the image forming apparatus, the image forming conditions are adjusted by changing the image forming conditions or control conditions for the image formation based on the sheet material information.
For example, on the sheet material P having a small thickness, images are formed in a mode suitable for a thin sheet, and on the sheet material P having a large thickness, images are formed in a mode suitable for a thick sheet. For controlling image forming conditions, it is preferable that, first, a transfer amount of the colorant be adjusted. Examples of the transfer amount include a supplying amount of the toner, an adhesion amount of the ink, and the like with respect to the medium. It is preferable that, second, fixing conditions for the colorant be adjusted. Examples of the fixing conditions include a fixing temperature, a fixing pressure, and the like.
Note that, the adjustment of the sheet material processing conditions is not limited to adjustment of arrangement of the images, and adjustment of transfer conditions for the colorant described above. The adjustment of the sheet material processing conditions is performed by a computer control apparatus (processor) for determining the operation of the sheet material processing apparatus by processing input data. The computer control apparatus may be provided in the image forming apparatus 300 or a function thereof may be left to an external computer or the like.
The sheet material processing apparatus according to the present invention can be provided with a processing function dealing with the abnormality of the sheet material P. Specifically, there can be provided a mechanism for manually pulling out the sheet material P from the transport path by releasing the fixation of the components.
In the sheet material information detection apparatus according to the present invention, the sensed abnormality of the sheet material P can be transmitted to the sheet material processing apparatus as one piece of the sheet material information, and a proper processing can be performed therefor. Examples of the processing include, as described in Embodiment 5, stopping of a transport force, shift of various sheet material processing processes to a stopping state, issuing of an alarm, and the like.
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. 2006-178770, filed Jun. 28, 2006, which is hereby incorporated by reference herein in its entirety.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2006-178770 | Jun 2006 | JP | national |
